src/modules/m_messageflood.cpp

   1 /*
   2  * InspIRCd -- Internet Relay Chat Daemon
   3  *
   4  *   Copyright (C) 2009 Daniel De Graaf <danieldg@inspircd.org>
   5  *   Copyright (C) 2008 Pippijn van Steenhoven <pip88nl@gmail.com>
   6  *   Copyright (C) 2007 Robin Burchell <robin+git@viroteck.net>
   7  *   Copyright (C) 2007 John Brooks <john.brooks@dereferenced.net>
   8  *   Copyright (C) 2007 Dennis Friis <peavey@inspircd.org>
   9  *   Copyright (C) 2006 Craig Edwards <craigedwards@brainbox.cc>
  10  *   Copyright (C) 2006 Oliver Lupton <oliverlupton@gmail.com>
  11  *
  12  * This file is part of InspIRCd.  InspIRCd is free software: you can
  13  * redistribute it and/or modify it under the terms of the GNU General Public
  14  * License as published by the Free Software Foundation, version 2.
  15  *
  16  * This program is distributed in the hope that it will be useful, but WITHOUT
  17  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  18  * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
  19  * details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  23  */
  24
  25
  26 #include "inspircd.h"
  27
  28 /* $ModDesc: Provides channel mode +f (message flood protection) */
  29
  30 /** Holds flood settings and state for mode +f
  31  */
  32 class floodsettings
  33 {
  34  public:
  35         bool ban;
  36         int secs;
  37         int lines;
  38         time_t reset;
  39         std::map<User*,int> counters;
  40
  41         floodsettings(bool a, int b, int c) : ban(a), secs(b), lines(c)
  42         {
  43                 reset = ServerInstance->Time() + secs;
  44         };
  45
  46         void addmessage(User* who)
  47         {
  48                 std::map<User*,int>::iterator iter = counters.find(who);
  49                 if (iter != counters.end())
  50                 {
  51                         iter->second++;
  52                 }
  53                 else
  54                 {
  55                         counters[who] = 1;
  56                 }
  57                 if (ServerInstance->Time() > reset)
  58                 {
  59                         counters.clear();
  60                         reset = ServerInstance->Time() + secs;
  61                 }
  62         }
  63
  64         bool shouldkick(User* who)
  65         {
  66                 std::map<User*,int>::iterator iter = counters.find(who);
  67                 if (iter != counters.end())
  68                 {
  69                         return (iter->second >= this->lines);
  70                 }
  71                 else return false;
  72         }
  73
  74         void clear(User* who)
  75         {
  76                 std::map<User*,int>::iterator iter = counters.find(who);
  77                 if (iter != counters.end())
  78                 {
  79                         counters.erase(iter);
  80                 }
  81         }
  82 };
  83
  84 /** Handles channel mode +f
  85  */
  86 class MsgFlood : public ModeHandler
  87 {
  88  public:
  89         SimpleExtItem<floodsettings> ext;
  90         MsgFlood(Module* Creator) : ModeHandler(Creator, "flood", 'f', PARAM_SETONLY, MODETYPE_CHANNEL),
  91                 ext("messageflood", Creator) { }
  92
  93         ModeAction OnModeChange(User* source, User* dest, Channel* channel, std::string &parameter, bool adding)
  94         {
  95                 floodsettings *f = ext.get(channel);
  96
  97                 if (adding)
  98                 {
  99                         char ndata[MAXBUF];
 100                         char* data = ndata;
 101                         strlcpy(ndata,parameter.c_str(),MAXBUF);
 102                         char* lines = data;
 103                         char* secs = NULL;
 104                         bool ban = false;
 105                         if (*data == '*')
 106                         {
 107                                 ban = true;
 108                                 lines++;
 109                         }
 110                         else
 111                         {
 112                                 ban = false;
 113                         }
 114                         while (*data)
 115                         {
 116                                 if (*data == ':')
 117                                 {
 118                                         *data = 0;
 119                                         data++;
 120                                         secs = data;
 121                                         break;
 122                                 }
 123                                 else data++;
 124                         }
 125                         if (secs)
 126                         {
 127                                 /* Set up the flood parameters for this channel */
 128                                 int nlines = atoi(lines);
 129                                 int nsecs = atoi(secs);
 130                                 if ((nlines<2) || (nsecs<1))
 131                                 {
 132                                         source->WriteNumeric(608, "%s %s :Invalid flood parameter",source->nick.c_str(),channel->name.c_str());
 133                                         parameter.clear();
 134                                         return MODEACTION_DENY;
 135                                 }
 136                                 else
 137                                 {
 138                                         if (!f)
 139                                         {
 140                                                 parameter = std::string(ban ? "*" : "") + ConvToStr(nlines) + ":" +ConvToStr(nsecs);
 141                                                 f = new floodsettings(ban,nsecs,nlines);
 142                                                 ext.set(channel, f);
 143                                                 channel->SetModeParam('f', parameter);
 144                                                 return MODEACTION_ALLOW;
 145                                         }
