pdns/ixfrutils.cc

   1 /*
   2  * This file is part of PowerDNS or dnsdist.
   3  * Copyright -- PowerDNS.COM B.V. and its contributors
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of version 2 of the GNU General Public License as
   7  * published by the Free Software Foundation.
   8  *
   9  * In addition, for the avoidance of any doubt, permission is granted to
  10  * link this program with OpenSSL and to (re)distribute the binaries
  11  * produced as the result of such linking.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  21  */
  22
  23 #include <cinttypes>
  24 #include <dirent.h>
  25 #include <errno.h>
  26 #include "ixfrutils.hh"
  27 #include "sstuff.hh"
  28 #include "dnssecinfra.hh"
  29 #include "zoneparser-tng.hh"
  30 #include "dnsparser.hh"
  31
  32 uint32_t getSerialFromMaster(const ComboAddress& master, const DNSName& zone, shared_ptr<SOARecordContent>& sr, const TSIGTriplet& tt, const uint16_t timeout)
  33 {
  34   vector<uint8_t> packet;
  35   DNSPacketWriter pw(packet, zone, QType::SOA);
  36   if(!tt.algo.empty()) {
  37     TSIGRecordContent trc;
  38     trc.d_algoName = tt.algo;
  39     trc.d_time = time(nullptr);
  40     trc.d_fudge = 300;
  41     trc.d_origID=ntohs(pw.getHeader()->id);
  42     trc.d_eRcode=0;
  43     addTSIG(pw, trc, tt.name, tt.secret, "", false);
  44   }
  45
  46   Socket s(master.sin4.sin_family, SOCK_DGRAM);
  47   s.connect(master);
  48   string msg((const char*)&packet[0], packet.size());
  49   s.writen(msg);
  50
  51   string reply;
  52   reply.resize(4096);
  53   // will throw a NetworkError on timeout
  54   ssize_t got = s.readWithTimeout(&reply[0], reply.size(), timeout);
  55   if (got < 0 || static_cast<size_t>(got) < sizeof(dnsheader)) {
  56     throw std::runtime_error("Invalid response size " + std::to_string(got));
  57   }
  58
  59   reply.resize(got);
  60
  61   MOADNSParser mdp(false, reply);
  62   if(mdp.d_header.rcode) {
  63     throw std::runtime_error("RCODE from response is not NoError but " + RCode::to_s(mdp.d_header.rcode));
  64   }
  65   for(const auto& r: mdp.d_answers) {
  66     if(r.first.d_type == QType::SOA) {
  67       sr = getRR<SOARecordContent>(r.first);
  68       if(sr != nullptr) {
  69         return sr->d_st.serial;
  70       }
  71     }
  72   }
  73   return 0;
  74 }
  75
  76 uint32_t getSerialsFromDir(const std::string& dir)
  77 {
  78   uint32_t ret=0;
  79   DIR* dirhdl=opendir(dir.c_str());
  80   if(!dirhdl)
  81     throw runtime_error("Could not open IXFR directory '" + dir + "': " + strerror(errno));
  82   struct dirent *entry;
  83
  84   while((entry = readdir(dirhdl))) {
  85     uint32_t num = atoi(entry->d_name);
  86     if(std::to_string(num) == entry->d_name)
  87       ret = max(num, ret);
  88   }
  89   closedir(dirhdl);
  90   return ret;
  91 }
  92
  93 uint32_t getSerialFromRecords(const records_t& records, DNSRecord& soaret)
  94 {
  95   DNSName root(".");
  96   uint16_t t=QType::SOA;
  97
  98   auto found = records.equal_range(tie(root, t));
  99
 100   for(auto iter = found.first; iter != found.second; ++iter) {
 101     auto soa = std::dynamic_pointer_cast<SOARecordContent>(iter->d_content);
 102     if (soa) {
 103       soaret = *iter;
 104       return soa->d_st.serial;
 105     }
 106   }
 107   return 0;
 108 }
 109
 110 static void writeRecords(FILE* fp, const records_t& records)
 111 {
 112   for(const auto& r: records) {
 113     fprintf(fp, "%s\t%" PRIu32 "\tIN\t%s\t%s\n",
 114             r.d_name.isRoot() ? "@" :  r.d_name.toStringNoDot().c_str(),
 115             r.d_ttl,
 116             DNSRecordContent::NumberToType(r.d_type).c_str(),
 117             r.d_content->getZoneRepresentation().c_str());
 118   }
 119 }
 120
 121 void writeZoneToDisk(const records_t& records, const DNSName& zone, const std::string& directory)
 122 {
 123   DNSRecord soa;
 124   auto serial = getSerialFromRecords(records, soa);
 125   string fname=directory +"/"+std::to_string(serial);
 126   FILE* fp=fopen((fname+".partial").c_str(), "w");
 127   if(!fp)
 128     throw runtime_error("Unable to open file '"+fname+".partial' for writing: "+string(strerror(errno)));
 129
 130   records_t soarecord;
 131   soarecord.insert(soa);
 132   fprintf(fp, "$ORIGIN %s\n", zone.toString().c_str());
 133
 134   writeRecords(fp, soarecord);
 135   writeRecords(fp, records);
 136   writeRecords(fp, soarecord);
 137
 138   fclose(fp);
 139   if (rename( (fname+".partial").c_str(), fname.c_str()) != 0) {
 140     throw std::runtime_error("Unable to move the zone file for " + zone.toLogString() + " from " + fname + ".partial to " + fname + ": " + string(strerror(errno)));
 141   }
 142 }
 143
 144 void loadZoneFromDisk(records_t& records, const string& fname, const DNSName& zone)
 145 {
 146   ZoneParserTNG zpt(fname, zone);
 147
 148   DNSResourceRecord rr;
 149   bool seenSOA=false;
 150   while(zpt.get(rr)) {
 151     if(rr.qtype.getCode() == QType::CNAME && rr.content.empty())
 152       rr.content=".";
 153     rr.qname = rr.qname.makeRelative(zone);
 154
 155     if(rr.qtype.getCode() != QType::SOA || seenSOA==false)
 156       records.insert(DNSRecord(rr));
 157     if(rr.qtype.getCode() == QType::SOA) {
 158       seenSOA=true;
 159     }
 160   }
 161   if(!(rr.qtype.getCode() == QType::SOA && seenSOA)) {
 162     records.clear();
 163     throw runtime_error("Zone not complete!");
 164   }
 165 }
 166
 167 /*
 168  * Load the zone `zone` from `fname` and put the first found SOA into `soa`
 169  * Does NOT check for nullptr
 170  */
 171 void loadSOAFromDisk(const DNSName& zone, const string& fname, shared_ptr<SOARecordContent>& soa, uint32_t& soaTTL)
 172 {
 173   ZoneParserTNG zpt(fname, zone);
 174   DNSResourceRecord rr;
 175
 176   while(zpt.get(rr)) {
 177     if (rr.qtype == QType::SOA) {
 178       soa = getRR<SOARecordContent>(DNSRecord(rr));
 179       soaTTL = rr.ttl;
 180       return;
 181     }
 182   }
 183 }