diff --git a/src/validation.cpp b/src/validation.cpp
index 9a6006508..0f80330ea 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -1,6638 +1,6655 @@
// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2018 The Bitcoin Core developers
// Copyright (c) 2017-2020 The Bitcoin developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
#include <validation.h>
#include <kernel/chainparams.h>
#include <kernel/coinstats.h>
#include <kernel/disconnected_transactions.h>
#include <kernel/mempool_entry.h>
#include <kernel/mempool_persist.h>
#include <arith_uint256.h>
#include <avalanche/avalanche.h>
#include <avalanche/processor.h>
#include <blockvalidity.h>
#include <chainparams.h>
#include <checkpoints.h>
#include <checkqueue.h>
#include <common/args.h>
#include <config.h>
#include <consensus/activation.h>
#include <consensus/amount.h>
#include <consensus/merkle.h>
#include <consensus/tx_check.h>
#include <consensus/tx_verify.h>
#include <consensus/validation.h>
#include <hash.h>
#include <kernel/notifications_interface.h>
#include <logging.h>
#include <logging/timer.h>
#include <minerfund.h>
#include <node/blockstorage.h>
#include <node/utxo_snapshot.h>
#include <policy/block/minerfund.h>
#include <policy/block/preconsensus.h>
#include <policy/block/stakingrewards.h>
#include <policy/policy.h>
#include <policy/settings.h>
#include <pow/pow.h>
#include <primitives/block.h>
#include <primitives/transaction.h>
#include <random.h>
#include <reverse_iterator.h>
#include <script/script.h>
#include <script/scriptcache.h>
#include <script/sigcache.h>
#include <shutdown.h>
#include <tinyformat.h>
#include <txdb.h>
#include <txmempool.h>
#include <undo.h>
#include <util/check.h> // For NDEBUG compile time check
#include <util/fs.h>
#include <util/fs_helpers.h>
#include <util/strencodings.h>
#include <util/string.h>
#include <util/time.h>
#include <util/trace.h>
#include <util/translation.h>
#include <validationinterface.h>
#include <warnings.h>
#include <algorithm>
#include <atomic>
#include <cassert>
#include <chrono>
#include <deque>
#include <numeric>
#include <optional>
#include <string>
#include <thread>
using kernel::CCoinsStats;
using kernel::CoinStatsHashType;
using kernel::ComputeUTXOStats;
using kernel::LoadMempool;
using kernel::Notifications;
using fsbridge::FopenFn;
using node::BLOCKFILE_CHUNK_SIZE;
using node::BlockManager;
using node::BlockMap;
using node::fReindex;
using node::SnapshotMetadata;
using node::UNDOFILE_CHUNK_SIZE;
#define MICRO 0.000001
#define MILLI 0.001
/** Time to wait between writing blocks/block index to disk. */
static constexpr std::chrono::hours DATABASE_WRITE_INTERVAL{1};
/** Time to wait between flushing chainstate to disk. */
static constexpr std::chrono::hours DATABASE_FLUSH_INTERVAL{24};
const std::vector<std::string> CHECKLEVEL_DOC{
"level 0 reads the blocks from disk",
"level 1 verifies block validity",
"level 2 verifies undo data",
"level 3 checks disconnection of tip blocks",
"level 4 tries to reconnect the blocks",
"each level includes the checks of the previous levels",
};
/**
* The number of blocks to keep below the deepest prune lock.
* There is nothing special about this number. It is higher than what we
* expect to see in regular mainnet reorgs, but not so high that it would
* noticeably interfere with the pruning mechanism.
* */
static constexpr int PRUNE_LOCK_BUFFER{10};
GlobalMutex g_best_block_mutex;
std::condition_variable g_best_block_cv;
uint256 g_best_block;
BlockValidationOptions::BlockValidationOptions(const Config &config)
: excessiveBlockSize(config.GetMaxBlockSize()), checkPoW(true),
checkMerkleRoot(true) {}
const CBlockIndex *
Chainstate::FindForkInGlobalIndex(const CBlockLocator &locator) const {
AssertLockHeld(cs_main);
// Find the latest block common to locator and chain - we expect that
// locator.vHave is sorted descending by height.
for (const BlockHash &hash : locator.vHave) {
const CBlockIndex *pindex{m_blockman.LookupBlockIndex(hash)};
if (pindex) {
if (m_chain.Contains(pindex)) {
return pindex;
}
if (pindex->GetAncestor(m_chain.Height()) == m_chain.Tip()) {
return m_chain.Tip();
}
}
}
return m_chain.Genesis();
}
static uint32_t GetNextBlockScriptFlags(const CBlockIndex *pindex,
const ChainstateManager &chainman);
namespace {
/**
* A helper which calculates heights of inputs of a given transaction.
*
* @param[in] tip The current chain tip. If an input belongs to a mempool
* transaction, we assume it will be confirmed in the next
* block.
* @param[in] coins Any CCoinsView that provides access to the relevant coins.
* @param[in] tx The transaction being evaluated.
*
* @returns A vector of input heights or nullopt, in case of an error.
*/
std::optional<std::vector<int>> CalculatePrevHeights(const CBlockIndex &tip,
const CCoinsView &coins,
const CTransaction &tx) {
std::vector<int> prev_heights;
prev_heights.resize(tx.vin.size());
for (size_t i = 0; i < tx.vin.size(); ++i) {
const CTxIn &txin = tx.vin[i];
Coin coin;
if (!coins.GetCoin(txin.prevout, coin)) {
LogPrintf("ERROR: %s: Missing input %d in transaction \'%s\'\n",
__func__, i, tx.GetId().GetHex());
return std::nullopt;
}
if (coin.GetHeight() == MEMPOOL_HEIGHT) {
// Assume all mempool transaction confirm in the next block.
prev_heights[i] = tip.nHeight + 1;
} else {
prev_heights[i] = coin.GetHeight();
}
}
return prev_heights;
}
} // namespace
std::optional<LockPoints> CalculateLockPointsAtTip(CBlockIndex *tip,
const CCoinsView &coins_view,
const CTransaction &tx) {
assert(tip);
auto prev_heights{CalculatePrevHeights(*tip, coins_view, tx)};
if (!prev_heights.has_value()) {
return std::nullopt;
}
CBlockIndex next_tip;
next_tip.pprev = tip;
// When SequenceLocks() is called within ConnectBlock(), the height
// of the block *being* evaluated is what is used.
// Thus if we want to know if a transaction can be part of the
// *next* block, we need to use one more than
// active_chainstate.m_chain.Height()
next_tip.nHeight = tip->nHeight + 1;
const auto [min_height, min_time] = CalculateSequenceLocks(
tx, STANDARD_LOCKTIME_VERIFY_FLAGS, prev_heights.value(), next_tip);
return LockPoints{min_height, min_time};
}
bool CheckSequenceLocksAtTip(CBlockIndex *tip, const LockPoints &lock_points) {
assert(tip != nullptr);
CBlockIndex index;
index.pprev = tip;
// CheckSequenceLocksAtTip() uses active_chainstate.m_chain.Height()+1 to
// evaluate height based locks because when SequenceLocks() is called within
// ConnectBlock(), the height of the block *being* evaluated is what is
// used. Thus if we want to know if a transaction can be part of the *next*
// block, we need to use one more than active_chainstate.m_chain.Height()
index.nHeight = tip->nHeight + 1;
return EvaluateSequenceLocks(index, {lock_points.height, lock_points.time});
}
// Command-line argument "-replayprotectionactivationtime=<timestamp>" will
// cause the node to switch to replay protected SigHash ForkID value when the
// median timestamp of the previous 11 blocks is greater than or equal to
// <timestamp>. Defaults to the pre-defined timestamp when not set.
static bool IsReplayProtectionEnabled(const Consensus::Params ¶ms,
int64_t nMedianTimePast) {
return nMedianTimePast >= gArgs.GetIntArg("-replayprotectionactivationtime",
params.augustoActivationTime);
}
static bool IsReplayProtectionEnabled(const Consensus::Params ¶ms,
const CBlockIndex *pindexPrev) {
if (pindexPrev == nullptr) {
return false;
}
return IsReplayProtectionEnabled(params, pindexPrev->GetMedianTimePast());
}
/**
* Checks to avoid mempool polluting consensus critical paths since cached
* signature and script validity results will be reused if we validate this
* transaction again during block validation.
*/
static bool CheckInputsFromMempoolAndCache(
const CTransaction &tx, TxValidationState &state,
const CCoinsViewCache &view, const CTxMemPool &pool, const uint32_t flags,
PrecomputedTransactionData &txdata, int &nSigChecksOut,
CCoinsViewCache &coins_tip) EXCLUSIVE_LOCKS_REQUIRED(cs_main, pool.cs) {
AssertLockHeld(cs_main);
AssertLockHeld(pool.cs);
assert(!tx.IsCoinBase());
for (const CTxIn &txin : tx.vin) {
const Coin &coin = view.AccessCoin(txin.prevout);
// This coin was checked in PreChecks and MemPoolAccept
// has been holding cs_main since then.
Assume(!coin.IsSpent());
if (coin.IsSpent()) {
return false;
}
// If the Coin is available, there are 2 possibilities:
// it is available in our current ChainstateActive UTXO set,
// or it's a UTXO provided by a transaction in our mempool.
// Ensure the scriptPubKeys in Coins from CoinsView are correct.
const CTransactionRef &txFrom = pool.get(txin.prevout.GetTxId());
if (txFrom) {
assert(txFrom->GetId() == txin.prevout.GetTxId());
assert(txFrom->vout.size() > txin.prevout.GetN());
assert(txFrom->vout[txin.prevout.GetN()] == coin.GetTxOut());
} else {
const Coin &coinFromUTXOSet = coins_tip.AccessCoin(txin.prevout);
assert(!coinFromUTXOSet.IsSpent());
assert(coinFromUTXOSet.GetTxOut() == coin.GetTxOut());
}
}
// Call CheckInputScripts() to cache signature and script validity against
// current tip consensus rules.
return CheckInputScripts(tx, state, view, flags, /*sigCacheStore=*/true,
/*scriptCacheStore=*/true, txdata, nSigChecksOut);
}
namespace {
class MemPoolAccept {
public:
MemPoolAccept(CTxMemPool &mempool, Chainstate &active_chainstate)
: m_pool(mempool), m_view(&m_dummy),
m_viewmempool(&active_chainstate.CoinsTip(), m_pool),
m_active_chainstate(active_chainstate) {}
// We put the arguments we're handed into a struct, so we can pass them
// around easier.
struct ATMPArgs {
const Config &m_config;
const int64_t m_accept_time;
const bool m_bypass_limits;
/*
* Return any outpoints which were not previously present in the coins
* cache, but were added as a result of validating the tx for mempool
* acceptance. This allows the caller to optionally remove the cache
* additions if the associated transaction ends up being rejected by
* the mempool.
*/
std::vector<COutPoint> &m_coins_to_uncache;
const bool m_test_accept;
const unsigned int m_heightOverride;
/**
* When true, the mempool will not be trimmed when individual
* transactions are submitted in Finalize(). Instead, limits should be
* enforced at the end to ensure the package is not partially submitted.
*/
const bool m_package_submission;
/** Parameters for single transaction mempool validation. */
static ATMPArgs SingleAccept(const Config &config, int64_t accept_time,
bool bypass_limits,
std::vector<COutPoint> &coins_to_uncache,
bool test_accept,
unsigned int heightOverride) {
return ATMPArgs{config,
accept_time,
bypass_limits,
coins_to_uncache,
test_accept,
heightOverride,
/*package_submission=*/false};
}
/**
* Parameters for test package mempool validation through
* testmempoolaccept.
*/
static ATMPArgs
PackageTestAccept(const Config &config, int64_t accept_time,
std::vector<COutPoint> &coins_to_uncache) {
return ATMPArgs{config, accept_time,
/*bypass_limits=*/false, coins_to_uncache,
/*test_accept=*/true,
/*height_override=*/0,
// not submitting to mempool
/*package_submission=*/false};
}
/** Parameters for child-with-unconfirmed-parents package validation. */
static ATMPArgs
PackageChildWithParents(const Config &config, int64_t accept_time,
std::vector<COutPoint> &coins_to_uncache) {
return ATMPArgs{config,
accept_time,
/*bypass_limits=*/false,
coins_to_uncache,
/*test_accept=*/false,
/*height_override=*/0,
/*package_submission=*/true};
}
private:
// Private ctor to avoid exposing details to clients and allowing the
// possibility of mixing up the order of the arguments. Use static
// functions above instead.
ATMPArgs(const Config &config, int64_t accept_time, bool bypass_limits,
std::vector<COutPoint> &coins_to_uncache, bool test_accept,
unsigned int height_override, bool package_submission)
: m_config{config}, m_accept_time{accept_time},
m_bypass_limits{bypass_limits},
m_coins_to_uncache{coins_to_uncache}, m_test_accept{test_accept},
m_heightOverride{height_override}, m_package_submission{
package_submission} {}
};
// Single transaction acceptance
MempoolAcceptResult AcceptSingleTransaction(const CTransactionRef &ptx,
ATMPArgs &args)
EXCLUSIVE_LOCKS_REQUIRED(cs_main);
/**
* Multiple transaction acceptance. Transactions may or may not be
* interdependent, but must not conflict with each other, and the
* transactions cannot already be in the mempool. Parents must come
* before children if any dependencies exist.
*/
PackageMempoolAcceptResult
AcceptMultipleTransactions(const std::vector<CTransactionRef> &txns,
ATMPArgs &args)
EXCLUSIVE_LOCKS_REQUIRED(cs_main);
/**
* Package (more specific than just multiple transactions) acceptance.
* Package must be a child with all of its unconfirmed parents, and
* topologically sorted.
*/
PackageMempoolAcceptResult AcceptPackage(const Package &package,
ATMPArgs &args)
EXCLUSIVE_LOCKS_REQUIRED(cs_main);
private:
// All the intermediate state that gets passed between the various levels
// of checking a given transaction.
struct Workspace {
Workspace(const CTransactionRef &ptx,
const uint32_t next_block_script_verify_flags)
: m_ptx(ptx),
m_next_block_script_verify_flags(next_block_script_verify_flags) {
}
/**
* Mempool entry constructed for this transaction.
* Constructed in PreChecks() but not inserted into the mempool until
* Finalize().
*/
std::unique_ptr<CTxMemPoolEntry> m_entry;
/**
* Virtual size of the transaction as used by the mempool, calculated
* using serialized size of the transaction and sigchecks.
*/
int64_t m_vsize;
/**
* Fees paid by this transaction: total input amounts subtracted by
* total output amounts.
*/
Amount m_base_fees;
/**
* Base fees + any fee delta set by the user with
* prioritisetransaction.
*/
Amount m_modified_fees;
const CTransactionRef &m_ptx;
TxValidationState m_state;
/**
* A temporary cache containing serialized transaction data for
* signature verification.
* Reused across PreChecks and ConsensusScriptChecks.
*/
PrecomputedTransactionData m_precomputed_txdata;
// ABC specific flags that are used in both PreChecks and
// ConsensusScriptChecks
const uint32_t m_next_block_script_verify_flags;
int m_sig_checks_standard;
};
// Run the policy checks on a given transaction, excluding any script
// checks. Looks up inputs, calculates feerate, considers replacement,
// evaluates package limits, etc. As this function can be invoked for "free"
// by a peer, only tests that are fast should be done here (to avoid CPU
// DoS).
bool PreChecks(ATMPArgs &args, Workspace &ws)
EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs);
// Re-run the script checks, using consensus flags, and try to cache the
// result in the scriptcache. This should be done after
// PolicyScriptChecks(). This requires that all inputs either be in our
// utxo set or in the mempool.
bool ConsensusScriptChecks(const ATMPArgs &args, Workspace &ws)
EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs);
// Try to add the transaction to the mempool, removing any conflicts first.
// Returns true if the transaction is in the mempool after any size
// limiting is performed, false otherwise.
bool Finalize(const ATMPArgs &args, Workspace &ws)
EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs);
// Submit all transactions to the mempool and call ConsensusScriptChecks to
// add to the script cache - should only be called after successful
// validation of all transactions in the package.
// The package may end up partially-submitted after size limiting;
// returns true if all transactions are successfully added to the mempool,
// false otherwise.
bool SubmitPackage(const ATMPArgs &args, std::vector<Workspace> &workspaces,
PackageValidationState &package_state,
std::map<const TxId, const MempoolAcceptResult> &results)
EXCLUSIVE_LOCKS_REQUIRED(cs_main, m_pool.cs);
+ // Compare a package's feerate against minimum allowed.
+ bool CheckFeeRate(size_t package_size, size_t package_vsize,
+ Amount package_fee, TxValidationState &state)
+ EXCLUSIVE_LOCKS_REQUIRED(::cs_main, m_pool.cs) {
+ AssertLockHeld(::cs_main);
+ AssertLockHeld(m_pool.cs);
+
+ const Amount mempoolRejectFee =
+ m_pool.GetMinFee().GetFee(package_vsize);
+
+ if (mempoolRejectFee > Amount::zero() &&
+ package_fee < mempoolRejectFee) {
+ return state.Invalid(
+ TxValidationResult::TX_MEMPOOL_POLICY,
+ "mempool min fee not met",
+ strprintf("%d < %d", package_fee, mempoolRejectFee));
+ }
+
+ // No transactions are allowed below the min relay feerate except from
+ // disconnected blocks.
+ // Do not change this to use virtualsize without coordinating a network
+ // policy upgrade.
+ if (package_fee < m_pool.m_min_relay_feerate.GetFee(package_size)) {
+ return state.Invalid(
+ TxValidationResult::TX_MEMPOOL_POLICY, "min relay fee not met",
+ strprintf("%d < %d", package_fee,
+ m_pool.m_min_relay_feerate.GetFee(package_size)));
+ }
+
+ return true;
+ }
+
private:
CTxMemPool &m_pool;
CCoinsViewCache m_view;
CCoinsViewMemPool m_viewmempool;
CCoinsView m_dummy;
Chainstate &m_active_chainstate;
};
bool MemPoolAccept::PreChecks(ATMPArgs &args, Workspace &ws) {
AssertLockHeld(cs_main);
AssertLockHeld(m_pool.cs);
const CTransactionRef &ptx = ws.m_ptx;
const CTransaction &tx = *ws.m_ptx;
const TxId &txid = ws.m_ptx->GetId();
// Copy/alias what we need out of args
const int64_t nAcceptTime = args.m_accept_time;
const bool bypass_limits = args.m_bypass_limits;
std::vector<COutPoint> &coins_to_uncache = args.m_coins_to_uncache;
const unsigned int heightOverride = args.m_heightOverride;
// Alias what we need out of ws
TxValidationState &state = ws.m_state;
// Coinbase is only valid in a block, not as a loose transaction.
if (!CheckRegularTransaction(tx, state)) {
// state filled in by CheckRegularTransaction.
return false;
}
// Rather not work on nonstandard transactions (unless -testnet)
std::string reason;
if (m_pool.m_require_standard &&
!IsStandardTx(tx, m_pool.m_max_datacarrier_bytes,
m_pool.m_permit_bare_multisig,
m_pool.m_dust_relay_feerate, reason)) {
return state.Invalid(TxValidationResult::TX_NOT_STANDARD, reason);
}
// Only accept nLockTime-using transactions that can be mined in the next
// block; we don't want our mempool filled up with transactions that can't
// be mined yet.
TxValidationState ctxState;
if (!ContextualCheckTransactionForCurrentBlock(
*Assert(m_active_chainstate.m_chain.Tip()),
args.m_config.GetChainParams().GetConsensus(), tx, ctxState)) {
// We copy the state from a dummy to ensure we don't increase the
// ban score of peer for transaction that could be valid in the future.
return state.Invalid(TxValidationResult::TX_PREMATURE_SPEND,
ctxState.GetRejectReason(),
ctxState.GetDebugMessage());
}
// Is it already in the memory pool?
if (m_pool.exists(txid)) {
return state.Invalid(TxValidationResult::TX_DUPLICATE,
"txn-already-in-mempool");
}
// Check for conflicts with in-memory transactions
for (const CTxIn &txin : tx.vin) {
const CTransaction *ptxConflicting = m_pool.GetConflictTx(txin.prevout);
if (ptxConflicting) {
// Disable replacement feature for good
return state.Invalid(TxValidationResult::TX_CONFLICT,
"txn-mempool-conflict");
}
}
m_view.SetBackend(m_viewmempool);
const CCoinsViewCache &coins_cache = m_active_chainstate.CoinsTip();
// Do all inputs exist?
for (const CTxIn &txin : tx.vin) {
if (!coins_cache.HaveCoinInCache(txin.prevout)) {
coins_to_uncache.push_back(txin.prevout);
}
// Note: this call may add txin.prevout to the coins cache
// (coins_cache.cacheCoins) by way of FetchCoin(). It should be
// removed later (via coins_to_uncache) if this tx turns out to be
// invalid.
if (!m_view.HaveCoin(txin.prevout)) {
// Are inputs missing because we already have the tx?
for (size_t out = 0; out < tx.vout.size(); out++) {
// Optimistically just do efficient check of cache for
// outputs.
if (coins_cache.HaveCoinInCache(COutPoint(txid, out))) {
return state.Invalid(TxValidationResult::TX_DUPLICATE,
"txn-already-known");
}
}
// Otherwise assume this might be an orphan tx for which we just
// haven't seen parents yet.
return state.Invalid(TxValidationResult::TX_MISSING_INPUTS,
"bad-txns-inputs-missingorspent");
}
}
// Are the actual inputs available?
if (!m_view.HaveInputs(tx)) {
return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY,
"bad-txns-inputs-spent");
}
// Bring the best block into scope.
m_view.GetBestBlock();
// we have all inputs cached now, so switch back to dummy (to protect
// against bugs where we pull more inputs from disk that miss being
// added to coins_to_uncache)
m_view.SetBackend(m_dummy);
assert(m_active_chainstate.m_blockman.LookupBlockIndex(
m_view.GetBestBlock()) == m_active_chainstate.m_chain.Tip());
// Only accept BIP68 sequence locked transactions that can be mined in
// the next block; we don't want our mempool filled up with transactions
// that can't be mined yet.
// Pass in m_view which has all of the relevant inputs cached. Note that,
// since m_view's backend was removed, it no longer pulls coins from the
// mempool.
const std::optional<LockPoints> lock_points{CalculateLockPointsAtTip(
m_active_chainstate.m_chain.Tip(), m_view, tx)};
if (!lock_points.has_value() ||
!CheckSequenceLocksAtTip(m_active_chainstate.m_chain.Tip(),
*lock_points)) {
return state.Invalid(TxValidationResult::TX_PREMATURE_SPEND,
"non-BIP68-final");
}
// The mempool holds txs for the next block, so pass height+1 to
// CheckTxInputs
if (!Consensus::CheckTxInputs(tx, state, m_view,
m_active_chainstate.m_chain.Height() + 1,
ws.m_base_fees)) {
// state filled in by CheckTxInputs
return false;
}
// Check for non-standard pay-to-script-hash in inputs
if (m_pool.m_require_standard &&
!AreInputsStandard(tx, m_view, ws.m_next_block_script_verify_flags)) {
return state.Invalid(TxValidationResult::TX_INPUTS_NOT_STANDARD,
"bad-txns-nonstandard-inputs");
}
// ws.m_modified_fess includes any fee deltas from PrioritiseTransaction
ws.m_modified_fees = ws.m_base_fees;
m_pool.ApplyDelta(txid, ws.m_modified_fees);
unsigned int nSize = tx.GetTotalSize();
- // No transactions are allowed below the min relay feerate except from
- // disconnected blocks.
- // Do not change this to use virtualsize without coordinating a network
- // policy upgrade.
- if (!bypass_limits &&
- ws.m_modified_fees < m_pool.m_min_relay_feerate.GetFee(nSize)) {
- return state.Invalid(
- TxValidationResult::TX_MEMPOOL_POLICY, "min relay fee not met",
- strprintf("%d < %d", ws.m_modified_fees,
- m_pool.m_min_relay_feerate.GetFee(nSize)));
- }
-
// Validate input scripts against standard script flags.
const uint32_t scriptVerifyFlags =
ws.m_next_block_script_verify_flags | STANDARD_SCRIPT_VERIFY_FLAGS;
ws.m_precomputed_txdata = PrecomputedTransactionData{tx};
if (!CheckInputScripts(tx, state, m_view, scriptVerifyFlags, true, false,
ws.m_precomputed_txdata, ws.m_sig_checks_standard)) {
// State filled in by CheckInputScripts
return false;
}
ws.m_entry = std::make_unique<CTxMemPoolEntry>(
ptx, ws.m_base_fees, nAcceptTime,
heightOverride ? heightOverride : m_active_chainstate.m_chain.Height(),
ws.m_sig_checks_standard, lock_points.value());
ws.m_vsize = ws.m_entry->GetTxVirtualSize();
- Amount mempoolRejectFee = m_pool.GetMinFee().GetFee(ws.m_vsize);
- if (!bypass_limits && mempoolRejectFee > Amount::zero() &&
- ws.m_modified_fees < mempoolRejectFee) {
- return state.Invalid(
- TxValidationResult::TX_MEMPOOL_POLICY, "mempool min fee not met",
- strprintf("%d < %d", ws.m_modified_fees, mempoolRejectFee));
+ if (!bypass_limits &&
+ !CheckFeeRate(nSize, ws.m_vsize, ws.m_modified_fees, state)) {
+ return false;
}
return true;
}
bool MemPoolAccept::ConsensusScriptChecks(const ATMPArgs &args, Workspace &ws) {
AssertLockHeld(cs_main);
AssertLockHeld(m_pool.cs);
const CTransaction &tx = *ws.m_ptx;
const TxId &txid = tx.GetId();
TxValidationState &state = ws.m_state;
// Check again against the next block's script verification flags
// to cache our script execution flags.
//
// This is also useful in case of bugs in the standard flags that cause
// transactions to pass as valid when they're actually invalid. For
// instance the STRICTENC flag was incorrectly allowing certain CHECKSIG
// NOT scripts to pass, even though they were invalid.
//
// There is a similar check in CreateNewBlock() to prevent creating
// invalid blocks (using TestBlockValidity), however allowing such
// transactions into the mempool can be exploited as a DoS attack.
int nSigChecksConsensus;
if (!CheckInputsFromMempoolAndCache(
tx, state, m_view, m_pool, ws.m_next_block_script_verify_flags,
ws.m_precomputed_txdata, nSigChecksConsensus,
m_active_chainstate.CoinsTip())) {
// This can occur under some circumstances, if the node receives an
// unrequested tx which is invalid due to new consensus rules not
// being activated yet (during IBD).
LogPrintf("BUG! PLEASE REPORT THIS! CheckInputScripts failed against "
"latest-block but not STANDARD flags %s, %s\n",
txid.ToString(), state.ToString());
return Assume(false);
}
if (ws.m_sig_checks_standard != nSigChecksConsensus) {
// We can't accept this transaction as we've used the standard count
// for the mempool/mining, but the consensus count will be enforced
// in validation (we don't want to produce bad block templates).
return error(
"%s: BUG! PLEASE REPORT THIS! SigChecks count differed between "
"standard and consensus flags in %s",
__func__, txid.ToString());
}
return true;
}
bool MemPoolAccept::Finalize(const ATMPArgs &args, Workspace &ws) {
AssertLockHeld(cs_main);
AssertLockHeld(m_pool.cs);
const TxId &txid = ws.m_ptx->GetId();
TxValidationState &state = ws.m_state;
const bool bypass_limits = args.m_bypass_limits;
// Store transaction in memory
CTxMemPoolEntry *pentry = ws.m_entry.release();
auto entry = CTxMemPoolEntryRef::acquire(pentry);
m_pool.addUnchecked(entry);
// Trim mempool and check if tx was trimmed.
// If we are validating a package, don't trim here because we could evict a
// previous transaction in the package. LimitMempoolSize() should be called
// at the very end to make sure the mempool is still within limits and
// package submission happens atomically.
if (!args.m_package_submission && !bypass_limits) {
m_pool.LimitSize(m_active_chainstate.CoinsTip());
if (!m_pool.exists(txid)) {
return state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY,
"mempool full");
}
}
return true;
}
// Get the coins spent by ptx from the coins_view. Assumes coins are present.
static std::vector<Coin> getSpentCoins(const CTransactionRef &ptx,
const CCoinsViewCache &coins_view) {
std::vector<Coin> spent_coins;
spent_coins.reserve(ptx->vin.size());
for (const CTxIn &input : ptx->vin) {
Coin coin;
const bool coinFound = coins_view.GetCoin(input.prevout, coin);
Assume(coinFound);
spent_coins.push_back(std::move(coin));
}
return spent_coins;
}
bool MemPoolAccept::SubmitPackage(
const ATMPArgs &args, std::vector<Workspace> &workspaces,
PackageValidationState &package_state,
std::map<const TxId, const MempoolAcceptResult> &results) {
AssertLockHeld(cs_main);
AssertLockHeld(m_pool.cs);
// Sanity check: none of the transactions should be in the mempool.
assert(std::all_of(
workspaces.cbegin(), workspaces.cend(),
[this](const auto &ws) { return !m_pool.exists(ws.m_ptx->GetId()); }));
bool all_submitted = true;
// ConsensusScriptChecks adds to the script cache and is therefore
// consensus-critical; CheckInputsFromMempoolAndCache asserts that
// transactions only spend coins available from the mempool or UTXO set.
// Submit each transaction to the mempool immediately after calling
// ConsensusScriptChecks to make the outputs available for subsequent
// transactions.
for (Workspace &ws : workspaces) {
if (!ConsensusScriptChecks(args, ws)) {
results.emplace(ws.m_ptx->GetId(),
MempoolAcceptResult::Failure(ws.m_state));
// Since PreChecks() passed, this should never fail.
all_submitted = Assume(false);
}
// If we call LimitMempoolSize() for each individual Finalize(), the
// mempool will not take the transaction's descendant feerate into
// account because it hasn't seen them yet. Also, we risk evicting a
// transaction that a subsequent package transaction depends on.
