diff --git a/src/net.cpp b/src/net.cpp
index 26012caf6..ba3fb799a 100644
--- a/src/net.cpp
+++ b/src/net.cpp
@@ -1,3080 +1,3070 @@
 // Copyright (c) 2009-2010 Satoshi Nakamoto
 // Copyright (c) 2009-2016 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #if defined(HAVE_CONFIG_H)
 #include "config/bitcoin-config.h"
 #endif
 
 #include "net.h"
 
 #include "addrman.h"
 #include "chainparams.h"
 #include "clientversion.h"
 #include "config.h"
 #include "consensus/consensus.h"
 #include "crypto/common.h"
 #include "crypto/sha256.h"
 #include "hash.h"
 #include "netbase.h"
 #include "primitives/transaction.h"
 #include "scheduler.h"
 #include "ui_interface.h"
 #include "utilstrencodings.h"
 
 #ifdef WIN32
 #include <string.h>
 #else
 #include <fcntl.h>
 #endif
 
 #ifdef USE_UPNP
 #include <miniupnpc/miniupnpc.h>
 #include <miniupnpc/miniwget.h>
 #include <miniupnpc/upnpcommands.h>
 #include <miniupnpc/upnperrors.h>
 #endif
 
 #include <cmath>
 
 // Dump addresses to peers.dat and banlist.dat every 15 minutes (900s)
 #define DUMP_ADDRESSES_INTERVAL 900
 
 // We add a random period time (0 to 1 seconds) to feeler connections to prevent
 // synchronization.
 #define FEELER_SLEEP_WINDOW 1
 
 #if !defined(HAVE_MSG_NOSIGNAL) && !defined(MSG_NOSIGNAL)
 #define MSG_NOSIGNAL 0
 #endif
 
 // Fix for ancient MinGW versions, that don't have defined these in ws2tcpip.h.
 // Todo: Can be removed when our pull-tester is upgraded to a modern MinGW
 // version.
 #ifdef WIN32
 #ifndef PROTECTION_LEVEL_UNRESTRICTED
 #define PROTECTION_LEVEL_UNRESTRICTED 10
 #endif
 #ifndef IPV6_PROTECTION_LEVEL
 #define IPV6_PROTECTION_LEVEL 23
 #endif
 #endif
 
 static const std::string NET_MESSAGE_COMMAND_OTHER = "*other*";
 
 // SHA256("netgroup")[0:8]
 static const uint64_t RANDOMIZER_ID_NETGROUP = 0x6c0edd8036ef4036ULL;
 // SHA256("localhostnonce")[0:8]
 static const uint64_t RANDOMIZER_ID_LOCALHOSTNONCE = 0xd93e69e2bbfa5735ULL;
 //
 // Global state variables
 //
 bool fDiscover = true;
 bool fListen = true;
 bool fRelayTxes = true;
 CCriticalSection cs_mapLocalHost;
 std::map<CNetAddr, LocalServiceInfo> mapLocalHost;
 static bool vfLimited[NET_MAX] = {};
 
 limitedmap<uint256, int64_t> mapAlreadyAskedFor(MAX_INV_SZ);
 
 // Signals for message handling
 static CNodeSignals g_signals;
 CNodeSignals &GetNodeSignals() {
     return g_signals;
 }
 
 void CConnman::AddOneShot(const std::string &strDest) {
     LOCK(cs_vOneShots);
     vOneShots.push_back(strDest);
 }
 
 unsigned short GetListenPort() {
     return (unsigned short)(gArgs.GetArg("-port", Params().GetDefaultPort()));
 }
 
 // find 'best' local address for a particular peer
 bool GetLocal(CService &addr, const CNetAddr *paddrPeer) {
     if (!fListen) return false;
 
     int nBestScore = -1;
     int nBestReachability = -1;
     {
         LOCK(cs_mapLocalHost);
         for (std::map<CNetAddr, LocalServiceInfo>::iterator it =
                  mapLocalHost.begin();
              it != mapLocalHost.end(); it++) {
             int nScore = (*it).second.nScore;
             int nReachability = (*it).first.GetReachabilityFrom(paddrPeer);
             if (nReachability > nBestReachability ||
                 (nReachability == nBestReachability && nScore > nBestScore)) {
                 addr = CService((*it).first, (*it).second.nPort);
                 nBestReachability = nReachability;
                 nBestScore = nScore;
             }
         }
     }
     return nBestScore >= 0;
 }
 
 //! Convert the pnSeeds6 array into usable address objects.
 static std::vector<CAddress>
 convertSeed6(const std::vector<SeedSpec6> &vSeedsIn) {
     // It'll only connect to one or two seed nodes because once it connects,
     // it'll get a pile of addresses with newer timestamps. Seed nodes are given
     // a random 'last seen time' of between one and two weeks ago.
     const int64_t nOneWeek = 7 * 24 * 60 * 60;
     std::vector<CAddress> vSeedsOut;
     vSeedsOut.reserve(vSeedsIn.size());
     for (std::vector<SeedSpec6>::const_iterator i(vSeedsIn.begin());
          i != vSeedsIn.end(); ++i) {
         struct in6_addr ip;
         memcpy(&ip, i->addr, sizeof(ip));
         CAddress addr(CService(ip, i->port), NODE_NETWORK);
         addr.nTime = GetTime() - GetRand(nOneWeek) - nOneWeek;
         vSeedsOut.push_back(addr);
     }
     return vSeedsOut;
 }
 
 // Get best local address for a particular peer as a CAddress. Otherwise, return
 // the unroutable 0.0.0.0 but filled in with the normal parameters, since the IP
 // may be changed to a useful one by discovery.
 CAddress GetLocalAddress(const CNetAddr *paddrPeer,
                          ServiceFlags nLocalServices) {
     CAddress ret(CService(CNetAddr(), GetListenPort()), NODE_NONE);
     CService addr;
     if (GetLocal(addr, paddrPeer)) {
         ret = CAddress(addr, nLocalServices);
     }
     ret.nTime = GetAdjustedTime();
     return ret;
 }
 
 int GetnScore(const CService &addr) {
     LOCK(cs_mapLocalHost);
     if (mapLocalHost.count(addr) == LOCAL_NONE) {
         return 0;
     }
     return mapLocalHost[addr].nScore;
 }
 
 // Is our peer's addrLocal potentially useful as an external IP source?
 bool IsPeerAddrLocalGood(CNode *pnode) {
     CService addrLocal = pnode->GetAddrLocal();
     return fDiscover && pnode->addr.IsRoutable() && addrLocal.IsRoutable() &&
            !IsLimited(addrLocal.GetNetwork());
 }
 
 // Pushes our own address to a peer.
 void AdvertiseLocal(CNode *pnode) {
     if (fListen && pnode->fSuccessfullyConnected) {
         CAddress addrLocal =
             GetLocalAddress(&pnode->addr, pnode->GetLocalServices());
         // If discovery is enabled, sometimes give our peer the address it tells
         // us that it sees us as in case it has a better idea of our address
         // than we do.
         if (IsPeerAddrLocalGood(pnode) &&
             (!addrLocal.IsRoutable() ||
              GetRand((GetnScore(addrLocal) > LOCAL_MANUAL) ? 8 : 2) == 0)) {
             addrLocal.SetIP(pnode->GetAddrLocal());
         }
         if (addrLocal.IsRoutable()) {
             LogPrint(BCLog::NET, "AdvertiseLocal: advertising address %s\n",
                      addrLocal.ToString());
             FastRandomContext insecure_rand;
             pnode->PushAddress(addrLocal, insecure_rand);
         }
     }
 }
 
 // Learn a new local address.
 bool AddLocal(const CService &addr, int nScore) {
     if (!addr.IsRoutable()) {
         return false;
     }
 
     if (!fDiscover && nScore < LOCAL_MANUAL) {
         return false;
     }
 
     if (IsLimited(addr)) {
         return false;
     }
 
     LogPrintf("AddLocal(%s,%i)\n", addr.ToString(), nScore);
 
     {
         LOCK(cs_mapLocalHost);
         bool fAlready = mapLocalHost.count(addr) > 0;
         LocalServiceInfo &info = mapLocalHost[addr];
         if (!fAlready || nScore >= info.nScore) {
             info.nScore = nScore + (fAlready ? 1 : 0);
             info.nPort = addr.GetPort();
         }
     }
 
     return true;
 }
 
 bool AddLocal(const CNetAddr &addr, int nScore) {
     return AddLocal(CService(addr, GetListenPort()), nScore);
 }
 
 bool RemoveLocal(const CService &addr) {
     LOCK(cs_mapLocalHost);
     LogPrintf("RemoveLocal(%s)\n", addr.ToString());
     mapLocalHost.erase(addr);
     return true;
 }
 
 /** Make a particular network entirely off-limits (no automatic connects to it)
  */
 void SetLimited(enum Network net, bool fLimited) {
     if (net == NET_UNROUTABLE) {
         return;
     }
     LOCK(cs_mapLocalHost);
     vfLimited[net] = fLimited;
 }
 
 bool IsLimited(enum Network net) {
     LOCK(cs_mapLocalHost);
     return vfLimited[net];
 }
 
 bool IsLimited(const CNetAddr &addr) {
     return IsLimited(addr.GetNetwork());
 }
 
 /** vote for a local address */
 bool SeenLocal(const CService &addr) {
     LOCK(cs_mapLocalHost);
     if (mapLocalHost.count(addr) == 0) {
         return false;
     }
     mapLocalHost[addr].nScore++;
     return true;
 }
 
 /** check whether a given address is potentially local */
 bool IsLocal(const CService &addr) {
     LOCK(cs_mapLocalHost);
     return mapLocalHost.count(addr) > 0;
 }
 
 /** check whether a given network is one we can probably connect to */
 bool IsReachable(enum Network net) {
     LOCK(cs_mapLocalHost);
     return !vfLimited[net];
 }
 
 /** check whether a given address is in a network we can probably connect to */
 bool IsReachable(const CNetAddr &addr) {
     enum Network net = addr.GetNetwork();
     return IsReachable(net);
 }
 
 CNode *CConnman::FindNode(const CNetAddr &ip) {
     LOCK(cs_vNodes);
     for (CNode *pnode : vNodes) {
         if ((CNetAddr)pnode->addr == ip) {
             return pnode;
         }
     }
     return nullptr;
 }
 
 CNode *CConnman::FindNode(const CSubNet &subNet) {
     LOCK(cs_vNodes);
     for (CNode *pnode : vNodes) {
         if (subNet.Match((CNetAddr)pnode->addr)) {
             return pnode;
         }
     }
     return nullptr;
 }
 
 CNode *CConnman::FindNode(const std::string &addrName) {
     LOCK(cs_vNodes);
     for (CNode *pnode : vNodes) {
         if (pnode->GetAddrName() == addrName) {
             return pnode;
         }
     }
     return nullptr;
 }
 
 CNode *CConnman::FindNode(const CService &addr) {
     LOCK(cs_vNodes);
     for (CNode *pnode : vNodes) {
         if ((CService)pnode->addr == addr) {
             return pnode;
         }
     }
     return nullptr;
 }
 
 bool CConnman::CheckIncomingNonce(uint64_t nonce) {
     LOCK(cs_vNodes);
     for (CNode *pnode : vNodes) {
         if (!pnode->fSuccessfullyConnected && !pnode->fInbound &&
             pnode->GetLocalNonce() == nonce)
             return false;
     }
     return true;
 }
 
 CNode *CConnman::ConnectNode(CAddress addrConnect, const char *pszDest,
                              bool fCountFailure) {
     if (pszDest == nullptr) {
         if (IsLocal(addrConnect)) {
             return nullptr;
         }
 
         // Look for an existing connection
         CNode *pnode = FindNode((CService)addrConnect);
         if (pnode) {
             LogPrintf("Failed to open new connection, already connected\n");
             return nullptr;
         }
     }
 
     /// debug print
     LogPrint(BCLog::NET, "trying connection %s lastseen=%.1fhrs\n",
              pszDest ? pszDest : addrConnect.ToString(),
              pszDest
                  ? 0.0
                  : (double)(GetAdjustedTime() - addrConnect.nTime) / 3600.0);
 
     // Connect
     SOCKET hSocket;
     bool proxyConnectionFailed = false;
     if (pszDest ? ConnectSocketByName(addrConnect, hSocket, pszDest,
                                       config->GetChainParams().GetDefaultPort(),
                                       nConnectTimeout, &proxyConnectionFailed)
                 : ConnectSocket(addrConnect, hSocket, nConnectTimeout,
                                 &proxyConnectionFailed)) {
         if (!IsSelectableSocket(hSocket)) {
             LogPrintf("Cannot create connection: non-selectable socket created "
                       "(fd >= FD_SETSIZE ?)\n");
             CloseSocket(hSocket);
             return nullptr;
         }
 
         if (pszDest && addrConnect.IsValid()) {
             // It is possible that we already have a connection to the IP/port
             // pszDest resolved to. In that case, drop the connection that was
             // just created, and return the existing CNode instead. Also store
             // the name we used to connect in that CNode, so that future
             // FindNode() calls to that name catch this early.
             LOCK(cs_vNodes);
             CNode *pnode = FindNode((CService)addrConnect);
             if (pnode) {
                 pnode->MaybeSetAddrName(std::string(pszDest));
                 CloseSocket(hSocket);
                 LogPrintf("Failed to open new connection, already connected\n");
                 return nullptr;
             }
         }
 
         addrman.Attempt(addrConnect, fCountFailure);
 
         // Add node
         NodeId id = GetNewNodeId();
         uint64_t nonce =
             GetDeterministicRandomizer(RANDOMIZER_ID_LOCALHOSTNONCE)
                 .Write(id)
                 .Finalize();
         CNode *pnode =
             new CNode(id, nLocalServices, GetBestHeight(), hSocket, addrConnect,
                       CalculateKeyedNetGroup(addrConnect), nonce,
                       pszDest ? pszDest : "", false);
         pnode->nServicesExpected =
             ServiceFlags(addrConnect.nServices & nRelevantServices);
         pnode->AddRef();
 
         return pnode;
     } else if (!proxyConnectionFailed) {
         // If connecting to the node failed, and failure is not caused by a
         // problem connecting to the proxy, mark this as an attempt.
         addrman.Attempt(addrConnect, fCountFailure);
     }
 
     return nullptr;
 }
 
 void CConnman::DumpBanlist() {
     // Clean unused entries (if bantime has expired)
     SweepBanned();
 
     if (!BannedSetIsDirty()) {
         return;
     }
 
     int64_t nStart = GetTimeMillis();
 
     CBanDB bandb(config->GetChainParams());
     banmap_t banmap;
     GetBanned(banmap);
     if (bandb.Write(banmap)) {
         SetBannedSetDirty(false);
     }
 
     LogPrint(BCLog::NET,
              "Flushed %d banned node ips/subnets to banlist.dat  %dms\n",
              banmap.size(), GetTimeMillis() - nStart);
 }
 
 void CNode::CloseSocketDisconnect() {
     fDisconnect = true;
     LOCK(cs_hSocket);
     if (hSocket != INVALID_SOCKET) {
         LogPrint(BCLog::NET, "disconnecting peer=%d\n", id);
         CloseSocket(hSocket);
     }
 }
 
 void CConnman::ClearBanned() {
     {
         LOCK(cs_setBanned);
         setBanned.clear();
         setBannedIsDirty = true;
     }
 
     // Store banlist to disk.
     DumpBanlist();
     if (clientInterface) {
         clientInterface->BannedListChanged();
     }
 }
 
 bool CConnman::IsBanned(CNetAddr ip) {
     LOCK(cs_setBanned);
 
     bool fResult = false;
     for (banmap_t::iterator it = setBanned.begin(); it != setBanned.end();
          it++) {
         CSubNet subNet = (*it).first;
         CBanEntry banEntry = (*it).second;
 
         if (subNet.Match(ip) && GetTime() < banEntry.nBanUntil) {
             fResult = true;
         }
     }
 
     return fResult;
 }
 
 bool CConnman::IsBanned(CSubNet subnet) {
     LOCK(cs_setBanned);
 
     bool fResult = false;
     banmap_t::iterator i = setBanned.find(subnet);
     if (i != setBanned.end()) {
         CBanEntry banEntry = (*i).second;
         if (GetTime() < banEntry.nBanUntil) {
             fResult = true;
         }
     }
 
     return fResult;
 }
 
 void CConnman::Ban(const CNetAddr &addr, const BanReason &banReason,
                    int64_t bantimeoffset, bool sinceUnixEpoch) {
     CSubNet subNet(addr);
     Ban(subNet, banReason, bantimeoffset, sinceUnixEpoch);
 }
 
 void CConnman::Ban(const CSubNet &subNet, const BanReason &banReason,
                    int64_t bantimeoffset, bool sinceUnixEpoch) {
     CBanEntry banEntry(GetTime());
     banEntry.banReason = banReason;
     if (bantimeoffset <= 0) {
         bantimeoffset = gArgs.GetArg("-bantime", DEFAULT_MISBEHAVING_BANTIME);
         sinceUnixEpoch = false;
     }
     banEntry.nBanUntil = (sinceUnixEpoch ? 0 : GetTime()) + bantimeoffset;
 
     {
         LOCK(cs_setBanned);
         if (setBanned[subNet].nBanUntil < banEntry.nBanUntil) {
             setBanned[subNet] = banEntry;
             setBannedIsDirty = true;
         } else {
             return;
         }
     }
 
     if (clientInterface) {
         clientInterface->BannedListChanged();
     }
 
     {
         LOCK(cs_vNodes);
         for (CNode *pnode : vNodes) {
             if (subNet.Match((CNetAddr)pnode->addr)) {
                 pnode->fDisconnect = true;
             }
         }
     }
 
     if (banReason == BanReasonManuallyAdded) {
         // Store banlist to disk immediately if user requested ban.
         DumpBanlist();
     }
 }
 
 bool CConnman::Unban(const CNetAddr &addr) {
     CSubNet subNet(addr);
     return Unban(subNet);
 }
 
 bool CConnman::Unban(const CSubNet &subNet) {
     {
         LOCK(cs_setBanned);
         if (!setBanned.erase(subNet)) {
             return false;
         }
         setBannedIsDirty = true;
     }
 
     if (clientInterface) {
         clientInterface->BannedListChanged();
     }
 
     // Store banlist to disk immediately.
     DumpBanlist();
     return true;
 }
 
 void CConnman::GetBanned(banmap_t &banMap) {
     LOCK(cs_setBanned);
     // Sweep the banlist so expired bans are not returned
     SweepBanned();
     // Create a thread safe copy.
     banMap = setBanned;
 }
 
 void CConnman::SetBanned(const banmap_t &banMap) {
     LOCK(cs_setBanned);
     setBanned = banMap;
     setBannedIsDirty = true;
 }
 
 void CConnman::SweepBanned() {
     int64_t now = GetTime();
 
     LOCK(cs_setBanned);
     banmap_t::iterator it = setBanned.begin();
     while (it != setBanned.end()) {
         CSubNet subNet = (*it).first;
         CBanEntry banEntry = (*it).second;
         if (now > banEntry.nBanUntil) {
             setBanned.erase(it++);
             setBannedIsDirty = true;
             LogPrint(BCLog::NET,
                      "%s: Removed banned node ip/subnet from banlist.dat: %s\n",
                      __func__, subNet.ToString());
         } else {
             ++it;
         }
     }
 }
 
 bool CConnman::BannedSetIsDirty() {
     LOCK(cs_setBanned);
     return setBannedIsDirty;
 }
 
 void CConnman::SetBannedSetDirty(bool dirty) {
     // Reuse setBanned lock for the isDirty flag.
     LOCK(cs_setBanned);
     setBannedIsDirty = dirty;
 }
 
 bool CConnman::IsWhitelistedRange(const CNetAddr &addr) {
     LOCK(cs_vWhitelistedRange);
     for (const CSubNet &subnet : vWhitelistedRange) {
         if (subnet.Match(addr)) {
             return true;
         }
     }
     return false;
 }
 
 void CConnman::AddWhitelistedRange(const CSubNet &subnet) {
     LOCK(cs_vWhitelistedRange);
     vWhitelistedRange.push_back(subnet);
 }
 
 std::string CNode::GetAddrName() const {
     LOCK(cs_addrName);
     return addrName;
 }
 
 void CNode::MaybeSetAddrName(const std::string &addrNameIn) {
     LOCK(cs_addrName);
     if (addrName.empty()) {
         addrName = addrNameIn;
     }
 }
 
 CService CNode::GetAddrLocal() const {
     LOCK(cs_addrLocal);
     return addrLocal;
 }
 
 void CNode::SetAddrLocal(const CService &addrLocalIn) {
     LOCK(cs_addrLocal);
     if (addrLocal.IsValid()) {
         error("Addr local already set for node: %i. Refusing to change from %s "
               "to %s",
               id, addrLocal.ToString(), addrLocalIn.ToString());
     } else {
         addrLocal = addrLocalIn;
     }
 }
 
 #undef X
 #define X(name) stats.name = name
 void CNode::copyStats(CNodeStats &stats) {
     stats.nodeid = this->GetId();
     X(nServices);
     X(addr);
     {
         LOCK(cs_filter);
         X(fRelayTxes);
     }
     X(nLastSend);
     X(nLastRecv);
     X(nTimeConnected);
     X(nTimeOffset);
     stats.addrName = GetAddrName();
     X(nVersion);
     {
         LOCK(cs_SubVer);
         X(cleanSubVer);
     }
     X(fInbound);
     X(fAddnode);
     X(nStartingHeight);
     {
         LOCK(cs_vSend);
         X(mapSendBytesPerMsgCmd);
         X(nSendBytes);
     }
     {
         LOCK(cs_vRecv);
         X(mapRecvBytesPerMsgCmd);
         X(nRecvBytes);
     }
     X(fWhitelisted);
 
     // It is common for nodes with good ping times to suddenly become lagged,
     // due to a new block arriving or other large transfer. Merely reporting
     // pingtime might fool the caller into thinking the node was still
     // responsive, since pingtime does not update until the ping is complete,
     // which might take a while. So, if a ping is taking an unusually long time
     // in flight, the caller can immediately detect that this is happening.
     int64_t nPingUsecWait = 0;
     if ((0 != nPingNonceSent) && (0 != nPingUsecStart)) {
         nPingUsecWait = GetTimeMicros() - nPingUsecStart;
     }
 
     // Raw ping time is in microseconds, but show it to user as whole seconds
     // (Bitcoin users should be well used to small numbers with many decimal
     // places by now :)
     stats.dPingTime = ((double(nPingUsecTime)) / 1e6);
     stats.dMinPing = ((double(nMinPingUsecTime)) / 1e6);
     stats.dPingWait = ((double(nPingUsecWait)) / 1e6);
 
     // Leave string empty if addrLocal invalid (not filled in yet)
     CService addrLocalUnlocked = GetAddrLocal();
     stats.addrLocal =
         addrLocalUnlocked.IsValid() ? addrLocalUnlocked.ToString() : "";
 }
 #undef X
 
 static bool IsOversizedMessage(const Config &config, const CNetMessage &msg) {
     if (!msg.in_data) {
         // Header only, cannot be oversized.
         return false;
     }
 
-    // If the message doesn't not contain a block content, check against
-    // MAX_PROTOCOL_MESSAGE_LENGTH.
-    if (msg.hdr.nMessageSize > MAX_PROTOCOL_MESSAGE_LENGTH &&
-        !NetMsgType::IsBlockLike(msg.hdr.GetCommand())) {
-        return true;
-    }
-
-    // Scale the maximum accepted size with the block size.
-    if (msg.hdr.nMessageSize > 2 * config.GetMaxBlockSize()) {
-        return true;
-    }
-
-    return false;
+    return msg.hdr.IsOversized(config);
 }
 
 bool CNode::ReceiveMsgBytes(const Config &config, const char *pch,
                             unsigned int nBytes, bool &complete) {
     complete = false;
     int64_t nTimeMicros = GetTimeMicros();
     LOCK(cs_vRecv);
     nLastRecv = nTimeMicros / 1000000;
     nRecvBytes += nBytes;
     while (nBytes > 0) {
         // Get current incomplete message, or create a new one.
         if (vRecvMsg.empty() || vRecvMsg.back().complete()) {
             vRecvMsg.push_back(CNetMessage(Params().NetMagic(), SER_NETWORK,
                                            INIT_PROTO_VERSION));
         }
 
         CNetMessage &msg = vRecvMsg.back();
 
         // Absorb network data.
         int handled;
         if (!msg.in_data) {
-            handled = msg.readHeader(pch, nBytes);
+            handled = msg.readHeader(config, pch, nBytes);
         } else {
             handled = msg.readData(pch, nBytes);
         }
 
         if (handled < 0) {
             return false;
         }
 
         if (IsOversizedMessage(config, msg)) {
             LogPrint(BCLog::NET,
                      "Oversized message from peer=%i, disconnecting\n",
                      GetId());
             return false;
         }
 
         pch += handled;
         nBytes -= handled;
 
         if (msg.complete()) {
             // Store received bytes per message command to prevent a memory DOS,
             // only allow valid commands.
             mapMsgCmdSize::iterator i =
                 mapRecvBytesPerMsgCmd.find(msg.hdr.pchCommand);
             if (i == mapRecvBytesPerMsgCmd.end()) {
                 i = mapRecvBytesPerMsgCmd.find(NET_MESSAGE_COMMAND_OTHER);
             }
 
             assert(i != mapRecvBytesPerMsgCmd.end());
             i->second += msg.hdr.nMessageSize + CMessageHeader::HEADER_SIZE;
 
             msg.nTime = nTimeMicros;
             complete = true;
         }
     }
 
     return true;
 }
 
 void CNode::SetSendVersion(int nVersionIn) {
     // Send version may only be changed in the version message, and only one
     // version message is allowed per session. We can therefore treat this value
     // as const and even atomic as long as it's only used once a version message
     // has been successfully processed. Any attempt to set this twice is an
     // error.
     if (nSendVersion != 0) {
         error("Send version already set for node: %i. Refusing to change from "
               "%i to %i",
               id, nSendVersion, nVersionIn);
     } else {
         nSendVersion = nVersionIn;
     }
 }
 
 int CNode::GetSendVersion() const {
     // The send version should always be explicitly set to INIT_PROTO_VERSION
     // rather than using this value until SetSendVersion has been called.
     if (nSendVersion == 0) {
         error("Requesting unset send version for node: %i. Using %i", id,
               INIT_PROTO_VERSION);
         return INIT_PROTO_VERSION;
     }
     return nSendVersion;
 }
 
-int CNetMessage::readHeader(const char *pch, unsigned int nBytes) {
+int CNetMessage::readHeader(const Config &config, const char *pch,
+                            unsigned int nBytes) {
     // copy data to temporary parsing buffer
     unsigned int nRemaining = 24 - nHdrPos;
     unsigned int nCopy = std::min(nRemaining, nBytes);
 
     memcpy(&hdrbuf[nHdrPos], pch, nCopy);
     nHdrPos += nCopy;
 
     // if header incomplete, exit
     if (nHdrPos < 24) {
         return nCopy;
     }
 
     // deserialize to CMessageHeader
     try {
         hdrbuf >> hdr;
     } catch (const std::exception &) {
         return -1;
     }
 
-    // reject messages larger than MAX_SIZE
-    if (hdr.nMessageSize > MAX_SIZE) {
+    // Reject oversized messages
+    if (hdr.IsOversized(config)) {
+        LogPrint(BCLog::NET, "Oversized header detected\n");
         return -1;
     }
 
     // switch state to reading message data
     in_data = true;
 
     return nCopy;
 }
 
 int CNetMessage::readData(const char *pch, unsigned int nBytes) {
     unsigned int nRemaining = hdr.nMessageSize - nDataPos;
     unsigned int nCopy = std::min(nRemaining, nBytes);
 
     if (vRecv.size() < nDataPos + nCopy) {
         // Allocate up to 256 KiB ahead, but never more than the total message
         // size.
         vRecv.resize(std::min(hdr.nMessageSize, nDataPos + nCopy + 256 * 1024));
     }
 
     hasher.Write((const uint8_t *)pch, nCopy);
     memcpy(&vRecv[nDataPos], pch, nCopy);
     nDataPos += nCopy;
 
     return nCopy;
 }
 
 const uint256 &CNetMessage::GetMessageHash() const {
     assert(complete());
     if (data_hash.IsNull()) {
         hasher.Finalize(data_hash.begin());
     }
     return data_hash;
 }
 
 // requires LOCK(cs_vSend)
 size_t CConnman::SocketSendData(CNode *pnode) const {
     AssertLockHeld(pnode->cs_vSend);
     size_t nSentSize = 0;
     size_t nMsgCount = 0;
 
     for (const auto &data : pnode->vSendMsg) {
         assert(data.size() > pnode->nSendOffset);
         int nBytes = 0;
 
         {
             LOCK(pnode->cs_hSocket);
             if (pnode->hSocket == INVALID_SOCKET) {
                 break;
             }
 
             nBytes = send(pnode->hSocket,
                           reinterpret_cast<const char *>(data.data()) +
                               pnode->nSendOffset,
                           data.size() - pnode->nSendOffset,
                           MSG_NOSIGNAL | MSG_DONTWAIT);
         }
 
         if (nBytes == 0) {
             // couldn't send anything at all
             break;
         }
 
         if (nBytes < 0) {
             // error
             int nErr = WSAGetLastError();
             if (nErr != WSAEWOULDBLOCK && nErr != WSAEMSGSIZE &&
                 nErr != WSAEINTR && nErr != WSAEINPROGRESS) {
                 LogPrintf("socket send error %s\n", NetworkErrorString(nErr));
                 pnode->CloseSocketDisconnect();
             }
 
             break;
         }
 
         assert(nBytes > 0);
         pnode->nLastSend = GetSystemTimeInSeconds();
         pnode->nSendBytes += nBytes;
         pnode->nSendOffset += nBytes;
         nSentSize += nBytes;
         if (pnode->nSendOffset != data.size()) {
             // could not send full message; stop sending more
             break;
         }
 
         pnode->nSendOffset = 0;
         pnode->nSendSize -= data.size();
         pnode->fPauseSend = pnode->nSendSize > nSendBufferMaxSize;
         nMsgCount++;
     }
 
     pnode->vSendMsg.erase(pnode->vSendMsg.begin(),
                           pnode->vSendMsg.begin() + nMsgCount);
 
     if (pnode->vSendMsg.empty()) {
         assert(pnode->nSendOffset == 0);
         assert(pnode->nSendSize == 0);
     }
 
     return nSentSize;
 }
 
 struct NodeEvictionCandidate {
     NodeId id;
     int64_t nTimeConnected;
     int64_t nMinPingUsecTime;
     int64_t nLastBlockTime;
     int64_t nLastTXTime;
     bool fRelevantServices;
     bool fRelayTxes;
     bool fBloomFilter;
     CAddress addr;
     uint64_t nKeyedNetGroup;
 };
 
 static bool ReverseCompareNodeMinPingTime(const NodeEvictionCandidate &a,
                                           const NodeEvictionCandidate &b) {
     return a.nMinPingUsecTime > b.nMinPingUsecTime;
 }
 
 static bool ReverseCompareNodeTimeConnected(const NodeEvictionCandidate &a,
                                             const NodeEvictionCandidate &b) {
     return a.nTimeConnected > b.nTimeConnected;
 }
 
 static bool CompareNetGroupKeyed(const NodeEvictionCandidate &a,
                                  const NodeEvictionCandidate &b) {
     return a.nKeyedNetGroup < b.nKeyedNetGroup;
 }
 
 static bool CompareNodeBlockTime(const NodeEvictionCandidate &a,
                                  const NodeEvictionCandidate &b) {
     // There is a fall-through here because it is common for a node to have many
     // peers which have not yet relayed a block.
     if (a.nLastBlockTime != b.nLastBlockTime) {
         return a.nLastBlockTime < b.nLastBlockTime;
     }
 
     if (a.fRelevantServices != b.fRelevantServices) {
         return b.fRelevantServices;
     }
 
     return a.nTimeConnected > b.nTimeConnected;
 }
 
 static bool CompareNodeTXTime(const NodeEvictionCandidate &a,
                               const NodeEvictionCandidate &b) {
     // There is a fall-through here because it is common for a node to have more
     // than a few peers that have not yet relayed txn.
     if (a.nLastTXTime != b.nLastTXTime) {
         return a.nLastTXTime < b.nLastTXTime;
     }
 
     if (a.fRelayTxes != b.fRelayTxes) {
         return b.fRelayTxes;
     }
 
     if (a.fBloomFilter != b.fBloomFilter) {
         return a.fBloomFilter;
     }
 
     return a.nTimeConnected > b.nTimeConnected;
 }
 
 /**
  * Try to find a connection to evict when the node is full. Extreme care must be
  * taken to avoid opening the node to attacker triggered network partitioning.
  * The strategy used here is to protect a small number of peers for each of
  * several distinct characteristics which are difficult to forge. In order to
  * partition a node the attacker must be simultaneously better at all of them
  * than honest peers.
  */
 bool CConnman::AttemptToEvictConnection() {
     std::vector<NodeEvictionCandidate> vEvictionCandidates;
     {
         LOCK(cs_vNodes);
 
         for (CNode *node : vNodes) {
             if (node->fWhitelisted || !node->fInbound || node->fDisconnect) {
                 continue;
             }
             NodeEvictionCandidate candidate = {
                 node->id,
                 node->nTimeConnected,
                 node->nMinPingUsecTime,
                 node->nLastBlockTime,
                 node->nLastTXTime,
                 (node->nServices & nRelevantServices) == nRelevantServices,
                 node->fRelayTxes,
                 node->pfilter != nullptr,
                 node->addr,
                 node->nKeyedNetGroup};
             vEvictionCandidates.push_back(candidate);
         }
     }
 
     if (vEvictionCandidates.empty()) {
         return false;
     }
 
     // Protect connections with certain characteristics
 
     // Deterministically select 4 peers to protect by netgroup. An attacker
     // cannot predict which netgroups will be protected.
     std::sort(vEvictionCandidates.begin(), vEvictionCandidates.end(),
               CompareNetGroupKeyed);
     vEvictionCandidates.erase(
         vEvictionCandidates.end() -
             std::min(4, static_cast<int>(vEvictionCandidates.size())),
         vEvictionCandidates.end());
 
     if (vEvictionCandidates.empty()) {
         return false;
     }
 
     // Protect the 8 nodes with the lowest minimum ping time. An attacker cannot
     // manipulate this metric without physically moving nodes closer to the
     // target.
     std::sort(vEvictionCandidates.begin(), vEvictionCandidates.end(),
               ReverseCompareNodeMinPingTime);
     vEvictionCandidates.erase(
         vEvictionCandidates.end() -
             std::min(8, static_cast<int>(vEvictionCandidates.size())),
         vEvictionCandidates.end());
 
     if (vEvictionCandidates.empty()) {
         return false;
     }
 
     // Protect 4 nodes that most recently sent us transactions. An attacker
     // cannot manipulate this metric without performing useful work.
     std::sort(vEvictionCandidates.begin(), vEvictionCandidates.end(),
               CompareNodeTXTime);
     vEvictionCandidates.erase(
         vEvictionCandidates.end() -
             std::min(4, static_cast<int>(vEvictionCandidates.size())),
         vEvictionCandidates.end());
 
     if (vEvictionCandidates.empty()) {
         return false;
     }
 
     // Protect 4 nodes that most recently sent us blocks. An attacker cannot
     // manipulate this metric without performing useful work.
     std::sort(vEvictionCandidates.begin(), vEvictionCandidates.end(),
               CompareNodeBlockTime);
     vEvictionCandidates.erase(
         vEvictionCandidates.end() -
             std::min(4, static_cast<int>(vEvictionCandidates.size())),
         vEvictionCandidates.end());
 
     if (vEvictionCandidates.empty()) {
         return false;
     }
 
     // Protect the half of the remaining nodes which have been connected the
     // longest. This replicates the non-eviction implicit behavior, and
     // precludes attacks that start later.
     std::sort(vEvictionCandidates.begin(), vEvictionCandidates.end(),
               ReverseCompareNodeTimeConnected);
     vEvictionCandidates.erase(
         vEvictionCandidates.end() -
             static_cast<int>(vEvictionCandidates.size() / 2),
         vEvictionCandidates.end());
 
     if (vEvictionCandidates.empty()) {
         return false;
     }
 
     // Identify the network group with the most connections and youngest member.
     // (vEvictionCandidates is already sorted by reverse connect time)
     uint64_t naMostConnections;
     unsigned int nMostConnections = 0;
     int64_t nMostConnectionsTime = 0;
     std::map<uint64_t, std::vector<NodeEvictionCandidate>> mapNetGroupNodes;
     for (const NodeEvictionCandidate &node : vEvictionCandidates) {
         mapNetGroupNodes[node.nKeyedNetGroup].push_back(node);
         int64_t grouptime =
             mapNetGroupNodes[node.nKeyedNetGroup][0].nTimeConnected;
         size_t groupsize = mapNetGroupNodes[node.nKeyedNetGroup].size();
 
         if (groupsize > nMostConnections ||
             (groupsize == nMostConnections &&
              grouptime > nMostConnectionsTime)) {
             nMostConnections = groupsize;
             nMostConnectionsTime = grouptime;
             naMostConnections = node.nKeyedNetGroup;
         }
     }
 
     // Reduce to the network group with the most connections
     vEvictionCandidates = std::move(mapNetGroupNodes[naMostConnections]);
 
     // Disconnect from the network group with the most connections
     NodeId evicted = vEvictionCandidates.front().id;
     LOCK(cs_vNodes);
     for (std::vector<CNode *>::const_iterator it(vNodes.begin());
          it != vNodes.end(); ++it) {
         if ((*it)->GetId() == evicted) {
             (*it)->fDisconnect = true;
             return true;
         }
     }
     return false;
 }
 
 void CConnman::AcceptConnection(const ListenSocket &hListenSocket) {
     struct sockaddr_storage sockaddr;
     socklen_t len = sizeof(sockaddr);
     SOCKET hSocket =
         accept(hListenSocket.socket, (struct sockaddr *)&sockaddr, &len);
     CAddress addr;
     int nInbound = 0;
     int nMaxInbound = nMaxConnections - (nMaxOutbound + nMaxFeeler);
 
     if (hSocket != INVALID_SOCKET) {
         if (!addr.SetSockAddr((const struct sockaddr *)&sockaddr)) {
             LogPrintf("Warning: Unknown socket family\n");
         }
     }
 
     bool whitelisted = hListenSocket.whitelisted || IsWhitelistedRange(addr);
     {
         LOCK(cs_vNodes);
         for (CNode *pnode : vNodes) {
             if (pnode->fInbound) {
                 nInbound++;
             }
         }
     }
 
     if (hSocket == INVALID_SOCKET) {
         int nErr = WSAGetLastError();
         if (nErr != WSAEWOULDBLOCK) {
             LogPrintf("socket error accept failed: %s\n",
                       NetworkErrorString(nErr));
         }
         return;
     }
 
     if (!fNetworkActive) {
         LogPrintf("connection from %s dropped: not accepting new connections\n",
                   addr.ToString());
         CloseSocket(hSocket);
         return;
     }
 
     if (!IsSelectableSocket(hSocket)) {
         LogPrintf("connection from %s dropped: non-selectable socket\n",
                   addr.ToString());
         CloseSocket(hSocket);
         return;
     }
 
     // According to the internet TCP_NODELAY is not carried into accepted
     // sockets on all platforms.  Set it again here just to be sure.
     int set = 1;
 #ifdef WIN32
     setsockopt(hSocket, IPPROTO_TCP, TCP_NODELAY, (const char *)&set,
                sizeof(int));
 #else
     setsockopt(hSocket, IPPROTO_TCP, TCP_NODELAY, (void *)&set, sizeof(int));
 #endif
 
     if (IsBanned(addr) && !whitelisted) {
         LogPrintf("connection from %s dropped (banned)\n", addr.ToString());
         CloseSocket(hSocket);
         return;
     }
 
     if (nInbound >= nMaxInbound) {
         if (!AttemptToEvictConnection()) {
             // No connection to evict, disconnect the new connection
             LogPrint(BCLog::NET, "failed to find an eviction candidate - "
                                  "connection dropped (full)\n");
             CloseSocket(hSocket);
             return;
         }
     }
 
     NodeId id = GetNewNodeId();
     uint64_t nonce = GetDeterministicRandomizer(RANDOMIZER_ID_LOCALHOSTNONCE)
                          .Write(id)
                          .Finalize();
 
     CNode *pnode = new CNode(id, nLocalServices, GetBestHeight(), hSocket, addr,
                              CalculateKeyedNetGroup(addr), nonce, "", true);
     pnode->AddRef();
     pnode->fWhitelisted = whitelisted;
 
     GetNodeSignals().InitializeNode(*config, pnode, *this);
 
     LogPrint(BCLog::NET, "connection from %s accepted\n", addr.ToString());
 
     {
         LOCK(cs_vNodes);
         vNodes.push_back(pnode);
     }
 }
 
 void CConnman::ThreadSocketHandler() {
     unsigned int nPrevNodeCount = 0;
     while (!interruptNet) {
         //
         // Disconnect nodes
         //
         {
             LOCK(cs_vNodes);
             // Disconnect unused nodes
             std::vector<CNode *> vNodesCopy = vNodes;
             for (CNode *pnode : vNodesCopy) {
                 if (pnode->fDisconnect) {
                     // remove from vNodes
                     vNodes.erase(remove(vNodes.begin(), vNodes.end(), pnode),
                                  vNodes.end());
 
                     // release outbound grant (if any)
                     pnode->grantOutbound.Release();
 
                     // close socket and cleanup
                     pnode->CloseSocketDisconnect();
 
                     // hold in disconnected pool until all refs are released
                     pnode->Release();
                     vNodesDisconnected.push_back(pnode);
                 }
             }
         }
         {
             // Delete disconnected nodes
             std::list<CNode *> vNodesDisconnectedCopy = vNodesDisconnected;
             for (CNode *pnode : vNodesDisconnectedCopy) {
                 // wait until threads are done using it
                 if (pnode->GetRefCount() <= 0) {
                     bool fDelete = false;
                     {
                         TRY_LOCK(pnode->cs_inventory, lockInv);
                         if (lockInv) {
                             TRY_LOCK(pnode->cs_vSend, lockSend);
                             if (lockSend) {
                                 fDelete = true;
                             }
                         }
                     }
                     if (fDelete) {
                         vNodesDisconnected.remove(pnode);
                         DeleteNode(pnode);
                     }
                 }
             }
         }
         size_t vNodesSize;
         {
             LOCK(cs_vNodes);
             vNodesSize = vNodes.size();
         }
         if (vNodesSize != nPrevNodeCount) {
             nPrevNodeCount = vNodesSize;
             if (clientInterface) {
                 clientInterface->NotifyNumConnectionsChanged(nPrevNodeCount);
             }
         }
 
         //
         // Find which sockets have data to receive
         //
         struct timeval timeout;
         timeout.tv_sec = 0;
         // Frequency to poll pnode->vSend
         timeout.tv_usec = 50000;
 
         fd_set fdsetRecv;
         fd_set fdsetSend;
         fd_set fdsetError;
         FD_ZERO(&fdsetRecv);
         FD_ZERO(&fdsetSend);
         FD_ZERO(&fdsetError);
         SOCKET hSocketMax = 0;
         bool have_fds = false;
 
         for (const ListenSocket &hListenSocket : vhListenSocket) {
             FD_SET(hListenSocket.socket, &fdsetRecv);
             hSocketMax = std::max(hSocketMax, hListenSocket.socket);
             have_fds = true;
         }
 
