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