src/listensocket.cpp

   1 /*       +------------------------------------+
   2  *       | Inspire Internet Relay Chat Daemon |
   3  *       +------------------------------------+
   4  *
   5  *  InspIRCd: (C) 2002-2009 InspIRCd Development Team
   6  * See: http://wiki.inspircd.org/Credits
   7  *
   8  * This program is free but copyrighted software; see
   9  *            the file COPYING for details.
  10  *
  11  * ---------------------------------------------------
  12  */
  13
  14 /* $Core */
  15
  16 #include "inspircd.h"
  17 #include "socket.h"
  18 #include "socketengine.h"
  19
  20 ListenSocket::ListenSocket(ConfigTag* tag, const std::string& addr, int port)
  21         : bind_tag(tag)
  22 {
  23         irc::sockets::sockaddrs bind_to;
  24
  25         // canonicalize address if it is defined
  26         if (!irc::sockets::aptosa(addr, port, bind_to))
  27         {
  28                 fd = -1;
  29                 return;
  30         }
  31         irc::sockets::satoap(bind_to, bind_addr, bind_port);
  32         bind_desc = irc::sockets::satouser(bind_to);
  33
  34         fd = socket(bind_to.sa.sa_family, SOCK_STREAM, 0);
  35
  36         if (this->fd > -1)
  37         {
  38                 ServerInstance->SE->SetReuse(fd);
  39                 int rv = ServerInstance->SE->Bind(this->fd, &bind_to.sa, sizeof(bind_to));
  40                 if (rv >= 0)
  41                         rv = ServerInstance->SE->Listen(this->fd, ServerInstance->Config->MaxConn);
  42
  43                 if (rv < 0)
  44                 {
  45                         ServerInstance->SE->Shutdown(this, 2);
  46                         ServerInstance->SE->Close(this);
  47                         this->fd = -1;
  48                 }
  49                 else
  50                 {
  51                         ServerInstance->SE->NonBlocking(this->fd);
  52                         ServerInstance->SE->AddFd(this, FD_WANT_POLL_READ | FD_WANT_NO_WRITE);
  53                 }
  54         }
  55 }
  56
  57 ListenSocket::~ListenSocket()
  58 {
  59         if (this->GetFd() > -1)
  60         {
  61                 ServerInstance->SE->DelFd(this);
  62                 ServerInstance->Logs->Log("SOCKET", DEBUG,"Shut down listener on fd %d", this->fd);
  63                 if (ServerInstance->SE->Shutdown(this, 2) || ServerInstance->SE->Close(this))
  64                         ServerInstance->Logs->Log("SOCKET", DEBUG,"Failed to cancel listener: %s", strerror(errno));
  65                 this->fd = -1;
  66         }
  67 }
  68
  69 /* Just seperated into another func for tidiness really.. */
  70 void ListenSocket::AcceptInternal()
  71 {
  72         irc::sockets::sockaddrs client;
  73         irc::sockets::sockaddrs server;
  74
  75         socklen_t length = sizeof(client);
  76         int incomingSockfd = ServerInstance->SE->Accept(this, &client.sa, &length);
  77
  78         ServerInstance->Logs->Log("SOCKET",DEBUG,"HandleEvent for Listensoket %s nfd=%d", bind_desc.c_str(), incomingSockfd);
  79         if (incomingSockfd < 0)
  80         {
  81                 ServerInstance->stats->statsRefused++;
  82                 return;
  83         }
  84
  85         socklen_t sz = sizeof(server);
  86         if (getsockname(incomingSockfd, &server.sa, &sz))
  87                 ServerInstance->Logs->Log("SOCKET", DEBUG, "Can't get peername: %s", strerror(errno));
  88
  89         /*
  90          * XXX -
  91          * this is done as a safety check to keep the file descriptors within range of fd_ref_table.
  92          * its a pretty big but for the moment valid assumption:
  93          * file descriptors are handed out starting at 0, and are recycled as theyre freed.