         {
             LOCK(cs_vNodes);
             for (CNode *pnode : vNodes) {
                 // Implement the following logic:
                 // * If there is data to send, select() for sending data. As
                 // this only happens when optimistic write failed, we choose to
                 // first drain the write buffer in this case before receiving
                 // more. This avoids needlessly queueing received data, if the
                 // remote peer is not themselves receiving data. This means
                 // properly utilizing TCP flow control signalling.
                 // * Otherwise, if there is space left in the receive buffer,
                 // select() for receiving data.
                 // * Hand off all complete messages to the processor, to be
                 // handled without blocking here.
 
                 bool select_recv = !pnode->fPauseRecv;
                 bool select_send;
                 {
                     LOCK(pnode->cs_vSend);
                     select_send = !pnode->vSendMsg.empty();
                 }
 
                 LOCK(pnode->cs_hSocket);
                 if (pnode->hSocket == INVALID_SOCKET) {
                     continue;
                 }
 
                 FD_SET(pnode->hSocket, &fdsetError);
                 hSocketMax = std::max(hSocketMax, pnode->hSocket);
                 have_fds = true;
 
                 if (select_send) {
                     FD_SET(pnode->hSocket, &fdsetSend);
                     continue;
                 }
                 if (select_recv) {
                     FD_SET(pnode->hSocket, &fdsetRecv);
                 }
             }
         }
 
         int nSelect = select(have_fds ? hSocketMax + 1 : 0, &fdsetRecv,
                              &fdsetSend, &fdsetError, &timeout);
         if (interruptNet) {
             return;
         }
 
         if (nSelect == SOCKET_ERROR) {
             if (have_fds) {
                 int nErr = WSAGetLastError();
                 LogPrintf("socket select error %s\n", NetworkErrorString(nErr));
                 for (unsigned int i = 0; i <= hSocketMax; i++) {
                     FD_SET(i, &fdsetRecv);
                 }
             }
             FD_ZERO(&fdsetSend);
             FD_ZERO(&fdsetError);
             if (!interruptNet.sleep_for(
                     std::chrono::milliseconds(timeout.tv_usec / 1000))) {
                 return;
             }
         }
 
         //
         // Accept new connections
         //
         for (const ListenSocket &hListenSocket : vhListenSocket) {
             if (hListenSocket.socket != INVALID_SOCKET &&
                 FD_ISSET(hListenSocket.socket, &fdsetRecv)) {
                 AcceptConnection(hListenSocket);
             }
         }
 
         //
         // Service each socket
         //
         std::vector<CNode *> vNodesCopy;
         {
             LOCK(cs_vNodes);
             vNodesCopy = vNodes;
             for (CNode *pnode : vNodesCopy) {
                 pnode->AddRef();
             }
         }
         for (CNode *pnode : vNodesCopy) {
             if (interruptNet) {
                 return;
             }
 
             //
             // Receive
             //
             bool recvSet = false;
             bool sendSet = false;
             bool errorSet = false;
             {
                 LOCK(pnode->cs_hSocket);
                 if (pnode->hSocket == INVALID_SOCKET) {
                     continue;
                 }
                 recvSet = FD_ISSET(pnode->hSocket, &fdsetRecv);
                 sendSet = FD_ISSET(pnode->hSocket, &fdsetSend);
                 errorSet = FD_ISSET(pnode->hSocket, &fdsetError);
             }
             if (recvSet || errorSet) {
                 // typical socket buffer is 8K-64K
                 char pchBuf[0x10000];
                 int nBytes = 0;
                 {
                     LOCK(pnode->cs_hSocket);
                     if (pnode->hSocket == INVALID_SOCKET) {
                         continue;
                     }
                     nBytes = recv(pnode->hSocket, pchBuf, sizeof(pchBuf),
                                   MSG_DONTWAIT);
                 }
                 if (nBytes > 0) {
                     bool notify = false;
                     if (!pnode->ReceiveMsgBytes(*config, pchBuf, nBytes,
                                                 notify)) {
                         pnode->CloseSocketDisconnect();
                     }
                     RecordBytesRecv(nBytes);
                     if (notify) {
                         size_t nSizeAdded = 0;
                         auto it(pnode->vRecvMsg.begin());
                         for (; it != pnode->vRecvMsg.end(); ++it) {
                             if (!it->complete()) {
                                 break;
                             }
                             nSizeAdded +=
                                 it->vRecv.size() + CMessageHeader::HEADER_SIZE;
                         }
                         {
                             LOCK(pnode->cs_vProcessMsg);
                             pnode->vProcessMsg.splice(
                                 pnode->vProcessMsg.end(), pnode->vRecvMsg,
                                 pnode->vRecvMsg.begin(), it);
                             pnode->nProcessQueueSize += nSizeAdded;
                             pnode->fPauseRecv =
                                 pnode->nProcessQueueSize > nReceiveFloodSize;
                         }
                         WakeMessageHandler();
                     }
                 } else if (nBytes == 0) {
                     // socket closed gracefully
                     if (!pnode->fDisconnect) {
                         LogPrint(BCLog::NET, "socket closed\n");
                     }
                     pnode->CloseSocketDisconnect();
                 } else if (nBytes < 0) {
                     // error
                     int nErr = WSAGetLastError();
                     if (nErr != WSAEWOULDBLOCK && nErr != WSAEMSGSIZE &&
                         nErr != WSAEINTR && nErr != WSAEINPROGRESS) {
                         if (!pnode->fDisconnect) {
                             LogPrintf("socket recv error %s\n",
                                       NetworkErrorString(nErr));
                         }
                         pnode->CloseSocketDisconnect();
                     }
                 }
             }
 
             //
             // Send
             //
             if (sendSet) {
                 LOCK(pnode->cs_vSend);
                 size_t nBytes = SocketSendData(pnode);
                 if (nBytes) {
                     RecordBytesSent(nBytes);
                 }
             }
 
             //
             // Inactivity checking
             //
             int64_t nTime = GetSystemTimeInSeconds();
             if (nTime - pnode->nTimeConnected > 60) {
                 if (pnode->nLastRecv == 0 || pnode->nLastSend == 0) {
                     LogPrint(BCLog::NET, "socket no message in first 60 "
                                          "seconds, %d %d from %d\n",
                              pnode->nLastRecv != 0, pnode->nLastSend != 0,
                              pnode->id);
                     pnode->fDisconnect = true;
                 } else if (nTime - pnode->nLastSend > TIMEOUT_INTERVAL) {
                     LogPrintf("socket sending timeout: %is\n",
                               nTime - pnode->nLastSend);
                     pnode->fDisconnect = true;
                 } else if (nTime - pnode->nLastRecv >
                            (pnode->nVersion > BIP0031_VERSION ? TIMEOUT_INTERVAL
                                                               : 90 * 60)) {
                     LogPrintf("socket receive timeout: %is\n",
                               nTime - pnode->nLastRecv);
                     pnode->fDisconnect = true;
                 } else if (pnode->nPingNonceSent &&
                            pnode->nPingUsecStart + TIMEOUT_INTERVAL * 1000000 <
                                GetTimeMicros()) {
                     LogPrintf("ping timeout: %fs\n",
                               0.000001 *
                                   (GetTimeMicros() - pnode->nPingUsecStart));
                     pnode->fDisconnect = true;
                 } else if (!pnode->fSuccessfullyConnected) {
                     LogPrintf("version handshake timeout from %d\n", pnode->id);
                     pnode->fDisconnect = true;
                 }
             }
         }
         {
             LOCK(cs_vNodes);
             for (CNode *pnode : vNodesCopy) {
                 pnode->Release();
             }
         }
     }
 }
 
 void CConnman::WakeMessageHandler() {
     {
         std::lock_guard<std::mutex> lock(mutexMsgProc);
         fMsgProcWake = true;
     }
     condMsgProc.notify_one();
 }
 
 #ifdef USE_UPNP
 void ThreadMapPort() {
     std::string port = strprintf("%u", GetListenPort());
     const char *multicastif = 0;
     const char *minissdpdpath = 0;
     struct UPNPDev *devlist = 0;
     char lanaddr[64];
 
 #ifndef UPNPDISCOVER_SUCCESS
     /* miniupnpc 1.5 */
     devlist = upnpDiscover(2000, multicastif, minissdpdpath, 0);
 #elif MINIUPNPC_API_VERSION < 14
     /* miniupnpc 1.6 */
     int error = 0;
     devlist = upnpDiscover(2000, multicastif, minissdpdpath, 0, 0, &error);
 #else
     /* miniupnpc 1.9.20150730 */
     int error = 0;
     devlist = upnpDiscover(2000, multicastif, minissdpdpath, 0, 0, 2, &error);
 #endif
 
     struct UPNPUrls urls;
     struct IGDdatas data;
     int r;
 
     r = UPNP_GetValidIGD(devlist, &urls, &data, lanaddr, sizeof(lanaddr));
     if (r == 1) {
         if (fDiscover) {
             char externalIPAddress[40];
             r = UPNP_GetExternalIPAddress(
                 urls.controlURL, data.first.servicetype, externalIPAddress);
             if (r != UPNPCOMMAND_SUCCESS) {
                 LogPrintf("UPnP: GetExternalIPAddress() returned %d\n", r);
             } else {
                 if (externalIPAddress[0]) {
                     CNetAddr resolved;
                     if (LookupHost(externalIPAddress, resolved, false)) {
                         LogPrintf("UPnP: ExternalIPAddress = %s\n",
                                   resolved.ToString().c_str());
                         AddLocal(resolved, LOCAL_UPNP);
                     }
                 } else {
                     LogPrintf("UPnP: GetExternalIPAddress failed.\n");
                 }
             }
         }
 
         std::string strDesc = "Bitcoin " + FormatFullVersion();
 
         try {
             while (true) {
 #ifndef UPNPDISCOVER_SUCCESS
                 /* miniupnpc 1.5 */
                 r = UPNP_AddPortMapping(urls.controlURL, data.first.servicetype,
                                         port.c_str(), port.c_str(), lanaddr,
                                         strDesc.c_str(), "TCP", 0);
 #else
                 /* miniupnpc 1.6 */
                 r = UPNP_AddPortMapping(urls.controlURL, data.first.servicetype,
                                         port.c_str(), port.c_str(), lanaddr,
                                         strDesc.c_str(), "TCP", 0, "0");
 #endif
 
                 if (r != UPNPCOMMAND_SUCCESS) {
                     LogPrintf(
                         "AddPortMapping(%s, %s, %s) failed with code %d (%s)\n",
                         port, port, lanaddr, r, strupnperror(r));
                 } else {
                     LogPrintf("UPnP Port Mapping successful.\n");
                 }
 
                 // Refresh every 20 minutes
                 MilliSleep(20 * 60 * 1000);
             }
         } catch (const boost::thread_interrupted &) {
             r = UPNP_DeletePortMapping(urls.controlURL, data.first.servicetype,
                                        port.c_str(), "TCP", 0);
             LogPrintf("UPNP_DeletePortMapping() returned: %d\n", r);
             freeUPNPDevlist(devlist);
             devlist = 0;
             FreeUPNPUrls(&urls);
             throw;
         }
     } else {
         LogPrintf("No valid UPnP IGDs found\n");
         freeUPNPDevlist(devlist);
         devlist = 0;
         if (r != 0) {
             FreeUPNPUrls(&urls);
         }
     }
 }
 
 void MapPort(bool fUseUPnP) {
     static boost::thread *upnp_thread = nullptr;
 
     if (fUseUPnP) {
         if (upnp_thread) {
             upnp_thread->interrupt();
             upnp_thread->join();
             delete upnp_thread;
         }
         upnp_thread = new boost::thread(
             boost::bind(&TraceThread<void (*)()>, "upnp", &ThreadMapPort));
     } else if (upnp_thread) {
         upnp_thread->interrupt();
         upnp_thread->join();
         delete upnp_thread;
         upnp_thread = nullptr;
     }
 }
 
 #else
 void MapPort(bool) {
     // Intentionally left blank.
 }
 #endif
 
 static std::string GetDNSHost(const CDNSSeedData &data,
                               ServiceFlags *requiredServiceBits) {
     // use default host for non-filter-capable seeds or if we use the default
     // service bits (NODE_NETWORK)
     if (!data.supportsServiceBitsFiltering ||
         *requiredServiceBits == NODE_NETWORK) {
         *requiredServiceBits = NODE_NETWORK;
         return data.host;
     }
 
     // See chainparams.cpp, most dnsseeds only support one or two possible
     // servicebits hostnames
     return strprintf("x%x.%s", *requiredServiceBits, data.host);
 }
 
 void CConnman::ThreadDNSAddressSeed() {
     // goal: only query DNS seeds if address need is acute.
     // Avoiding DNS seeds when we don't need them improves user privacy by
     // creating fewer identifying DNS requests, reduces trust by giving seeds
     // less influence on the network topology, and reduces traffic to the seeds.
     if ((addrman.size() > 0) &&
         (!gArgs.GetBoolArg("-forcednsseed", DEFAULT_FORCEDNSSEED))) {
         if (!interruptNet.sleep_for(std::chrono::seconds(11))) {
             return;
         }
 
         LOCK(cs_vNodes);
         int nRelevant = 0;
         for (auto pnode : vNodes) {
             nRelevant +=
                 pnode->fSuccessfullyConnected &&
                 ((pnode->nServices & nRelevantServices) == nRelevantServices);
         }
         if (nRelevant >= 2) {
             LogPrintf("P2P peers available. Skipped DNS seeding.\n");
             return;
         }
     }
 
     const std::vector<CDNSSeedData> &vSeeds =
         config->GetChainParams().DNSSeeds();
     int found = 0;
 
     LogPrintf("Loading addresses from DNS seeds (could take a while)\n");
 
     for (const CDNSSeedData &seed : vSeeds) {
         if (HaveNameProxy()) {
             AddOneShot(seed.host);
         } else {
             std::vector<CNetAddr> vIPs;
             std::vector<CAddress> vAdd;
             ServiceFlags requiredServiceBits = nRelevantServices;
             if (LookupHost(GetDNSHost(seed, &requiredServiceBits).c_str(), vIPs,
                            0, true)) {
                 for (const CNetAddr &ip : vIPs) {
                     int nOneDay = 24 * 3600;
                     CAddress addr = CAddress(
                         CService(ip, config->GetChainParams().GetDefaultPort()),
                         requiredServiceBits);
                     // Use a random age between 3 and 7 days old.
                     addr.nTime = GetTime() - 3 * nOneDay - GetRand(4 * nOneDay);
                     vAdd.push_back(addr);
                     found++;
                 }
             }
             // TODO: The seed name resolve may fail, yielding an IP of [::],
             // which results in addrman assigning the same source to results
             // from different seeds. This should switch to a hard-coded stable
             // dummy IP for each seed name, so that the resolve is not required
             // at all.
             if (!vIPs.empty()) {
                 CService seedSource;
                 Lookup(seed.name.c_str(), seedSource, 0, true);
                 addrman.Add(vAdd, seedSource);
             }
         }
     }
 
     LogPrintf("%d addresses found from DNS seeds\n", found);
 }
 
 void CConnman::DumpAddresses() {
     int64_t nStart = GetTimeMillis();
 
     CAddrDB adb(config->GetChainParams());
     adb.Write(addrman);
 
     LogPrint(BCLog::NET, "Flushed %d addresses to peers.dat  %dms\n",
              addrman.size(), GetTimeMillis() - nStart);
 }
 
 void CConnman::DumpData() {
     DumpAddresses();
     DumpBanlist();
 }
 
 void CConnman::ProcessOneShot() {
     std::string strDest;
     {
         LOCK(cs_vOneShots);
         if (vOneShots.empty()) {
             return;
         }
         strDest = vOneShots.front();
         vOneShots.pop_front();
     }
     CAddress addr;
     CSemaphoreGrant grant(*semOutbound, true);
     if (grant) {
         if (!OpenNetworkConnection(addr, false, &grant, strDest.c_str(),
                                    true)) {
             AddOneShot(strDest);
         }
     }
 }
 
 void CConnman::ThreadOpenConnections() {
     // Connect to specific addresses
     if (gArgs.IsArgSet("-connect") && gArgs.GetArgs("-connect").size() > 0) {
         for (int64_t nLoop = 0;; nLoop++) {
             ProcessOneShot();
             for (const std::string &strAddr : gArgs.GetArgs("-connect")) {
                 CAddress addr(CService(), NODE_NONE);
                 OpenNetworkConnection(addr, false, nullptr, strAddr.c_str());
                 for (int i = 0; i < 10 && i < nLoop; i++) {
                     if (!interruptNet.sleep_for(
                             std::chrono::milliseconds(500))) {
                         return;
                     }
                 }
             }
             if (!interruptNet.sleep_for(std::chrono::milliseconds(500))) {
                 return;
             }
         }
     }
 
     // Initiate network connections
     int64_t nStart = GetTime();
 
     // Minimum time before next feeler connection (in microseconds).
     int64_t nNextFeeler =
         PoissonNextSend(nStart * 1000 * 1000, FEELER_INTERVAL);
     while (!interruptNet) {
         ProcessOneShot();
 
         if (!interruptNet.sleep_for(std::chrono::milliseconds(500))) {
             return;
         }
 
         CSemaphoreGrant grant(*semOutbound);
         if (interruptNet) {
             return;
         }
 
         // Add seed nodes if DNS seeds are all down (an infrastructure attack?).
         if (addrman.size() == 0 && (GetTime() - nStart > 60)) {
             static bool done = false;
             if (!done) {
                 LogPrintf("Adding fixed seed nodes as DNS doesn't seem to be "
                           "available.\n");
                 CNetAddr local;
                 LookupHost("127.0.0.1", local, false);
                 addrman.Add(convertSeed6(config->GetChainParams().FixedSeeds()),
                             local);
                 done = true;
             }
         }
 
         //
         // Choose an address to connect to based on most recently seen
         //
         CAddress addrConnect;
 
         // Only connect out to one peer per network group (/16 for IPv4). Do
         // this here so we don't have to critsect vNodes inside mapAddresses
         // critsect.
         int nOutbound = 0;
         std::set<std::vector<uint8_t>> setConnected;
         {
             LOCK(cs_vNodes);
             for (CNode *pnode : vNodes) {
                 if (!pnode->fInbound && !pnode->fAddnode) {
                     // Netgroups for inbound and addnode peers are not excluded
                     // because our goal here is to not use multiple of our
                     // limited outbound slots on a single netgroup but inbound
                     // and addnode peers do not use our outbound slots. Inbound
                     // peers also have the added issue that they're attacker
                     // controlled and could be used to prevent us from
                     // connecting to particular hosts if we used them here.
                     setConnected.insert(pnode->addr.GetGroup());
                     nOutbound++;
                 }
             }
         }
 
         // Feeler Connections
         //
         // Design goals:
         //  * Increase the number of connectable addresses in the tried table.
         //
         // Method:
         //  * Choose a random address from new and attempt to connect to it if
         //  we can connect successfully it is added to tried.
         //  * Start attempting feeler connections only after node finishes
         //  making outbound connections.
         //  * Only make a feeler connection once every few minutes.
         //
         bool fFeeler = false;
         if (nOutbound >= nMaxOutbound) {
             // The current time right now (in microseconds).
             int64_t nTime = GetTimeMicros();
             if (nTime > nNextFeeler) {
                 nNextFeeler = PoissonNextSend(nTime, FEELER_INTERVAL);
                 fFeeler = true;
             } else {
                 continue;
             }
         }
 
         int64_t nANow = GetAdjustedTime();
         int nTries = 0;
         while (!interruptNet) {
             CAddrInfo addr = addrman.Select(fFeeler);
 
             // if we selected an invalid address, restart
             if (!addr.IsValid() || setConnected.count(addr.GetGroup()) ||
                 IsLocal(addr)) {
                 break;
             }
 
             // If we didn't find an appropriate destination after trying 100
             // addresses fetched from addrman, stop this loop, and let the outer
             // loop run again (which sleeps, adds seed nodes, recalculates
             // already-connected network ranges, ...) before trying new addrman
             // addresses.
             nTries++;
             if (nTries > 100) {
                 break;
             }
 
             if (IsLimited(addr)) {
                 continue;
             }
 
             // only connect to full nodes
             if ((addr.nServices & REQUIRED_SERVICES) != REQUIRED_SERVICES) {
                 continue;
             }
 
             // only consider very recently tried nodes after 30 failed attempts
             if (nANow - addr.nLastTry < 600 && nTries < 30) {
                 continue;
             }
 
             // only consider nodes missing relevant services after 40 failed
             // attempts and only if less than half the outbound are up.
             if ((addr.nServices & nRelevantServices) != nRelevantServices &&
                 (nTries < 40 || nOutbound >= (nMaxOutbound >> 1))) {
                 continue;
             }
 
             // do not allow non-default ports, unless after 50 invalid addresses
             // selected already.
             if (addr.GetPort() != config->GetChainParams().GetDefaultPort() &&
                 nTries < 50) {
                 continue;
             }
 
             addrConnect = addr;
             break;
         }
 
         if (addrConnect.IsValid()) {
 
             if (fFeeler) {
                 // Add small amount of random noise before connection to avoid
                 // synchronization.
                 int randsleep = GetRandInt(FEELER_SLEEP_WINDOW * 1000);
                 if (!interruptNet.sleep_for(
                         std::chrono::milliseconds(randsleep))) {
                     return;
                 }
                 LogPrint(BCLog::NET, "Making feeler connection to %s\n",
                          addrConnect.ToString());
             }
 
             OpenNetworkConnection(addrConnect,
                                   (int)setConnected.size() >=
                                       std::min(nMaxConnections - 1, 2),
                                   &grant, nullptr, false, fFeeler);
         }
     }
 }
 
 std::vector<AddedNodeInfo> CConnman::GetAddedNodeInfo() {
     std::vector<AddedNodeInfo> ret;
 
     std::list<std::string> lAddresses(0);
     {
         LOCK(cs_vAddedNodes);
         ret.reserve(vAddedNodes.size());
         for (const std::string &strAddNode : vAddedNodes) {
             lAddresses.push_back(strAddNode);
         }
     }
 
     // Build a map of all already connected addresses (by IP:port and by name)
     // to inbound/outbound and resolved CService
     std::map<CService, bool> mapConnected;
     std::map<std::string, std::pair<bool, CService>> mapConnectedByName;
     {
         LOCK(cs_vNodes);
         for (const CNode *pnode : vNodes) {
             if (pnode->addr.IsValid()) {
                 mapConnected[pnode->addr] = pnode->fInbound;
             }
             std::string addrName = pnode->GetAddrName();
             if (!addrName.empty()) {
                 mapConnectedByName[std::move(addrName)] =
                     std::make_pair(pnode->fInbound,
                                    static_cast<const CService &>(pnode->addr));
             }
         }
     }
 
     for (const std::string &strAddNode : lAddresses) {
         CService service(LookupNumeric(
             strAddNode.c_str(), config->GetChainParams().GetDefaultPort()));
         if (service.IsValid()) {
             // strAddNode is an IP:port
             auto it = mapConnected.find(service);
             if (it != mapConnected.end()) {
                 ret.push_back(
                     AddedNodeInfo{strAddNode, service, true, it->second});
             } else {
                 ret.push_back(
                     AddedNodeInfo{strAddNode, CService(), false, false});
             }
         } else {
             // strAddNode is a name
             auto it = mapConnectedByName.find(strAddNode);
             if (it != mapConnectedByName.end()) {
                 ret.push_back(AddedNodeInfo{strAddNode, it->second.second, true,
                                             it->second.first});
             } else {
                 ret.push_back(
                     AddedNodeInfo{strAddNode, CService(), false, false});
             }
         }
     }
 
     return ret;
 }
 
 void CConnman::ThreadOpenAddedConnections() {
     {
         LOCK(cs_vAddedNodes);
         if (gArgs.IsArgSet("-addnode")) {
             vAddedNodes = gArgs.GetArgs("-addnode");
         }
     }
 
     while (true) {
         CSemaphoreGrant grant(*semAddnode);
         std::vector<AddedNodeInfo> vInfo = GetAddedNodeInfo();
         bool tried = false;
         for (const AddedNodeInfo &info : vInfo) {
             if (!info.fConnected) {
                 if (!grant.TryAcquire()) {
                     // If we've used up our semaphore and need a new one, lets
                     // not wait here since while we are waiting the
                     // addednodeinfo state might change.
                     break;
                 }
                 // If strAddedNode is an IP/port, decode it immediately, so
                 // OpenNetworkConnection can detect existing connections to that
                 // IP/port.
                 tried = true;
                 CService service(
                     LookupNumeric(info.strAddedNode.c_str(),
                                   config->GetChainParams().GetDefaultPort()));
                 OpenNetworkConnection(CAddress(service, NODE_NONE), false,
                                       &grant, info.strAddedNode.c_str(), false,
                                       false, true);
                 if (!interruptNet.sleep_for(std::chrono::milliseconds(500))) {
                     return;
                 }
             }
         }
         // Retry every 60 seconds if a connection was attempted, otherwise two
         // seconds.
         if (!interruptNet.sleep_for(std::chrono::seconds(tried ? 60 : 2))) {
             return;
         }
     }
 }
 
 // If successful, this moves the passed grant to the constructed node.
 bool CConnman::OpenNetworkConnection(const CAddress &addrConnect,
                                      bool fCountFailure,
                                      CSemaphoreGrant *grantOutbound,
                                      const char *pszDest, bool fOneShot,
                                      bool fFeeler, bool fAddnode) {
     //
     // Initiate outbound network connection
     //
     if (interruptNet) {
         return false;
     }
     if (!fNetworkActive) {
         return false;
     }
     if (!pszDest) {
         if (IsLocal(addrConnect) || FindNode((CNetAddr)addrConnect) ||
             IsBanned(addrConnect) || FindNode(addrConnect.ToStringIPPort())) {
             return false;
         }
     } else if (FindNode(std::string(pszDest))) {
         return false;
     }
 
     CNode *pnode = ConnectNode(addrConnect, pszDest, fCountFailure);
 
     if (!pnode) {
         return false;
     }
     if (grantOutbound) {
         grantOutbound->MoveTo(pnode->grantOutbound);
     }
     if (fOneShot) {
         pnode->fOneShot = true;
     }
     if (fFeeler) {
         pnode->fFeeler = true;
     }
     if (fAddnode) {
         pnode->fAddnode = true;
     }
 
     GetNodeSignals().InitializeNode(*config, pnode, *this);
     {
         LOCK(cs_vNodes);
         vNodes.push_back(pnode);
     }
 
     return true;
 }
 
 void CConnman::ThreadMessageHandler() {
     while (!flagInterruptMsgProc) {
         std::vector<CNode *> vNodesCopy;
         {
             LOCK(cs_vNodes);
             vNodesCopy = vNodes;
             for (CNode *pnode : vNodesCopy) {
                 pnode->AddRef();
             }
         }
 
         bool fMoreWork = false;
 
         for (CNode *pnode : vNodesCopy) {
             if (pnode->fDisconnect) {
                 continue;
             }
 
             // Receive messages
             bool fMoreNodeWork = GetNodeSignals().ProcessMessages(
                 *config, pnode, *this, flagInterruptMsgProc);
             fMoreWork |= (fMoreNodeWork && !pnode->fPauseSend);
             if (flagInterruptMsgProc) {
                 return;
             }
 
             // Send messages
             {
                 LOCK(pnode->cs_sendProcessing);
                 GetNodeSignals().SendMessages(*config, pnode, *this,
                                               flagInterruptMsgProc);
             }
             if (flagInterruptMsgProc) {
                 return;
             }
         }
 
         {
             LOCK(cs_vNodes);
             for (CNode *pnode : vNodesCopy) {
                 pnode->Release();
             }
         }
 
         std::unique_lock<std::mutex> lock(mutexMsgProc);
         if (!fMoreWork) {
             condMsgProc.wait_until(lock,
                                    std::chrono::steady_clock::now() +
                                        std::chrono::milliseconds(100),
                                    [this] { return fMsgProcWake; });
         }
         fMsgProcWake = false;
     }
 }
 
 bool CConnman::BindListenPort(const CService &addrBind, std::string &strError,
                               bool fWhitelisted) {
     strError = "";
     int nOne = 1;
 
     // Create socket for listening for incoming connections
     struct sockaddr_storage sockaddr;
     socklen_t len = sizeof(sockaddr);
     if (!addrBind.GetSockAddr((struct sockaddr *)&sockaddr, &len)) {
         strError = strprintf("Error: Bind address family for %s not supported",
                              addrBind.ToString());
         LogPrintf("%s\n", strError);
         return false;
     }
 
     SOCKET hListenSocket = socket(((struct sockaddr *)&sockaddr)->sa_family,
                                   SOCK_STREAM, IPPROTO_TCP);
     if (hListenSocket == INVALID_SOCKET) {
         strError = strprintf("Error: Couldn't open socket for incoming "
                              "connections (socket returned error %s)",
                              NetworkErrorString(WSAGetLastError()));
         LogPrintf("%s\n", strError);
         return false;
     }
     if (!IsSelectableSocket(hListenSocket)) {
         strError = "Error: Couldn't create a listenable socket for incoming "
                    "connections";
         LogPrintf("%s\n", strError);
         return false;
     }
 
 #ifndef WIN32
 #ifdef SO_NOSIGPIPE
     // Different way of disabling SIGPIPE on BSD
     setsockopt(hListenSocket, SOL_SOCKET, SO_NOSIGPIPE, (void *)&nOne,
                sizeof(int));
 #endif
     // Allow binding if the port is still in TIME_WAIT state after
     // the program was closed and restarted.
     setsockopt(hListenSocket, SOL_SOCKET, SO_REUSEADDR, (void *)&nOne,
                sizeof(int));
     // Disable Nagle's algorithm
     setsockopt(hListenSocket, IPPROTO_TCP, TCP_NODELAY, (void *)&nOne,
                sizeof(int));
 #else
     setsockopt(hListenSocket, SOL_SOCKET, SO_REUSEADDR, (const char *)&nOne,
                sizeof(int));
     setsockopt(hListenSocket, IPPROTO_TCP, TCP_NODELAY, (const char *)&nOne,
                sizeof(int));
 #endif
 
     // Set to non-blocking, incoming connections will also inherit this
     if (!SetSocketNonBlocking(hListenSocket, true)) {
         strError = strprintf("BindListenPort: Setting listening socket to "
                              "non-blocking failed, error %s\n",
                              NetworkErrorString(WSAGetLastError()));
         LogPrintf("%s\n", strError);
         return false;
     }
 
     // Some systems don't have IPV6_V6ONLY but are always v6only; others do have
     // the option and enable it by default or not. Try to enable it, if
     // possible.
     if (addrBind.IsIPv6()) {
 #ifdef IPV6_V6ONLY
 #ifdef WIN32
         setsockopt(hListenSocket, IPPROTO_IPV6, IPV6_V6ONLY,
                    (const char *)&nOne, sizeof(int));
 #else
         setsockopt(hListenSocket, IPPROTO_IPV6, IPV6_V6ONLY, (void *)&nOne,
                    sizeof(int));
 #endif
 #endif
 #ifdef WIN32
         int nProtLevel = PROTECTION_LEVEL_UNRESTRICTED;
         setsockopt(hListenSocket, IPPROTO_IPV6, IPV6_PROTECTION_LEVEL,
                    (const char *)&nProtLevel, sizeof(int));
 #endif
     }
 
     if (::bind(hListenSocket, (struct sockaddr *)&sockaddr, len) ==
         SOCKET_ERROR) {
         int nErr = WSAGetLastError();
         if (nErr == WSAEADDRINUSE) {
             strError = strprintf(_("Unable to bind to %s on this computer. %s "
                                    "is probably already running."),
                                  addrBind.ToString(), _(PACKAGE_NAME));
         } else {
             strError = strprintf(_("Unable to bind to %s on this computer "
                                    "(bind returned error %s)"),
                                  addrBind.ToString(), NetworkErrorString(nErr));
         }
         LogPrintf("%s\n", strError);
         CloseSocket(hListenSocket);
         return false;
     }
     LogPrintf("Bound to %s\n", addrBind.ToString());
 
     // Listen for incoming connections
     if (listen(hListenSocket, SOMAXCONN) == SOCKET_ERROR) {
         strError = strprintf(_("Error: Listening for incoming connections "
                                "failed (listen returned error %s)"),
                              NetworkErrorString(WSAGetLastError()));
         LogPrintf("%s\n", strError);
         CloseSocket(hListenSocket);
         return false;
     }
 
     vhListenSocket.push_back(ListenSocket(hListenSocket, fWhitelisted));
 
     if (addrBind.IsRoutable() && fDiscover && !fWhitelisted) {
         AddLocal(addrBind, LOCAL_BIND);
     }
 
     return true;
 }
 
 void Discover(boost::thread_group &threadGroup) {
     if (!fDiscover) {
         return;
     }
 
 #ifdef WIN32
     // Get local host IP
     char pszHostName[256] = "";
     if (gethostname(pszHostName, sizeof(pszHostName)) != SOCKET_ERROR) {
         std::vector<CNetAddr> vaddr;
         if (LookupHost(pszHostName, vaddr, 0, true)) {
             for (const CNetAddr &addr : vaddr) {
                 if (AddLocal(addr, LOCAL_IF)) {
                     LogPrintf("%s: %s - %s\n", __func__, pszHostName,
                               addr.ToString());
                 }
             }
         }
     }
 #else
     // Get local host ip
     struct ifaddrs *myaddrs;
     if (getifaddrs(&myaddrs) == 0) {
         for (struct ifaddrs *ifa = myaddrs; ifa != nullptr;
              ifa = ifa->ifa_next) {
             if (ifa->ifa_addr == nullptr || (ifa->ifa_flags & IFF_UP) == 0 ||
                 strcmp(ifa->ifa_name, "lo") == 0 ||
                 strcmp(ifa->ifa_name, "lo0") == 0) {
                 continue;
             }
             if (ifa->ifa_addr->sa_family == AF_INET) {
                 struct sockaddr_in *s4 = (struct sockaddr_in *)(ifa->ifa_addr);
                 CNetAddr addr(s4->sin_addr);
                 if (AddLocal(addr, LOCAL_IF)) {
                     LogPrintf("%s: IPv4 %s: %s\n", __func__, ifa->ifa_name,
                               addr.ToString());
                 }
             } else if (ifa->ifa_addr->sa_family == AF_INET6) {
                 struct sockaddr_in6 *s6 =
                     (struct sockaddr_in6 *)(ifa->ifa_addr);
                 CNetAddr addr(s6->sin6_addr);
                 if (AddLocal(addr, LOCAL_IF)) {
                     LogPrintf("%s: IPv6 %s: %s\n", __func__, ifa->ifa_name,
                               addr.ToString());
                 }
             }
         }
         freeifaddrs(myaddrs);
     }
 #endif
 }
 
 void CConnman::SetNetworkActive(bool active) {
     LogPrint(BCLog::NET, "SetNetworkActive: %s\n", active);
 
     if (!active) {
         fNetworkActive = false;
 
         LOCK(cs_vNodes);
         // Close sockets to all nodes
         for (CNode *pnode : vNodes) {
             pnode->CloseSocketDisconnect();
         }
     } else {
         fNetworkActive = true;
     }
 
     uiInterface.NotifyNetworkActiveChanged(fNetworkActive);
 }
 
 CConnman::CConnman(const Config &configIn, uint64_t nSeed0In, uint64_t nSeed1In)
     : config(&configIn), nSeed0(nSeed0In), nSeed1(nSeed1In) {
     fNetworkActive = true;
     setBannedIsDirty = false;
     fAddressesInitialized = false;
     nLastNodeId = 0;
     nSendBufferMaxSize = 0;
     nReceiveFloodSize = 0;
     semOutbound = nullptr;
     semAddnode = nullptr;
     nMaxConnections = 0;
     nMaxOutbound = 0;
     nMaxAddnode = 0;
     nBestHeight = 0;
     clientInterface = nullptr;
     flagInterruptMsgProc = false;
 }
 
 NodeId CConnman::GetNewNodeId() {
     return nLastNodeId.fetch_add(1, std::memory_order_relaxed);
 }
 
 bool CConnman::Start(CScheduler &scheduler, std::string &strNodeError,
                      Options connOptions) {
     nTotalBytesRecv = 0;
     nTotalBytesSent = 0;
     nMaxOutboundTotalBytesSentInCycle = 0;
     nMaxOutboundCycleStartTime = 0;
 
     nRelevantServices = connOptions.nRelevantServices;
     nLocalServices = connOptions.nLocalServices;
     nMaxConnections = connOptions.nMaxConnections;
     nMaxOutbound = std::min((connOptions.nMaxOutbound), nMaxConnections);
     nMaxAddnode = connOptions.nMaxAddnode;
     nMaxFeeler = connOptions.nMaxFeeler;
 
     nSendBufferMaxSize = connOptions.nSendBufferMaxSize;
     nReceiveFloodSize = connOptions.nReceiveFloodSize;
 
     nMaxOutboundLimit = connOptions.nMaxOutboundLimit;
     nMaxOutboundTimeframe = connOptions.nMaxOutboundTimeframe;
 
     SetBestHeight(connOptions.nBestHeight);
 
     clientInterface = connOptions.uiInterface;
     if (clientInterface) {
         clientInterface->InitMessage(_("Loading addresses..."));
     }
     // Load addresses from peers.dat
     int64_t nStart = GetTimeMillis();
     {
         CAddrDB adb(config->GetChainParams());
         if (adb.Read(addrman)) {
             LogPrintf("Loaded %i addresses from peers.dat  %dms\n",
                       addrman.size(), GetTimeMillis() - nStart);
         } else {
             // Addrman can be in an inconsistent state after failure, reset it
             addrman.Clear();
             LogPrintf("Invalid or missing peers.dat; recreating\n");
             DumpAddresses();
         }
     }
     if (clientInterface) {
         clientInterface->InitMessage(_("Loading banlist..."));
     }
     // Load addresses from banlist.dat
     nStart = GetTimeMillis();
     CBanDB bandb(config->GetChainParams());
     banmap_t banmap;
     if (bandb.Read(banmap)) {
         // thread save setter
         SetBanned(banmap);
         // no need to write down, just read data
         SetBannedSetDirty(false);
         // sweep out unused entries
         SweepBanned();
 
         LogPrint(BCLog::NET,
                  "Loaded %d banned node ips/subnets from banlist.dat  %dms\n",
                  banmap.size(), GetTimeMillis() - nStart);
     } else {
         LogPrintf("Invalid or missing banlist.dat; recreating\n");
         // force write
         SetBannedSetDirty(true);
         DumpBanlist();
     }
 
     uiInterface.InitMessage(_("Starting network threads..."));
 
     fAddressesInitialized = true;
 
     if (semOutbound == nullptr) {
         // initialize semaphore
         semOutbound = new CSemaphore(
             std::min((nMaxOutbound + nMaxFeeler), nMaxConnections));
     }
     if (semAddnode == nullptr) {
         // initialize semaphore
         semAddnode = new CSemaphore(nMaxAddnode);
     }
 
     //
     // Start threads
     //
     InterruptSocks5(false);
     interruptNet.reset();
     flagInterruptMsgProc = false;
 
     {
         std::unique_lock<std::mutex> lock(mutexMsgProc);
         fMsgProcWake = false;
     }
 
     // Send and receive from sockets, accept connections
     threadSocketHandler = std::thread(
         &TraceThread<std::function<void()>>, "net",
         std::function<void()>(std::bind(&CConnman::ThreadSocketHandler, this)));
 
     if (!gArgs.GetBoolArg("-dnsseed", true)) {
         LogPrintf("DNS seeding disabled\n");
     } else {
         threadDNSAddressSeed =
             std::thread(&TraceThread<std::function<void()>>, "dnsseed",
                         std::function<void()>(
                             std::bind(&CConnman::ThreadDNSAddressSeed, this)));
     }
 
     // Initiate outbound connections from -addnode
     threadOpenAddedConnections =
         std::thread(&TraceThread<std::function<void()>>, "addcon",
                     std::function<void()>(std::bind(
                         &CConnman::ThreadOpenAddedConnections, this)));
 
     // Initiate outbound connections unless connect=0
     if (!gArgs.IsArgSet("-connect") || gArgs.GetArgs("-connect").size() != 1 ||
         gArgs.GetArgs("-connect")[0] != "0") {
         threadOpenConnections =
             std::thread(&TraceThread<std::function<void()>>, "opencon",
                         std::function<void()>(
                             std::bind(&CConnman::ThreadOpenConnections, this)));
     }
 
     // Process messages
     threadMessageHandler =
         std::thread(&TraceThread<std::function<void()>>, "msghand",
                     std::function<void()>(
                         std::bind(&CConnman::ThreadMessageHandler, this)));
 
     // Dump network addresses
     scheduler.scheduleEvery(std::bind(&CConnman::DumpData, this),
                             DUMP_ADDRESSES_INTERVAL * 1000);
 
     return true;
 }
 
 class CNetCleanup {
 public:
     CNetCleanup() {}
 
     ~CNetCleanup() {
 #ifdef WIN32
         // Shutdown Windows Sockets
         WSACleanup();
 #endif
     }
 } instance_of_cnetcleanup;
 
 void CConnman::Interrupt() {
     {
         std::lock_guard<std::mutex> lock(mutexMsgProc);
         flagInterruptMsgProc = true;
     }
     condMsgProc.notify_all();
 
     interruptNet();
     InterruptSocks5(true);
 
     if (semOutbound) {
         for (int i = 0; i < (nMaxOutbound + nMaxFeeler); i++) {
             semOutbound->post();
         }
     }
 
     if (semAddnode) {
         for (int i = 0; i < nMaxAddnode; i++) {
             semAddnode->post();
         }
     }
 }
 
 void CConnman::Stop() {
     if (threadMessageHandler.joinable()) {
         threadMessageHandler.join();
     }
     if (threadOpenConnections.joinable()) {
         threadOpenConnections.join();
     }
     if (threadOpenAddedConnections.joinable()) {
         threadOpenAddedConnections.join();
     }
     if (threadDNSAddressSeed.joinable()) {
         threadDNSAddressSeed.join();
     }
     if (threadSocketHandler.joinable()) {
         threadSocketHandler.join();
     }
 
     if (fAddressesInitialized) {
         DumpData();
         fAddressesInitialized = false;
     }
 
     // Close sockets
     for (CNode *pnode : vNodes) {
         pnode->CloseSocketDisconnect();
     }
     for (ListenSocket &hListenSocket : vhListenSocket) {
         if (hListenSocket.socket != INVALID_SOCKET) {
             if (!CloseSocket(hListenSocket.socket)) {
                 LogPrintf("CloseSocket(hListenSocket) failed with error %s\n",
                           NetworkErrorString(WSAGetLastError()));
             }
         }
     }
 
     // clean up some globals (to help leak detection)
     for (CNode *pnode : vNodes) {
         DeleteNode(pnode);
     }
     for (CNode *pnode : vNodesDisconnected) {
         DeleteNode(pnode);
     }
     vNodes.clear();
     vNodesDisconnected.clear();
     vhListenSocket.clear();
     delete semOutbound;
     semOutbound = nullptr;
     delete semAddnode;
     semAddnode = nullptr;
 }
 
 void CConnman::DeleteNode(CNode *pnode) {
     assert(pnode);
     bool fUpdateConnectionTime = false;
     GetNodeSignals().FinalizeNode(pnode->GetId(), fUpdateConnectionTime);
     if (fUpdateConnectionTime) {
         addrman.Connected(pnode->addr);
     }
     delete pnode;
 }
 