// Instead, allow the mempool to temporarily bypass limits, the maximum
// package size) while submitting transactions individually and then
// trim at the very end.
if (!Finalize(args, ws)) {
results.emplace(ws.m_ptx->GetId(),
MempoolAcceptResult::Failure(ws.m_state));
// Since LimitMempoolSize() won't be called, this should never fail.
all_submitted = Assume(false);
}
}
// It may or may not be the case that all the transactions made it into the
// mempool. Regardless, make sure we haven't exceeded max mempool size.
m_pool.LimitSize(m_active_chainstate.CoinsTip());
if (!all_submitted) {
return false;
}
// Find the txids of the transactions that made it into the mempool. Allow
// partial submission, but don't report success unless they all made it into
// the mempool.
for (Workspace &ws : workspaces) {
if (m_pool.exists(ws.m_ptx->GetId())) {
results.emplace(ws.m_ptx->GetId(), MempoolAcceptResult::Success(
ws.m_vsize, ws.m_base_fees));
GetMainSignals().TransactionAddedToMempool(
ws.m_ptx,
std::make_shared<const std::vector<Coin>>(
getSpentCoins(ws.m_ptx, m_view)),
m_pool.GetAndIncrementSequence());
} else {
all_submitted = false;
ws.m_state.Invalid(TxValidationResult::TX_MEMPOOL_POLICY,
"mempool full");
results.emplace(ws.m_ptx->GetId(),
MempoolAcceptResult::Failure(ws.m_state));
}
}
return all_submitted;
}
MempoolAcceptResult
MemPoolAccept::AcceptSingleTransaction(const CTransactionRef &ptx,
ATMPArgs &args) {
AssertLockHeld(cs_main);
// mempool "read lock" (held through
// GetMainSignals().TransactionAddedToMempool())
LOCK(m_pool.cs);
const CBlockIndex *tip = m_active_chainstate.m_chain.Tip();
Workspace ws(ptx,
GetNextBlockScriptFlags(tip, m_active_chainstate.m_chainman));
// Perform the inexpensive checks first and avoid hashing and signature
// verification unless those checks pass, to mitigate CPU exhaustion
// denial-of-service attacks.
if (!PreChecks(args, ws)) {
return MempoolAcceptResult::Failure(ws.m_state);
}
if (!ConsensusScriptChecks(args, ws)) {
return MempoolAcceptResult::Failure(ws.m_state);
}
const TxId txid = ptx->GetId();
// Mempool sanity check -- in our new mempool no tx can be added if its
// outputs are already spent in the mempool (that is, no children before
// parents allowed; the mempool must be consistent at all times).
//
// This means that on reorg, the disconnectpool *must* always import
// the existing mempool tx's, clear the mempool, and then re-add
// remaining tx's in topological order via this function. Our new mempool
// has fast adds, so this is ok.
if (auto it = m_pool.mapNextTx.lower_bound(COutPoint{txid, 0});
it != m_pool.mapNextTx.end() && it->first->GetTxId() == txid) {
LogPrintf("%s: BUG! PLEASE REPORT THIS! Attempt to add txid %s, but "
"its outputs are already spent in the "
"mempool\n",
__func__, txid.ToString());
ws.m_state.Invalid(TxValidationResult::TX_CHILD_BEFORE_PARENT,
"txn-child-before-parent");
return MempoolAcceptResult::Failure(ws.m_state);
}
// Tx was accepted, but not added
if (args.m_test_accept) {
return MempoolAcceptResult::Success(ws.m_vsize, ws.m_base_fees);
}
if (!Finalize(args, ws)) {
return MempoolAcceptResult::Failure(ws.m_state);
}
GetMainSignals().TransactionAddedToMempool(
ptx,
std::make_shared<const std::vector<Coin>>(getSpentCoins(ptx, m_view)),
m_pool.GetAndIncrementSequence());
return MempoolAcceptResult::Success(ws.m_vsize, ws.m_base_fees);
}
PackageMempoolAcceptResult MemPoolAccept::AcceptMultipleTransactions(
const std::vector<CTransactionRef> &txns, ATMPArgs &args) {
AssertLockHeld(cs_main);
// These context-free package limits can be done before taking the mempool
// lock.
PackageValidationState package_state;
if (!CheckPackage(txns, package_state)) {
return PackageMempoolAcceptResult(package_state, {});
}
std::vector<Workspace> workspaces{};
workspaces.reserve(txns.size());
std::transform(
txns.cbegin(), txns.cend(), std::back_inserter(workspaces),
[this](const auto &tx) {
return Workspace(
tx, GetNextBlockScriptFlags(m_active_chainstate.m_chain.Tip(),
m_active_chainstate.m_chainman));
});
std::map<const TxId, const MempoolAcceptResult> results;
LOCK(m_pool.cs);
// Do all PreChecks first and fail fast to avoid running expensive script
// checks when unnecessary.
for (Workspace &ws : workspaces) {
if (!PreChecks(args, ws)) {
package_state.Invalid(PackageValidationResult::PCKG_TX,
"transaction failed");
// Exit early to avoid doing pointless work. Update the failed tx
// result; the rest are unfinished.
results.emplace(ws.m_ptx->GetId(),
MempoolAcceptResult::Failure(ws.m_state));
return PackageMempoolAcceptResult(package_state,
std::move(results));
}
// Make the coins created by this transaction available for subsequent
// transactions in the package to spend.
m_viewmempool.PackageAddTransaction(ws.m_ptx);
if (args.m_test_accept) {
// When test_accept=true, transactions that pass PreChecks
// are valid because there are no further mempool checks (passing
// PreChecks implies passing ConsensusScriptChecks).
results.emplace(ws.m_ptx->GetId(), MempoolAcceptResult::Success(
ws.m_vsize, ws.m_base_fees));
}
}
if (args.m_test_accept) {
return PackageMempoolAcceptResult(package_state, std::move(results));
}
if (!SubmitPackage(args, workspaces, package_state, results)) {
package_state.Invalid(PackageValidationResult::PCKG_TX,
"submission failed");
return PackageMempoolAcceptResult(package_state, std::move(results));
}
return PackageMempoolAcceptResult(package_state, std::move(results));
}
PackageMempoolAcceptResult MemPoolAccept::AcceptPackage(const Package &package,
ATMPArgs &args) {
AssertLockHeld(cs_main);
PackageValidationState package_state;
// Check that the package is well-formed. If it isn't, we won't try to
// validate any of the transactions and thus won't return any
// MempoolAcceptResults, just a package-wide error.
// Context-free package checks.
if (!CheckPackage(package, package_state)) {
return PackageMempoolAcceptResult(package_state, {});
}
// All transactions in the package must be a parent of the last transaction.
// This is just an opportunity for us to fail fast on a context-free check
// without taking the mempool lock.
if (!IsChildWithParents(package)) {
package_state.Invalid(PackageValidationResult::PCKG_POLICY,
"package-not-child-with-parents");
return PackageMempoolAcceptResult(package_state, {});
}
// IsChildWithParents() guarantees the package is > 1 transactions.
assert(package.size() > 1);
// The package must be 1 child with all of its unconfirmed parents. The
// package is expected to be sorted, so the last transaction is the child.
const auto &child = package.back();
std::unordered_set<TxId, SaltedTxIdHasher> unconfirmed_parent_txids;
std::transform(
package.cbegin(), package.cend() - 1,
std::inserter(unconfirmed_parent_txids, unconfirmed_parent_txids.end()),
[](const auto &tx) { return tx->GetId(); });
// All child inputs must refer to a preceding package transaction or a
// confirmed UTXO. The only way to verify this is to look up the child's
// inputs in our current coins view (not including mempool), and enforce
// that all parents not present in the package be available at chain tip.
// Since this check can bring new coins into the coins cache, keep track of
// these coins and uncache them if we don't end up submitting this package
// to the mempool.
const CCoinsViewCache &coins_tip_cache = m_active_chainstate.CoinsTip();
for (const auto &input : child->vin) {
if (!coins_tip_cache.HaveCoinInCache(input.prevout)) {
args.m_coins_to_uncache.push_back(input.prevout);
}
}
// Using the MemPoolAccept m_view cache allows us to look up these same
// coins faster later. This should be connecting directly to CoinsTip, not
// to m_viewmempool, because we specifically require inputs to be confirmed
// if they aren't in the package.
m_view.SetBackend(m_active_chainstate.CoinsTip());
const auto package_or_confirmed = [this, &unconfirmed_parent_txids](
const auto &input) {
return unconfirmed_parent_txids.count(input.prevout.GetTxId()) > 0 ||
m_view.HaveCoin(input.prevout);
};
if (!std::all_of(child->vin.cbegin(), child->vin.cend(),
package_or_confirmed)) {
package_state.Invalid(PackageValidationResult::PCKG_POLICY,
"package-not-child-with-unconfirmed-parents");
return PackageMempoolAcceptResult(package_state, {});
}
// Protect against bugs where we pull more inputs from disk that miss being
// added to coins_to_uncache. The backend will be connected again when
// needed in PreChecks.
m_view.SetBackend(m_dummy);
LOCK(m_pool.cs);
std::map<const TxId, const MempoolAcceptResult> results;
// Node operators are free to set their mempool policies however they
// please, nodes may receive transactions in different orders, and malicious
// counterparties may try to take advantage of policy differences to pin or
// delay propagation of transactions. As such, it's possible for some
// package transaction(s) to already be in the mempool, and we don't want to
// reject the entire package in that case (as that could be a censorship
// vector). De-duplicate the transactions that are already in the mempool,
// and only call AcceptMultipleTransactions() with the new transactions.
// This ensures we don't double-count transaction counts and sizes when
// checking ancestor/descendant limits, or double-count transaction fees for
// fee-related policy.
std::vector<CTransactionRef> txns_new;
for (const auto &tx : package) {
const auto &txid = tx->GetId();
// An already confirmed tx is treated as one not in mempool, because all
// we know is that the inputs aren't available.
if (m_pool.exists(txid)) {
// Exact transaction already exists in the mempool.
auto iter = m_pool.GetIter(txid);
assert(iter != std::nullopt);
results.emplace(txid, MempoolAcceptResult::MempoolTx(
(*iter.value())->GetTxSize(),
(*iter.value())->GetFee()));
} else {
// Transaction does not already exist in the mempool.
txns_new.push_back(tx);
}
}
// Nothing to do if the entire package has already been submitted.
if (txns_new.empty()) {
return PackageMempoolAcceptResult(package_state, std::move(results));
}
// Validate the (deduplicated) transactions as a package.
auto submission_result = AcceptMultipleTransactions(txns_new, args);
// Include already-in-mempool transaction results in the final result.
for (const auto &[txid, mempoolaccept_res] : results) {
submission_result.m_tx_results.emplace(txid, mempoolaccept_res);
}
return submission_result;
}
} // namespace
MempoolAcceptResult AcceptToMemoryPool(Chainstate &active_chainstate,
const CTransactionRef &tx,
int64_t accept_time, bool bypass_limits,
bool test_accept,
unsigned int heightOverride) {
AssertLockHeld(::cs_main);
assert(active_chainstate.GetMempool() != nullptr);
CTxMemPool &pool{*active_chainstate.GetMempool()};
std::vector<COutPoint> coins_to_uncache;
auto args = MemPoolAccept::ATMPArgs::SingleAccept(
active_chainstate.m_chainman.GetConfig(), accept_time, bypass_limits,
coins_to_uncache, test_accept, heightOverride);
const MempoolAcceptResult result = MemPoolAccept(pool, active_chainstate)
.AcceptSingleTransaction(tx, args);
if (result.m_result_type != MempoolAcceptResult::ResultType::VALID) {
// Remove coins that were not present in the coins cache before calling
// ATMPW; this is to prevent memory DoS in case we receive a large
// number of invalid transactions that attempt to overrun the in-memory
// coins cache
// (`CCoinsViewCache::cacheCoins`).
for (const COutPoint &outpoint : coins_to_uncache) {
active_chainstate.CoinsTip().Uncache(outpoint);
}
}
// After we've (potentially) uncached entries, ensure our coins cache is
// still within its size limits
BlockValidationState stateDummy;
active_chainstate.FlushStateToDisk(stateDummy, FlushStateMode::PERIODIC);
return result;
}
PackageMempoolAcceptResult ProcessNewPackage(Chainstate &active_chainstate,
CTxMemPool &pool,
const Package &package,
bool test_accept) {
AssertLockHeld(cs_main);
assert(!package.empty());
assert(std::all_of(package.cbegin(), package.cend(),
[](const auto &tx) { return tx != nullptr; }));
const Config &config = active_chainstate.m_chainman.GetConfig();
std::vector<COutPoint> coins_to_uncache;
const auto result = [&]() EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
AssertLockHeld(cs_main);
if (test_accept) {
auto args = MemPoolAccept::ATMPArgs::PackageTestAccept(
config, GetTime(), coins_to_uncache);
return MemPoolAccept(pool, active_chainstate)
.AcceptMultipleTransactions(package, args);
} else {
auto args = MemPoolAccept::ATMPArgs::PackageChildWithParents(
config, GetTime(), coins_to_uncache);
return MemPoolAccept(pool, active_chainstate)
.AcceptPackage(package, args);
}
}();
// Uncache coins pertaining to transactions that were not submitted to the
// mempool.
if (test_accept || result.m_state.IsInvalid()) {
for (const COutPoint &hashTx : coins_to_uncache) {
active_chainstate.CoinsTip().Uncache(hashTx);
}
}
// Ensure the coins cache is still within limits.
BlockValidationState state_dummy;
active_chainstate.FlushStateToDisk(state_dummy, FlushStateMode::PERIODIC);
return result;
}
Amount GetBlockSubsidy(int nHeight, const Consensus::Params &consensusParams) {
int halvings = nHeight / consensusParams.nSubsidyHalvingInterval;
// Force block reward to zero when right shift is undefined.
if (halvings >= 64) {
return Amount::zero();
}
Amount nSubsidy = 50 * COIN;
// Subsidy is cut in half every 210,000 blocks which will occur
// approximately every 4 years.
return ((nSubsidy / SATOSHI) >> halvings) * SATOSHI;
}
CoinsViews::CoinsViews(DBParams db_params, CoinsViewOptions options)
: m_dbview{std::move(db_params), std::move(options)},
m_catcherview(&m_dbview) {}
void CoinsViews::InitCache() {
AssertLockHeld(::cs_main);
m_cacheview = std::make_unique<CCoinsViewCache>(&m_catcherview);
}
Chainstate::Chainstate(CTxMemPool *mempool, BlockManager &blockman,
ChainstateManager &chainman,
std::optional<BlockHash> from_snapshot_blockhash)
: m_mempool(mempool), m_blockman(blockman), m_chainman(chainman),
m_from_snapshot_blockhash(from_snapshot_blockhash) {}
void Chainstate::InitCoinsDB(size_t cache_size_bytes, bool in_memory,
bool should_wipe, std::string leveldb_name) {
if (m_from_snapshot_blockhash) {
leveldb_name += node::SNAPSHOT_CHAINSTATE_SUFFIX;
}
m_coins_views = std::make_unique<CoinsViews>(
DBParams{.path = m_chainman.m_options.datadir / leveldb_name,
.cache_bytes = cache_size_bytes,
.memory_only = in_memory,
.wipe_data = should_wipe,
.obfuscate = true,
.options = m_chainman.m_options.coins_db},
m_chainman.m_options.coins_view);
}
void Chainstate::InitCoinsCache(size_t cache_size_bytes) {
AssertLockHeld(::cs_main);
assert(m_coins_views != nullptr);
m_coinstip_cache_size_bytes = cache_size_bytes;
m_coins_views->InitCache();
}
// Note that though this is marked const, we may end up modifying
// `m_cached_finished_ibd`, which is a performance-related implementation
// detail. This function must be marked `const` so that `CValidationInterface`
// clients (which are given a `const Chainstate*`) can call it.
//
bool Chainstate::IsInitialBlockDownload() const {
// Optimization: pre-test latch before taking the lock.
if (m_cached_finished_ibd.load(std::memory_order_relaxed)) {
return false;
}
LOCK(cs_main);
if (m_cached_finished_ibd.load(std::memory_order_relaxed)) {
return false;
}
if (m_chainman.m_blockman.LoadingBlocks()) {
return true;
}
if (m_chain.Tip() == nullptr) {
return true;
}
if (m_chain.Tip()->nChainWork < m_chainman.MinimumChainWork()) {
return true;
}
if (m_chain.Tip()->Time() <
Now<NodeSeconds>() - m_chainman.m_options.max_tip_age) {
return true;
}
LogPrintf("Leaving InitialBlockDownload (latching to false)\n");
m_cached_finished_ibd.store(true, std::memory_order_relaxed);
return false;
}
void Chainstate::CheckForkWarningConditions() {
AssertLockHeld(cs_main);
// Before we get past initial download, we cannot reliably alert about forks
// (we assume we don't get stuck on a fork before finishing our initial
// sync)
if (IsInitialBlockDownload()) {
return;
}
// If our best fork is no longer within 72 blocks (+/- 12 hours if no one
// mines it) of our head, or if it is back on the active chain, drop it
if (m_best_fork_tip && (m_chain.Height() - m_best_fork_tip->nHeight >= 72 ||
m_chain.Contains(m_best_fork_tip))) {
m_best_fork_tip = nullptr;
}
if (m_best_fork_tip ||
(m_chainman.m_best_invalid &&
m_chainman.m_best_invalid->nChainWork >
m_chain.Tip()->nChainWork + (GetBlockProof(*m_chain.Tip()) * 6))) {
if (!GetfLargeWorkForkFound() && m_best_fork_base) {
std::string warning =
std::string("'Warning: Large-work fork detected, forking after "
"block ") +
m_best_fork_base->phashBlock->ToString() + std::string("'");
m_chainman.GetNotifications().warning(warning);
}
if (m_best_fork_tip && m_best_fork_base) {
LogPrintf("%s: Warning: Large fork found\n forking the "
"chain at height %d (%s)\n lasting to height %d "
"(%s).\nChain state database corruption likely.\n",
__func__, m_best_fork_base->nHeight,
m_best_fork_base->phashBlock->ToString(),
m_best_fork_tip->nHeight,
m_best_fork_tip->phashBlock->ToString());
SetfLargeWorkForkFound(true);
} else {
LogPrintf("%s: Warning: Found invalid chain at least ~6 blocks "
"longer than our best chain.\nChain state database "
"corruption likely.\n",
__func__);
SetfLargeWorkInvalidChainFound(true);
}
} else {
SetfLargeWorkForkFound(false);
SetfLargeWorkInvalidChainFound(false);
}
}
void Chainstate::CheckForkWarningConditionsOnNewFork(
CBlockIndex *pindexNewForkTip) {
AssertLockHeld(cs_main);
// If we are on a fork that is sufficiently large, set a warning flag.
const CBlockIndex *pfork = m_chain.FindFork(pindexNewForkTip);
// We define a condition where we should warn the user about as a fork of at
// least 7 blocks with a tip within 72 blocks (+/- 12 hours if no one mines
// it) of ours. We use 7 blocks rather arbitrarily as it represents just
// under 10% of sustained network hash rate operating on the fork, or a
// chain that is entirely longer than ours and invalid (note that this
// should be detected by both). We define it this way because it allows us
// to only store the highest fork tip (+ base) which meets the 7-block
// condition and from this always have the most-likely-to-cause-warning fork
if (pfork &&
(!m_best_fork_tip ||
pindexNewForkTip->nHeight > m_best_fork_tip->nHeight) &&
pindexNewForkTip->nChainWork - pfork->nChainWork >
(GetBlockProof(*pfork) * 7) &&
m_chain.Height() - pindexNewForkTip->nHeight < 72) {
m_best_fork_tip = pindexNewForkTip;
m_best_fork_base = pfork;
}
CheckForkWarningConditions();
}
// Called both upon regular invalid block discovery *and* InvalidateBlock
void Chainstate::InvalidChainFound(CBlockIndex *pindexNew) {
AssertLockHeld(cs_main);
if (!m_chainman.m_best_invalid ||
pindexNew->nChainWork > m_chainman.m_best_invalid->nChainWork) {
m_chainman.m_best_invalid = pindexNew;
}
if (m_chainman.m_best_header != nullptr &&
m_chainman.m_best_header->GetAncestor(pindexNew->nHeight) ==
pindexNew) {
m_chainman.m_best_header = m_chain.Tip();
}
// If the invalid chain found is supposed to be finalized, we need to move
// back the finalization point.
if (IsBlockAvalancheFinalized(pindexNew)) {
LOCK(cs_avalancheFinalizedBlockIndex);
m_avalancheFinalizedBlockIndex = pindexNew->pprev;
}
LogPrintf("%s: invalid block=%s height=%d log2_work=%f date=%s\n",
__func__, pindexNew->GetBlockHash().ToString(),
pindexNew->nHeight,
log(pindexNew->nChainWork.getdouble()) / log(2.0),
FormatISO8601DateTime(pindexNew->GetBlockTime()));
CBlockIndex *tip = m_chain.Tip();
assert(tip);
LogPrintf("%s: current best=%s height=%d log2_work=%f date=%s\n",
__func__, tip->GetBlockHash().ToString(), m_chain.Height(),
log(tip->nChainWork.getdouble()) / log(2.0),
FormatISO8601DateTime(tip->GetBlockTime()));
}
// Same as InvalidChainFound, above, except not called directly from
// InvalidateBlock, which does its own setBlockIndexCandidates management.
void Chainstate::InvalidBlockFound(CBlockIndex *pindex,
const BlockValidationState &state) {
AssertLockHeld(cs_main);
if (state.GetResult() != BlockValidationResult::BLOCK_MUTATED) {
pindex->nStatus = pindex->nStatus.withFailed();
m_chainman.m_failed_blocks.insert(pindex);
m_blockman.m_dirty_blockindex.insert(pindex);
InvalidChainFound(pindex);
}
}
void SpendCoins(CCoinsViewCache &view, const CTransaction &tx, CTxUndo &txundo,
int nHeight) {
// Mark inputs spent.
if (tx.IsCoinBase()) {
return;
}
txundo.vprevout.reserve(tx.vin.size());
for (const CTxIn &txin : tx.vin) {
txundo.vprevout.emplace_back();
bool is_spent = view.SpendCoin(txin.prevout, &txundo.vprevout.back());
assert(is_spent);
}
}
void UpdateCoins(CCoinsViewCache &view, const CTransaction &tx, CTxUndo &txundo,
int nHeight) {
SpendCoins(view, tx, txundo, nHeight);
AddCoins(view, tx, nHeight);
}
bool CScriptCheck::operator()() {
const CScript &scriptSig = ptxTo->vin[nIn].scriptSig;
if (!VerifyScript(scriptSig, m_tx_out.scriptPubKey, nFlags,
CachingTransactionSignatureChecker(
ptxTo, nIn, m_tx_out.nValue, cacheStore, txdata),
metrics, &error)) {
return false;
}
if ((pTxLimitSigChecks &&
!pTxLimitSigChecks->consume_and_check(metrics.nSigChecks)) ||
(pBlockLimitSigChecks &&
!pBlockLimitSigChecks->consume_and_check(metrics.nSigChecks))) {
// we can't assign a meaningful script error (since the script
// succeeded), but remove the ScriptError::OK which could be
// misinterpreted.
error = ScriptError::SIGCHECKS_LIMIT_EXCEEDED;
return false;
}
return true;
}
bool CheckInputScripts(const CTransaction &tx, TxValidationState &state,
const CCoinsViewCache &inputs, const uint32_t flags,
bool sigCacheStore, bool scriptCacheStore,
const PrecomputedTransactionData &txdata,
int &nSigChecksOut, TxSigCheckLimiter &txLimitSigChecks,
CheckInputsLimiter *pBlockLimitSigChecks,
std::vector<CScriptCheck> *pvChecks) {
AssertLockHeld(cs_main);
assert(!tx.IsCoinBase());
if (pvChecks) {
pvChecks->reserve(tx.vin.size());
}
// First check if script executions have been cached with the same flags.
// Note that this assumes that the inputs provided are correct (ie that the
// transaction hash which is in tx's prevouts properly commits to the
// scriptPubKey in the inputs view of that transaction).
ScriptCacheKey hashCacheEntry(tx, flags);
if (IsKeyInScriptCache(hashCacheEntry, !scriptCacheStore, nSigChecksOut)) {
if (!txLimitSigChecks.consume_and_check(nSigChecksOut) ||
(pBlockLimitSigChecks &&
!pBlockLimitSigChecks->consume_and_check(nSigChecksOut))) {
return state.Invalid(TxValidationResult::TX_CONSENSUS,
"too-many-sigchecks");
}
return true;
}
int nSigChecksTotal = 0;
for (size_t i = 0; i < tx.vin.size(); i++) {
const COutPoint &prevout = tx.vin[i].prevout;
const Coin &coin = inputs.AccessCoin(prevout);
assert(!coin.IsSpent());
// We very carefully only pass in things to CScriptCheck which are
// clearly committed to by tx's hash. This provides a sanity
// check that our caching is not introducing consensus failures through
// additional data in, eg, the coins being spent being checked as a part
// of CScriptCheck.
// Verify signature
CScriptCheck check(coin.GetTxOut(), tx, i, flags, sigCacheStore, txdata,
&txLimitSigChecks, pBlockLimitSigChecks);
// If pvChecks is not null, defer the check execution to the caller.
if (pvChecks) {
pvChecks->push_back(std::move(check));
continue;
}
if (!check()) {
ScriptError scriptError = check.GetScriptError();
// Compute flags without the optional standardness flags.
// This differs from MANDATORY_SCRIPT_VERIFY_FLAGS as it contains
// additional upgrade flags (see AcceptToMemoryPoolWorker variable
// extraFlags).
uint32_t mandatoryFlags =
flags & ~STANDARD_NOT_MANDATORY_VERIFY_FLAGS;
if (flags != mandatoryFlags) {
// Check whether the failure was caused by a non-mandatory
// script verification check. If so, ensure we return
// NOT_STANDARD instead of CONSENSUS to avoid downstream users
// splitting the network between upgraded and non-upgraded nodes
// by banning CONSENSUS-failing data providers.
CScriptCheck check2(coin.GetTxOut(), tx, i, mandatoryFlags,
sigCacheStore, txdata);
if (check2()) {
return state.Invalid(
TxValidationResult::TX_NOT_STANDARD,
strprintf("non-mandatory-script-verify-flag (%s)",
ScriptErrorString(scriptError)));
}
// update the error message to reflect the mandatory violation.
scriptError = check2.GetScriptError();
}
// MANDATORY flag failures correspond to
// TxValidationResult::TX_CONSENSUS. Because CONSENSUS failures are
// the most serious case of validation failures, we may need to
// consider using RECENT_CONSENSUS_CHANGE for any script failure
// that could be due to non-upgraded nodes which we may want to
// support, to avoid splitting the network (but this depends on the
// details of how net_processing handles such errors).
return state.Invalid(
TxValidationResult::TX_CONSENSUS,
strprintf("mandatory-script-verify-flag-failed (%s)",
ScriptErrorString(scriptError)));
}
nSigChecksTotal += check.GetScriptExecutionMetrics().nSigChecks;
}
nSigChecksOut = nSigChecksTotal;
if (scriptCacheStore && !pvChecks) {
// We executed all of the provided scripts, and were told to cache the
// result. Do so now.
AddKeyInScriptCache(hashCacheEntry, nSigChecksTotal);
}
return true;
}
bool AbortNode(BlockValidationState &state, const std::string &strMessage,
const bilingual_str &userMessage) {
AbortNode(strMessage, userMessage);
return state.Error(strMessage);
}
/** Restore the UTXO in a Coin at a given COutPoint. */
DisconnectResult UndoCoinSpend(Coin &&undo, CCoinsViewCache &view,
const COutPoint &out) {
bool fClean = true;
if (view.HaveCoin(out)) {
// Overwriting transaction output.
fClean = false;
}
if (undo.GetHeight() == 0) {
// Missing undo metadata (height and coinbase). Older versions included
// this information only in undo records for the last spend of a
// transactions' outputs. This implies that it must be present for some
// other output of the same tx.
const Coin &alternate = AccessByTxid(view, out.GetTxId());
if (alternate.IsSpent()) {
// Adding output for transaction without known metadata
return DisconnectResult::FAILED;
}
// This is somewhat ugly, but hopefully utility is limited. This is only
// useful when working from legacy on disck data. In any case, putting
// the correct information in there doesn't hurt.
const_cast<Coin &>(undo) = Coin(undo.GetTxOut(), alternate.GetHeight(),
alternate.IsCoinBase());
}
// If the coin already exists as an unspent coin in the cache, then the
// possible_overwrite parameter to AddCoin must be set to true. We have
// already checked whether an unspent coin exists above using HaveCoin, so
// we don't need to guess. When fClean is false, an unspent coin already
// existed and it is an overwrite.
view.AddCoin(out, std::move(undo), !fClean);
return fClean ? DisconnectResult::OK : DisconnectResult::UNCLEAN;
}
/**
* Undo the effects of this block (with given index) on the UTXO set represented
* by coins. When FAILED is returned, view is left in an indeterminate state.
*/
DisconnectResult Chainstate::DisconnectBlock(const CBlock &block,
const CBlockIndex *pindex,
CCoinsViewCache &view) {
AssertLockHeld(::cs_main);
CBlockUndo blockUndo;
if (!m_blockman.UndoReadFromDisk(blockUndo, *pindex)) {
error("DisconnectBlock(): failure reading undo data");
return DisconnectResult::FAILED;
}
return ApplyBlockUndo(std::move(blockUndo), block, pindex, view);
}
DisconnectResult ApplyBlockUndo(CBlockUndo &&blockUndo, const CBlock &block,
const CBlockIndex *pindex,
CCoinsViewCache &view) {
bool fClean = true;
if (blockUndo.vtxundo.size() + 1 != block.vtx.size()) {
error("DisconnectBlock(): block and undo data inconsistent");
return DisconnectResult::FAILED;
}
// First, restore inputs.
for (size_t i = 1; i < block.vtx.size(); i++) {
const CTransaction &tx = *(block.vtx[i]);
CTxUndo &txundo = blockUndo.vtxundo[i - 1];
if (txundo.vprevout.size() != tx.vin.size()) {
error("DisconnectBlock(): transaction and undo data inconsistent");
return DisconnectResult::FAILED;
}
for (size_t j = 0; j < tx.vin.size(); j++) {
const COutPoint &out = tx.vin[j].prevout;
DisconnectResult res =
UndoCoinSpend(std::move(txundo.vprevout[j]), view, out);
if (res == DisconnectResult::FAILED) {
return DisconnectResult::FAILED;
}
fClean = fClean && res != DisconnectResult::UNCLEAN;
}
// At this point, all of txundo.vprevout should have been moved out.