 146                                         else
 147                                         {
 148                                                 std::string cur_param = channel->GetModeParameter('f');
 149                                                 parameter = std::string(ban ? "*" : "") + ConvToStr(nlines) + ":" +ConvToStr(nsecs);
 150                                                 if (cur_param == parameter)
 151                                                 {
 152                                                         // mode params match
 153                                                         return MODEACTION_DENY;
 154                                                 }
 155                                                 else
 156                                                 {
 157                                                         if ((((nlines != f->lines) || (nsecs != f->secs) || (ban != f->ban))) && (((nsecs > 0) && (nlines > 0))))
 158                                                         {
 159                                                                 floodsettings *fs = new floodsettings(ban,nsecs,nlines);
 160                                                                 ext.set(channel, fs);
 161                                                                 channel->SetModeParam('f', parameter);
 162                                                                 return MODEACTION_ALLOW;
 163                                                         }
 164                                                         else
 165                                                         {
 166                                                                 return MODEACTION_DENY;
 167                                                         }
 168                                                 }
 169                                         }
 170                                 }
 171                         }
 172                         else
 173                         {
 174                                 source->WriteNumeric(608, "%s %s :Invalid flood parameter",source->nick.c_str(),channel->name.c_str());
 175                                 parameter.clear();
 176                                 return MODEACTION_DENY;
 177                         }
 178                 }
 179                 else
 180                 {
 181                         if (f)
 182                         {
 183                                 ext.unset(channel);
 184                                 channel->SetModeParam('f', "");
 185                                 return MODEACTION_ALLOW;
 186                         }
 187                 }
 188
 189                 return MODEACTION_DENY;
 190         }
 191 };
 192
 193 class ModuleMsgFlood : public Module
 194 {
 195         MsgFlood mf;
 196
 197  public:
 198
 199         ModuleMsgFlood()
 200                 : mf(this)
 201         {
 202                 if (!ServerInstance->Modes->AddMode(&mf))
 203                         throw ModuleException("Could not add new modes!");
 204                 ServerInstance->Extensions.Register(&mf.ext);
 205                 Implementation eventlist[] = { I_OnUserPreNotice, I_OnUserPreMessage };
 206                 ServerInstance->Modules->Attach(eventlist, this, 2);
 207         }
 208
 209         ModResult ProcessMessages(User* user,Channel* dest, const std::string &text)
 210         {
 211                 ModResult res = ServerInstance->OnCheckExemption(user,dest,"flood");
 212                 if (!IS_LOCAL(user) || res == MOD_RES_ALLOW)
 213                         return MOD_RES_PASSTHRU;
 214
 215                 floodsettings *f = mf.ext.get(dest);
 216                 if (f)
 217                 {
 218                         f->addmessage(user);
 219                         if (f->shouldkick(user))
 220                         {
 221                                 /* Youre outttta here! */
 222                                 f->clear(user);
 223                                 if (f->ban)
 224                                 {
 225                                         std::vector<std::string> parameters;
 226                                         parameters.push_back(dest->name);
 227                                         parameters.push_back("+b");
 228                                         parameters.push_back(user->MakeWildHost());
 229                                         ServerInstance->SendGlobalMode(parameters, ServerInstance->FakeClient);
 230                                 }
 231
 232                                 char kickmessage[MAXBUF];
 233                                 snprintf(kickmessage, MAXBUF, "Channel flood triggered (limit is %d lines in %d secs)", f->lines, f->secs);
 234
 235                                 dest->KickUser(ServerInstance->FakeClient, user, kickmessage);
 236
 237                                 return MOD_RES_DENY;
 238                         }
 239                 }
 240
 241                 return MOD_RES_PASSTHRU;
 242         }
 243
 244         ModResult OnUserPreMessage(User *user, void *dest, int target_type, std::string &text, char status, CUList &exempt_list)
 245         {
 246                 if (target_type == TYPE_CHANNEL)
 247                         return ProcessMessages(user,(Channel*)dest,text);
 248
 249                 return MOD_RES_PASSTHRU;
 250         }
 251
 252         ModResult OnUserPreNotice(User *user, void *dest, int target_type, std::string &text, char status, CUList &exempt_list)
 253         {
 254                 if (target_type == TYPE_CHANNEL)
 255                         return ProcessMessages(user,(Channel*)dest,text);
 256
 257                 return MOD_RES_PASSTHRU;
 258         }
 259
 260         ~ModuleMsgFlood()
 261         {
 262         }
 263
 264         Version GetVersion()
 265         {
 266                 return Version("Provides channel mode +f (message flood protection)", VF_VENDOR);
 267         }
 268 };
 269
 270 MODULE_INIT(ModuleMsgFlood)