 CConnman::~CConnman() {
     Interrupt();
     Stop();
 }
 
 size_t CConnman::GetAddressCount() const {
     return addrman.size();
 }
 
 void CConnman::SetServices(const CService &addr, ServiceFlags nServices) {
     addrman.SetServices(addr, nServices);
 }
 
 void CConnman::MarkAddressGood(const CAddress &addr) {
     addrman.Good(addr);
 }
 
 void CConnman::AddNewAddress(const CAddress &addr, const CAddress &addrFrom,
                              int64_t nTimePenalty) {
     addrman.Add(addr, addrFrom, nTimePenalty);
 }
 
 void CConnman::AddNewAddresses(const std::vector<CAddress> &vAddr,
                                const CAddress &addrFrom, int64_t nTimePenalty) {
     addrman.Add(vAddr, addrFrom, nTimePenalty);
 }
 
 std::vector<CAddress> CConnman::GetAddresses() {
     return addrman.GetAddr();
 }
 
 bool CConnman::AddNode(const std::string &strNode) {
     LOCK(cs_vAddedNodes);
     for (std::vector<std::string>::const_iterator it = vAddedNodes.begin();
          it != vAddedNodes.end(); ++it) {
         if (strNode == *it) {
             return false;
         }
     }
 
     vAddedNodes.push_back(strNode);
     return true;
 }
 
 bool CConnman::RemoveAddedNode(const std::string &strNode) {
     LOCK(cs_vAddedNodes);
     for (std::vector<std::string>::iterator it = vAddedNodes.begin();
          it != vAddedNodes.end(); ++it) {
         if (strNode == *it) {
             vAddedNodes.erase(it);
             return true;
         }
     }
     return false;
 }
 
 size_t CConnman::GetNodeCount(NumConnections flags) {
     LOCK(cs_vNodes);
     // Shortcut if we want total
     if (flags == CConnman::CONNECTIONS_ALL) {
         return vNodes.size();
     }
 
     int nNum = 0;
     for (std::vector<CNode *>::const_iterator it = vNodes.begin();
          it != vNodes.end(); ++it) {
         if (flags & ((*it)->fInbound ? CONNECTIONS_IN : CONNECTIONS_OUT)) {
             nNum++;
         }
     }
 
     return nNum;
 }
 
 void CConnman::GetNodeStats(std::vector<CNodeStats> &vstats) {
     vstats.clear();
     LOCK(cs_vNodes);
     vstats.reserve(vNodes.size());
     for (CNode *pnode : vNodes) {
         vstats.emplace_back();
         pnode->copyStats(vstats.back());
     }
 }
 
 bool CConnman::DisconnectNode(const std::string &strNode) {
     LOCK(cs_vNodes);
     if (CNode *pnode = FindNode(strNode)) {
         pnode->fDisconnect = true;
         return true;
     }
     return false;
 }
 bool CConnman::DisconnectNode(NodeId id) {
     LOCK(cs_vNodes);
     for (CNode *pnode : vNodes) {
         if (id == pnode->id) {
             pnode->fDisconnect = true;
             return true;
         }
     }
     return false;
 }
 
 void CConnman::RecordBytesRecv(uint64_t bytes) {
     LOCK(cs_totalBytesRecv);
     nTotalBytesRecv += bytes;
 }
 
 void CConnman::RecordBytesSent(uint64_t bytes) {
     LOCK(cs_totalBytesSent);
     nTotalBytesSent += bytes;
 
     uint64_t now = GetTime();
     if (nMaxOutboundCycleStartTime + nMaxOutboundTimeframe < now) {
         // timeframe expired, reset cycle
         nMaxOutboundCycleStartTime = now;
         nMaxOutboundTotalBytesSentInCycle = 0;
     }
 
     // TODO, exclude whitebind peers
     nMaxOutboundTotalBytesSentInCycle += bytes;
 }
 
 void CConnman::SetMaxOutboundTarget(uint64_t limit) {
     LOCK(cs_totalBytesSent);
     nMaxOutboundLimit = limit;
 }
 
 uint64_t CConnman::GetMaxOutboundTarget() {
     LOCK(cs_totalBytesSent);
     return nMaxOutboundLimit;
 }
 
 uint64_t CConnman::GetMaxOutboundTimeframe() {
     LOCK(cs_totalBytesSent);
     return nMaxOutboundTimeframe;
 }
 
 uint64_t CConnman::GetMaxOutboundTimeLeftInCycle() {
     LOCK(cs_totalBytesSent);
     if (nMaxOutboundLimit == 0) {
         return 0;
     }
 
     if (nMaxOutboundCycleStartTime == 0) {
         return nMaxOutboundTimeframe;
     }
 
     uint64_t cycleEndTime = nMaxOutboundCycleStartTime + nMaxOutboundTimeframe;
     uint64_t now = GetTime();
     return (cycleEndTime < now) ? 0 : cycleEndTime - GetTime();
 }
 
 void CConnman::SetMaxOutboundTimeframe(uint64_t timeframe) {
     LOCK(cs_totalBytesSent);
     if (nMaxOutboundTimeframe != timeframe) {
         // reset measure-cycle in case of changing the timeframe.
         nMaxOutboundCycleStartTime = GetTime();
     }
     nMaxOutboundTimeframe = timeframe;
 }
 
 bool CConnman::OutboundTargetReached(bool historicalBlockServingLimit) {
     LOCK(cs_totalBytesSent);
     if (nMaxOutboundLimit == 0) {
         return false;
     }
 
     if (historicalBlockServingLimit) {
         // keep a large enough buffer to at least relay each block once.
         uint64_t timeLeftInCycle = GetMaxOutboundTimeLeftInCycle();
         uint64_t buffer = timeLeftInCycle / 600 * ONE_MEGABYTE;
         if (buffer >= nMaxOutboundLimit ||
             nMaxOutboundTotalBytesSentInCycle >= nMaxOutboundLimit - buffer) {
             return true;
         }
     } else if (nMaxOutboundTotalBytesSentInCycle >= nMaxOutboundLimit) {
         return true;
     }
 
     return false;
 }
 
 uint64_t CConnman::GetOutboundTargetBytesLeft() {
     LOCK(cs_totalBytesSent);
     if (nMaxOutboundLimit == 0) {
         return 0;
     }
 
     return (nMaxOutboundTotalBytesSentInCycle >= nMaxOutboundLimit)
                ? 0
                : nMaxOutboundLimit - nMaxOutboundTotalBytesSentInCycle;
 }
 
 uint64_t CConnman::GetTotalBytesRecv() {
     LOCK(cs_totalBytesRecv);
     return nTotalBytesRecv;
 }
 
 uint64_t CConnman::GetTotalBytesSent() {
     LOCK(cs_totalBytesSent);
     return nTotalBytesSent;
 }
 
 ServiceFlags CConnman::GetLocalServices() const {
     return nLocalServices;
 }
 
 void CConnman::SetBestHeight(int height) {
     nBestHeight.store(height, std::memory_order_release);
 }
 
 int CConnman::GetBestHeight() const {
     return nBestHeight.load(std::memory_order_acquire);
 }
 
 unsigned int CConnman::GetReceiveFloodSize() const {
     return nReceiveFloodSize;
 }
 unsigned int CConnman::GetSendBufferSize() const {
     return nSendBufferMaxSize;
 }
 
 CNode::CNode(NodeId idIn, ServiceFlags nLocalServicesIn,
              int nMyStartingHeightIn, SOCKET hSocketIn, const CAddress &addrIn,
              uint64_t nKeyedNetGroupIn, uint64_t nLocalHostNonceIn,
              const std::string &addrNameIn, bool fInboundIn)
     : nTimeConnected(GetSystemTimeInSeconds()), addr(addrIn),
       fInbound(fInboundIn), id(idIn), nKeyedNetGroup(nKeyedNetGroupIn),
       addrKnown(5000, 0.001), filterInventoryKnown(50000, 0.000001),
       nLocalHostNonce(nLocalHostNonceIn), nLocalServices(nLocalServicesIn),
       nMyStartingHeight(nMyStartingHeightIn), nSendVersion(0) {
     nServices = NODE_NONE;
     nServicesExpected = NODE_NONE;
     hSocket = hSocketIn;
     nRecvVersion = INIT_PROTO_VERSION;
     nLastSend = 0;
     nLastRecv = 0;
     nSendBytes = 0;
     nRecvBytes = 0;
     nTimeOffset = 0;
     addrName = addrNameIn == "" ? addr.ToStringIPPort() : addrNameIn;
     nVersion = 0;
     strSubVer = "";
     fWhitelisted = false;
     fOneShot = false;
     fAddnode = false;
     // set by version message
     fClient = false;
     fFeeler = false;
     fSuccessfullyConnected = false;
     fDisconnect = false;
     nRefCount = 0;
     nSendSize = 0;
     nSendOffset = 0;
     hashContinue = uint256();
     nStartingHeight = -1;
     filterInventoryKnown.reset();
     fSendMempool = false;
     fGetAddr = false;
     nNextLocalAddrSend = 0;
     nNextAddrSend = 0;
     nNextInvSend = 0;
     fRelayTxes = false;
     fSentAddr = false;
     pfilter = new CBloomFilter();
     timeLastMempoolReq = 0;
     nLastBlockTime = 0;
     nLastTXTime = 0;
     nPingNonceSent = 0;
     nPingUsecStart = 0;
     nPingUsecTime = 0;
     fPingQueued = false;
     nMinPingUsecTime = std::numeric_limits<int64_t>::max();
     minFeeFilter = Amount(0);
     lastSentFeeFilter = Amount(0);
     nextSendTimeFeeFilter = 0;
     fPauseRecv = false;
     fPauseSend = false;
     nProcessQueueSize = 0;
 
     for (const std::string &msg : getAllNetMessageTypes()) {
         mapRecvBytesPerMsgCmd[msg] = 0;
     }
     mapRecvBytesPerMsgCmd[NET_MESSAGE_COMMAND_OTHER] = 0;
 
     if (fLogIPs) {
         LogPrint(BCLog::NET, "Added connection to %s peer=%d\n", addrName, id);
     } else {
         LogPrint(BCLog::NET, "Added connection peer=%d\n", id);
     }
 }
 
 CNode::~CNode() {
     CloseSocket(hSocket);
 
     if (pfilter) {
         delete pfilter;
     }
 }
 
 void CNode::AskFor(const CInv &inv) {
     if (mapAskFor.size() > MAPASKFOR_MAX_SZ ||
         setAskFor.size() > SETASKFOR_MAX_SZ) {
         return;
     }
 
     // a peer may not have multiple non-responded queue positions for a single
     // inv item.
     if (!setAskFor.insert(inv.hash).second) {
         return;
     }
 
     // We're using mapAskFor as a priority queue, the key is the earliest time
     // the request can be sent.
     int64_t nRequestTime;
     limitedmap<uint256, int64_t>::const_iterator it =
         mapAlreadyAskedFor.find(inv.hash);
     if (it != mapAlreadyAskedFor.end()) {
         nRequestTime = it->second;
     } else {
         nRequestTime = 0;
     }
     LogPrint(BCLog::NET, "askfor %s  %d (%s) peer=%d\n", inv.ToString(),
              nRequestTime,
              DateTimeStrFormat("%H:%M:%S", nRequestTime / 1000000), id);
 
     // Make sure not to reuse time indexes to keep things in the same order
     int64_t nNow = GetTimeMicros() - 1000000;
     static int64_t nLastTime;
     ++nLastTime;
     nNow = std::max(nNow, nLastTime);
     nLastTime = nNow;
 
     // Each retry is 2 minutes after the last
     nRequestTime = std::max(nRequestTime + 2 * 60 * 1000000, nNow);
     if (it != mapAlreadyAskedFor.end()) {
         mapAlreadyAskedFor.update(it, nRequestTime);
     } else {
         mapAlreadyAskedFor.insert(std::make_pair(inv.hash, nRequestTime));
     }
     mapAskFor.insert(std::make_pair(nRequestTime, inv));
 }
 
 bool CConnman::NodeFullyConnected(const CNode *pnode) {
     return pnode && pnode->fSuccessfullyConnected && !pnode->fDisconnect;
 }
 
 void CConnman::PushMessage(CNode *pnode, CSerializedNetMsg &&msg) {
     size_t nMessageSize = msg.data.size();
     size_t nTotalSize = nMessageSize + CMessageHeader::HEADER_SIZE;
     LogPrint(BCLog::NET, "sending %s (%d bytes) peer=%d\n",
              SanitizeString(msg.command.c_str()), nMessageSize, pnode->id);
 
     std::vector<uint8_t> serializedHeader;
     serializedHeader.reserve(CMessageHeader::HEADER_SIZE);
     uint256 hash = Hash(msg.data.data(), msg.data.data() + nMessageSize);
     CMessageHeader hdr(config->GetChainParams().NetMagic(), msg.command.c_str(),
                        nMessageSize);
     memcpy(hdr.pchChecksum, hash.begin(), CMessageHeader::CHECKSUM_SIZE);
 
     CVectorWriter{SER_NETWORK, INIT_PROTO_VERSION, serializedHeader, 0, hdr};
 
     size_t nBytesSent = 0;
     {
         LOCK(pnode->cs_vSend);
         bool optimisticSend(pnode->vSendMsg.empty());
 
         // log total amount of bytes per command
         pnode->mapSendBytesPerMsgCmd[msg.command] += nTotalSize;
         pnode->nSendSize += nTotalSize;
 
         if (pnode->nSendSize > nSendBufferMaxSize) {
             pnode->fPauseSend = true;
         }
         pnode->vSendMsg.push_back(std::move(serializedHeader));
         if (nMessageSize) {
             pnode->vSendMsg.push_back(std::move(msg.data));
         }
 
         // If write queue empty, attempt "optimistic write"
         if (optimisticSend == true) {
             nBytesSent = SocketSendData(pnode);
         }
     }
     if (nBytesSent) {
         RecordBytesSent(nBytesSent);
     }
 }
 
 bool CConnman::ForNode(NodeId id, std::function<bool(CNode *pnode)> func) {
     CNode *found = nullptr;
     LOCK(cs_vNodes);
     for (auto &&pnode : vNodes) {
         if (pnode->id == id) {
             found = pnode;
             break;
         }
     }
     return found != nullptr && NodeFullyConnected(found) && func(found);
 }
 
 int64_t PoissonNextSend(int64_t nNow, int average_interval_seconds) {
     return nNow + int64_t(log1p(GetRand(1ULL << 48) *
                                 -0.0000000000000035527136788 /* -1/2^48 */) *
                               average_interval_seconds * -1000000.0 +
                           0.5);
 }
 
 CSipHasher CConnman::GetDeterministicRandomizer(uint64_t id) const {
     return CSipHasher(nSeed0, nSeed1).Write(id);
 }
 
 uint64_t CConnman::CalculateKeyedNetGroup(const CAddress &ad) const {
     std::vector<uint8_t> vchNetGroup(ad.GetGroup());
 
     return GetDeterministicRandomizer(RANDOMIZER_ID_NETGROUP)
         .Write(&vchNetGroup[0], vchNetGroup.size())
         .Finalize();
 }
 
 /**
  * This function convert MaxBlockSize from byte to
  * MB with a decimal precision one digit rounded down
  * E.g.
  * 1660000 -> 1.6
  * 2010000 -> 2.0
  * 1000000 -> 1.0
  * 230000  -> 0.2
  * 50000   -> 0.0
  *
  *  NB behavior for EB<1MB not standardized yet still
  *  the function applies the same algo used for
  *  EB greater or equal to 1MB
  */
 std::string getSubVersionEB(uint64_t MaxBlockSize) {
     // Prepare EB string we are going to add to SubVer:
     // 1) translate from byte to MB and convert to string
     // 2) limit the EB string to the first decimal digit (floored)
     std::stringstream ebMBs;
     ebMBs << (MaxBlockSize / (ONE_MEGABYTE / 10));
     std::string eb = ebMBs.str();
     eb.insert(eb.size() - 1, ".", 1);
     if (eb.substr(0, 1) == ".") {
         eb = "0" + eb;
     }
     return eb;
 }
 
 std::string userAgent(const Config &config) {
     // format excessive blocksize value
     std::string eb = getSubVersionEB(config.GetMaxBlockSize());
     std::vector<std::string> uacomments;
     uacomments.push_back("EB" + eb);
 
     // sanitize comments per BIP-0014, format user agent and check total size
     if (gArgs.IsArgSet("-uacomment")) {
         for (const std::string &cmt : gArgs.GetArgs("-uacomment")) {
             if (cmt != SanitizeString(cmt, SAFE_CHARS_UA_COMMENT)) {
                 LogPrintf(
                     "User Agent comment (%s) contains unsafe characters. "
                     "We are going to use a sanitize version of the comment.\n",
                     cmt);
             }
             uacomments.push_back(cmt);
         }
     }
 
     std::string subversion =
         FormatSubVersion(CLIENT_NAME, CLIENT_VERSION, uacomments);
     if (subversion.size() > MAX_SUBVERSION_LENGTH) {
         LogPrintf("Total length of network version string (%i) exceeds maximum "
                   "length (%i). Reduce the number or size of uacomments. "
                   "String has been resized to the max length allowed.\n",
                   subversion.size(), MAX_SUBVERSION_LENGTH);
         subversion.resize(MAX_SUBVERSION_LENGTH - 2);
         subversion.append(")/");
         LogPrintf("Current network string has been set to: %s\n", subversion);
     }
 
     return subversion;
 }
diff --git a/src/net.h b/src/net.h
index 43f8de127..0820d386a 100644
--- a/src/net.h
+++ b/src/net.h
@@ -1,826 +1,821 @@
 // Copyright (c) 2009-2010 Satoshi Nakamoto
 // Copyright (c) 2009-2016 The Bitcoin Core developers
 // Copyright (c) 2017 The Bitcoin developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #ifndef BITCOIN_NET_H
 #define BITCOIN_NET_H
 
 #include "addrdb.h"
 #include "addrman.h"
 #include "amount.h"
 #include "bloom.h"
 #include "chainparams.h"
 #include "compat.h"
 #include "fs.h"
 #include "hash.h"
 #include "limitedmap.h"
 #include "netaddress.h"
 #include "protocol.h"
 #include "random.h"
 #include "streams.h"
 #include "sync.h"
 #include "threadinterrupt.h"
 #include "uint256.h"
 
 #include <atomic>
 #include <condition_variable>
 #include <cstdint>
 #include <deque>
 #include <memory>
 #include <thread>
 
 #ifndef WIN32
 #include <arpa/inet.h>
 #endif
 
 #include <boost/signals2/signal.hpp>
 
 class CAddrMan;
 class Config;
 class CNode;
 class CScheduler;
 
 namespace boost {
 class thread_group;
 } // namespace boost
 
 /** Time between pings automatically sent out for latency probing and keepalive
  * (in seconds). */
 static const int PING_INTERVAL = 2 * 60;
 /** Time after which to disconnect, after waiting for a ping response (or
  * inactivity). */
 static const int TIMEOUT_INTERVAL = 20 * 60;
 /** Run the feeler connection loop once every 2 minutes or 120 seconds. **/
 static const int FEELER_INTERVAL = 120;
 /** The maximum number of entries in an 'inv' protocol message */
 static const unsigned int MAX_INV_SZ = 50000;
 /** The maximum number of new addresses to accumulate before announcing. */
 static const unsigned int MAX_ADDR_TO_SEND = 1000;
-/**
- * Maximum length of incoming protocol messages (Currently 1MB).
- * NB: Messages propagating block content are not subject to this limit.
- */
-static const unsigned int MAX_PROTOCOL_MESSAGE_LENGTH = 1 * 1024 * 1024;
 /** Maximum length of strSubVer in `version` message */
 static const unsigned int MAX_SUBVERSION_LENGTH = 256;
 /** Maximum number of automatic outgoing nodes */
 static const int MAX_OUTBOUND_CONNECTIONS = 8;
 /** Maximum number of addnode outgoing nodes */
 static const int MAX_ADDNODE_CONNECTIONS = 8;
 /** -listen default */
 static const bool DEFAULT_LISTEN = true;
 /** -upnp default */
 #ifdef USE_UPNP
 static const bool DEFAULT_UPNP = USE_UPNP;
 #else
 static const bool DEFAULT_UPNP = false;
 #endif
 /** The maximum number of entries in mapAskFor */
 static const size_t MAPASKFOR_MAX_SZ = MAX_INV_SZ;
 /** The maximum number of entries in setAskFor (larger due to getdata latency)*/
 static const size_t SETASKFOR_MAX_SZ = 2 * MAX_INV_SZ;
 /** The maximum number of peer connections to maintain. */
 static const unsigned int DEFAULT_MAX_PEER_CONNECTIONS = 125;
 /** The default for -maxuploadtarget. 0 = Unlimited */
 static const uint64_t DEFAULT_MAX_UPLOAD_TARGET = 0;
 /** The default timeframe for -maxuploadtarget. 1 day. */
 static const uint64_t MAX_UPLOAD_TIMEFRAME = 60 * 60 * 24;
 /** Default for blocks only*/
 static const bool DEFAULT_BLOCKSONLY = false;
 
 // Force DNS seed use ahead of UAHF fork, to ensure peers are found
 // as long as seeders are working.
 // TODO: Change this back to false after the forked network is stable.
 static const bool DEFAULT_FORCEDNSSEED = true;
 static const size_t DEFAULT_MAXRECEIVEBUFFER = 5 * 1000;
 static const size_t DEFAULT_MAXSENDBUFFER = 1 * 1000;
 
 static const ServiceFlags REQUIRED_SERVICES = ServiceFlags(NODE_NETWORK);
 
 // Default 24-hour ban.
 // NOTE: When adjusting this, update rpcnet:setban's help ("24h")
 static const unsigned int DEFAULT_MISBEHAVING_BANTIME = 60 * 60 * 24;
 
 typedef int64_t NodeId;
 
 struct AddedNodeInfo {
     std::string strAddedNode;
     CService resolvedAddress;
     bool fConnected;
     bool fInbound;
 };
 
 class CTransaction;
 class CNodeStats;
 class CClientUIInterface;
 
 struct CSerializedNetMsg {
     CSerializedNetMsg() = default;
     CSerializedNetMsg(CSerializedNetMsg &&) = default;
     CSerializedNetMsg &operator=(CSerializedNetMsg &&) = default;
     // No copying, only moves.
     CSerializedNetMsg(const CSerializedNetMsg &msg) = delete;
     CSerializedNetMsg &operator=(const CSerializedNetMsg &) = delete;
 
     std::vector<uint8_t> data;
     std::string command;
 };
 
 class CConnman {
 public:
     enum NumConnections {
         CONNECTIONS_NONE = 0,
         CONNECTIONS_IN = (1U << 0),
         CONNECTIONS_OUT = (1U << 1),
         CONNECTIONS_ALL = (CONNECTIONS_IN | CONNECTIONS_OUT),
     };
 
     struct Options {
         ServiceFlags nLocalServices = NODE_NONE;
         ServiceFlags nRelevantServices = NODE_NONE;
         int nMaxConnections = 0;
         int nMaxOutbound = 0;
         int nMaxAddnode = 0;
         int nMaxFeeler = 0;
         int nBestHeight = 0;
         CClientUIInterface *uiInterface = nullptr;
         unsigned int nSendBufferMaxSize = 0;
         unsigned int nReceiveFloodSize = 0;
         uint64_t nMaxOutboundTimeframe = 0;
         uint64_t nMaxOutboundLimit = 0;
     };
     CConnman(const Config &configIn, uint64_t seed0, uint64_t seed1);
     ~CConnman();
     bool Start(CScheduler &scheduler, std::string &strNodeError,
                Options options);
     void Stop();
     void Interrupt();
     bool BindListenPort(const CService &bindAddr, std::string &strError,
                         bool fWhitelisted = false);
     bool GetNetworkActive() const { return fNetworkActive; };
     void SetNetworkActive(bool active);
     bool OpenNetworkConnection(const CAddress &addrConnect, bool fCountFailure,
                                CSemaphoreGrant *grantOutbound = nullptr,
                                const char *strDest = nullptr,
                                bool fOneShot = false, bool fFeeler = false,
                                bool fAddnode = false);
     bool CheckIncomingNonce(uint64_t nonce);
 
     bool ForNode(NodeId id, std::function<bool(CNode *pnode)> func);
 
     void PushMessage(CNode *pnode, CSerializedNetMsg &&msg);
 
     template <typename Callable> void ForEachNode(Callable &&func) {
         LOCK(cs_vNodes);
         for (auto &&node : vNodes) {
             if (NodeFullyConnected(node)) func(node);
         }
     };
 
     template <typename Callable> void ForEachNode(Callable &&func) const {
         LOCK(cs_vNodes);
         for (auto &&node : vNodes) {
             if (NodeFullyConnected(node)) func(node);
         }
     };
 
     template <typename Callable, typename CallableAfter>
     void ForEachNodeThen(Callable &&pre, CallableAfter &&post) {
         LOCK(cs_vNodes);
         for (auto &&node : vNodes) {
             if (NodeFullyConnected(node)) pre(node);
         }
         post();
     };
 
     template <typename Callable, typename CallableAfter>
     void ForEachNodeThen(Callable &&pre, CallableAfter &&post) const {
         LOCK(cs_vNodes);
         for (auto &&node : vNodes) {
             if (NodeFullyConnected(node)) pre(node);
         }
         post();
     };
 
     // Addrman functions
     size_t GetAddressCount() const;
     void SetServices(const CService &addr, ServiceFlags nServices);
     void MarkAddressGood(const CAddress &addr);
     void AddNewAddress(const CAddress &addr, const CAddress &addrFrom,
                        int64_t nTimePenalty = 0);
     void AddNewAddresses(const std::vector<CAddress> &vAddr,
                          const CAddress &addrFrom, int64_t nTimePenalty = 0);
     std::vector<CAddress> GetAddresses();
     void AddressCurrentlyConnected(const CService &addr);
 
     // Denial-of-service detection/prevention. The idea is to detect peers that
     // are behaving badly and disconnect/ban them, but do it in a
     // one-coding-mistake-won't-shatter-the-entire-network way.
     // IMPORTANT: There should be nothing I can give a node that it will forward
     // on that will make that node's peers drop it. If there is, an attacker can
     // isolate a node and/or try to split the network. Dropping a node for
     // sending stuff that is invalid now but might be valid in a later version
     // is also dangerous, because it can cause a network split between nodes
     // running old code and nodes running new code.
     void Ban(const CNetAddr &netAddr, const BanReason &reason,
              int64_t bantimeoffset = 0, bool sinceUnixEpoch = false);
     void Ban(const CSubNet &subNet, const BanReason &reason,
              int64_t bantimeoffset = 0, bool sinceUnixEpoch = false);
     // Needed for unit testing.
     void ClearBanned();
     bool IsBanned(CNetAddr ip);
     bool IsBanned(CSubNet subnet);
     bool Unban(const CNetAddr &ip);
     bool Unban(const CSubNet &ip);
     void GetBanned(banmap_t &banmap);
     void SetBanned(const banmap_t &banmap);
 
     void AddOneShot(const std::string &strDest);
 
     bool AddNode(const std::string &node);
     bool RemoveAddedNode(const std::string &node);
     std::vector<AddedNodeInfo> GetAddedNodeInfo();
 
     size_t GetNodeCount(NumConnections num);
     void GetNodeStats(std::vector<CNodeStats> &vstats);
     bool DisconnectNode(const std::string &node);
     bool DisconnectNode(NodeId id);
 
     unsigned int GetSendBufferSize() const;
 
     void AddWhitelistedRange(const CSubNet &subnet);
 
     ServiceFlags GetLocalServices() const;
 
     //! set the max outbound target in bytes.
     void SetMaxOutboundTarget(uint64_t limit);
     uint64_t GetMaxOutboundTarget();
 
     //! set the timeframe for the max outbound target.
     void SetMaxOutboundTimeframe(uint64_t timeframe);
     uint64_t GetMaxOutboundTimeframe();
 
     //! check if the outbound target is reached.
     // If param historicalBlockServingLimit is set true, the function will
     // response true if the limit for serving historical blocks has been
     // reached.
     bool OutboundTargetReached(bool historicalBlockServingLimit);
 
     //! response the bytes left in the current max outbound cycle
     // in case of no limit, it will always response 0
     uint64_t GetOutboundTargetBytesLeft();
 
     //! response the time in second left in the current max outbound cycle
     // in case of no limit, it will always response 0
     uint64_t GetMaxOutboundTimeLeftInCycle();
 
     uint64_t GetTotalBytesRecv();
     uint64_t GetTotalBytesSent();
 
     void SetBestHeight(int height);
     int GetBestHeight() const;
 
     /** Get a unique deterministic randomizer. */
     CSipHasher GetDeterministicRandomizer(uint64_t id) const;
 
     unsigned int GetReceiveFloodSize() const;
 
     void WakeMessageHandler();
 
 private:
     struct ListenSocket {
         SOCKET socket;
         bool whitelisted;
 
         ListenSocket(SOCKET socket_, bool whitelisted_)
             : socket(socket_), whitelisted(whitelisted_) {}
     };
 
     void ThreadOpenAddedConnections();
     void ProcessOneShot();
     void ThreadOpenConnections();
     void ThreadMessageHandler();
     void AcceptConnection(const ListenSocket &hListenSocket);
     void ThreadSocketHandler();
     void ThreadDNSAddressSeed();
 
     uint64_t CalculateKeyedNetGroup(const CAddress &ad) const;
 
     CNode *FindNode(const CNetAddr &ip);
     CNode *FindNode(const CSubNet &subNet);
     CNode *FindNode(const std::string &addrName);
     CNode *FindNode(const CService &addr);
 
     bool AttemptToEvictConnection();
     CNode *ConnectNode(CAddress addrConnect, const char *pszDest,
                        bool fCountFailure);
     bool IsWhitelistedRange(const CNetAddr &addr);
 
     void DeleteNode(CNode *pnode);
 
     NodeId GetNewNodeId();
 
     size_t SocketSendData(CNode *pnode) const;
     //! check is the banlist has unwritten changes
     bool BannedSetIsDirty();
     //! set the "dirty" flag for the banlist
     void SetBannedSetDirty(bool dirty = true);
     //! clean unused entries (if bantime has expired)
     void SweepBanned();
     void DumpAddresses();
     void DumpData();
     void DumpBanlist();
 
     // Network stats
     void RecordBytesRecv(uint64_t bytes);
     void RecordBytesSent(uint64_t bytes);
 
     // Whether the node should be passed out in ForEach* callbacks
     static bool NodeFullyConnected(const CNode *pnode);
 
     const Config *config;
 
     // Network usage totals
     CCriticalSection cs_totalBytesRecv;
     CCriticalSection cs_totalBytesSent;
     uint64_t nTotalBytesRecv;
     uint64_t nTotalBytesSent;
 
     // outbound limit & stats
     uint64_t nMaxOutboundTotalBytesSentInCycle;
     uint64_t nMaxOutboundCycleStartTime;
     uint64_t nMaxOutboundLimit;
     uint64_t nMaxOutboundTimeframe;
 
     // Whitelisted ranges. Any node connecting from these is automatically
     // whitelisted (as well as those connecting to whitelisted binds).
     std::vector<CSubNet> vWhitelistedRange;
     CCriticalSection cs_vWhitelistedRange;
 
     unsigned int nSendBufferMaxSize;
     unsigned int nReceiveFloodSize;
 
     std::vector<ListenSocket> vhListenSocket;
     std::atomic<bool> fNetworkActive;
     banmap_t setBanned;
     CCriticalSection cs_setBanned;
     bool setBannedIsDirty;
     bool fAddressesInitialized;
     CAddrMan addrman;
     std::deque<std::string> vOneShots;
     CCriticalSection cs_vOneShots;
     std::vector<std::string> vAddedNodes;
     CCriticalSection cs_vAddedNodes;
     std::vector<CNode *> vNodes;
     std::list<CNode *> vNodesDisconnected;
     mutable CCriticalSection cs_vNodes;
     std::atomic<NodeId> nLastNodeId;
 
     /** Services this instance offers */
     ServiceFlags nLocalServices;
 
     /** Services this instance cares about */
     ServiceFlags nRelevantServices;
 
     CSemaphore *semOutbound;
     CSemaphore *semAddnode;
     int nMaxConnections;
     int nMaxOutbound;
     int nMaxAddnode;
     int nMaxFeeler;
     std::atomic<int> nBestHeight;
     CClientUIInterface *clientInterface;
 
     /** SipHasher seeds for deterministic randomness */
     const uint64_t nSeed0, nSeed1;
 
     /** flag for waking the message processor. */
     bool fMsgProcWake;
 
     std::condition_variable condMsgProc;
     std::mutex mutexMsgProc;
     std::atomic<bool> flagInterruptMsgProc;
 
     CThreadInterrupt interruptNet;
 
     std::thread threadDNSAddressSeed;
     std::thread threadSocketHandler;
     std::thread threadOpenAddedConnections;
     std::thread threadOpenConnections;
     std::thread threadMessageHandler;
 };
 extern std::unique_ptr<CConnman> g_connman;
 void Discover(boost::thread_group &threadGroup);
 void MapPort(bool fUseUPnP);
 unsigned short GetListenPort();
 bool BindListenPort(const CService &bindAddr, std::string &strError,
                     bool fWhitelisted = false);
 
 struct CombinerAll {
     typedef bool result_type;
 
     template <typename I> bool operator()(I first, I last) const {
         while (first != last) {
             if (!(*first)) {
                 return false;
             }
             ++first;
         }
         return true;
     }
 };
 
 // Signals for message handling
 struct CNodeSignals {
     boost::signals2::signal<bool(const Config &, CNode *, CConnman &,
                                  std::atomic<bool> &),
                             CombinerAll>
         ProcessMessages;
     boost::signals2::signal<bool(const Config &, CNode *, CConnman &,
                                  std::atomic<bool> &),
                             CombinerAll>
         SendMessages;
     boost::signals2::signal<void(const Config &, CNode *, CConnman &)>
         InitializeNode;
     boost::signals2::signal<void(NodeId, bool &)> FinalizeNode;
 };
 
 CNodeSignals &GetNodeSignals();
 
 enum {
     // unknown
     LOCAL_NONE,
     // address a local interface listens on
     LOCAL_IF,
     // address explicit bound to
     LOCAL_BIND,
     // address reported by UPnP
     LOCAL_UPNP,
     // address explicitly specified (-externalip=)
     LOCAL_MANUAL,
 
     LOCAL_MAX
 };
 
 bool IsPeerAddrLocalGood(CNode *pnode);
 void AdvertiseLocal(CNode *pnode);
 void SetLimited(enum Network net, bool fLimited = true);
 bool IsLimited(enum Network net);
 bool IsLimited(const CNetAddr &addr);
 bool AddLocal(const CService &addr, int nScore = LOCAL_NONE);
 bool AddLocal(const CNetAddr &addr, int nScore = LOCAL_NONE);
 bool RemoveLocal(const CService &addr);
 bool SeenLocal(const CService &addr);
 bool IsLocal(const CService &addr);
 bool GetLocal(CService &addr, const CNetAddr *paddrPeer = nullptr);
 bool IsReachable(enum Network net);
 bool IsReachable(const CNetAddr &addr);
 CAddress GetLocalAddress(const CNetAddr *paddrPeer,
                          ServiceFlags nLocalServices);
 
 extern bool fDiscover;
 extern bool fListen;
 extern bool fRelayTxes;
 
 extern limitedmap<uint256, int64_t> mapAlreadyAskedFor;
 
 struct LocalServiceInfo {
     int nScore;
     int nPort;
 };
 
 extern CCriticalSection cs_mapLocalHost;
 extern std::map<CNetAddr, LocalServiceInfo> mapLocalHost;
 
 // Command, total bytes
 typedef std::map<std::string, uint64_t> mapMsgCmdSize;
 
 class CNodeStats {
 public:
     NodeId nodeid;
     ServiceFlags nServices;
     bool fRelayTxes;
     int64_t nLastSend;
     int64_t nLastRecv;
     int64_t nTimeConnected;
     int64_t nTimeOffset;
     std::string addrName;
     int nVersion;
     std::string cleanSubVer;
     bool fInbound;
     bool fAddnode;
     int nStartingHeight;
     uint64_t nSendBytes;
     mapMsgCmdSize mapSendBytesPerMsgCmd;
     uint64_t nRecvBytes;
     mapMsgCmdSize mapRecvBytesPerMsgCmd;
     bool fWhitelisted;
     double dPingTime;
     double dPingWait;
     double dMinPing;
     std::string addrLocal;
     CAddress addr;
 };
 
 class CNetMessage {
 private:
     mutable CHash256 hasher;
     mutable uint256 data_hash;
 
 public:
     // Parsing header (false) or data (true)
     bool in_data;
 
     // Partially received header.
     CDataStream hdrbuf;
     // Complete header.
     CMessageHeader hdr;
     unsigned int nHdrPos;
 
     // Received message data.
     CDataStream vRecv;
     unsigned int nDataPos;
 
     // Time (in microseconds) of message receipt.
     int64_t nTime;
 
     CNetMessage(const CMessageHeader::MessageMagic &pchMessageStartIn,
                 int nTypeIn, int nVersionIn)
         : hdrbuf(nTypeIn, nVersionIn), hdr(pchMessageStartIn),
           vRecv(nTypeIn, nVersionIn) {
         hdrbuf.resize(24);
         in_data = false;
         nHdrPos = 0;
         nDataPos = 0;
         nTime = 0;
     }
 
     bool complete() const {
         if (!in_data) {
             return false;
         }
 
         return (hdr.nMessageSize == nDataPos);
     }
 
     const uint256 &GetMessageHash() const;
 
     void SetVersion(int nVersionIn) {
         hdrbuf.SetVersion(nVersionIn);
         vRecv.SetVersion(nVersionIn);
     }
 
-    int readHeader(const char *pch, unsigned int nBytes);
+    int readHeader(const Config &config, const char *pch, unsigned int nBytes);
     int readData(const char *pch, unsigned int nBytes);
 };
 
 /** Information about a peer */
 class CNode {
     friend class CConnman;
 
 public:
     // socket
     std::atomic<ServiceFlags> nServices;
     // Services expected from a peer, otherwise it will be disconnected
     ServiceFlags nServicesExpected;
     SOCKET hSocket;
     // Total size of all vSendMsg entries.
     size_t nSendSize;
     // Offset inside the first vSendMsg already sent.
     size_t nSendOffset;
     uint64_t nSendBytes;
     std::deque<std::vector<uint8_t>> vSendMsg;
     CCriticalSection cs_vSend;
     CCriticalSection cs_hSocket;
     CCriticalSection cs_vRecv;
 
     CCriticalSection cs_vProcessMsg;
     std::list<CNetMessage> vProcessMsg;
     size_t nProcessQueueSize;
 
     CCriticalSection cs_sendProcessing;
 
     std::deque<CInv> vRecvGetData;
     uint64_t nRecvBytes;
     std::atomic<int> nRecvVersion;
 
     std::atomic<int64_t> nLastSend;
     std::atomic<int64_t> nLastRecv;
     const int64_t nTimeConnected;
     std::atomic<int64_t> nTimeOffset;
     const CAddress addr;
     std::atomic<int> nVersion;
     // strSubVer is whatever byte array we read from the wire. However, this
     // field is intended to be printed out, displayed to humans in various forms
     // and so on. So we sanitize it and store the sanitized version in
     // cleanSubVer. The original should be used when dealing with the network or
     // wire types and the cleaned string used when displayed or logged.
     std::string strSubVer, cleanSubVer;
     // Used for both cleanSubVer and strSubVer.
     CCriticalSection cs_SubVer;
     // This peer can bypass DoS banning.
     bool fWhitelisted;
     // If true this node is being used as a short lived feeler.
     bool fFeeler;
     bool fOneShot;
     bool fAddnode;
     bool fClient;
     const bool fInbound;
     std::atomic_bool fSuccessfullyConnected;
     std::atomic_bool fDisconnect;
     // We use fRelayTxes for two purposes -
     // a) it allows us to not relay tx invs before receiving the peer's version
     // message.
     // b) the peer may tell us in its version message that we should not relay
     // tx invs unless it loads a bloom filter.
 