}
// Second, revert created outputs.
for (const auto &ptx : block.vtx) {
const CTransaction &tx = *ptx;
const TxId &txid = tx.GetId();
const bool is_coinbase = tx.IsCoinBase();
// Check that all outputs are available and match the outputs in the
// block itself exactly.
for (size_t o = 0; o < tx.vout.size(); o++) {
if (tx.vout[o].scriptPubKey.IsUnspendable()) {
continue;
}
COutPoint out(txid, o);
Coin coin;
bool is_spent = view.SpendCoin(out, &coin);
if (!is_spent || tx.vout[o] != coin.GetTxOut() ||
uint32_t(pindex->nHeight) != coin.GetHeight() ||
is_coinbase != coin.IsCoinBase()) {
// transaction output mismatch
fClean = false;
}
}
}
// Move best block pointer to previous block.
view.SetBestBlock(block.hashPrevBlock);
return fClean ? DisconnectResult::OK : DisconnectResult::UNCLEAN;
}
static CCheckQueue<CScriptCheck> scriptcheckqueue(128);
void StartScriptCheckWorkerThreads(int threads_num) {
scriptcheckqueue.StartWorkerThreads(threads_num);
}
void StopScriptCheckWorkerThreads() {
scriptcheckqueue.StopWorkerThreads();
}
// Returns the script flags which should be checked for the block after
// the given block.
static uint32_t GetNextBlockScriptFlags(const CBlockIndex *pindex,
const ChainstateManager &chainman) {
const Consensus::Params &consensusparams = chainman.GetConsensus();
uint32_t flags = SCRIPT_VERIFY_NONE;
// Enforce P2SH (BIP16)
if (DeploymentActiveAfter(pindex, chainman, Consensus::DEPLOYMENT_P2SH)) {
flags |= SCRIPT_VERIFY_P2SH;
}
// Enforce the DERSIG (BIP66) rule.
if (DeploymentActiveAfter(pindex, chainman, Consensus::DEPLOYMENT_DERSIG)) {
flags |= SCRIPT_VERIFY_DERSIG;
}
// Start enforcing CHECKLOCKTIMEVERIFY (BIP65) rule.
if (DeploymentActiveAfter(pindex, chainman, Consensus::DEPLOYMENT_CLTV)) {
flags |= SCRIPT_VERIFY_CHECKLOCKTIMEVERIFY;
}
// Start enforcing CSV (BIP68, BIP112 and BIP113) rule.
if (DeploymentActiveAfter(pindex, chainman, Consensus::DEPLOYMENT_CSV)) {
flags |= SCRIPT_VERIFY_CHECKSEQUENCEVERIFY;
}
// If the UAHF is enabled, we start accepting replay protected txns
if (IsUAHFenabled(consensusparams, pindex)) {
flags |= SCRIPT_VERIFY_STRICTENC;
flags |= SCRIPT_ENABLE_SIGHASH_FORKID;
}
// If the DAA HF is enabled, we start rejecting transaction that use a high
// s in their signature. We also make sure that signature that are supposed
// to fail (for instance in multisig or other forms of smart contracts) are
// null.
if (IsDAAEnabled(consensusparams, pindex)) {
flags |= SCRIPT_VERIFY_LOW_S;
flags |= SCRIPT_VERIFY_NULLFAIL;
}
// When the magnetic anomaly fork is enabled, we start accepting
// transactions using the OP_CHECKDATASIG opcode and it's verify
// alternative. We also start enforcing push only signatures and
// clean stack.
if (IsMagneticAnomalyEnabled(consensusparams, pindex)) {
flags |= SCRIPT_VERIFY_SIGPUSHONLY;
flags |= SCRIPT_VERIFY_CLEANSTACK;
}
if (IsGravitonEnabled(consensusparams, pindex)) {
flags |= SCRIPT_ENABLE_SCHNORR_MULTISIG;
flags |= SCRIPT_VERIFY_MINIMALDATA;
}
if (IsPhononEnabled(consensusparams, pindex)) {
flags |= SCRIPT_ENFORCE_SIGCHECKS;
}
// We make sure this node will have replay protection during the next hard
// fork.
if (IsReplayProtectionEnabled(consensusparams, pindex)) {
flags |= SCRIPT_ENABLE_REPLAY_PROTECTION;
}
return flags;
}
static int64_t nTimeCheck = 0;
static int64_t nTimeForks = 0;
static int64_t nTimeVerify = 0;
static int64_t nTimeConnect = 0;
static int64_t nTimeIndex = 0;
static int64_t nTimeTotal = 0;
static int64_t nBlocksTotal = 0;
/**
* Apply the effects of this block (with given index) on the UTXO set
* represented by coins. Validity checks that depend on the UTXO set are also
* done; ConnectBlock() can fail if those validity checks fail (among other
* reasons).
*/
bool Chainstate::ConnectBlock(const CBlock &block, BlockValidationState &state,
CBlockIndex *pindex, CCoinsViewCache &view,
BlockValidationOptions options, Amount *blockFees,
bool fJustCheck) {
AssertLockHeld(cs_main);
assert(pindex);
const BlockHash block_hash{block.GetHash()};
assert(*pindex->phashBlock == block_hash);
int64_t nTimeStart = GetTimeMicros();
const CChainParams ¶ms{m_chainman.GetParams()};
const Consensus::Params &consensusParams = params.GetConsensus();
// Check it again in case a previous version let a bad block in
// NOTE: We don't currently (re-)invoke ContextualCheckBlock() or
// ContextualCheckBlockHeader() here. This means that if we add a new
// consensus rule that is enforced in one of those two functions, then we
// may have let in a block that violates the rule prior to updating the
// software, and we would NOT be enforcing the rule here. Fully solving
// upgrade from one software version to the next after a consensus rule
// change is potentially tricky and issue-specific.
// Also, currently the rule against blocks more than 2 hours in the future
// is enforced in ContextualCheckBlockHeader(); we wouldn't want to
// re-enforce that rule here (at least until we make it impossible for
// m_adjusted_time_callback() to go backward).
if (!CheckBlock(block, state, consensusParams,
options.withCheckPoW(!fJustCheck)
.withCheckMerkleRoot(!fJustCheck))) {
if (state.GetResult() == BlockValidationResult::BLOCK_MUTATED) {
// We don't write down blocks to disk if they may have been
// corrupted, so this should be impossible unless we're having
// hardware problems.
return AbortNode(state, "Corrupt block found indicating potential "
"hardware failure; shutting down");
}
return error("%s: Consensus::CheckBlock: %s", __func__,
state.ToString());
}
// Verify that the view's current state corresponds to the previous block
BlockHash hashPrevBlock =
pindex->pprev == nullptr ? BlockHash() : pindex->pprev->GetBlockHash();
assert(hashPrevBlock == view.GetBestBlock());
nBlocksTotal++;
// Special case for the genesis block, skipping connection of its
// transactions (its coinbase is unspendable)
if (block_hash == consensusParams.hashGenesisBlock) {
if (!fJustCheck) {
view.SetBestBlock(pindex->GetBlockHash());
}
return true;
}
bool fScriptChecks = true;
if (!m_chainman.AssumedValidBlock().IsNull()) {
// We've been configured with the hash of a block which has been
// externally verified to have a valid history. A suitable default value
// is included with the software and updated from time to time. Because
// validity relative to a piece of software is an objective fact these
// defaults can be easily reviewed. This setting doesn't force the
// selection of any particular chain but makes validating some faster by
// effectively caching the result of part of the verification.
BlockMap::const_iterator it{
m_blockman.m_block_index.find(m_chainman.AssumedValidBlock())};
if (it != m_blockman.m_block_index.end()) {
if (it->second.GetAncestor(pindex->nHeight) == pindex &&
m_chainman.m_best_header->GetAncestor(pindex->nHeight) ==
pindex &&
m_chainman.m_best_header->nChainWork >=
m_chainman.MinimumChainWork()) {
// This block is a member of the assumed verified chain and an
// ancestor of the best header.
// Script verification is skipped when connecting blocks under
// the assumevalid block. Assuming the assumevalid block is
// valid this is safe because block merkle hashes are still
// computed and checked, Of course, if an assumed valid block is
// invalid due to false scriptSigs this optimization would allow
// an invalid chain to be accepted.
// The equivalent time check discourages hash power from
// extorting the network via DOS attack into accepting an
// invalid block through telling users they must manually set
// assumevalid. Requiring a software change or burying the
// invalid block, regardless of the setting, makes it hard to
// hide the implication of the demand. This also avoids having
// release candidates that are hardly doing any signature
// verification at all in testing without having to artificially
// set the default assumed verified block further back. The test
// against the minimum chain work prevents the skipping when
// denied access to any chain at least as good as the expected
// chain.
fScriptChecks = (GetBlockProofEquivalentTime(
*m_chainman.m_best_header, *pindex,
*m_chainman.m_best_header,
consensusParams) <= 60 * 60 * 24 * 7 * 2);
}
}
}
int64_t nTime1 = GetTimeMicros();
nTimeCheck += nTime1 - nTimeStart;
LogPrint(BCLog::BENCH, " - Sanity checks: %.2fms [%.2fs (%.2fms/blk)]\n",
MILLI * (nTime1 - nTimeStart), nTimeCheck * MICRO,
nTimeCheck * MILLI / nBlocksTotal);
// Do not allow blocks that contain transactions which 'overwrite' older
// transactions, unless those are already completely spent. If such
// overwrites are allowed, coinbases and transactions depending upon those
// can be duplicated to remove the ability to spend the first instance --
// even after being sent to another address.
// See BIP30, CVE-2012-1909, and http://r6.ca/blog/20120206T005236Z.html
// for more information. This rule was originally applied to all blocks
// with a timestamp after March 15, 2012, 0:00 UTC. Now that the whole
// chain is irreversibly beyond that time it is applied to all blocks
// except the two in the chain that violate it. This prevents exploiting
// the issue against nodes during their initial block download.
bool fEnforceBIP30 = !((pindex->nHeight == 91842 &&
pindex->GetBlockHash() ==
uint256S("0x00000000000a4d0a398161ffc163c503763"
"b1f4360639393e0e4c8e300e0caec")) ||
(pindex->nHeight == 91880 &&
pindex->GetBlockHash() ==
uint256S("0x00000000000743f190a18c5577a3c2d2a1f"
"610ae9601ac046a38084ccb7cd721")));
// Once BIP34 activated it was not possible to create new duplicate
// coinbases and thus other than starting with the 2 existing duplicate
// coinbase pairs, not possible to create overwriting txs. But by the time
// BIP34 activated, in each of the existing pairs the duplicate coinbase had
// overwritten the first before the first had been spent. Since those
// coinbases are sufficiently buried it's no longer possible to create
// further duplicate transactions descending from the known pairs either. If
// we're on the known chain at height greater than where BIP34 activated, we
// can save the db accesses needed for the BIP30 check.
// BIP34 requires that a block at height X (block X) has its coinbase
// scriptSig start with a CScriptNum of X (indicated height X). The above
// logic of no longer requiring BIP30 once BIP34 activates is flawed in the
// case that there is a block X before the BIP34 height of 227,931 which has
// an indicated height Y where Y is greater than X. The coinbase for block
// X would also be a valid coinbase for block Y, which could be a BIP30
// violation. An exhaustive search of all mainnet coinbases before the
// BIP34 height which have an indicated height greater than the block height
// reveals many occurrences. The 3 lowest indicated heights found are
// 209,921, 490,897, and 1,983,702 and thus coinbases for blocks at these 3
// heights would be the first opportunity for BIP30 to be violated.
// The search reveals a great many blocks which have an indicated height
// greater than 1,983,702, so we simply remove the optimization to skip
// BIP30 checking for blocks at height 1,983,702 or higher. Before we reach
// that block in another 25 years or so, we should take advantage of a
// future consensus change to do a new and improved version of BIP34 that
// will actually prevent ever creating any duplicate coinbases in the
// future.
static constexpr int BIP34_IMPLIES_BIP30_LIMIT = 1983702;
// There is no potential to create a duplicate coinbase at block 209,921
// because this is still before the BIP34 height and so explicit BIP30
// checking is still active.
// The final case is block 176,684 which has an indicated height of
// 490,897. Unfortunately, this issue was not discovered until about 2 weeks
// before block 490,897 so there was not much opportunity to address this
// case other than to carefully analyze it and determine it would not be a
// problem. Block 490,897 was, in fact, mined with a different coinbase than
// block 176,684, but it is important to note that even if it hadn't been or
// is remined on an alternate fork with a duplicate coinbase, we would still
// not run into a BIP30 violation. This is because the coinbase for 176,684
// is spent in block 185,956 in transaction
// d4f7fbbf92f4a3014a230b2dc70b8058d02eb36ac06b4a0736d9d60eaa9e8781. This
// spending transaction can't be duplicated because it also spends coinbase
// 0328dd85c331237f18e781d692c92de57649529bd5edf1d01036daea32ffde29. This
// coinbase has an indicated height of over 4.2 billion, and wouldn't be
// duplicatable until that height, and it's currently impossible to create a
// chain that long. Nevertheless we may wish to consider a future soft fork
// which retroactively prevents block 490,897 from creating a duplicate
// coinbase. The two historical BIP30 violations often provide a confusing
// edge case when manipulating the UTXO and it would be simpler not to have
// another edge case to deal with.
// testnet3 has no blocks before the BIP34 height with indicated heights
// post BIP34 before approximately height 486,000,000 and presumably will
// be reset before it reaches block 1,983,702 and starts doing unnecessary
// BIP30 checking again.
assert(pindex->pprev);
CBlockIndex *pindexBIP34height =
pindex->pprev->GetAncestor(consensusParams.BIP34Height);
// Only continue to enforce if we're below BIP34 activation height or the
// block hash at that height doesn't correspond.
fEnforceBIP30 =
fEnforceBIP30 &&
(!pindexBIP34height ||
!(pindexBIP34height->GetBlockHash() == consensusParams.BIP34Hash));
// TODO: Remove BIP30 checking from block height 1,983,702 on, once we have
// a consensus change that ensures coinbases at those heights can not
// duplicate earlier coinbases.
if (fEnforceBIP30 || pindex->nHeight >= BIP34_IMPLIES_BIP30_LIMIT) {
for (const auto &tx : block.vtx) {
for (size_t o = 0; o < tx->vout.size(); o++) {
if (view.HaveCoin(COutPoint(tx->GetId(), o))) {
LogPrintf("ERROR: ConnectBlock(): tried to overwrite "
"transaction\n");
return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS,
"bad-txns-BIP30");
}
}
}
}
// Enforce BIP68 (sequence locks).
int nLockTimeFlags = 0;
if (DeploymentActiveAt(*pindex, consensusParams,
Consensus::DEPLOYMENT_CSV)) {
nLockTimeFlags |= LOCKTIME_VERIFY_SEQUENCE;
}
const uint32_t flags = GetNextBlockScriptFlags(pindex->pprev, m_chainman);
int64_t nTime2 = GetTimeMicros();
nTimeForks += nTime2 - nTime1;
LogPrint(BCLog::BENCH, " - Fork checks: %.2fms [%.2fs (%.2fms/blk)]\n",
MILLI * (nTime2 - nTime1), nTimeForks * MICRO,
nTimeForks * MILLI / nBlocksTotal);
std::vector<int> prevheights;
Amount nFees = Amount::zero();
int nInputs = 0;
// Limit the total executed signature operations in the block, a consensus
// rule. Tracking during the CPU-consuming part (validation of uncached
// inputs) is per-input atomic and validation in each thread stops very
// quickly after the limit is exceeded, so an adversary cannot cause us to
// exceed the limit by much at all.
CheckInputsLimiter nSigChecksBlockLimiter(
GetMaxBlockSigChecksCount(options.getExcessiveBlockSize()));
std::vector<TxSigCheckLimiter> nSigChecksTxLimiters;
nSigChecksTxLimiters.resize(block.vtx.size() - 1);
CBlockUndo blockundo;
blockundo.vtxundo.resize(block.vtx.size() - 1);
CCheckQueueControl<CScriptCheck> control(fScriptChecks ? &scriptcheckqueue
: nullptr);
// Add all outputs
try {
for (const auto &ptx : block.vtx) {
AddCoins(view, *ptx, pindex->nHeight);
}
} catch (const std::logic_error &e) {
// This error will be thrown from AddCoin if we try to connect a block
// containing duplicate transactions. Such a thing should normally be
// caught early nowadays (due to ContextualCheckBlock's CTOR
// enforcement) however some edge cases can escape that:
// - ContextualCheckBlock does not get re-run after saving the block to
// disk, and older versions may have saved a weird block.
// - its checks are not applied to pre-CTOR chains, which we might visit
// with checkpointing off.
LogPrintf("ERROR: ConnectBlock(): tried to overwrite transaction\n");
return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS,
"tx-duplicate");
}
size_t txIndex = 0;
// nSigChecksRet may be accurate (found in cache) or 0 (checks were
// deferred into vChecks).
int nSigChecksRet;
for (const auto &ptx : block.vtx) {
const CTransaction &tx = *ptx;
const bool isCoinBase = tx.IsCoinBase();
nInputs += tx.vin.size();
{
Amount txfee = Amount::zero();
TxValidationState tx_state;
if (!isCoinBase &&
!Consensus::CheckTxInputs(tx, tx_state, view, pindex->nHeight,
txfee)) {
// Any transaction validation failure in ConnectBlock is a block
// consensus failure.
state.Invalid(BlockValidationResult::BLOCK_CONSENSUS,
tx_state.GetRejectReason(),
tx_state.GetDebugMessage());
return error("%s: Consensus::CheckTxInputs: %s, %s", __func__,
tx.GetId().ToString(), state.ToString());
}
nFees += txfee;
}
if (!MoneyRange(nFees)) {
LogPrintf("ERROR: %s: accumulated fee in the block out of range.\n",
__func__);
return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS,
"bad-txns-accumulated-fee-outofrange");
}
// The following checks do not apply to the coinbase.
if (isCoinBase) {
continue;
}
// Check that transaction is BIP68 final BIP68 lock checks (as
// opposed to nLockTime checks) must be in ConnectBlock because they
// require the UTXO set.
prevheights.resize(tx.vin.size());
for (size_t j = 0; j < tx.vin.size(); j++) {
prevheights[j] = view.AccessCoin(tx.vin[j].prevout).GetHeight();
}
if (!SequenceLocks(tx, nLockTimeFlags, prevheights, *pindex)) {
LogPrintf("ERROR: %s: contains a non-BIP68-final transaction\n",
__func__);
return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS,
"bad-txns-nonfinal");
}
// Don't cache results if we're actually connecting blocks (still
// consult the cache, though).
bool fCacheResults = fJustCheck;
const bool fEnforceSigCheck = flags & SCRIPT_ENFORCE_SIGCHECKS;
if (!fEnforceSigCheck) {
// Historically, there has been transactions with a very high
// sigcheck count, so we need to disable this check for such
// transactions.
nSigChecksTxLimiters[txIndex] = TxSigCheckLimiter::getDisabled();
}
std::vector<CScriptCheck> vChecks;
TxValidationState tx_state;
if (fScriptChecks &&
!CheckInputScripts(tx, tx_state, view, flags, fCacheResults,
fCacheResults, PrecomputedTransactionData(tx),
nSigChecksRet, nSigChecksTxLimiters[txIndex],
&nSigChecksBlockLimiter, &vChecks)) {
// Any transaction validation failure in ConnectBlock is a block
// consensus failure
state.Invalid(BlockValidationResult::BLOCK_CONSENSUS,
tx_state.GetRejectReason(),
tx_state.GetDebugMessage());
return error(
"ConnectBlock(): CheckInputScripts on %s failed with %s",
tx.GetId().ToString(), state.ToString());
}
control.Add(std::move(vChecks));
// Note: this must execute in the same iteration as CheckTxInputs (not
// in a separate loop) in order to detect double spends. However,
// this does not prevent double-spending by duplicated transaction
// inputs in the same transaction (cf. CVE-2018-17144) -- that check is
// done in CheckBlock (CheckRegularTransaction).
SpendCoins(view, tx, blockundo.vtxundo.at(txIndex), pindex->nHeight);
txIndex++;
}
int64_t nTime3 = GetTimeMicros();
nTimeConnect += nTime3 - nTime2;
LogPrint(BCLog::BENCH,
" - Connect %u transactions: %.2fms (%.3fms/tx, %.3fms/txin) "
"[%.2fs (%.2fms/blk)]\n",
(unsigned)block.vtx.size(), MILLI * (nTime3 - nTime2),
MILLI * (nTime3 - nTime2) / block.vtx.size(),
nInputs <= 1 ? 0 : MILLI * (nTime3 - nTime2) / (nInputs - 1),
nTimeConnect * MICRO, nTimeConnect * MILLI / nBlocksTotal);
const Amount blockReward =
nFees + GetBlockSubsidy(pindex->nHeight, consensusParams);
if (block.vtx[0]->GetValueOut() > blockReward) {
LogPrintf("ERROR: ConnectBlock(): coinbase pays too much (actual=%d vs "
"limit=%d)\n",
block.vtx[0]->GetValueOut(), blockReward);
return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS,
"bad-cb-amount");
}
if (blockFees) {
*blockFees = nFees;
}
if (!control.Wait()) {
return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS,
"blk-bad-inputs", "parallel script check failed");
}
int64_t nTime4 = GetTimeMicros();
nTimeVerify += nTime4 - nTime2;
LogPrint(
BCLog::BENCH,
" - Verify %u txins: %.2fms (%.3fms/txin) [%.2fs (%.2fms/blk)]\n",
nInputs - 1, MILLI * (nTime4 - nTime2),
nInputs <= 1 ? 0 : MILLI * (nTime4 - nTime2) / (nInputs - 1),
nTimeVerify * MICRO, nTimeVerify * MILLI / nBlocksTotal);
if (fJustCheck) {
return true;
}
if (!m_blockman.WriteUndoDataForBlock(blockundo, state, *pindex)) {
return false;
}
if (!pindex->IsValid(BlockValidity::SCRIPTS)) {
pindex->RaiseValidity(BlockValidity::SCRIPTS);
m_blockman.m_dirty_blockindex.insert(pindex);
}
// add this block to the view's block chain
view.SetBestBlock(pindex->GetBlockHash());
int64_t nTime5 = GetTimeMicros();
nTimeIndex += nTime5 - nTime4;
LogPrint(BCLog::BENCH, " - Index writing: %.2fms [%.2fs (%.2fms/blk)]\n",
MILLI * (nTime5 - nTime4), nTimeIndex * MICRO,
nTimeIndex * MILLI / nBlocksTotal);
TRACE6(validation, block_connected, block_hash.data(), pindex->nHeight,
block.vtx.size(), nInputs, nSigChecksRet,
// in microseconds (µs)
nTime5 - nTimeStart);
return true;
}
CoinsCacheSizeState Chainstate::GetCoinsCacheSizeState() {
AssertLockHeld(::cs_main);
return this->GetCoinsCacheSizeState(m_coinstip_cache_size_bytes,
m_mempool ? m_mempool->m_max_size_bytes
: 0);
}
CoinsCacheSizeState
Chainstate::GetCoinsCacheSizeState(size_t max_coins_cache_size_bytes,
size_t max_mempool_size_bytes) {
AssertLockHeld(::cs_main);
int64_t nMempoolUsage = m_mempool ? m_mempool->DynamicMemoryUsage() : 0;
int64_t cacheSize = CoinsTip().DynamicMemoryUsage();
int64_t nTotalSpace =
max_coins_cache_size_bytes +
std::max<int64_t>(int64_t(max_mempool_size_bytes) - nMempoolUsage, 0);
//! No need to periodic flush if at least this much space still available.
static constexpr int64_t MAX_BLOCK_COINSDB_USAGE_BYTES =
10 * 1024 * 1024; // 10MB
int64_t large_threshold = std::max(
(9 * nTotalSpace) / 10, nTotalSpace - MAX_BLOCK_COINSDB_USAGE_BYTES);
if (cacheSize > nTotalSpace) {
LogPrintf("Cache size (%s) exceeds total space (%s)\n", cacheSize,
nTotalSpace);
return CoinsCacheSizeState::CRITICAL;
} else if (cacheSize > large_threshold) {
return CoinsCacheSizeState::LARGE;
}
return CoinsCacheSizeState::OK;
}
bool Chainstate::FlushStateToDisk(BlockValidationState &state,
FlushStateMode mode, int nManualPruneHeight) {
LOCK(cs_main);
assert(this->CanFlushToDisk());
std::set<int> setFilesToPrune;
bool full_flush_completed = false;
const size_t coins_count = CoinsTip().GetCacheSize();
const size_t coins_mem_usage = CoinsTip().DynamicMemoryUsage();
try {
{
bool fFlushForPrune = false;
bool fDoFullFlush = false;
CoinsCacheSizeState cache_state = GetCoinsCacheSizeState();
LOCK(m_blockman.cs_LastBlockFile);
if (m_blockman.IsPruneMode() &&
(m_blockman.m_check_for_pruning || nManualPruneHeight > 0) &&
!fReindex) {
// Make sure we don't prune any of the prune locks bestblocks.
// Pruning is height-based.
int last_prune{m_chain.Height()};
// prune lock that actually was the limiting factor, only used
// for logging
std::optional<std::string> limiting_lock;
for (const auto &prune_lock : m_blockman.m_prune_locks) {
if (prune_lock.second.height_first ==
std::numeric_limits<int>::max()) {
continue;
}
// Remove the buffer and one additional block here to get
// actual height that is outside of the buffer
const int lock_height{prune_lock.second.height_first -
PRUNE_LOCK_BUFFER - 1};
last_prune = std::max(1, std::min(last_prune, lock_height));
if (last_prune == lock_height) {
limiting_lock = prune_lock.first;
}
}
if (limiting_lock) {
LogPrint(BCLog::PRUNE, "%s limited pruning to height %d\n",
limiting_lock.value(), last_prune);
}
if (nManualPruneHeight > 0) {
LOG_TIME_MILLIS_WITH_CATEGORY(
"find files to prune (manual)", BCLog::BENCH);
m_blockman.FindFilesToPruneManual(
setFilesToPrune,
std::min(last_prune, nManualPruneHeight),
m_chain.Height());
} else {
LOG_TIME_MILLIS_WITH_CATEGORY("find files to prune",
BCLog::BENCH);
m_blockman.FindFilesToPrune(
setFilesToPrune,
m_chainman.GetParams().PruneAfterHeight(),
m_chain.Height(), last_prune, IsInitialBlockDownload());
m_blockman.m_check_for_pruning = false;
}
if (!setFilesToPrune.empty()) {
fFlushForPrune = true;
if (!m_blockman.m_have_pruned) {
m_blockman.m_block_tree_db->WriteFlag(
"prunedblockfiles", true);
m_blockman.m_have_pruned = true;
}
}
}
const auto nNow = GetTime<std::chrono::microseconds>();
// Avoid writing/flushing immediately after startup.
if (m_last_write.count() == 0) {
m_last_write = nNow;
}
if (m_last_flush.count() == 0) {
m_last_flush = nNow;
}
// The cache is large and we're within 10% and 10 MiB of the limit,
// but we have time now (not in the middle of a block processing).
bool fCacheLarge = mode == FlushStateMode::PERIODIC &&
cache_state >= CoinsCacheSizeState::LARGE;
// The cache is over the limit, we have to write now.
bool fCacheCritical = mode == FlushStateMode::IF_NEEDED &&
cache_state >= CoinsCacheSizeState::CRITICAL;
// It's been a while since we wrote the block index to disk. Do this
// frequently, so we don't need to redownload after a crash.
bool fPeriodicWrite = mode == FlushStateMode::PERIODIC &&
nNow > m_last_write + DATABASE_WRITE_INTERVAL;
// It's been very long since we flushed the cache. Do this
// infrequently, to optimize cache usage.
bool fPeriodicFlush = mode == FlushStateMode::PERIODIC &&
nNow > m_last_flush + DATABASE_FLUSH_INTERVAL;
// Combine all conditions that result in a full cache flush.
fDoFullFlush = (mode == FlushStateMode::ALWAYS) || fCacheLarge ||
fCacheCritical || fPeriodicFlush || fFlushForPrune;
// Write blocks and block index to disk.
if (fDoFullFlush || fPeriodicWrite) {
// Ensure we can write block index
if (!CheckDiskSpace(gArgs.GetBlocksDirPath())) {
return AbortNode(state, "Disk space is too low!",
_("Disk space is too low!"));
}
{
LOG_TIME_MILLIS_WITH_CATEGORY(
"write block and undo data to disk", BCLog::BENCH);
// First make sure all block and undo data is flushed to
// disk.
m_blockman.FlushBlockFile();
}
// Then update all block file information (which may refer to
// block and undo files).
{
LOG_TIME_MILLIS_WITH_CATEGORY("write block index to disk",
BCLog::BENCH);
if (!m_blockman.WriteBlockIndexDB()) {
return AbortNode(
state, "Failed to write to block index database");
}
}
// Finally remove any pruned files
if (fFlushForPrune) {
LOG_TIME_MILLIS_WITH_CATEGORY("unlink pruned files",
BCLog::BENCH);
m_blockman.UnlinkPrunedFiles(setFilesToPrune);
}
m_last_write = nNow;
}
// Flush best chain related state. This can only be done if the
// blocks / block index write was also done.
if (fDoFullFlush && !CoinsTip().GetBestBlock().IsNull()) {
LOG_TIME_MILLIS_WITH_CATEGORY(
strprintf("write coins cache to disk (%d coins, %.2fkB)",
coins_count, coins_mem_usage / 1000),
BCLog::BENCH);
// Typical Coin structures on disk are around 48 bytes in size.
// Pushing a new one to the database can cause it to be written
// twice (once in the log, and once in the tables). This is
// already an overestimation, as most will delete an existing
// entry or overwrite one. Still, use a conservative safety
// factor of 2.
if (!CheckDiskSpace(gArgs.GetDataDirNet(),
48 * 2 * 2 * CoinsTip().GetCacheSize())) {
return AbortNode(state, "Disk space is too low!",
_("Disk space is too low!"));
}
// Flush the chainstate (which may refer to block index
// entries).
if (!CoinsTip().Flush()) {
return AbortNode(state, "Failed to write to coin database");
}
m_last_flush = nNow;
full_flush_completed = true;
}
TRACE5(utxocache, flush,
// in microseconds (µs)
GetTimeMicros() - nNow.count(), uint32_t(mode), coins_count,
uint64_t(coins_mem_usage), fFlushForPrune);
}
if (full_flush_completed) {
// Update best block in wallet (so we can detect restored wallets).
