src/modules/m_spanningtree/resolvers.cpp

   1 /*
   2  * InspIRCd -- Internet Relay Chat Daemon
   3  *
   4  *   Copyright (C) 2013, 2019 Sadie Powell <sadie@witchery.services>
   5  *   Copyright (C) 2013, 2016 Adam <Adam@anope.org>
   6  *   Copyright (C) 2012-2014, 2016 Attila Molnar <attilamolnar@hush.com>
   7  *   Copyright (C) 2012 Robby <robby@chatbelgie.be>
   8  *   Copyright (C) 2009 Daniel De Graaf <danieldg@inspircd.org>
   9  *   Copyright (C) 2007, 2010 Craig Edwards <brain@inspircd.org>
  10  *   Copyright (C) 2007 Robin Burchell <robin+git@viroteck.net>
  11  *   Copyright (C) 2007 Dennis Friis <peavey@inspircd.org>
  12  *
  13  * This file is part of InspIRCd.  InspIRCd is free software: you can
  14  * redistribute it and/or modify it under the terms of the GNU General Public
  15  * License as published by the Free Software Foundation, version 2.
  16  *
  17  * This program is distributed in the hope that it will be useful, but WITHOUT
  18  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  19  * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
  20  * details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  24  */
  25
  26
  27 #include "inspircd.h"
  28
  29 #include "cachetimer.h"
  30 #include "resolvers.h"
  31 #include "main.h"
  32 #include "utils.h"
  33 #include "treeserver.h"
  34 #include "link.h"
  35 #include "treesocket.h"
  36
  37 /** This class is used to resolve server hostnames during /connect and autoconnect.
  38  * As of 1.1, the resolver system is seperated out from BufferedSocket, so we must do this
  39  * resolver step first ourselves if we need it. This is totally nonblocking, and will
  40  * callback to OnLookupComplete or OnError when completed. Once it has completed we
  41  * will have an IP address which we can then use to continue our connection.
  42  */
  43 ServernameResolver::ServernameResolver(DNS::Manager* mgr, const std::string& hostname, Link* x, DNS::QueryType qt, Autoconnect* myac)
  44         : DNS::Request(mgr, Utils->Creator, hostname, qt)
  45         , query(qt), host(hostname), MyLink(x), myautoconnect(myac)
  46 {
  47 }
  48
  49 void ServernameResolver::OnLookupComplete(const DNS::Query *r)
  50 {
  51         const DNS::ResourceRecord* const ans_record = r->FindAnswerOfType(this->question.type);
  52         if (!ans_record)
  53         {
  54                 OnError(r);
  55                 return;
  56         }
  57
  58         irc::sockets::sockaddrs sa;
  59         if (!irc::sockets::aptosa(ans_record->rdata, MyLink->Port, sa))
  60         {
  61                 // We had a result but it wasn't a valid IPv4/IPv6.
  62                 OnError(r);
  63                 return;
  64         }
  65
  66         /* Initiate the connection, now that we have an IP to use.
  67          * Passing a hostname directly to BufferedSocket causes it to
  68          * just bail and set its FD to -1.
  69          */
  70         TreeServer* CheckDupe = Utils->FindServer(MyLink->Name);
  71         if (!CheckDupe) /* Check that nobody tried to connect it successfully while we were resolving */
  72         {
  73                 TreeSocket* newsocket = new TreeSocket(MyLink, myautoconnect, sa);
  74                 if (newsocket->GetFd() > -1)
  75                 {
  76                         /* We're all OK */
  77                 }
  78                 else
  79                 {
  80                         /* Something barfed, show the opers */
  81                         ServerInstance->SNO->WriteToSnoMask('l', "CONNECT: Error connecting \002%s\002: %s.",
  82                                 MyLink->Name.c_str(), newsocket->getError().c_str());
  83                         ServerInstance->GlobalCulls.AddItem(newsocket);
  84                 }
  85         }
  86 }
  87
  88 void ServernameResolver::OnError(const DNS::Query *r)
  89 {
  90         if (r->error == DNS::ERROR_UNLOADED)
  91         {
  92                 // We're being unloaded, skip the snotice and ConnectServer() below to prevent autoconnect creating new sockets
  93                 return;
  94         }
  95
  96         if (query == DNS::QUERY_AAAA)
  97         {
  98                 ServernameResolver* snr = new ServernameResolver(this->manager, host, MyLink, DNS::QUERY_A, myautoconnect);
  99                 try
 100                 {
 101                         this->manager->Process(snr);
 102                         return;
 103                 }
 104                 catch (DNS::Exception &)
 105                 {
 106                         delete snr;
 107                 }
 108         }
 109
 110         ServerInstance->SNO->WriteToSnoMask('l', "CONNECT: Error connecting \002%s\002: Unable to resolve hostname - %s", MyLink->Name.c_str(), this->manager->GetErrorStr(r->error).c_str());
 111         Utils->Creator->ConnectServer(myautoconnect, false);
 112 }
 113
 114 SecurityIPResolver::SecurityIPResolver(Module* me, DNS::Manager* mgr, const std::string& hostname, Link* x, DNS::QueryType qt)
 115         : DNS::Request(mgr, me, hostname, qt)
 116         , MyLink(x), mine(me), host(hostname), query(qt)
 117 {
 118 }
 119
 120 void SecurityIPResolver::OnLookupComplete(const DNS::Query *r)
 121 {
 122         for (std::vector<reference<Link> >::iterator i = Utils->LinkBlocks.begin(); i != Utils->LinkBlocks.end(); ++i)
 123         {
 124                 Link* L = *i;
 125                 if (L->IPAddr == host)
 126                 {
 127                         for (std::vector<DNS::ResourceRecord>::const_iterator j = r->answers.begin(); j != r->answers.end(); ++j)
 128                         {
 129                                 const DNS::ResourceRecord& ans_record = *j;
 130                                 if (ans_record.type == this->question.type)
 131                                         Utils->ValidIPs.push_back(ans_record.rdata);
 132                         }
 133                         break;
 134                 }
 135         }
 136 }
 137
 138 void SecurityIPResolver::OnError(const DNS::Query *r)
 139 {
 140         // This can be called because of us being unloaded but we don't have to do anything differently
 141         if (query == DNS::QUERY_AAAA)
 142         {
 143                 SecurityIPResolver* res = new SecurityIPResolver(mine, this->manager, host, MyLink, DNS::QUERY_A);
 144                 try
 145                 {
 146                         this->manager->Process(res);
 147                         return;
 148                 }
 149                 catch (DNS::Exception &)
 150                 {
 151                         delete res;
 152                 }
 153         }
 154         ServerInstance->Logs->Log(MODNAME, LOG_DEFAULT, "Could not resolve IP associated with Link '%s': %s",
 155                 MyLink->Name.c_str(), this->manager->GetErrorStr(r->error).c_str());
 156 }
 157
 158 CacheRefreshTimer::CacheRefreshTimer()
 159         : Timer(3600, true)
 160 {
 161 }
 162
 163 bool CacheRefreshTimer::Tick(time_t TIME)
 164 {
 165         Utils->RefreshIPCache();
 166         return true;
 167 }