diff --git a/src/seeder/dns.cpp b/src/seeder/dns.cpp
index 63641d7c1..0bca7171f 100644
--- a/src/seeder/dns.cpp
+++ b/src/seeder/dns.cpp
@@ -1,609 +1,605 @@
 #include <seeder/dns.h>
 
 #include <arpa/inet.h>
 #include <netinet/in.h>
 #include <strings.h>
 #include <sys/socket.h>
 #include <sys/types.h>
 #include <unistd.h>
 
 #include <cctype>
 #include <cstdbool>
 #include <cstdio>
 #include <cstdlib>
 #include <cstring>
 #include <ctime>
 
 #define BUFLEN 512
 
 #if defined IP_RECVDSTADDR
 #define DSTADDR_SOCKOPT IP_RECVDSTADDR
 #define DSTADDR_DATASIZE (CMSG_SPACE(sizeof(struct in6_addr)))
 #define dstaddr(x) (CMSG_DATA(x))
 #elif defined IPV6_PKTINFO
 #define DSTADDR_SOCKOPT IPV6_PKTINFO
 #define DSTADDR_DATASIZE (CMSG_SPACE(sizeof(struct in6_pktinfo)))
 #define dstaddr(x) (&(((struct in6_pktinfo *)(CMSG_DATA(x)))->ipi6_addr))
 #else
 #error "can't determine socket option"
 #endif
 
 union control_data {
     struct cmsghdr cmsg;
     uint8_t data[DSTADDR_DATASIZE];
 };
 
 typedef enum { CLASS_IN = 1, QCLASS_ANY = 255 } dns_class;
 
 typedef enum {
     TYPE_A = 1,
     TYPE_NS = 2,
     TYPE_CNAME = 5,
     TYPE_SOA = 6,
     TYPE_MX = 15,
     TYPE_AAAA = 28,
     TYPE_SRV = 33,
     QTYPE_ANY = 255
 } dns_type;
 
-//  0: ok
-// -1: premature end of input, forward reference, component > 63 char, invalid
-// character
-// -2: insufficient space in output
-static int parse_name(const uint8_t **inpos, const uint8_t *inend,
-                      const uint8_t *inbuf, char *buf, size_t bufsize) {
+int parse_name(const uint8_t **inpos, const uint8_t *inend,
+               const uint8_t *inbuf, char *buf, size_t bufsize) {
     size_t bufused = 0;
     int init = 1;
     do {
         if (*inpos == inend) return -1;
         // read length of next component
         int octet = *((*inpos)++);
         if (octet == 0) {
             buf[bufused] = 0;
             return 0;
         }
         // add dot in output
         if (!init) {
             if (bufused == bufsize - 1) return -2;
             buf[bufused++] = '.';
         } else
             init = 0;
         // handle references
         if ((octet & 0xC0) == 0xC0) {
             if (*inpos == inend) return -1;
             int ref = ((octet - 0xC0) << 8) + *((*inpos)++);
             if (ref < 0 || ref >= (*inpos) - inbuf - 2) return -1;
             const uint8_t *newbuf = inbuf + ref;
             return parse_name(&newbuf, (*inpos) - 2, inbuf, buf + bufused,
                               bufsize - bufused);
         }
         if (octet > 63) return -1;
         // copy label
         while (octet) {
             if (*inpos == inend) return -1;
             if (bufused == bufsize - 1) return -2;
             int c = *((*inpos)++);
             if (c == '.') return -1;
             octet--;
             buf[bufused++] = c;
         }
     } while (1);
 }
 
 //  0: k
 // -1: component > 63 characters
 // -2: insufficent space in output
 // -3: two subsequent dots
 static int write_name(uint8_t **outpos, const uint8_t *outend, const char *name,
                       int offset) {
     while (*name != 0) {
         const char *dot = strchr(name, '.');
         const char *fin = dot;
         if (!dot) fin = name + strlen(name);
         if (fin - name > 63) return -1;
         if (fin == name) return -3;
         if (outend - *outpos < fin - name + 2) return -2;
         *((*outpos)++) = fin - name;
         memcpy(*outpos, name, fin - name);
         *outpos += fin - name;
         if (!dot) break;
         name = dot + 1;
     }
     if (offset < 0) {
         // no reference
         if (outend == *outpos) return -2;
         *((*outpos)++) = 0;
     } else {
         if (outend - *outpos < 2) return -2;
         *((*outpos)++) = (offset >> 8) | 0xC0;
         *((*outpos)++) = offset & 0xFF;
     }
     return 0;
 }
 