     // protected by cs_filter
     bool fRelayTxes;
     bool fSentAddr;
     CSemaphoreGrant grantOutbound;
     CCriticalSection cs_filter;
     CBloomFilter *pfilter;
     std::atomic<int> nRefCount;
     const NodeId id;
 
     const uint64_t nKeyedNetGroup;
     std::atomic_bool fPauseRecv;
     std::atomic_bool fPauseSend;
 
 protected:
     mapMsgCmdSize mapSendBytesPerMsgCmd;
     mapMsgCmdSize mapRecvBytesPerMsgCmd;
 
 public:
     uint256 hashContinue;
     std::atomic<int> nStartingHeight;
 
     // flood relay
     std::vector<CAddress> vAddrToSend;
     CRollingBloomFilter addrKnown;
     bool fGetAddr;
     std::set<uint256> setKnown;
     int64_t nNextAddrSend;
     int64_t nNextLocalAddrSend;
 
     // Inventory based relay.
     CRollingBloomFilter filterInventoryKnown;
     // Set of transaction ids we still have to announce. They are sorted by the
     // mempool before relay, so the order is not important.
     std::set<uint256> setInventoryTxToSend;
     // List of block ids we still have announce. There is no final sorting
     // before sending, as they are always sent immediately and in the order
     // requested.
     std::vector<uint256> vInventoryBlockToSend;
     CCriticalSection cs_inventory;
     std::set<uint256> setAskFor;
     std::multimap<int64_t, CInv> mapAskFor;
     int64_t nNextInvSend;
     // Used for headers announcements - unfiltered blocks to relay. Also
     // protected by cs_inventory.
     std::vector<uint256> vBlockHashesToAnnounce;
     // Used for BIP35 mempool sending, also protected by cs_inventory.
     bool fSendMempool;
 
     // Last time a "MEMPOOL" request was serviced.
     std::atomic<int64_t> timeLastMempoolReq;
 
     // Block and TXN accept times
     std::atomic<int64_t> nLastBlockTime;
     std::atomic<int64_t> nLastTXTime;
 
     // Ping time measurement:
     // The pong reply we're expecting, or 0 if no pong expected.
     std::atomic<uint64_t> nPingNonceSent;
     // Time (in usec) the last ping was sent, or 0 if no ping was ever sent.
     std::atomic<int64_t> nPingUsecStart;
     // Last measured round-trip time.
     std::atomic<int64_t> nPingUsecTime;
     // Best measured round-trip time.
     std::atomic<int64_t> nMinPingUsecTime;
     // Whether a ping is requested.
     std::atomic<bool> fPingQueued;
     // Minimum fee rate with which to filter inv's to this node
     Amount minFeeFilter;
     CCriticalSection cs_feeFilter;
     Amount lastSentFeeFilter;
     int64_t nextSendTimeFeeFilter;
 
     CNode(NodeId id, ServiceFlags nLocalServicesIn, int nMyStartingHeightIn,
           SOCKET hSocketIn, const CAddress &addrIn, uint64_t nKeyedNetGroupIn,
           uint64_t nLocalHostNonceIn, const std::string &addrNameIn = "",
           bool fInboundIn = false);
     ~CNode();
 
 private:
     CNode(const CNode &);
     void operator=(const CNode &);
 
     const uint64_t nLocalHostNonce;
     // Services offered to this peer
     const ServiceFlags nLocalServices;
     const int nMyStartingHeight;
     int nSendVersion;
     // Used only by SocketHandler thread.
     std::list<CNetMessage> vRecvMsg;
 
     mutable CCriticalSection cs_addrName;
     std::string addrName;
 
     CService addrLocal;
     mutable CCriticalSection cs_addrLocal;
 
 public:
     NodeId GetId() const { return id; }
 
     uint64_t GetLocalNonce() const { return nLocalHostNonce; }
 
     int GetMyStartingHeight() const { return nMyStartingHeight; }
 
     int GetRefCount() {
         assert(nRefCount >= 0);
         return nRefCount;
     }
 
     bool ReceiveMsgBytes(const Config &config, const char *pch,
                          unsigned int nBytes, bool &complete);
 
     void SetRecvVersion(int nVersionIn) { nRecvVersion = nVersionIn; }
     int GetRecvVersion() { return nRecvVersion; }
     void SetSendVersion(int nVersionIn);
     int GetSendVersion() const;
 
     CService GetAddrLocal() const;
     //! May not be called more than once
     void SetAddrLocal(const CService &addrLocalIn);
 
     CNode *AddRef() {
         nRefCount++;
         return this;
     }
 
     void Release() { nRefCount--; }
 
     void AddAddressKnown(const CAddress &_addr) {
         addrKnown.insert(_addr.GetKey());
     }
 
     void PushAddress(const CAddress &_addr, FastRandomContext &insecure_rand) {
         // Known checking here is only to save space from duplicates.
         // SendMessages will filter it again for knowns that were added
         // after addresses were pushed.
         if (_addr.IsValid() && !addrKnown.contains(_addr.GetKey())) {
             if (vAddrToSend.size() >= MAX_ADDR_TO_SEND) {
                 vAddrToSend[insecure_rand.randrange(vAddrToSend.size())] =
                     _addr;
             } else {
                 vAddrToSend.push_back(_addr);
             }
         }
     }
 
     void AddInventoryKnown(const CInv &inv) {
         LOCK(cs_inventory);
         filterInventoryKnown.insert(inv.hash);
     }
 
     void PushInventory(const CInv &inv) {
         LOCK(cs_inventory);
         if (inv.type == MSG_TX) {
             if (!filterInventoryKnown.contains(inv.hash)) {
                 setInventoryTxToSend.insert(inv.hash);
             }
         } else if (inv.type == MSG_BLOCK) {
             vInventoryBlockToSend.push_back(inv.hash);
         }
     }
 
     void PushBlockHash(const uint256 &hash) {
         LOCK(cs_inventory);
         vBlockHashesToAnnounce.push_back(hash);
     }
 
     void AskFor(const CInv &inv);
 
     void CloseSocketDisconnect();
 
     void copyStats(CNodeStats &stats);
 
     ServiceFlags GetLocalServices() const { return nLocalServices; }
 
     std::string GetAddrName() const;
     //! Sets the addrName only if it was not previously set
     void MaybeSetAddrName(const std::string &addrNameIn);
 };
 
 /**
  * Return a timestamp in the future (in microseconds) for exponentially
  * distributed events.
  */
 int64_t PoissonNextSend(int64_t nNow, int average_interval_seconds);
 
 std::string getSubVersionEB(uint64_t MaxBlockSize);
 std::string userAgent(const Config &config);
 #endif // BITCOIN_NET_H
diff --git a/src/net_processing.cpp b/src/net_processing.cpp
index 2f456f187..c3d5ab06f 100644
--- a/src/net_processing.cpp
+++ b/src/net_processing.cpp
@@ -1,3840 +1,3840 @@
 // Copyright (c) 2009-2010 Satoshi Nakamoto
 // Copyright (c) 2009-2016 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include "net_processing.h"
 
 #include "addrman.h"
 #include "arith_uint256.h"
 #include "blockencodings.h"
 #include "chainparams.h"
 #include "config.h"
 #include "consensus/validation.h"
 #include "hash.h"
 #include "init.h"
 #include "merkleblock.h"
 #include "net.h"
 #include "netbase.h"
 #include "netmessagemaker.h"
 #include "policy/fees.h"
 #include "policy/policy.h"
 #include "primitives/block.h"
 #include "primitives/transaction.h"
 #include "random.h"
 #include "tinyformat.h"
 #include "txmempool.h"
 #include "ui_interface.h"
 #include "util.h"
 #include "utilmoneystr.h"
 #include "utilstrencodings.h"
 #include "validation.h"
 #include "validationinterface.h"
 
 #include <boost/range/adaptor/reversed.hpp>
 #include <boost/thread.hpp>
 
 #if defined(NDEBUG)
 #error "Bitcoin cannot be compiled without assertions."
 #endif
 
 // Used only to inform the wallet of when we last received a block.
 std::atomic<int64_t> nTimeBestReceived(0);
 
 struct IteratorComparator {
     template <typename I> bool operator()(const I &a, const I &b) {
         return &(*a) < &(*b);
     }
 };
 
 struct COrphanTx {
     // When modifying, adapt the copy of this definition in tests/DoS_tests.
     CTransactionRef tx;
     NodeId fromPeer;
     int64_t nTimeExpire;
 };
 std::map<uint256, COrphanTx> mapOrphanTransactions GUARDED_BY(cs_main);
 std::map<COutPoint,
          std::set<std::map<uint256, COrphanTx>::iterator, IteratorComparator>>
     mapOrphanTransactionsByPrev GUARDED_BY(cs_main);
 void EraseOrphansFor(NodeId peer) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
 static size_t vExtraTxnForCompactIt = 0;
 static std::vector<std::pair<uint256, CTransactionRef>>
     vExtraTxnForCompact GUARDED_BY(cs_main);
 
 // SHA256("main address relay")[0:8]
 static const uint64_t RANDOMIZER_ID_ADDRESS_RELAY = 0x3cac0035b5866b90ULL;
 
 // Internal stuff
 namespace {
 /** Number of nodes with fSyncStarted. */
 int nSyncStarted = 0;
 
 /**
  * Sources of received blocks, saved to be able to send them reject messages or
  * ban them when processing happens afterwards. Protected by cs_main.
  * Set mapBlockSource[hash].second to false if the node should not be punished
  * if the block is invalid.
  */
 std::map<uint256, std::pair<NodeId, bool>> mapBlockSource;
 
 /**
  * Filter for transactions that were recently rejected by AcceptToMemoryPool.
  * These are not rerequested until the chain tip changes, at which point the
  * entire filter is reset. Protected by cs_main.
  *
  * Without this filter we'd be re-requesting txs from each of our peers,
  * increasing bandwidth consumption considerably. For instance, with 100 peers,
  * half of which relay a tx we don't accept, that might be a 50x bandwidth
  * increase. A flooding attacker attempting to roll-over the filter using
  * minimum-sized, 60byte, transactions might manage to send 1000/sec if we have
  * fast peers, so we pick 120,000 to give our peers a two minute window to send
  * invs to us.
  *
  * Decreasing the false positive rate is fairly cheap, so we pick one in a
  * million to make it highly unlikely for users to have issues with this filter.
  *
  * Memory used: 1.3 MB
  */
 std::unique_ptr<CRollingBloomFilter> recentRejects;
 uint256 hashRecentRejectsChainTip;
 
 /** Blocks that are in flight, and that are in the queue to be downloaded.
  * Protected by cs_main. */
 struct QueuedBlock {
     uint256 hash;
     //!< Optional.
     const CBlockIndex *pindex;
     //!< Whether this block has validated headers at the time of request.
     bool fValidatedHeaders;
     //!< Optional, used for CMPCTBLOCK downloads
     std::unique_ptr<PartiallyDownloadedBlock> partialBlock;
 };
 std::map<uint256, std::pair<NodeId, std::list<QueuedBlock>::iterator>>
     mapBlocksInFlight;
 
 /** Stack of nodes which we have set to announce using compact blocks */
 std::list<NodeId> lNodesAnnouncingHeaderAndIDs;
 
 /** Number of preferable block download peers. */
 int nPreferredDownload = 0;
 
 /** Number of peers from which we're downloading blocks. */
 int nPeersWithValidatedDownloads = 0;
 
 /** Relay map, protected by cs_main. */
 typedef std::map<uint256, CTransactionRef> MapRelay;
 MapRelay mapRelay;
 /** Expiration-time ordered list of (expire time, relay map entry) pairs,
  * protected by cs_main). */
 std::deque<std::pair<int64_t, MapRelay::iterator>> vRelayExpiration;
 } // namespace
 
 //////////////////////////////////////////////////////////////////////////////
 //
 // Registration of network node signals.
 //
 
 namespace {
 
 struct CBlockReject {
     uint8_t chRejectCode;
     std::string strRejectReason;
     uint256 hashBlock;
 };
 
 /**
  * Maintain validation-specific state about nodes, protected by cs_main, instead
  * by CNode's own locks. This simplifies asynchronous operation, where
  * processing of incoming data is done after the ProcessMessage call returns,
  * and we're no longer holding the node's locks.
  */
 struct CNodeState {
     //! The peer's address
     const CService address;
     //! Whether we have a fully established connection.
     bool fCurrentlyConnected;
     //! Accumulated misbehaviour score for this peer.
     int nMisbehavior;
     //! Whether this peer should be disconnected and banned (unless
     //! whitelisted).
     bool fShouldBan;
     //! String name of this peer (debugging/logging purposes).
     const std::string name;
     //! List of asynchronously-determined block rejections to notify this peer
     //! about.
     std::vector<CBlockReject> rejects;
     //! The best known block we know this peer has announced.
     const CBlockIndex *pindexBestKnownBlock;
     //! The hash of the last unknown block this peer has announced.
     uint256 hashLastUnknownBlock;
     //! The last full block we both have.
     const CBlockIndex *pindexLastCommonBlock;
     //! The best header we have sent our peer.
     const CBlockIndex *pindexBestHeaderSent;
     //! Length of current-streak of unconnecting headers announcements
     int nUnconnectingHeaders;
     //! Whether we've started headers synchronization with this peer.
     bool fSyncStarted;
     //! Since when we're stalling block download progress (in microseconds), or
     //! 0.
     int64_t nStallingSince;
     std::list<QueuedBlock> vBlocksInFlight;
     //! When the first entry in vBlocksInFlight started downloading. Don't care
     //! when vBlocksInFlight is empty.
     int64_t nDownloadingSince;
     int nBlocksInFlight;
     int nBlocksInFlightValidHeaders;
     //! Whether we consider this a preferred download peer.
     bool fPreferredDownload;
     //! Whether this peer wants invs or headers (when possible) for block
     //! announcements.
     bool fPreferHeaders;
     //! Whether this peer wants invs or cmpctblocks (when possible) for block
     //! announcements.
     bool fPreferHeaderAndIDs;
     /**
      * Whether this peer will send us cmpctblocks if we request them.
      * This is not used to gate request logic, as we really only care about
      * fSupportsDesiredCmpctVersion, but is used as a flag to "lock in" the
      * version of compact blocks we send.
      */
     bool fProvidesHeaderAndIDs;
     /**
      * If we've announced NODE_WITNESS to this peer: whether the peer sends
      * witnesses in cmpctblocks/blocktxns, otherwise: whether this peer sends
      * non-witnesses in cmpctblocks/blocktxns.
      */
     bool fSupportsDesiredCmpctVersion;
 
     CNodeState(CAddress addrIn, std::string addrNameIn)
         : address(addrIn), name(addrNameIn) {
         fCurrentlyConnected = false;
         nMisbehavior = 0;
         fShouldBan = false;
         pindexBestKnownBlock = nullptr;
         hashLastUnknownBlock.SetNull();
         pindexLastCommonBlock = nullptr;
         pindexBestHeaderSent = nullptr;
         nUnconnectingHeaders = 0;
         fSyncStarted = false;
         nStallingSince = 0;
         nDownloadingSince = 0;
         nBlocksInFlight = 0;
         nBlocksInFlightValidHeaders = 0;
         fPreferredDownload = false;
         fPreferHeaders = false;
         fPreferHeaderAndIDs = false;
         fProvidesHeaderAndIDs = false;
         fSupportsDesiredCmpctVersion = false;
     }
 };
 
 /** Map maintaining per-node state. Requires cs_main. */
 std::map<NodeId, CNodeState> mapNodeState;
 
 // Requires cs_main.
 CNodeState *State(NodeId pnode) {
     std::map<NodeId, CNodeState>::iterator it = mapNodeState.find(pnode);
     if (it == mapNodeState.end()) {
         return nullptr;
     }
 
     return &it->second;
 }
 
 void UpdatePreferredDownload(CNode *node, CNodeState *state) {
     nPreferredDownload -= state->fPreferredDownload;
 
     // Whether this node should be marked as a preferred download node.
     state->fPreferredDownload = (!node->fInbound || node->fWhitelisted) &&
                                 !node->fOneShot && !node->fClient;
 
     nPreferredDownload += state->fPreferredDownload;
 }
 
 void PushNodeVersion(const Config &config, CNode *pnode, CConnman &connman,
                      int64_t nTime) {
     ServiceFlags nLocalNodeServices = pnode->GetLocalServices();
     uint64_t nonce = pnode->GetLocalNonce();
     int nNodeStartingHeight = pnode->GetMyStartingHeight();
     NodeId nodeid = pnode->GetId();
     CAddress addr = pnode->addr;
 
     CAddress addrYou = (addr.IsRoutable() && !IsProxy(addr)
                             ? addr
                             : CAddress(CService(), addr.nServices));
     CAddress addrMe = CAddress(CService(), nLocalNodeServices);
 
     connman.PushMessage(pnode,
                         CNetMsgMaker(INIT_PROTO_VERSION)
                             .Make(NetMsgType::VERSION, PROTOCOL_VERSION,
                                   (uint64_t)nLocalNodeServices, nTime, addrYou,
                                   addrMe, nonce, userAgent(config),
                                   nNodeStartingHeight, ::fRelayTxes));
 
     if (fLogIPs) {
         LogPrint(BCLog::NET, "send version message: version %d, blocks=%d, "
                              "us=%s, them=%s, peer=%d\n",
                  PROTOCOL_VERSION, nNodeStartingHeight, addrMe.ToString(),
                  addrYou.ToString(), nodeid);
     } else {
         LogPrint(
             BCLog::NET,
             "send version message: version %d, blocks=%d, us=%s, peer=%d\n",
             PROTOCOL_VERSION, nNodeStartingHeight, addrMe.ToString(), nodeid);
     }
 }
 
 void InitializeNode(const Config &config, CNode *pnode, CConnman &connman) {
     CAddress addr = pnode->addr;
     std::string addrName = pnode->GetAddrName();
     NodeId nodeid = pnode->GetId();
     {
         LOCK(cs_main);
         mapNodeState.emplace_hint(
             mapNodeState.end(), std::piecewise_construct,
             std::forward_as_tuple(nodeid),
             std::forward_as_tuple(addr, std::move(addrName)));
     }
 
     if (!pnode->fInbound) {
         PushNodeVersion(config, pnode, connman, GetTime());
     }
 }
 
 void FinalizeNode(NodeId nodeid, bool &fUpdateConnectionTime) {
     fUpdateConnectionTime = false;
     LOCK(cs_main);
     CNodeState *state = State(nodeid);
 
     if (state->fSyncStarted) {
         nSyncStarted--;
     }
 
     if (state->nMisbehavior == 0 && state->fCurrentlyConnected) {
         fUpdateConnectionTime = true;
     }
 
     for (const QueuedBlock &entry : state->vBlocksInFlight) {
         mapBlocksInFlight.erase(entry.hash);
     }
     // Get rid of stale mapBlockSource entries for this peer as they may leak
     // if we don't clean them up (I saw on the order of ~100 stale entries on
     // a full resynch in my testing -- these entries stay forever).
     // Performance note: most of the time mapBlockSource has 0 or 1 entries.
     // During synch of blockchain it may end up with as many as 1000 entries,
     // which still only takes ~1ms to iterate through on even old hardware.
     // So this memleak cleanup is not expensive and worth doing since even
     // small leaks are bad. :)
     for (auto it = mapBlockSource.begin(); it != mapBlockSource.end(); /*NA*/) {
         if (it->second.first == nodeid) {
             mapBlockSource.erase(it++);
         } else {
             ++it;
         }
     }
 
     EraseOrphansFor(nodeid);
     nPreferredDownload -= state->fPreferredDownload;
     nPeersWithValidatedDownloads -= (state->nBlocksInFlightValidHeaders != 0);
     assert(nPeersWithValidatedDownloads >= 0);
 
     mapNodeState.erase(nodeid);
 
     if (mapNodeState.empty()) {
         // Do a consistency check after the last peer is removed.
         assert(mapBlocksInFlight.empty());
         assert(nPreferredDownload == 0);
         assert(nPeersWithValidatedDownloads == 0);
     }
 }
 
 // Requires cs_main.
 // Returns a bool indicating whether we requested this block.
 // Also used if a block was /not/ received and timed out or started with another
 // peer.
 bool MarkBlockAsReceived(const uint256 &hash) {
     std::map<uint256,
              std::pair<NodeId, std::list<QueuedBlock>::iterator>>::iterator
         itInFlight = mapBlocksInFlight.find(hash);
     if (itInFlight != mapBlocksInFlight.end()) {
         CNodeState *state = State(itInFlight->second.first);
         state->nBlocksInFlightValidHeaders -=
             itInFlight->second.second->fValidatedHeaders;
         if (state->nBlocksInFlightValidHeaders == 0 &&
             itInFlight->second.second->fValidatedHeaders) {
             // Last validated block on the queue was received.
             nPeersWithValidatedDownloads--;
         }
         if (state->vBlocksInFlight.begin() == itInFlight->second.second) {
             // First block on the queue was received, update the start download
             // time for the next one
             state->nDownloadingSince =
                 std::max(state->nDownloadingSince, GetTimeMicros());
         }
         state->vBlocksInFlight.erase(itInFlight->second.second);
         state->nBlocksInFlight--;
         state->nStallingSince = 0;
         mapBlocksInFlight.erase(itInFlight);
         return true;
     }
 
     return false;
 }
 
 // Requires cs_main.
 // returns false, still setting pit, if the block was already in flight from the
 // same peer pit will only be valid as long as the same cs_main lock is being
 // held.
 static bool
 MarkBlockAsInFlight(const Config &config, NodeId nodeid, const uint256 &hash,
                     const Consensus::Params &consensusParams,
                     const CBlockIndex *pindex = nullptr,
                     std::list<QueuedBlock>::iterator **pit = nullptr) {
     CNodeState *state = State(nodeid);
     assert(state != nullptr);
 
     // Short-circuit most stuff in case its from the same node.
     std::map<uint256,
              std::pair<NodeId, std::list<QueuedBlock>::iterator>>::iterator
         itInFlight = mapBlocksInFlight.find(hash);
     if (itInFlight != mapBlocksInFlight.end() &&
         itInFlight->second.first == nodeid) {
         *pit = &itInFlight->second.second;
         return false;
     }
 
     // Make sure it's not listed somewhere already.
     MarkBlockAsReceived(hash);
 
     std::list<QueuedBlock>::iterator it = state->vBlocksInFlight.insert(
         state->vBlocksInFlight.end(),
         {hash, pindex, pindex != nullptr,
          std::unique_ptr<PartiallyDownloadedBlock>(
              pit ? new PartiallyDownloadedBlock(config, &mempool) : nullptr)});
     state->nBlocksInFlight++;
     state->nBlocksInFlightValidHeaders += it->fValidatedHeaders;
     if (state->nBlocksInFlight == 1) {
         // We're starting a block download (batch) from this peer.
         state->nDownloadingSince = GetTimeMicros();
     }
 
     if (state->nBlocksInFlightValidHeaders == 1 && pindex != nullptr) {
         nPeersWithValidatedDownloads++;
     }
 
     itInFlight = mapBlocksInFlight
                      .insert(std::make_pair(hash, std::make_pair(nodeid, it)))
                      .first;
 
     if (pit) {
         *pit = &itInFlight->second.second;
     }
 
     return true;
 }
 
 /** Check whether the last unknown block a peer advertised is not yet known. */
 void ProcessBlockAvailability(NodeId nodeid) {
     CNodeState *state = State(nodeid);
     assert(state != nullptr);
 
     if (!state->hashLastUnknownBlock.IsNull()) {
         BlockMap::iterator itOld =
             mapBlockIndex.find(state->hashLastUnknownBlock);
         if (itOld != mapBlockIndex.end() && itOld->second->nChainWork > 0) {
             if (state->pindexBestKnownBlock == nullptr ||
                 itOld->second->nChainWork >=
                     state->pindexBestKnownBlock->nChainWork) {
                 state->pindexBestKnownBlock = itOld->second;
             }
             state->hashLastUnknownBlock.SetNull();
         }
     }
 }
 
 /** Update tracking information about which blocks a peer is assumed to have. */
 void UpdateBlockAvailability(NodeId nodeid, const uint256 &hash) {
     CNodeState *state = State(nodeid);
     assert(state != nullptr);
 
     ProcessBlockAvailability(nodeid);
 
     BlockMap::iterator it = mapBlockIndex.find(hash);
     if (it != mapBlockIndex.end() && it->second->nChainWork > 0) {
         // An actually better block was announced.
         if (state->pindexBestKnownBlock == nullptr ||
             it->second->nChainWork >= state->pindexBestKnownBlock->nChainWork) {
             state->pindexBestKnownBlock = it->second;
         }
     } else {
         // An unknown block was announced; just assume that the latest one is
         // the best one.
         state->hashLastUnknownBlock = hash;
     }
 }
 
 void MaybeSetPeerAsAnnouncingHeaderAndIDs(NodeId nodeid, CConnman &connman) {
     AssertLockHeld(cs_main);
     CNodeState *nodestate = State(nodeid);
     if (!nodestate) {
         LogPrint(BCLog::NET, "node state unavailable: peer=%d\n", nodeid);
         return;
     }
     if (!nodestate->fProvidesHeaderAndIDs) {
         return;
     }
     for (std::list<NodeId>::iterator it = lNodesAnnouncingHeaderAndIDs.begin();
          it != lNodesAnnouncingHeaderAndIDs.end(); it++) {
         if (*it == nodeid) {
             lNodesAnnouncingHeaderAndIDs.erase(it);
             lNodesAnnouncingHeaderAndIDs.push_back(nodeid);
             return;
         }
     }
     connman.ForNode(nodeid, [&connman](CNode *pfrom) {
         bool fAnnounceUsingCMPCTBLOCK = false;
         uint64_t nCMPCTBLOCKVersion = 1;
         if (lNodesAnnouncingHeaderAndIDs.size() >= 3) {
             // As per BIP152, we only get 3 of our peers to announce
             // blocks using compact encodings.
             connman.ForNode(lNodesAnnouncingHeaderAndIDs.front(),
                             [&connman, fAnnounceUsingCMPCTBLOCK,
                              nCMPCTBLOCKVersion](CNode *pnodeStop) {
                                 connman.PushMessage(
                                     pnodeStop,
                                     CNetMsgMaker(pnodeStop->GetSendVersion())
                                         .Make(NetMsgType::SENDCMPCT,
                                               fAnnounceUsingCMPCTBLOCK,
                                               nCMPCTBLOCKVersion));
                                 return true;
                             });
             lNodesAnnouncingHeaderAndIDs.pop_front();
         }
         fAnnounceUsingCMPCTBLOCK = true;
         connman.PushMessage(pfrom,
                             CNetMsgMaker(pfrom->GetSendVersion())
                                 .Make(NetMsgType::SENDCMPCT,
                                       fAnnounceUsingCMPCTBLOCK,
                                       nCMPCTBLOCKVersion));
         lNodesAnnouncingHeaderAndIDs.push_back(pfrom->GetId());
         return true;
     });
 }
 
 // Requires cs_main
 bool CanDirectFetch(const Consensus::Params &consensusParams) {
     return chainActive.Tip()->GetBlockTime() >
            GetAdjustedTime() - consensusParams.nPowTargetSpacing * 20;
 }
 
 // Requires cs_main
 bool PeerHasHeader(CNodeState *state, const CBlockIndex *pindex) {
     if (state->pindexBestKnownBlock &&
         pindex == state->pindexBestKnownBlock->GetAncestor(pindex->nHeight)) {
         return true;
     }
     if (state->pindexBestHeaderSent &&
         pindex == state->pindexBestHeaderSent->GetAncestor(pindex->nHeight)) {
         return true;
     }
     return false;
 }
 
 /**
  * Update pindexLastCommonBlock and add not-in-flight missing successors to
  * vBlocks, until it has at most count entries.
  */
 void FindNextBlocksToDownload(NodeId nodeid, unsigned int count,
                               std::vector<const CBlockIndex *> &vBlocks,
                               NodeId &nodeStaller,
                               const Consensus::Params &consensusParams) {
     if (count == 0) {
         return;
     }
 
     vBlocks.reserve(vBlocks.size() + count);
     CNodeState *state = State(nodeid);
     assert(state != nullptr);
 
     // Make sure pindexBestKnownBlock is up to date, we'll need it.
     ProcessBlockAvailability(nodeid);
 
     if (state->pindexBestKnownBlock == nullptr ||
         state->pindexBestKnownBlock->nChainWork <
             chainActive.Tip()->nChainWork ||
         state->pindexBestKnownBlock->nChainWork < nMinimumChainWork) {
         // This peer has nothing interesting.
         return;
     }
 
     if (state->pindexLastCommonBlock == nullptr) {
         // Bootstrap quickly by guessing a parent of our best tip is the forking
         // point. Guessing wrong in either direction is not a problem.
         state->pindexLastCommonBlock = chainActive[std::min(
             state->pindexBestKnownBlock->nHeight, chainActive.Height())];
     }
 
     // If the peer reorganized, our previous pindexLastCommonBlock may not be an
     // ancestor of its current tip anymore. Go back enough to fix that.
     state->pindexLastCommonBlock = LastCommonAncestor(
         state->pindexLastCommonBlock, state->pindexBestKnownBlock);
     if (state->pindexLastCommonBlock == state->pindexBestKnownBlock) {
         return;
     }
 
     std::vector<const CBlockIndex *> vToFetch;
     const CBlockIndex *pindexWalk = state->pindexLastCommonBlock;
     // Never fetch further than the best block we know the peer has, or more
     // than BLOCK_DOWNLOAD_WINDOW + 1 beyond the last linked block we have in
     // common with this peer. The +1 is so we can detect stalling, namely if we
     // would be able to download that next block if the window were 1 larger.
     int nWindowEnd =
         state->pindexLastCommonBlock->nHeight + BLOCK_DOWNLOAD_WINDOW;
     int nMaxHeight =
         std::min<int>(state->pindexBestKnownBlock->nHeight, nWindowEnd + 1);
     NodeId waitingfor = -1;
     while (pindexWalk->nHeight < nMaxHeight) {
         // Read up to 128 (or more, if more blocks than that are needed)
         // successors of pindexWalk (towards pindexBestKnownBlock) into
         // vToFetch. We fetch 128, because CBlockIndex::GetAncestor may be as
         // expensive as iterating over ~100 CBlockIndex* entries anyway.
         int nToFetch = std::min(nMaxHeight - pindexWalk->nHeight,
                                 std::max<int>(count - vBlocks.size(), 128));
         vToFetch.resize(nToFetch);
         pindexWalk = state->pindexBestKnownBlock->GetAncestor(
             pindexWalk->nHeight + nToFetch);
         vToFetch[nToFetch - 1] = pindexWalk;
         for (unsigned int i = nToFetch - 1; i > 0; i--) {
             vToFetch[i - 1] = vToFetch[i]->pprev;
         }
 
         // Iterate over those blocks in vToFetch (in forward direction), adding
         // the ones that are not yet downloaded and not in flight to vBlocks. In
         // the mean time, update pindexLastCommonBlock as long as all ancestors
         // are already downloaded, or if it's already part of our chain (and
         // therefore don't need it even if pruned).
         for (const CBlockIndex *pindex : vToFetch) {
             if (!pindex->IsValid(BLOCK_VALID_TREE)) {
                 // We consider the chain that this peer is on invalid.
                 return;
             }
             if (pindex->nStatus & BLOCK_HAVE_DATA ||
                 chainActive.Contains(pindex)) {
                 if (pindex->nChainTx) {
                     state->pindexLastCommonBlock = pindex;
                 }
             } else if (mapBlocksInFlight.count(pindex->GetBlockHash()) == 0) {
                 // The block is not already downloaded, and not yet in flight.
                 if (pindex->nHeight > nWindowEnd) {
                     // We reached the end of the window.
                     if (vBlocks.size() == 0 && waitingfor != nodeid) {
                         // We aren't able to fetch anything, but we would be if
                         // the download window was one larger.
                         nodeStaller = waitingfor;
                     }
                     return;
                 }
                 vBlocks.push_back(pindex);
                 if (vBlocks.size() == count) {
                     return;
                 }
             } else if (waitingfor == -1) {
                 // This is the first already-in-flight block.
                 waitingfor = mapBlocksInFlight[pindex->GetBlockHash()].first;
             }
         }
     }
 }
 
 } // namespace
 
 bool GetNodeStateStats(NodeId nodeid, CNodeStateStats &stats) {
     LOCK(cs_main);
     CNodeState *state = State(nodeid);
     if (state == nullptr) {
         return false;
     }
     stats.nMisbehavior = state->nMisbehavior;
     stats.nSyncHeight =
         state->pindexBestKnownBlock ? state->pindexBestKnownBlock->nHeight : -1;
     stats.nCommonHeight = state->pindexLastCommonBlock
                               ? state->pindexLastCommonBlock->nHeight
                               : -1;
     for (const QueuedBlock &queue : state->vBlocksInFlight) {
         if (queue.pindex) {
             stats.vHeightInFlight.push_back(queue.pindex->nHeight);
         }
     }
     return true;
 }
 
 void RegisterNodeSignals(CNodeSignals &nodeSignals) {
     nodeSignals.ProcessMessages.connect(&ProcessMessages);
     nodeSignals.SendMessages.connect(&SendMessages);
     nodeSignals.InitializeNode.connect(&InitializeNode);
     nodeSignals.FinalizeNode.connect(&FinalizeNode);
 }
 
 void UnregisterNodeSignals(CNodeSignals &nodeSignals) {
     nodeSignals.ProcessMessages.disconnect(&ProcessMessages);
     nodeSignals.SendMessages.disconnect(&SendMessages);
     nodeSignals.InitializeNode.disconnect(&InitializeNode);
     nodeSignals.FinalizeNode.disconnect(&FinalizeNode);
 }
 
 //////////////////////////////////////////////////////////////////////////////
 //
 // mapOrphanTransactions
 //
 
 void AddToCompactExtraTransactions(const CTransactionRef &tx) {
     size_t max_extra_txn = gArgs.GetArg("-blockreconstructionextratxn",
                                         DEFAULT_BLOCK_RECONSTRUCTION_EXTRA_TXN);
     if (max_extra_txn <= 0) {
         return;
     }
 
     if (!vExtraTxnForCompact.size()) {
         vExtraTxnForCompact.resize(max_extra_txn);
     }
 
     vExtraTxnForCompact[vExtraTxnForCompactIt] =
         std::make_pair(tx->GetId(), tx);
     vExtraTxnForCompactIt = (vExtraTxnForCompactIt + 1) % max_extra_txn;
 }
 
 bool AddOrphanTx(const CTransactionRef &tx, NodeId peer)
     EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
     const uint256 &txid = tx->GetId();
     if (mapOrphanTransactions.count(txid)) {
         return false;
     }
 
     // Ignore big transactions, to avoid a send-big-orphans memory exhaustion
     // attack. If a peer has a legitimate large transaction with a missing
     // parent then we assume it will rebroadcast it later, after the parent
     // transaction(s) have been mined or received.
     // 100 orphans, each of which is at most 99,999 bytes big is at most 10
     // megabytes of orphans and somewhat more byprev index (in the worst case):
     unsigned int sz = tx->GetTotalSize();
     if (sz >= MAX_STANDARD_TX_SIZE) {
         LogPrint(BCLog::MEMPOOL,
                  "ignoring large orphan tx (size: %u, hash: %s)\n", sz,
                  txid.ToString());
         return false;
     }
 
     auto ret = mapOrphanTransactions.emplace(
         txid, COrphanTx{tx, peer, GetTime() + ORPHAN_TX_EXPIRE_TIME});
     assert(ret.second);
     for (const CTxIn &txin : tx->vin) {
         mapOrphanTransactionsByPrev[txin.prevout].insert(ret.first);
     }
 
     AddToCompactExtraTransactions(tx);
 
     LogPrint(BCLog::MEMPOOL, "stored orphan tx %s (mapsz %u outsz %u)\n",
              txid.ToString(), mapOrphanTransactions.size(),
              mapOrphanTransactionsByPrev.size());
     return true;
 }
 
 static int EraseOrphanTx(uint256 hash) EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
     std::map<uint256, COrphanTx>::iterator it =
         mapOrphanTransactions.find(hash);
     if (it == mapOrphanTransactions.end()) {
         return 0;
     }
     for (const CTxIn &txin : it->second.tx->vin) {
         auto itPrev = mapOrphanTransactionsByPrev.find(txin.prevout);
         if (itPrev == mapOrphanTransactionsByPrev.end()) {
             continue;
         }
         itPrev->second.erase(it);
         if (itPrev->second.empty()) {
             mapOrphanTransactionsByPrev.erase(itPrev);
         }
     }
     mapOrphanTransactions.erase(it);
     return 1;
 }
 
 void EraseOrphansFor(NodeId peer) {
     int nErased = 0;
     std::map<uint256, COrphanTx>::iterator iter = mapOrphanTransactions.begin();
     while (iter != mapOrphanTransactions.end()) {
         // Increment to avoid iterator becoming invalid.
         std::map<uint256, COrphanTx>::iterator maybeErase = iter++;
         if (maybeErase->second.fromPeer == peer) {
             nErased += EraseOrphanTx(maybeErase->second.tx->GetId());
         }
     }
     if (nErased > 0) {
         LogPrint(BCLog::MEMPOOL, "Erased %d orphan tx from peer=%d\n", nErased,
                  peer);
     }
 }
 
 unsigned int LimitOrphanTxSize(unsigned int nMaxOrphans)
     EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
     unsigned int nEvicted = 0;
     static int64_t nNextSweep;
     int64_t nNow = GetTime();
     if (nNextSweep <= nNow) {
         // Sweep out expired orphan pool entries:
         int nErased = 0;
         int64_t nMinExpTime =
             nNow + ORPHAN_TX_EXPIRE_TIME - ORPHAN_TX_EXPIRE_INTERVAL;
         std::map<uint256, COrphanTx>::iterator iter =
             mapOrphanTransactions.begin();
         while (iter != mapOrphanTransactions.end()) {
             std::map<uint256, COrphanTx>::iterator maybeErase = iter++;
             if (maybeErase->second.nTimeExpire <= nNow) {
                 nErased += EraseOrphanTx(maybeErase->second.tx->GetId());
             } else {
                 nMinExpTime =
                     std::min(maybeErase->second.nTimeExpire, nMinExpTime);
             }
         }
         // Sweep again 5 minutes after the next entry that expires in order to
         // batch the linear scan.
         nNextSweep = nMinExpTime + ORPHAN_TX_EXPIRE_INTERVAL;
         if (nErased > 0) {
             LogPrint(BCLog::MEMPOOL, "Erased %d orphan tx due to expiration\n",
                      nErased);
         }
     }
     while (mapOrphanTransactions.size() > nMaxOrphans) {
         // Evict a random orphan:
         uint256 randomhash = GetRandHash();
         std::map<uint256, COrphanTx>::iterator it =
             mapOrphanTransactions.lower_bound(randomhash);
         if (it == mapOrphanTransactions.end()) {
             it = mapOrphanTransactions.begin();
         }
         EraseOrphanTx(it->first);
         ++nEvicted;
     }
     return nEvicted;
 }
 
 // Requires cs_main.
 void Misbehaving(NodeId pnode, int howmuch, const std::string &reason) {
     if (howmuch == 0) {
         return;
     }
 
     CNodeState *state = State(pnode);
     if (state == nullptr) {
         return;
     }
 
     state->nMisbehavior += howmuch;
     int banscore = gArgs.GetArg("-banscore", DEFAULT_BANSCORE_THRESHOLD);
     if (state->nMisbehavior >= banscore &&
         state->nMisbehavior - howmuch < banscore) {
         LogPrintf(
             "%s: %s peer=%d (%d -> %d) reason: %s BAN THRESHOLD EXCEEDED\n",
             __func__, state->name, pnode, state->nMisbehavior - howmuch,
             state->nMisbehavior, reason.c_str());
         state->fShouldBan = true;
     } else {
         LogPrintf("%s: %s peer=%d (%d -> %d) reason: %s\n", __func__,
                   state->name, pnode, state->nMisbehavior - howmuch,
                   state->nMisbehavior, reason.c_str());
     }
 }
 
 // overloaded variant of above to operate on CNode*s
 static void Misbehaving(CNode *node, int howmuch, const std::string &reason) {
     Misbehaving(node->GetId(), howmuch, reason);
 }
 
 //////////////////////////////////////////////////////////////////////////////
 //
 // blockchain -> download logic notification
 //
 
 PeerLogicValidation::PeerLogicValidation(CConnman *connmanIn)
     : connman(connmanIn) {
     // Initialize global variables that cannot be constructed at startup.
     recentRejects.reset(new CRollingBloomFilter(120000, 0.000001));
 }
 
 void PeerLogicValidation::BlockConnected(
     const std::shared_ptr<const CBlock> &pblock, const CBlockIndex *pindex,
     const std::vector<CTransactionRef> &vtxConflicted) {
     LOCK(cs_main);
 
     std::vector<uint256> vOrphanErase;
 
     for (const CTransactionRef &ptx : pblock->vtx) {
         const CTransaction &tx = *ptx;
 
         // Which orphan pool entries must we evict?
         for (size_t j = 0; j < tx.vin.size(); j++) {
             auto itByPrev = mapOrphanTransactionsByPrev.find(tx.vin[j].prevout);
             if (itByPrev == mapOrphanTransactionsByPrev.end()) {
                 continue;
             }
 
             for (auto mi = itByPrev->second.begin();
                  mi != itByPrev->second.end(); ++mi) {
                 const CTransaction &orphanTx = *(*mi)->second.tx;
                 const uint256 &orphanHash = orphanTx.GetHash();
                 vOrphanErase.push_back(orphanHash);
             }
         }
     }
 
     // Erase orphan transactions include or precluded by this block
     if (vOrphanErase.size()) {
         int nErased = 0;
         for (uint256 &orphanId : vOrphanErase) {
             nErased += EraseOrphanTx(orphanId);
         }
         LogPrint(BCLog::MEMPOOL,
                  "Erased %d orphan tx included or conflicted by block\n",
                  nErased);
     }
 }
 
 static CCriticalSection cs_most_recent_block;
 static std::shared_ptr<const CBlock> most_recent_block;
 static std::shared_ptr<const CBlockHeaderAndShortTxIDs>
     most_recent_compact_block;
 static uint256 most_recent_block_hash;
 
 void PeerLogicValidation::NewPoWValidBlock(
     const CBlockIndex *pindex, const std::shared_ptr<const CBlock> &pblock) {
     std::shared_ptr<const CBlockHeaderAndShortTxIDs> pcmpctblock =
         std::make_shared<const CBlockHeaderAndShortTxIDs>(*pblock);
     const CNetMsgMaker msgMaker(PROTOCOL_VERSION);
 
     LOCK(cs_main);
 
     static int nHighestFastAnnounce = 0;
     if (pindex->nHeight <= nHighestFastAnnounce) {
         return;
     }
     nHighestFastAnnounce = pindex->nHeight;
 
     uint256 hashBlock(pblock->GetHash());
 
     {
         LOCK(cs_most_recent_block);
         most_recent_block_hash = hashBlock;
         most_recent_block = pblock;
         most_recent_compact_block = pcmpctblock;
     }
 
     connman->ForEachNode([this, &pcmpctblock, pindex, &msgMaker,
                           &hashBlock](CNode *pnode) {
         // TODO: Avoid the repeated-serialization here
         if (pnode->nVersion < INVALID_CB_NO_BAN_VERSION || pnode->fDisconnect) {
             return;
         }
         ProcessBlockAvailability(pnode->GetId());
         CNodeState &state = *State(pnode->GetId());
         // If the peer has, or we announced to them the previous block already,
         // but we don't think they have this one, go ahead and announce it.
         if (state.fPreferHeaderAndIDs && !PeerHasHeader(&state, pindex) &&
             PeerHasHeader(&state, pindex->pprev)) {
 
             LogPrint(BCLog::NET, "%s sending header-and-ids %s to peer=%d\n",
                      "PeerLogicValidation::NewPoWValidBlock",
                      hashBlock.ToString(), pnode->id);
             connman->PushMessage(
                 pnode, msgMaker.Make(NetMsgType::CMPCTBLOCK, *pcmpctblock));
             state.pindexBestHeaderSent = pindex;
         }
     });
 }
 
 void PeerLogicValidation::UpdatedBlockTip(const CBlockIndex *pindexNew,
                                           const CBlockIndex *pindexFork,
                                           bool fInitialDownload) {
     const int nNewHeight = pindexNew->nHeight;
     connman->SetBestHeight(nNewHeight);
 
     if (!fInitialDownload) {
         // Find the hashes of all blocks that weren't previously in the best
         // chain.
         std::vector<uint256> vHashes;
         const CBlockIndex *pindexToAnnounce = pindexNew;
         while (pindexToAnnounce != pindexFork) {
             vHashes.push_back(pindexToAnnounce->GetBlockHash());
             pindexToAnnounce = pindexToAnnounce->pprev;
             if (vHashes.size() == MAX_BLOCKS_TO_ANNOUNCE) {
                 // Limit announcements in case of a huge reorganization. Rely on
                 // the peer's synchronization mechanism in that case.
                 break;
             }
         }
         // Relay inventory, but don't relay old inventory during initial block
         // download.
         connman->ForEachNode([nNewHeight, &vHashes](CNode *pnode) {
             if (nNewHeight > (pnode->nStartingHeight != -1
                                   ? pnode->nStartingHeight - 2000
                                   : 0)) {
                 for (const uint256 &hash : boost::adaptors::reverse(vHashes)) {
                     pnode->PushBlockHash(hash);
                 }
             }
         });
         connman->WakeMessageHandler();
     }
 
     nTimeBestReceived = GetTime();
 }
 
 void PeerLogicValidation::BlockChecked(const CBlock &block,
                                        const CValidationState &state) {
     LOCK(cs_main);
 
     const uint256 hash(block.GetHash());
     std::map<uint256, std::pair<NodeId, bool>>::iterator it =
         mapBlockSource.find(hash);
 
     int nDoS = 0;
     if (state.IsInvalid(nDoS)) {
         // Don't send reject message with code 0 or an internal reject code.
         if (it != mapBlockSource.end() && State(it->second.first) &&
             state.GetRejectCode() > 0 &&
             state.GetRejectCode() < REJECT_INTERNAL) {
             CBlockReject reject = {
                 uint8_t(state.GetRejectCode()),
                 state.GetRejectReason().substr(0, MAX_REJECT_MESSAGE_LENGTH),
                 hash};
             State(it->second.first)->rejects.push_back(reject);
             if (nDoS > 0 && it->second.second) {
                 Misbehaving(it->second.first, nDoS, state.GetRejectReason());
             }
         }
     }
     // Check that:
     // 1. The block is valid
     // 2. We're not in initial block download
     // 3. This is currently the best block we're aware of. We haven't updated
     //    the tip yet so we have no way to check this directly here. Instead we
     //    just check that there are currently no other blocks in flight.
     else if (state.IsValid() && !IsInitialBlockDownload() &&
              mapBlocksInFlight.count(hash) == mapBlocksInFlight.size()) {
         if (it != mapBlockSource.end()) {
             MaybeSetPeerAsAnnouncingHeaderAndIDs(it->second.first, *connman);
         }
     }
 
     if (it != mapBlockSource.end()) {
         mapBlockSource.erase(it);
     }
 }
 
 //////////////////////////////////////////////////////////////////////////////
 //
 // Messages
 //
 
 static bool AlreadyHave(const CInv &inv) EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
     switch (inv.type) {
         case MSG_TX: {
             assert(recentRejects);
             if (chainActive.Tip()->GetBlockHash() !=
                 hashRecentRejectsChainTip) {
                 // If the chain tip has changed previously rejected transactions
                 // might be now valid, e.g. due to a nLockTime'd tx becoming
                 // valid, or a double-spend. Reset the rejects filter and give
                 // those txs a second chance.
                 hashRecentRejectsChainTip = chainActive.Tip()->GetBlockHash();
                 recentRejects->reset();
             }
 
