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 /* $ModDesc: Connection throttle */
  25
  26 class ModuleConnFlood : public Module
  27 {
  28 private:
  29         int seconds, timeout, boot_wait;
  30         unsigned int conns;
  31         unsigned int maxconns;
  32         bool throttled;
  33         time_t first;
  34         std::string quitmsg;
  35
  36 public:
  37         ModuleConnFlood()
  38                 : conns(0), throttled(false)
  39         {
  40         }
  41
  42         void init()
  43         {
  44                 InitConf();
  45                 Implementation eventlist[] = { I_OnRehash, I_OnUserRegister };
  46                 ServerInstance->Modules->Attach(eventlist, this, sizeof(eventlist)/sizeof(Implementation));
  47         }
  48
  49         virtual Version GetVersion()
  50         {
  51                 return Version("Connection throttle", VF_VENDOR);
  52         }
  53
  54         void InitConf()
  55         {
  56                 /* read configuration variables */
  57                 ConfigTag* tag = ServerInstance->Config->ConfValue("connflood");
  58                 /* throttle configuration */
  59                 seconds = tag->getInt("seconds");
  60                 maxconns = tag->getInt("maxconns");
  61                 timeout = tag->getInt("timeout");
  62                 quitmsg = tag->getString("quitmsg");
  63
  64                 /* seconds to wait when the server just booted */
  65                 boot_wait = tag->getInt("bootwait");
  66
  67                 first = ServerInstance->Time();
  68         }
  69
  70         virtual ModResult OnUserRegister(LocalUser* user)
  71         {
  72                 if (user->exempt)
  73                         return MOD_RES_PASSTHRU;
  74
  75                 time_t next = ServerInstance->Time();
  76
  77                 if ((ServerInstance->startup_time + boot_wait) > next)
  78                         return MOD_RES_PASSTHRU;
  79
  80                 /* time difference between first and latest connection */
  81                 time_t tdiff = next - first;
  82
  83                 /* increase connection count */
  84                 conns++;
  85
  86                 if (throttled)
  87                 {
  88                         if (tdiff > seconds + timeout)
  89                         {
  90                                 /* expire throttle */
  91                                 throttled = false;
  92                                 ServerInstance->SNO->WriteGlobalSno('a', "Connection throttle deactivated");
  93                                 return MOD_RES_PASSTHRU;
  94                         }
  95
  96                         ServerInstance->Users->QuitUser(user, quitmsg);
  97                         return MOD_RES_DENY;
  98                 }
  99
 100                 if (tdiff <= seconds)
 101                 {
 102                         if (conns >= maxconns)
 103                         {
 104                                 throttled = true;
 105                                 ServerInstance->SNO->WriteGlobalSno('a', "Connection throttle activated");
 106                                 ServerInstance->Users->QuitUser(user, quitmsg);
 107                                 return MOD_RES_DENY;
 108                         }
 109                 }
 110                 else
 111                 {
 112                         conns = 1;
 113                         first = next;
 114                 }
 115                 return MOD_RES_PASSTHRU;
 116         }
 117
 118         virtual void OnRehash(User* user)
 119         {
 120                 InitConf();
 121         }
 122
 123 };
 124
 125 MODULE_INIT(ModuleConnFlood)