GetMainSignals().ChainStateFlushed(m_chain.GetLocator());
}
} catch (const std::runtime_error &e) {
return AbortNode(state, std::string("System error while flushing: ") +
e.what());
}
return true;
}
void Chainstate::ForceFlushStateToDisk() {
BlockValidationState state;
if (!this->FlushStateToDisk(state, FlushStateMode::ALWAYS)) {
LogPrintf("%s: failed to flush state (%s)\n", __func__,
state.ToString());
}
}
void Chainstate::PruneAndFlush() {
BlockValidationState state;
m_blockman.m_check_for_pruning = true;
if (!this->FlushStateToDisk(state, FlushStateMode::NONE)) {
LogPrintf("%s: failed to flush state (%s)\n", __func__,
state.ToString());
}
}
static void UpdateTipLog(const CCoinsViewCache &coins_tip,
const CBlockIndex *tip, const CChainParams ¶ms,
const std::string &func_name,
const std::string &prefix)
EXCLUSIVE_LOCKS_REQUIRED(::cs_main) {
AssertLockHeld(::cs_main);
LogPrintf("%s%s: new best=%s height=%d version=0x%08x log2_work=%f tx=%ld "
"date='%s' progress=%f cache=%.1fMiB(%utxo)\n",
prefix, func_name, tip->GetBlockHash().ToString(), tip->nHeight,
tip->nVersion, log(tip->nChainWork.getdouble()) / log(2.0),
tip->GetChainTxCount(),
FormatISO8601DateTime(tip->GetBlockTime()),
GuessVerificationProgress(params.TxData(), tip),
coins_tip.DynamicMemoryUsage() * (1.0 / (1 << 20)),
coins_tip.GetCacheSize());
}
void Chainstate::UpdateTip(const CBlockIndex *pindexNew) {
AssertLockHeld(::cs_main);
const auto &coins_tip = CoinsTip();
const CChainParams ¶ms{m_chainman.GetParams()};
// The remainder of the function isn't relevant if we are not acting on
// the active chainstate, so return if need be.
if (this != &m_chainman.ActiveChainstate()) {
// Only log every so often so that we don't bury log messages at the
// tip.
constexpr int BACKGROUND_LOG_INTERVAL = 2000;
if (pindexNew->nHeight % BACKGROUND_LOG_INTERVAL == 0) {
UpdateTipLog(coins_tip, pindexNew, params, __func__,
"[background validation] ");
}
return;
}
// New best block
if (m_mempool) {
m_mempool->AddTransactionsUpdated(1);
}
{
LOCK(g_best_block_mutex);
g_best_block = pindexNew->GetBlockHash();
g_best_block_cv.notify_all();
}
UpdateTipLog(coins_tip, pindexNew, params, __func__, "");
}
/**
* Disconnect m_chain's tip.
* After calling, the mempool will be in an inconsistent state, with
* transactions from disconnected blocks being added to disconnectpool. You
* should make the mempool consistent again by calling updateMempoolForReorg.
* with cs_main held.
*
* If disconnectpool is nullptr, then no disconnected transactions are added to
* disconnectpool (note that the caller is responsible for mempool consistency
* in any case).
*/
bool Chainstate::DisconnectTip(BlockValidationState &state,
DisconnectedBlockTransactions *disconnectpool) {
AssertLockHeld(cs_main);
if (m_mempool) {
AssertLockHeld(m_mempool->cs);
}
CBlockIndex *pindexDelete = m_chain.Tip();
assert(pindexDelete);
assert(pindexDelete->pprev);
// Read block from disk.
std::shared_ptr<CBlock> pblock = std::make_shared<CBlock>();
CBlock &block = *pblock;
if (!m_blockman.ReadBlockFromDisk(block, *pindexDelete)) {
return error("DisconnectTip(): Failed to read block");
}
// Apply the block atomically to the chain state.
int64_t nStart = GetTimeMicros();
{
CCoinsViewCache view(&CoinsTip());
assert(view.GetBestBlock() == pindexDelete->GetBlockHash());
if (DisconnectBlock(block, pindexDelete, view) !=
DisconnectResult::OK) {
return error("DisconnectTip(): DisconnectBlock %s failed",
pindexDelete->GetBlockHash().ToString());
}
bool flushed = view.Flush();
assert(flushed);
}
LogPrint(BCLog::BENCH, "- Disconnect block: %.2fms\n",
(GetTimeMicros() - nStart) * MILLI);
{
// Prune locks that began at or after the tip should be moved backward
// so they get a chance to reorg
const int max_height_first{pindexDelete->nHeight - 1};
for (auto &prune_lock : m_blockman.m_prune_locks) {
if (prune_lock.second.height_first <= max_height_first) {
continue;
}
prune_lock.second.height_first = max_height_first;
LogPrint(BCLog::PRUNE, "%s prune lock moved back to %d\n",
prune_lock.first, max_height_first);
}
}
// Write the chain state to disk, if necessary.
if (!FlushStateToDisk(state, FlushStateMode::IF_NEEDED)) {
return false;
}
if (m_mempool) {
// If this block is deactivating a fork, we move all mempool
// transactions in front of disconnectpool for reprocessing in a future
// updateMempoolForReorg call
if (pindexDelete->pprev != nullptr &&
GetNextBlockScriptFlags(pindexDelete, m_chainman) !=
GetNextBlockScriptFlags(pindexDelete->pprev, m_chainman)) {
LogPrint(BCLog::MEMPOOL,
"Disconnecting mempool due to rewind of upgrade block\n");
if (disconnectpool) {
disconnectpool->importMempool(*m_mempool);
}
m_mempool->clear();
}
if (disconnectpool) {
disconnectpool->addForBlock(block.vtx, *m_mempool);
}
}
m_chain.SetTip(*pindexDelete->pprev);
UpdateTip(pindexDelete->pprev);
// Let wallets know transactions went from 1-confirmed to
// 0-confirmed or conflicted:
GetMainSignals().BlockDisconnected(pblock, pindexDelete);
return true;
}
static int64_t nTimeReadFromDisk = 0;
static int64_t nTimeConnectTotal = 0;
static int64_t nTimeFlush = 0;
static int64_t nTimeChainState = 0;
static int64_t nTimePostConnect = 0;
struct PerBlockConnectTrace {
CBlockIndex *pindex = nullptr;
std::shared_ptr<const CBlock> pblock;
PerBlockConnectTrace() {}
};
/**
* Used to track blocks whose transactions were applied to the UTXO state as a
* part of a single ActivateBestChainStep call.
*
* This class is single-use, once you call GetBlocksConnected() you have to
* throw it away and make a new one.
*/
class ConnectTrace {
private:
std::vector<PerBlockConnectTrace> blocksConnected;
public:
explicit ConnectTrace() : blocksConnected(1) {}
void BlockConnected(CBlockIndex *pindex,
std::shared_ptr<const CBlock> pblock) {
assert(!blocksConnected.back().pindex);
assert(pindex);
assert(pblock);
blocksConnected.back().pindex = pindex;
blocksConnected.back().pblock = std::move(pblock);
blocksConnected.emplace_back();
}
std::vector<PerBlockConnectTrace> &GetBlocksConnected() {
// We always keep one extra block at the end of our list because blocks
// are added after all the conflicted transactions have been filled in.
// Thus, the last entry should always be an empty one waiting for the
// transactions from the next block. We pop the last entry here to make
// sure the list we return is sane.
assert(!blocksConnected.back().pindex);
blocksConnected.pop_back();
return blocksConnected;
}
};
/**
* Connect a new block to m_chain. pblock is either nullptr or a pointer to
* a CBlock corresponding to pindexNew, to bypass loading it again from disk.
*
* The block is added to connectTrace if connection succeeds.
*/
bool Chainstate::ConnectTip(BlockValidationState &state,
BlockPolicyValidationState &blockPolicyState,
CBlockIndex *pindexNew,
const std::shared_ptr<const CBlock> &pblock,
ConnectTrace &connectTrace,
DisconnectedBlockTransactions &disconnectpool,
const avalanche::Processor *const avalanche) {
AssertLockHeld(cs_main);
if (m_mempool) {
AssertLockHeld(m_mempool->cs);
}
const Consensus::Params &consensusParams = m_chainman.GetConsensus();
assert(pindexNew->pprev == m_chain.Tip());
// Read block from disk.
int64_t nTime1 = GetTimeMicros();
std::shared_ptr<const CBlock> pthisBlock;
if (!pblock) {
std::shared_ptr<CBlock> pblockNew = std::make_shared<CBlock>();
if (!m_blockman.ReadBlockFromDisk(*pblockNew, *pindexNew)) {
return AbortNode(state, "Failed to read block");
}
pthisBlock = pblockNew;
} else {
pthisBlock = pblock;
}
const CBlock &blockConnecting = *pthisBlock;
// Apply the block atomically to the chain state.
int64_t nTime2 = GetTimeMicros();
nTimeReadFromDisk += nTime2 - nTime1;
int64_t nTime3;
LogPrint(BCLog::BENCH, " - Load block from disk: %.2fms [%.2fs]\n",
(nTime2 - nTime1) * MILLI, nTimeReadFromDisk * MICRO);
{
Amount blockFees{Amount::zero()};
CCoinsViewCache view(&CoinsTip());
bool rv = ConnectBlock(blockConnecting, state, pindexNew, view,
BlockValidationOptions(m_chainman.GetConfig()),
&blockFees);
GetMainSignals().BlockChecked(blockConnecting, state);
if (!rv) {
if (state.IsInvalid()) {
InvalidBlockFound(pindexNew, state);
}
return error("%s: ConnectBlock %s failed, %s", __func__,
pindexNew->GetBlockHash().ToString(),
state.ToString());
}
/**
* The block is valid by consensus rules so now we check if the block
* passes all block policy checks. If not, then park the block and bail.
*
* We check block parking policies before flushing changes to the UTXO
* set. This allows us to avoid rewinding everything immediately after.
*
* Only check block parking policies the first time the block is
* connected. Avalanche voting can override the parking decision made by
* these policies.
*/
const BlockHash blockhash = pindexNew->GetBlockHash();
if (!IsInitialBlockDownload() &&
!m_filterParkingPoliciesApplied.contains(blockhash)) {
m_filterParkingPoliciesApplied.insert(blockhash);
const Amount blockReward =
blockFees +
GetBlockSubsidy(pindexNew->nHeight, consensusParams);
std::vector<std::unique_ptr<ParkingPolicy>> parkingPolicies;
parkingPolicies.emplace_back(std::make_unique<MinerFundPolicy>(
consensusParams, *pindexNew, blockConnecting, blockReward));
if (avalanche) {
parkingPolicies.emplace_back(
std::make_unique<StakingRewardsPolicy>(
*avalanche, consensusParams, *pindexNew,
blockConnecting, blockReward));
if (m_mempool) {
parkingPolicies.emplace_back(
std::make_unique<PreConsensusPolicy>(
*pindexNew, blockConnecting, m_mempool));
}
}
// If any block policy is violated, bail on the first one found
if (std::find_if_not(parkingPolicies.begin(), parkingPolicies.end(),
[&](const auto &policy) {
bool ret = (*policy)(blockPolicyState);
if (!ret) {
LogPrintf(
"Park block because it "
"violated a block policy: %s\n",
blockPolicyState.ToString());
}
return ret;
}) != parkingPolicies.end()) {
pindexNew->nStatus = pindexNew->nStatus.withParked();
m_blockman.m_dirty_blockindex.insert(pindexNew);
return false;
}
}
nTime3 = GetTimeMicros();
nTimeConnectTotal += nTime3 - nTime2;
assert(nBlocksTotal > 0);
LogPrint(BCLog::BENCH,
" - Connect total: %.2fms [%.2fs (%.2fms/blk)]\n",
(nTime3 - nTime2) * MILLI, nTimeConnectTotal * MICRO,
nTimeConnectTotal * MILLI / nBlocksTotal);
bool flushed = view.Flush();
assert(flushed);
}
int64_t nTime4 = GetTimeMicros();
nTimeFlush += nTime4 - nTime3;
LogPrint(BCLog::BENCH, " - Flush: %.2fms [%.2fs (%.2fms/blk)]\n",
(nTime4 - nTime3) * MILLI, nTimeFlush * MICRO,
nTimeFlush * MILLI / nBlocksTotal);
// Write the chain state to disk, if necessary.
if (!FlushStateToDisk(state, FlushStateMode::IF_NEEDED)) {
return false;
}
int64_t nTime5 = GetTimeMicros();
nTimeChainState += nTime5 - nTime4;
LogPrint(BCLog::BENCH,
" - Writing chainstate: %.2fms [%.2fs (%.2fms/blk)]\n",
(nTime5 - nTime4) * MILLI, nTimeChainState * MICRO,
nTimeChainState * MILLI / nBlocksTotal);
// Remove conflicting transactions from the mempool;
if (m_mempool) {
disconnectpool.removeForBlock(blockConnecting.vtx, *m_mempool);
// If this block is activating a fork, we move all mempool transactions
// in front of disconnectpool for reprocessing in a future
// updateMempoolForReorg call
if (pindexNew->pprev != nullptr &&
GetNextBlockScriptFlags(pindexNew, m_chainman) !=
GetNextBlockScriptFlags(pindexNew->pprev, m_chainman)) {
LogPrint(
BCLog::MEMPOOL,
"Disconnecting mempool due to acceptance of upgrade block\n");
disconnectpool.importMempool(*m_mempool);
}
}
// Update m_chain & related variables.
m_chain.SetTip(*pindexNew);
UpdateTip(pindexNew);
int64_t nTime6 = GetTimeMicros();
nTimePostConnect += nTime6 - nTime5;
nTimeTotal += nTime6 - nTime1;
LogPrint(BCLog::BENCH,
" - Connect postprocess: %.2fms [%.2fs (%.2fms/blk)]\n",
(nTime6 - nTime5) * MILLI, nTimePostConnect * MICRO,
nTimePostConnect * MILLI / nBlocksTotal);
LogPrint(BCLog::BENCH, "- Connect block: %.2fms [%.2fs (%.2fms/blk)]\n",
(nTime6 - nTime1) * MILLI, nTimeTotal * MICRO,
nTimeTotal * MILLI / nBlocksTotal);
// If we are the background validation chainstate, check to see if we are
// done validating the snapshot (i.e. our tip has reached the snapshot's
// base block).
if (this != &m_chainman.ActiveChainstate()) {
// This call may set `m_disabled`, which is referenced immediately
// afterwards in ActivateBestChain, so that we stop connecting blocks
// past the snapshot base.
m_chainman.MaybeCompleteSnapshotValidation();
}
connectTrace.BlockConnected(pindexNew, std::move(pthisBlock));
return true;
}
/**
* Return the tip of the chain with the most work in it, that isn't known to be
* invalid (it's however far from certain to be valid).
*/
CBlockIndex *Chainstate::FindMostWorkChain(
std::vector<const CBlockIndex *> &blocksToReconcile, bool fAutoUnpark) {
AssertLockHeld(::cs_main);
do {
CBlockIndex *pindexNew = nullptr;
// Find the best candidate header.
{
std::set<CBlockIndex *, CBlockIndexWorkComparator>::reverse_iterator
it = setBlockIndexCandidates.rbegin();
if (it == setBlockIndexCandidates.rend()) {
return nullptr;
}
pindexNew = *it;
}
// If this block will cause an avalanche finalized block to be reorged,
// then we park it.
{
LOCK(cs_avalancheFinalizedBlockIndex);
if (m_avalancheFinalizedBlockIndex &&
!AreOnTheSameFork(pindexNew, m_avalancheFinalizedBlockIndex)) {
LogPrintf("Park block %s because it forks prior to the "
"avalanche finalized chaintip.\n",
pindexNew->GetBlockHash().ToString());
pindexNew->nStatus = pindexNew->nStatus.withParked();
m_blockman.m_dirty_blockindex.insert(pindexNew);
}
}
const CBlockIndex *pindexFork = m_chain.FindFork(pindexNew);
// Check whether all blocks on the path between the currently active
// chain and the candidate are valid. Just going until the active chain
// is an optimization, as we know all blocks in it are valid already.
CBlockIndex *pindexTest = pindexNew;
bool hasValidAncestor = true;
while (hasValidAncestor && pindexTest && pindexTest != pindexFork) {
assert(pindexTest->HaveTxsDownloaded() || pindexTest->nHeight == 0);
// If this is a parked chain, but it has enough PoW, clear the park
// state.
bool fParkedChain = pindexTest->nStatus.isOnParkedChain();
if (fAutoUnpark && fParkedChain) {
const CBlockIndex *pindexTip = m_chain.Tip();
// During initialization, pindexTip and/or pindexFork may be
// null. In this case, we just ignore the fact that the chain is
// parked.
if (!pindexTip || !pindexFork) {
UnparkBlock(pindexTest);
continue;
}
// A parked chain can be unparked if it has twice as much PoW
// accumulated as the main chain has since the fork block.
CBlockIndex const *pindexExtraPow = pindexTip;
arith_uint256 requiredWork = pindexTip->nChainWork;
switch (pindexTip->nHeight - pindexFork->nHeight) {
// Limit the penality for depth 1, 2 and 3 to half a block
// worth of work to ensure we don't fork accidentally.
case 3:
case 2:
pindexExtraPow = pindexExtraPow->pprev;
// FALLTHROUGH
case 1: {
const arith_uint256 deltaWork =
pindexExtraPow->nChainWork - pindexFork->nChainWork;
requiredWork += (deltaWork >> 1);
break;
}
default:
requiredWork +=
pindexExtraPow->nChainWork - pindexFork->nChainWork;
break;
}
if (pindexNew->nChainWork > requiredWork) {
// We have enough, clear the parked state.
LogPrintf("Unpark chain up to block %s as it has "
"accumulated enough PoW.\n",
pindexNew->GetBlockHash().ToString());
fParkedChain = false;
UnparkBlock(pindexTest);
}
}
// Pruned nodes may have entries in setBlockIndexCandidates for
// which block files have been deleted. Remove those as candidates
// for the most work chain if we come across them; we can't switch
// to a chain unless we have all the non-active-chain parent blocks.
bool fInvalidChain = pindexTest->nStatus.isInvalid();
bool fMissingData = !pindexTest->nStatus.hasData();
if (!(fInvalidChain || fParkedChain || fMissingData)) {
// The current block is acceptable, move to the parent, up to
// the fork point.
pindexTest = pindexTest->pprev;
continue;
}
// Candidate chain is not usable (either invalid or parked or
// missing data)
hasValidAncestor = false;
setBlockIndexCandidates.erase(pindexTest);
if (fInvalidChain && (m_chainman.m_best_invalid == nullptr ||
pindexNew->nChainWork >
m_chainman.m_best_invalid->nChainWork)) {
m_chainman.m_best_invalid = pindexNew;
}
if (fParkedChain && (m_chainman.m_best_parked == nullptr ||
pindexNew->nChainWork >
m_chainman.m_best_parked->nChainWork)) {
m_chainman.m_best_parked = pindexNew;
}
LogPrintf("Considered switching to better tip %s but that chain "
"contains a%s%s%s block.\n",
pindexNew->GetBlockHash().ToString(),
fInvalidChain ? "n invalid" : "",
fParkedChain ? " parked" : "",
fMissingData ? " missing-data" : "");
CBlockIndex *pindexFailed = pindexNew;
// Remove the entire chain from the set.
while (pindexTest != pindexFailed) {
if (fInvalidChain || fParkedChain) {
pindexFailed->nStatus =
pindexFailed->nStatus.withFailedParent(fInvalidChain)
.withParkedParent(fParkedChain);
} else if (fMissingData) {
// If we're missing data, then add back to
// m_blocks_unlinked, so that if the block arrives in the
// future we can try adding to setBlockIndexCandidates
// again.
m_blockman.m_blocks_unlinked.insert(
std::make_pair(pindexFailed->pprev, pindexFailed));
}
setBlockIndexCandidates.erase(pindexFailed);
pindexFailed = pindexFailed->pprev;
}
if (fInvalidChain || fParkedChain) {
// We discovered a new chain tip that is either parked or
// invalid, we may want to warn.
CheckForkWarningConditionsOnNewFork(pindexNew);
}
}
blocksToReconcile.push_back(pindexNew);
// We found a candidate that has valid ancestors. This is our guy.
if (hasValidAncestor) {
return pindexNew;
}
} while (true);
}
/**
* Delete all entries in setBlockIndexCandidates that are worse than the current
* tip.
*/
void Chainstate::PruneBlockIndexCandidates() {
// Note that we can't delete the current block itself, as we may need to
// return to it later in case a reorganization to a better block fails.
auto it = setBlockIndexCandidates.begin();
while (it != setBlockIndexCandidates.end() &&
setBlockIndexCandidates.value_comp()(*it, m_chain.Tip())) {
setBlockIndexCandidates.erase(it++);
}
// Either the current tip or a successor of it we're working towards is left
// in setBlockIndexCandidates.
assert(!setBlockIndexCandidates.empty());
}
/**
* Try to make some progress towards making pindexMostWork the active block.
* pblock is either nullptr or a pointer to a CBlock corresponding to
* pindexMostWork.
*
* @returns true unless a system error occurred
*/
bool Chainstate::ActivateBestChainStep(
BlockValidationState &state, CBlockIndex *pindexMostWork,
const std::shared_ptr<const CBlock> &pblock, bool &fInvalidFound,
ConnectTrace &connectTrace, const avalanche::Processor *const avalanche) {
AssertLockHeld(cs_main);
if (m_mempool) {
AssertLockHeld(m_mempool->cs);
}
const CBlockIndex *pindexOldTip = m_chain.Tip();
const CBlockIndex *pindexFork = m_chain.FindFork(pindexMostWork);
// Disconnect active blocks which are no longer in the best chain.
bool fBlocksDisconnected = false;
DisconnectedBlockTransactions disconnectpool;
while (m_chain.Tip() && m_chain.Tip() != pindexFork) {
if (!fBlocksDisconnected) {
// Import and clear mempool; we must do this to preserve
// topological ordering in the mempool index. This is ok since
// inserts into the mempool are very fast now in our new
// implementation.
disconnectpool.importMempool(*m_mempool);
}
if (!DisconnectTip(state, &disconnectpool)) {
// This is likely a fatal error, but keep the mempool consistent,
// just in case. Only remove from the mempool in this case.
if (m_mempool) {
disconnectpool.updateMempoolForReorg(*this, false, *m_mempool);
}
// If we're unable to disconnect a block during normal operation,
// then that is a failure of our local system -- we should abort
// rather than stay on a less work chain.
AbortNode(state,
"Failed to disconnect block; see debug.log for details");
return false;
}
fBlocksDisconnected = true;
}
// Build list of new blocks to connect.
std::vector<CBlockIndex *> vpindexToConnect;
bool fContinue = true;
int nHeight = pindexFork ? pindexFork->nHeight : -1;
while (fContinue && nHeight != pindexMostWork->nHeight) {
// Don't iterate the entire list of potential improvements toward the
// best tip, as we likely only need a few blocks along the way.
int nTargetHeight = std::min(nHeight + 32, pindexMostWork->nHeight);
vpindexToConnect.clear();
vpindexToConnect.reserve(nTargetHeight - nHeight);
CBlockIndex *pindexIter = pindexMostWork->GetAncestor(nTargetHeight);
while (pindexIter && pindexIter->nHeight != nHeight) {
vpindexToConnect.push_back(pindexIter);
pindexIter = pindexIter->pprev;
}
nHeight = nTargetHeight;
// Connect new blocks.
for (CBlockIndex *pindexConnect : reverse_iterate(vpindexToConnect)) {
BlockPolicyValidationState blockPolicyState;
if (!ConnectTip(state, blockPolicyState, pindexConnect,
pindexConnect == pindexMostWork
? pblock
: std::shared_ptr<const CBlock>(),
connectTrace, disconnectpool, avalanche)) {
if (state.IsInvalid()) {
// The block violates a consensus rule.
if (state.GetResult() !=
BlockValidationResult::BLOCK_MUTATED) {
InvalidChainFound(vpindexToConnect.back());
}
state = BlockValidationState();
fInvalidFound = true;
fContinue = false;
break;
}
if (blockPolicyState.IsInvalid()) {
// The block violates a policy rule.
fContinue = false;
break;
}
// A system error occurred (disk space, database error, ...).
// Make the mempool consistent with the current tip, just in
// case any observers try to use it before shutdown.
if (m_mempool) {
disconnectpool.updateMempoolForReorg(*this, false,
*m_mempool);
}
return false;
} else {
PruneBlockIndexCandidates();
if (!pindexOldTip ||
m_chain.Tip()->nChainWork > pindexOldTip->nChainWork) {
// We're in a better position than we were. Return
// temporarily to release the lock.
fContinue = false;
break;
}
}
}
}
if (m_mempool) {
if (fBlocksDisconnected || !disconnectpool.isEmpty()) {
// If any blocks were disconnected, we need to update the mempool
// even if disconnectpool is empty. The disconnectpool may also be
// non-empty if the mempool was imported due to new validation rules
// being in effect.
LogPrint(BCLog::MEMPOOL,
"Updating mempool due to reorganization or "
"rules upgrade/downgrade\n");
disconnectpool.updateMempoolForReorg(*this, true, *m_mempool);
}
m_mempool->check(this->CoinsTip(), this->m_chain.Height() + 1);
}
// Callbacks/notifications for a new best chain.
if (fInvalidFound) {
CheckForkWarningConditionsOnNewFork(pindexMostWork);
} else {
CheckForkWarningConditions();
}
return true;
}
static SynchronizationState GetSynchronizationState(bool init) {
if (!init) {
return SynchronizationState::POST_INIT;
}
if (::fReindex) {
return SynchronizationState::INIT_REINDEX;
}
return SynchronizationState::INIT_DOWNLOAD;
}
static bool NotifyHeaderTip(Chainstate &chainstate) LOCKS_EXCLUDED(cs_main) {
bool fNotify = false;
bool fInitialBlockDownload = false;
static CBlockIndex *pindexHeaderOld = nullptr;
CBlockIndex *pindexHeader = nullptr;
{
LOCK(cs_main);
pindexHeader = chainstate.m_chainman.m_best_header;
if (pindexHeader != pindexHeaderOld) {
fNotify = true;
fInitialBlockDownload = chainstate.IsInitialBlockDownload();
pindexHeaderOld = pindexHeader;
}
}
// Send block tip changed notifications without cs_main
if (fNotify) {
chainstate.m_chainman.GetNotifications().headerTip(
GetSynchronizationState(fInitialBlockDownload),
pindexHeader->nHeight, pindexHeader->nTime, false);
}
return fNotify;
}
static void LimitValidationInterfaceQueue() LOCKS_EXCLUDED(cs_main) {
AssertLockNotHeld(cs_main);
if (GetMainSignals().CallbacksPending() > 10) {
SyncWithValidationInterfaceQueue();
}
}
bool Chainstate::ActivateBestChain(BlockValidationState &state,
std::shared_ptr<const CBlock> pblock,
avalanche::Processor *const avalanche,
bool skip_checkblockindex) {
AssertLockNotHeld(m_chainstate_mutex);
// Note that while we're often called here from ProcessNewBlock, this is
// far from a guarantee. Things in the P2P/RPC will often end up calling
// us in the middle of ProcessNewBlock - do not assume pblock is set
// sanely for performance or correctness!
AssertLockNotHeld(::cs_main);
// ABC maintains a fair degree of expensive-to-calculate internal state
// because this function periodically releases cs_main so that it does not
// lock up other threads for too long during large connects - and to allow
// for e.g. the callback queue to drain we use m_chainstate_mutex to enforce
// mutual exclusion so that only one caller may execute this function at a
// time
LOCK(m_chainstate_mutex);
// Belt-and-suspenders check that we aren't attempting to advance the
// background chainstate past the snapshot base block.
if (WITH_LOCK(::cs_main, return m_disabled)) {
LogPrintf("m_disabled is set - this chainstate should not be in "
"operation. Please report this as a bug. %s\n",
PACKAGE_BUGREPORT);
return false;
}
CBlockIndex *pindexMostWork = nullptr;
CBlockIndex *pindexNewTip = nullptr;
int nStopAtHeight = gArgs.GetIntArg("-stopatheight", DEFAULT_STOPATHEIGHT);
do {
// Block until the validation queue drains. This should largely
// never happen in normal operation, however may happen during
// reindex, causing memory blowup if we run too far ahead.
// Note that if a validationinterface callback ends up calling
// ActivateBestChain this may lead to a deadlock! We should
// probably have a DEBUG_LOCKORDER test for this in the future.
LimitValidationInterfaceQueue();
std::vector<const CBlockIndex *> blocksToReconcile;
bool blocks_connected = false;
const bool fAutoUnpark =
gArgs.GetBoolArg("-automaticunparking", !avalanche);
{
LOCK(cs_main);
// Lock transaction pool for at least as long as it takes for
// connectTrace to be consumed
LOCK(MempoolMutex());
CBlockIndex *starting_tip = m_chain.Tip();
do {
// We absolutely may not unlock cs_main until we've made forward
// progress (with the exception of shutdown due to hardware
// issues, low disk space, etc).
// Destructed before cs_main is unlocked
ConnectTrace connectTrace;
if (pindexMostWork == nullptr) {
pindexMostWork =
FindMostWorkChain(blocksToReconcile, fAutoUnpark);
}
// Whether we have anything to do at all.
if (pindexMostWork == nullptr ||
pindexMostWork == m_chain.Tip()) {
break;
}
bool fInvalidFound = false;
std::shared_ptr<const CBlock> nullBlockPtr;
if (!ActivateBestChainStep(
state, pindexMostWork,
pblock && pblock->GetHash() ==
pindexMostWork->GetBlockHash()
? pblock
: nullBlockPtr,
fInvalidFound, connectTrace, avalanche)) {
// A system error occurred
return false;
}
blocks_connected = true;
if (fInvalidFound ||
(pindexMostWork && pindexMostWork->nStatus.isParked())) {
// Wipe cache, we may need another branch now.
pindexMostWork = nullptr;
}
pindexNewTip = m_chain.Tip();
for (const PerBlockConnectTrace &trace :
connectTrace.GetBlocksConnected()) {
assert(trace.pblock && trace.pindex);
GetMainSignals().BlockConnected(trace.pblock, trace.pindex);
}
// This will have been toggled in
// ActivateBestChainStep -> ConnectTip ->
// MaybeCompleteSnapshotValidation, if at all, so we should
// catch it here.
//
// Break this do-while to ensure we don't advance past the base
// snapshot.
if (m_disabled) {
break;
}
} while (!m_chain.Tip() ||
(starting_tip && CBlockIndexWorkComparator()(
m_chain.Tip(), starting_tip)));
// Check the index once we're done with the above loop, since
// we're going to release cs_main soon. If the index is in a bad
// state now, then it's better to know immediately rather than
// randomly have it cause a problem in a race.
if (!skip_checkblockindex) {
CheckBlockIndex();
}
if (blocks_connected) {
const CBlockIndex *pindexFork = m_chain.FindFork(starting_tip);
bool fInitialDownload = IsInitialBlockDownload();
// Notify external listeners about the new tip.