             // Use pcoinsTip->HaveCoinInCache as a quick approximation to
             // exclude requesting or processing some txs which have already been
             // included in a block. As this is best effort, we only check for
             // output 0 and 1. This works well enough in practice and we get
             // diminishing returns with 2 onward.
             return recentRejects->contains(inv.hash) ||
                    mempool.exists(inv.hash) ||
                    mapOrphanTransactions.count(inv.hash) ||
                    pcoinsTip->HaveCoinInCache(COutPoint(inv.hash, 0)) ||
                    pcoinsTip->HaveCoinInCache(COutPoint(inv.hash, 1));
         }
         case MSG_BLOCK:
             return mapBlockIndex.count(inv.hash);
     }
     // Don't know what it is, just say we already got one
     return true;
 }
 
 static void RelayTransaction(const CTransaction &tx, CConnman &connman) {
     CInv inv(MSG_TX, tx.GetId());
     connman.ForEachNode([&inv](CNode *pnode) { pnode->PushInventory(inv); });
 }
 
 static void RelayAddress(const CAddress &addr, bool fReachable,
                          CConnman &connman) {
     // Limited relaying of addresses outside our network(s)
     unsigned int nRelayNodes = fReachable ? 2 : 1;
 
     // Relay to a limited number of other nodes.
     // Use deterministic randomness to send to the same nodes for 24 hours at a
     // time so the addrKnowns of the chosen nodes prevent repeats.
     uint64_t hashAddr = addr.GetHash();
     const CSipHasher hasher =
         connman.GetDeterministicRandomizer(RANDOMIZER_ID_ADDRESS_RELAY)
             .Write(hashAddr << 32)
             .Write((GetTime() + hashAddr) / (24 * 60 * 60));
     FastRandomContext insecure_rand;
 
     std::array<std::pair<uint64_t, CNode *>, 2> best{
         {{0, nullptr}, {0, nullptr}}};
     assert(nRelayNodes <= best.size());
 
     auto sortfunc = [&best, &hasher, nRelayNodes](CNode *pnode) {
         if (pnode->nVersion >= CADDR_TIME_VERSION) {
             uint64_t hashKey = CSipHasher(hasher).Write(pnode->id).Finalize();
             for (unsigned int i = 0; i < nRelayNodes; i++) {
                 if (hashKey > best[i].first) {
                     std::copy(best.begin() + i, best.begin() + nRelayNodes - 1,
                               best.begin() + i + 1);
                     best[i] = std::make_pair(hashKey, pnode);
                     break;
                 }
             }
         }
     };
 
     auto pushfunc = [&addr, &best, nRelayNodes, &insecure_rand] {
         for (unsigned int i = 0; i < nRelayNodes && best[i].first != 0; i++) {
             best[i].second->PushAddress(addr, insecure_rand);
         }
     };
 
     connman.ForEachNodeThen(std::move(sortfunc), std::move(pushfunc));
 }
 
 static void ProcessGetData(const Config &config, CNode *pfrom,
                            const Consensus::Params &consensusParams,
                            CConnman &connman,
                            const std::atomic<bool> &interruptMsgProc) {
     std::deque<CInv>::iterator it = pfrom->vRecvGetData.begin();
     std::vector<CInv> vNotFound;
     const CNetMsgMaker msgMaker(pfrom->GetSendVersion());
     LOCK(cs_main);
 
     while (it != pfrom->vRecvGetData.end()) {
         // Don't bother if send buffer is too full to respond anyway.
         if (pfrom->fPauseSend) {
             break;
         }
 
         const CInv &inv = *it;
         {
             if (interruptMsgProc) {
                 return;
             }
 
             it++;
 
             if (inv.type == MSG_BLOCK || inv.type == MSG_FILTERED_BLOCK ||
                 inv.type == MSG_CMPCT_BLOCK) {
                 bool send = false;
                 BlockMap::iterator mi = mapBlockIndex.find(inv.hash);
                 if (mi != mapBlockIndex.end()) {
                     if (mi->second->nChainTx &&
                         !mi->second->IsValid(BLOCK_VALID_SCRIPTS) &&
                         mi->second->IsValid(BLOCK_VALID_TREE)) {
                         // If we have the block and all of its parents, but have
                         // not yet validated it, we might be in the middle of
                         // connecting it (ie in the unlock of cs_main before
                         // ActivateBestChain but after AcceptBlock). In this
                         // case, we need to run ActivateBestChain prior to
                         // checking the relay conditions below.
                         std::shared_ptr<const CBlock> a_recent_block;
                         {
                             LOCK(cs_most_recent_block);
                             a_recent_block = most_recent_block;
                         }
                         CValidationState dummy;
                         ActivateBestChain(config, dummy, a_recent_block);
                     }
                     if (chainActive.Contains(mi->second)) {
                         send = true;
                     } else {
                         static const int nOneMonth = 30 * 24 * 60 * 60;
                         // To prevent fingerprinting attacks, only send blocks
                         // outside of the active chain if they are valid, and no
                         // more than a month older (both in time, and in best
                         // equivalent proof of work) than the best header chain
                         // we know about.
                         send = mi->second->IsValid(BLOCK_VALID_SCRIPTS) &&
                                (pindexBestHeader != nullptr) &&
                                (pindexBestHeader->GetBlockTime() -
                                     mi->second->GetBlockTime() <
                                 nOneMonth) &&
                                (GetBlockProofEquivalentTime(
                                     *pindexBestHeader, *mi->second,
                                     *pindexBestHeader,
                                     consensusParams) < nOneMonth);
                         if (!send) {
                             LogPrintf("%s: ignoring request from peer=%i for "
                                       "old block that isn't in the main "
                                       "chain\n",
                                       __func__, pfrom->GetId());
                         }
                     }
                 }
 
                 // Disconnect node in case we have reached the outbound limit
                 // for serving historical blocks never disconnect whitelisted
                 // nodes.
                 // assume > 1 week = historical
                 static const int nOneWeek = 7 * 24 * 60 * 60;
                 if (send && connman.OutboundTargetReached(true) &&
                     (((pindexBestHeader != nullptr) &&
                       (pindexBestHeader->GetBlockTime() -
                            mi->second->GetBlockTime() >
                        nOneWeek)) ||
                      inv.type == MSG_FILTERED_BLOCK) &&
                     !pfrom->fWhitelisted) {
                     LogPrint(BCLog::NET, "historical block serving limit "
                                          "reached, disconnect peer=%d\n",
                              pfrom->GetId());
 
                     // disconnect node
                     pfrom->fDisconnect = true;
                     send = false;
                 }
                 // Pruned nodes may have deleted the block, so check whether
                 // it's available before trying to send.
                 if (send && (mi->second->nStatus & BLOCK_HAVE_DATA)) {
                     // Send block from disk
                     CBlock block;
                     if (!ReadBlockFromDisk(block, (*mi).second, config)) {
                         assert(!"cannot load block from disk");
                     }
 
                     if (inv.type == MSG_BLOCK) {
                         connman.PushMessage(
                             pfrom, msgMaker.Make(NetMsgType::BLOCK, block));
                     } else if (inv.type == MSG_FILTERED_BLOCK) {
                         bool sendMerkleBlock = false;
                         CMerkleBlock merkleBlock;
                         {
                             LOCK(pfrom->cs_filter);
                             if (pfrom->pfilter) {
                                 sendMerkleBlock = true;
                                 merkleBlock =
                                     CMerkleBlock(block, *pfrom->pfilter);
                             }
                         }
                         if (sendMerkleBlock) {
                             connman.PushMessage(
                                 pfrom,
                                 msgMaker.Make(NetMsgType::MERKLEBLOCK,
                                               merkleBlock));
                             // CMerkleBlock just contains hashes, so also push
                             // any transactions in the block the client did not
                             // see. This avoids hurting performance by
                             // pointlessly requiring a round-trip. Note that
                             // there is currently no way for a node to request
                             // any single transactions we didn't send here -
                             // they must either disconnect and retry or request
                             // the full block. Thus, the protocol spec specified
                             // allows for us to provide duplicate txn here,
                             // however we MUST always provide at least what the
                             // remote peer needs.
                             typedef std::pair<unsigned int, uint256> PairType;
                             for (PairType &pair : merkleBlock.vMatchedTxn) {
                                 connman.PushMessage(
                                     pfrom,
                                     msgMaker.Make(NetMsgType::TX,
                                                   *block.vtx[pair.first]));
                             }
                         }
                         // else
                         // no response
                     } else if (inv.type == MSG_CMPCT_BLOCK) {
                         // If a peer is asking for old blocks, we're almost
                         // guaranteed they won't have a useful mempool to match
                         // against a compact block, and we don't feel like
                         // constructing the object for them, so instead we
                         // respond with the full, non-compact block.
                         int nSendFlags = 0;
                         if (CanDirectFetch(consensusParams) &&
                             mi->second->nHeight >=
                                 chainActive.Height() - MAX_CMPCTBLOCK_DEPTH) {
                             CBlockHeaderAndShortTxIDs cmpctblock(block);
                             connman.PushMessage(
                                 pfrom,
                                 msgMaker.Make(nSendFlags,
                                               NetMsgType::CMPCTBLOCK,
                                               cmpctblock));
                         } else {
                             connman.PushMessage(pfrom,
                                                 msgMaker.Make(nSendFlags,
                                                               NetMsgType::BLOCK,
                                                               block));
                         }
                     }
 
                     // Trigger the peer node to send a getblocks request for the
                     // next batch of inventory.
                     if (inv.hash == pfrom->hashContinue) {
                         // Bypass PushInventory, this must send even if
                         // redundant, and we want it right after the last block
                         // so they don't wait for other stuff first.
                         std::vector<CInv> vInv;
                         vInv.push_back(
                             CInv(MSG_BLOCK, chainActive.Tip()->GetBlockHash()));
                         connman.PushMessage(
                             pfrom, msgMaker.Make(NetMsgType::INV, vInv));
                         pfrom->hashContinue.SetNull();
                     }
                 }
             } else if (inv.type == MSG_TX) {
                 // Send stream from relay memory
                 bool push = false;
                 auto mi = mapRelay.find(inv.hash);
                 int nSendFlags = 0;
                 if (mi != mapRelay.end()) {
                     connman.PushMessage(
                         pfrom,
                         msgMaker.Make(nSendFlags, NetMsgType::TX, *mi->second));
                     push = true;
                 } else if (pfrom->timeLastMempoolReq) {
                     auto txinfo = mempool.info(inv.hash);
                     // To protect privacy, do not answer getdata using the
                     // mempool when that TX couldn't have been INVed in reply to
                     // a MEMPOOL request.
                     if (txinfo.tx &&
                         txinfo.nTime <= pfrom->timeLastMempoolReq) {
                         connman.PushMessage(pfrom,
                                             msgMaker.Make(nSendFlags,
                                                           NetMsgType::TX,
                                                           *txinfo.tx));
                         push = true;
                     }
                 }
                 if (!push) {
                     vNotFound.push_back(inv);
                 }
             }
 
             // Track requests for our stuff.
             GetMainSignals().Inventory(inv.hash);
 
             if (inv.type == MSG_BLOCK || inv.type == MSG_FILTERED_BLOCK ||
                 inv.type == MSG_CMPCT_BLOCK) {
                 break;
             }
         }
     }
 
     pfrom->vRecvGetData.erase(pfrom->vRecvGetData.begin(), it);
 
     if (!vNotFound.empty()) {
         // Let the peer know that we didn't find what it asked for, so it
         // doesn't have to wait around forever. Currently only SPV clients
         // actually care about this message: it's needed when they are
         // recursively walking the dependencies of relevant unconfirmed
         // transactions. SPV clients want to do that because they want to know
         // about (and store and rebroadcast and risk analyze) the dependencies
         // of transactions relevant to them, without having to download the
         // entire memory pool.
         connman.PushMessage(pfrom,
                             msgMaker.Make(NetMsgType::NOTFOUND, vNotFound));
     }
 }
 
 uint32_t GetFetchFlags(CNode *pfrom, const CBlockIndex *pprev,
                        const Consensus::Params &chainparams) {
     uint32_t nFetchFlags = 0;
     return nFetchFlags;
 }
 
 inline static void SendBlockTransactions(const CBlock &block,
                                          const BlockTransactionsRequest &req,
                                          CNode *pfrom, CConnman &connman) {
     BlockTransactions resp(req);
     for (size_t i = 0; i < req.indices.size(); i++) {
         if (req.indices[i] >= block.vtx.size()) {
             LOCK(cs_main);
             Misbehaving(pfrom, 100, "out-of-bound-tx-index");
             LogPrintf(
                 "Peer %d sent us a getblocktxn with out-of-bounds tx indices",
                 pfrom->id);
             return;
         }
         resp.txn[i] = block.vtx[req.indices[i]];
     }
     LOCK(cs_main);
     const CNetMsgMaker msgMaker(pfrom->GetSendVersion());
     int nSendFlags = 0;
     connman.PushMessage(pfrom,
                         msgMaker.Make(nSendFlags, NetMsgType::BLOCKTXN, resp));
 }
 
 static bool ProcessMessage(const Config &config, CNode *pfrom,
                            const std::string &strCommand, CDataStream &vRecv,
                            int64_t nTimeReceived,
                            const CChainParams &chainparams, CConnman &connman,
                            const std::atomic<bool> &interruptMsgProc) {
     LogPrint(BCLog::NET, "received: %s (%u bytes) peer=%d\n",
              SanitizeString(strCommand), vRecv.size(), pfrom->id);
     if (gArgs.IsArgSet("-dropmessagestest") &&
         GetRand(gArgs.GetArg("-dropmessagestest", 0)) == 0) {
         LogPrintf("dropmessagestest DROPPING RECV MESSAGE\n");
         return true;
     }
 
     if (!(pfrom->GetLocalServices() & NODE_BLOOM) &&
         (strCommand == NetMsgType::FILTERLOAD ||
          strCommand == NetMsgType::FILTERADD)) {
         if (pfrom->nVersion >= NO_BLOOM_VERSION) {
             LOCK(cs_main);
             Misbehaving(pfrom, 100, "no-bloom-version");
             return false;
         } else {
             pfrom->fDisconnect = true;
             return false;
         }
     }
 
     if (strCommand == NetMsgType::REJECT) {
         if (LogAcceptCategory(BCLog::NET)) {
             try {
                 std::string strMsg;
                 uint8_t ccode;
                 std::string strReason;
                 vRecv >> LIMITED_STRING(strMsg, CMessageHeader::COMMAND_SIZE) >>
                     ccode >>
                     LIMITED_STRING(strReason, MAX_REJECT_MESSAGE_LENGTH);
 
                 std::ostringstream ss;
                 ss << strMsg << " code " << itostr(ccode) << ": " << strReason;
 
                 if (strMsg == NetMsgType::BLOCK || strMsg == NetMsgType::TX) {
                     uint256 hash;
                     vRecv >> hash;
                     ss << ": hash " << hash.ToString();
                 }
                 LogPrint(BCLog::NET, "Reject %s\n", SanitizeString(ss.str()));
             } catch (const std::ios_base::failure &) {
                 // Avoid feedback loops by preventing reject messages from
                 // triggering a new reject message.
                 LogPrint(BCLog::NET, "Unparseable reject message received\n");
             }
         }
     }
 
     else if (strCommand == NetMsgType::VERSION) {
         // Each connection can only send one version message
         if (pfrom->nVersion != 0) {
             connman.PushMessage(
                 pfrom,
                 CNetMsgMaker(INIT_PROTO_VERSION)
                     .Make(NetMsgType::REJECT, strCommand, REJECT_DUPLICATE,
                           std::string("Duplicate version message")));
             LOCK(cs_main);
             Misbehaving(pfrom, 1, "multiple-version");
             return false;
         }
 
         int64_t nTime;
         CAddress addrMe;
         CAddress addrFrom;
         uint64_t nNonce = 1;
         uint64_t nServiceInt;
         ServiceFlags nServices;
         int nVersion;
         int nSendVersion;
         std::string strSubVer;
         std::string cleanSubVer;
         int nStartingHeight = -1;
         bool fRelay = true;
 
         vRecv >> nVersion >> nServiceInt >> nTime >> addrMe;
         nSendVersion = std::min(nVersion, PROTOCOL_VERSION);
         nServices = ServiceFlags(nServiceInt);
         if (!pfrom->fInbound) {
             connman.SetServices(pfrom->addr, nServices);
         }
         if (pfrom->nServicesExpected & ~nServices) {
             LogPrint(BCLog::NET, "peer=%d does not offer the expected services "
                                  "(%08x offered, %08x expected); "
                                  "disconnecting\n",
                      pfrom->id, nServices, pfrom->nServicesExpected);
             connman.PushMessage(
                 pfrom,
                 CNetMsgMaker(INIT_PROTO_VERSION)
                     .Make(NetMsgType::REJECT, strCommand, REJECT_NONSTANDARD,
                           strprintf("Expected to offer services %08x",
                                     pfrom->nServicesExpected)));
             pfrom->fDisconnect = true;
             return false;
         }
 
         if (nVersion < MIN_PEER_PROTO_VERSION) {
             // disconnect from peers older than this proto version
             LogPrintf("peer=%d using obsolete version %i; disconnecting\n",
                       pfrom->id, nVersion);
             connman.PushMessage(
                 pfrom,
                 CNetMsgMaker(INIT_PROTO_VERSION)
                     .Make(NetMsgType::REJECT, strCommand, REJECT_OBSOLETE,
                           strprintf("Version must be %d or greater",
                                     MIN_PEER_PROTO_VERSION)));
             pfrom->fDisconnect = true;
             return false;
         }
 
         if (!vRecv.empty()) {
             vRecv >> addrFrom >> nNonce;
         }
         if (!vRecv.empty()) {
             vRecv >> LIMITED_STRING(strSubVer, MAX_SUBVERSION_LENGTH);
             cleanSubVer = SanitizeString(strSubVer);
         }
         if (!vRecv.empty()) {
             vRecv >> nStartingHeight;
         }
         if (!vRecv.empty()) {
             vRecv >> fRelay;
         }
         // Disconnect if we connected to ourself
         if (pfrom->fInbound && !connman.CheckIncomingNonce(nNonce)) {
             LogPrintf("connected to self at %s, disconnecting\n",
                       pfrom->addr.ToString());
             pfrom->fDisconnect = true;
             return true;
         }
 
         if (pfrom->fInbound && addrMe.IsRoutable()) {
             SeenLocal(addrMe);
         }
 
         // Be shy and don't send version until we hear
         if (pfrom->fInbound) {
             PushNodeVersion(config, pfrom, connman, GetAdjustedTime());
         }
 
         connman.PushMessage(
             pfrom, CNetMsgMaker(INIT_PROTO_VERSION).Make(NetMsgType::VERACK));
 
         pfrom->nServices = nServices;
         pfrom->SetAddrLocal(addrMe);
         {
             LOCK(pfrom->cs_SubVer);
             pfrom->strSubVer = strSubVer;
             pfrom->cleanSubVer = cleanSubVer;
         }
         pfrom->nStartingHeight = nStartingHeight;
         pfrom->fClient = !(nServices & NODE_NETWORK);
         {
             LOCK(pfrom->cs_filter);
             // set to true after we get the first filter* message
             pfrom->fRelayTxes = fRelay;
         }
 
         // Change version
         pfrom->SetSendVersion(nSendVersion);
         pfrom->nVersion = nVersion;
 
         // Potentially mark this peer as a preferred download peer.
         {
             LOCK(cs_main);
             UpdatePreferredDownload(pfrom, State(pfrom->GetId()));
         }
 
         if (!pfrom->fInbound) {
             // Advertise our address
             if (fListen && !IsInitialBlockDownload()) {
                 CAddress addr =
                     GetLocalAddress(&pfrom->addr, pfrom->GetLocalServices());
                 FastRandomContext insecure_rand;
                 if (addr.IsRoutable()) {
                     LogPrint(BCLog::NET,
                              "ProcessMessages: advertising address %s\n",
                              addr.ToString());
                     pfrom->PushAddress(addr, insecure_rand);
                 } else if (IsPeerAddrLocalGood(pfrom)) {
                     addr.SetIP(addrMe);
                     LogPrint(BCLog::NET,
                              "ProcessMessages: advertising address %s\n",
                              addr.ToString());
                     pfrom->PushAddress(addr, insecure_rand);
                 }
             }
 
             // Get recent addresses
             if (pfrom->fOneShot || pfrom->nVersion >= CADDR_TIME_VERSION ||
                 connman.GetAddressCount() < 1000) {
                 connman.PushMessage(
                     pfrom,
                     CNetMsgMaker(nSendVersion).Make(NetMsgType::GETADDR));
                 pfrom->fGetAddr = true;
             }
             connman.MarkAddressGood(pfrom->addr);
         }
 
         std::string remoteAddr;
         if (fLogIPs) {
             remoteAddr = ", peeraddr=" + pfrom->addr.ToString();
         }
 
         LogPrintf("receive version message: [%s] %s: version %d, blocks=%d, "
                   "us=%s, peer=%d%s\n",
                   pfrom->addr.ToString().c_str(), cleanSubVer, pfrom->nVersion,
                   pfrom->nStartingHeight, addrMe.ToString(), pfrom->id,
                   remoteAddr);
 
         int64_t nTimeOffset = nTime - GetTime();
         pfrom->nTimeOffset = nTimeOffset;
         AddTimeData(pfrom->addr, nTimeOffset);
 
         // If the peer is old enough to have the old alert system, send it the
         // final alert.
         if (pfrom->nVersion <= 70012) {
             CDataStream finalAlert(
                 ParseHex("60010000000000000000000000ffffff7f00000000ffffff7ffef"
                          "fff7f01ffffff7f00000000ffffff7f00ffffff7f002f55524745"
                          "4e543a20416c657274206b657920636f6d70726f6d697365642c2"
                          "075706772616465207265717569726564004630440220653febd6"
                          "410f470f6bae11cad19c48413becb1ac2c17f908fd0fd53bdc3ab"
                          "d5202206d0e9c96fe88d4a0f01ed9dedae2b6f9e00da94cad0fec"
                          "aae66ecf689bf71b50"),
                 SER_NETWORK, PROTOCOL_VERSION);
             connman.PushMessage(
                 pfrom, CNetMsgMaker(nSendVersion).Make("alert", finalAlert));
         }
 
         // Feeler connections exist only to verify if address is online.
         if (pfrom->fFeeler) {
             assert(pfrom->fInbound == false);
             pfrom->fDisconnect = true;
         }
         return true;
     }
 
     else if (pfrom->nVersion == 0) {
         // Must have a version message before anything else
         LOCK(cs_main);
         Misbehaving(pfrom, 1, "missing-version");
         return false;
     }
 
     // At this point, the outgoing message serialization version can't change.
     const CNetMsgMaker msgMaker(pfrom->GetSendVersion());
 
     if (strCommand == NetMsgType::VERACK) {
         pfrom->SetRecvVersion(
             std::min(pfrom->nVersion.load(), PROTOCOL_VERSION));
 
         if (!pfrom->fInbound) {
             // Mark this node as currently connected, so we update its timestamp
             // later.
             LOCK(cs_main);
             State(pfrom->GetId())->fCurrentlyConnected = true;
         }
 
         if (pfrom->nVersion >= SENDHEADERS_VERSION) {
             // Tell our peer we prefer to receive headers rather than inv's
             // We send this to non-NODE NETWORK peers as well, because even
             // non-NODE NETWORK peers can announce blocks (such as pruning
             // nodes)
             connman.PushMessage(pfrom, msgMaker.Make(NetMsgType::SENDHEADERS));
         }
         if (pfrom->nVersion >= SHORT_IDS_BLOCKS_VERSION) {
             // Tell our peer we are willing to provide version 1 or 2
             // cmpctblocks. However, we do not request new block announcements
             // using cmpctblock messages. We send this to non-NODE NETWORK peers
             // as well, because they may wish to request compact blocks from us.
             bool fAnnounceUsingCMPCTBLOCK = false;
             uint64_t nCMPCTBLOCKVersion = 1;
             connman.PushMessage(pfrom,
                                 msgMaker.Make(NetMsgType::SENDCMPCT,
                                               fAnnounceUsingCMPCTBLOCK,
                                               nCMPCTBLOCKVersion));
         }
         pfrom->fSuccessfullyConnected = true;
     }
 
     else if (!pfrom->fSuccessfullyConnected) {
         // Must have a verack message before anything else
         LOCK(cs_main);
         Misbehaving(pfrom, 1, "missing-verack");
         return false;
     }
 
     else if (strCommand == NetMsgType::ADDR) {
         std::vector<CAddress> vAddr;
         vRecv >> vAddr;
 
         // Don't want addr from older versions unless seeding
         if (pfrom->nVersion < CADDR_TIME_VERSION &&
             connman.GetAddressCount() > 1000) {
             return true;
         }
         if (vAddr.size() > 1000) {
             LOCK(cs_main);
             Misbehaving(pfrom, 20, "oversized-addr");
             return error("message addr size() = %u", vAddr.size());
         }
 
         // Store the new addresses
         std::vector<CAddress> vAddrOk;
         int64_t nNow = GetAdjustedTime();
         int64_t nSince = nNow - 10 * 60;
         for (CAddress &addr : vAddr) {
             if (interruptMsgProc) {
                 return true;
             }
 
             if ((addr.nServices & REQUIRED_SERVICES) != REQUIRED_SERVICES) {
                 continue;
             }
 
             if (addr.nTime <= 100000000 || addr.nTime > nNow + 10 * 60) {
                 addr.nTime = nNow - 5 * 24 * 60 * 60;
             }
             pfrom->AddAddressKnown(addr);
             bool fReachable = IsReachable(addr);
             if (addr.nTime > nSince && !pfrom->fGetAddr && vAddr.size() <= 10 &&
                 addr.IsRoutable()) {
                 // Relay to a limited number of other nodes
                 RelayAddress(addr, fReachable, connman);
             }
             // Do not store addresses outside our network
             if (fReachable) {
                 vAddrOk.push_back(addr);
             }
         }
         connman.AddNewAddresses(vAddrOk, pfrom->addr, 2 * 60 * 60);
         if (vAddr.size() < 1000) {
             pfrom->fGetAddr = false;
         }
         if (pfrom->fOneShot) {
             pfrom->fDisconnect = true;
         }
     }
 
     else if (strCommand == NetMsgType::SENDHEADERS) {
         LOCK(cs_main);
         State(pfrom->GetId())->fPreferHeaders = true;
     }
 
     else if (strCommand == NetMsgType::SENDCMPCT) {
         bool fAnnounceUsingCMPCTBLOCK = false;
         uint64_t nCMPCTBLOCKVersion = 0;
         vRecv >> fAnnounceUsingCMPCTBLOCK >> nCMPCTBLOCKVersion;
         if (nCMPCTBLOCKVersion == 1) {
             LOCK(cs_main);
             // fProvidesHeaderAndIDs is used to "lock in" version of compact
             // blocks we send.
             if (!State(pfrom->GetId())->fProvidesHeaderAndIDs) {
                 State(pfrom->GetId())->fProvidesHeaderAndIDs = true;
             }
 
             State(pfrom->GetId())->fPreferHeaderAndIDs =
                 fAnnounceUsingCMPCTBLOCK;
             if (!State(pfrom->GetId())->fSupportsDesiredCmpctVersion) {
                 State(pfrom->GetId())->fSupportsDesiredCmpctVersion = true;
             }
         }
     }
 
     else if (strCommand == NetMsgType::INV) {
         std::vector<CInv> vInv;
         vRecv >> vInv;
         if (vInv.size() > MAX_INV_SZ) {
             LOCK(cs_main);
             Misbehaving(pfrom, 20, "oversized-inv");
             return error("message inv size() = %u", vInv.size());
         }
 
         bool fBlocksOnly = !fRelayTxes;
 
         // Allow whitelisted peers to send data other than blocks in blocks only
         // mode if whitelistrelay is true
         if (pfrom->fWhitelisted &&
             gArgs.GetBoolArg("-whitelistrelay", DEFAULT_WHITELISTRELAY)) {
             fBlocksOnly = false;
         }
 
         LOCK(cs_main);
 
         uint32_t nFetchFlags =
             GetFetchFlags(pfrom, chainActive.Tip(), chainparams.GetConsensus());
 
         std::vector<CInv> vToFetch;
 
         for (size_t nInv = 0; nInv < vInv.size(); nInv++) {
             CInv &inv = vInv[nInv];
 
             if (interruptMsgProc) {
                 return true;
             }
 
             bool fAlreadyHave = AlreadyHave(inv);
             LogPrint(BCLog::NET, "got inv: %s  %s peer=%d\n", inv.ToString(),
                      fAlreadyHave ? "have" : "new", pfrom->id);
 
             if (inv.type == MSG_TX) {
                 inv.type |= nFetchFlags;
             }
 
             if (inv.type == MSG_BLOCK) {
                 UpdateBlockAvailability(pfrom->GetId(), inv.hash);
                 if (!fAlreadyHave && !fImporting && !fReindex &&
                     !mapBlocksInFlight.count(inv.hash)) {
                     // We used to request the full block here, but since
                     // headers-announcements are now the primary method of
                     // announcement on the network, and since, in the case that
                     // a node fell back to inv we probably have a reorg which we
                     // should get the headers for first, we now only provide a
                     // getheaders response here. When we receive the headers, we
                     // will then ask for the blocks we need.
                     connman.PushMessage(
                         pfrom,
                         msgMaker.Make(NetMsgType::GETHEADERS,
                                       chainActive.GetLocator(pindexBestHeader),
                                       inv.hash));
                     LogPrint(BCLog::NET, "getheaders (%d) %s to peer=%d\n",
                              pindexBestHeader->nHeight, inv.hash.ToString(),
                              pfrom->id);
                 }
             } else {
                 pfrom->AddInventoryKnown(inv);
                 if (fBlocksOnly) {
                     LogPrint(BCLog::NET, "transaction (%s) inv sent in "
                                          "violation of protocol peer=%d\n",
                              inv.hash.ToString(), pfrom->id);
                 } else if (!fAlreadyHave && !fImporting && !fReindex &&
                            !IsInitialBlockDownload()) {
                     pfrom->AskFor(inv);
                 }
             }
 
             // Track requests for our stuff
             GetMainSignals().Inventory(inv.hash);
         }
 
         if (!vToFetch.empty()) {
             connman.PushMessage(pfrom,
                                 msgMaker.Make(NetMsgType::GETDATA, vToFetch));
         }
     }
 
     else if (strCommand == NetMsgType::GETDATA) {
         std::vector<CInv> vInv;
         vRecv >> vInv;
         if (vInv.size() > MAX_INV_SZ) {
             LOCK(cs_main);
             Misbehaving(pfrom, 20, "too-many-inv");
             return error("message getdata size() = %u", vInv.size());
         }
 
         LogPrint(BCLog::NET, "received getdata (%u invsz) peer=%d\n",
                  vInv.size(), pfrom->id);
 
         if (vInv.size() > 0) {
             LogPrint(BCLog::NET, "received getdata for: %s peer=%d\n",
                      vInv[0].ToString(), pfrom->id);
         }
 
         pfrom->vRecvGetData.insert(pfrom->vRecvGetData.end(), vInv.begin(),
                                    vInv.end());
         ProcessGetData(config, pfrom, chainparams.GetConsensus(), connman,
                        interruptMsgProc);
     }
 
     else if (strCommand == NetMsgType::GETBLOCKS) {
         CBlockLocator locator;
         uint256 hashStop;
         vRecv >> locator >> hashStop;
 
         // We might have announced the currently-being-connected tip using a
         // compact block, which resulted in the peer sending a getblocks
         // request, which we would otherwise respond to without the new block.
         // To avoid this situation we simply verify that we are on our best
         // known chain now. This is super overkill, but we handle it better
         // for getheaders requests, and there are no known nodes which support
         // compact blocks but still use getblocks to request blocks.
         {
             std::shared_ptr<const CBlock> a_recent_block;
             {
                 LOCK(cs_most_recent_block);
                 a_recent_block = most_recent_block;
             }
             CValidationState dummy;
             ActivateBestChain(config, dummy, a_recent_block);
         }
 
         LOCK(cs_main);
 
         // Find the last block the caller has in the main chain
         const CBlockIndex *pindex = FindForkInGlobalIndex(chainActive, locator);
 
         // Send the rest of the chain
         if (pindex) {
             pindex = chainActive.Next(pindex);
         }
         int nLimit = 500;
         LogPrint(BCLog::NET, "getblocks %d to %s limit %d from peer=%d\n",
                  (pindex ? pindex->nHeight : -1),
                  hashStop.IsNull() ? "end" : hashStop.ToString(), nLimit,
                  pfrom->id);
         for (; pindex; pindex = chainActive.Next(pindex)) {
             if (pindex->GetBlockHash() == hashStop) {
                 LogPrint(BCLog::NET, "  getblocks stopping at %d %s\n",
                          pindex->nHeight, pindex->GetBlockHash().ToString());
                 break;
             }
             // If pruning, don't inv blocks unless we have on disk and are
             // likely to still have for some reasonable time window (1 hour)
             // that block relay might require.
             const int nPrunedBlocksLikelyToHave =
                 MIN_BLOCKS_TO_KEEP -
                 3600 / chainparams.GetConsensus().nPowTargetSpacing;
             if (fPruneMode &&
                 (!(pindex->nStatus & BLOCK_HAVE_DATA) ||
                  pindex->nHeight <=
                      chainActive.Tip()->nHeight - nPrunedBlocksLikelyToHave)) {
                 LogPrint(
                     BCLog::NET,
                     " getblocks stopping, pruned or too old block at %d %s\n",
                     pindex->nHeight, pindex->GetBlockHash().ToString());
                 break;
             }
             pfrom->PushInventory(CInv(MSG_BLOCK, pindex->GetBlockHash()));
             if (--nLimit <= 0) {
                 // When this block is requested, we'll send an inv that'll
                 // trigger the peer to getblocks the next batch of inventory.
                 LogPrint(BCLog::NET, "  getblocks stopping at limit %d %s\n",
                          pindex->nHeight, pindex->GetBlockHash().ToString());
                 pfrom->hashContinue = pindex->GetBlockHash();
                 break;
             }
         }
     }
 
     else if (strCommand == NetMsgType::GETBLOCKTXN) {
         BlockTransactionsRequest req;
         vRecv >> req;
 
         std::shared_ptr<const CBlock> recent_block;
         {
             LOCK(cs_most_recent_block);
             if (most_recent_block_hash == req.blockhash) {
                 recent_block = most_recent_block;
             }
             // Unlock cs_most_recent_block to avoid cs_main lock inversion
         }
         if (recent_block) {
             SendBlockTransactions(*recent_block, req, pfrom, connman);
             return true;
         }
 
         LOCK(cs_main);
 
         BlockMap::iterator it = mapBlockIndex.find(req.blockhash);
         if (it == mapBlockIndex.end() ||
             !(it->second->nStatus & BLOCK_HAVE_DATA)) {
             LogPrintf("Peer %d sent us a getblocktxn for a block we don't have",
                       pfrom->id);
             return true;
         }
 
         if (it->second->nHeight < chainActive.Height() - MAX_BLOCKTXN_DEPTH) {
             // If an older block is requested (should never happen in practice,
             // but can happen in tests) send a block response instead of a
             // blocktxn response. Sending a full block response instead of a
             // small blocktxn response is preferable in the case where a peer
             // might maliciously send lots of getblocktxn requests to trigger
             // expensive disk reads, because it will require the peer to
             // actually receive all the data read from disk over the network.
             LogPrint(BCLog::NET,
                      "Peer %d sent us a getblocktxn for a block > %i deep",
                      pfrom->id, MAX_BLOCKTXN_DEPTH);
             CInv inv;
             inv.type = MSG_BLOCK;
             inv.hash = req.blockhash;
             pfrom->vRecvGetData.push_back(inv);
             ProcessGetData(config, pfrom, chainparams.GetConsensus(), connman,
                            interruptMsgProc);
             return true;
         }
 
         CBlock block;
         bool ret = ReadBlockFromDisk(block, it->second, config);
         assert(ret);
 
         SendBlockTransactions(block, req, pfrom, connman);
     }
 
     else if (strCommand == NetMsgType::GETHEADERS) {
         CBlockLocator locator;
         uint256 hashStop;
         vRecv >> locator >> hashStop;
 
         LOCK(cs_main);
         if (IsInitialBlockDownload() && !pfrom->fWhitelisted) {
             LogPrint(BCLog::NET, "Ignoring getheaders from peer=%d because "
                                  "node is in initial block download\n",
                      pfrom->id);
             return true;
         }
 
         CNodeState *nodestate = State(pfrom->GetId());
         const CBlockIndex *pindex = nullptr;
         if (locator.IsNull()) {
             // If locator is null, return the hashStop block
             BlockMap::iterator mi = mapBlockIndex.find(hashStop);
             if (mi == mapBlockIndex.end()) {
                 return true;
             }
             pindex = (*mi).second;
         } else {
             // Find the last block the caller has in the main chain
             pindex = FindForkInGlobalIndex(chainActive, locator);
             if (pindex) {
                 pindex = chainActive.Next(pindex);
             }
         }
 
         // we must use CBlocks, as CBlockHeaders won't include the 0x00 nTx
         // count at the end
         std::vector<CBlock> vHeaders;
         int nLimit = MAX_HEADERS_RESULTS;
         LogPrint(BCLog::NET, "getheaders %d to %s from peer=%d\n",
                  (pindex ? pindex->nHeight : -1),
                  hashStop.IsNull() ? "end" : hashStop.ToString(), pfrom->id);
         for (; pindex; pindex = chainActive.Next(pindex)) {
             vHeaders.push_back(pindex->GetBlockHeader());
             if (--nLimit <= 0 || pindex->GetBlockHash() == hashStop) {
                 break;
             }
         }
         // pindex can be nullptr either if we sent chainActive.Tip() OR
         // if our peer has chainActive.Tip() (and thus we are sending an empty
         // headers message). In both cases it's safe to update
         // pindexBestHeaderSent to be our tip.
         //
         // It is important that we simply reset the BestHeaderSent value here,
         // and not max(BestHeaderSent, newHeaderSent). We might have announced
         // the currently-being-connected tip using a compact block, which
         // resulted in the peer sending a headers request, which we respond to
         // without the new block. By resetting the BestHeaderSent, we ensure we
         // will re-announce the new block via headers (or compact blocks again)
         // in the SendMessages logic.
         nodestate->pindexBestHeaderSent = pindex ? pindex : chainActive.Tip();
         connman.PushMessage(pfrom,
                             msgMaker.Make(NetMsgType::HEADERS, vHeaders));
     }
 
     else if (strCommand == NetMsgType::TX) {
         // Stop processing the transaction early if
         // We are in blocks only mode and peer is either not whitelisted or
         // whitelistrelay is off
         if (!fRelayTxes &&
             (!pfrom->fWhitelisted ||
              !gArgs.GetBoolArg("-whitelistrelay", DEFAULT_WHITELISTRELAY))) {
             LogPrint(BCLog::NET,
                      "transaction sent in violation of protocol peer=%d\n",
                      pfrom->id);
             return true;
         }
 
         std::deque<COutPoint> vWorkQueue;
         std::vector<uint256> vEraseQueue;
         CTransactionRef ptx;
         vRecv >> ptx;
         const CTransaction &tx = *ptx;
 
         CInv inv(MSG_TX, tx.GetId());
         pfrom->AddInventoryKnown(inv);
 
         LOCK(cs_main);
 
         bool fMissingInputs = false;
         CValidationState state;
 
         pfrom->setAskFor.erase(inv.hash);
         mapAlreadyAskedFor.erase(inv.hash);
 
         std::list<CTransactionRef> lRemovedTxn;
 
         if (!AlreadyHave(inv) &&
             AcceptToMemoryPool(config, mempool, state, ptx, true,
                                &fMissingInputs, &lRemovedTxn)) {
             mempool.check(pcoinsTip);
             RelayTransaction(tx, connman);
             for (size_t i = 0; i < tx.vout.size(); i++) {
                 vWorkQueue.emplace_back(inv.hash, i);
             }
 
             pfrom->nLastTXTime = GetTime();
 
             LogPrint(BCLog::MEMPOOL, "AcceptToMemoryPool: peer=%d: accepted %s "
                                      "(poolsz %u txn, %u kB)\n",
                      pfrom->id, tx.GetId().ToString(), mempool.size(),
                      mempool.DynamicMemoryUsage() / 1000);
 
