src/modules/m_joinflood.cpp

   1 /*       +------------------------------------+
   2  *       | Inspire Internet Relay Chat Daemon |
   3  *       +------------------------------------+
   4  *
   5  *  InspIRCd: (C) 2002-2009 InspIRCd Development Team
   6  * See: http://wiki.inspircd.org/Credits
   7  *
   8  * This program is free but copyrighted software; see
   9  *            the file COPYING for details.
  10  *
  11  * ---------------------------------------------------
  12  */
  13
  14 #include "inspircd.h"
  15
  16 /* $ModDesc: Provides channel mode +j (join flood protection) */
  17
  18 /** Holds settings and state associated with channel mode +j
  19  */
  20 class joinfloodsettings : public classbase
  21 {
  22  public:
  23         int secs;
  24         int joins;
  25         time_t reset;
  26         time_t unlocktime;
  27         int counter;
  28         bool locked;
  29
  30         joinfloodsettings(int b, int c) : secs(b), joins(c)
  31         {
  32                 reset = ServerInstance->Time() + secs;
  33                 counter = 0;
  34                 locked = false;
  35         };
  36
  37         void addjoin()
  38         {
  39                 counter++;
  40                 if (ServerInstance->Time() > reset)
  41                 {
  42                         counter = 0;
  43                         reset = ServerInstance->Time() + secs;
  44                 }
  45         }
  46
  47         bool shouldlock()
  48         {
  49                 return (counter >= this->joins);
  50         }
  51
  52         void clear()
  53         {
  54                 counter = 0;
  55         }
  56
  57         bool islocked()
  58         {
  59                 if (locked)
  60                 {
  61                         if (ServerInstance->Time() > unlocktime)
  62                         {
  63                                 locked = false;
  64                                 return false;
  65                         }
  66                         else
  67                         {
  68                                 return true;
  69                         }
  70                 }
  71                 return false;
  72         }
  73
  74         void lock()
  75         {
  76                 locked = true;
  77                 unlocktime = ServerInstance->Time() + 60;
  78         }
  79
  80 };
  81
  82 /** Handles channel mode +j
  83  */
  84 class JoinFlood : public ModeHandler
  85 {
  86  public:
  87         SimpleExtItem<joinfloodsettings> ext;
  88         JoinFlood(Module* Creator) : ModeHandler(Creator, 'j', PARAM_SETONLY, MODETYPE_CHANNEL),
  89                 ext("joinflood", Creator) { }
  90
  91         ModePair ModeSet(User* source, User* dest, Channel* channel, const std::string &parameter)
  92         {
  93                 joinfloodsettings* x = ext.get(channel);
  94                 if (x)
  95                         return std::make_pair(true, ConvToStr(x->joins)+":"+ConvToStr(x->secs));
  96                 else
  97                         return std::make_pair(false, parameter);
  98         }
  99
 100         ModeAction OnModeChange(User* source, User* dest, Channel* channel, std::string &parameter, bool adding)
 101         {
 102                 if (adding)
 103                 {
 104                         char ndata[MAXBUF];
 105                         char* data = ndata;
 106                         strlcpy(ndata,parameter.c_str(),MAXBUF);
 107                         char* joins = data;
 108                         char* secs = NULL;
 109                         while (*data)
 110                         {
 111                                 if (*data == ':')
 112                                 {
 113                                         *data = 0;
 114                                         data++;
 115                                         secs = data;
 116                                         break;
 117                                 }
 118                                 else data++;
 119                         }
 120                         if (secs)
 121
 122                         {
 123                                 /* Set up the flood parameters for this channel */
 124                                 int njoins = atoi(joins);
 125                                 int nsecs = atoi(secs);
 126                                 if ((njoins<1) || (nsecs<1))
 127                                 {
 128                                         source->WriteNumeric(608, "%s %s :Invalid flood parameter",source->nick.c_str(),channel->name.c_str());
 129                                         parameter.clear();
 130                                         return MODEACTION_DENY;
 131                                 }
 132                                 else
 133                                 {
 134                                         joinfloodsettings* f = ext.get(channel);
 135                                         if (!f)
 136                                         {
 137                                                 parameter = ConvToStr(njoins) + ":" +ConvToStr(nsecs);
 138                                                 f = new joinfloodsettings(nsecs, njoins);
 139                                                 ext.set(channel, f);
 140                                                 channel->SetModeParam('j', parameter);
 141                                                 return MODEACTION_ALLOW;