// Enqueue while holding cs_main to ensure that UpdatedBlockTip
// is called in the order in which blocks are connected
if (pindexFork != pindexNewTip) {
// Notify ValidationInterface subscribers
GetMainSignals().UpdatedBlockTip(pindexNewTip, pindexFork,
fInitialDownload);
// Always notify the UI if a new block tip was connected
m_chainman.GetNotifications().blockTip(
GetSynchronizationState(fInitialDownload),
*pindexNewTip);
}
}
}
// When we reach this point, we switched to a new tip (stored in
// pindexNewTip).
if (avalanche) {
for (const CBlockIndex *pindex : blocksToReconcile) {
avalanche->addToReconcile(pindex);
avalanche->computeStakingReward(pindex);
}
}
if (!blocks_connected) {
return true;
}
if (nStopAtHeight && pindexNewTip &&
pindexNewTip->nHeight >= nStopAtHeight) {
StartShutdown();
}
if (WITH_LOCK(::cs_main, return m_disabled)) {
// Background chainstate has reached the snapshot base block, so
// exit.
break;
}
// We check shutdown only after giving ActivateBestChainStep a chance to
// run once so that we never shutdown before connecting the genesis
// block during LoadChainTip(). Previously this caused an assert()
// failure during shutdown in such cases as the UTXO DB flushing checks
// that the best block hash is non-null.
if (ShutdownRequested()) {
break;
}
} while (pindexNewTip != pindexMostWork);
// Write changes periodically to disk, after relay.
if (!FlushStateToDisk(state, FlushStateMode::PERIODIC)) {
return false;
}
return true;
}
bool Chainstate::PreciousBlock(BlockValidationState &state, CBlockIndex *pindex,
avalanche::Processor *const avalanche) {
AssertLockNotHeld(m_chainstate_mutex);
AssertLockNotHeld(::cs_main);
{
LOCK(cs_main);
if (pindex->nChainWork < m_chain.Tip()->nChainWork) {
// Nothing to do, this block is not at the tip.
return true;
}
if (m_chain.Tip()->nChainWork > nLastPreciousChainwork) {
// The chain has been extended since the last call, reset the
// counter.
nBlockReverseSequenceId = -1;
}
nLastPreciousChainwork = m_chain.Tip()->nChainWork;
setBlockIndexCandidates.erase(pindex);
pindex->nSequenceId = nBlockReverseSequenceId;
if (nBlockReverseSequenceId > std::numeric_limits<int32_t>::min()) {
// We can't keep reducing the counter if somebody really wants to
// call preciousblock 2**31-1 times on the same set of tips...
nBlockReverseSequenceId--;
}
// In case this was parked, unpark it.
UnparkBlock(pindex);
// Make sure it is added to the candidate list if appropriate.
if (pindex->IsValid(BlockValidity::TRANSACTIONS) &&
pindex->HaveTxsDownloaded()) {
setBlockIndexCandidates.insert(pindex);
PruneBlockIndexCandidates();
}
}
return ActivateBestChain(state, /*pblock=*/nullptr, avalanche);
}
namespace {
// Leverage RAII to run a functor at scope end
template <typename Func> struct Defer {
Func func;
Defer(Func &&f) : func(std::move(f)) {}
~Defer() { func(); }
};
} // namespace
bool Chainstate::UnwindBlock(BlockValidationState &state, CBlockIndex *pindex,
bool invalidate) {
// Genesis block can't be invalidated or parked
assert(pindex);
if (pindex->nHeight == 0) {
return false;
}
CBlockIndex *to_mark_failed_or_parked = pindex;
bool pindex_was_in_chain = false;
int disconnected = 0;
// We do not allow ActivateBestChain() to run while UnwindBlock() is
// running, as that could cause the tip to change while we disconnect
// blocks. (Note for backport of Core PR16849: we acquire
// LOCK(m_chainstate_mutex) in the Park, Invalidate and FinalizeBlock
// functions due to differences in our code)
AssertLockHeld(m_chainstate_mutex);
// We'll be acquiring and releasing cs_main below, to allow the validation
// callbacks to run. However, we should keep the block index in a
// consistent state as we disconnect blocks -- in particular we need to
// add equal-work blocks to setBlockIndexCandidates as we disconnect.
// To avoid walking the block index repeatedly in search of candidates,
// build a map once so that we can look up candidate blocks by chain
// work as we go.
std::multimap<const arith_uint256, CBlockIndex *> candidate_blocks_by_work;
{
LOCK(cs_main);
for (auto &entry : m_blockman.m_block_index) {
CBlockIndex *candidate = &entry.second;
// We don't need to put anything in our active chain into the
// multimap, because those candidates will be found and considered
// as we disconnect.
// Instead, consider only non-active-chain blocks that have at
// least as much work as where we expect the new tip to end up.
if (!m_chain.Contains(candidate) &&
!CBlockIndexWorkComparator()(candidate, pindex->pprev) &&
candidate->IsValid(BlockValidity::TRANSACTIONS) &&
candidate->HaveTxsDownloaded()) {
candidate_blocks_by_work.insert(
std::make_pair(candidate->nChainWork, candidate));
}
}
}
{
LOCK(cs_main);
// Lock for as long as disconnectpool is in scope to make sure
// UpdateMempoolForReorg is called after DisconnectTip without unlocking
// in between
LOCK(MempoolMutex());
constexpr int maxDisconnectPoolBlocks = 10;
bool ret = false;
DisconnectedBlockTransactions disconnectpool;
// After 10 blocks this becomes nullptr, so that DisconnectTip will
// stop giving us unwound block txs if we are doing a deep unwind.
DisconnectedBlockTransactions *optDisconnectPool = &disconnectpool;
// Disable thread safety analysis because we can't require m_mempool->cs
// as m_mempool can be null. We keep the runtime analysis though.
Defer deferred([&]() NO_THREAD_SAFETY_ANALYSIS {
AssertLockHeld(cs_main);
if (m_mempool && !disconnectpool.isEmpty()) {
AssertLockHeld(m_mempool->cs);
// DisconnectTip will add transactions to disconnectpool.
// When all unwinding is done and we are on a new tip, we must
// add all transactions back to the mempool against the new tip.
disconnectpool.updateMempoolForReorg(*this,
/* fAddToMempool = */ ret,
*m_mempool);
}
});
// Disconnect (descendants of) pindex, and mark them invalid.
while (true) {
if (ShutdownRequested()) {
break;
}
// Make sure the queue of validation callbacks doesn't grow
// unboundedly.
// FIXME this commented code is a regression and could cause OOM if
// a very old block is invalidated via the invalidateblock RPC.
// This can be uncommented if the main signals are moved away from
// cs_main or this code is refactored so that cs_main can be
// released at this point.
//
// LimitValidationInterfaceQueue();
if (!m_chain.Contains(pindex)) {
break;
}
if (m_mempool && disconnected == 0) {
// On first iteration, we grab all the mempool txs to preserve
// topological ordering. This has the side-effect of temporarily
// clearing the mempool, but we will re-add later in
// updateMempoolForReorg() (above). This technique guarantees
// mempool consistency as well as ensures that our topological
// entry_id index is always correct.
disconnectpool.importMempool(*m_mempool);
}
pindex_was_in_chain = true;
CBlockIndex *invalid_walk_tip = m_chain.Tip();
// ActivateBestChain considers blocks already in m_chain
// unconditionally valid already, so force disconnect away from it.
ret = DisconnectTip(state, optDisconnectPool);
++disconnected;
if (optDisconnectPool && disconnected > maxDisconnectPoolBlocks) {
// Stop using the disconnect pool after 10 blocks. After 10
// blocks we no longer add block tx's to the disconnectpool.
// However, when this scope ends we will reconcile what's
// in the pool with the new tip (in the deferred d'tor above).
optDisconnectPool = nullptr;
}
if (!ret) {
return false;
}
assert(invalid_walk_tip->pprev == m_chain.Tip());
// We immediately mark the disconnected blocks as invalid.
// This prevents a case where pruned nodes may fail to
// invalidateblock and be left unable to start as they have no tip
// candidates (as there are no blocks that meet the "have data and
// are not invalid per nStatus" criteria for inclusion in
// setBlockIndexCandidates).
invalid_walk_tip->nStatus =
invalidate ? invalid_walk_tip->nStatus.withFailed()
: invalid_walk_tip->nStatus.withParked();
m_blockman.m_dirty_blockindex.insert(invalid_walk_tip);
setBlockIndexCandidates.insert(invalid_walk_tip->pprev);
if (invalid_walk_tip == to_mark_failed_or_parked->pprev &&
(invalidate ? to_mark_failed_or_parked->nStatus.hasFailed()
: to_mark_failed_or_parked->nStatus.isParked())) {
// We only want to mark the last disconnected block as
// Failed (or Parked); its children need to be FailedParent (or
// ParkedParent) instead.
to_mark_failed_or_parked->nStatus =
(invalidate
? to_mark_failed_or_parked->nStatus.withFailed(false)
.withFailedParent()
: to_mark_failed_or_parked->nStatus.withParked(false)
.withParkedParent());
m_blockman.m_dirty_blockindex.insert(to_mark_failed_or_parked);
}
// Add any equal or more work headers to setBlockIndexCandidates
auto candidate_it = candidate_blocks_by_work.lower_bound(
invalid_walk_tip->pprev->nChainWork);
while (candidate_it != candidate_blocks_by_work.end()) {
if (!CBlockIndexWorkComparator()(candidate_it->second,
invalid_walk_tip->pprev)) {
setBlockIndexCandidates.insert(candidate_it->second);
candidate_it = candidate_blocks_by_work.erase(candidate_it);
} else {
++candidate_it;
}
}
// Track the last disconnected block, so we can correct its
// FailedParent (or ParkedParent) status in future iterations, or,
// if it's the last one, call InvalidChainFound on it.
to_mark_failed_or_parked = invalid_walk_tip;
}
}
CheckBlockIndex();
{
LOCK(cs_main);
if (m_chain.Contains(to_mark_failed_or_parked)) {
// If the to-be-marked invalid block is in the active chain,
// something is interfering and we can't proceed.
return false;
}
// Mark pindex (or the last disconnected block) as invalid (or parked),
// even when it never was in the main chain.
to_mark_failed_or_parked->nStatus =
invalidate ? to_mark_failed_or_parked->nStatus.withFailed()
: to_mark_failed_or_parked->nStatus.withParked();
m_blockman.m_dirty_blockindex.insert(to_mark_failed_or_parked);
if (invalidate) {
m_chainman.m_failed_blocks.insert(to_mark_failed_or_parked);
}
// If any new blocks somehow arrived while we were disconnecting
// (above), then the pre-calculation of what should go into
// setBlockIndexCandidates may have missed entries. This would
// technically be an inconsistency in the block index, but if we clean
// it up here, this should be an essentially unobservable error.
// Loop back over all block index entries and add any missing entries
// to setBlockIndexCandidates.
for (auto &[_, block_index] : m_blockman.m_block_index) {
if (block_index.IsValid(BlockValidity::TRANSACTIONS) &&
block_index.HaveTxsDownloaded() &&
!setBlockIndexCandidates.value_comp()(&block_index,
m_chain.Tip())) {
setBlockIndexCandidates.insert(&block_index);
}
}
if (invalidate) {
InvalidChainFound(to_mark_failed_or_parked);
}
}
// Only notify about a new block tip if the active chain was modified.
if (pindex_was_in_chain) {
m_chainman.GetNotifications().blockTip(
GetSynchronizationState(IsInitialBlockDownload()),
*to_mark_failed_or_parked->pprev);
}
return true;
}
bool Chainstate::InvalidateBlock(BlockValidationState &state,
CBlockIndex *pindex) {
AssertLockNotHeld(m_chainstate_mutex);
AssertLockNotHeld(::cs_main);
// See 'Note for backport of Core PR16849' in Chainstate::UnwindBlock
LOCK(m_chainstate_mutex);
return UnwindBlock(state, pindex, true);
}
bool Chainstate::ParkBlock(BlockValidationState &state, CBlockIndex *pindex) {
AssertLockNotHeld(m_chainstate_mutex);
AssertLockNotHeld(::cs_main);
// See 'Note for backport of Core PR16849' in Chainstate::UnwindBlock
LOCK(m_chainstate_mutex);
return UnwindBlock(state, pindex, false);
}
template <typename F>
bool Chainstate::UpdateFlagsForBlock(CBlockIndex *pindexBase,
CBlockIndex *pindex, F f) {
BlockStatus newStatus = f(pindex->nStatus);
if (pindex->nStatus != newStatus &&
(!pindexBase ||
pindex->GetAncestor(pindexBase->nHeight) == pindexBase)) {
pindex->nStatus = newStatus;
m_blockman.m_dirty_blockindex.insert(pindex);
if (newStatus.isValid()) {
m_chainman.m_failed_blocks.erase(pindex);
}
if (pindex->IsValid(BlockValidity::TRANSACTIONS) &&
pindex->HaveTxsDownloaded() &&
setBlockIndexCandidates.value_comp()(m_chain.Tip(), pindex)) {
setBlockIndexCandidates.insert(pindex);
}
return true;
}
return false;
}
template <typename F, typename C, typename AC>
void Chainstate::UpdateFlags(CBlockIndex *pindex, CBlockIndex *&pindexReset,
F f, C fChild, AC fAncestorWasChanged) {
AssertLockHeld(cs_main);
// Update the current block and ancestors; while we're doing this, identify
// which was the deepest ancestor we changed.
CBlockIndex *pindexDeepestChanged = pindex;
for (auto pindexAncestor = pindex; pindexAncestor != nullptr;
pindexAncestor = pindexAncestor->pprev) {
if (UpdateFlagsForBlock(nullptr, pindexAncestor, f)) {
pindexDeepestChanged = pindexAncestor;
}
}
if (pindexReset &&
pindexReset->GetAncestor(pindexDeepestChanged->nHeight) ==
pindexDeepestChanged) {
// reset pindexReset if it had a modified ancestor.
pindexReset = nullptr;
}
// Update all blocks under modified blocks.
for (auto &[_, block_index] : m_blockman.m_block_index) {
UpdateFlagsForBlock(pindex, &block_index, fChild);
UpdateFlagsForBlock(pindexDeepestChanged, &block_index,
fAncestorWasChanged);
}
}
void Chainstate::ResetBlockFailureFlags(CBlockIndex *pindex) {
AssertLockHeld(cs_main);
UpdateFlags(
pindex, m_chainman.m_best_invalid,
[](const BlockStatus status) {
return status.withClearedFailureFlags();
},
[](const BlockStatus status) {
return status.withClearedFailureFlags();
},
[](const BlockStatus status) {
return status.withFailedParent(false);
});
}
void Chainstate::UnparkBlockImpl(CBlockIndex *pindex, bool fClearChildren) {
AssertLockHeld(cs_main);
UpdateFlags(
pindex, m_chainman.m_best_parked,
[](const BlockStatus status) {
return status.withClearedParkedFlags();
},
[fClearChildren](const BlockStatus status) {
return fClearChildren ? status.withClearedParkedFlags()
: status.withParkedParent(false);
},
[](const BlockStatus status) {
return status.withParkedParent(false);
});
}
void Chainstate::UnparkBlockAndChildren(CBlockIndex *pindex) {
return UnparkBlockImpl(pindex, true);
}
void Chainstate::UnparkBlock(CBlockIndex *pindex) {
return UnparkBlockImpl(pindex, false);
}
bool Chainstate::AvalancheFinalizeBlock(CBlockIndex *pindex,
avalanche::Processor &avalanche) {
if (!pindex) {
return false;
}
if (!m_chain.Contains(pindex)) {
LogPrint(BCLog::AVALANCHE,
"The block to mark finalized by avalanche is not on the "
"active chain: %s\n",
pindex->GetBlockHash().ToString());
return false;
}
avalanche.cleanupStakingRewards(pindex->nHeight);
if (IsBlockAvalancheFinalized(pindex)) {
return true;
}
{
LOCK(cs_avalancheFinalizedBlockIndex);
m_avalancheFinalizedBlockIndex = pindex;
}
GetMainSignals().BlockFinalized(pindex);
return true;
}
void Chainstate::ClearAvalancheFinalizedBlock() {
LOCK(cs_avalancheFinalizedBlockIndex);
m_avalancheFinalizedBlockIndex = nullptr;
}
bool Chainstate::IsBlockAvalancheFinalized(const CBlockIndex *pindex) const {
LOCK(cs_avalancheFinalizedBlockIndex);
return pindex && m_avalancheFinalizedBlockIndex &&
m_avalancheFinalizedBlockIndex->GetAncestor(pindex->nHeight) ==
pindex;
}
/**
* Mark a block as having its data received and checked (up to
* BLOCK_VALID_TRANSACTIONS).
*/
void Chainstate::ReceivedBlockTransactions(const CBlock &block,
CBlockIndex *pindexNew,
const FlatFilePos &pos) {
pindexNew->nTx = block.vtx.size();
pindexNew->nSize = ::GetSerializeSize(block, PROTOCOL_VERSION);
pindexNew->nFile = pos.nFile;
pindexNew->nDataPos = pos.nPos;
pindexNew->nUndoPos = 0;
pindexNew->nStatus = pindexNew->nStatus.withData();
pindexNew->RaiseValidity(BlockValidity::TRANSACTIONS);
m_blockman.m_dirty_blockindex.insert(pindexNew);
if (pindexNew->UpdateChainStats()) {
// If pindexNew is the genesis block or all parents are
// BLOCK_VALID_TRANSACTIONS.
std::deque<CBlockIndex *> queue;
queue.push_back(pindexNew);
// Recursively process any descendant blocks that now may be eligible to
// be connected.
while (!queue.empty()) {
CBlockIndex *pindex = queue.front();
queue.pop_front();
pindex->UpdateChainStats();
if (pindex->nSequenceId == 0) {
// We assign a sequence is when transaction are received to
// prevent a miner from being able to broadcast a block but not
// its content. However, a sequence id may have been set
// manually, for instance via PreciousBlock, in which case, we
// don't need to assign one.
pindex->nSequenceId = nBlockSequenceId++;
}
if (m_chain.Tip() == nullptr ||
!setBlockIndexCandidates.value_comp()(pindex, m_chain.Tip())) {
setBlockIndexCandidates.insert(pindex);
}
std::pair<std::multimap<CBlockIndex *, CBlockIndex *>::iterator,
std::multimap<CBlockIndex *, CBlockIndex *>::iterator>
range = m_blockman.m_blocks_unlinked.equal_range(pindex);
while (range.first != range.second) {
std::multimap<CBlockIndex *, CBlockIndex *>::iterator it =
range.first;
queue.push_back(it->second);
range.first++;
m_blockman.m_blocks_unlinked.erase(it);
}
}
} else if (pindexNew->pprev &&
pindexNew->pprev->IsValid(BlockValidity::TREE)) {
m_blockman.m_blocks_unlinked.insert(
std::make_pair(pindexNew->pprev, pindexNew));
}
}
/**
* Return true if the provided block header is valid.
* Only verify PoW if blockValidationOptions is configured to do so.
* This allows validation of headers on which the PoW hasn't been done.
* For example: to validate template handed to mining software.
* Do not call this for any check that depends on the context.
* For context-dependent calls, see ContextualCheckBlockHeader.
*/
static bool CheckBlockHeader(const CBlockHeader &block,
BlockValidationState &state,
const Consensus::Params ¶ms,
BlockValidationOptions validationOptions) {
// Check proof of work matches claimed amount
if (validationOptions.shouldValidatePoW() &&
!CheckProofOfWork(block.GetHash(), block.nBits, params)) {
return state.Invalid(BlockValidationResult::BLOCK_INVALID_HEADER,
"high-hash", "proof of work failed");
}
return true;
}
bool CheckBlock(const CBlock &block, BlockValidationState &state,
const Consensus::Params ¶ms,
BlockValidationOptions validationOptions) {
// These are checks that are independent of context.
if (block.fChecked) {
return true;
}
// Check that the header is valid (particularly PoW). This is mostly
// redundant with the call in AcceptBlockHeader.
if (!CheckBlockHeader(block, state, params, validationOptions)) {
return false;
}
// Check the merkle root.
if (validationOptions.shouldValidateMerkleRoot()) {
bool mutated;
uint256 hashMerkleRoot2 = BlockMerkleRoot(block, &mutated);
if (block.hashMerkleRoot != hashMerkleRoot2) {
return state.Invalid(BlockValidationResult::BLOCK_MUTATED,
"bad-txnmrklroot", "hashMerkleRoot mismatch");
}
// Check for merkle tree malleability (CVE-2012-2459): repeating
// sequences of transactions in a block without affecting the merkle
// root of a block, while still invalidating it.
if (mutated) {
return state.Invalid(BlockValidationResult::BLOCK_MUTATED,
"bad-txns-duplicate", "duplicate transaction");
}
}
// All potential-corruption validation must be done before we do any
// transaction validation, as otherwise we may mark the header as invalid
// because we receive the wrong transactions for it.
// First transaction must be coinbase.
if (block.vtx.empty()) {
return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS,
"bad-cb-missing", "first tx is not coinbase");
}
// Size limits.
auto nMaxBlockSize = validationOptions.getExcessiveBlockSize();
// Bail early if there is no way this block is of reasonable size.
if ((block.vtx.size() * MIN_TRANSACTION_SIZE) > nMaxBlockSize) {
return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS,
"bad-blk-length", "size limits failed");
}
auto currentBlockSize = ::GetSerializeSize(block, PROTOCOL_VERSION);
if (currentBlockSize > nMaxBlockSize) {
return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS,
"bad-blk-length", "size limits failed");
}
// And a valid coinbase.
TxValidationState tx_state;
if (!CheckCoinbase(*block.vtx[0], tx_state)) {
return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS,
tx_state.GetRejectReason(),
strprintf("Coinbase check failed (txid %s) %s",
block.vtx[0]->GetId().ToString(),
tx_state.GetDebugMessage()));
}
// Check transactions for regularity, skipping the first. Note that this
// is the first time we check that all after the first are !IsCoinBase.
for (size_t i = 1; i < block.vtx.size(); i++) {
auto *tx = block.vtx[i].get();
if (!CheckRegularTransaction(*tx, tx_state)) {
return state.Invalid(
BlockValidationResult::BLOCK_CONSENSUS,
tx_state.GetRejectReason(),
strprintf("Transaction check failed (txid %s) %s",
tx->GetId().ToString(), tx_state.GetDebugMessage()));
}
}
if (validationOptions.shouldValidatePoW() &&
validationOptions.shouldValidateMerkleRoot()) {
block.fChecked = true;
}
return true;
}
bool HasValidProofOfWork(const std::vector<CBlockHeader> &headers,
const Consensus::Params &consensusParams) {
return std::all_of(headers.cbegin(), headers.cend(),
[&](const auto &header) {
return CheckProofOfWork(
header.GetHash(), header.nBits, consensusParams);
});
}
arith_uint256 CalculateHeadersWork(const std::vector<CBlockHeader> &headers) {
arith_uint256 total_work{0};
for (const CBlockHeader &header : headers) {
CBlockIndex dummy(header);
total_work += GetBlockProof(dummy);
}
return total_work;
}
/**
* Context-dependent validity checks.
* By "context", we mean only the previous block headers, but not the UTXO
* set; UTXO-related validity checks are done in ConnectBlock().
* NOTE: This function is not currently invoked by ConnectBlock(), so we
* should consider upgrade issues if we change which consensus rules are
* enforced in this function (eg by adding a new consensus rule). See comment
* in ConnectBlock().
* Note that -reindex-chainstate skips the validation that happens here!
*/
static bool ContextualCheckBlockHeader(
const CBlockHeader &block, BlockValidationState &state,
BlockManager &blockman, ChainstateManager &chainman,
const CBlockIndex *pindexPrev, NodeClock::time_point now,
const std::optional<CCheckpointData> &test_checkpoints = std::nullopt)
EXCLUSIVE_LOCKS_REQUIRED(::cs_main) {
AssertLockHeld(::cs_main);
assert(pindexPrev != nullptr);
const int nHeight = pindexPrev->nHeight + 1;
const CChainParams ¶ms = chainman.GetParams();
// Check proof of work
if (block.nBits != GetNextWorkRequired(pindexPrev, &block, params)) {
LogPrintf("bad bits after height: %d\n", pindexPrev->nHeight);
return state.Invalid(BlockValidationResult::BLOCK_INVALID_HEADER,
"bad-diffbits", "incorrect proof of work");
}
// Check against checkpoints
if (chainman.m_options.checkpoints_enabled) {
const CCheckpointData &checkpoints =
test_checkpoints ? test_checkpoints.value() : params.Checkpoints();
// Check that the block chain matches the known block chain up to a
// checkpoint.
if (!Checkpoints::CheckBlock(checkpoints, nHeight, block.GetHash())) {
LogPrint(BCLog::VALIDATION,
"ERROR: %s: rejected by checkpoint lock-in at %d\n",
__func__, nHeight);
return state.Invalid(BlockValidationResult::BLOCK_CHECKPOINT,
"checkpoint mismatch");
}
// Don't accept any forks from the main chain prior to last checkpoint.
// GetLastCheckpoint finds the last checkpoint in MapCheckpoints that's
// in our BlockIndex().
const CBlockIndex *pcheckpoint =
blockman.GetLastCheckpoint(checkpoints);
if (pcheckpoint && nHeight < pcheckpoint->nHeight) {
LogPrint(BCLog::VALIDATION,
"ERROR: %s: forked chain older than last checkpoint "
"(height %d)\n",
__func__, nHeight);
return state.Invalid(BlockValidationResult::BLOCK_CHECKPOINT,
"bad-fork-prior-to-checkpoint");
}
}
// Check timestamp against prev
if (block.GetBlockTime() <= pindexPrev->GetMedianTimePast()) {
return state.Invalid(BlockValidationResult::BLOCK_INVALID_HEADER,
"time-too-old", "block's timestamp is too early");
}
// Check timestamp
if (block.Time() > now + std::chrono::seconds{MAX_FUTURE_BLOCK_TIME}) {
return state.Invalid(BlockValidationResult::BLOCK_TIME_FUTURE,
"time-too-new",
"block timestamp too far in the future");
}
// Reject blocks with outdated version
if ((block.nVersion < 2 &&
DeploymentActiveAfter(pindexPrev, chainman,
Consensus::DEPLOYMENT_HEIGHTINCB)) ||
(block.nVersion < 3 &&
DeploymentActiveAfter(pindexPrev, chainman,
Consensus::DEPLOYMENT_DERSIG)) ||
(block.nVersion < 4 &&
DeploymentActiveAfter(pindexPrev, chainman,
Consensus::DEPLOYMENT_CLTV))) {
return state.Invalid(
BlockValidationResult::BLOCK_INVALID_HEADER,
strprintf("bad-version(0x%08x)", block.nVersion),
strprintf("rejected nVersion=0x%08x block", block.nVersion));
}
return true;
}
bool ContextualCheckTransactionForCurrentBlock(
const CBlockIndex &active_chain_tip, const Consensus::Params ¶ms,
const CTransaction &tx, TxValidationState &state) {
AssertLockHeld(cs_main);
// ContextualCheckTransactionForCurrentBlock() uses
// active_chain_tip.Height()+1 to evaluate nLockTime because when
// IsFinalTx() is called within AcceptBlock(), the height of the
// block *being* evaluated is what is used. Thus if we want to know if a
// transaction can be part of the *next* block, we need to call
// ContextualCheckTransaction() with one more than
// active_chain_tip.Height().
const int nBlockHeight = active_chain_tip.nHeight + 1;
// BIP113 will require that time-locked transactions have nLockTime set to
// less than the median time of the previous block they're contained in.
// When the next block is created its previous block will be the current
// chain tip, so we use that to calculate the median time passed to
// ContextualCheckTransaction().
// This time can also be used for consensus upgrades.
const int64_t nMedianTimePast{active_chain_tip.GetMedianTimePast()};
return ContextualCheckTransaction(params, tx, state, nBlockHeight,
nMedianTimePast);
}
/**
* NOTE: This function is not currently invoked by ConnectBlock(), so we
* should consider upgrade issues if we change which consensus rules are
* enforced in this function (eg by adding a new consensus rule). See comment
* in ConnectBlock().
* Note that -reindex-chainstate skips the validation that happens here!
*/
static bool ContextualCheckBlock(const CBlock &block,
BlockValidationState &state,
const ChainstateManager &chainman,
const CBlockIndex *pindexPrev) {
const int nHeight = pindexPrev == nullptr ? 0 : pindexPrev->nHeight + 1;
// Enforce BIP113 (Median Time Past).
bool enforce_locktime_median_time_past{false};
if (DeploymentActiveAfter(pindexPrev, chainman,
Consensus::DEPLOYMENT_CSV)) {
assert(pindexPrev != nullptr);
enforce_locktime_median_time_past = true;
}
const int64_t nMedianTimePast =
pindexPrev == nullptr ? 0 : pindexPrev->GetMedianTimePast();
const int64_t nLockTimeCutoff{enforce_locktime_median_time_past
? nMedianTimePast
: block.GetBlockTime()};
const Consensus::Params params = chainman.GetConsensus();
const bool fIsMagneticAnomalyEnabled =
IsMagneticAnomalyEnabled(params, pindexPrev);
// Check transactions:
// - canonical ordering
// - ensure they are finalized
// - check they have the minimum size
const CTransaction *prevTx = nullptr;
for (const auto &ptx : block.vtx) {
const CTransaction &tx = *ptx;
if (fIsMagneticAnomalyEnabled) {
if (prevTx && (tx.GetId() <= prevTx->GetId())) {
if (tx.GetId() == prevTx->GetId()) {
return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS,
"tx-duplicate",
strprintf("Duplicated transaction %s",
tx.GetId().ToString()));
}
return state.Invalid(
BlockValidationResult::BLOCK_CONSENSUS, "tx-ordering",
strprintf("Transaction order is invalid (%s < %s)",
tx.GetId().ToString(),
prevTx->GetId().ToString()));
}
if (prevTx || !tx.IsCoinBase()) {
prevTx = &tx;
}
}
TxValidationState tx_state;
if (!ContextualCheckTransaction(params, tx, tx_state, nHeight,
nLockTimeCutoff)) {
return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS,
tx_state.GetRejectReason(),
tx_state.GetDebugMessage());
}
}
// Enforce rule that the coinbase starts with serialized block height
if (DeploymentActiveAfter(pindexPrev, chainman,
Consensus::DEPLOYMENT_HEIGHTINCB)) {
CScript expect = CScript() << nHeight;
if (block.vtx[0]->vin[0].scriptSig.size() < expect.size() ||
!std::equal(expect.begin(), expect.end(),
block.vtx[0]->vin[0].scriptSig.begin())) {
return state.Invalid(BlockValidationResult::BLOCK_CONSENSUS,
"bad-cb-height",
"block height mismatch in coinbase");
}
}
return true;
}
/**
* If the provided block header is valid, add it to the block index.
