src/modules/m_nickflood.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 +F (nick flood protection) */
  17
  18 /** Holds settings and state associated with channel mode +F
  19  */
  20 class nickfloodsettings : public classbase
  21 {
  22  private:
  23         InspIRCd* ServerInstance;
  24  public:
  25         int secs;
  26         int nicks;
  27         time_t reset;
  28         time_t unlocktime;
  29         int counter;
  30         bool locked;
  31
  32         nickfloodsettings(InspIRCd *Instance, int b, int c) : ServerInstance(Instance), secs(b), nicks(c)
  33         {
  34                 reset = Instance->Time() + secs;
  35                 counter = 0;
  36                 locked = false;
  37         };
  38
  39         void addnick()
  40         {
  41                 counter++;
  42                 if (ServerInstance->Time() > reset)
  43                 {
  44                         counter = 0;
  45                         reset = ServerInstance->Time() + secs;
  46                 }
  47         }
  48
  49         bool shouldlock()
  50         {
  51                 /* XXX HACK: using counter + 1 here now to allow the counter to only be incremented
  52                  * on successful nick changes; this will be checked before the counter is
  53                  * incremented.
  54                  */
  55                 return (counter + 1 >= this->nicks);
  56         }
  57
  58         void clear()
  59         {
  60                 counter = 0;
  61         }
  62
  63         bool islocked()
  64         {
  65                 if (locked)
  66                 {
  67                         if (ServerInstance->Time() > unlocktime)
  68                         {
  69                                 locked = false;
  70                                 return false;
  71                         }
  72                         else
  73                         {
  74                                 return true;
  75                         }
  76                 }
  77                 return false;
  78         }
  79
  80         void lock()
  81         {
  82                 locked = true;
  83                 unlocktime = ServerInstance->Time() + 60;
  84         }
  85
  86 };
  87
  88 /** Handles channel mode +j
  89  */
  90 class NickFlood : public ModeHandler
  91 {
  92  public:
  93         NickFlood(InspIRCd* Instance, Module* Creator) : ModeHandler(Instance, Creator, 'F', 1, 0, false, MODETYPE_CHANNEL, false) { }
  94
  95         ModePair ModeSet(User* source, User* dest, Channel* channel, const std::string &parameter)
  96         {
  97                 nickfloodsettings* x;
  98                 if (channel->GetExt("nickflood",x))
  99                         return std::make_pair(true, ConvToStr(x->nicks)+":"+ConvToStr(x->secs));
 100                 else
 101                         return std::make_pair(false, parameter);
 102         }
 103
 104         ModeAction OnModeChange(User* source, User* dest, Channel* channel, std::string &parameter, bool adding)
 105         {
 106                 nickfloodsettings* dummy;
 107
 108                 if (adding)
 109                 {
 110                         char ndata[MAXBUF];
 111                         char* data = ndata;
 112                         strlcpy(ndata,parameter.c_str(),MAXBUF);
 113                         char* nicks = data;
 114                         char* secs = NULL;
 115                         while (*data)
 116                         {
 117                                 if (*data == ':')
 118                                 {
 119                                         *data = 0;
 120                                         data++;
 121                                         secs = data;
 122                                         break;
 123                                 }
 124                                 else data++;
 125                         }
 126                         if (secs)
 127
 128                         {
 129                                 /* Set up the flood parameters for this channel */
 130                                 int nnicks = atoi(nicks);
 131                                 int nsecs = atoi(secs);
 132                                 if ((nnicks<1) || (nsecs<1))
 133                                 {
 134                                         source->WriteNumeric(608, "%s %s :Invalid flood parameter",source->nick.c_str(),channel->name.c_str());
 135                                         parameter.clear();
 136                                         return MODEACTION_DENY;
 137                                 }
 138                                 else
 139                                 {
 140                                         if (!channel->GetExt("nickflood", dummy))
 141                                         {
 142                                                 parameter = ConvToStr(nnicks) + ":" +ConvToStr(nsecs);
 143                                                 nickfloodsettings *f = new nickfloodsettings(ServerInstance, nsecs, nnicks);
 144                                                 channel->Extend("nickflood", f);
 145                                                 channel->SetModeParam('F', parameter);
 146                                                 return MODEACTION_ALLOW;
 147                                         }
 148                                         else
 149                                         {
 150                                                 std::string cur_param = channel->GetModeParameter('F');
 151                                                 parameter = ConvToStr(nnicks) + ":" +ConvToStr(nsecs);
 152                                                 if (cur_param == parameter)
 153                                                 {
 154                                                         // mode params match
 155                                                         return MODEACTION_DENY;
 156                                                 }
 157                                                 else
 158                                                 {
 159                                                         // new mode param, replace old with new
 160                                                         if ((nsecs > 0) && (nnicks > 0))
 161                                                         {
 162                                                                 nickfloodsettings* f;