 static int write_record(uint8_t **outpos, const uint8_t *outend,
                         const char *name, int offset, dns_type typ,
                         dns_class cls, int ttl) {
     uint8_t *oldpos = *outpos;
     int error = 0;
     // name
     int ret = write_name(outpos, outend, name, offset);
     if (ret) {
         error = ret;
         goto error;
     }
     if (outend - *outpos < 8) {
         error = -4;
         goto error;
     }
     // type
     *((*outpos)++) = typ >> 8;
     *((*outpos)++) = typ & 0xFF;
     // class
     *((*outpos)++) = cls >> 8;
     *((*outpos)++) = cls & 0xFF;
     // ttl
     *((*outpos)++) = (ttl >> 24) & 0xFF;
     *((*outpos)++) = (ttl >> 16) & 0xFF;
     *((*outpos)++) = (ttl >> 8) & 0xFF;
     *((*outpos)++) = ttl & 0xFF;
     return 0;
 error:
     *outpos = oldpos;
     return error;
 }
 
 static int write_record_a(uint8_t **outpos, const uint8_t *outend,
                           const char *name, int offset, dns_class cls, int ttl,
                           const addr_t *ip) {
     if (ip->v != 4) return -6;
     uint8_t *oldpos = *outpos;
     int error = 0;
     int ret = write_record(outpos, outend, name, offset, TYPE_A, cls, ttl);
     if (ret) return ret;
     if (outend - *outpos < 6) {
         error = -5;
         goto error;
     }
     // rdlength
     *((*outpos)++) = 0;
     *((*outpos)++) = 4;
     // rdata
     for (int i = 0; i < 4; i++)
         *((*outpos)++) = ip->data.v4[i];
     return 0;
 error:
     *outpos = oldpos;
     return error;
 }
 
 static int write_record_aaaa(uint8_t **outpos, const uint8_t *outend,
                              const char *name, int offset, dns_class cls,
                              int ttl, const addr_t *ip) {
     if (ip->v != 6) return -6;
     uint8_t *oldpos = *outpos;
     int error = 0;
     int ret = write_record(outpos, outend, name, offset, TYPE_AAAA, cls, ttl);
     if (ret) return ret;
     if (outend - *outpos < 6) {
         error = -5;
         goto error;
     }
     // rdlength
     *((*outpos)++) = 0;
     *((*outpos)++) = 16;
     // rdata
     for (int i = 0; i < 16; i++)
         *((*outpos)++) = ip->data.v6[i];
     return 0;
 error:
     *outpos = oldpos;
     return error;
 }
 
 static int write_record_ns(uint8_t **outpos, const uint8_t *outend,
                            const char *name, int offset, dns_class cls, int ttl,
                            const char *ns) {
     uint8_t *oldpos = *outpos;
     int ret = write_record(outpos, outend, name, offset, TYPE_NS, cls, ttl);
     if (ret) {
         return ret;
     }
 
     // Predeclare to avoid jumping over declaration.
     uint8_t *curpos;
 
     int error = 0;
     if (outend - *outpos < 2) {
         error = -5;
         goto error;
     }
 
     (*outpos) += 2;
     curpos = *outpos;
     ret = write_name(outpos, outend, ns, -1);
     if (ret) {
         error = ret;
         goto error;
     }
 
     curpos[-2] = (*outpos - curpos) >> 8;
     curpos[-1] = (*outpos - curpos) & 0xFF;
     return 0;
 
 error:
     *outpos = oldpos;
     return error;
 }
 
 static int write_record_soa(uint8_t **outpos, const uint8_t *outend,
                             const char *name, int offset, dns_class cls,
                             int ttl, const char *mname, const char *rname,
                             uint32_t serial, uint32_t refresh, uint32_t retry,
                             uint32_t expire, uint32_t minimum) {
     uint8_t *oldpos = *outpos;
     int ret = write_record(outpos, outend, name, offset, TYPE_SOA, cls, ttl);
     if (ret) {
         return ret;
     }
 
     // Predeclare variable to not jump over declarations.
     uint8_t *curpos;
 
     int error = 0;
     if (outend - *outpos < 2) {
         error = -5;
         goto error;
     }
 