*
* Returns true if the block is successfully added to the block index.
*/
bool ChainstateManager::AcceptBlockHeader(
const CBlockHeader &block, BlockValidationState &state,
CBlockIndex **ppindex, bool min_pow_checked,
const std::optional<CCheckpointData> &test_checkpoints) {
AssertLockHeld(cs_main);
const Config &config = this->GetConfig();
const CChainParams &chainparams = config.GetChainParams();
// Check for duplicate
BlockHash hash = block.GetHash();
BlockMap::iterator miSelf{m_blockman.m_block_index.find(hash)};
if (hash != chainparams.GetConsensus().hashGenesisBlock) {
if (miSelf != m_blockman.m_block_index.end()) {
// Block header is already known.
CBlockIndex *pindex = &(miSelf->second);
if (ppindex) {
*ppindex = pindex;
}
if (pindex->nStatus.isInvalid()) {
LogPrint(BCLog::VALIDATION, "%s: block %s is marked invalid\n",
__func__, hash.ToString());
return state.Invalid(
BlockValidationResult::BLOCK_CACHED_INVALID, "duplicate");
}
return true;
}
if (!CheckBlockHeader(block, state, chainparams.GetConsensus(),
BlockValidationOptions(config))) {
LogPrint(BCLog::VALIDATION,
"%s: Consensus::CheckBlockHeader: %s, %s\n", __func__,
hash.ToString(), state.ToString());
return false;
}
// Get prev block index
BlockMap::iterator mi{
m_blockman.m_block_index.find(block.hashPrevBlock)};
if (mi == m_blockman.m_block_index.end()) {
LogPrint(BCLog::VALIDATION,
"header %s has prev block not found: %s\n",
hash.ToString(), block.hashPrevBlock.ToString());
return state.Invalid(BlockValidationResult::BLOCK_MISSING_PREV,
"prev-blk-not-found");
}
CBlockIndex *pindexPrev = &((*mi).second);
assert(pindexPrev);
if (pindexPrev->nStatus.isInvalid()) {
LogPrint(BCLog::VALIDATION,
"header %s has prev block invalid: %s\n", hash.ToString(),
block.hashPrevBlock.ToString());
return state.Invalid(BlockValidationResult::BLOCK_INVALID_PREV,
"bad-prevblk");
}
if (!ContextualCheckBlockHeader(
block, state, m_blockman, *this, pindexPrev,
m_options.adjusted_time_callback(), test_checkpoints)) {
LogPrint(BCLog::VALIDATION,
"%s: Consensus::ContextualCheckBlockHeader: %s, %s\n",
__func__, hash.ToString(), state.ToString());
return false;
}
/* Determine if this block descends from any block which has been found
* invalid (m_failed_blocks), then mark pindexPrev and any blocks
* between them as failed. For example:
*
* D3
* /
* B2 - C2
* / \
* A D2 - E2 - F2
* \
* B1 - C1 - D1 - E1
*
* In the case that we attempted to reorg from E1 to F2, only to find
* C2 to be invalid, we would mark D2, E2, and F2 as BLOCK_FAILED_CHILD
* but NOT D3 (it was not in any of our candidate sets at the time).
*
* In any case D3 will also be marked as BLOCK_FAILED_CHILD at restart
* in LoadBlockIndex.
*/
if (!pindexPrev->IsValid(BlockValidity::SCRIPTS)) {
// The above does not mean "invalid": it checks if the previous
// block hasn't been validated up to BlockValidity::SCRIPTS. This is
// a performance optimization, in the common case of adding a new
// block to the tip, we don't need to iterate over the failed blocks
// list.
for (const CBlockIndex *failedit : m_failed_blocks) {
if (pindexPrev->GetAncestor(failedit->nHeight) == failedit) {
assert(failedit->nStatus.hasFailed());
CBlockIndex *invalid_walk = pindexPrev;
while (invalid_walk != failedit) {
invalid_walk->nStatus =
invalid_walk->nStatus.withFailedParent();
m_blockman.m_dirty_blockindex.insert(invalid_walk);
invalid_walk = invalid_walk->pprev;
}
LogPrint(BCLog::VALIDATION,
"header %s has prev block invalid: %s\n",
hash.ToString(), block.hashPrevBlock.ToString());
return state.Invalid(
BlockValidationResult::BLOCK_INVALID_PREV,
"bad-prevblk");
}
}
}
}
if (!min_pow_checked) {
LogPrint(BCLog::VALIDATION,
"%s: not adding new block header %s, missing anti-dos "
"proof-of-work validation\n",
__func__, hash.ToString());
return state.Invalid(BlockValidationResult::BLOCK_HEADER_LOW_WORK,
"too-little-chainwork");
}
CBlockIndex *pindex{m_blockman.AddToBlockIndex(block, m_best_header)};
if (ppindex) {
*ppindex = pindex;
}
return true;
}
// Exposed wrapper for AcceptBlockHeader
bool ChainstateManager::ProcessNewBlockHeaders(
const std::vector<CBlockHeader> &headers, bool min_pow_checked,
BlockValidationState &state, const CBlockIndex **ppindex,
const std::optional<CCheckpointData> &test_checkpoints) {
AssertLockNotHeld(cs_main);
{
LOCK(cs_main);
for (const CBlockHeader &header : headers) {
// Use a temp pindex instead of ppindex to avoid a const_cast
CBlockIndex *pindex = nullptr;
bool accepted = AcceptBlockHeader(
header, state, &pindex, min_pow_checked, test_checkpoints);
ActiveChainstate().CheckBlockIndex();
if (!accepted) {
return false;
}
if (ppindex) {
*ppindex = pindex;
}
}
}
if (NotifyHeaderTip(ActiveChainstate())) {
if (ActiveChainstate().IsInitialBlockDownload() && ppindex &&
*ppindex) {
const CBlockIndex &last_accepted{**ppindex};
const int64_t blocks_left{
(GetTime() - last_accepted.GetBlockTime()) /
this->GetConsensus().nPowTargetSpacing};
const double progress{100.0 * last_accepted.nHeight /
(last_accepted.nHeight + blocks_left)};
LogPrintf("Synchronizing blockheaders, height: %d (~%.2f%%)\n",
last_accepted.nHeight, progress);
}
}
return true;
}
void ChainstateManager::ReportHeadersPresync(const arith_uint256 &work,
int64_t height,
int64_t timestamp) {
AssertLockNotHeld(cs_main);
const auto &chainstate = ActiveChainstate();
{
LOCK(cs_main);
// Don't report headers presync progress if we already have a
// post-minchainwork header chain.
// This means we lose reporting for potentially legimate, but unlikely,
// deep reorgs, but prevent attackers that spam low-work headers from
// filling our logs.
if (m_best_header->nChainWork >=
UintToArith256(GetConsensus().nMinimumChainWork)) {
return;
}
// Rate limit headers presync updates to 4 per second, as these are not
// subject to DoS protection.
auto now = Now<SteadyMilliseconds>();
if (now < m_last_presync_update + 250ms) {
return;
}
m_last_presync_update = now;
}
bool initial_download = chainstate.IsInitialBlockDownload();
GetNotifications().headerTip(GetSynchronizationState(initial_download),
height, timestamp, /*presync=*/true);
if (initial_download) {
const int64_t blocks_left{(GetTime() - timestamp) /
GetConsensus().nPowTargetSpacing};
const double progress{100.0 * height / (height + blocks_left)};
LogPrintf("Pre-synchronizing blockheaders, height: %d (~%.2f%%)\n",
height, progress);
}
}
/**
* Store a block on disk.
*
* @param[in,out] pblock The block we want to accept.
* @param[in] fRequested A boolean to indicate if this block was requested
* from our peers.
* @param[in] dbp If non-null, the disk position of the block.
* @param[in,out] fNewBlock True if block was first received via this call.
* @param[in] min_pow_checked True if proof-of-work anti-DoS checks have
* been done by caller for headers chain
* @return True if the block is accepted as a valid block and written to disk.
*/
bool Chainstate::AcceptBlock(const std::shared_ptr<const CBlock> &pblock,
BlockValidationState &state, bool fRequested,
const FlatFilePos *dbp, bool *fNewBlock,
bool min_pow_checked) {
AssertLockHeld(cs_main);
const CBlock &block = *pblock;
if (fNewBlock) {
*fNewBlock = false;
}
CBlockIndex *pindex = nullptr;
bool accepted_header{
m_chainman.AcceptBlockHeader(block, state, &pindex, min_pow_checked)};
CheckBlockIndex();
if (!accepted_header) {
return false;
}
// Try to process all requested blocks that we don't have, but only
// process an unrequested block if it's new and has enough work to
// advance our tip, and isn't too many blocks ahead.
bool fAlreadyHave = pindex->nStatus.hasData();
// TODO: deal better with return value and error conditions for duplicate
// and unrequested blocks.
if (fAlreadyHave) {
return true;
}
// Compare block header timestamps and received times of the block and the
// chaintip. If they have the same chain height, use these diffs as a
// tie-breaker, attempting to pick the more honestly-mined block.
int64_t newBlockTimeDiff = std::llabs(pindex->GetReceivedTimeDiff());
int64_t chainTipTimeDiff =
m_chain.Tip() ? std::llabs(m_chain.Tip()->GetReceivedTimeDiff()) : 0;
bool isSameHeight =
m_chain.Tip() && (pindex->nChainWork == m_chain.Tip()->nChainWork);
if (isSameHeight) {
LogPrintf("Chain tip timestamp-to-received-time difference: hash=%s, "
"diff=%d\n",
m_chain.Tip()->GetBlockHash().ToString(), chainTipTimeDiff);
LogPrintf("New block timestamp-to-received-time difference: hash=%s, "
"diff=%d\n",
pindex->GetBlockHash().ToString(), newBlockTimeDiff);
}
bool fHasMoreOrSameWork =
(m_chain.Tip() ? pindex->nChainWork >= m_chain.Tip()->nChainWork
: true);
// Blocks that are too out-of-order needlessly limit the effectiveness of
// pruning, because pruning will not delete block files that contain any
// blocks which are too close in height to the tip. Apply this test
// regardless of whether pruning is enabled; it should generally be safe to
// not process unrequested blocks.
bool fTooFarAhead{pindex->nHeight >
m_chain.Height() + int(MIN_BLOCKS_TO_KEEP)};
// TODO: Decouple this function from the block download logic by removing
// fRequested
// This requires some new chain data structure to efficiently look up if a
// block is in a chain leading to a candidate for best tip, despite not
// being such a candidate itself.
// Note that this would break the getblockfrompeer RPC
// If we didn't ask for it:
if (!fRequested) {
// This is a previously-processed block that was pruned.
if (pindex->nTx != 0) {
return true;
}
// Don't process less-work chains.
if (!fHasMoreOrSameWork) {
return true;
}
// Block height is too high.
if (fTooFarAhead) {
return true;
}
// Protect against DoS attacks from low-work chains.
// If our tip is behind, a peer could try to send us
// low-work blocks on a fake chain that we would never
// request; don't process these.
if (pindex->nChainWork < m_chainman.MinimumChainWork()) {
return true;
}
}
const CChainParams ¶ms{m_chainman.GetParams()};
const Consensus::Params &consensusParams = params.GetConsensus();
if (!CheckBlock(block, state, consensusParams,
BlockValidationOptions(m_chainman.GetConfig())) ||
!ContextualCheckBlock(block, state, m_chainman, pindex->pprev)) {
if (state.IsInvalid() &&
state.GetResult() != BlockValidationResult::BLOCK_MUTATED) {
pindex->nStatus = pindex->nStatus.withFailed();
m_blockman.m_dirty_blockindex.insert(pindex);
}
return error("%s: %s (block %s)", __func__, state.ToString(),
block.GetHash().ToString());
}
// If connecting the new block would require rewinding more than one block
// from the active chain (i.e., a "deep reorg"), then mark the new block as
// parked. If it has enough work then it will be automatically unparked
// later, during FindMostWorkChain. We mark the block as parked at the very
// last minute so we can make sure everything is ready to be reorged if
// needed.
if (gArgs.GetBoolArg("-parkdeepreorg", true)) {
const CBlockIndex *pindexFork = m_chain.FindFork(pindex);
if (pindexFork && pindexFork->nHeight + 1 < m_chain.Height()) {
LogPrintf("Park block %s as it would cause a deep reorg.\n",
pindex->GetBlockHash().ToString());
pindex->nStatus = pindex->nStatus.withParked();
m_blockman.m_dirty_blockindex.insert(pindex);
}
}
// Header is valid/has work and the merkle tree is good.
// Relay now, but if it does not build on our best tip, let the
// SendMessages loop relay it.
if (!IsInitialBlockDownload() && m_chain.Tip() == pindex->pprev) {
GetMainSignals().NewPoWValidBlock(pindex, pblock);
}
// Write block to history file
if (fNewBlock) {
*fNewBlock = true;
}
try {
FlatFilePos blockPos{
m_blockman.SaveBlockToDisk(block, pindex->nHeight, m_chain, dbp)};
if (blockPos.IsNull()) {
state.Error(strprintf(
"%s: Failed to find position to write new block to disk",
__func__));
return false;
}
ReceivedBlockTransactions(block, pindex, blockPos);
} catch (const std::runtime_error &e) {
return AbortNode(state, std::string("System error: ") + e.what());
}
FlushStateToDisk(state, FlushStateMode::NONE);
CheckBlockIndex();
return true;
}
bool ChainstateManager::ProcessNewBlock(
const std::shared_ptr<const CBlock> &block, bool force_processing,
bool min_pow_checked, bool *new_block,
avalanche::Processor *const avalanche) {
AssertLockNotHeld(cs_main);
{
if (new_block) {
*new_block = false;
}
BlockValidationState state;
// CheckBlock() does not support multi-threaded block validation
// because CBlock::fChecked can cause data race.
// Therefore, the following critical section must include the
// CheckBlock() call as well.
LOCK(cs_main);
// Skipping AcceptBlock() for CheckBlock() failures means that we will
// never mark a block as invalid if CheckBlock() fails. This is
// protective against consensus failure if there are any unknown form
// s of block malleability that cause CheckBlock() to fail; see e.g.
// CVE-2012-2459 and
// https://lists.linuxfoundation.org/pipermail/bitcoin-dev/2019-February/016697.html.
// Because CheckBlock() is not very expensive, the anti-DoS benefits of
// caching failure (of a definitely-invalid block) are not substantial.
bool ret = CheckBlock(*block, state, this->GetConsensus(),
BlockValidationOptions(this->GetConfig()));
if (ret) {
// Store to disk
ret = ActiveChainstate().AcceptBlock(block, state, force_processing,
nullptr, new_block,
min_pow_checked);
}
if (!ret) {
GetMainSignals().BlockChecked(*block, state);
return error("%s: AcceptBlock FAILED (%s)", __func__,
state.ToString());
}
}
NotifyHeaderTip(ActiveChainstate());
// Only used to report errors, not invalidity - ignore it
BlockValidationState state;
if (!ActiveChainstate().ActivateBestChain(state, block, avalanche)) {
return error("%s: ActivateBestChain failed (%s)", __func__,
state.ToString());
}
return true;
}
MempoolAcceptResult
ChainstateManager::ProcessTransaction(const CTransactionRef &tx,
bool test_accept) {
AssertLockHeld(cs_main);
Chainstate &active_chainstate = ActiveChainstate();
if (!active_chainstate.GetMempool()) {
TxValidationState state;
state.Invalid(TxValidationResult::TX_NO_MEMPOOL, "no-mempool");
return MempoolAcceptResult::Failure(state);
}
auto result = AcceptToMemoryPool(active_chainstate, tx, GetTime(),
/*bypass_limits=*/false, test_accept);
active_chainstate.GetMempool()->check(
active_chainstate.CoinsTip(), active_chainstate.m_chain.Height() + 1);
return result;
}
bool TestBlockValidity(
BlockValidationState &state, const CChainParams ¶ms,
Chainstate &chainstate, const CBlock &block, CBlockIndex *pindexPrev,
const std::function<NodeClock::time_point()> &adjusted_time_callback,
BlockValidationOptions validationOptions) {
AssertLockHeld(cs_main);
assert(pindexPrev && pindexPrev == chainstate.m_chain.Tip());
CCoinsViewCache viewNew(&chainstate.CoinsTip());
BlockHash block_hash(block.GetHash());
CBlockIndex indexDummy(block);
indexDummy.pprev = pindexPrev;
indexDummy.nHeight = pindexPrev->nHeight + 1;
indexDummy.phashBlock = &block_hash;
// NOTE: CheckBlockHeader is called by CheckBlock
if (!ContextualCheckBlockHeader(block, state, chainstate.m_blockman,
chainstate.m_chainman, pindexPrev,
adjusted_time_callback())) {
return error("%s: Consensus::ContextualCheckBlockHeader: %s", __func__,
state.ToString());
}
if (!CheckBlock(block, state, params.GetConsensus(), validationOptions)) {
return error("%s: Consensus::CheckBlock: %s", __func__,
state.ToString());
}
if (!ContextualCheckBlock(block, state, chainstate.m_chainman,
pindexPrev)) {
return error("%s: Consensus::ContextualCheckBlock: %s", __func__,
state.ToString());
}
if (!chainstate.ConnectBlock(block, state, &indexDummy, viewNew,
validationOptions, nullptr, true)) {
return false;
}
assert(state.IsValid());
return true;
}
/* This function is called from the RPC code for pruneblockchain */
void PruneBlockFilesManual(Chainstate &active_chainstate,
int nManualPruneHeight) {
BlockValidationState state;
if (active_chainstate.FlushStateToDisk(state, FlushStateMode::NONE,
nManualPruneHeight)) {
LogPrintf("%s: failed to flush state (%s)\n", __func__,
state.ToString());
}
}
void Chainstate::LoadMempool(const fs::path &load_path,
FopenFn mockable_fopen_function) {
if (!m_mempool) {
return;
}
::LoadMempool(*m_mempool, load_path, *this, mockable_fopen_function);
m_mempool->SetLoadTried(!ShutdownRequested());
}
bool Chainstate::LoadChainTip() {
AssertLockHeld(cs_main);
const CCoinsViewCache &coins_cache = CoinsTip();
// Never called when the coins view is empty
assert(!coins_cache.GetBestBlock().IsNull());
const CBlockIndex *tip = m_chain.Tip();
if (tip && tip->GetBlockHash() == coins_cache.GetBestBlock()) {
return true;
}
// Load pointer to end of best chain
CBlockIndex *pindex =
m_blockman.LookupBlockIndex(coins_cache.GetBestBlock());
if (!pindex) {
return false;
}
m_chain.SetTip(*pindex);
PruneBlockIndexCandidates();
tip = m_chain.Tip();
LogPrintf(
"Loaded best chain: hashBestChain=%s height=%d date=%s progress=%f\n",
tip->GetBlockHash().ToString(), m_chain.Height(),
FormatISO8601DateTime(tip->GetBlockTime()),
GuessVerificationProgress(m_chainman.GetParams().TxData(), tip));
return true;
}
CVerifyDB::CVerifyDB(Notifications ¬ifications)
: m_notifications{notifications} {
m_notifications.progress(_("Verifying blocks…"), 0, false);
}
CVerifyDB::~CVerifyDB() {
m_notifications.progress(bilingual_str{}, 100, false);
}
VerifyDBResult CVerifyDB::VerifyDB(Chainstate &chainstate,
CCoinsView &coinsview, int nCheckLevel,
int nCheckDepth) {
AssertLockHeld(cs_main);
const Config &config = chainstate.m_chainman.GetConfig();
const CChainParams ¶ms = config.GetChainParams();
const Consensus::Params &consensusParams = params.GetConsensus();
if (chainstate.m_chain.Tip() == nullptr ||
chainstate.m_chain.Tip()->pprev == nullptr) {
return VerifyDBResult::SUCCESS;
}
// Verify blocks in the best chain
if (nCheckDepth <= 0 || nCheckDepth > chainstate.m_chain.Height()) {
nCheckDepth = chainstate.m_chain.Height();
}
nCheckLevel = std::max(0, std::min(4, nCheckLevel));
LogPrintf("Verifying last %i blocks at level %i\n", nCheckDepth,
nCheckLevel);
CCoinsViewCache coins(&coinsview);
CBlockIndex *pindex;
CBlockIndex *pindexFailure = nullptr;
int nGoodTransactions = 0;
BlockValidationState state;
int reportDone = 0;
bool skipped_no_block_data{false};
bool skipped_l3_checks{false};
LogPrintf("Verification progress: 0%%\n");
const bool is_snapshot_cs{!chainstate.m_from_snapshot_blockhash};
for (pindex = chainstate.m_chain.Tip(); pindex && pindex->pprev;
pindex = pindex->pprev) {
const int percentageDone = std::max(
1, std::min(99, (int)(((double)(chainstate.m_chain.Height() -
pindex->nHeight)) /
(double)nCheckDepth *
(nCheckLevel >= 4 ? 50 : 100))));
if (reportDone < percentageDone / 10) {
// report every 10% step
LogPrintf("Verification progress: %d%%\n", percentageDone);
reportDone = percentageDone / 10;
}
m_notifications.progress(_("Verifying blocks…"), percentageDone, false);
if (pindex->nHeight <= chainstate.m_chain.Height() - nCheckDepth) {
break;
}
if ((chainstate.m_blockman.IsPruneMode() || is_snapshot_cs) &&
!pindex->nStatus.hasData()) {
// If pruning or running under an assumeutxo snapshot, only go
// back as far as we have data.
LogPrintf("VerifyDB(): block verification stopping at height %d "
"(no data). This could be due to pruning or use of an "
"assumeutxo snapshot.\n",
pindex->nHeight);
skipped_no_block_data = true;
break;
}
CBlock block;
// check level 0: read from disk
if (!chainstate.m_blockman.ReadBlockFromDisk(block, *pindex)) {
LogPrintf(
"Verification error: ReadBlockFromDisk failed at %d, hash=%s\n",
pindex->nHeight, pindex->GetBlockHash().ToString());
return VerifyDBResult::CORRUPTED_BLOCK_DB;
}
// check level 1: verify block validity
if (nCheckLevel >= 1 && !CheckBlock(block, state, consensusParams,
BlockValidationOptions(config))) {
LogPrintf(
"Verification error: found bad block at %d, hash=%s (%s)\n",
pindex->nHeight, pindex->GetBlockHash().ToString(),
state.ToString());
return VerifyDBResult::CORRUPTED_BLOCK_DB;
}
// check level 2: verify undo validity
if (nCheckLevel >= 2 && pindex) {
CBlockUndo undo;
if (!pindex->GetUndoPos().IsNull()) {
if (!chainstate.m_blockman.UndoReadFromDisk(undo, *pindex)) {
LogPrintf("Verification error: found bad undo data at %d, "
"hash=%s\n",
pindex->nHeight,
pindex->GetBlockHash().ToString());
return VerifyDBResult::CORRUPTED_BLOCK_DB;
}
}
}
// check level 3: check for inconsistencies during memory-only
// disconnect of tip blocks
size_t curr_coins_usage = coins.DynamicMemoryUsage() +
chainstate.CoinsTip().DynamicMemoryUsage();
if (nCheckLevel >= 3) {
if (curr_coins_usage <= chainstate.m_coinstip_cache_size_bytes) {
assert(coins.GetBestBlock() == pindex->GetBlockHash());
DisconnectResult res =
chainstate.DisconnectBlock(block, pindex, coins);
if (res == DisconnectResult::FAILED) {
LogPrintf("Verification error: irrecoverable inconsistency "
"in block data at %d, hash=%s\n",
pindex->nHeight,
pindex->GetBlockHash().ToString());
return VerifyDBResult::CORRUPTED_BLOCK_DB;
}
if (res == DisconnectResult::UNCLEAN) {
nGoodTransactions = 0;
pindexFailure = pindex;
} else {
nGoodTransactions += block.vtx.size();
}
} else {
skipped_l3_checks = true;
}
}
if (ShutdownRequested()) {
return VerifyDBResult::INTERRUPTED;
}
}
if (pindexFailure) {
LogPrintf("Verification error: coin database inconsistencies found "
"(last %i blocks, %i good transactions before that)\n",
chainstate.m_chain.Height() - pindexFailure->nHeight + 1,
nGoodTransactions);
return VerifyDBResult::CORRUPTED_BLOCK_DB;
}
if (skipped_l3_checks) {
LogPrintf("Skipped verification of level >=3 (insufficient database "
"cache size). Consider increasing -dbcache.\n");
}
// store block count as we move pindex at check level >= 4
int block_count = chainstate.m_chain.Height() - pindex->nHeight;
// check level 4: try reconnecting blocks
if (nCheckLevel >= 4 && !skipped_l3_checks) {
while (pindex != chainstate.m_chain.Tip()) {
const int percentageDone = std::max(
1, std::min(99, 100 - int(double(chainstate.m_chain.Height() -
pindex->nHeight) /
double(nCheckDepth) * 50)));
if (reportDone < percentageDone / 10) {
// report every 10% step
LogPrintf("Verification progress: %d%%\n", percentageDone);
reportDone = percentageDone / 10;
}
m_notifications.progress(_("Verifying blocks…"), percentageDone,
false);
pindex = chainstate.m_chain.Next(pindex);
CBlock block;
if (!chainstate.m_blockman.ReadBlockFromDisk(block, *pindex)) {
LogPrintf("Verification error: ReadBlockFromDisk failed at %d, "
"hash=%s\n",
pindex->nHeight, pindex->GetBlockHash().ToString());
return VerifyDBResult::CORRUPTED_BLOCK_DB;
}
if (!chainstate.ConnectBlock(block, state, pindex, coins,
BlockValidationOptions(config))) {
LogPrintf("Verification error: found unconnectable block at "
"%d, hash=%s (%s)\n",
pindex->nHeight, pindex->GetBlockHash().ToString(),
state.ToString());
return VerifyDBResult::CORRUPTED_BLOCK_DB;
}
if (ShutdownRequested()) {
return VerifyDBResult::INTERRUPTED;
}
}
}
LogPrintf("Verification: No coin database inconsistencies in last %i "
"blocks (%i transactions)\n",
block_count, nGoodTransactions);
if (skipped_l3_checks) {
return VerifyDBResult::SKIPPED_L3_CHECKS;
}
if (skipped_no_block_data) {
return VerifyDBResult::SKIPPED_MISSING_BLOCKS;
}
return VerifyDBResult::SUCCESS;
}
/**
* Apply the effects of a block on the utxo cache, ignoring that it may already
* have been applied.
*/
bool Chainstate::RollforwardBlock(const CBlockIndex *pindex,
CCoinsViewCache &view) {
AssertLockHeld(cs_main);
// TODO: merge with ConnectBlock
CBlock block;
if (!m_blockman.ReadBlockFromDisk(block, *pindex)) {
return error("ReplayBlock(): ReadBlockFromDisk failed at %d, hash=%s",
pindex->nHeight, pindex->GetBlockHash().ToString());
}
for (const CTransactionRef &tx : block.vtx) {
// Pass check = true as every addition may be an overwrite.
AddCoins(view, *tx, pindex->nHeight, true);
}
for (const CTransactionRef &tx : block.vtx) {
if (tx->IsCoinBase()) {
continue;
}
for (const CTxIn &txin : tx->vin) {
view.SpendCoin(txin.prevout);
}
}
return true;
}
bool Chainstate::ReplayBlocks() {
LOCK(cs_main);
CCoinsView &db = this->CoinsDB();
CCoinsViewCache cache(&db);
std::vector<BlockHash> hashHeads = db.GetHeadBlocks();
if (hashHeads.empty()) {
// We're already in a consistent state.
return true;
}
if (hashHeads.size() != 2) {
return error("ReplayBlocks(): unknown inconsistent state");
}
m_chainman.GetNotifications().progress(_("Replaying blocks…"), 0, false);
LogPrintf("Replaying blocks\n");
// Old tip during the interrupted flush.
const CBlockIndex *pindexOld = nullptr;
// New tip during the interrupted flush.
const CBlockIndex *pindexNew;
// Latest block common to both the old and the new tip.
const CBlockIndex *pindexFork = nullptr;
if (m_blockman.m_block_index.count(hashHeads[0]) == 0) {
return error(
"ReplayBlocks(): reorganization to unknown block requested");
}
pindexNew = &(m_blockman.m_block_index[hashHeads[0]]);
if (!hashHeads[1].IsNull()) {
// The old tip is allowed to be 0, indicating it's the first flush.
if (m_blockman.m_block_index.count(hashHeads[1]) == 0) {
return error(
"ReplayBlocks(): reorganization from unknown block requested");
}
pindexOld = &(m_blockman.m_block_index[hashHeads[1]]);
pindexFork = LastCommonAncestor(pindexOld, pindexNew);
assert(pindexFork != nullptr);
}
// Rollback along the old branch.
while (pindexOld != pindexFork) {
if (pindexOld->nHeight > 0) {
// Never disconnect the genesis block.
CBlock block;
if (!m_blockman.ReadBlockFromDisk(block, *pindexOld)) {
return error("RollbackBlock(): ReadBlockFromDisk() failed at "
"%d, hash=%s",
pindexOld->nHeight,
pindexOld->GetBlockHash().ToString());
}
LogPrintf("Rolling back %s (%i)\n",
pindexOld->GetBlockHash().ToString(), pindexOld->nHeight);
DisconnectResult res = DisconnectBlock(block, pindexOld, cache);
if (res == DisconnectResult::FAILED) {
return error(
"RollbackBlock(): DisconnectBlock failed at %d, hash=%s",
pindexOld->nHeight, pindexOld->GetBlockHash().ToString());
}
// If DisconnectResult::UNCLEAN is returned, it means a non-existing
// UTXO was deleted, or an existing UTXO was overwritten. It
// corresponds to cases where the block-to-be-disconnect never had
// all its operations applied to the UTXO set. However, as both
// writing a UTXO and deleting a UTXO are idempotent operations, the
// result is still a version of the UTXO set with the effects of
// that block undone.
