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                 Implementation eventlist[] = { I_OnRehash, I_OnUserRegister };
  43                 ServerInstance->Modules->Attach(eventlist, this, sizeof(eventlist)/sizeof(Implementation));
  44         }
  45
  46         Version GetVersion() CXX11_OVERRIDE
  47         {
  48                 return Version("Connection throttle", VF_VENDOR);
  49         }
  50
  51         void InitConf()
  52         {
  53                 /* read configuration variables */
  54                 ConfigTag* tag = ServerInstance->Config->ConfValue("connflood");
  55                 /* throttle configuration */
  56                 seconds = tag->getInt("seconds");
  57                 maxconns = tag->getInt("maxconns");
  58                 timeout = tag->getInt("timeout");
  59                 quitmsg = tag->getString("quitmsg");
  60
  61                 /* seconds to wait when the server just booted */
  62                 boot_wait = tag->getInt("bootwait");
  63
  64                 first = ServerInstance->Time();
  65         }
  66
  67         ModResult OnUserRegister(LocalUser* user) CXX11_OVERRIDE
  68         {
  69                 if (user->exempt)
  70                         return MOD_RES_PASSTHRU;
  71
  72                 time_t next = ServerInstance->Time();
  73
  74                 if ((ServerInstance->startup_time + boot_wait) > next)
  75                         return MOD_RES_PASSTHRU;
  76
  77                 /* time difference between first and latest connection */
  78                 time_t tdiff = next - first;
  79
  80                 /* increase connection count */
  81                 conns++;
  82
  83                 if (throttled)
  84                 {
  85                         if (tdiff > seconds + timeout)
  86                         {
  87                                 /* expire throttle */
  88                                 throttled = false;
  89                                 ServerInstance->SNO->WriteGlobalSno('a', "Connection throttle deactivated");
  90                                 return MOD_RES_PASSTHRU;
  91                         }
  92
  93                         ServerInstance->Users->QuitUser(user, quitmsg);
  94                         return MOD_RES_DENY;
  95                 }
  96
  97                 if (tdiff <= seconds)
  98                 {
  99                         if (conns >= maxconns)
 100                         {
 101                                 throttled = true;
 102                                 ServerInstance->SNO->WriteGlobalSno('a', "Connection throttle activated");
 103                                 ServerInstance->Users->QuitUser(user, quitmsg);
 104                                 return MOD_RES_DENY;
 105                         }
 106                 }
 107                 else
 108                 {
 109                         conns = 1;
 110                         first = next;
 111                 }
 112                 return MOD_RES_PASSTHRU;
 113         }
 114
 115         void OnRehash(User* user) CXX11_OVERRIDE
 116         {
 117                 InitConf();
 118         }
 119
 120 };
 121
 122 MODULE_INIT(ModuleConnFlood)