     (*outpos) += 2;
     curpos = *outpos;
     ret = write_name(outpos, outend, mname, -1);
     if (ret) {
         error = ret;
         goto error;
     }
 
     ret = write_name(outpos, outend, rname, -1);
     if (ret) {
         error = ret;
         goto error;
     }
 
     if (outend - *outpos < 20) {
         error = -5;
         goto error;
     }
 
     *((*outpos)++) = (serial >> 24) & 0xFF;
     *((*outpos)++) = (serial >> 16) & 0xFF;
     *((*outpos)++) = (serial >> 8) & 0xFF;
     *((*outpos)++) = serial & 0xFF;
     *((*outpos)++) = (refresh >> 24) & 0xFF;
     *((*outpos)++) = (refresh >> 16) & 0xFF;
     *((*outpos)++) = (refresh >> 8) & 0xFF;
     *((*outpos)++) = refresh & 0xFF;
     *((*outpos)++) = (retry >> 24) & 0xFF;
     *((*outpos)++) = (retry >> 16) & 0xFF;
     *((*outpos)++) = (retry >> 8) & 0xFF;
     *((*outpos)++) = retry & 0xFF;
     *((*outpos)++) = (expire >> 24) & 0xFF;
     *((*outpos)++) = (expire >> 16) & 0xFF;
     *((*outpos)++) = (expire >> 8) & 0xFF;
     *((*outpos)++) = expire & 0xFF;
     *((*outpos)++) = (minimum >> 24) & 0xFF;
     *((*outpos)++) = (minimum >> 16) & 0xFF;
     *((*outpos)++) = (minimum >> 8) & 0xFF;
     *((*outpos)++) = minimum & 0xFF;
     curpos[-2] = (*outpos - curpos) >> 8;
     curpos[-1] = (*outpos - curpos) & 0xFF;
     return 0;
 
 error:
     *outpos = oldpos;
     return error;
 }
 
 static ssize_t dnshandle(dns_opt_t *opt, const uint8_t *inbuf, size_t insize,
                          uint8_t *outbuf) {
     int error = 0;
     if (insize < 12) {
         // DNS header
         return -1;
     }
 
     // Predeclare various variables to avoid jumping over declarations.
     int have_ns = 0;
     int max_auth_size = 0;
     int nquestion = 0;
 
     // copy id
     outbuf[0] = inbuf[0];
     outbuf[1] = inbuf[1];
     // copy flags;
     outbuf[2] = inbuf[2];
     outbuf[3] = inbuf[3];
     // clear error
     outbuf[3] &= ~15;
     // check qr
     if (inbuf[2] & 128) {
         /* fprintf(stdout, "Got response?\n"); */
         error = 1;
         goto error;
     }
 
     // check opcode
     if (((inbuf[2] & 120) >> 3) != 0) {
         /* fprintf(stdout, "Opcode nonzero?\n"); */
         error = 4;
         goto error;
     }
 
     // unset TC
     outbuf[2] &= ~2;
     // unset RA
     outbuf[3] &= ~128;
     // check questions
     nquestion = (inbuf[4] << 8) + inbuf[5];
     if (nquestion == 0) {
         /* fprintf(stdout, "No questions?\n"); */
         error = 0;
         goto error;
     }
 
     if (nquestion > 1) {
         /* fprintf(stdout, "Multiple questions %i?\n", nquestion); */
         error = 4;
         goto error;
     }
 
     {
         const uint8_t *inpos = inbuf + 12;
         const uint8_t *inend = inbuf + insize;
         char name[256];
         int offset = inpos - inbuf;
         int ret = parse_name(&inpos, inend, inbuf, name, 256);
         if (ret == -1) {
             error = 1;
             goto error;
         }
 
         if (ret == -2) {
             error = 5;
             goto error;
         }
 
         int namel = strlen(name), hostl = strlen(opt->host);
         if (strcasecmp(name, opt->host) &&
             (namel < hostl + 2 || name[namel - hostl - 1] != '.' ||
              strcasecmp(name + namel - hostl, opt->host))) {
             error = 5;
             goto error;
         }
 
         if (inend - inpos < 4) {
             error = 1;
             goto error;
         }
 
         // copy question to output
         memcpy(outbuf + 12, inbuf + 12, inpos + 4 - (inbuf + 12));
         // set counts
         outbuf[4] = 0;
         outbuf[5] = 1;
         outbuf[6] = 0;
         outbuf[7] = 0;
         outbuf[8] = 0;
         outbuf[9] = 0;
         outbuf[10] = 0;
         outbuf[11] = 0;
         // set qr
         outbuf[2] |= 128;
 
         int typ = (inpos[0] << 8) + inpos[1];
         int cls = (inpos[2] << 8) + inpos[3];
         inpos += 4;
 
         uint8_t *outpos = outbuf + (inpos - inbuf);
         uint8_t *outend = outbuf + BUFLEN;
 
         //   fprintf(stdout, "DNS: Request host='%s' type=%i class=%i\n", name,
         //   typ, cls);
 