}
pindexOld = pindexOld->pprev;
}
// Roll forward from the forking point to the new tip.
int nForkHeight = pindexFork ? pindexFork->nHeight : 0;
for (int nHeight = nForkHeight + 1; nHeight <= pindexNew->nHeight;
++nHeight) {
const CBlockIndex &pindex{*Assert(pindexNew->GetAncestor(nHeight))};
LogPrintf("Rolling forward %s (%i)\n", pindex.GetBlockHash().ToString(),
nHeight);
m_chainman.GetNotifications().progress(
_("Replaying blocks…"),
(int)((nHeight - nForkHeight) * 100.0 /
(pindexNew->nHeight - nForkHeight)),
false);
if (!RollforwardBlock(&pindex, cache)) {
return false;
}
}
cache.SetBestBlock(pindexNew->GetBlockHash());
cache.Flush();
m_chainman.GetNotifications().progress(bilingual_str{}, 100, false);
return true;
}
// May NOT be used after any connections are up as much of the peer-processing
// logic assumes a consistent block index state
void Chainstate::UnloadBlockIndex() {
AssertLockHeld(::cs_main);
nBlockSequenceId = 1;
m_best_fork_tip = nullptr;
m_best_fork_base = nullptr;
setBlockIndexCandidates.clear();
}
bool ChainstateManager::LoadBlockIndex() {
AssertLockHeld(cs_main);
// Load block index from databases
bool needs_init = fReindex;
if (!fReindex) {
bool ret = m_blockman.LoadBlockIndexDB();
if (!ret) {
return false;
}
m_blockman.ScanAndUnlinkAlreadyPrunedFiles();
std::vector<CBlockIndex *> vSortedByHeight{
m_blockman.GetAllBlockIndices()};
std::sort(vSortedByHeight.begin(), vSortedByHeight.end(),
CBlockIndexHeightOnlyComparator());
// Find start of assumed-valid region.
int first_assumed_valid_height = std::numeric_limits<int>::max();
for (const CBlockIndex *block : vSortedByHeight) {
if (block->IsAssumedValid()) {
auto chainstates = GetAll();
// If we encounter an assumed-valid block index entry, ensure
// that we have one chainstate that tolerates assumed-valid
// entries and another that does not (i.e. the background
// validation chainstate), since assumed-valid entries should
// always be pending validation by a fully-validated chainstate.
auto any_chain = [&](auto fnc) {
return std::any_of(chainstates.cbegin(), chainstates.cend(),
fnc);
};
assert(any_chain([](auto chainstate) {
return chainstate->reliesOnAssumedValid();
}));
assert(any_chain([](auto chainstate) {
return !chainstate->reliesOnAssumedValid();
}));
first_assumed_valid_height = block->nHeight;
LogPrintf("Saw first assumedvalid block at height %d (%s)\n",
first_assumed_valid_height, block->ToString());
break;
}
}
for (CBlockIndex *pindex : vSortedByHeight) {
if (ShutdownRequested()) {
return false;
}
if (pindex->IsAssumedValid() ||
(pindex->IsValid(BlockValidity::TRANSACTIONS) &&
(pindex->HaveTxsDownloaded() || pindex->pprev == nullptr))) {
// Fill each chainstate's block candidate set. Only add
// assumed-valid blocks to the tip candidate set if the
// chainstate is allowed to rely on assumed-valid blocks.
//
// If all setBlockIndexCandidates contained the assumed-valid
// blocks, the background chainstate's ActivateBestChain() call
// would add assumed-valid blocks to the chain (based on how
// FindMostWorkChain() works). Obviously we don't want this
// since the purpose of the background validation chain is to
// validate assumed-valid blocks.
//
// Note: This is considering all blocks whose height is greater
// or equal to the first assumed-valid block to be assumed-valid
// blocks, and excluding them from the background chainstate's
// setBlockIndexCandidates set. This does mean that some blocks
// which are not technically assumed-valid (later blocks on a
// fork beginning before the first assumed-valid block) might
// not get added to the background chainstate, but this is ok,
// because they will still be attached to the active chainstate
// if they actually contain more work.
//
// Instead of this height-based approach, an earlier attempt was
// made at detecting "holistically" whether the block index
// under consideration relied on an assumed-valid ancestor, but
// this proved to be too slow to be practical.
for (Chainstate *chainstate : GetAll()) {
if (chainstate->reliesOnAssumedValid() ||
pindex->nHeight < first_assumed_valid_height) {
chainstate->setBlockIndexCandidates.insert(pindex);
}
}
}
if (pindex->nStatus.isInvalid() &&
(!m_best_invalid ||
pindex->nChainWork > m_best_invalid->nChainWork)) {
m_best_invalid = pindex;
}
if (pindex->nStatus.isOnParkedChain() &&
(!m_best_parked ||
pindex->nChainWork > m_best_parked->nChainWork)) {
m_best_parked = pindex;
}
if (pindex->IsValid(BlockValidity::TREE) &&
(m_best_header == nullptr ||
CBlockIndexWorkComparator()(m_best_header, pindex))) {
m_best_header = pindex;
}
}
needs_init = m_blockman.m_block_index.empty();
}
if (needs_init) {
// Everything here is for *new* reindex/DBs. Thus, though
// LoadBlockIndexDB may have set fReindex if we shut down
// mid-reindex previously, we don't check fReindex and
// instead only check it prior to LoadBlockIndexDB to set
// needs_init.
LogPrintf("Initializing databases...\n");
}
return true;
}
bool Chainstate::LoadGenesisBlock() {
LOCK(cs_main);
const CChainParams ¶ms{m_chainman.GetParams()};
// Check whether we're already initialized by checking for genesis in
// m_blockman.m_block_index. Note that we can't use m_chain here, since it
// is set based on the coins db, not the block index db, which is the only
// thing loaded at this point.
if (m_blockman.m_block_index.count(params.GenesisBlock().GetHash())) {
return true;
}
try {
const CBlock &block = params.GenesisBlock();
FlatFilePos blockPos{
m_blockman.SaveBlockToDisk(block, 0, m_chain, nullptr)};
if (blockPos.IsNull()) {
return error("%s: writing genesis block to disk failed", __func__);
}
CBlockIndex *pindex =
m_blockman.AddToBlockIndex(block, m_chainman.m_best_header);
ReceivedBlockTransactions(block, pindex, blockPos);
} catch (const std::runtime_error &e) {
return error("%s: failed to write genesis block: %s", __func__,
e.what());
}
return true;
}
void Chainstate::LoadExternalBlockFile(
FILE *fileIn, FlatFilePos *dbp,
std::multimap<BlockHash, FlatFilePos> *blocks_with_unknown_parent,
avalanche::Processor *const avalanche) {
AssertLockNotHeld(m_chainstate_mutex);
// Either both should be specified (-reindex), or neither (-loadblock).
assert(!dbp == !blocks_with_unknown_parent);
int64_t nStart = GetTimeMillis();
const CChainParams ¶ms{m_chainman.GetParams()};
int nLoaded = 0;
try {
// This takes over fileIn and calls fclose() on it in the CBufferedFile
// destructor. Make sure we have at least 2*MAX_TX_SIZE space in there
// so any transaction can fit in the buffer.
CBufferedFile blkdat(fileIn, 2 * MAX_TX_SIZE, MAX_TX_SIZE + 8, SER_DISK,
CLIENT_VERSION);
// nRewind indicates where to resume scanning in case something goes
// wrong, such as a block fails to deserialize.
uint64_t nRewind = blkdat.GetPos();
while (!blkdat.eof()) {
if (ShutdownRequested()) {
return;
}
blkdat.SetPos(nRewind);
// Start one byte further next time, in case of failure.
nRewind++;
// Remove former limit.
blkdat.SetLimit();
unsigned int nSize = 0;
try {
// Locate a header.
uint8_t buf[CMessageHeader::MESSAGE_START_SIZE];
blkdat.FindByte(std::byte(params.DiskMagic()[0]));
nRewind = blkdat.GetPos() + 1;
blkdat >> buf;
if (memcmp(buf, params.DiskMagic().data(),
CMessageHeader::MESSAGE_START_SIZE)) {
continue;
}
// Read size.
blkdat >> nSize;
if (nSize < 80) {
continue;
}
} catch (const std::exception &) {
// No valid block header found; don't complain.
// (this happens at the end of every blk.dat file)
break;
}
try {
// read block header
const uint64_t nBlockPos{blkdat.GetPos()};
if (dbp) {
dbp->nPos = nBlockPos;
}
blkdat.SetLimit(nBlockPos + nSize);
CBlockHeader header;
blkdat >> header;
const BlockHash hash{header.GetHash()};
// Skip the rest of this block (this may read from disk
// into memory); position to the marker before the next block,
// but it's still possible to rewind to the start of the
// current block (without a disk read).
nRewind = nBlockPos + nSize;
blkdat.SkipTo(nRewind);
// needs to remain available after the cs_main lock is released
// to avoid duplicate reads from disk
std::shared_ptr<CBlock> pblock{};
{
LOCK(cs_main);
// detect out of order blocks, and store them for later
if (hash != params.GetConsensus().hashGenesisBlock &&
!m_blockman.LookupBlockIndex(header.hashPrevBlock)) {
LogPrint(
BCLog::REINDEX,
"%s: Out of order block %s, parent %s not known\n",
__func__, hash.ToString(),
header.hashPrevBlock.ToString());
if (dbp && blocks_with_unknown_parent) {
blocks_with_unknown_parent->emplace(
header.hashPrevBlock, *dbp);
}
continue;
}
// process in case the block isn't known yet
const CBlockIndex *pindex =
m_blockman.LookupBlockIndex(hash);
if (!pindex || !pindex->nStatus.hasData()) {
// This block can be processed immediately; rewind to
// its start, read and deserialize it.
blkdat.SetPos(nBlockPos);
pblock = std::make_shared<CBlock>();
blkdat >> *pblock;
nRewind = blkdat.GetPos();
BlockValidationState state;
if (AcceptBlock(pblock, state, true, dbp, nullptr,
true)) {
nLoaded++;
}
if (state.IsError()) {
break;
}
} else if (hash != params.GetConsensus().hashGenesisBlock &&
pindex->nHeight % 1000 == 0) {
LogPrint(
BCLog::REINDEX,
"Block Import: already had block %s at height %d\n",
hash.ToString(), pindex->nHeight);
}
}
// Activate the genesis block so normal node progress can
// continue
if (hash == params.GetConsensus().hashGenesisBlock) {
BlockValidationState state;
if (!ActivateBestChain(state, nullptr, avalanche)) {
break;
}
}
if (m_blockman.IsPruneMode() && !fReindex && pblock) {
// Must update the tip for pruning to work while importing
// with -loadblock. This is a tradeoff to conserve disk
// space at the expense of time spent updating the tip to be
// able to prune. Otherwise, ActivateBestChain won't be
// called by the import process until after all of the block
// files are loaded. ActivateBestChain can be called by
// concurrent network message processing, but that is not
// reliable for the purpose of pruning while importing.
BlockValidationState state;
if (!ActivateBestChain(state, pblock, avalanche)) {
LogPrint(BCLog::REINDEX,
"failed to activate chain (%s)\n",
state.ToString());
break;
}
}
NotifyHeaderTip(*this);
if (!blocks_with_unknown_parent) {
continue;
}
// Recursively process earlier encountered successors of this
// block
std::deque<BlockHash> queue;
queue.push_back(hash);
while (!queue.empty()) {
BlockHash head = queue.front();
queue.pop_front();
auto range = blocks_with_unknown_parent->equal_range(head);
while (range.first != range.second) {
std::multimap<BlockHash, FlatFilePos>::iterator it =
range.first;
std::shared_ptr<CBlock> pblockrecursive =
std::make_shared<CBlock>();
if (m_blockman.ReadBlockFromDisk(*pblockrecursive,
it->second)) {
LogPrint(
BCLog::REINDEX,
"%s: Processing out of order child %s of %s\n",
__func__, pblockrecursive->GetHash().ToString(),
head.ToString());
LOCK(cs_main);
BlockValidationState dummy;
if (AcceptBlock(pblockrecursive, dummy, true,
&it->second, nullptr, true)) {
nLoaded++;
queue.push_back(pblockrecursive->GetHash());
}
}
range.first++;
blocks_with_unknown_parent->erase(it);
NotifyHeaderTip(*this);
}
}
} catch (const std::exception &e) {
// Historical bugs added extra data to the block files that does
// not deserialize cleanly. Commonly this data is between
// readable blocks, but it does not really matter. Such data is
// not fatal to the import process. The code that reads the
// block files deals with invalid data by simply ignoring it. It
// continues to search for the next {4 byte magic message start
// bytes + 4 byte length + block} that does deserialize cleanly
// and passes all of the other block validation checks dealing
// with POW and the merkle root, etc... We merely note with this
// informational log message when unexpected data is
// encountered. We could also be experiencing a storage system
// read error, or a read of a previous bad write. These are
// possible, but less likely scenarios. We don't have enough
// information to tell a difference here. The reindex process is
// not the place to attempt to clean and/or compact the block
// files. If so desired, a studious node operator may use
// knowledge of the fact that the block files are not entirely
// pristine in order to prepare a set of pristine, and perhaps
// ordered, block files for later reindexing.
LogPrint(BCLog::REINDEX,
"%s: unexpected data at file offset 0x%x - %s. "
"continuing\n",
__func__, (nRewind - 1), e.what());
}
}
} catch (const std::runtime_error &e) {
AbortNode(std::string("System error: ") + e.what());
}
LogPrintf("Loaded %i blocks from external file in %dms\n", nLoaded,
GetTimeMillis() - nStart);
}
void Chainstate::CheckBlockIndex() {
if (!m_chainman.ShouldCheckBlockIndex()) {
return;
}
LOCK(cs_main);
// During a reindex, we read the genesis block and call CheckBlockIndex
// before ActivateBestChain, so we have the genesis block in
// m_blockman.m_block_index but no active chain. (A few of the tests when
// iterating the block tree require that m_chain has been initialized.)
if (m_chain.Height() < 0) {
assert(m_blockman.m_block_index.size() <= 1);
return;
}
// Build forward-pointing map of the entire block tree.
std::multimap<CBlockIndex *, CBlockIndex *> forward;
for (auto &[_, block_index] : m_blockman.m_block_index) {
forward.emplace(block_index.pprev, &block_index);
}
assert(forward.size() == m_blockman.m_block_index.size());
std::pair<std::multimap<CBlockIndex *, CBlockIndex *>::iterator,
std::multimap<CBlockIndex *, CBlockIndex *>::iterator>
rangeGenesis = forward.equal_range(nullptr);
CBlockIndex *pindex = rangeGenesis.first->second;
rangeGenesis.first++;
// There is only one index entry with parent nullptr.
assert(rangeGenesis.first == rangeGenesis.second);
// Iterate over the entire block tree, using depth-first search.
// Along the way, remember whether there are blocks on the path from genesis
// block being explored which are the first to have certain properties.
size_t nNodes = 0;
int nHeight = 0;
// Oldest ancestor of pindex which is invalid.
CBlockIndex *pindexFirstInvalid = nullptr;
// Oldest ancestor of pindex which is parked.
CBlockIndex *pindexFirstParked = nullptr;
// Oldest ancestor of pindex which does not have data available.
CBlockIndex *pindexFirstMissing = nullptr;
// Oldest ancestor of pindex for which nTx == 0.
CBlockIndex *pindexFirstNeverProcessed = nullptr;
// Oldest ancestor of pindex which does not have BLOCK_VALID_TREE
// (regardless of being valid or not).
CBlockIndex *pindexFirstNotTreeValid = nullptr;
// Oldest ancestor of pindex which does not have BLOCK_VALID_TRANSACTIONS
// (regardless of being valid or not).
CBlockIndex *pindexFirstNotTransactionsValid = nullptr;
// Oldest ancestor of pindex which does not have BLOCK_VALID_CHAIN
// (regardless of being valid or not).
CBlockIndex *pindexFirstNotChainValid = nullptr;
// Oldest ancestor of pindex which does not have BLOCK_VALID_SCRIPTS
// (regardless of being valid or not).
CBlockIndex *pindexFirstNotScriptsValid = nullptr;
while (pindex != nullptr) {
nNodes++;
if (pindexFirstInvalid == nullptr && pindex->nStatus.hasFailed()) {
pindexFirstInvalid = pindex;
}
if (pindexFirstParked == nullptr && pindex->nStatus.isParked()) {
pindexFirstParked = pindex;
}
// Assumed-valid index entries will not have data since we haven't
// downloaded the full block yet.
if (pindexFirstMissing == nullptr && !pindex->nStatus.hasData() &&
!pindex->IsAssumedValid()) {
pindexFirstMissing = pindex;
}
if (pindexFirstNeverProcessed == nullptr && pindex->nTx == 0) {
pindexFirstNeverProcessed = pindex;
}
if (pindex->pprev != nullptr && pindexFirstNotTreeValid == nullptr &&
pindex->nStatus.getValidity() < BlockValidity::TREE) {
pindexFirstNotTreeValid = pindex;
}
if (pindex->pprev != nullptr && !pindex->IsAssumedValid()) {
if (pindexFirstNotTransactionsValid == nullptr &&
pindex->nStatus.getValidity() < BlockValidity::TRANSACTIONS) {
pindexFirstNotTransactionsValid = pindex;
}
if (pindexFirstNotChainValid == nullptr &&
pindex->nStatus.getValidity() < BlockValidity::CHAIN) {
pindexFirstNotChainValid = pindex;
}
if (pindexFirstNotScriptsValid == nullptr &&
pindex->nStatus.getValidity() < BlockValidity::SCRIPTS) {
pindexFirstNotScriptsValid = pindex;
}
}
// Begin: actual consistency checks.
if (pindex->pprev == nullptr) {
// Genesis block checks.
// Genesis block's hash must match.
assert(pindex->GetBlockHash() ==
m_chainman.GetConsensus().hashGenesisBlock);
// The current active chain's genesis block must be this block.
assert(pindex == m_chain.Genesis());
}
if (!pindex->HaveTxsDownloaded()) {
// nSequenceId can't be set positive for blocks that aren't linked
// (negative is used for preciousblock)
assert(pindex->nSequenceId <= 0);
}
// VALID_TRANSACTIONS is equivalent to nTx > 0 for all nodes (whether or
// not pruning has occurred). HAVE_DATA is only equivalent to nTx > 0
// (or VALID_TRANSACTIONS) if no pruning has occurred.
// Unless these indexes are assumed valid and pending block download on
// a background chainstate.
if (!m_blockman.m_have_pruned && !pindex->IsAssumedValid()) {
// If we've never pruned, then HAVE_DATA should be equivalent to nTx
// > 0
assert(pindex->nStatus.hasData() == (pindex->nTx > 0));
assert(pindexFirstMissing == pindexFirstNeverProcessed);
} else if (pindex->nStatus.hasData()) {
// If we have pruned, then we can only say that HAVE_DATA implies
// nTx > 0
assert(pindex->nTx > 0);
}
if (pindex->nStatus.hasUndo()) {
assert(pindex->nStatus.hasData());
}
if (pindex->IsAssumedValid()) {
// Assumed-valid blocks should have some nTx value.
assert(pindex->nTx > 0);
// Assumed-valid blocks should connect to the main chain.
assert(pindex->nStatus.getValidity() >= BlockValidity::TREE);
} else {
// Otherwise there should only be an nTx value if we have
// actually seen a block's transactions.
// This is pruning-independent.
assert((pindex->nStatus.getValidity() >=
BlockValidity::TRANSACTIONS) == (pindex->nTx > 0));
}
// All parents having had data (at some point) is equivalent to all
// parents being VALID_TRANSACTIONS, which is equivalent to
// HaveTxsDownloaded(). All parents having had data (at some point) is
// equivalent to all parents being VALID_TRANSACTIONS, which is
// equivalent to HaveTxsDownloaded().
assert((pindexFirstNeverProcessed == nullptr) ==
(pindex->HaveTxsDownloaded()));
assert((pindexFirstNotTransactionsValid == nullptr) ==
(pindex->HaveTxsDownloaded()));
// nHeight must be consistent.
assert(pindex->nHeight == nHeight);
// For every block except the genesis block, the chainwork must be
// larger than the parent's.
assert(pindex->pprev == nullptr ||
pindex->nChainWork >= pindex->pprev->nChainWork);
// The pskip pointer must point back for all but the first 2 blocks.
assert(nHeight < 2 ||
(pindex->pskip && (pindex->pskip->nHeight < nHeight)));
// All m_blockman.m_block_index entries must at least be TREE valid
assert(pindexFirstNotTreeValid == nullptr);
if (pindex->nStatus.getValidity() >= BlockValidity::TREE) {
// TREE valid implies all parents are TREE valid
assert(pindexFirstNotTreeValid == nullptr);
}
if (pindex->nStatus.getValidity() >= BlockValidity::CHAIN) {
// CHAIN valid implies all parents are CHAIN valid
assert(pindexFirstNotChainValid == nullptr);
}
if (pindex->nStatus.getValidity() >= BlockValidity::SCRIPTS) {
// SCRIPTS valid implies all parents are SCRIPTS valid
assert(pindexFirstNotScriptsValid == nullptr);
}
if (pindexFirstInvalid == nullptr) {
// Checks for not-invalid blocks.
// The failed mask cannot be set for blocks without invalid parents.
assert(!pindex->nStatus.isInvalid());
}
if (pindexFirstParked == nullptr) {
// Checks for not-parked blocks.
// The parked mask cannot be set for blocks without parked parents.
// (i.e., hasParkedParent only if an ancestor is properly parked).
assert(!pindex->nStatus.isOnParkedChain());
}
if (!CBlockIndexWorkComparator()(pindex, m_chain.Tip()) &&
pindexFirstNeverProcessed == nullptr) {
if (pindexFirstInvalid == nullptr) {
// Don't perform this check for the background chainstate since
// its setBlockIndexCandidates shouldn't have some entries (i.e.
// those past the snapshot block) which do exist in the block
// index for the active chainstate.
if (this == &m_chainman.ActiveChainstate()) {
// If this block sorts at least as good as the current tip
// and is valid and we have all data for its parents, it
// must be in setBlockIndexCandidates or be parked.
if (pindexFirstMissing == nullptr) {
assert(pindex->nStatus.isOnParkedChain() ||
setBlockIndexCandidates.count(pindex));
}
// m_chain.Tip() must also be there even if some data has
// been pruned.
if (pindex == m_chain.Tip()) {
assert(setBlockIndexCandidates.count(pindex));
}
}
// If some parent is missing, then it could be that this block
// was in setBlockIndexCandidates but had to be removed because
// of the missing data. In this case it must be in
// m_blocks_unlinked -- see test below.
}
} else {
// If this block sorts worse than the current tip or some ancestor's
// block has never been seen, it cannot be in
// setBlockIndexCandidates.
assert(setBlockIndexCandidates.count(pindex) == 0);
}
// Check whether this block is in m_blocks_unlinked.
std::pair<std::multimap<CBlockIndex *, CBlockIndex *>::iterator,
std::multimap<CBlockIndex *, CBlockIndex *>::iterator>
rangeUnlinked =
m_blockman.m_blocks_unlinked.equal_range(pindex->pprev);
bool foundInUnlinked = false;
while (rangeUnlinked.first != rangeUnlinked.second) {
assert(rangeUnlinked.first->first == pindex->pprev);
if (rangeUnlinked.first->second == pindex) {
foundInUnlinked = true;
break;
}
rangeUnlinked.first++;
}
if (pindex->pprev && pindex->nStatus.hasData() &&
pindexFirstNeverProcessed != nullptr &&
pindexFirstInvalid == nullptr) {
// If this block has block data available, some parent was never
// received, and has no invalid parents, it must be in
// m_blocks_unlinked.
assert(foundInUnlinked);
}
if (!pindex->nStatus.hasData()) {
// Can't be in m_blocks_unlinked if we don't HAVE_DATA
assert(!foundInUnlinked);
}
if (pindexFirstMissing == nullptr) {
// We aren't missing data for any parent -- cannot be in
// m_blocks_unlinked.
assert(!foundInUnlinked);
}
if (pindex->pprev && pindex->nStatus.hasData() &&
pindexFirstNeverProcessed == nullptr &&
pindexFirstMissing != nullptr) {
// We HAVE_DATA for this block, have received data for all parents
// at some point, but we're currently missing data for some parent.
// We must have pruned.
assert(m_blockman.m_have_pruned);
// This block may have entered m_blocks_unlinked if:
// - it has a descendant that at some point had more work than the
// tip, and
// - we tried switching to that descendant but were missing
// data for some intermediate block between m_chain and the
// tip.
// So if this block is itself better than m_chain.Tip() and it
// wasn't in
// setBlockIndexCandidates, then it must be in m_blocks_unlinked.
if (!CBlockIndexWorkComparator()(pindex, m_chain.Tip()) &&
setBlockIndexCandidates.count(pindex) == 0) {
if (pindexFirstInvalid == nullptr) {
assert(foundInUnlinked);
}
}
}
// Perhaps too slow
// assert(pindex->GetBlockHash() == pindex->GetBlockHeader().GetHash());
// End: actual consistency checks.
// Try descending into the first subnode.
std::pair<std::multimap<CBlockIndex *, CBlockIndex *>::iterator,
std::multimap<CBlockIndex *, CBlockIndex *>::iterator>
range = forward.equal_range(pindex);
if (range.first != range.second) {
// A subnode was found.
pindex = range.first->second;
nHeight++;
continue;
}
// This is a leaf node. Move upwards until we reach a node of which we
// have not yet visited the last child.
while (pindex) {
// We are going to either move to a parent or a sibling of pindex.
// If pindex was the first with a certain property, unset the
// corresponding variable.
if (pindex == pindexFirstInvalid) {
pindexFirstInvalid = nullptr;
}
if (pindex == pindexFirstParked) {
pindexFirstParked = nullptr;
}
if (pindex == pindexFirstMissing) {
pindexFirstMissing = nullptr;
}
if (pindex == pindexFirstNeverProcessed) {
pindexFirstNeverProcessed = nullptr;
}
if (pindex == pindexFirstNotTreeValid) {
pindexFirstNotTreeValid = nullptr;
}
if (pindex == pindexFirstNotTransactionsValid) {
pindexFirstNotTransactionsValid = nullptr;
}
if (pindex == pindexFirstNotChainValid) {
pindexFirstNotChainValid = nullptr;
}
if (pindex == pindexFirstNotScriptsValid) {
pindexFirstNotScriptsValid = nullptr;
}
// Find our parent.
CBlockIndex *pindexPar = pindex->pprev;
// Find which child we just visited.
std::pair<std::multimap<CBlockIndex *, CBlockIndex *>::iterator,
std::multimap<CBlockIndex *, CBlockIndex *>::iterator>
rangePar = forward.equal_range(pindexPar);
while (rangePar.first->second != pindex) {
// Our parent must have at least the node we're coming from as
// child.
assert(rangePar.first != rangePar.second);
rangePar.first++;
}
// Proceed to the next one.
rangePar.first++;
if (rangePar.first != rangePar.second) {
// Move to the sibling.
pindex = rangePar.first->second;
break;
} else {
// Move up further.
pindex = pindexPar;
nHeight--;
continue;
}
}
}
// Check that we actually traversed the entire map.
assert(nNodes == forward.size());
}
std::string Chainstate::ToString() {
AssertLockHeld(::cs_main);
CBlockIndex *tip = m_chain.Tip();
return strprintf("Chainstate [%s] @ height %d (%s)",
m_from_snapshot_blockhash ? "snapshot" : "ibd",
tip ? tip->nHeight : -1,
tip ? tip->GetBlockHash().ToString() : "null");
}
bool Chainstate::ResizeCoinsCaches(size_t coinstip_size, size_t coinsdb_size) {
AssertLockHeld(::cs_main);
if (coinstip_size == m_coinstip_cache_size_bytes &&
coinsdb_size == m_coinsdb_cache_size_bytes) {
// Cache sizes are unchanged, no need to continue.
return true;
}
size_t old_coinstip_size = m_coinstip_cache_size_bytes;
m_coinstip_cache_size_bytes = coinstip_size;
m_coinsdb_cache_size_bytes = coinsdb_size;
CoinsDB().ResizeCache(coinsdb_size);
LogPrintf("[%s] resized coinsdb cache to %.1f MiB\n", this->ToString(),
coinsdb_size * (1.0 / 1024 / 1024));
LogPrintf("[%s] resized coinstip cache to %.1f MiB\n", this->ToString(),
coinstip_size * (1.0 / 1024 / 1024));
BlockValidationState state;
bool ret;
if (coinstip_size > old_coinstip_size) {
// Likely no need to flush if cache sizes have grown.
ret = FlushStateToDisk(state, FlushStateMode::IF_NEEDED);
} else {
// Otherwise, flush state to disk and deallocate the in-memory coins
// map.
ret = FlushStateToDisk(state, FlushStateMode::ALWAYS);
}
return ret;
}
//! Guess how far we are in the verification process at the given block index
//! require cs_main if pindex has not been validated yet (because the chain's
//! transaction count might be unset) This conditional lock requirement might be
//! confusing, see: https://github.com/bitcoin/bitcoin/issues/15994
double GuessVerificationProgress(const ChainTxData &data,
const CBlockIndex *pindex) {
if (pindex == nullptr) {
return 0.0;
}
int64_t nNow = time(nullptr);
double fTxTotal;
if (pindex->GetChainTxCount() <= data.nTxCount) {
fTxTotal = data.nTxCount + (nNow - data.nTime) * data.dTxRate;
} else {
fTxTotal = pindex->GetChainTxCount() +
(nNow - pindex->GetBlockTime()) * data.dTxRate;
}
return std::min<double>(pindex->GetChainTxCount() / fTxTotal, 1.0);
}
std::optional<BlockHash> ChainstateManager::SnapshotBlockhash() const {
LOCK(::cs_main);
if (m_active_chainstate && m_active_chainstate->m_from_snapshot_blockhash) {
// If a snapshot chainstate exists, it will always be our active.
return m_active_chainstate->m_from_snapshot_blockhash;
}
return std::nullopt;
}
std::vector<Chainstate *> ChainstateManager::GetAll() {
LOCK(::cs_main);
std::vector<Chainstate *> out;
for (Chainstate *pchainstate :
{m_ibd_chainstate.get(), m_snapshot_chainstate.get()}) {
if (this->IsUsable(pchainstate)) {
out.push_back(pchainstate);
}
}
return out;
}
Chainstate &ChainstateManager::InitializeChainstate(CTxMemPool *mempool) {
AssertLockHeld(::cs_main);
assert(!m_ibd_chainstate);
assert(!m_active_chainstate);
m_ibd_chainstate = std::make_unique<Chainstate>(mempool, m_blockman, *this);
m_active_chainstate = m_ibd_chainstate.get();
return *m_active_chainstate;
}
const AssumeutxoData *ExpectedAssumeutxo(const int height,
const CChainParams &chainparams) {
const MapAssumeutxo &valid_assumeutxos_map = chainparams.Assumeutxo();
const auto assumeutxo_found = valid_assumeutxos_map.find(height);
if (assumeutxo_found != valid_assumeutxos_map.end()) {
return &assumeutxo_found->second;
}
return nullptr;
}
static bool DeleteCoinsDBFromDisk(const fs::path &db_path, bool is_snapshot)
EXCLUSIVE_LOCKS_REQUIRED(::cs_main) {
AssertLockHeld(::cs_main);
if (is_snapshot) {
fs::path base_blockhash_path =
db_path / node::SNAPSHOT_BLOCKHASH_FILENAME;
try {
const bool existed{fs::remove(base_blockhash_path)};
if (!existed) {
LogPrintf("[snapshot] snapshot chainstate dir being removed "
"lacks %s file\n",
fs::PathToString(node::SNAPSHOT_BLOCKHASH_FILENAME));
}
} catch (const fs::filesystem_error &e) {
LogPrintf("[snapshot] failed to remove file %s: %s\n",
fs::PathToString(base_blockhash_path),
fsbridge::get_filesystem_error_message(e));
}
}
std::string path_str = fs::PathToString(db_path);
LogPrintf("Removing leveldb dir at %s\n", path_str);
// We have to destruct before this call leveldb::DB in order to release the
// db lock, otherwise `DestroyDB` will fail. See `leveldb::~DBImpl()`.
const bool destroyed = dbwrapper::DestroyDB(path_str, {}).ok();
if (!destroyed) {
LogPrintf("error: leveldb DestroyDB call failed on %s\n", path_str);
}
// Datadir should be removed from filesystem; otherwise initialization may
// detect it on subsequent statups and get confused.