 163                                                                 channel->GetExt("nickflood", f);
 164                                                                 delete f;
 165                                                                 f = new nickfloodsettings(ServerInstance, nsecs, nnicks);
 166                                                                 channel->Shrink("nickflood");
 167                                                                 channel->Extend("nickflood", f);
 168                                                                 channel->SetModeParam('F', parameter);
 169                                                                 return MODEACTION_ALLOW;
 170                                                         }
 171                                                         else
 172                                                         {
 173                                                                 return MODEACTION_DENY;
 174                                                         }
 175                                                 }
 176                                         }
 177                                 }
 178                         }
 179                         else
 180                         {
 181                                 source->WriteNumeric(608, "%s %s :Invalid flood parameter",source->nick.c_str(),channel->name.c_str());
 182                                 return MODEACTION_DENY;
 183                         }
 184                 }
 185                 else
 186                 {
 187                         if (channel->GetExt("nickflood", dummy))
 188                         {
 189                                 nickfloodsettings *f;
 190                                 channel->GetExt("nickflood", f);
 191                                 delete f;
 192                                 channel->Shrink("nickflood");
 193                                 channel->SetModeParam('F', "");
 194                                 return MODEACTION_ALLOW;
 195                         }
 196                 }
 197                 return MODEACTION_DENY;
 198         }
 199 };
 200
 201 class ModuleNickFlood : public Module
 202 {
 203         NickFlood jf;
 204
 205  public:
 206
 207         ModuleNickFlood(InspIRCd* Me)
 208                 : Module(Me), jf(Me, this)
 209         {
 210                 if (!ServerInstance->Modes->AddMode(&jf))
 211                         throw ModuleException("Could not add new modes!");
 212                 Implementation eventlist[] = { I_OnChannelDelete, I_OnUserPreNick, I_OnUserPostNick };
 213                 ServerInstance->Modules->Attach(eventlist, this, 3);
 214         }
 215
 216         virtual int OnUserPreNick(User* user, const std::string &newnick)
 217         {
 218                 if (isdigit(newnick[0])) /* allow switches to UID */
 219                         return 0;
 220
 221                 for (UCListIter i = user->chans.begin(); i != user->chans.end(); i++)
 222                 {
 223                         Channel *channel = i->first;
 224
 225                         nickfloodsettings *f;
 226                         if (channel->GetExt("nickflood", f))
 227                         {
 228                                 if (CHANOPS_EXEMPT(ServerInstance, 'F') && channel->GetStatus(user) == STATUS_OP)
 229                                         continue;
 230
 231                                 if (f->islocked())
 232                                 {
 233                                         user->WriteNumeric(447, "%s :%s has been locked for nickchanges for 60 seconds because there have been more than %d nick changes in %d seconds", user->nick.c_str(), channel->name.c_str(), f->nicks, f->secs);
 234                                         return 1;
 235                                 }
 236
 237                                 if (f->shouldlock())
 238                                 {
 239                                         f->clear();
 240                                         f->lock();
 241                                         channel->WriteChannelWithServ((char*)ServerInstance->Config->ServerName, "NOTICE %s :No nick changes are allowed for 60 seconds because there have been more than %d nick changes in %d seconds.", channel->name.c_str(), f->nicks, f->secs);
 242                                         return 1;
 243                                 }
 244                         }
 245                 }
 246
 247                 return 0;
 248         }
 249
 250         /*
 251          * XXX: HACK: We do the increment on the *POST* event here (instead of all together) because we have no way of knowing whether other modules would block a nickchange.
 252          */
 253         virtual void OnUserPostNick(User* user, const std::string &oldnick)
 254         {
 255                 if (isdigit(user->nick[0])) /* allow switches to UID */
 256                         return;
 257
 258                 for (UCListIter i = user->chans.begin(); i != user->chans.end(); ++i)
 259                 {
 260                         Channel *channel = i->first;
 261
 262                         nickfloodsettings *f;
 263                         if (channel->GetExt("nickflood", f))
 264                         {
 265                                 if (CHANOPS_EXEMPT(ServerInstance, 'F') && channel->GetStatus(user) == STATUS_OP)
 266                                         return;
 267
 268                                 /* moved this here to avoid incrementing the counter for nick
 269                                  * changes that are denied for some other reason (bans, +N, etc.)
 270                                  * per bug #874.
 271                                  */
 272                                 f->addnick();
 273                         }
 274                 }
 275                 return;
 276         }
 277
 278         void OnChannelDelete(Channel* chan)
 279         {
 280                 nickfloodsettings *f;
 281                 if (chan->GetExt("nickflood",f))
 282                 {
 283                         delete f;
 284                         chan->Shrink("nickflood");
 285                 }
 286         }
 287
 288
 289         virtual ~ModuleNickFlood()
 290         {
 291                 ServerInstance->Modes->DelMode(&jf);
 292         }
 293
 294         virtual Version GetVersion()
 295         {
 296                 return Version("$Id$", VF_COMMON | VF_VENDOR, API_VERSION);
 297         }
 298 };
 299
 300 MODULE_INIT(ModuleNickFlood)