             // Recursively process any orphan transactions that depended on this
             // one
             std::set<NodeId> setMisbehaving;
             while (!vWorkQueue.empty()) {
                 auto itByPrev =
                     mapOrphanTransactionsByPrev.find(vWorkQueue.front());
                 vWorkQueue.pop_front();
                 if (itByPrev == mapOrphanTransactionsByPrev.end()) {
                     continue;
                 }
                 for (auto mi = itByPrev->second.begin();
                      mi != itByPrev->second.end(); ++mi) {
                     const CTransactionRef &porphanTx = (*mi)->second.tx;
                     const CTransaction &orphanTx = *porphanTx;
                     const uint256 &orphanId = orphanTx.GetId();
                     NodeId fromPeer = (*mi)->second.fromPeer;
                     bool fMissingInputs2 = false;
                     // Use a dummy CValidationState so someone can't setup nodes
                     // to counter-DoS based on orphan resolution (that is,
                     // feeding people an invalid transaction based on LegitTxX
                     // in order to get anyone relaying LegitTxX banned)
                     CValidationState stateDummy;
 
                     if (setMisbehaving.count(fromPeer)) {
                         continue;
                     }
                     if (AcceptToMemoryPool(config, mempool, stateDummy,
                                            porphanTx, true, &fMissingInputs2,
                                            &lRemovedTxn)) {
                         LogPrint(BCLog::MEMPOOL, "   accepted orphan tx %s\n",
                                  orphanId.ToString());
                         RelayTransaction(orphanTx, connman);
                         for (size_t i = 0; i < orphanTx.vout.size(); i++) {
                             vWorkQueue.emplace_back(orphanId, i);
                         }
                         vEraseQueue.push_back(orphanId);
                     } else if (!fMissingInputs2) {
                         int nDos = 0;
                         if (stateDummy.IsInvalid(nDos) && nDos > 0) {
                             // Punish peer that gave us an invalid orphan tx
                             Misbehaving(fromPeer, nDos, "invalid-orphan-tx");
                             setMisbehaving.insert(fromPeer);
                             LogPrint(BCLog::MEMPOOL,
                                      "   invalid orphan tx %s\n",
                                      orphanId.ToString());
                         }
                         // Has inputs but not accepted to mempool
                         // Probably non-standard or insufficient fee/priority
                         LogPrint(BCLog::MEMPOOL, "   removed orphan tx %s\n",
                                  orphanId.ToString());
                         vEraseQueue.push_back(orphanId);
                         if (!stateDummy.CorruptionPossible()) {
                             // Do not use rejection cache for witness
                             // transactions or witness-stripped transactions, as
                             // they can have been malleated. See
                             // https://github.com/bitcoin/bitcoin/issues/8279
                             // for details.
                             assert(recentRejects);
                             recentRejects->insert(orphanId);
                         }
                     }
                     mempool.check(pcoinsTip);
                 }
             }
 
             for (uint256 hash : vEraseQueue) {
                 EraseOrphanTx(hash);
             }
         } else if (fMissingInputs) {
             // It may be the case that the orphans parents have all been
             // rejected.
             bool fRejectedParents = false;
             for (const CTxIn &txin : tx.vin) {
                 if (recentRejects->contains(txin.prevout.hash)) {
                     fRejectedParents = true;
                     break;
                 }
             }
             if (!fRejectedParents) {
                 uint32_t nFetchFlags = GetFetchFlags(
                     pfrom, chainActive.Tip(), chainparams.GetConsensus());
                 for (const CTxIn &txin : tx.vin) {
                     CInv _inv(MSG_TX | nFetchFlags, txin.prevout.hash);
                     pfrom->AddInventoryKnown(_inv);
                     if (!AlreadyHave(_inv)) {
                         pfrom->AskFor(_inv);
                     }
                 }
                 AddOrphanTx(ptx, pfrom->GetId());
 
                 // DoS prevention: do not allow mapOrphanTransactions to grow
                 // unbounded
                 unsigned int nMaxOrphanTx = (unsigned int)std::max(
                     int64_t(0),
                     gArgs.GetArg("-maxorphantx",
                                  DEFAULT_MAX_ORPHAN_TRANSACTIONS));
                 unsigned int nEvicted = LimitOrphanTxSize(nMaxOrphanTx);
                 if (nEvicted > 0) {
                     LogPrint(BCLog::MEMPOOL,
                              "mapOrphan overflow, removed %u tx\n", nEvicted);
                 }
             } else {
                 LogPrint(BCLog::MEMPOOL,
                          "not keeping orphan with rejected parents %s\n",
                          tx.GetId().ToString());
                 // We will continue to reject this tx since it has rejected
                 // parents so avoid re-requesting it from other peers.
                 recentRejects->insert(tx.GetId());
             }
         } else {
             if (!state.CorruptionPossible()) {
                 // Do not use rejection cache for witness transactions or
                 // witness-stripped transactions, as they can have been
                 // malleated. See https://github.com/bitcoin/bitcoin/issues/8279
                 // for details.
                 assert(recentRejects);
                 recentRejects->insert(tx.GetId());
                 if (RecursiveDynamicUsage(*ptx) < 100000) {
                     AddToCompactExtraTransactions(ptx);
                 }
             }
 
             if (pfrom->fWhitelisted &&
                 gArgs.GetBoolArg("-whitelistforcerelay",
                                  DEFAULT_WHITELISTFORCERELAY)) {
                 // Always relay transactions received from whitelisted peers,
                 // even if they were already in the mempool or rejected from it
                 // due to policy, allowing the node to function as a gateway for
                 // nodes hidden behind it.
                 //
                 // Never relay transactions that we would assign a non-zero DoS
                 // score for, as we expect peers to do the same with us in that
                 // case.
                 int nDoS = 0;
                 if (!state.IsInvalid(nDoS) || nDoS == 0) {
                     LogPrintf("Force relaying tx %s from whitelisted peer=%d\n",
                               tx.GetId().ToString(), pfrom->id);
                     RelayTransaction(tx, connman);
                 } else {
                     LogPrintf("Not relaying invalid transaction %s from "
                               "whitelisted peer=%d (%s)\n",
                               tx.GetId().ToString(), pfrom->id,
                               FormatStateMessage(state));
                 }
             }
         }
 
         for (const CTransactionRef &removedTx : lRemovedTxn) {
             AddToCompactExtraTransactions(removedTx);
         }
 
         int nDoS = 0;
         if (state.IsInvalid(nDoS)) {
             LogPrint(
                 BCLog::MEMPOOLREJ, "%s from peer=%d was not accepted: %s\n",
                 tx.GetHash().ToString(), pfrom->id, FormatStateMessage(state));
             // Never send AcceptToMemoryPool's internal codes over P2P.
             if (state.GetRejectCode() > 0 &&
                 state.GetRejectCode() < REJECT_INTERNAL) {
                 connman.PushMessage(
                     pfrom,
                     msgMaker.Make(NetMsgType::REJECT, strCommand,
                                   uint8_t(state.GetRejectCode()),
                                   state.GetRejectReason().substr(
                                       0, MAX_REJECT_MESSAGE_LENGTH),
                                   inv.hash));
             }
             if (nDoS > 0) {
                 Misbehaving(pfrom, nDoS, state.GetRejectReason());
             }
         }
     }
 
     // Ignore blocks received while importing
     else if (strCommand == NetMsgType::CMPCTBLOCK && !fImporting && !fReindex) {
         CBlockHeaderAndShortTxIDs cmpctblock;
         vRecv >> cmpctblock;
 
         {
             LOCK(cs_main);
 
             if (mapBlockIndex.find(cmpctblock.header.hashPrevBlock) ==
                 mapBlockIndex.end()) {
                 // Doesn't connect (or is genesis), instead of DoSing in
                 // AcceptBlockHeader, request deeper headers
                 if (!IsInitialBlockDownload()) {
                     connman.PushMessage(
                         pfrom,
                         msgMaker.Make(NetMsgType::GETHEADERS,
                                       chainActive.GetLocator(pindexBestHeader),
                                       uint256()));
                 }
                 return true;
             }
         }
 
         const CBlockIndex *pindex = nullptr;
         CValidationState state;
         if (!ProcessNewBlockHeaders(config, {cmpctblock.header}, state,
                                     &pindex)) {
             int nDoS;
             if (state.IsInvalid(nDoS)) {
                 if (nDoS > 0) {
                     LOCK(cs_main);
                     Misbehaving(pfrom, nDoS, state.GetRejectReason());
                 }
                 LogPrintf("Peer %d sent us invalid header via cmpctblock\n",
                           pfrom->id);
                 return true;
             }
         }
 
         // When we succeed in decoding a block's txids from a cmpctblock
         // message we typically jump to the BLOCKTXN handling code, with a
         // dummy (empty) BLOCKTXN message, to re-use the logic there in
         // completing processing of the putative block (without cs_main).
         bool fProcessBLOCKTXN = false;
         CDataStream blockTxnMsg(SER_NETWORK, PROTOCOL_VERSION);
 
         // If we end up treating this as a plain headers message, call that as
         // well
         // without cs_main.
         bool fRevertToHeaderProcessing = false;
         CDataStream vHeadersMsg(SER_NETWORK, PROTOCOL_VERSION);
 
         // Keep a CBlock for "optimistic" compactblock reconstructions (see
         // below)
         std::shared_ptr<CBlock> pblock = std::make_shared<CBlock>();
         bool fBlockReconstructed = false;
 
         {
             LOCK(cs_main);
             // If AcceptBlockHeader returned true, it set pindex
             assert(pindex);
             UpdateBlockAvailability(pfrom->GetId(), pindex->GetBlockHash());
 
             std::map<uint256,
                      std::pair<NodeId, std::list<QueuedBlock>::iterator>>::
                 iterator blockInFlightIt =
                     mapBlocksInFlight.find(pindex->GetBlockHash());
             bool fAlreadyInFlight = blockInFlightIt != mapBlocksInFlight.end();
 
             if (pindex->nStatus & BLOCK_HAVE_DATA) {
                 // Nothing to do here
                 return true;
             }
 
             if (pindex->nChainWork <=
                     chainActive.Tip()->nChainWork || // We know something better
                 pindex->nTx != 0) {
                 // We had this block at some point, but pruned it
                 if (fAlreadyInFlight) {
                     // We requested this block for some reason, but our mempool
                     // will probably be useless so we just grab the block via
                     // normal getdata.
                     std::vector<CInv> vInv(1);
                     vInv[0] = CInv(
                         MSG_BLOCK | GetFetchFlags(pfrom, pindex->pprev,
                                                   chainparams.GetConsensus()),
                         cmpctblock.header.GetHash());
                     connman.PushMessage(
                         pfrom, msgMaker.Make(NetMsgType::GETDATA, vInv));
                 }
                 return true;
             }
 
             // If we're not close to tip yet, give up and let parallel block
             // fetch work its magic.
             if (!fAlreadyInFlight &&
                 !CanDirectFetch(chainparams.GetConsensus())) {
                 return true;
             }
 
             CNodeState *nodestate = State(pfrom->GetId());
 
             // We want to be a bit conservative just to be extra careful about
             // DoS possibilities in compact block processing...
             if (pindex->nHeight <= chainActive.Height() + 2) {
                 if ((!fAlreadyInFlight &&
                      nodestate->nBlocksInFlight <
                          MAX_BLOCKS_IN_TRANSIT_PER_PEER) ||
                     (fAlreadyInFlight &&
                      blockInFlightIt->second.first == pfrom->GetId())) {
                     std::list<QueuedBlock>::iterator *queuedBlockIt = nullptr;
                     if (!MarkBlockAsInFlight(config, pfrom->GetId(),
                                              pindex->GetBlockHash(),
                                              chainparams.GetConsensus(), pindex,
                                              &queuedBlockIt)) {
                         if (!(*queuedBlockIt)->partialBlock) {
                             (*queuedBlockIt)
                                 ->partialBlock.reset(
                                     new PartiallyDownloadedBlock(config,
                                                                  &mempool));
                         } else {
                             // The block was already in flight using compact
                             // blocks from the same peer.
                             LogPrint(BCLog::NET, "Peer sent us compact block "
                                                  "we were already syncing!\n");
                             return true;
                         }
                     }
 
                     PartiallyDownloadedBlock &partialBlock =
                         *(*queuedBlockIt)->partialBlock;
                     ReadStatus status =
                         partialBlock.InitData(cmpctblock, vExtraTxnForCompact);
                     if (status == READ_STATUS_INVALID) {
                         // Reset in-flight state in case of whitelist
                         MarkBlockAsReceived(pindex->GetBlockHash());
                         Misbehaving(pfrom, 100, "invalid-cmpctblk");
                         LogPrintf("Peer %d sent us invalid compact block\n",
                                   pfrom->id);
                         return true;
                     } else if (status == READ_STATUS_FAILED) {
                         // Duplicate txindices, the block is now in-flight, so
                         // just request it.
                         std::vector<CInv> vInv(1);
                         vInv[0] =
                             CInv(MSG_BLOCK |
                                      GetFetchFlags(pfrom, pindex->pprev,
                                                    chainparams.GetConsensus()),
                                  cmpctblock.header.GetHash());
                         connman.PushMessage(
                             pfrom, msgMaker.Make(NetMsgType::GETDATA, vInv));
                         return true;
                     }
 
                     BlockTransactionsRequest req;
                     for (size_t i = 0; i < cmpctblock.BlockTxCount(); i++) {
                         if (!partialBlock.IsTxAvailable(i)) {
                             req.indices.push_back(i);
                         }
                     }
                     if (req.indices.empty()) {
                         // Dirty hack to jump to BLOCKTXN code (TODO: move
                         // message handling into their own functions)
                         BlockTransactions txn;
                         txn.blockhash = cmpctblock.header.GetHash();
                         blockTxnMsg << txn;
                         fProcessBLOCKTXN = true;
                     } else {
                         req.blockhash = pindex->GetBlockHash();
                         connman.PushMessage(
                             pfrom, msgMaker.Make(NetMsgType::GETBLOCKTXN, req));
                     }
                 } else {
                     // This block is either already in flight from a different
                     // peer, or this peer has too many blocks outstanding to
                     // download from. Optimistically try to reconstruct anyway
                     // since we might be able to without any round trips.
                     PartiallyDownloadedBlock tempBlock(config, &mempool);
                     ReadStatus status =
                         tempBlock.InitData(cmpctblock, vExtraTxnForCompact);
                     if (status != READ_STATUS_OK) {
                         // TODO: don't ignore failures
                         return true;
                     }
                     std::vector<CTransactionRef> dummy;
                     status = tempBlock.FillBlock(*pblock, dummy);
                     if (status == READ_STATUS_OK) {
                         fBlockReconstructed = true;
                     }
                 }
             } else {
                 if (fAlreadyInFlight) {
                     // We requested this block, but its far into the future, so
                     // our mempool will probably be useless - request the block
                     // normally.
                     std::vector<CInv> vInv(1);
                     vInv[0] = CInv(
                         MSG_BLOCK | GetFetchFlags(pfrom, pindex->pprev,
                                                   chainparams.GetConsensus()),
                         cmpctblock.header.GetHash());
                     connman.PushMessage(
                         pfrom, msgMaker.Make(NetMsgType::GETDATA, vInv));
                     return true;
                 } else {
                     // If this was an announce-cmpctblock, we want the same
                     // treatment as a header message. Dirty hack to process as
                     // if it were just a headers message (TODO: move message
                     // handling into their own functions)
                     std::vector<CBlock> headers;
                     headers.push_back(cmpctblock.header);
                     vHeadersMsg << headers;
                     fRevertToHeaderProcessing = true;
                 }
             }
         } // cs_main
 
         if (fProcessBLOCKTXN) {
             return ProcessMessage(config, pfrom, NetMsgType::BLOCKTXN,
                                   blockTxnMsg, nTimeReceived, chainparams,
                                   connman, interruptMsgProc);
         }
 
         if (fRevertToHeaderProcessing) {
             return ProcessMessage(config, pfrom, NetMsgType::HEADERS,
                                   vHeadersMsg, nTimeReceived, chainparams,
                                   connman, interruptMsgProc);
         }
 
         if (fBlockReconstructed) {
             // If we got here, we were able to optimistically reconstruct a
             // block that is in flight from some other peer.
             {
                 LOCK(cs_main);
                 mapBlockSource.emplace(pblock->GetHash(),
                                        std::make_pair(pfrom->GetId(), false));
             }
             bool fNewBlock = false;
             ProcessNewBlock(config, pblock, true, &fNewBlock);
             if (fNewBlock) {
                 pfrom->nLastBlockTime = GetTime();
             }
 
             // hold cs_main for CBlockIndex::IsValid()
             LOCK(cs_main);
             if (pindex->IsValid(BLOCK_VALID_TRANSACTIONS)) {
                 // Clear download state for this block, which is in process from
                 // some other peer. We do this after calling. ProcessNewBlock so
                 // that a malleated cmpctblock announcement can't be used to
                 // interfere with block relay.
                 MarkBlockAsReceived(pblock->GetHash());
             }
         }
 
     }
 
     else if (strCommand == NetMsgType::BLOCKTXN && !fImporting &&
              !fReindex) // Ignore blocks received while importing
     {
         BlockTransactions resp;
         vRecv >> resp;
 
         std::shared_ptr<CBlock> pblock = std::make_shared<CBlock>();
         bool fBlockRead = false;
         {
             LOCK(cs_main);
 
             std::map<uint256,
                      std::pair<NodeId, std::list<QueuedBlock>::iterator>>::
                 iterator it = mapBlocksInFlight.find(resp.blockhash);
             if (it == mapBlocksInFlight.end() ||
                 !it->second.second->partialBlock ||
                 it->second.first != pfrom->GetId()) {
                 LogPrint(BCLog::NET,
                          "Peer %d sent us block transactions for block "
                          "we weren't expecting\n",
                          pfrom->id);
                 return true;
             }
 
             PartiallyDownloadedBlock &partialBlock =
                 *it->second.second->partialBlock;
             ReadStatus status = partialBlock.FillBlock(*pblock, resp.txn);
             if (status == READ_STATUS_INVALID) {
                 // Reset in-flight state in case of whitelist.
                 MarkBlockAsReceived(resp.blockhash);
                 Misbehaving(pfrom, 100, "invalid-cmpctblk-txns");
                 LogPrintf("Peer %d sent us invalid compact block/non-matching "
                           "block transactions\n",
                           pfrom->id);
                 return true;
             } else if (status == READ_STATUS_FAILED) {
                 // Might have collided, fall back to getdata now :(
                 std::vector<CInv> invs;
                 invs.push_back(
                     CInv(MSG_BLOCK | GetFetchFlags(pfrom, chainActive.Tip(),
                                                    chainparams.GetConsensus()),
                          resp.blockhash));
                 connman.PushMessage(pfrom,
                                     msgMaker.Make(NetMsgType::GETDATA, invs));
             } else {
                 // Block is either okay, or possibly we received
                 // READ_STATUS_CHECKBLOCK_FAILED.
                 // Note that CheckBlock can only fail for one of a few reasons:
                 // 1. bad-proof-of-work (impossible here, because we've already
                 //    accepted the header)
                 // 2. merkleroot doesn't match the transactions given (already
                 //    caught in FillBlock with READ_STATUS_FAILED, so
                 //    impossible here)
                 // 3. the block is otherwise invalid (eg invalid coinbase,
                 //    block is too big, too many legacy sigops, etc).
                 // So if CheckBlock failed, #3 is the only possibility.
                 // Under BIP 152, we don't DoS-ban unless proof of work is
                 // invalid (we don't require all the stateless checks to have
                 // been run). This is handled below, so just treat this as
                 // though the block was successfully read, and rely on the
                 // handling in ProcessNewBlock to ensure the block index is
                 // updated, reject messages go out, etc.
 
                 // it is now an empty pointer
                 MarkBlockAsReceived(resp.blockhash);
                 fBlockRead = true;
                 // mapBlockSource is only used for sending reject messages and
                 // DoS scores, so the race between here and cs_main in
                 // ProcessNewBlock is fine. BIP 152 permits peers to relay
                 // compact blocks after validating the header only; we should
                 // not punish peers if the block turns out to be invalid.
                 mapBlockSource.emplace(resp.blockhash,
                                        std::make_pair(pfrom->GetId(), false));
             }
         } // Don't hold cs_main when we call into ProcessNewBlock
         if (fBlockRead) {
             bool fNewBlock = false;
             // Since we requested this block (it was in mapBlocksInFlight),
             // force it to be processed, even if it would not be a candidate for
             // new tip (missing previous block, chain not long enough, etc)
             ProcessNewBlock(config, pblock, true, &fNewBlock);
             if (fNewBlock) {
                 pfrom->nLastBlockTime = GetTime();
             }
         }
     }
 
     // Ignore headers received while importing
     else if (strCommand == NetMsgType::HEADERS && !fImporting && !fReindex) {
         std::vector<CBlockHeader> headers;
 
         // Bypass the normal CBlock deserialization, as we don't want to risk
         // deserializing 2000 full blocks.
         unsigned int nCount = ReadCompactSize(vRecv);
         if (nCount > MAX_HEADERS_RESULTS) {
             LOCK(cs_main);
             Misbehaving(pfrom, 20, "too-many-headers");
             return error("headers message size = %u", nCount);
         }
         headers.resize(nCount);
         for (unsigned int n = 0; n < nCount; n++) {
             vRecv >> headers[n];
             // Ignore tx count; assume it is 0.
             ReadCompactSize(vRecv);
         }
 
         if (nCount == 0) {
             // Nothing interesting. Stop asking this peers for more headers.
             return true;
         }
 
         const CBlockIndex *pindexLast = nullptr;
         {
             LOCK(cs_main);
             CNodeState *nodestate = State(pfrom->GetId());
 
             // If this looks like it could be a block announcement (nCount <
             // MAX_BLOCKS_TO_ANNOUNCE), use special logic for handling headers
             // that
             // don't connect:
             // - Send a getheaders message in response to try to connect the
             // chain.
             // - The peer can send up to MAX_UNCONNECTING_HEADERS in a row that
             //   don't connect before giving DoS points
             // - Once a headers message is received that is valid and does
             // connect,
             //   nUnconnectingHeaders gets reset back to 0.
             if (mapBlockIndex.find(headers[0].hashPrevBlock) ==
                     mapBlockIndex.end() &&
                 nCount < MAX_BLOCKS_TO_ANNOUNCE) {
                 nodestate->nUnconnectingHeaders++;
                 connman.PushMessage(
                     pfrom,
                     msgMaker.Make(NetMsgType::GETHEADERS,
                                   chainActive.GetLocator(pindexBestHeader),
                                   uint256()));
                 LogPrint(BCLog::NET, "received header %s: missing prev block "
                                      "%s, sending getheaders (%d) to end "
                                      "(peer=%d, nUnconnectingHeaders=%d)\n",
                          headers[0].GetHash().ToString(),
                          headers[0].hashPrevBlock.ToString(),
                          pindexBestHeader->nHeight, pfrom->id,
                          nodestate->nUnconnectingHeaders);
                 // Set hashLastUnknownBlock for this peer, so that if we
                 // eventually get the headers - even from a different peer -
                 // we can use this peer to download.
                 UpdateBlockAvailability(pfrom->GetId(),
                                         headers.back().GetHash());
 
                 if (nodestate->nUnconnectingHeaders %
                         MAX_UNCONNECTING_HEADERS ==
                     0) {
                     // The peer is sending us many headers we can't connect.
                     Misbehaving(pfrom, 20, "too-many-unconnected-headers");
                 }
                 return true;
             }
 
             uint256 hashLastBlock;
             for (const CBlockHeader &header : headers) {
                 if (!hashLastBlock.IsNull() &&
                     header.hashPrevBlock != hashLastBlock) {
                     Misbehaving(pfrom, 20, "disconnected-header");
                     return error("non-continuous headers sequence");
                 }
                 hashLastBlock = header.GetHash();
             }
         }
 
         CValidationState state;
         if (!ProcessNewBlockHeaders(config, headers, state, &pindexLast)) {
             int nDoS;
             if (state.IsInvalid(nDoS)) {
                 if (nDoS > 0) {
                     LOCK(cs_main);
                     Misbehaving(pfrom, nDoS, state.GetRejectReason());
                 }
                 return error("invalid header received");
             }
         }
 
         {
             LOCK(cs_main);
             CNodeState *nodestate = State(pfrom->GetId());
             if (nodestate->nUnconnectingHeaders > 0) {
                 LogPrint(BCLog::NET,
                          "peer=%d: resetting nUnconnectingHeaders (%d -> 0)\n",
                          pfrom->id, nodestate->nUnconnectingHeaders);
             }
             nodestate->nUnconnectingHeaders = 0;
 
             assert(pindexLast);
             UpdateBlockAvailability(pfrom->GetId(), pindexLast->GetBlockHash());
 
             if (nCount == MAX_HEADERS_RESULTS) {
                 // Headers message had its maximum size; the peer may have more
                 // headers.
                 // TODO: optimize: if pindexLast is an ancestor of
                 // chainActive.Tip or pindexBestHeader, continue from there
                 // instead.
                 LogPrint(
                     BCLog::NET,
                     "more getheaders (%d) to end to peer=%d (startheight:%d)\n",
                     pindexLast->nHeight, pfrom->id, pfrom->nStartingHeight);
                 connman.PushMessage(
                     pfrom,
                     msgMaker.Make(NetMsgType::GETHEADERS,
                                   chainActive.GetLocator(pindexLast),
                                   uint256()));
             }
 
             bool fCanDirectFetch = CanDirectFetch(chainparams.GetConsensus());
             // If this set of headers is valid and ends in a block with at least
             // as much work as our tip, download as much as possible.
             if (fCanDirectFetch && pindexLast->IsValid(BLOCK_VALID_TREE) &&
                 chainActive.Tip()->nChainWork <= pindexLast->nChainWork) {
                 std::vector<const CBlockIndex *> vToFetch;
                 const CBlockIndex *pindexWalk = pindexLast;
                 // Calculate all the blocks we'd need to switch to pindexLast,
                 // up to a limit.
                 while (pindexWalk && !chainActive.Contains(pindexWalk) &&
                        vToFetch.size() <= MAX_BLOCKS_IN_TRANSIT_PER_PEER) {
                     if (!(pindexWalk->nStatus & BLOCK_HAVE_DATA) &&
                         !mapBlocksInFlight.count(pindexWalk->GetBlockHash())) {
                         // We don't have this block, and it's not yet in flight.
                         vToFetch.push_back(pindexWalk);
                     }
                     pindexWalk = pindexWalk->pprev;
                 }
                 // If pindexWalk still isn't on our main chain, we're looking at
                 // a very large reorg at a time we think we're close to caught
                 // up to the main chain -- this shouldn't really happen. Bail
                 // out on the direct fetch and rely on parallel download
                 // instead.
                 if (!chainActive.Contains(pindexWalk)) {
                     LogPrint(BCLog::NET,
                              "Large reorg, won't direct fetch to %s (%d)\n",
                              pindexLast->GetBlockHash().ToString(),
                              pindexLast->nHeight);
                 } else {
                     std::vector<CInv> vGetData;
                     // Download as much as possible, from earliest to latest.
                     for (const CBlockIndex *pindex :
                          boost::adaptors::reverse(vToFetch)) {
                         if (nodestate->nBlocksInFlight >=
                             MAX_BLOCKS_IN_TRANSIT_PER_PEER) {
                             // Can't download any more from this peer
                             break;
                         }
                         uint32_t nFetchFlags = GetFetchFlags(
                             pfrom, pindex->pprev, chainparams.GetConsensus());
                         vGetData.push_back(CInv(MSG_BLOCK | nFetchFlags,
                                                 pindex->GetBlockHash()));
                         MarkBlockAsInFlight(config, pfrom->GetId(),
                                             pindex->GetBlockHash(),
                                             chainparams.GetConsensus(), pindex);
                         LogPrint(BCLog::NET,
                                  "Requesting block %s from  peer=%d\n",
                                  pindex->GetBlockHash().ToString(), pfrom->id);
                     }
                     if (vGetData.size() > 1) {
                         LogPrint(BCLog::NET, "Downloading blocks toward %s "
                                              "(%d) via headers direct fetch\n",
                                  pindexLast->GetBlockHash().ToString(),
                                  pindexLast->nHeight);
                     }
                     if (vGetData.size() > 0) {
                         if (nodestate->fSupportsDesiredCmpctVersion &&
                             vGetData.size() == 1 &&
                             mapBlocksInFlight.size() == 1 &&
                             pindexLast->pprev->IsValid(BLOCK_VALID_CHAIN)) {
                             // In any case, we want to download using a compact
                             // block, not a regular one.
                             vGetData[0] =
                                 CInv(MSG_CMPCT_BLOCK, vGetData[0].hash);
                         }
                         connman.PushMessage(
                             pfrom,
                             msgMaker.Make(NetMsgType::GETDATA, vGetData));
                     }
                 }
             }
         }
     }
 
     else if (strCommand == NetMsgType::BLOCK && !fImporting &&
              !fReindex) // Ignore blocks received while importing
     {
         std::shared_ptr<CBlock> pblock = std::make_shared<CBlock>();
         vRecv >> *pblock;
 
         LogPrint(BCLog::NET, "received block %s peer=%d\n",
                  pblock->GetHash().ToString(), pfrom->id);
 
         // Process all blocks from whitelisted peers, even if not requested,
         // unless we're still syncing with the network. Such an unrequested
         // block may still be processed, subject to the conditions in
         // AcceptBlock().
         bool forceProcessing = pfrom->fWhitelisted && !IsInitialBlockDownload();
         const uint256 hash(pblock->GetHash());
         {
             LOCK(cs_main);
             // Also always process if we requested the block explicitly, as we
             // may need it even though it is not a candidate for a new best tip.
             forceProcessing |= MarkBlockAsReceived(hash);
             // mapBlockSource is only used for sending reject messages and DoS
             // scores, so the race between here and cs_main in ProcessNewBlock
             // is fine.
             mapBlockSource.emplace(hash, std::make_pair(pfrom->GetId(), true));
         }
         bool fNewBlock = false;
         ProcessNewBlock(config, pblock, forceProcessing, &fNewBlock);
         if (fNewBlock) {
             pfrom->nLastBlockTime = GetTime();
         }
     }
 
     else if (strCommand == NetMsgType::GETADDR) {
         // This asymmetric behavior for inbound and outbound connections was
         // introduced to prevent a fingerprinting attack: an attacker can send
         // specific fake addresses to users' AddrMan and later request them by
         // sending getaddr messages. Making nodes which are behind NAT and can
         // only make outgoing connections ignore the getaddr message mitigates
         // the attack.
         if (!pfrom->fInbound) {
             LogPrint(BCLog::NET,
                      "Ignoring \"getaddr\" from outbound connection. peer=%d\n",
                      pfrom->id);
             return true;
         }
 
         // Only send one GetAddr response per connection to reduce resource
         // waste and discourage addr stamping of INV announcements.
         if (pfrom->fSentAddr) {
             LogPrint(BCLog::NET, "Ignoring repeated \"getaddr\". peer=%d\n",
                      pfrom->id);
             return true;
         }
         pfrom->fSentAddr = true;
 
         pfrom->vAddrToSend.clear();
         std::vector<CAddress> vAddr = connman.GetAddresses();
         FastRandomContext insecure_rand;
         for (const CAddress &addr : vAddr) {
             pfrom->PushAddress(addr, insecure_rand);
         }
     }
 
     else if (strCommand == NetMsgType::MEMPOOL) {
         if (!(pfrom->GetLocalServices() & NODE_BLOOM) && !pfrom->fWhitelisted) {
             LogPrint(BCLog::NET, "mempool request with bloom filters disabled, "
                                  "disconnect peer=%d\n",
                      pfrom->GetId());
             pfrom->fDisconnect = true;
             return true;
         }
 
         if (connman.OutboundTargetReached(false) && !pfrom->fWhitelisted) {
             LogPrint(BCLog::NET, "mempool request with bandwidth limit "
                                  "reached, disconnect peer=%d\n",
                      pfrom->GetId());
             pfrom->fDisconnect = true;
             return true;
         }
 
         LOCK(pfrom->cs_inventory);
         pfrom->fSendMempool = true;
     }
 
     else if (strCommand == NetMsgType::PING) {
         if (pfrom->nVersion > BIP0031_VERSION) {
             uint64_t nonce = 0;
             vRecv >> nonce;
             // Echo the message back with the nonce. This allows for two useful
             // features:
             //
             // 1) A remote node can quickly check if the connection is
             // operational.
             // 2) Remote nodes can measure the latency of the network thread. If
             // this node is overloaded it won't respond to pings quickly and the
             // remote node can avoid sending us more work, like chain download
             // requests.
             //
             // The nonce stops the remote getting confused between different
             // pings: without it, if the remote node sends a ping once per
             // second and this node takes 5 seconds to respond to each, the 5th
             // ping the remote sends would appear to return very quickly.
             connman.PushMessage(pfrom, msgMaker.Make(NetMsgType::PONG, nonce));
         }
     }
 
     else if (strCommand == NetMsgType::PONG) {
         int64_t pingUsecEnd = nTimeReceived;
         uint64_t nonce = 0;
         size_t nAvail = vRecv.in_avail();
         bool bPingFinished = false;
         std::string sProblem;
 
         if (nAvail >= sizeof(nonce)) {
             vRecv >> nonce;
 
             // Only process pong message if there is an outstanding ping (old
             // ping without nonce should never pong)
             if (pfrom->nPingNonceSent != 0) {
                 if (nonce == pfrom->nPingNonceSent) {
                     // Matching pong received, this ping is no longer
                     // outstanding
                     bPingFinished = true;
                     int64_t pingUsecTime = pingUsecEnd - pfrom->nPingUsecStart;
                     if (pingUsecTime > 0) {
                         // Successful ping time measurement, replace previous
                         pfrom->nPingUsecTime = pingUsecTime;
                         pfrom->nMinPingUsecTime = std::min(
                             pfrom->nMinPingUsecTime.load(), pingUsecTime);
                     } else {
                         // This should never happen
                         sProblem = "Timing mishap";
                     }
                 } else {
                     // Nonce mismatches are normal when pings are overlapping
                     sProblem = "Nonce mismatch";
                     if (nonce == 0) {
                         // This is most likely a bug in another implementation
                         // somewhere; cancel this ping
                         bPingFinished = true;
                         sProblem = "Nonce zero";
                     }
                 }
             } else {
                 sProblem = "Unsolicited pong without ping";
             }
         } else {
             // This is most likely a bug in another implementation somewhere;
             // cancel this ping
             bPingFinished = true;
             sProblem = "Short payload";
         }
 
         if (!(sProblem.empty())) {
             LogPrint(BCLog::NET,
                      "pong peer=%d: %s, %x expected, %x received, %u bytes\n",
                      pfrom->id, sProblem, pfrom->nPingNonceSent, nonce, nAvail);
         }
         if (bPingFinished) {
             pfrom->nPingNonceSent = 0;
         }
     }
 
     else if (strCommand == NetMsgType::FILTERLOAD) {
         CBloomFilter filter;
         vRecv >> filter;
 
         if (!filter.IsWithinSizeConstraints()) {
             // There is no excuse for sending a too-large filter
             LOCK(cs_main);
             Misbehaving(pfrom, 100, "oversized-bloom-filter");
         } else {
             LOCK(pfrom->cs_filter);
             delete pfrom->pfilter;
             pfrom->pfilter = new CBloomFilter(filter);
             pfrom->pfilter->UpdateEmptyFull();
             pfrom->fRelayTxes = true;
         }
     }
 
     else if (strCommand == NetMsgType::FILTERADD) {
         std::vector<uint8_t> vData;
         vRecv >> vData;
 
         // Nodes must NEVER send a data item > 520 bytes (the max size for a
         // script data object, and thus, the maximum size any matched object can
         // have) in a filteradd message.
         bool bad = false;
         if (vData.size() > MAX_SCRIPT_ELEMENT_SIZE) {
             bad = true;
         } else {
             LOCK(pfrom->cs_filter);
             if (pfrom->pfilter) {
                 pfrom->pfilter->insert(vData);
             } else {
                 bad = true;
             }
         }
         if (bad) {
             LOCK(cs_main);
             // The structure of this code doesn't really allow for a good error
             // code. We'll go generic.
             Misbehaving(pfrom, 100, "invalid-filteradd");
         }
     }
 
     else if (strCommand == NetMsgType::FILTERCLEAR) {
         LOCK(pfrom->cs_filter);
         if (pfrom->GetLocalServices() & NODE_BLOOM) {
             delete pfrom->pfilter;
             pfrom->pfilter = new CBloomFilter();
         }
         pfrom->fRelayTxes = true;
     }
 
     else if (strCommand == NetMsgType::FEEFILTER) {
         Amount newFeeFilter(0);
         vRecv >> newFeeFilter;
         if (MoneyRange(newFeeFilter)) {
             {
                 LOCK(pfrom->cs_feeFilter);
                 pfrom->minFeeFilter = newFeeFilter;
             }
             LogPrint(BCLog::NET, "received: feefilter of %s from peer=%d\n",
                      CFeeRate(newFeeFilter).ToString(), pfrom->id);
         }
     }
 
     else if (strCommand == NetMsgType::NOTFOUND) {
         // We do not care about the NOTFOUND message, but logging an Unknown
         // Command message would be undesirable as we transmit it ourselves.
     }
 
     else {
         // Ignore unknown commands for extensibility
         LogPrint(BCLog::NET, "Unknown command \"%s\" from peer=%d\n",
                  SanitizeString(strCommand), pfrom->id);
     }
 
     return true;
 }
 
 static bool SendRejectsAndCheckIfBanned(CNode *pnode, CConnman &connman) {
     AssertLockHeld(cs_main);
     CNodeState &state = *State(pnode->GetId());
 
     for (const CBlockReject &reject : state.rejects) {
         connman.PushMessage(
             pnode,
             CNetMsgMaker(INIT_PROTO_VERSION)
                 .Make(NetMsgType::REJECT, std::string(NetMsgType::BLOCK),
                       reject.chRejectCode, reject.strRejectReason,
                       reject.hashBlock));
     }
     state.rejects.clear();
 
     if (state.fShouldBan) {
         state.fShouldBan = false;
         if (pnode->fWhitelisted) {
             LogPrintf("Warning: not punishing whitelisted peer %s!\n",
                       pnode->addr.ToString());
         } else if (pnode->fAddnode) {
             LogPrintf("Warning: not punishing addnoded peer %s!\n",
                       pnode->addr.ToString());
         } else {
             pnode->fDisconnect = true;
             if (pnode->addr.IsLocal()) {
                 LogPrintf("Warning: not banning local peer %s!\n",
                           pnode->addr.ToString());
             } else {
                 connman.Ban(pnode->addr, BanReasonNodeMisbehaving);
             }
         }
         return true;
     }
     return false;
 }
 
 bool ProcessMessages(const Config &config, CNode *pfrom, CConnman &connman,
                      const std::atomic<bool> &interruptMsgProc) {
     const CChainParams &chainparams = config.GetChainParams();
     //
     // Message format
     //  (4) message start
     //  (12) command
     //  (4) size
     //  (4) checksum
     //  (x) data
     //
     bool fMoreWork = false;
 
     if (!pfrom->vRecvGetData.empty()) {
         ProcessGetData(config, pfrom, chainparams.GetConsensus(), connman,
                        interruptMsgProc);
     }
 
     if (pfrom->fDisconnect) {
         return false;
     }
 
     // this maintains the order of responses
     if (!pfrom->vRecvGetData.empty()) {
         return true;
     }
 
     // Don't bother if send buffer is too full to respond anyway
     if (pfrom->fPauseSend) {
         return false;
     }
 
     std::list<CNetMessage> msgs;
     {
         LOCK(pfrom->cs_vProcessMsg);
         if (pfrom->vProcessMsg.empty()) {
             return false;
         }
         // Just take one message
         msgs.splice(msgs.begin(), pfrom->vProcessMsg,
                     pfrom->vProcessMsg.begin());
         pfrom->nProcessQueueSize -=
             msgs.front().vRecv.size() + CMessageHeader::HEADER_SIZE;
         pfrom->fPauseRecv =
             pfrom->nProcessQueueSize > connman.GetReceiveFloodSize();
         fMoreWork = !pfrom->vProcessMsg.empty();
     }
     CNetMessage &msg(msgs.front());
 
     msg.SetVersion(pfrom->GetRecvVersion());
 
     // Scan for message start
     if (memcmp(std::begin(msg.hdr.pchMessageStart),
                std::begin(chainparams.NetMagic()),
                CMessageHeader::MESSAGE_START_SIZE) != 0) {
         LogPrintf("PROCESSMESSAGE: INVALID MESSAGESTART %s peer=%d\n",
                   SanitizeString(msg.hdr.GetCommand()), pfrom->id);
         pfrom->fDisconnect = true;
         return false;
     }
 
     // Read header
     CMessageHeader &hdr = msg.hdr;
-    if (!hdr.IsValid(chainparams.NetMagic())) {
+    if (!hdr.IsValid(config)) {
         LogPrintf("PROCESSMESSAGE: ERRORS IN HEADER %s peer=%d\n",
                   SanitizeString(hdr.GetCommand()), pfrom->id);
         return fMoreWork;
     }
     std::string strCommand = hdr.GetCommand();
 
     // Message size
     unsigned int nMessageSize = hdr.nMessageSize;
 
     // Checksum
     CDataStream &vRecv = msg.vRecv;
     const uint256 &hash = msg.GetMessageHash();
     if (memcmp(hash.begin(), hdr.pchChecksum, CMessageHeader::CHECKSUM_SIZE) !=
         0) {
         LogPrintf(
             "%s(%s, %u bytes): CHECKSUM ERROR expected %s was %s\n", __func__,
             SanitizeString(strCommand), nMessageSize,
             HexStr(hash.begin(), hash.begin() + CMessageHeader::CHECKSUM_SIZE),
             HexStr(hdr.pchChecksum,
                    hdr.pchChecksum + CMessageHeader::CHECKSUM_SIZE));
         return fMoreWork;
     }
 
     // Process message
     bool fRet = false;
     try {
         fRet = ProcessMessage(config, pfrom, strCommand, vRecv, msg.nTime,
                               chainparams, connman, interruptMsgProc);
         if (interruptMsgProc) {
             return false;
         }
         if (!pfrom->vRecvGetData.empty()) {
             fMoreWork = true;
         }
     } catch (const std::ios_base::failure &e) {
         connman.PushMessage(pfrom,
                             CNetMsgMaker(INIT_PROTO_VERSION)
                                 .Make(NetMsgType::REJECT, strCommand,
                                       REJECT_MALFORMED,
                                       std::string("error parsing message")));
         if (strstr(e.what(), "end of data")) {
             // Allow exceptions from under-length message on vRecv
             LogPrintf(
                 "%s(%s, %u bytes): Exception '%s' caught, normally caused by a "
                 "message being shorter than its stated length\n",
                 __func__, SanitizeString(strCommand), nMessageSize, e.what());
         } else if (strstr(e.what(), "size too large")) {
             // Allow exceptions from over-long size
             LogPrintf("%s(%s, %u bytes): Exception '%s' caught\n", __func__,
                       SanitizeString(strCommand), nMessageSize, e.what());
         } else if (strstr(e.what(), "non-canonical ReadCompactSize()")) {
             // Allow exceptions from non-canonical encoding
             LogPrintf("%s(%s, %u bytes): Exception '%s' caught\n", __func__,
                       SanitizeString(strCommand), nMessageSize, e.what());
         } else {
             PrintExceptionContinue(&e, "ProcessMessages()");
         }
     } catch (const std::exception &e) {
         PrintExceptionContinue(&e, "ProcessMessages()");
     } catch (...) {
         PrintExceptionContinue(nullptr, "ProcessMessages()");
     }
 
     if (!fRet) {
         LogPrintf("%s(%s, %u bytes) FAILED peer=%d\n", __func__,
                   SanitizeString(strCommand), nMessageSize, pfrom->id);
     }
 
     LOCK(cs_main);
     SendRejectsAndCheckIfBanned(pfrom, connman);
 
     return fMoreWork;
 }
 
 class CompareInvMempoolOrder {
     CTxMemPool *mp;
 
 public:
     CompareInvMempoolOrder(CTxMemPool *_mempool) { mp = _mempool; }
 
     bool operator()(std::set<uint256>::iterator a,
                     std::set<uint256>::iterator b) {
         /* As std::make_heap produces a max-heap, we want the entries with the
          * fewest ancestors/highest fee to sort later. */
         return mp->CompareDepthAndScore(*b, *a);
     }
 };
 
 bool SendMessages(const Config &config, CNode *pto, CConnman &connman,
                   const std::atomic<bool> &interruptMsgProc) {
     const Consensus::Params &consensusParams =
         config.GetChainParams().GetConsensus();
 
     // Don't send anything until the version handshake is complete
     if (!pto->fSuccessfullyConnected || pto->fDisconnect) {
         return true;
     }
 
     // If we get here, the outgoing message serialization version is set and
     // can't change.
     const CNetMsgMaker msgMaker(pto->GetSendVersion());
 