//
// If the base_blockhash_path removal above fails in the case of snapshot
// chainstates, this will return false since leveldb won't remove a
// non-empty directory.
return destroyed && !fs::exists(db_path);
}
bool ChainstateManager::ActivateSnapshot(AutoFile &coins_file,
const SnapshotMetadata &metadata,
bool in_memory) {
BlockHash base_blockhash = metadata.m_base_blockhash;
if (this->SnapshotBlockhash()) {
LogPrintf("[snapshot] can't activate a snapshot-based chainstate more "
"than once\n");
return false;
}
int64_t current_coinsdb_cache_size{0};
int64_t current_coinstip_cache_size{0};
// Cache percentages to allocate to each chainstate.
//
// These particular percentages don't matter so much since they will only be
// relevant during snapshot activation; caches are rebalanced at the
// conclusion of this function. We want to give (essentially) all available
// cache capacity to the snapshot to aid the bulk load later in this
// function.
static constexpr double IBD_CACHE_PERC = 0.01;
static constexpr double SNAPSHOT_CACHE_PERC = 0.99;
{
LOCK(::cs_main);
// Resize the coins caches to ensure we're not exceeding memory limits.
//
// Allocate the majority of the cache to the incoming snapshot
// chainstate, since (optimistically) getting to its tip will be the top
// priority. We'll need to call `MaybeRebalanceCaches()` once we're done
// with this function to ensure the right allocation (including the
// possibility that no snapshot was activated and that we should restore
// the active chainstate caches to their original size).
//
current_coinsdb_cache_size =
this->ActiveChainstate().m_coinsdb_cache_size_bytes;
current_coinstip_cache_size =
this->ActiveChainstate().m_coinstip_cache_size_bytes;
// Temporarily resize the active coins cache to make room for the
// newly-created snapshot chain.
this->ActiveChainstate().ResizeCoinsCaches(
static_cast<size_t>(current_coinstip_cache_size * IBD_CACHE_PERC),
static_cast<size_t>(current_coinsdb_cache_size * IBD_CACHE_PERC));
}
auto snapshot_chainstate =
WITH_LOCK(::cs_main, return std::make_unique<Chainstate>(
/* mempool */ nullptr, m_blockman, *this,
base_blockhash));
{
LOCK(::cs_main);
snapshot_chainstate->InitCoinsDB(
static_cast<size_t>(current_coinsdb_cache_size *
SNAPSHOT_CACHE_PERC),
in_memory, false, "chainstate");
snapshot_chainstate->InitCoinsCache(static_cast<size_t>(
current_coinstip_cache_size * SNAPSHOT_CACHE_PERC));
}
bool snapshot_ok = this->PopulateAndValidateSnapshot(*snapshot_chainstate,
coins_file, metadata);
// If not in-memory, persist the base blockhash for use during subsequent
// initialization.
if (!in_memory) {
LOCK(::cs_main);
if (!node::WriteSnapshotBaseBlockhash(*snapshot_chainstate)) {
snapshot_ok = false;
}
}
if (!snapshot_ok) {
LOCK(::cs_main);
this->MaybeRebalanceCaches();
// PopulateAndValidateSnapshot can return (in error) before the leveldb
// datadir has been created, so only attempt removal if we got that far.
if (auto snapshot_datadir = node::FindSnapshotChainstateDir()) {
// We have to destruct leveldb::DB in order to release the db lock,
// otherwise DestroyDB() (in DeleteCoinsDBFromDisk()) will fail. See
// `leveldb::~DBImpl()`. Destructing the chainstate (and so
// resetting the coinsviews object) does this.
snapshot_chainstate.reset();
bool removed =
DeleteCoinsDBFromDisk(*snapshot_datadir, /*is_snapshot=*/true);
if (!removed) {
AbortNode(
strprintf("Failed to remove snapshot chainstate dir (%s). "
"Manually remove it before restarting.\n",
fs::PathToString(*snapshot_datadir)));
}
}
return false;
}
{
LOCK(::cs_main);
assert(!m_snapshot_chainstate);
m_snapshot_chainstate.swap(snapshot_chainstate);
const bool chaintip_loaded = m_snapshot_chainstate->LoadChainTip();
assert(chaintip_loaded);
m_active_chainstate = m_snapshot_chainstate.get();
LogPrintf("[snapshot] successfully activated snapshot %s\n",
base_blockhash.ToString());
LogPrintf("[snapshot] (%.2f MB)\n",
m_snapshot_chainstate->CoinsTip().DynamicMemoryUsage() /
(1000 * 1000));
this->MaybeRebalanceCaches();
}
return true;
}
static void FlushSnapshotToDisk(CCoinsViewCache &coins_cache,
bool snapshot_loaded) {
LOG_TIME_MILLIS_WITH_CATEGORY_MSG_ONCE(
strprintf("%s (%.2f MB)",
snapshot_loaded ? "saving snapshot chainstate"
: "flushing coins cache",
coins_cache.DynamicMemoryUsage() / (1000 * 1000)),
BCLog::LogFlags::ALL);
coins_cache.Flush();
}
struct StopHashingException : public std::exception {
const char *what() const throw() override {
return "ComputeUTXOStats interrupted by shutdown.";
}
};
static void SnapshotUTXOHashBreakpoint() {
if (ShutdownRequested()) {
throw StopHashingException();
}
}
bool ChainstateManager::PopulateAndValidateSnapshot(
Chainstate &snapshot_chainstate, AutoFile &coins_file,
const SnapshotMetadata &metadata) {
// It's okay to release cs_main before we're done using `coins_cache`
// because we know that nothing else will be referencing the newly created
// snapshot_chainstate yet.
CCoinsViewCache &coins_cache =
*WITH_LOCK(::cs_main, return &snapshot_chainstate.CoinsTip());
BlockHash base_blockhash = metadata.m_base_blockhash;
CBlockIndex *snapshot_start_block = WITH_LOCK(
::cs_main, return m_blockman.LookupBlockIndex(base_blockhash));
if (!snapshot_start_block) {
// Needed for ComputeUTXOStats and ExpectedAssumeutxo to determine the
// height and to avoid a crash when base_blockhash.IsNull()
LogPrintf("[snapshot] Did not find snapshot start blockheader %s\n",
base_blockhash.ToString());
return false;
}
int base_height = snapshot_start_block->nHeight;
auto maybe_au_data = ExpectedAssumeutxo(base_height, GetParams());
if (!maybe_au_data) {
LogPrintf("[snapshot] assumeutxo height in snapshot metadata not "
"recognized (%d) - refusing to load snapshot\n",
base_height);
return false;
}
const AssumeutxoData &au_data = *maybe_au_data;
COutPoint outpoint;
Coin coin;
const uint64_t coins_count = metadata.m_coins_count;
uint64_t coins_left = metadata.m_coins_count;
LogPrintf("[snapshot] loading coins from snapshot %s\n",
base_blockhash.ToString());
int64_t coins_processed{0};
while (coins_left > 0) {
try {
coins_file >> outpoint;
coins_file >> coin;
} catch (const std::ios_base::failure &) {
LogPrintf("[snapshot] bad snapshot format or truncated snapshot "
"after deserializing %d coins\n",
coins_count - coins_left);
return false;
}
if (coin.GetHeight() > uint32_t(base_height) ||
// Avoid integer wrap-around in coinstats.cpp:ApplyHash
outpoint.GetN() >=
std::numeric_limits<decltype(outpoint.GetN())>::max()) {
LogPrintf(
"[snapshot] bad snapshot data after deserializing %d coins\n",
coins_count - coins_left);
return false;
}
coins_cache.EmplaceCoinInternalDANGER(std::move(outpoint),
std::move(coin));
--coins_left;
++coins_processed;
if (coins_processed % 1000000 == 0) {
LogPrintf("[snapshot] %d coins loaded (%.2f%%, %.2f MB)\n",
coins_processed,
static_cast<float>(coins_processed) * 100 /
static_cast<float>(coins_count),
coins_cache.DynamicMemoryUsage() / (1000 * 1000));
}
// Batch write and flush (if we need to) every so often.
//
// If our average Coin size is roughly 41 bytes, checking every 120,000
// coins means <5MB of memory imprecision.
if (coins_processed % 120000 == 0) {
if (ShutdownRequested()) {
return false;
}
const auto snapshot_cache_state = WITH_LOCK(
::cs_main, return snapshot_chainstate.GetCoinsCacheSizeState());
if (snapshot_cache_state >= CoinsCacheSizeState::CRITICAL) {
// This is a hack - we don't know what the actual best block is,
// but that doesn't matter for the purposes of flushing the
// cache here. We'll set this to its correct value
// (`base_blockhash`) below after the coins are loaded.
coins_cache.SetBestBlock(BlockHash{GetRandHash()});
// No need to acquire cs_main since this chainstate isn't being
// used yet.
FlushSnapshotToDisk(coins_cache, /*snapshot_loaded=*/false);
}
}
}
// Important that we set this. This and the coins_cache accesses above are
// sort of a layer violation, but either we reach into the innards of
// CCoinsViewCache here or we have to invert some of the Chainstate to
// embed them in a snapshot-activation-specific CCoinsViewCache bulk load
// method.
coins_cache.SetBestBlock(base_blockhash);
bool out_of_coins{false};
try {
coins_file >> outpoint;
} catch (const std::ios_base::failure &) {
// We expect an exception since we should be out of coins.
out_of_coins = true;
}
if (!out_of_coins) {
LogPrintf("[snapshot] bad snapshot - coins left over after "
"deserializing %d coins\n",
coins_count);
return false;
}
LogPrintf("[snapshot] loaded %d (%.2f MB) coins from snapshot %s\n",
coins_count, coins_cache.DynamicMemoryUsage() / (1000 * 1000),
base_blockhash.ToString());
// No need to acquire cs_main since this chainstate isn't being used yet.
FlushSnapshotToDisk(coins_cache, /*snapshot_loaded=*/true);
assert(coins_cache.GetBestBlock() == base_blockhash);
// As above, okay to immediately release cs_main here since no other context
// knows about the snapshot_chainstate.
CCoinsViewDB *snapshot_coinsdb =
WITH_LOCK(::cs_main, return &snapshot_chainstate.CoinsDB());
std::optional<CCoinsStats> maybe_stats;
try {
maybe_stats = ComputeUTXOStats(CoinStatsHashType::HASH_SERIALIZED,
snapshot_coinsdb, m_blockman,
SnapshotUTXOHashBreakpoint);
} catch (StopHashingException const &) {
return false;
}
if (!maybe_stats.has_value()) {
LogPrintf("[snapshot] failed to generate coins stats\n");
return false;
}
// Assert that the deserialized chainstate contents match the expected
// assumeutxo value.
if (AssumeutxoHash{maybe_stats->hashSerialized} !=
au_data.hash_serialized) {
LogPrintf("[snapshot] bad snapshot content hash: expected %s, got %s\n",
au_data.hash_serialized.ToString(),
maybe_stats->hashSerialized.ToString());
return false;
}
snapshot_chainstate.m_chain.SetTip(*snapshot_start_block);
// The remainder of this function requires modifying data protected by
// cs_main.
LOCK(::cs_main);
// Fake various pieces of CBlockIndex state:
CBlockIndex *index = nullptr;
// Don't make any modifications to the genesis block.
// This is especially important because we don't want to erroneously
// apply ASSUMED_VALID_FLAG to genesis, which would happen if we didn't
// skip it here (since it apparently isn't BlockValidity::SCRIPTS).
constexpr int AFTER_GENESIS_START{1};
for (int i = AFTER_GENESIS_START; i <= snapshot_chainstate.m_chain.Height();
++i) {
index = snapshot_chainstate.m_chain[i];
// Fake nTx so that LoadBlockIndex() loads assumed-valid CBlockIndex
// entries (among other things)
if (!index->nTx) {
index->nTx = 1;
}
// Fake nChainTx so that GuessVerificationProgress reports accurately
index->nChainTx = index->pprev->nChainTx + index->nTx;
// Mark unvalidated block index entries beneath the snapshot base block
// as assumed-valid.
if (!index->IsValid(BlockValidity::SCRIPTS)) {
// This flag will be removed once the block is fully validated by a
// background chainstate.
index->nStatus = index->nStatus.withAssumedValid();
}
m_blockman.m_dirty_blockindex.insert(index);
// Changes to the block index will be flushed to disk after this call
// returns in `ActivateSnapshot()`, when `MaybeRebalanceCaches()` is
// called, since we've added a snapshot chainstate and therefore will
// have to downsize the IBD chainstate, which will result in a call to
// `FlushStateToDisk(ALWAYS)`.
}
assert(index);
index->nChainTx = au_data.nChainTx;
snapshot_chainstate.setBlockIndexCandidates.insert(snapshot_start_block);
LogPrintf("[snapshot] validated snapshot (%.2f MB)\n",
coins_cache.DynamicMemoryUsage() / (1000 * 1000));
return true;
}
// Currently, this function holds cs_main for its duration, which could be for
// multiple minutes due to the ComputeUTXOStats call. This hold is necessary
// because we need to avoid advancing the background validation chainstate
// farther than the snapshot base block - and this function is also invoked
// from within ConnectTip, i.e. from within ActivateBestChain, so cs_main is
// held anyway.
//
// Eventually (TODO), we could somehow separate this function's runtime from
// maintenance of the active chain, but that will either require
//
// (i) setting `m_disabled` immediately and ensuring all chainstate accesses go
// through IsUsable() checks, or
//
// (ii) giving each chainstate its own lock instead of using cs_main for
// everything.
SnapshotCompletionResult ChainstateManager::MaybeCompleteSnapshotValidation(
std::function<void(bilingual_str)> shutdown_fnc) {
AssertLockHeld(cs_main);
if (m_ibd_chainstate.get() == &this->ActiveChainstate() ||
!this->IsUsable(m_snapshot_chainstate.get()) ||
!this->IsUsable(m_ibd_chainstate.get()) ||
!m_ibd_chainstate->m_chain.Tip()) {
// Nothing to do - this function only applies to the background
// validation chainstate.
return SnapshotCompletionResult::SKIPPED;
}
const int snapshot_tip_height = this->ActiveHeight();
const int snapshot_base_height = *Assert(this->GetSnapshotBaseHeight());
const CBlockIndex &index_new = *Assert(m_ibd_chainstate->m_chain.Tip());
if (index_new.nHeight < snapshot_base_height) {
// Background IBD not complete yet.
return SnapshotCompletionResult::SKIPPED;
}
assert(SnapshotBlockhash());
BlockHash snapshot_blockhash = *Assert(SnapshotBlockhash());
auto handle_invalid_snapshot = [&]() EXCLUSIVE_LOCKS_REQUIRED(::cs_main) {
bilingual_str user_error = strprintf(
_("%s failed to validate the -assumeutxo snapshot state. "
"This indicates a hardware problem, or a bug in the software, or "
"a bad software modification that allowed an invalid snapshot to "
"be loaded. As a result of this, the node will shut down and "
"stop using any state that was built on the snapshot, resetting "
"the chain height from %d to %d. On the next restart, the node "
"will resume syncing from %d without using any snapshot data. "
"Please report this incident to %s, including how you obtained "
"the snapshot. The invalid snapshot chainstate will be left on "
"disk in case it is helpful in diagnosing the issue that caused "
"this error."),
PACKAGE_NAME, snapshot_tip_height, snapshot_base_height,
snapshot_base_height, PACKAGE_BUGREPORT);
LogPrintf("[snapshot] !!! %s\n", user_error.original);
LogPrintf("[snapshot] deleting snapshot, reverting to validated chain, "
"and stopping node\n");
m_active_chainstate = m_ibd_chainstate.get();
m_snapshot_chainstate->m_disabled = true;
assert(!this->IsUsable(m_snapshot_chainstate.get()));
assert(this->IsUsable(m_ibd_chainstate.get()));
auto rename_result = m_snapshot_chainstate->InvalidateCoinsDBOnDisk();
if (!rename_result) {
user_error = strprintf(Untranslated("%s\n%s"), user_error,
util::ErrorString(rename_result));
}
shutdown_fnc(user_error);
};
if (index_new.GetBlockHash() != snapshot_blockhash) {
LogPrintf(
"[snapshot] supposed base block %s does not match the "
"snapshot base block %s (height %d). Snapshot is not valid.\n",
index_new.ToString(), snapshot_blockhash.ToString(),
snapshot_base_height);
handle_invalid_snapshot();
return SnapshotCompletionResult::BASE_BLOCKHASH_MISMATCH;
}
assert(index_new.nHeight == snapshot_base_height);
int curr_height = m_ibd_chainstate->m_chain.Height();
assert(snapshot_base_height == curr_height);
assert(snapshot_base_height == index_new.nHeight);
assert(this->IsUsable(m_snapshot_chainstate.get()));
assert(this->GetAll().size() == 2);
CCoinsViewDB &ibd_coins_db = m_ibd_chainstate->CoinsDB();
m_ibd_chainstate->ForceFlushStateToDisk();
auto maybe_au_data = ExpectedAssumeutxo(curr_height, GetParams());
if (!maybe_au_data) {
LogPrintf("[snapshot] assumeutxo data not found for height "
"(%d) - refusing to validate snapshot\n",
curr_height);
handle_invalid_snapshot();
return SnapshotCompletionResult::MISSING_CHAINPARAMS;
}
const AssumeutxoData &au_data = *maybe_au_data;
std::optional<CCoinsStats> maybe_ibd_stats;
LogPrintf(
"[snapshot] computing UTXO stats for background chainstate to validate "
"snapshot - this could take a few minutes\n");
try {
maybe_ibd_stats =
ComputeUTXOStats(CoinStatsHashType::HASH_SERIALIZED, &ibd_coins_db,
m_blockman, SnapshotUTXOHashBreakpoint);
} catch (StopHashingException const &) {
return SnapshotCompletionResult::STATS_FAILED;
}
if (!maybe_ibd_stats) {
LogPrintf(
"[snapshot] failed to generate stats for validation coins db\n");
// While this isn't a problem with the snapshot per se, this condition
// prevents us from validating the snapshot, so we should shut down and
// let the user handle the issue manually.
handle_invalid_snapshot();
return SnapshotCompletionResult::STATS_FAILED;
}
const auto &ibd_stats = *maybe_ibd_stats;
// Compare the background validation chainstate's UTXO set hash against the
// hard-coded assumeutxo hash we expect.
//
// TODO: For belt-and-suspenders, we could cache the UTXO set
// hash for the snapshot when it's loaded in its chainstate's leveldb. We
// could then reference that here for an additional check.
if (AssumeutxoHash{ibd_stats.hashSerialized} != au_data.hash_serialized) {
LogPrintf("[snapshot] hash mismatch: actual=%s, expected=%s\n",
ibd_stats.hashSerialized.ToString(),
au_data.hash_serialized.ToString());
handle_invalid_snapshot();
return SnapshotCompletionResult::HASH_MISMATCH;
}
LogPrintf("[snapshot] snapshot beginning at %s has been fully validated\n",
snapshot_blockhash.ToString());
m_ibd_chainstate->m_disabled = true;
this->MaybeRebalanceCaches();
return SnapshotCompletionResult::SUCCESS;
}
Chainstate &ChainstateManager::ActiveChainstate() const {
LOCK(::cs_main);
assert(m_active_chainstate);
return *m_active_chainstate;
}
bool ChainstateManager::IsSnapshotActive() const {
LOCK(::cs_main);
return m_snapshot_chainstate &&
m_active_chainstate == m_snapshot_chainstate.get();
}
void ChainstateManager::MaybeRebalanceCaches() {
AssertLockHeld(::cs_main);
bool ibd_usable = this->IsUsable(m_ibd_chainstate.get());
bool snapshot_usable = this->IsUsable(m_snapshot_chainstate.get());
assert(ibd_usable || snapshot_usable);
if (ibd_usable && !snapshot_usable) {
LogPrintf("[snapshot] allocating all cache to the IBD chainstate\n");
// Allocate everything to the IBD chainstate.
m_ibd_chainstate->ResizeCoinsCaches(m_total_coinstip_cache,
m_total_coinsdb_cache);
} else if (snapshot_usable && !ibd_usable) {
// If background validation has completed and snapshot is our active
// chain...
LogPrintf(
"[snapshot] allocating all cache to the snapshot chainstate\n");
// Allocate everything to the snapshot chainstate.
m_snapshot_chainstate->ResizeCoinsCaches(m_total_coinstip_cache,
m_total_coinsdb_cache);
} else if (ibd_usable && snapshot_usable) {
// If both chainstates exist, determine who needs more cache based on
// IBD status.
//
// Note: shrink caches first so that we don't inadvertently overwhelm
// available memory.
if (m_snapshot_chainstate->IsInitialBlockDownload()) {
m_ibd_chainstate->ResizeCoinsCaches(m_total_coinstip_cache * 0.05,
m_total_coinsdb_cache * 0.05);
m_snapshot_chainstate->ResizeCoinsCaches(
m_total_coinstip_cache * 0.95, m_total_coinsdb_cache * 0.95);
} else {
m_snapshot_chainstate->ResizeCoinsCaches(
m_total_coinstip_cache * 0.05, m_total_coinsdb_cache * 0.05);
m_ibd_chainstate->ResizeCoinsCaches(m_total_coinstip_cache * 0.95,
m_total_coinsdb_cache * 0.95);
}
}
}
void ChainstateManager::ResetChainstates() {
m_ibd_chainstate.reset();
m_snapshot_chainstate.reset();
m_active_chainstate = nullptr;
}
/**
* Apply default chain params to nullopt members.
* This helps to avoid coding errors around the accidental use of the compare
* operators that accept nullopt, thus ignoring the intended default value.
*/
static ChainstateManager::Options &&Flatten(ChainstateManager::Options &&opts) {
if (!opts.check_block_index.has_value()) {
opts.check_block_index =
opts.config.GetChainParams().DefaultConsistencyChecks();
}
if (!opts.minimum_chain_work.has_value()) {
opts.minimum_chain_work = UintToArith256(
opts.config.GetChainParams().GetConsensus().nMinimumChainWork);
}
if (!opts.assumed_valid_block.has_value()) {
opts.assumed_valid_block =
opts.config.GetChainParams().GetConsensus().defaultAssumeValid;
}
Assert(opts.adjusted_time_callback);
return std::move(opts);
}
ChainstateManager::ChainstateManager(
Options options, node::BlockManager::Options blockman_options)
: m_options{Flatten(std::move(options))}, m_blockman{std::move(
blockman_options)} {}
bool ChainstateManager::DetectSnapshotChainstate(CTxMemPool *mempool) {
assert(!m_snapshot_chainstate);
std::optional<fs::path> path = node::FindSnapshotChainstateDir();
if (!path) {
return false;
}
std::optional<BlockHash> base_blockhash =
node::ReadSnapshotBaseBlockhash(*path);
if (!base_blockhash) {
return false;
}
LogPrintf("[snapshot] detected active snapshot chainstate (%s) - loading\n",
fs::PathToString(*path));
this->ActivateExistingSnapshot(mempool, *base_blockhash);
return true;
}
Chainstate &
ChainstateManager::ActivateExistingSnapshot(CTxMemPool *mempool,
BlockHash base_blockhash) {
assert(!m_snapshot_chainstate);
m_snapshot_chainstate = std::make_unique<Chainstate>(mempool, m_blockman,
*this, base_blockhash);
LogPrintf("[snapshot] switching active chainstate to %s\n",
m_snapshot_chainstate->ToString());
m_active_chainstate = m_snapshot_chainstate.get();
return *m_snapshot_chainstate;
}
util::Result<void> Chainstate::InvalidateCoinsDBOnDisk() {
AssertLockHeld(::cs_main);
// Should never be called on a non-snapshot chainstate.
assert(m_from_snapshot_blockhash);
auto storage_path_maybe = this->CoinsDB().StoragePath();
// Should never be called with a non-existent storage path.
assert(storage_path_maybe);
fs::path snapshot_datadir = *storage_path_maybe;
// Coins views no longer usable.
m_coins_views.reset();
auto invalid_path = snapshot_datadir + "_INVALID";
std::string dbpath = fs::PathToString(snapshot_datadir);
std::string target = fs::PathToString(invalid_path);
LogPrintf("[snapshot] renaming snapshot datadir %s to %s\n", dbpath,
target);
// The invalid snapshot datadir is simply moved and not deleted because we
// may want to do forensics later during issue investigation. The user is
// instructed accordingly in MaybeCompleteSnapshotValidation().
try {
fs::rename(snapshot_datadir, invalid_path);
} catch (const fs::filesystem_error &e) {
auto src_str = fs::PathToString(snapshot_datadir);
auto dest_str = fs::PathToString(invalid_path);
LogPrintf("%s: error renaming file '%s' -> '%s': %s\n", __func__,
src_str, dest_str, e.what());
return util::Error{strprintf(_("Rename of '%s' -> '%s' failed. "
"You should resolve this by manually "
"moving or deleting the invalid "
"snapshot directory %s, otherwise you "
"will encounter the same error again "
"on the next startup."),
src_str, dest_str, src_str)};
}
return {};
}
const CBlockIndex *ChainstateManager::GetSnapshotBaseBlock() const {
const auto blockhash_op = this->SnapshotBlockhash();
if (!blockhash_op) {
return nullptr;
}
return Assert(m_blockman.LookupBlockIndex(*blockhash_op));
}
std::optional<int> ChainstateManager::GetSnapshotBaseHeight() const {
const CBlockIndex *base = this->GetSnapshotBaseBlock();
return base ? std::make_optional(base->nHeight) : std::nullopt;
}
bool ChainstateManager::ValidatedSnapshotCleanup() {
AssertLockHeld(::cs_main);
auto get_storage_path = [](auto &chainstate) EXCLUSIVE_LOCKS_REQUIRED(
::cs_main) -> std::optional<fs::path> {
if (!(chainstate && chainstate->HasCoinsViews())) {
return {};
}
return chainstate->CoinsDB().StoragePath();
};
std::optional<fs::path> ibd_chainstate_path_maybe =
get_storage_path(m_ibd_chainstate);
std::optional<fs::path> snapshot_chainstate_path_maybe =
get_storage_path(m_snapshot_chainstate);
if (!this->IsSnapshotValidated()) {
// No need to clean up.
return false;
}
// If either path doesn't exist, that means at least one of the chainstates
// is in-memory, in which case we can't do on-disk cleanup. You'd better be
// in a unittest!
if (!ibd_chainstate_path_maybe || !snapshot_chainstate_path_maybe) {
LogPrintf("[snapshot] snapshot chainstate cleanup cannot happen with "
"in-memory chainstates. You are testing, right?\n");
return false;
}
const auto &snapshot_chainstate_path = *snapshot_chainstate_path_maybe;
const auto &ibd_chainstate_path = *ibd_chainstate_path_maybe;
// Since we're going to be moving around the underlying leveldb filesystem
// content for each chainstate, make sure that the chainstates (and their
// constituent CoinsViews members) have been destructed first.
//
// The caller of this method will be responsible for reinitializing
// chainstates if they want to continue operation.
this->ResetChainstates();
// No chainstates should be considered usable.
assert(this->GetAll().size() == 0);
LogPrintf("[snapshot] deleting background chainstate directory (now "
"unnecessary) (%s)\n",
fs::PathToString(ibd_chainstate_path));
fs::path tmp_old{ibd_chainstate_path + "_todelete"};
auto rename_failed_abort = [](fs::path p_old, fs::path p_new,
const fs::filesystem_error &err) {
LogPrintf("Error renaming file (%s): %s\n", fs::PathToString(p_old),
err.what());
AbortNode(strprintf(
"Rename of '%s' -> '%s' failed. "
"Cannot clean up the background chainstate leveldb directory.",
fs::PathToString(p_old), fs::PathToString(p_new)));
};
try {
fs::rename(ibd_chainstate_path, tmp_old);
} catch (const fs::filesystem_error &e) {
rename_failed_abort(ibd_chainstate_path, tmp_old, e);
throw;
}
LogPrintf("[snapshot] moving snapshot chainstate (%s) to "
"default chainstate directory (%s)\n",
fs::PathToString(snapshot_chainstate_path),
fs::PathToString(ibd_chainstate_path));
try {
fs::rename(snapshot_chainstate_path, ibd_chainstate_path);
} catch (const fs::filesystem_error &e) {
rename_failed_abort(snapshot_chainstate_path, ibd_chainstate_path, e);
throw;
}
if (!DeleteCoinsDBFromDisk(tmp_old, /*is_snapshot=*/false)) {
// No need to AbortNode because once the unneeded bg chainstate data is
// moved, it will not interfere with subsequent initialization.
LogPrintf("Deletion of %s failed. Please remove it manually, as the "
"directory is now unnecessary.\n",
fs::PathToString(tmp_old));
} else {
LogPrintf("[snapshot] deleted background chainstate directory (%s)\n",
fs::PathToString(ibd_chainstate_path));
}
return true;
}