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 int conns = 0, throttled = 0;
  27
  28 class ModuleConnFlood : public Module
  29 {
  30 private:
  31         int seconds, maxconns, timeout, boot_wait;
  32         time_t first;
  33         std::string quitmsg;
  34
  35 public:
  36         ModuleConnFlood()       {
  37
  38                 InitConf();
  39                 Implementation eventlist[] = { I_OnRehash, I_OnUserRegister };
  40                 ServerInstance->Modules->Attach(eventlist, this, 2);
  41         }
  42
  43         virtual ~ModuleConnFlood()
  44         {
  45         }
  46
  47         virtual Version GetVersion()
  48         {
  49                 return Version("Connection throttle", VF_VENDOR);
  50         }
  51
  52         void InitConf()
  53         {
  54                 /* read configuration variables */
  55                 ConfigReader conf;
  56                 /* throttle configuration */
  57                 seconds = conf.ReadInteger("connflood", "seconds", 0, true);
  58                 maxconns = conf.ReadInteger("connflood", "maxconns", 0, true);
  59                 timeout = conf.ReadInteger("connflood", "timeout", 0, true);
  60                 quitmsg = conf.ReadValue("connflood", "quitmsg", 0);
  61
  62                 /* seconds to wait when the server just booted */
  63                 boot_wait = conf.ReadInteger("connflood", "bootwait", 0, true);
  64
  65                 first = ServerInstance->Time();
  66         }
  67
  68         virtual ModResult OnUserRegister(LocalUser* user)
  69         {
  70                 time_t next = ServerInstance->Time();
  71
  72                 if ((ServerInstance->startup_time + boot_wait) > next)
  73                         return MOD_RES_PASSTHRU;
  74
  75                 /* time difference between first and latest connection */
  76                 time_t tdiff = next - first;
  77
  78                 /* increase connection count */
  79                 conns++;
  80
  81                 if (throttled == 1)
  82                 {
  83                         if (tdiff > seconds + timeout)
  84                         {
  85                                 /* expire throttle */
  86                                 throttled = 0;
  87                                 ServerInstance->SNO->WriteGlobalSno('a', "Connection throttle deactivated");
  88                                 return MOD_RES_PASSTHRU;
  89                         }
  90
  91                         ServerInstance->Users->QuitUser(user, quitmsg);
  92                         return MOD_RES_DENY;
  93                 }
  94
  95                 if (tdiff <= seconds)
  96                 {
  97                         if (conns >= maxconns)
  98                         {
  99                                 throttled = 1;
 100                                 ServerInstance->SNO->WriteGlobalSno('a', "Connection throttle activated");
 101                                 ServerInstance->Users->QuitUser(user, quitmsg);
 102                                 return MOD_RES_DENY;
 103                         }
 104                 }
 105                 else
 106                 {
 107                         conns = 1;
 108                         first = next;
 109                 }
 110                 return MOD_RES_PASSTHRU;
 111         }
 112
 113         virtual void OnRehash(User* user)
 114         {
 115                 InitConf();
 116         }
 117
 118 };
 119
 120 MODULE_INIT(ModuleConnFlood)