     //
     // Message: ping
     //
     bool pingSend = false;
     if (pto->fPingQueued) {
         // RPC ping request by user
         pingSend = true;
     }
     if (pto->nPingNonceSent == 0 &&
         pto->nPingUsecStart + PING_INTERVAL * 1000000 < GetTimeMicros()) {
         // Ping automatically sent as a latency probe & keepalive.
         pingSend = true;
     }
     if (pingSend) {
         uint64_t nonce = 0;
         while (nonce == 0) {
             GetRandBytes((uint8_t *)&nonce, sizeof(nonce));
         }
         pto->fPingQueued = false;
         pto->nPingUsecStart = GetTimeMicros();
         if (pto->nVersion > BIP0031_VERSION) {
             pto->nPingNonceSent = nonce;
             connman.PushMessage(pto, msgMaker.Make(NetMsgType::PING, nonce));
         } else {
             // Peer is too old to support ping command with nonce, pong will
             // never arrive.
             pto->nPingNonceSent = 0;
             connman.PushMessage(pto, msgMaker.Make(NetMsgType::PING));
         }
     }
 
     // Acquire cs_main for IsInitialBlockDownload() and CNodeState()
     TRY_LOCK(cs_main, lockMain);
     if (!lockMain) {
         return true;
     }
 
     if (SendRejectsAndCheckIfBanned(pto, connman)) {
         return true;
     }
     CNodeState &state = *State(pto->GetId());
 
     // Address refresh broadcast
     int64_t nNow = GetTimeMicros();
     if (!IsInitialBlockDownload() && pto->nNextLocalAddrSend < nNow) {
         AdvertiseLocal(pto);
         pto->nNextLocalAddrSend =
             PoissonNextSend(nNow, AVG_LOCAL_ADDRESS_BROADCAST_INTERVAL);
     }
 
     //
     // Message: addr
     //
     if (pto->nNextAddrSend < nNow) {
         pto->nNextAddrSend =
             PoissonNextSend(nNow, AVG_ADDRESS_BROADCAST_INTERVAL);
         std::vector<CAddress> vAddr;
         vAddr.reserve(pto->vAddrToSend.size());
         for (const CAddress &addr : pto->vAddrToSend) {
             if (!pto->addrKnown.contains(addr.GetKey())) {
                 pto->addrKnown.insert(addr.GetKey());
                 vAddr.push_back(addr);
                 // receiver rejects addr messages larger than 1000
                 if (vAddr.size() >= 1000) {
                     connman.PushMessage(pto,
                                         msgMaker.Make(NetMsgType::ADDR, vAddr));
                     vAddr.clear();
                 }
             }
         }
         pto->vAddrToSend.clear();
         if (!vAddr.empty()) {
             connman.PushMessage(pto, msgMaker.Make(NetMsgType::ADDR, vAddr));
         }
 
         // we only send the big addr message once
         if (pto->vAddrToSend.capacity() > 40) {
             pto->vAddrToSend.shrink_to_fit();
         }
     }
 
     // Start block sync
     if (pindexBestHeader == nullptr) {
         pindexBestHeader = chainActive.Tip();
     }
 
     // Download if this is a nice peer, or we have no nice peers and this one
     // might do.
     bool fFetch = state.fPreferredDownload ||
                   (nPreferredDownload == 0 && !pto->fClient && !pto->fOneShot);
 
     if (!state.fSyncStarted && !pto->fClient && !fImporting && !fReindex) {
         // Only actively request headers from a single peer, unless we're close
         // to today.
         if ((nSyncStarted == 0 && fFetch) ||
             pindexBestHeader->GetBlockTime() >
                 GetAdjustedTime() - 24 * 60 * 60) {
             state.fSyncStarted = true;
             nSyncStarted++;
             const CBlockIndex *pindexStart = pindexBestHeader;
             /**
              * If possible, start at the block preceding the currently best
              * known header. This ensures that we always get a non-empty list of
              * headers back as long as the peer is up-to-date. With a non-empty
              * response, we can initialise the peer's known best block. This
              * wouldn't be possible if we requested starting at pindexBestHeader
              * and got back an empty response.
              */
             if (pindexStart->pprev) {
                 pindexStart = pindexStart->pprev;
             }
 
             LogPrint(BCLog::NET,
                      "initial getheaders (%d) to peer=%d (startheight:%d)\n",
                      pindexStart->nHeight, pto->id, pto->nStartingHeight);
             connman.PushMessage(
                 pto,
                 msgMaker.Make(NetMsgType::GETHEADERS,
                               chainActive.GetLocator(pindexStart), uint256()));
         }
     }
 
     // Resend wallet transactions that haven't gotten in a block yet
     // Except during reindex, importing and IBD, when old wallet transactions
     // become unconfirmed and spams other nodes.
     if (!fReindex && !fImporting && !IsInitialBlockDownload()) {
         GetMainSignals().Broadcast(nTimeBestReceived, &connman);
     }
 
     //
     // Try sending block announcements via headers
     //
     {
         // If we have less than MAX_BLOCKS_TO_ANNOUNCE in our list of block
         // hashes we're relaying, and our peer wants headers announcements, then
         // find the first header not yet known to our peer but would connect,
         // and send. If no header would connect, or if we have too many blocks,
         // or if the peer doesn't want headers, just add all to the inv queue.
         LOCK(pto->cs_inventory);
         std::vector<CBlock> vHeaders;
         bool fRevertToInv =
             ((!state.fPreferHeaders &&
               (!state.fPreferHeaderAndIDs ||
                pto->vBlockHashesToAnnounce.size() > 1)) ||
              pto->vBlockHashesToAnnounce.size() > MAX_BLOCKS_TO_ANNOUNCE);
         // last header queued for delivery
         const CBlockIndex *pBestIndex = nullptr;
         // ensure pindexBestKnownBlock is up-to-date
         ProcessBlockAvailability(pto->id);
 
         if (!fRevertToInv) {
             bool fFoundStartingHeader = false;
             // Try to find first header that our peer doesn't have, and then
             // send all headers past that one. If we come across an headers that
             // aren't on chainActive, give up.
             for (const uint256 &hash : pto->vBlockHashesToAnnounce) {
                 BlockMap::iterator mi = mapBlockIndex.find(hash);
                 assert(mi != mapBlockIndex.end());
                 const CBlockIndex *pindex = mi->second;
                 if (chainActive[pindex->nHeight] != pindex) {
                     // Bail out if we reorged away from this block
                     fRevertToInv = true;
                     break;
                 }
                 if (pBestIndex != nullptr && pindex->pprev != pBestIndex) {
                     // This means that the list of blocks to announce don't
                     // connect to each other. This shouldn't really be possible
                     // to hit during regular operation (because reorgs should
                     // take us to a chain that has some block not on the prior
                     // chain, which should be caught by the prior check), but
                     // one way this could happen is by using invalidateblock /
                     // reconsiderblock repeatedly on the tip, causing it to be
                     // added multiple times to vBlockHashesToAnnounce. Robustly
                     // deal with this rare situation by reverting to an inv.
                     fRevertToInv = true;
                     break;
                 }
                 pBestIndex = pindex;
                 if (fFoundStartingHeader) {
                     // add this to the headers message
                     vHeaders.push_back(pindex->GetBlockHeader());
                 } else if (PeerHasHeader(&state, pindex)) {
                     // Keep looking for the first new block.
                     continue;
                 } else if (pindex->pprev == nullptr ||
                            PeerHasHeader(&state, pindex->pprev)) {
                     // Peer doesn't have this header but they do have the prior
                     // one.
                     // Start sending headers.
                     fFoundStartingHeader = true;
                     vHeaders.push_back(pindex->GetBlockHeader());
                 } else {
                     // Peer doesn't have this header or the prior one --
                     // nothing will connect, so bail out.
                     fRevertToInv = true;
                     break;
                 }
             }
         }
         if (!fRevertToInv && !vHeaders.empty()) {
             if (vHeaders.size() == 1 && state.fPreferHeaderAndIDs) {
                 // We only send up to 1 block as header-and-ids, as otherwise
                 // probably means we're doing an initial-ish-sync or they're
                 // slow.
                 LogPrint(BCLog::NET,
                          "%s sending header-and-ids %s to peer=%d\n", __func__,
                          vHeaders.front().GetHash().ToString(), pto->id);
 
                 int nSendFlags = 0;
 
                 bool fGotBlockFromCache = false;
                 {
                     LOCK(cs_most_recent_block);
                     if (most_recent_block_hash == pBestIndex->GetBlockHash()) {
                         CBlockHeaderAndShortTxIDs cmpctblock(
                             *most_recent_block);
                         connman.PushMessage(
                             pto,
                             msgMaker.Make(nSendFlags, NetMsgType::CMPCTBLOCK,
                                           cmpctblock));
                         fGotBlockFromCache = true;
                     }
                 }
                 if (!fGotBlockFromCache) {
                     CBlock block;
                     bool ret = ReadBlockFromDisk(block, pBestIndex, config);
                     assert(ret);
                     CBlockHeaderAndShortTxIDs cmpctblock(block);
                     connman.PushMessage(pto,
                                         msgMaker.Make(nSendFlags,
                                                       NetMsgType::CMPCTBLOCK,
                                                       cmpctblock));
                 }
                 state.pindexBestHeaderSent = pBestIndex;
             } else if (state.fPreferHeaders) {
                 if (vHeaders.size() > 1) {
                     LogPrint(BCLog::NET,
                              "%s: %u headers, range (%s, %s), to peer=%d\n",
                              __func__, vHeaders.size(),
                              vHeaders.front().GetHash().ToString(),
                              vHeaders.back().GetHash().ToString(), pto->id);
                 } else {
                     LogPrint(BCLog::NET, "%s: sending header %s to peer=%d\n",
                              __func__, vHeaders.front().GetHash().ToString(),
                              pto->id);
                 }
                 connman.PushMessage(
                     pto, msgMaker.Make(NetMsgType::HEADERS, vHeaders));
                 state.pindexBestHeaderSent = pBestIndex;
             } else {
                 fRevertToInv = true;
             }
         }
         if (fRevertToInv) {
             // If falling back to using an inv, just try to inv the tip. The
             // last entry in vBlockHashesToAnnounce was our tip at some point in
             // the past.
             if (!pto->vBlockHashesToAnnounce.empty()) {
                 const uint256 &hashToAnnounce =
                     pto->vBlockHashesToAnnounce.back();
                 BlockMap::iterator mi = mapBlockIndex.find(hashToAnnounce);
                 assert(mi != mapBlockIndex.end());
                 const CBlockIndex *pindex = mi->second;
 
                 // Warn if we're announcing a block that is not on the main
                 // chain. This should be very rare and could be optimized out.
                 // Just log for now.
                 if (chainActive[pindex->nHeight] != pindex) {
                     LogPrint(BCLog::NET,
                              "Announcing block %s not on main chain (tip=%s)\n",
                              hashToAnnounce.ToString(),
                              chainActive.Tip()->GetBlockHash().ToString());
                 }
 
                 // If the peer's chain has this block, don't inv it back.
                 if (!PeerHasHeader(&state, pindex)) {
                     pto->PushInventory(CInv(MSG_BLOCK, hashToAnnounce));
                     LogPrint(BCLog::NET, "%s: sending inv peer=%d hash=%s\n",
                              __func__, pto->id, hashToAnnounce.ToString());
                 }
             }
         }
         pto->vBlockHashesToAnnounce.clear();
     }
 
     //
     // Message: inventory
     //
     std::vector<CInv> vInv;
     {
         LOCK(pto->cs_inventory);
         vInv.reserve(std::max<size_t>(pto->vInventoryBlockToSend.size(),
                                       INVENTORY_BROADCAST_MAX));
 
         // Add blocks
         for (const uint256 &hash : pto->vInventoryBlockToSend) {
             vInv.push_back(CInv(MSG_BLOCK, hash));
             if (vInv.size() == MAX_INV_SZ) {
                 connman.PushMessage(pto, msgMaker.Make(NetMsgType::INV, vInv));
                 vInv.clear();
             }
         }
         pto->vInventoryBlockToSend.clear();
 
         // Check whether periodic sends should happen
         bool fSendTrickle = pto->fWhitelisted;
         if (pto->nNextInvSend < nNow) {
             fSendTrickle = true;
             // Use half the delay for outbound peers, as there is less privacy
             // concern for them.
             pto->nNextInvSend = PoissonNextSend(
                 nNow, INVENTORY_BROADCAST_INTERVAL >> !pto->fInbound);
         }
 
         // Time to send but the peer has requested we not relay transactions.
         if (fSendTrickle) {
             LOCK(pto->cs_filter);
             if (!pto->fRelayTxes) {
                 pto->setInventoryTxToSend.clear();
             }
         }
 
         // Respond to BIP35 mempool requests
         if (fSendTrickle && pto->fSendMempool) {
             auto vtxinfo = mempool.infoAll();
             pto->fSendMempool = false;
             Amount filterrate(0);
             {
                 LOCK(pto->cs_feeFilter);
                 filterrate = pto->minFeeFilter;
             }
 
             LOCK(pto->cs_filter);
 
             for (const auto &txinfo : vtxinfo) {
                 const uint256 &txid = txinfo.tx->GetId();
                 CInv inv(MSG_TX, txid);
                 pto->setInventoryTxToSend.erase(txid);
                 if (filterrate != Amount(0)) {
                     if (txinfo.feeRate.GetFeePerK() < filterrate) {
                         continue;
                     }
                 }
                 if (pto->pfilter) {
                     if (!pto->pfilter->IsRelevantAndUpdate(*txinfo.tx)) {
                         continue;
                     }
                 }
                 pto->filterInventoryKnown.insert(txid);
                 vInv.push_back(inv);
                 if (vInv.size() == MAX_INV_SZ) {
                     connman.PushMessage(pto,
                                         msgMaker.Make(NetMsgType::INV, vInv));
                     vInv.clear();
                 }
             }
             pto->timeLastMempoolReq = GetTime();
         }
 
         // Determine transactions to relay
         if (fSendTrickle) {
             // Produce a vector with all candidates for sending
             std::vector<std::set<uint256>::iterator> vInvTx;
             vInvTx.reserve(pto->setInventoryTxToSend.size());
             for (std::set<uint256>::iterator it =
                      pto->setInventoryTxToSend.begin();
                  it != pto->setInventoryTxToSend.end(); it++) {
                 vInvTx.push_back(it);
             }
             Amount filterrate(0);
             {
                 LOCK(pto->cs_feeFilter);
                 filterrate = pto->minFeeFilter;
             }
             // Topologically and fee-rate sort the inventory we send for privacy
             // and priority reasons. A heap is used so that not all items need
             // sorting if only a few are being sent.
             CompareInvMempoolOrder compareInvMempoolOrder(&mempool);
             std::make_heap(vInvTx.begin(), vInvTx.end(),
                            compareInvMempoolOrder);
             // No reason to drain out at many times the network's capacity,
             // especially since we have many peers and some will draw much
             // shorter delays.
             unsigned int nRelayedTransactions = 0;
             LOCK(pto->cs_filter);
             while (!vInvTx.empty() &&
                    nRelayedTransactions < INVENTORY_BROADCAST_MAX) {
                 // Fetch the top element from the heap
                 std::pop_heap(vInvTx.begin(), vInvTx.end(),
                               compareInvMempoolOrder);
                 std::set<uint256>::iterator it = vInvTx.back();
                 vInvTx.pop_back();
                 uint256 hash = *it;
                 // Remove it from the to-be-sent set
                 pto->setInventoryTxToSend.erase(it);
                 // Check if not in the filter already
                 if (pto->filterInventoryKnown.contains(hash)) {
                     continue;
                 }
                 // Not in the mempool anymore? don't bother sending it.
                 auto txinfo = mempool.info(hash);
                 if (!txinfo.tx) {
                     continue;
                 }
                 if (filterrate != Amount(0) &&
                     txinfo.feeRate.GetFeePerK() < filterrate) {
                     continue;
                 }
                 if (pto->pfilter &&
                     !pto->pfilter->IsRelevantAndUpdate(*txinfo.tx)) {
                     continue;
                 }
                 // Send
                 vInv.push_back(CInv(MSG_TX, hash));
                 nRelayedTransactions++;
                 {
                     // Expire old relay messages
                     while (!vRelayExpiration.empty() &&
                            vRelayExpiration.front().first < nNow) {
                         mapRelay.erase(vRelayExpiration.front().second);
                         vRelayExpiration.pop_front();
                     }
 
                     auto ret = mapRelay.insert(
                         std::make_pair(hash, std::move(txinfo.tx)));
                     if (ret.second) {
                         vRelayExpiration.push_back(std::make_pair(
                             nNow + 15 * 60 * 1000000, ret.first));
                     }
                 }
                 if (vInv.size() == MAX_INV_SZ) {
                     connman.PushMessage(pto,
                                         msgMaker.Make(NetMsgType::INV, vInv));
                     vInv.clear();
                 }
                 pto->filterInventoryKnown.insert(hash);
             }
         }
     }
     if (!vInv.empty()) {
         connman.PushMessage(pto, msgMaker.Make(NetMsgType::INV, vInv));
     }
 
     // Detect whether we're stalling
     nNow = GetTimeMicros();
     if (state.nStallingSince &&
         state.nStallingSince < nNow - 1000000 * BLOCK_STALLING_TIMEOUT) {
         // Stalling only triggers when the block download window cannot move.
         // During normal steady state, the download window should be much larger
         // than the to-be-downloaded set of blocks, so disconnection should only
         // happen during initial block download.
         LogPrintf("Peer=%d is stalling block download, disconnecting\n",
                   pto->id);
         pto->fDisconnect = true;
         return true;
     }
     // In case there is a block that has been in flight from this peer for 2 +
     // 0.5 * N times the block interval (with N the number of peers from which
     // we're downloading validated blocks), disconnect due to timeout. We
     // compensate for other peers to prevent killing off peers due to our own
     // downstream link being saturated. We only count validated in-flight blocks
     // so peers can't advertise non-existing block hashes to unreasonably
     // increase our timeout.
     if (state.vBlocksInFlight.size() > 0) {
         QueuedBlock &queuedBlock = state.vBlocksInFlight.front();
         int nOtherPeersWithValidatedDownloads =
             nPeersWithValidatedDownloads -
             (state.nBlocksInFlightValidHeaders > 0);
         if (nNow > state.nDownloadingSince +
                        consensusParams.nPowTargetSpacing *
                            (BLOCK_DOWNLOAD_TIMEOUT_BASE +
                             BLOCK_DOWNLOAD_TIMEOUT_PER_PEER *
                                 nOtherPeersWithValidatedDownloads)) {
             LogPrintf("Timeout downloading block %s from peer=%d, "
                       "disconnecting\n",
                       queuedBlock.hash.ToString(), pto->id);
             pto->fDisconnect = true;
             return true;
         }
     }
 
     //
     // Message: getdata (blocks)
     //
     std::vector<CInv> vGetData;
     if (!pto->fClient && (fFetch || !IsInitialBlockDownload()) &&
         state.nBlocksInFlight < MAX_BLOCKS_IN_TRANSIT_PER_PEER) {
         std::vector<const CBlockIndex *> vToDownload;
         NodeId staller = -1;
         FindNextBlocksToDownload(pto->GetId(),
                                  MAX_BLOCKS_IN_TRANSIT_PER_PEER -
                                      state.nBlocksInFlight,
                                  vToDownload, staller, consensusParams);
         for (const CBlockIndex *pindex : vToDownload) {
             uint32_t nFetchFlags =
                 GetFetchFlags(pto, pindex->pprev, consensusParams);
             vGetData.push_back(
                 CInv(MSG_BLOCK | nFetchFlags, pindex->GetBlockHash()));
             MarkBlockAsInFlight(config, pto->GetId(), pindex->GetBlockHash(),
                                 consensusParams, pindex);
             LogPrint(BCLog::NET, "Requesting block %s (%d) peer=%d\n",
                      pindex->GetBlockHash().ToString(), pindex->nHeight,
                      pto->id);
         }
         if (state.nBlocksInFlight == 0 && staller != -1) {
             if (State(staller)->nStallingSince == 0) {
                 State(staller)->nStallingSince = nNow;
                 LogPrint(BCLog::NET, "Stall started peer=%d\n", staller);
             }
         }
     }
 
     //
     // Message: getdata (non-blocks)
     //
     while (!pto->mapAskFor.empty() && (*pto->mapAskFor.begin()).first <= nNow) {
         const CInv &inv = (*pto->mapAskFor.begin()).second;
         if (!AlreadyHave(inv)) {
             LogPrint(BCLog::NET, "Requesting %s peer=%d\n", inv.ToString(),
                      pto->id);
             vGetData.push_back(inv);
             if (vGetData.size() >= 1000) {
                 connman.PushMessage(
                     pto, msgMaker.Make(NetMsgType::GETDATA, vGetData));
                 vGetData.clear();
             }
         } else {
             // If we're not going to ask, don't expect a response.
             pto->setAskFor.erase(inv.hash);
         }
         pto->mapAskFor.erase(pto->mapAskFor.begin());
     }
     if (!vGetData.empty()) {
         connman.PushMessage(pto, msgMaker.Make(NetMsgType::GETDATA, vGetData));
     }
 
     //
     // Message: feefilter
     //
     // We don't want white listed peers to filter txs to us if we have
     // -whitelistforcerelay
     if (pto->nVersion >= FEEFILTER_VERSION &&
         gArgs.GetBoolArg("-feefilter", DEFAULT_FEEFILTER) &&
         !(pto->fWhitelisted &&
           gArgs.GetBoolArg("-whitelistforcerelay",
                            DEFAULT_WHITELISTFORCERELAY))) {
         Amount currentFilter =
             mempool
                 .GetMinFee(
                     gArgs.GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) *
                     1000000)
                 .GetFeePerK();
         int64_t timeNow = GetTimeMicros();
         if (timeNow > pto->nextSendTimeFeeFilter) {
             static CFeeRate default_feerate =
                 CFeeRate(DEFAULT_MIN_RELAY_TX_FEE);
             static FeeFilterRounder filterRounder(default_feerate);
             Amount filterToSend = filterRounder.round(currentFilter);
             // If we don't allow free transactions, then we always have a fee
             // filter of at least minRelayTxFee
             if (gArgs.GetArg("-limitfreerelay", DEFAULT_LIMITFREERELAY) <= 0) {
                 filterToSend =
                     std::max(filterToSend, ::minRelayTxFee.GetFeePerK());
             }
 
             if (filterToSend != pto->lastSentFeeFilter) {
                 connman.PushMessage(
                     pto, msgMaker.Make(NetMsgType::FEEFILTER, filterToSend));
                 pto->lastSentFeeFilter = filterToSend;
             }
             pto->nextSendTimeFeeFilter =
                 PoissonNextSend(timeNow, AVG_FEEFILTER_BROADCAST_INTERVAL);
         }
         // If the fee filter has changed substantially and it's still more than
         // MAX_FEEFILTER_CHANGE_DELAY until scheduled broadcast, then move the
         // broadcast to within MAX_FEEFILTER_CHANGE_DELAY.
         else if (timeNow + MAX_FEEFILTER_CHANGE_DELAY * 1000000 <
                      pto->nextSendTimeFeeFilter &&
                  (currentFilter < 3 * pto->lastSentFeeFilter / 4 ||
                   currentFilter > 4 * pto->lastSentFeeFilter / 3)) {
             pto->nextSendTimeFeeFilter =
                 timeNow + GetRandInt(MAX_FEEFILTER_CHANGE_DELAY) * 1000000;
         }
     }
     return true;
 }
 
 class CNetProcessingCleanup {
 public:
     CNetProcessingCleanup() {}
     ~CNetProcessingCleanup() {
         // orphan transactions
         mapOrphanTransactions.clear();
         mapOrphanTransactionsByPrev.clear();
     }
 } instance_of_cnetprocessingcleanup;
diff --git a/src/protocol.cpp b/src/protocol.cpp
index f5c97a617..e9947e843 100644
--- a/src/protocol.cpp
+++ b/src/protocol.cpp
@@ -1,181 +1,236 @@
 // Copyright (c) 2009-2010 Satoshi Nakamoto
 // Copyright (c) 2009-2016 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #include "protocol.h"
 
+#include "chainparams.h"
+#include "config.h"
 #include "util.h"
 #include "utilstrencodings.h"
 
 #ifndef WIN32
 #include <arpa/inet.h>
 #endif
 
 namespace NetMsgType {
 const char *VERSION = "version";
 const char *VERACK = "verack";
 const char *ADDR = "addr";
 const char *INV = "inv";
 const char *GETDATA = "getdata";
 const char *MERKLEBLOCK = "merkleblock";
 const char *GETBLOCKS = "getblocks";
 const char *GETHEADERS = "getheaders";
 const char *TX = "tx";
 const char *HEADERS = "headers";
 const char *BLOCK = "block";
 const char *GETADDR = "getaddr";
 const char *MEMPOOL = "mempool";
 const char *PING = "ping";
 const char *PONG = "pong";
 const char *NOTFOUND = "notfound";
 const char *FILTERLOAD = "filterload";
 const char *FILTERADD = "filteradd";
 const char *FILTERCLEAR = "filterclear";
 const char *REJECT = "reject";
 const char *SENDHEADERS = "sendheaders";
 const char *FEEFILTER = "feefilter";
 const char *SENDCMPCT = "sendcmpct";
 const char *CMPCTBLOCK = "cmpctblock";
 const char *GETBLOCKTXN = "getblocktxn";
 const char *BLOCKTXN = "blocktxn";
 
 bool IsBlockLike(const std::string &strCommand) {
     return strCommand == NetMsgType::BLOCK ||
            strCommand == NetMsgType::CMPCTBLOCK ||
            strCommand == NetMsgType::BLOCKTXN;
 }
 }; // namespace NetMsgType
 
 /**
  * All known message types. Keep this in the same order as the list of messages
  * above and in protocol.h.
  */
 static const std::string allNetMessageTypes[] = {
     NetMsgType::VERSION,     NetMsgType::VERACK,     NetMsgType::ADDR,
     NetMsgType::INV,         NetMsgType::GETDATA,    NetMsgType::MERKLEBLOCK,
     NetMsgType::GETBLOCKS,   NetMsgType::GETHEADERS, NetMsgType::TX,
     NetMsgType::HEADERS,     NetMsgType::BLOCK,      NetMsgType::GETADDR,
     NetMsgType::MEMPOOL,     NetMsgType::PING,       NetMsgType::PONG,
     NetMsgType::NOTFOUND,    NetMsgType::FILTERLOAD, NetMsgType::FILTERADD,
     NetMsgType::FILTERCLEAR, NetMsgType::REJECT,     NetMsgType::SENDHEADERS,
     NetMsgType::FEEFILTER,   NetMsgType::SENDCMPCT,  NetMsgType::CMPCTBLOCK,
     NetMsgType::GETBLOCKTXN, NetMsgType::BLOCKTXN,
 };
 static const std::vector<std::string>
     allNetMessageTypesVec(allNetMessageTypes,
                           allNetMessageTypes + ARRAYLEN(allNetMessageTypes));
 
 CMessageHeader::CMessageHeader(const MessageMagic &pchMessageStartIn) {
     memcpy(std::begin(pchMessageStart), std::begin(pchMessageStartIn),
            MESSAGE_START_SIZE);
     memset(pchCommand, 0, sizeof(pchCommand));
     nMessageSize = -1;
     memset(pchChecksum, 0, CHECKSUM_SIZE);
 }
 
 CMessageHeader::CMessageHeader(const MessageMagic &pchMessageStartIn,
                                const char *pszCommand,
                                unsigned int nMessageSizeIn) {
     memcpy(std::begin(pchMessageStart), std::begin(pchMessageStartIn),
            MESSAGE_START_SIZE);
     memset(pchCommand, 0, sizeof(pchCommand));
     strncpy(pchCommand, pszCommand, COMMAND_SIZE);
     nMessageSize = nMessageSizeIn;
     memset(pchChecksum, 0, CHECKSUM_SIZE);
 }
 
 std::string CMessageHeader::GetCommand() const {
     return std::string(pchCommand,
                        pchCommand + strnlen(pchCommand, COMMAND_SIZE));
 }
 
-bool CMessageHeader::IsValid(const MessageMagic &pchMessageStartIn) const {
+static bool
+CheckHeaderMagicAndCommand(const CMessageHeader &header,
+                           const CMessageHeader::MessageMagic &magic) {
     // Check start string
-    if (memcmp(std::begin(pchMessageStart), std::begin(pchMessageStartIn),
-               MESSAGE_START_SIZE) != 0) {
+    if (memcmp(std::begin(header.pchMessageStart), std::begin(magic),
+               CMessageHeader::MESSAGE_START_SIZE) != 0) {
         return false;
     }
 
     // Check the command string for errors
-    for (const char *p1 = pchCommand; p1 < pchCommand + COMMAND_SIZE; p1++) {
+    for (const char *p1 = header.pchCommand;
+         p1 < header.pchCommand + CMessageHeader::COMMAND_SIZE; p1++) {
         if (*p1 == 0) {
             // Must be all zeros after the first zero
-            for (; p1 < pchCommand + COMMAND_SIZE; p1++) {
+            for (; p1 < header.pchCommand + CMessageHeader::COMMAND_SIZE;
+                 p1++) {
                 if (*p1 != 0) {
                     return false;
                 }
             }
         } else if (*p1 < ' ' || *p1 > 0x7E) {
             return false;
         }
     }
 
+    return true;
+}
+
+bool CMessageHeader::IsValid(const Config &config) const {
+    // Check start string
+    if (!CheckHeaderMagicAndCommand(*this,
+                                    config.GetChainParams().NetMagic())) {
+        return false;
+    }
+
     // Message size
-    if (nMessageSize > MAX_SIZE) {
-        LogPrintf("CMessageHeader::IsValid(): (%s, %u bytes) nMessageSize > "
-                  "MAX_SIZE\n",
+    if (IsOversized(config)) {
+        LogPrintf("CMessageHeader::IsValid(): (%s, %u bytes) is oversized\n",
                   GetCommand(), nMessageSize);
         return false;
     }
 
     return true;
 }
 
+/**
+ * This is a transition method in order to stay compatible with older code that
+ * do not use the config. It assumes message will not get too large. This cannot
+ * be used for any piece of code that will download blocks as blocks may be
+ * bigger than the permitted size. Idealy, code that uses this function should
+ * be migrated toward using the config.
+ */
+bool CMessageHeader::IsValidWithoutConfig(const MessageMagic &magic) const {
+    // Check start string
+    if (!CheckHeaderMagicAndCommand(*this, magic)) {
+        return false;
+    }
+
+    // Message size
+    if (nMessageSize > MAX_PROTOCOL_MESSAGE_LENGTH) {
+        LogPrintf(
+            "CMessageHeader::IsValidForSeeder(): (%s, %u bytes) is oversized\n",
+            GetCommand(), nMessageSize);
+        return false;
+    }
+
+    return true;
+}
+
+bool CMessageHeader::IsOversized(const Config &config) const {
+    // If the message doesn't not contain a block content, check against
+    // MAX_PROTOCOL_MESSAGE_LENGTH.
+    if (nMessageSize > MAX_PROTOCOL_MESSAGE_LENGTH &&
+        !NetMsgType::IsBlockLike(GetCommand())) {
+        return true;
+    }
+
+    // Scale the maximum accepted size with the block size.
+    if (nMessageSize > 2 * config.GetMaxBlockSize()) {
+        return true;
+    }
+
+    return false;
+}
+
 CAddress::CAddress() : CService() {
     Init();
 }
 
 CAddress::CAddress(CService ipIn, ServiceFlags nServicesIn) : CService(ipIn) {
     Init();
     nServices = nServicesIn;
 }
 
 void CAddress::Init() {
     nServices = NODE_NONE;
     nTime = 100000000;
 }
 
 CInv::CInv() {
     type = 0;
     hash.SetNull();
 }
 
 CInv::CInv(int typeIn, const uint256 &hashIn) {
     type = typeIn;
     hash = hashIn;
 }
 
 bool operator<(const CInv &a, const CInv &b) {
     return (a.type < b.type || (a.type == b.type && a.hash < b.hash));
 }
 
 std::string CInv::GetCommand() const {
     std::string cmd;
     if (type & MSG_EXT_FLAG) cmd.append("extblk-");
     switch (GetKind()) {
         case MSG_TX:
             return cmd.append(NetMsgType::TX);
         case MSG_BLOCK:
             return cmd.append(NetMsgType::BLOCK);
         case MSG_FILTERED_BLOCK:
             return cmd.append(NetMsgType::MERKLEBLOCK);
         case MSG_CMPCT_BLOCK:
             return cmd.append(NetMsgType::CMPCTBLOCK);
         default:
             throw std::out_of_range(
                 strprintf("CInv::GetCommand(): type=%d unknown type", type));
     }
 }
 
 std::string CInv::ToString() const {
     try {
         return strprintf("%s %s", GetCommand(), hash.ToString());
     } catch (const std::out_of_range &) {
         return strprintf("0x%08x %s", type, hash.ToString());
     }
 }
 
 const std::vector<std::string> &getAllNetMessageTypes() {
     return allNetMessageTypesVec;
 }
diff --git a/src/protocol.h b/src/protocol.h
index 4fbf416a9..32460bdcd 100644
--- a/src/protocol.h
+++ b/src/protocol.h
@@ -1,392 +1,402 @@
 // Copyright (c) 2009-2010 Satoshi Nakamoto
 // Copyright (c) 2009-2016 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #ifndef __cplusplus
 #error This header can only be compiled as C++.
 #endif
 
 #ifndef BITCOIN_PROTOCOL_H
 #define BITCOIN_PROTOCOL_H
 
 #include "netaddress.h"
 #include "serialize.h"
 #include "uint256.h"
 #include "version.h"
 
 #include <array>
 #include <cstdint>
 #include <string>
 
+class Config;
+
+/**
+ * Maximum length of incoming protocol messages (Currently 1MB).
+ * NB: Messages propagating block content are not subject to this limit.
+ */
+static const unsigned int MAX_PROTOCOL_MESSAGE_LENGTH = 1 * 1024 * 1024;
+
 /**
  * Message header.
  * (4) message start.
  * (12) command.
  * (4) size.
  * (4) checksum.
  */
 class CMessageHeader {
 public:
     enum {
         MESSAGE_START_SIZE = 4,
         COMMAND_SIZE = 12,
         MESSAGE_SIZE_SIZE = 4,
         CHECKSUM_SIZE = 4,
 
         MESSAGE_SIZE_OFFSET = MESSAGE_START_SIZE + COMMAND_SIZE,
         CHECKSUM_OFFSET = MESSAGE_SIZE_OFFSET + MESSAGE_SIZE_SIZE,
         HEADER_SIZE = MESSAGE_START_SIZE + COMMAND_SIZE + MESSAGE_SIZE_SIZE +
                       CHECKSUM_SIZE
     };
     typedef std::array<uint8_t, MESSAGE_START_SIZE> MessageMagic;
 
     CMessageHeader(const MessageMagic &pchMessageStartIn);
     CMessageHeader(const MessageMagic &pchMessageStartIn,
                    const char *pszCommand, unsigned int nMessageSizeIn);
 
     std::string GetCommand() const;
-    bool IsValid(const MessageMagic &messageStart) const;
+    bool IsValid(const Config &config) const;
+    bool IsValidWithoutConfig(const MessageMagic &magic) const;
+    bool IsOversized(const Config &config) const;
 
     ADD_SERIALIZE_METHODS;
 
     template <typename Stream, typename Operation>
     inline void SerializationOp(Stream &s, Operation ser_action) {
         READWRITE(FLATDATA(pchMessageStart));
         READWRITE(FLATDATA(pchCommand));
         READWRITE(nMessageSize);
         READWRITE(FLATDATA(pchChecksum));
     }
 
     MessageMagic pchMessageStart;
     char pchCommand[COMMAND_SIZE];
     uint32_t nMessageSize;
     uint8_t pchChecksum[CHECKSUM_SIZE];
 };
 
 /**
  * Bitcoin protocol message types. When adding new message types, don't forget
  * to update allNetMessageTypes in protocol.cpp.
  */
 namespace NetMsgType {
 
 /**
  * The version message provides information about the transmitting node to the
  * receiving node at the beginning of a connection.
  * @see https://bitcoin.org/en/developer-reference#version
  */
 extern const char *VERSION;
 /**
  * The verack message acknowledges a previously-received version message,
  * informing the connecting node that it can begin to send other messages.
  * @see https://bitcoin.org/en/developer-reference#verack
  */
 extern const char *VERACK;
 /**
  * The addr (IP address) message relays connection information for peers on the
  * network.
  * @see https://bitcoin.org/en/developer-reference#addr
  */
 extern const char *ADDR;
 /**
  * The inv message (inventory message) transmits one or more inventories of
  * objects known to the transmitting peer.
  * @see https://bitcoin.org/en/developer-reference#inv
  */
 extern const char *INV;
 /**
  * The getdata message requests one or more data objects from another node.
  * @see https://bitcoin.org/en/developer-reference#getdata
  */
 extern const char *GETDATA;
 /**
  * The merkleblock message is a reply to a getdata message which requested a
  * block using the inventory type MSG_MERKLEBLOCK.
  * @since protocol version 70001 as described by BIP37.
  * @see https://bitcoin.org/en/developer-reference#merkleblock
  */
 extern const char *MERKLEBLOCK;
 /**
  * The getblocks message requests an inv message that provides block header
  * hashes starting from a particular point in the block chain.
  * @see https://bitcoin.org/en/developer-reference#getblocks
  */
 extern const char *GETBLOCKS;
 /**
  * The getheaders message requests a headers message that provides block
  * headers starting from a particular point in the block chain.
  * @since protocol version 31800.
  * @see https://bitcoin.org/en/developer-reference#getheaders
  */
 extern const char *GETHEADERS;
 /**
  * The tx message transmits a single transaction.
  * @see https://bitcoin.org/en/developer-reference#tx
  */
 extern const char *TX;
 /**
  * The headers message sends one or more block headers to a node which
  * previously requested certain headers with a getheaders message.
  * @since protocol version 31800.
  * @see https://bitcoin.org/en/developer-reference#headers
  */
 extern const char *HEADERS;
 /**
  * The block message transmits a single serialized block.
  * @see https://bitcoin.org/en/developer-reference#block
  */
 extern const char *BLOCK;
 /**
  * The getaddr message requests an addr message from the receiving node,
  * preferably one with lots of IP addresses of other receiving nodes.
  * @see https://bitcoin.org/en/developer-reference#getaddr
  */
 extern const char *GETADDR;
 /**
  * The mempool message requests the TXIDs of transactions that the receiving
  * node has verified as valid but which have not yet appeared in a block.
  * @since protocol version 60002.
  * @see https://bitcoin.org/en/developer-reference#mempool
  */
 extern const char *MEMPOOL;
 /**
  * The ping message is sent periodically to help confirm that the receiving
  * peer is still connected.
  * @see https://bitcoin.org/en/developer-reference#ping
  */
 extern const char *PING;
 /**
  * The pong message replies to a ping message, proving to the pinging node that
  * the ponging node is still alive.
  * @since protocol version 60001 as described by BIP31.
  * @see https://bitcoin.org/en/developer-reference#pong
  */
 extern const char *PONG;
 /**
  * The notfound message is a reply to a getdata message which requested an
  * object the receiving node does not have available for relay.
  * @ince protocol version 70001.
  * @see https://bitcoin.org/en/developer-reference#notfound
  */
 extern const char *NOTFOUND;
 /**
  * The filterload message tells the receiving peer to filter all relayed
  * transactions and requested merkle blocks through the provided filter.
  * @since protocol version 70001 as described by BIP37.
  *   Only available with service bit NODE_BLOOM since protocol version
  *   70011 as described by BIP111.
  * @see https://bitcoin.org/en/developer-reference#filterload
  */
 extern const char *FILTERLOAD;
 /**
  * The filteradd message tells the receiving peer to add a single element to a
  * previously-set bloom filter, such as a new public key.
  * @since protocol version 70001 as described by BIP37.
  *   Only available with service bit NODE_BLOOM since protocol version
  *   70011 as described by BIP111.
  * @see https://bitcoin.org/en/developer-reference#filteradd
  */
 extern const char *FILTERADD;
 /**
  * The filterclear message tells the receiving peer to remove a previously-set
  * bloom filter.
  * @since protocol version 70001 as described by BIP37.
  *   Only available with service bit NODE_BLOOM since protocol version
  *   70011 as described by BIP111.
  * @see https://bitcoin.org/en/developer-reference#filterclear
  */
 extern const char *FILTERCLEAR;
 /**
  * The reject message informs the receiving node that one of its previous
  * messages has been rejected.
  * @since protocol version 70002 as described by BIP61.
  * @see https://bitcoin.org/en/developer-reference#reject
  */
 extern const char *REJECT;
 /**
  * Indicates that a node prefers to receive new block announcements via a
  * "headers" message rather than an "inv".
  * @since protocol version 70012 as described by BIP130.
  * @see https://bitcoin.org/en/developer-reference#sendheaders
  */
 extern const char *SENDHEADERS;
 /**
  * The feefilter message tells the receiving peer not to inv us any txs
  * which do not meet the specified min fee rate.
  * @since protocol version 70013 as described by BIP133
  */
 extern const char *FEEFILTER;
 /**
  * Contains a 1-byte bool and 8-byte LE version number.
  * Indicates that a node is willing to provide blocks via "cmpctblock" messages.
  * May indicate that a node prefers to receive new block announcements via a
  * "cmpctblock" message rather than an "inv", depending on message contents.
  * @since protocol version 70014 as described by BIP 152
  */
 extern const char *SENDCMPCT;
 /**
  * Contains a CBlockHeaderAndShortTxIDs object - providing a header and
  * list of "short txids".
  * @since protocol version 70014 as described by BIP 152
  */
 extern const char *CMPCTBLOCK;
 /**
  * Contains a BlockTransactionsRequest
  * Peer should respond with "blocktxn" message.
  * @since protocol version 70014 as described by BIP 152
  */
 extern const char *GETBLOCKTXN;
 /**
  * Contains a BlockTransactions.
  * Sent in response to a "getblocktxn" message.
  * @since protocol version 70014 as described by BIP 152
  */
 extern const char *BLOCKTXN;
 
 /**
  * Indicate if the message is used to transmit the content of a block.
  * These messages can be significantly larger than usual messages and therefore
  * may need to be processed differently.
  */
 bool IsBlockLike(const std::string &strCommand);
 }; // namespace NetMsgType
 
 /* Get a vector of all valid message types (see above) */
 const std::vector<std::string> &getAllNetMessageTypes();
 
 /**
  * nServices flags.
  */
 enum ServiceFlags : uint64_t {
     // Nothing
     NODE_NONE = 0,
     // NODE_NETWORK means that the node is capable of serving the block chain.
     // It is currently set by all Bitcoin ABC nodes, and is unset by SPV clients
     // or other peers that just want network services but don't provide them.
     NODE_NETWORK = (1 << 0),
     // NODE_GETUTXO means the node is capable of responding to the getutxo
     // protocol request. Bitcoin ABC does not support this but a patch set
     // called Bitcoin XT does. See BIP 64 for details on how this is
     // implemented.
     NODE_GETUTXO = (1 << 1),
     // NODE_BLOOM means the node is capable and willing to handle bloom-filtered
     // connections. Bitcoin ABC nodes used to support this by default, without
     // advertising this bit, but no longer do as of protocol version 70011 (=
     // NO_BLOOM_VERSION)
     NODE_BLOOM = (1 << 2),
     // NODE_XTHIN means the node supports Xtreme Thinblocks. If this is turned
     // off then the node will not service nor make xthin requests.
     NODE_XTHIN = (1 << 4),
     // NODE_BITCOIN_CASH means the node supports Bitcoin Cash and the
     // associated consensus rule changes.
     // This service bit is intended to be used prior until some time after the
     // UAHF activation when the Bitcoin Cash network has adequately separated.
     // TODO: remove (free up) the NODE_BITCOIN_CASH service bit once no longer
     // needed.
     NODE_BITCOIN_CASH = (1 << 5),
 
