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         int seconds, timeout, boot_wait;
  27         unsigned int conns;
  28         unsigned int maxconns;
  29         bool throttled;
  30         time_t first;
  31         std::string quitmsg;
  32
  33 public:
  34         ModuleConnFlood()
  35                 : conns(0), throttled(false)
  36         {
  37         }
  38
  39         void init() CXX11_OVERRIDE
  40         {
  41                 InitConf();
  42         }
  43
  44         Version GetVersion() CXX11_OVERRIDE
  45         {
  46                 return Version("Connection throttle", VF_VENDOR);
  47         }
  48
  49         void InitConf()
  50         {
  51                 /* read configuration variables */
  52                 ConfigTag* tag = ServerInstance->Config->ConfValue("connflood");
  53                 /* throttle configuration */
  54                 seconds = tag->getInt("seconds");
  55                 maxconns = tag->getInt("maxconns");
  56                 timeout = tag->getInt("timeout");
  57                 quitmsg = tag->getString("quitmsg");
  58
  59                 /* seconds to wait when the server just booted */
  60                 boot_wait = tag->getInt("bootwait");
  61
  62                 first = ServerInstance->Time();
  63         }
  64
  65         ModResult OnUserRegister(LocalUser* user) CXX11_OVERRIDE
  66         {
  67                 if (user->exempt)
  68                         return MOD_RES_PASSTHRU;
  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)
  82                 {
  83                         if (tdiff > seconds + timeout)
  84                         {
  85                                 /* expire throttle */
  86                                 throttled = false;
  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 = true;
 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         void OnRehash(User* user) CXX11_OVERRIDE
 114         {
 115                 InitConf();
 116         }
 117
 118 };
 119
 120 MODULE_INIT(ModuleConnFlood)