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