         // calculate max size of authority section
 
         if (!((typ == TYPE_NS || typ == QTYPE_ANY) &&
               (cls == CLASS_IN || cls == QCLASS_ANY))) {
             // authority section will be necessary, either NS or SOA
             uint8_t *newpos = outpos;
             write_record_ns(&newpos, outend, "", offset, CLASS_IN, 0, opt->ns);
             max_auth_size = newpos - outpos;
 
             newpos = outpos;
             write_record_soa(&newpos, outend, "", offset, CLASS_IN, opt->nsttl,
                              opt->ns, opt->mbox, time(NULL), 604800, 86400,
                              2592000, 604800);
             if (max_auth_size < newpos - outpos)
                 max_auth_size = newpos - outpos;
             //    fprintf(stdout, "Authority section will claim %i bytes max\n",
             //    max_auth_size);
         }
 
         // Answer section
 
         // NS records
         if ((typ == TYPE_NS || typ == QTYPE_ANY) &&
             (cls == CLASS_IN || cls == QCLASS_ANY)) {
             int ret2 = write_record_ns(&outpos, outend - max_auth_size, "",
                                        offset, CLASS_IN, opt->nsttl, opt->ns);
             //    fprintf(stdout, "wrote NS record: %i\n", ret2);
             if (!ret2) {
                 outbuf[7]++;
                 have_ns++;
             }
         }
 
         // SOA records
         if ((typ == TYPE_SOA || typ == QTYPE_ANY) &&
             (cls == CLASS_IN || cls == QCLASS_ANY) && opt->mbox) {
             int ret2 =
                 write_record_soa(&outpos, outend - max_auth_size, "", offset,
                                  CLASS_IN, opt->nsttl, opt->ns, opt->mbox,
                                  time(NULL), 604800, 86400, 2592000, 604800);
             //    fprintf(stdout, "wrote SOA record: %i\n", ret2);
             if (!ret2) {
                 outbuf[7]++;
             }
         }
 
         // A/AAAA records
         if ((typ == TYPE_A || typ == TYPE_AAAA || typ == QTYPE_ANY) &&
             (cls == CLASS_IN || cls == QCLASS_ANY)) {
             addr_t addr[32];
             int naddr = opt->cb((void *)opt, name, addr, 32,
                                 typ == TYPE_A || typ == QTYPE_ANY,
                                 typ == TYPE_AAAA || typ == QTYPE_ANY);
             int n = 0;
             while (n < naddr) {
                 int mustbreak = 1;
                 if (addr[n].v == 4) {
                     mustbreak = write_record_a(&outpos, outend - max_auth_size,
                                                "", offset, CLASS_IN,
                                                opt->datattl, &addr[n]);
                 } else if (addr[n].v == 6) {
                     mustbreak = write_record_aaaa(
                         &outpos, outend - max_auth_size, "", offset, CLASS_IN,
                         opt->datattl, &addr[n]);
                 }
 
                 //      fprintf(stdout, "wrote A record: %i\n", mustbreak);
                 if (mustbreak) {
                     break;
                 }
 
                 n++;
                 outbuf[7]++;
             }
         }
 
         // Authority section
         if (!have_ns && outbuf[7]) {
             int ret2 = write_record_ns(&outpos, outend, "", offset, CLASS_IN,
                                        opt->nsttl, opt->ns);
             //    fprintf(stdout, "wrote NS record: %i\n", ret2);
             if (!ret2) {
                 outbuf[9]++;
             }
         } else if (!outbuf[7]) {
             // Didn't include any answers, so reply with SOA as this is a
             // negative response. If we replied with NS above we'd create a bad
             // horizontal referral loop, as the NS response indicates where the
             // resolver should try next.
             int ret2 = write_record_soa(
                 &outpos, outend, "", offset, CLASS_IN, opt->nsttl, opt->ns,
                 opt->mbox, time(NULL), 604800, 86400, 2592000, 604800);
             //    fprintf(stdout, "wrote SOA record: %i\n", ret2);
             if (!ret2) {
                 outbuf[9]++;
             }
         }
 