  94          * therefore if there is ever an fd over 65535, 65536 clients must be connected to the
  95          * irc server at once (or the irc server otherwise initiating this many connections, files etc)
  96          * which for the time being is a physical impossibility (even the largest networks dont have more
  97          * than about 10,000 users on ONE server!)
  98          */
  99         if (incomingSockfd >= ServerInstance->SE->GetMaxFds())
 100         {
 101                 ServerInstance->Logs->Log("SOCKET", DEBUG, "Server is full");
 102                 ServerInstance->SE->Shutdown(incomingSockfd, 2);
 103                 ServerInstance->SE->Close(incomingSockfd);
 104                 ServerInstance->stats->statsRefused++;
 105                 return;
 106         }
 107
 108         if (client.sa.sa_family == AF_INET6)
 109         {
 110                 /*
 111                  * This case is the be all and end all patch to catch and nuke 4in6
 112                  * instead of special-casing shit all over the place and wreaking merry
 113                  * havoc with crap, instead, we just recreate sockaddr and strip ::ffff: prefix
 114                  * if it's a 4in6 IP.
 115                  *
 116                  * This is, of course, much improved over the older way of handling this
 117                  * (pretend it doesn't exist + hack around it -- yes, both were done!)
 118                  *
 119                  * Big, big thanks to danieldg for his work on this.
 120                  * -- w00t
 121                  */
 122                 static const unsigned char prefix4in6[12] = { 0,0,0,0, 0,0,0,0, 0,0,0xFF,0xFF };
 123                 if (!memcmp(prefix4in6, &client.in6.sin6_addr, 12))
 124                 {
 125                         // recreate as a sockaddr_in using the IPv4 IP
 126                         uint16_t sport = client.in6.sin6_port;
 127                         uint32_t addr = *reinterpret_cast<uint32_t*>(client.in6.sin6_addr.s6_addr + 12);
 128                         client.in4.sin_family = AF_INET;
 129                         client.in4.sin_port = sport;
 130                         client.in4.sin_addr.s_addr = addr;
 131
 132                         sport = server.in6.sin6_port;
 133                         addr = *reinterpret_cast<uint32_t*>(server.in6.sin6_addr.s6_addr + 12);
 134                         server.in4.sin_family = AF_INET;
 135                         server.in4.sin_port = sport;
 136                         server.in4.sin_addr.s_addr = addr;
 137                 }
 138         }
 139
 140         ServerInstance->SE->NonBlocking(incomingSockfd);
 141
 142         ModResult res;
 143         FIRST_MOD_RESULT(OnAcceptConnection, res, (incomingSockfd, this, &client, &server));
 144         if (res == MOD_RES_PASSTHRU)
 145         {
 146                 std::string type = bind_tag->getString("type", "clients");
 147                 if (type == "clients")
 148                 {
 149                         ServerInstance->Users->AddUser(incomingSockfd, this, &client, &server);
 150                         res = MOD_RES_ALLOW;
 151                 }
 152         }
 153         if (res == MOD_RES_ALLOW)
 154         {
 155                 ServerInstance->stats->statsAccept++;
 156         }
 157         else
 158         {
 159                 ServerInstance->stats->statsRefused++;
 160                 ServerInstance->Logs->Log("SOCKET",DEFAULT,"Refusing connection on %s - %s",
 161                         bind_desc.c_str(), res == MOD_RES_DENY ? "Connection refused by module" : "Module for this port not found");
 162                 ServerInstance->SE->Close(incomingSockfd);
 163         }
 164 }
 165
 166 void ListenSocket::HandleEvent(EventType e, int err)
 167 {
 168         switch (e)
 169         {
 170                 case EVENT_ERROR:
 171                         ServerInstance->Logs->Log("SOCKET",DEFAULT,"ListenSocket::HandleEvent() received a socket engine error event! well shit! '%s'", strerror(err));
 172                         break;
 173                 case EVENT_WRITE:
 174                         ServerInstance->Logs->Log("SOCKET",DEBUG,"*** BUG *** ListenSocket::HandleEvent() got a WRITE event!!!");
 175                         break;
 176                 case EVENT_READ:
 177                         this->AcceptInternal();
 178                         break;
 179         }
 180 }