src/modules/m_connflood.cpp

   1 /*
   2  * InspIRCd -- Internet Relay Chat Daemon
   3  *
   4  *   Copyright (C) 2007 Dennis Friis <peavey@inspircd.org>
   5  *   Copyright (C) 2007 Robin Burchell <robin+git@viroteck.net>
   6  *   Copyright (C) 2006 Craig Edwards <craigedwards@brainbox.cc>
   7  *
   8  * This file is part of InspIRCd.  InspIRCd is free software: you can
   9  * redistribute it and/or modify it under the terms of the GNU General Public
  10  * License as published by the Free Software Foundation, version 2.
  11  *
  12  * This program is distributed in the hope that it will be useful, but WITHOUT
  13  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  14  * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
  15  * details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21
  22 #include "inspircd.h"
  23
  24 class ModuleConnFlood : public Module
  25 {
  26         unsigned int seconds;
  27         unsigned int timeout;
  28         unsigned int boot_wait;
  29         unsigned int conns;
  30         unsigned int maxconns;
  31         bool throttled;
  32         time_t first;
  33         std::string quitmsg;
  34
  35 public:
  36         ModuleConnFlood()
  37                 : conns(0), throttled(false)
  38         {
  39         }
  40
  41         Version GetVersion() CXX11_OVERRIDE
  42         {
  43                 return Version("Connection throttle", VF_VENDOR);
  44         }
  45
  46         void ReadConfig(ConfigStatus& status) CXX11_OVERRIDE
  47         {
  48                 /* read configuration variables */
  49                 ConfigTag* tag = ServerInstance->Config->ConfValue("connflood");
  50                 /* throttle configuration */
  51                 seconds = tag->getDuration("period", tag->getDuration("seconds", 30));
  52                 maxconns = tag->getUInt("maxconns", 3);
  53                 timeout = tag->getDuration("timeout", 30);
  54                 quitmsg = tag->getString("quitmsg");
  55
  56                 /* seconds to wait when the server just booted */
  57                 boot_wait = tag->getDuration("bootwait", 60*2);
  58
  59                 first = ServerInstance->Time();
  60         }
  61
  62         ModResult OnUserRegister(LocalUser* user) CXX11_OVERRIDE
  63         {
  64                 if (user->exempt)
  65                         return MOD_RES_PASSTHRU;
  66
  67                 time_t next = ServerInstance->Time();
  68
  69                 if ((ServerInstance->startup_time + boot_wait) > next)
  70                         return MOD_RES_PASSTHRU;
  71
  72                 /* time difference between first and latest connection */
  73                 time_t tdiff = next - first;
  74
  75                 /* increase connection count */
  76                 conns++;
  77
  78                 if (throttled)
  79                 {
  80                         if (tdiff > seconds + timeout)
  81                         {
  82                                 /* expire throttle */
  83                                 throttled = false;
  84                                 ServerInstance->SNO->WriteGlobalSno('a', "Connection throttle deactivated");
  85                                 return MOD_RES_PASSTHRU;
  86                         }
  87
  88                         ServerInstance->Users->QuitUser(user, quitmsg);
  89                         return MOD_RES_DENY;
  90                 }
  91
  92                 if (tdiff <= seconds)
  93                 {
  94                         if (conns >= maxconns)
  95                         {
  96                                 throttled = true;
  97                                 ServerInstance->SNO->WriteGlobalSno('a', "Connection throttle activated");
  98                                 ServerInstance->Users->QuitUser(user, quitmsg);
  99                                 return MOD_RES_DENY;
 100                         }
 101                 }
 102                 else
 103                 {
 104                         conns = 1;
 105                         first = next;
 106                 }
 107                 return MOD_RES_PASSTHRU;
 108         }
 109 };
 110
 111 MODULE_INIT(ModuleConnFlood)