         // set AA
         outbuf[2] |= 4;
 
         return outpos - outbuf;
     }
 
 error:
     // set error
     outbuf[3] |= error & 0xF;
     // set counts
     outbuf[4] = 0;
     outbuf[5] = 0;
     outbuf[6] = 0;
     outbuf[7] = 0;
     outbuf[8] = 0;
     outbuf[9] = 0;
     outbuf[10] = 0;
     outbuf[11] = 0;
     return 12;
 }
 
 static int listenSocket = -1;
 
 int dnsserver(dns_opt_t *opt) {
     struct sockaddr_in6 si_other;
     int senderSocket = -1;
     senderSocket = socket(AF_INET6, SOCK_DGRAM, IPPROTO_UDP);
     if (senderSocket == -1) return -3;
 
     int replySocket;
     if (listenSocket == -1) {
         struct sockaddr_in6 si_me;
         if ((listenSocket = socket(AF_INET6, SOCK_DGRAM, IPPROTO_UDP)) == -1) {
             listenSocket = -1;
             return -1;
         }
         replySocket = socket(AF_INET6, SOCK_DGRAM, IPPROTO_UDP);
         if (replySocket == -1) {
             close(listenSocket);
             return -1;
         }
         int sockopt = 1;
         setsockopt(listenSocket, IPPROTO_IPV6, DSTADDR_SOCKOPT, &sockopt,
                    sizeof sockopt);
         memset((char *)&si_me, 0, sizeof(si_me));
         si_me.sin6_family = AF_INET6;
         si_me.sin6_port = htons(opt->port);
         si_me.sin6_addr = in6addr_any;
         if (bind(listenSocket, (struct sockaddr *)&si_me, sizeof(si_me)) == -1)
             return -2;
     }
 
     uint8_t inbuf[BUFLEN], outbuf[BUFLEN];
     struct iovec iov[1] = {
         {
             .iov_base = inbuf,
             .iov_len = sizeof(inbuf),
         },
     };
 
     union control_data cmsg;
     msghdr msg;
     msg.msg_name = &si_other;
     msg.msg_namelen = sizeof(si_other);
     msg.msg_iov = iov;
     msg.msg_iovlen = 1;
     msg.msg_control = &cmsg;
     msg.msg_controllen = sizeof(cmsg);
 
     for (; 1; ++(opt->nRequests)) {
         ssize_t insize = recvmsg(listenSocket, &msg, 0);
         //    uint8_t *addr = (uint8_t*)&si_other.sin_addr.s_addr;
         //    fprintf(stdout, "DNS: Request %llu from %i.%i.%i.%i:%i of %i
         //    bytes\n", (unsigned long long)(opt->nRequests), addr[0], addr[1],
         //    addr[2], addr[3], ntohs(si_other.sin_port), (int)insize);
         if (insize <= 0) continue;
 
         ssize_t ret = dnshandle(opt, inbuf, insize, outbuf);
         if (ret <= 0) continue;
 
         bool handled = false;
         for (struct cmsghdr *hdr = CMSG_FIRSTHDR(&msg); hdr;
              hdr = CMSG_NXTHDR(&msg, hdr)) {
             if (hdr->cmsg_level == IPPROTO_IP &&
                 hdr->cmsg_type == DSTADDR_SOCKOPT) {
                 msg.msg_iov[0].iov_base = outbuf;
                 msg.msg_iov[0].iov_len = ret;
                 sendmsg(listenSocket, &msg, 0);
                 msg.msg_iov[0].iov_base = inbuf;
                 msg.msg_iov[0].iov_len = sizeof(inbuf);
                 handled = true;
             }
         }
         if (!handled)
             sendto(listenSocket, outbuf, ret, 0, (struct sockaddr *)&si_other,
                    sizeof(si_other));
     }
     return 0;
 }
diff --git a/src/seeder/dns.h b/src/seeder/dns.h
index 34e56db3e..cb578bb8e 100644
--- a/src/seeder/dns.h
+++ b/src/seeder/dns.h
@@ -1,29 +1,37 @@
 #ifndef BITCOIN_SEEDER_DNS_H
 #define BITCOIN_SEEDER_DNS_H 1
 
+#include <cstddef>
 #include <cstdint>
 
 struct addr_t {
     int v;
     union {
         uint8_t v4[4];
         uint8_t v6[16];
     } data;
 };
 
 struct dns_opt_t {
     int port;
     int datattl;
     int nsttl;
     const char *host;
     const char *ns;
     const char *mbox;
     uint32_t (*cb)(void *opt, char *requested_hostname, addr_t *addr,
                    uint32_t max, uint32_t ipv4, uint32_t ipv6);
     // stats
     uint64_t nRequests;
 };
 
+//  0: ok
+// -1: premature end of input, forward reference, component > 63 char, invalid
+// character
+// -2: insufficient space in output
+int parse_name(const uint8_t **inpos, const uint8_t *inend,
+               const uint8_t *inbuf, char *buf, size_t bufsize);
+
 int dnsserver(dns_opt_t *opt);
 
 #endif // BITCOIN_SEEDER_DNS_H