     // Bits 24-31 are reserved for temporary experiments. Just pick a bit that
     // isn't getting used, or one not being used much, and notify the
     // bitcoin-development mailing list. Remember that service bits are just
     // unauthenticated advertisements, so your code must be robust against
     // collisions and other cases where nodes may be advertising a service they
     // do not actually support. Other service bits should be allocated via the
     // BIP process.
 };
 
 /**
  * A CService with information about it as peer.
  */
 class CAddress : public CService {
 public:
     CAddress();
     explicit CAddress(CService ipIn, ServiceFlags nServicesIn);
 
     void Init();
 
     ADD_SERIALIZE_METHODS;
 
     template <typename Stream, typename Operation>
     inline void SerializationOp(Stream &s, Operation ser_action) {
         if (ser_action.ForRead()) Init();
         int nVersion = s.GetVersion();
         if (s.GetType() & SER_DISK) READWRITE(nVersion);
         if ((s.GetType() & SER_DISK) ||
             (nVersion >= CADDR_TIME_VERSION && !(s.GetType() & SER_GETHASH)))
             READWRITE(nTime);
         uint64_t nServicesInt = nServices;
         READWRITE(nServicesInt);
         nServices = (ServiceFlags)nServicesInt;
         READWRITE(*(CService *)this);
     }
 
     // TODO: make private (improves encapsulation)
 public:
     ServiceFlags nServices;
 
     // disk and network only
     unsigned int nTime;
 };
 
 /** getdata message type flags */
 const uint32_t MSG_EXT_FLAG = 1 << 29;
 const uint32_t MSG_TYPE_MASK = 0xffffffff >> 3;
 
 /** getdata / inv message types.
  * These numbers are defined by the protocol. When adding a new value, be sure
  * to mention it in the respective BIP.
  */
 enum GetDataMsg {
     UNDEFINED = 0,
     MSG_TX = 1,
     MSG_BLOCK = 2,
     // The following can only occur in getdata. Invs always use TX or BLOCK.
     //!< Defined in BIP37
     MSG_FILTERED_BLOCK = 3,
     //!< Defined in BIP152
     MSG_CMPCT_BLOCK = 4,
 
     //!< Extension block
     MSG_EXT_TX = MSG_TX | MSG_EXT_FLAG,
     MSG_EXT_BLOCK = MSG_BLOCK | MSG_EXT_FLAG,
 };
 
 /** inv message data */
 class CInv {
 public:
     CInv();
     CInv(int typeIn, const uint256 &hashIn);
 
     ADD_SERIALIZE_METHODS;
 
     template <typename Stream, typename Operation>
     inline void SerializationOp(Stream &s, Operation ser_action) {
         READWRITE(type);
         READWRITE(hash);
     }
 
     friend bool operator<(const CInv &a, const CInv &b);
 
     std::string GetCommand() const;
     std::string ToString() const;
 
     uint32_t GetKind() const { return type & MSG_TYPE_MASK; }
 
     bool IsTx() const {
         auto k = GetKind();
         return k == MSG_TX;
     }
 
     bool IsSomeBlock() const {
         auto k = GetKind();
         return k == MSG_BLOCK || k == MSG_FILTERED_BLOCK ||
                k == MSG_CMPCT_BLOCK;
     }
 
     // TODO: make private (improves encapsulation)
 public:
     int type;
     uint256 hash;
 };
 
 #endif // BITCOIN_PROTOCOL_H
diff --git a/src/seeder/bitcoin.cpp b/src/seeder/bitcoin.cpp
index 5ab0e8c16..d0e7cf7e5 100644
--- a/src/seeder/bitcoin.cpp
+++ b/src/seeder/bitcoin.cpp
@@ -1,340 +1,340 @@
 #include "bitcoin.h"
 
 #include "db.h"
 #include "hash.h"
 #include "netbase.h"
 #include "serialize.h"
 #include "streams.h"
 #include "uint256.h"
 
 #include <algorithm>
 
 // Weither we are on testnet or mainnet.
 bool fTestNet;
 
 // The network magic to use.
 CMessageHeader::MessageMagic netMagic = {0xe3, 0xe1, 0xf3, 0xe8};
 
 #define BITCOIN_SEED_NONCE 0x0539a019ca550825ULL
 
 static const uint32_t allones(-1);
 
 class CSeederNode {
     SOCKET sock;
     CDataStream vSend;
     CDataStream vRecv;
     uint32_t nHeaderStart;
     uint32_t nMessageStart;
     int nVersion;
     std::string strSubVer;
     int nStartingHeight;
     std::vector<CAddress> *vAddr;
     int ban;
     int64_t doneAfter;
     CAddress you;
 
     int GetTimeout() { return you.IsTor() ? 120 : 30; }
 
     void BeginMessage(const char *pszCommand) {
         if (nHeaderStart != allones) {
             AbortMessage();
         }
         nHeaderStart = vSend.size();
         vSend << CMessageHeader(netMagic, pszCommand, 0);
         nMessageStart = vSend.size();
         //    printf("%s: SEND %s\n", ToString(you).c_str(), pszCommand);
     }
 
     void AbortMessage() {
         if (nHeaderStart == allones) {
             return;
         }
         vSend.resize(nHeaderStart);
         nHeaderStart = allones;
         nMessageStart = allones;
     }
 
     void EndMessage() {
         if (nHeaderStart == allones) {
             return;
         }
         uint32_t nSize = vSend.size() - nMessageStart;
         memcpy((char *)&vSend[nHeaderStart] +
                    offsetof(CMessageHeader, nMessageSize),
                &nSize, sizeof(nSize));
         if (vSend.GetVersion() >= 209) {
             uint256 hash = Hash(vSend.begin() + nMessageStart, vSend.end());
             unsigned int nChecksum = 0;
             memcpy(&nChecksum, &hash, sizeof(nChecksum));
             assert(nMessageStart - nHeaderStart >=
                    offsetof(CMessageHeader, pchChecksum) + sizeof(nChecksum));
             memcpy((char *)&vSend[nHeaderStart] +
                        offsetof(CMessageHeader, pchChecksum),
                    &nChecksum, sizeof(nChecksum));
         }
         nHeaderStart = allones;
         nMessageStart = allones;
     }
 
     void Send() {
         if (sock == INVALID_SOCKET) {
             return;
         }
         if (vSend.empty()) {
             return;
         }
         int nBytes = send(sock, &vSend[0], vSend.size(), 0);
         if (nBytes > 0) {
             vSend.erase(vSend.begin(), vSend.begin() + nBytes);
         } else {
             close(sock);
             sock = INVALID_SOCKET;
         }
     }
 
     void PushVersion() {
         int64_t nTime = time(nullptr);
         uint64_t nLocalNonce = BITCOIN_SEED_NONCE;
         int64_t nLocalServices = 0;
         CService myService;
         CAddress me(myService, ServiceFlags(NODE_NETWORK | NODE_BITCOIN_CASH));
         BeginMessage("version");
         int nBestHeight = GetRequireHeight();
         std::string ver = "/bitcoin-cash-seeder:0.15/";
         vSend << PROTOCOL_VERSION << nLocalServices << nTime << you << me
               << nLocalNonce << ver << nBestHeight;
         EndMessage();
     }
 
     void GotVersion() {
         // printf("\n%s: version %i\n", ToString(you).c_str(), nVersion);
         if (vAddr) {
             BeginMessage("getaddr");
             EndMessage();
             doneAfter = time(nullptr) + GetTimeout();
         } else {
             doneAfter = time(nullptr) + 1;
         }
     }
 
     bool ProcessMessage(std::string strCommand, CDataStream &vRecv) {
         //    printf("%s: RECV %s\n", ToString(you).c_str(),
         //    strCommand.c_str());
         if (strCommand == "version") {
             int64_t nTime;
             CAddress addrMe;
             CAddress addrFrom;
             uint64_t nNonce = 1;
             uint64_t nServiceInt;
             vRecv >> nVersion >> nServiceInt >> nTime >> addrMe;
             you.nServices = ServiceFlags(nServiceInt);
             if (nVersion == 10300) nVersion = 300;
             if (nVersion >= 106 && !vRecv.empty()) vRecv >> addrFrom >> nNonce;
             if (nVersion >= 106 && !vRecv.empty()) vRecv >> strSubVer;
             if (nVersion >= 209 && !vRecv.empty()) vRecv >> nStartingHeight;
 
             if (nVersion >= 209) {
                 BeginMessage("verack");
                 EndMessage();
             }
             vSend.SetVersion(std::min(nVersion, PROTOCOL_VERSION));
             if (nVersion < 209) {
                 this->vRecv.SetVersion(std::min(nVersion, PROTOCOL_VERSION));
                 GotVersion();
             }
             return false;
         }
 
         if (strCommand == "verack") {
             this->vRecv.SetVersion(std::min(nVersion, PROTOCOL_VERSION));
             GotVersion();
             return false;
         }
 
         if (strCommand == "addr" && vAddr) {
             std::vector<CAddress> vAddrNew;
             vRecv >> vAddrNew;
             // printf("%s: got %i addresses\n", ToString(you).c_str(),
             // (int)vAddrNew.size());
             int64_t now = time(nullptr);
             std::vector<CAddress>::iterator it = vAddrNew.begin();
             if (vAddrNew.size() > 1) {
                 if (doneAfter == 0 || doneAfter > now + 1) doneAfter = now + 1;
             }
             while (it != vAddrNew.end()) {
                 CAddress &addr = *it;
                 //        printf("%s: got address %s\n", ToString(you).c_str(),
                 //        addr.ToString().c_str(), (int)(vAddr->size()));
                 it++;
                 if (addr.nTime <= 100000000 || addr.nTime > now + 600)
                     addr.nTime = now - 5 * 86400;
                 if (addr.nTime > now - 604800) vAddr->push_back(addr);
                 //        printf("%s: added address %s (#%i)\n",
                 //        ToString(you).c_str(), addr.ToString().c_str(),
                 //        (int)(vAddr->size()));
                 if (vAddr->size() > 1000) {
                     doneAfter = 1;
                     return true;
                 }
             }
             return false;
         }
 
         return false;
     }
 
     bool ProcessMessages() {
         if (vRecv.empty()) {
             return false;
         }
 
         do {
             CDataStream::iterator pstart = std::search(
                 vRecv.begin(), vRecv.end(), BEGIN(netMagic), END(netMagic));
             uint32_t nHeaderSize = GetSerializeSize(
                 CMessageHeader(netMagic), vRecv.GetType(), vRecv.GetVersion());
             if (vRecv.end() - pstart < nHeaderSize) {
                 if (vRecv.size() > nHeaderSize) {
                     vRecv.erase(vRecv.begin(), vRecv.end() - nHeaderSize);
                 }
                 break;
             }
             vRecv.erase(vRecv.begin(), pstart);
             std::vector<char> vHeaderSave(vRecv.begin(),
                                           vRecv.begin() + nHeaderSize);
             CMessageHeader hdr(netMagic);
             vRecv >> hdr;
-            if (!hdr.IsValid(netMagic)) {
+            if (!hdr.IsValidWithoutConfig(netMagic)) {
                 // printf("%s: BAD (invalid header)\n", ToString(you).c_str());
                 ban = 100000;
                 return true;
             }
             std::string strCommand = hdr.GetCommand();
             unsigned int nMessageSize = hdr.nMessageSize;
             if (nMessageSize > MAX_SIZE) {
                 // printf("%s: BAD (message too large)\n",
                 // ToString(you).c_str());
                 ban = 100000;
                 return true;
             }
             if (nMessageSize > vRecv.size()) {
                 vRecv.insert(vRecv.begin(), vHeaderSave.begin(),
                              vHeaderSave.end());
                 break;
             }
             if (vRecv.GetVersion() >= 209) {
                 uint256 hash =
                     Hash(vRecv.begin(), vRecv.begin() + nMessageSize);
                 if (memcmp(hash.begin(), hdr.pchChecksum,
                            CMessageHeader::CHECKSUM_SIZE) != 0) {
                     continue;
                 }
             }
             CDataStream vMsg(vRecv.begin(), vRecv.begin() + nMessageSize,
                              vRecv.GetType(), vRecv.GetVersion());
             vRecv.ignore(nMessageSize);
             if (ProcessMessage(strCommand, vMsg)) return true;
             //      printf("%s: done processing %s\n", ToString(you).c_str(),
             //      strCommand.c_str());
         } while (1);
         return false;
     }
 
 public:
     CSeederNode(const CService &ip, std::vector<CAddress> *vAddrIn)
         : vSend(SER_NETWORK, 0), vRecv(SER_NETWORK, 0), nHeaderStart(-1),
           nMessageStart(-1), nVersion(0), vAddr(vAddrIn), ban(0), doneAfter(0),
           you(ip, ServiceFlags(NODE_NETWORK | NODE_BITCOIN_CASH)) {
         if (time(nullptr) > 1329696000) {
             vSend.SetVersion(209);
             vRecv.SetVersion(209);
         }
     }
 
     bool Run() {
         bool proxyConnectionFailed = false;
         if (!ConnectSocket(you, sock, nConnectTimeout,
                            &proxyConnectionFailed)) {
             return false;
         }
 
         PushVersion();
         Send();
 
         bool res = true;
         int64_t now;
         while (now = time(nullptr),
                ban == 0 && (doneAfter == 0 || doneAfter > now) &&
                    sock != INVALID_SOCKET) {
             char pchBuf[0x10000];
             fd_set set;
             FD_ZERO(&set);
             FD_SET(sock, &set);
             struct timeval wa;
             if (doneAfter) {
                 wa.tv_sec = doneAfter - now;
                 wa.tv_usec = 0;
             } else {
                 wa.tv_sec = GetTimeout();
                 wa.tv_usec = 0;
             }
             int ret = select(sock + 1, &set, nullptr, &set, &wa);
             if (ret != 1) {
                 if (!doneAfter) res = false;
                 break;
             }
             int nBytes = recv(sock, pchBuf, sizeof(pchBuf), 0);
             int nPos = vRecv.size();
             if (nBytes > 0) {
                 vRecv.resize(nPos + nBytes);
                 memcpy(&vRecv[nPos], pchBuf, nBytes);
             } else if (nBytes == 0) {
                 // printf("%s: BAD (connection closed prematurely)\n",
                 // ToString(you).c_str());
                 res = false;
                 break;
             } else {
                 // printf("%s: BAD (connection error)\n",
                 // ToString(you).c_str());
                 res = false;
                 break;
             }
             ProcessMessages();
             Send();
         }
         if (sock == INVALID_SOCKET) res = false;
         close(sock);
         sock = INVALID_SOCKET;
         return (ban == 0) && res;
     }
 
     int GetBan() { return ban; }
 
     int GetClientVersion() { return nVersion; }
 
     std::string GetClientSubVersion() { return strSubVer; }
 
     int GetStartingHeight() { return nStartingHeight; }
 };
 
 bool TestNode(const CService &cip, int &ban, int &clientV,
               std::string &clientSV, int &blocks,
               std::vector<CAddress> *vAddr) {
     try {
         CSeederNode node(cip, vAddr);
         bool ret = node.Run();
         if (!ret) {
             ban = node.GetBan();
         } else {
             ban = 0;
         }
         clientV = node.GetClientVersion();
         clientSV = node.GetClientSubVersion();
         blocks = node.GetStartingHeight();
         //  printf("%s: %s!!!\n", cip.ToString().c_str(), ret ? "GOOD" : "BAD");
         return ret;
     } catch (std::ios_base::failure &e) {
         ban = 0;
         return false;
     }
 }
diff --git a/src/test/test_bitcoin_fuzzy.cpp b/src/test/test_bitcoin_fuzzy.cpp
index 61016d967..e868a262a 100644
--- a/src/test/test_bitcoin_fuzzy.cpp
+++ b/src/test/test_bitcoin_fuzzy.cpp
@@ -1,259 +1,259 @@
 // Copyright (c) 2009-2016 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
 #if defined(HAVE_CONFIG_H)
 #include "config/bitcoin-config.h"
 #endif
 
 #include "addrman.h"
 #include "chain.h"
 #include "coins.h"
 #include "compressor.h"
 #include "consensus/merkle.h"
 #include "net.h"
 #include "primitives/block.h"
 #include "protocol.h"
 #include "pubkey.h"
 #include "script/script.h"
 #include "streams.h"
 #include "undo.h"
 #include "version.h"
 
 #include <cstdint>
 #include <unistd.h>
 
 #include <algorithm>
 #include <vector>
 
 enum TEST_ID {
     CBLOCK_DESERIALIZE = 0,
     CTRANSACTION_DESERIALIZE,
     CBLOCKLOCATOR_DESERIALIZE,
     CBLOCKMERKLEROOT,
     CADDRMAN_DESERIALIZE,
     CBLOCKHEADER_DESERIALIZE,
     CBANENTRY_DESERIALIZE,
     CTXUNDO_DESERIALIZE,
     CBLOCKUNDO_DESERIALIZE,
     COIN_DESERIALIZE,
     CNETADDR_DESERIALIZE,
     CSERVICE_DESERIALIZE,
     CMESSAGEHEADER_DESERIALIZE,
     CADDRESS_DESERIALIZE,
     CINV_DESERIALIZE,
     CBLOOMFILTER_DESERIALIZE,
     CDISKBLOCKINDEX_DESERIALIZE,
     CTXOUTCOMPRESSOR_DESERIALIZE,
     TEST_ID_END
 };
 
 bool read_stdin(std::vector<char> &data) {
     char buffer[1024];
     ssize_t length = 0;
     while ((length = read(STDIN_FILENO, buffer, 1024)) > 0) {
         data.insert(data.end(), buffer, buffer + length);
 
         if (data.size() > (1 << 20)) return false;
     }
     return length == 0;
 }
 
 int main(int argc, char **argv) {
     ECCVerifyHandle globalVerifyHandle;
     std::vector<char> buffer;
     if (!read_stdin(buffer)) return 0;
 
     if (buffer.size() < sizeof(uint32_t)) return 0;
 
     uint32_t test_id = 0xffffffff;
     memcpy(&test_id, &buffer[0], sizeof(uint32_t));
     buffer.erase(buffer.begin(), buffer.begin() + sizeof(uint32_t));
 
     if (test_id >= TEST_ID_END) return 0;
 
     CDataStream ds(buffer, SER_NETWORK, INIT_PROTO_VERSION);
     try {
         int nVersion;
         ds >> nVersion;
         ds.SetVersion(nVersion);
     } catch (const std::ios_base::failure &e) {
         return 0;
     }
 
     switch (test_id) {
         case CBLOCK_DESERIALIZE: {
             try {
                 CBlock block;
                 ds >> block;
             } catch (const std::ios_base::failure &e) {
                 return 0;
             }
             break;
         }
         case CTRANSACTION_DESERIALIZE: {
             try {
                 CTransaction tx(deserialize, ds);
             } catch (const std::ios_base::failure &e) {
                 return 0;
             }
             break;
         }
         case CBLOCKLOCATOR_DESERIALIZE: {
             try {
                 CBlockLocator bl;
                 ds >> bl;
             } catch (const std::ios_base::failure &e) {
                 return 0;
             }
             break;
         }
         case CBLOCKMERKLEROOT: {
             try {
                 CBlock block;
                 ds >> block;
                 bool mutated;
                 BlockMerkleRoot(block, &mutated);
             } catch (const std::ios_base::failure &e) {
                 return 0;
             }
             break;
         }
         case CADDRMAN_DESERIALIZE: {
             try {
                 CAddrMan am;
                 ds >> am;
             } catch (const std::ios_base::failure &e) {
                 return 0;
             }
             break;
         }
         case CBLOCKHEADER_DESERIALIZE: {
             try {
                 CBlockHeader bh;
                 ds >> bh;
             } catch (const std::ios_base::failure &e) {
                 return 0;
             }
             break;
         }
         case CBANENTRY_DESERIALIZE: {
             try {
                 CBanEntry be;
                 ds >> be;
             } catch (const std::ios_base::failure &e) {
                 return 0;
             }
             break;
         }
         case CTXUNDO_DESERIALIZE: {
             try {
                 CTxUndo tu;
                 ds >> tu;
             } catch (const std::ios_base::failure &e) {
                 return 0;
             }
             break;
         }
         case CBLOCKUNDO_DESERIALIZE: {
             try {
                 CBlockUndo bu;
                 ds >> bu;
             } catch (const std::ios_base::failure &e) {
                 return 0;
             }
             break;
         }
         case COIN_DESERIALIZE: {
             try {
                 Coin coin;
                 ds >> coin;
             } catch (const std::ios_base::failure &e) {
                 return 0;
             }
             break;
         }
         case CNETADDR_DESERIALIZE: {
             try {
                 CNetAddr na;
                 ds >> na;
             } catch (const std::ios_base::failure &e) {
                 return 0;
             }
             break;
         }
         case CSERVICE_DESERIALIZE: {
             try {
                 CService s;
                 ds >> s;
             } catch (const std::ios_base::failure &e) {
                 return 0;
             }
             break;
         }
         case CMESSAGEHEADER_DESERIALIZE: {
             CMessageHeader::MessageMagic pchMessageStart = {0x00, 0x00, 0x00,
                                                             0x00};
             try {
                 CMessageHeader mh(pchMessageStart);
                 ds >> mh;
-                if (!mh.IsValid(pchMessageStart)) {
+                if (!mh.IsValidWithoutConfig(pchMessageStart)) {
                     return 0;
                 }
             } catch (const std::ios_base::failure &e) {
                 return 0;
             }
             break;
         }
         case CADDRESS_DESERIALIZE: {
             try {
                 CAddress a;
                 ds >> a;
             } catch (const std::ios_base::failure &e) {
                 return 0;
             }
             break;
         }
         case CINV_DESERIALIZE: {
             try {
                 CInv i;
                 ds >> i;
             } catch (const std::ios_base::failure &e) {
                 return 0;
             }
             break;
         }
         case CBLOOMFILTER_DESERIALIZE: {
             try {
                 CBloomFilter bf;
                 ds >> bf;
             } catch (const std::ios_base::failure &e) {
                 return 0;
             }
             break;
         }
         case CDISKBLOCKINDEX_DESERIALIZE: {
             try {
                 CDiskBlockIndex dbi;
                 ds >> dbi;
             } catch (const std::ios_base::failure &e) {
                 return 0;
             }
             break;
         }
         case CTXOUTCOMPRESSOR_DESERIALIZE: {
             CTxOut to;
             CTxOutCompressor toc(to);
             try {
                 ds >> toc;
             } catch (const std::ios_base::failure &e) {
                 return 0;
             }
 
             break;
         }
         default:
             return 0;
     }
     return 0;
 }
diff --git a/test/functional/abc-p2p-fullblocktest.py b/test/functional/abc-p2p-fullblocktest.py
index 79c455545..737a7b0e9 100755
--- a/test/functional/abc-p2p-fullblocktest.py
+++ b/test/functional/abc-p2p-fullblocktest.py
@@ -1,504 +1,504 @@
 #!/usr/bin/env python3
 # Copyright (c) 2015-2016 The Bitcoin Core developers
 # Copyright (c) 2017 The Bitcoin developers
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 """
 This test checks simple acceptance of bigger blocks via p2p.
 It is derived from the much more complex p2p-fullblocktest.
 The intention is that small tests can be derived from this one, or
 this one can be extended, to cover the checks done for bigger blocks
 (e.g. sigops limits).
 """
 
 from test_framework.test_framework import ComparisonTestFramework
 from test_framework.util import *
 from test_framework.comptool import TestManager, TestInstance, RejectResult
 from test_framework.blocktools import *
 import time
 from test_framework.key import CECKey
 from test_framework.script import *
 from test_framework.cdefs import (ONE_MEGABYTE, LEGACY_MAX_BLOCK_SIZE,
                                   MAX_BLOCK_SIGOPS_PER_MB, MAX_TX_SIGOPS_COUNT)
 
 
 class PreviousSpendableOutput():
 
     def __init__(self, tx=CTransaction(), n=-1):
         self.tx = tx
         self.n = n  # the output we're spending
 
 
 # TestNode: A peer we use to send messages to bitcoind, and store responses.
 class TestNode(NodeConnCB):
 
     def __init__(self):
         self.last_sendcmpct = None
         self.last_cmpctblock = None
         self.last_getheaders = None
         self.last_headers = None
         super().__init__()
 
     def on_sendcmpct(self, conn, message):
         self.last_sendcmpct = message
 
     def on_cmpctblock(self, conn, message):
         self.last_cmpctblock = message
         self.last_cmpctblock.header_and_shortids.header.calc_sha256()
 
     def on_getheaders(self, conn, message):
         self.last_getheaders = message
 
     def on_headers(self, conn, message):
         self.last_headers = message
         for x in self.last_headers.headers:
             x.calc_sha256()
 
     def clear_block_data(self):
         with mininode_lock:
             self.last_sendcmpct = None
             self.last_cmpctblock = None
 
 
 class FullBlockTest(ComparisonTestFramework):
 
     # Can either run this test as 1 node with expected answers, or two and compare them.
     # Change the "outcome" variable from each TestInstance object to only do
     # the comparison.
 
     def set_test_params(self):
         self.num_nodes = 1
         self.setup_clean_chain = True
         self.block_heights = {}
         self.coinbase_key = CECKey()
         self.coinbase_key.set_secretbytes(b"fatstacks")
         self.coinbase_pubkey = self.coinbase_key.get_pubkey()
         self.tip = None
         self.blocks = {}
-        self.excessive_block_size = 32 * ONE_MEGABYTE
+        self.excessive_block_size = 64 * ONE_MEGABYTE
         self.extra_args = [['-norelaypriority',
                             '-whitelist=127.0.0.1',
                             '-limitancestorcount=9999',
                             '-limitancestorsize=9999',
                             '-limitdescendantcount=9999',
                             '-limitdescendantsize=9999',
                             '-maxmempool=999',
                             "-excessiveblocksize=%d"
                             % self.excessive_block_size]]
 
     def add_options(self, parser):
         super().add_options(parser)
         parser.add_option(
             "--runbarelyexpensive", dest="runbarelyexpensive", default=True)
 
     def run_test(self):
         self.test = TestManager(self, self.options.tmpdir)
         self.test.add_all_connections(self.nodes)
         # Start up network handling in another thread
         NetworkThread().start()
         # Set the blocksize to 2MB as initial condition
         self.nodes[0].setexcessiveblock(self.excessive_block_size)
         self.test.run()
 
     def add_transactions_to_block(self, block, tx_list):
         [tx.rehash() for tx in tx_list]
         block.vtx.extend(tx_list)
 
     # this is a little handier to use than the version in blocktools.py
     def create_tx(self, spend_tx, n, value, script=CScript([OP_TRUE])):
         tx = create_transaction(spend_tx, n, b"", value, script)
         return tx
 
     # sign a transaction, using the key we know about
     # this signs input 0 in tx, which is assumed to be spending output n in
     # spend_tx
     def sign_tx(self, tx, spend_tx, n):
         scriptPubKey = bytearray(spend_tx.vout[n].scriptPubKey)
         if (scriptPubKey[0] == OP_TRUE):  # an anyone-can-spend
             tx.vin[0].scriptSig = CScript()
             return
         sighash = SignatureHashForkId(
             spend_tx.vout[n].scriptPubKey, tx, 0, SIGHASH_ALL | SIGHASH_FORKID, spend_tx.vout[n].nValue)
         tx.vin[0].scriptSig = CScript(
             [self.coinbase_key.sign(sighash) + bytes(bytearray([SIGHASH_ALL | SIGHASH_FORKID]))])
 
     def create_and_sign_transaction(self, spend_tx, n, value, script=CScript([OP_TRUE])):
         tx = self.create_tx(spend_tx, n, value, script)
         self.sign_tx(tx, spend_tx, n)
         tx.rehash()
         return tx
 
     def next_block(self, number, spend=None, additional_coinbase_value=0, script=None, extra_sigops=0, block_size=0, solve=True):
         """
         Create a block on top of self.tip, and advance self.tip to point to the new block
         if spend is specified, then 1 satoshi will be spent from that to an anyone-can-spend
         output, and rest will go to fees.
         """
         if self.tip == None:
             base_block_hash = self.genesis_hash
             block_time = int(time.time()) + 1
         else:
             base_block_hash = self.tip.sha256
             block_time = self.tip.nTime + 1
         # First create the coinbase
         height = self.block_heights[base_block_hash] + 1
         coinbase = create_coinbase(height, self.coinbase_pubkey)
         coinbase.vout[0].nValue += additional_coinbase_value
         if (spend != None):
             coinbase.vout[0].nValue += spend.tx.vout[
                 spend.n].nValue - 1  # all but one satoshi to fees
         coinbase.rehash()
         block = create_block(base_block_hash, coinbase, block_time)
         spendable_output = None
         if (spend != None):
             tx = CTransaction()
             # no signature yet
             tx.vin.append(
                 CTxIn(COutPoint(spend.tx.sha256, spend.n), b"", 0xffffffff))
             # We put some random data into the first transaction of the chain
             # to randomize ids
             tx.vout.append(
                 CTxOut(0, CScript([random.randint(0, 255), OP_DROP, OP_TRUE])))
             if script == None:
                 tx.vout.append(CTxOut(1, CScript([OP_TRUE])))
             else:
                 tx.vout.append(CTxOut(1, script))
             spendable_output = PreviousSpendableOutput(tx, 0)
 
             # Now sign it if necessary
             scriptSig = b""
             scriptPubKey = bytearray(spend.tx.vout[spend.n].scriptPubKey)
             if (scriptPubKey[0] == OP_TRUE):  # looks like an anyone-can-spend
                 scriptSig = CScript([OP_TRUE])
             else:
                 # We have to actually sign it
                 sighash = SignatureHashForkId(
                     spend.tx.vout[spend.n].scriptPubKey, tx, 0, SIGHASH_ALL | SIGHASH_FORKID, spend.tx.vout[spend.n].nValue)
                 scriptSig = CScript(
                     [self.coinbase_key.sign(sighash) + bytes(bytearray([SIGHASH_ALL | SIGHASH_FORKID]))])
             tx.vin[0].scriptSig = scriptSig
             # Now add the transaction to the block
             self.add_transactions_to_block(block, [tx])
             block.hashMerkleRoot = block.calc_merkle_root()
         if spendable_output != None and block_size > 0:
             while len(block.serialize()) < block_size:
                 tx = CTransaction()
                 script_length = block_size - len(block.serialize()) - 79
                 if script_length > 510000:
                     script_length = 500000
                 tx_sigops = min(
                     extra_sigops, script_length, MAX_TX_SIGOPS_COUNT)
                 extra_sigops -= tx_sigops
                 script_pad_len = script_length - tx_sigops
                 script_output = CScript(
                     [b'\x00' * script_pad_len] + [OP_CHECKSIG] * tx_sigops)
                 tx.vout.append(CTxOut(0, CScript([OP_TRUE])))
                 tx.vout.append(CTxOut(0, script_output))
                 tx.vin.append(
                     CTxIn(COutPoint(spendable_output.tx.sha256, spendable_output.n)))
                 spendable_output = PreviousSpendableOutput(tx, 0)
                 self.add_transactions_to_block(block, [tx])
             block.hashMerkleRoot = block.calc_merkle_root()
             # Make sure the math above worked out to produce the correct block size
             # (the math will fail if there are too many transactions in the block)
             assert_equal(len(block.serialize()), block_size)
             # Make sure all the requested sigops have been included
             assert_equal(extra_sigops, 0)
         if solve:
             block.solve()
         self.tip = block
         self.block_heights[block.sha256] = height
         assert number not in self.blocks
         self.blocks[number] = block
         return block
 
     def get_tests(self):
         self.genesis_hash = int(self.nodes[0].getbestblockhash(), 16)
         self.block_heights[self.genesis_hash] = 0
         spendable_outputs = []
 
         # save the current tip so it can be spent by a later block
         def save_spendable_output():
             spendable_outputs.append(self.tip)
 
         # get an output that we previously marked as spendable
         def get_spendable_output():
             return PreviousSpendableOutput(spendable_outputs.pop(0).vtx[0], 0)
 
         # returns a test case that asserts that the current tip was accepted
         def accepted():
             return TestInstance([[self.tip, True]])
 
         # returns a test case that asserts that the current tip was rejected
         def rejected(reject=None):
             if reject is None:
                 return TestInstance([[self.tip, False]])
             else:
                 return TestInstance([[self.tip, reject]])
 
         # move the tip back to a previous block
         def tip(number):
             self.tip = self.blocks[number]
 
         # adds transactions to the block and updates state
         def update_block(block_number, new_transactions):
             block = self.blocks[block_number]
             self.add_transactions_to_block(block, new_transactions)
             old_sha256 = block.sha256
             block.hashMerkleRoot = block.calc_merkle_root()
             block.solve()
             # Update the internal state just like in next_block
             self.tip = block
             if block.sha256 != old_sha256:
                 self.block_heights[
                     block.sha256] = self.block_heights[old_sha256]
                 del self.block_heights[old_sha256]
             self.blocks[block_number] = block
             return block
 
         # shorthand for functions
         block = self.next_block
 
         # Create a new block
         block(0)
         save_spendable_output()
         yield accepted()
 
         # Now we need that block to mature so we can spend the coinbase.
         test = TestInstance(sync_every_block=False)
         for i in range(99):
             block(5000 + i)
             test.blocks_and_transactions.append([self.tip, True])
             save_spendable_output()
         yield test
 
         # collect spendable outputs now to avoid cluttering the code later on
         out = []
         for i in range(100):
             out.append(get_spendable_output())
 
         # Let's build some blocks and test them.
         for i in range(16):
             n = i + 1
             block(n, spend=out[i], block_size=n * ONE_MEGABYTE)
             yield accepted()
 
         # block of maximal size
         block(17, spend=out[16], block_size=self.excessive_block_size)
         yield accepted()
 
         # Reject oversized blocks with bad-blk-length error
         block(18, spend=out[17], block_size=self.excessive_block_size + 1)
         yield rejected(RejectResult(16, b'bad-blk-length'))
 
         # Rewind bad block.
         tip(17)
 
         # Accept many sigops
         lots_of_checksigs = CScript(
             [OP_CHECKSIG] * (MAX_BLOCK_SIGOPS_PER_MB - 1))
         block(
             19, spend=out[17], script=lots_of_checksigs, block_size=ONE_MEGABYTE)
         yield accepted()
 
         too_many_blk_checksigs = CScript(
             [OP_CHECKSIG] * MAX_BLOCK_SIGOPS_PER_MB)
         block(
             20, spend=out[18], script=too_many_blk_checksigs, block_size=ONE_MEGABYTE)
         yield rejected(RejectResult(16, b'bad-blk-sigops'))
 
         # Rewind bad block
         tip(19)
 
         # Accept 40k sigops per block > 1MB and <= 2MB
         block(21, spend=out[18], script=lots_of_checksigs,
               extra_sigops=MAX_BLOCK_SIGOPS_PER_MB, block_size=ONE_MEGABYTE + 1)
         yield accepted()
 
         # Accept 40k sigops per block > 1MB and <= 2MB
         block(22, spend=out[19], script=lots_of_checksigs,
               extra_sigops=MAX_BLOCK_SIGOPS_PER_MB, block_size=2 * ONE_MEGABYTE)
         yield accepted()
 
         # Reject more than 40k sigops per block > 1MB and <= 2MB.
         block(23, spend=out[20], script=lots_of_checksigs,
               extra_sigops=MAX_BLOCK_SIGOPS_PER_MB + 1, block_size=ONE_MEGABYTE + 1)
         yield rejected(RejectResult(16, b'bad-blk-sigops'))
 
         # Rewind bad block
         tip(22)
 
         # Reject more than 40k sigops per block > 1MB and <= 2MB.
         block(24, spend=out[20], script=lots_of_checksigs,
               extra_sigops=MAX_BLOCK_SIGOPS_PER_MB + 1, block_size=2 * ONE_MEGABYTE)
         yield rejected(RejectResult(16, b'bad-blk-sigops'))
 
         # Rewind bad block
         tip(22)
 
         # Accept 60k sigops per block > 2MB and <= 3MB
         block(25, spend=out[20], script=lots_of_checksigs, extra_sigops=2 *
               MAX_BLOCK_SIGOPS_PER_MB, block_size=2 * ONE_MEGABYTE + 1)
         yield accepted()
 
         # Accept 60k sigops per block > 2MB and <= 3MB
         block(26, spend=out[21], script=lots_of_checksigs,
               extra_sigops=2 * MAX_BLOCK_SIGOPS_PER_MB, block_size=3 * ONE_MEGABYTE)
         yield accepted()
 
         # Reject more than 40k sigops per block > 1MB and <= 2MB.
         block(27, spend=out[22], script=lots_of_checksigs, extra_sigops=2 *
               MAX_BLOCK_SIGOPS_PER_MB + 1, block_size=2 * ONE_MEGABYTE + 1)
         yield rejected(RejectResult(16, b'bad-blk-sigops'))
 
         # Rewind bad block
         tip(26)
 
         # Reject more than 40k sigops per block > 1MB and <= 2MB.
         block(28, spend=out[22], script=lots_of_checksigs, extra_sigops=2 *
               MAX_BLOCK_SIGOPS_PER_MB + 1, block_size=3 * ONE_MEGABYTE)
         yield rejected(RejectResult(16, b'bad-blk-sigops'))
 
         # Rewind bad block
         tip(26)
 
         # Too many sigops in one txn
         too_many_tx_checksigs = CScript(
             [OP_CHECKSIG] * (MAX_BLOCK_SIGOPS_PER_MB + 1))
         block(
             29, spend=out[22], script=too_many_tx_checksigs, block_size=ONE_MEGABYTE + 1)
         yield rejected(RejectResult(16, b'bad-txn-sigops'))
 
         # Rewind bad block
         tip(26)
 
         # P2SH
         # Build the redeem script, hash it, use hash to create the p2sh script
         redeem_script = CScript([self.coinbase_pubkey] + [
                                 OP_2DUP, OP_CHECKSIGVERIFY] * 5 + [OP_CHECKSIG])
         redeem_script_hash = hash160(redeem_script)
         p2sh_script = CScript([OP_HASH160, redeem_script_hash, OP_EQUAL])
 
         # Create a p2sh transaction
         p2sh_tx = self.create_and_sign_transaction(
             out[22].tx, out[22].n, 1, p2sh_script)
 
         # Add the transaction to the block
         block(30)
         update_block(30, [p2sh_tx])
         yield accepted()
 
         # Creates a new transaction using the p2sh transaction included in the
         # last block
         def spend_p2sh_tx(output_script=CScript([OP_TRUE])):
             # Create the transaction
             spent_p2sh_tx = CTransaction()
             spent_p2sh_tx.vin.append(CTxIn(COutPoint(p2sh_tx.sha256, 0), b''))
             spent_p2sh_tx.vout.append(CTxOut(1, output_script))
             # Sign the transaction using the redeem script
             sighash = SignatureHashForkId(
                 redeem_script, spent_p2sh_tx, 0, SIGHASH_ALL | SIGHASH_FORKID, p2sh_tx.vout[0].nValue)
             sig = self.coinbase_key.sign(sighash) + bytes(
                 bytearray([SIGHASH_ALL | SIGHASH_FORKID]))
             spent_p2sh_tx.vin[0].scriptSig = CScript([sig, redeem_script])
             spent_p2sh_tx.rehash()
             return spent_p2sh_tx
 
         # Sigops p2sh limit
         p2sh_sigops_limit = MAX_BLOCK_SIGOPS_PER_MB - \
             redeem_script.GetSigOpCount(True)
         # Too many sigops in one p2sh txn
         too_many_p2sh_sigops = CScript([OP_CHECKSIG] * (p2sh_sigops_limit + 1))
         block(31, spend=out[23], block_size=ONE_MEGABYTE + 1)
         update_block(31, [spend_p2sh_tx(too_many_p2sh_sigops)])
         yield rejected(RejectResult(16, b'bad-txn-sigops'))
 
         # Rewind bad block
         tip(30)
 
         # Max sigops in one p2sh txn
         max_p2sh_sigops = CScript([OP_CHECKSIG] * (p2sh_sigops_limit))
         block(32, spend=out[23], block_size=ONE_MEGABYTE + 1)
         update_block(32, [spend_p2sh_tx(max_p2sh_sigops)])
         yield accepted()
 
         # Check that compact block also work for big blocks
         node = self.nodes[0]
         peer = TestNode()
         peer.add_connection(NodeConn('127.0.0.1', p2p_port(0), node, peer))
 
         # Start up network handling in another thread and wait for connection
         # to be etablished
         NetworkThread().start()
         peer.wait_for_verack()
 
         # Wait for SENDCMPCT
         def received_sendcmpct():
             return (peer.last_sendcmpct != None)
         wait_until(received_sendcmpct, timeout=30)
 
         sendcmpct = msg_sendcmpct()
         sendcmpct.version = 1
         sendcmpct.announce = True
         peer.send_and_ping(sendcmpct)
 
         # Exchange headers
         def received_getheaders():
             return (peer.last_getheaders != None)
         wait_until(received_getheaders, timeout=30)
 
         # Return the favor
         peer.send_message(peer.last_getheaders)
 
         # Wait for the header list
         def received_headers():
             return (peer.last_headers != None)
         wait_until(received_headers, timeout=30)
 
         # It's like we know about the same headers !
         peer.send_message(peer.last_headers)
 
         # Send a block
         b33 = block(33, spend=out[24], block_size=ONE_MEGABYTE + 1)
         yield accepted()
 
         # Checks the node to forward it via compact block
         def received_block():
             return (peer.last_cmpctblock != None)
         wait_until(received_block, timeout=30)
 
         # Was it our block ?
         cmpctblk_header = peer.last_cmpctblock.header_and_shortids.header
         cmpctblk_header.calc_sha256()
         assert(cmpctblk_header.sha256 == b33.sha256)
 
         # Send a bigger block
         peer.clear_block_data()
         b34 = block(34, spend=out[25], block_size=8 * ONE_MEGABYTE)
         yield accepted()
 
         # Checks the node forwards it via compact block
         wait_until(received_block, timeout=30)
 
         # Was it our block ?
         cmpctblk_header = peer.last_cmpctblock.header_and_shortids.header
         cmpctblk_header.calc_sha256()
         assert(cmpctblk_header.sha256 == b34.sha256)
 
         # Let's send a compact block and see if the node accepts it.
         # First, we generate the block and send all transaction to the mempool
         b35 = block(35, spend=out[26], block_size=8 * ONE_MEGABYTE)
         for i in range(1, len(b35.vtx)):
             node.sendrawtransaction(ToHex(b35.vtx[i]), True)
 
         # Now we create the compact block and send it
         comp_block = HeaderAndShortIDs()
         comp_block.initialize_from_block(b35)
         peer.send_and_ping(msg_cmpctblock(comp_block.to_p2p()))
 
         # Check that compact block is received properly
         assert(int(node.getbestblockhash(), 16) == b35.sha256)
 
 
 if __name__ == '__main__':
     FullBlockTest().main()