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                 InitConf();
  41                 Implementation eventlist[] = { I_OnRehash, I_OnUserRegister };
  42                 ServerInstance->Modules->Attach(eventlist, this, 2);
  43         }
  44
  45         virtual Version GetVersion()
  46         {
  47                 return Version("Connection throttle", VF_VENDOR);
  48         }
  49
  50         void InitConf()
  51         {
  52                 /* read configuration variables */
  53                 ConfigReader conf;
  54                 /* throttle configuration */
  55                 seconds = conf.ReadInteger("connflood", "seconds", 0, true);
  56                 maxconns = conf.ReadInteger("connflood", "maxconns", 0, true);
  57                 timeout = conf.ReadInteger("connflood", "timeout", 0, true);
  58                 quitmsg = conf.ReadValue("connflood", "quitmsg", 0);
  59
  60                 /* seconds to wait when the server just booted */
  61                 boot_wait = conf.ReadInteger("connflood", "bootwait", 0, true);
  62
  63                 first = ServerInstance->Time();
  64         }
  65
  66         virtual ModResult OnUserRegister(LocalUser* user)
  67         {
  68                 time_t next = ServerInstance->Time();
  69
  70                 if ((ServerInstance->startup_time + boot_wait) > next)
  71                         return MOD_RES_PASSTHRU;
  72
  73                 /* time difference between first and latest connection */
  74                 time_t tdiff = next - first;
  75
  76                 /* increase connection count */
  77                 conns++;
  78
  79                 if (throttled)
  80                 {
  81                         if (tdiff > seconds + timeout)
  82                         {
  83                                 /* expire throttle */
  84                                 throttled = false;
  85                                 ServerInstance->SNO->WriteGlobalSno('a', "Connection throttle deactivated");
  86                                 return MOD_RES_PASSTHRU;
  87                         }
  88
  89                         ServerInstance->Users->QuitUser(user, quitmsg);
  90                         return MOD_RES_DENY;
  91                 }
  92
  93                 if (tdiff <= seconds)
  94                 {
  95                         if (conns >= maxconns)
  96                         {
  97                                 throttled = true;
  98                                 ServerInstance->SNO->WriteGlobalSno('a', "Connection throttle activated");
  99                                 ServerInstance->Users->QuitUser(user, quitmsg);
 100                                 return MOD_RES_DENY;
 101                         }
 102                 }
 103                 else
 104                 {
 105                         conns = 1;
 106                         first = next;
 107                 }
 108                 return MOD_RES_PASSTHRU;
 109         }
 110
 111         virtual void OnRehash(User* user)
 112         {
 113                 InitConf();
 114         }
 115
 116 };
 117
 118 MODULE_INIT(ModuleConnFlood)