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
  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, "joinflood", 'j', PARAM_SETONLY, MODETYPE_CHANNEL),
  89                 ext("joinflood", Creator) { }
  90
  91         ModeAction OnModeChange(User* source, User* dest, Channel* channel, std::string &parameter, bool adding)
  92         {
  93                 if (adding)
  94                 {
  95                         char ndata[MAXBUF];
  96                         char* data = ndata;
  97                         strlcpy(ndata,parameter.c_str(),MAXBUF);
  98                         char* joins = data;
  99                         char* secs = NULL;
 100                         while (*data)
 101                         {
 102                                 if (*data == ':')
 103                                 {
 104                                         *data = 0;
 105                                         data++;
 106                                         secs = data;
 107                                         break;
 108                                 }
 109                                 else data++;
 110                         }
 111                         if (secs)
 112
 113                         {
 114                                 /* Set up the flood parameters for this channel */
 115                                 int njoins = atoi(joins);
 116                                 int nsecs = atoi(secs);
 117                                 if ((njoins<1) || (nsecs<1))
 118                                 {
 119                                         source->WriteNumeric(608, "%s %s :Invalid flood parameter",source->nick.c_str(),channel->name.c_str());
 120                                         parameter.clear();
 121                                         return MODEACTION_DENY;
 122                                 }
 123                                 else
 124                                 {
 125                                         joinfloodsettings* f = ext.get(channel);
 126                                         if (!f)
 127                                         {
 128                                                 parameter = ConvToStr(njoins) + ":" +ConvToStr(nsecs);
 129                                                 f = new joinfloodsettings(nsecs, njoins);
 130                                                 ext.set(channel, f);
 131                                                 channel->SetModeParam('j', parameter);
 132                                                 return MODEACTION_ALLOW;
 133                                         }
 134                                         else
 135                                         {
 136                                                 std::string cur_param = channel->GetModeParameter('j');
 137                                                 parameter = ConvToStr(njoins) + ":" +ConvToStr(nsecs);
 138                                                 if (cur_param == parameter)
 139                                                 {
 140                                                         // mode params match
 141                                                         return MODEACTION_DENY;
 142                                                 }
 143                                                 else
 144                                                 {
 145                                                         // new mode param, replace old with new
 146                                                         if ((nsecs > 0) && (njoins > 0))
 147                                                         {
 148                                                                 f = new joinfloodsettings(nsecs, njoins);
 149                                                                 ext.set(channel, f);
 150                                                                 channel->SetModeParam('j', parameter);
 151                                                                 return MODEACTION_ALLOW;
 152                                                         }
 153                                                         else
 154                                                         {
 155                                                                 return MODEACTION_DENY;
 156                                                         }
 157                                                 }
 158                                         }
 159                                 }
 160                         }
 161                         else
 162                         {
 163                                 source->WriteNumeric(608, "%s %s :Invalid flood parameter",source->nick.c_str(),channel->name.c_str());
 164                                 return MODEACTION_DENY;
 165                         }
 166                 }
 167                 else
 168                 {
 169                         joinfloodsettings* f = ext.get(channel);
 170                         if (f)
 171                         {
 172                                 ext.unset(channel);
 173                                 channel->SetModeParam('j', "");
 174                                 return MODEACTION_ALLOW;
 175                         }
 176                 }
 177                 return MODEACTION_DENY;
 178         }
 179 };
 180
 181 class ModuleJoinFlood : public Module
 182 {
 183
 184         JoinFlood jf;
 185
 186  public:
 187
 188         ModuleJoinFlood()
 189                 : jf(this)
 190         {
 191
 192                 if (!ServerInstance->Modes->AddMode(&jf))
 193                         throw ModuleException("Could not add new modes!");
 194                 ServerInstance->Extensions.Register(&jf.ext);
 195                 Implementation eventlist[] = { I_OnUserPreJoin, I_OnUserJoin };
 196                 ServerInstance->Modules->Attach(eventlist, this, 2);
 197         }
 198
 199         ModResult OnUserPreJoin(User* user, Channel* chan, const char* cname, std::string &privs, const std::string &keygiven)
 200         {
 201                 if (chan)
 202                 {
 203                         joinfloodsettings *f = jf.ext.get(chan);
 204                         if (f && f->islocked())
 205                         {
 206                                 user->WriteNumeric(609, "%s %s :This channel is temporarily unavailable (+j). Please try again later.",user->nick.c_str(),chan->name.c_str());
 207                                 return MOD_RES_DENY;
 208                         }
 209                 }
 210                 return MOD_RES_PASSTHRU;
 211         }
 212
 213         void OnUserJoin(Membership* memb, bool sync, bool created, CUList& excepts)
 214         {
 215                 /* We arent interested in JOIN events caused by a network burst */
 216                 if (sync)
 217                         return;
 218
 219                 joinfloodsettings *f = jf.ext.get(memb->chan);
 220
 221                 /* But all others are OK */
 222                 if (f)
 223                 {
 224                         f->addjoin();
 225                         if (f->shouldlock())
 226                         {
 227                                 f->clear();
 228                                 f->lock();
 229                                 memb->chan->WriteChannelWithServ((char*)ServerInstance->Config->ServerName.c_str(), "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);
 230                         }
 231                 }
 232         }
 233
 234         ~ModuleJoinFlood()
 235         {
 236         }
 237
 238         Version GetVersion()
 239         {
 240                 return Version("Provides channel mode +j (join flood protection)", VF_COMMON | VF_VENDOR);
 241         }
 242 };
 243
 244 MODULE_INIT(ModuleJoinFlood)