 142                                         }
 143                                         else
 144                                         {
 145                                                 std::string cur_param = channel->GetModeParameter('j');
 146                                                 parameter = ConvToStr(njoins) + ":" +ConvToStr(nsecs);
 147                                                 if (cur_param == parameter)
 148                                                 {
 149                                                         // mode params match
 150                                                         return MODEACTION_DENY;
 151                                                 }
 152                                                 else
 153                                                 {
 154                                                         // new mode param, replace old with new
 155                                                         if ((nsecs > 0) && (njoins > 0))
 156                                                         {
 157                                                                 f = new joinfloodsettings(nsecs, njoins);
 158                                                                 ext.set(channel, f);
 159                                                                 channel->SetModeParam('j', parameter);
 160                                                                 return MODEACTION_ALLOW;
 161                                                         }
 162                                                         else
 163                                                         {
 164                                                                 return MODEACTION_DENY;
 165                                                         }
 166                                                 }
 167                                         }
 168                                 }
 169                         }
 170                         else
 171                         {
 172                                 source->WriteNumeric(608, "%s %s :Invalid flood parameter",source->nick.c_str(),channel->name.c_str());
 173                                 return MODEACTION_DENY;
 174                         }
 175                 }
 176                 else
 177                 {
 178                         joinfloodsettings* f = ext.get(channel);
 179                         if (f)
 180                         {
 181                                 ext.unset(channel);
 182                                 channel->SetModeParam('j', "");
 183                                 return MODEACTION_ALLOW;
 184                         }
 185                 }
 186                 return MODEACTION_DENY;
 187         }
 188 };
 189
 190 class ModuleJoinFlood : public Module
 191 {
 192
 193         JoinFlood jf;
 194
 195  public:
 196
 197         ModuleJoinFlood()
 198                 : jf(this)
 199         {
 200
 201                 if (!ServerInstance->Modes->AddMode(&jf))
 202                         throw ModuleException("Could not add new modes!");
 203                 Extensible::Register(&jf.ext);
 204                 Implementation eventlist[] = { I_OnChannelDelete, I_OnUserPreJoin, I_OnUserJoin };
 205                 ServerInstance->Modules->Attach(eventlist, this, 3);
 206         }
 207
 208         ModResult OnUserPreJoin(User* user, Channel* chan, const char* cname, std::string &privs, const std::string &keygiven)
 209         {
 210                 if (chan)
 211                 {
 212                         joinfloodsettings *f = jf.ext.get(chan);
 213                         if (f && f->islocked())
 214                         {
 215                                 user->WriteNumeric(609, "%s %s :This channel is temporarily unavailable (+j). Please try again later.",user->nick.c_str(),chan->name.c_str());
 216                                 return MOD_RES_DENY;
 217                         }
 218                 }
 219                 return MOD_RES_PASSTHRU;
 220         }
 221
 222         void OnUserJoin(Membership* memb, bool sync, bool created, CUList& excepts)
 223         {
 224                 /* We arent interested in JOIN events caused by a network burst */
 225                 if (sync)
 226                         return;
 227
 228                 joinfloodsettings *f = jf.ext.get(memb->chan);
 229
 230                 /* But all others are OK */
 231                 if (f)
 232                 {
 233                         f->addjoin();
 234                         if (f->shouldlock())
 235                         {
 236                                 f->clear();
 237                                 f->lock();
 238                                 memb->chan->WriteChannelWithServ((char*)ServerInstance->Config->ServerName, "NOTICE %s :This channel has been closed to new users for 60 seconds because there have been more than %d joins in %d seconds.", memb->chan->name.c_str(), f->joins, f->secs);
 239                         }
 240                 }
 241         }
 242
 243         ~ModuleJoinFlood()
 244         {
 245                 ServerInstance->Modes->DelMode(&jf);
 246         }
 247
 248         Version GetVersion()
 249         {
 250                 return Version("Provides channel mode +j (join flood protection)", VF_COMMON | VF_VENDOR, API_VERSION);
 251         }
 252 };
 253
 254 MODULE_INIT(ModuleJoinFlood)