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
  21 {
  22  public:
  23         int secs;
  24         int nicks;
  25         time_t reset;
  26         time_t unlocktime;
  27         int counter;
  28         bool locked;
  29
  30         nickfloodsettings(int b, int c) : secs(b), nicks(c)
  31         {
  32                 reset = ServerInstance->Time() + secs;
  33                 counter = 0;
  34                 locked = false;
  35         };
  36
  37         void addnick()
  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                 /* XXX HACK: using counter + 1 here now to allow the counter to only be incremented
  50                  * on successful nick changes; this will be checked before the counter is
  51                  * incremented.
  52                  */
  53                 return (counter + 1 >= this->nicks);
  54         }
  55
  56         void clear()
  57         {
  58                 counter = 0;
  59         }
  60
  61         bool islocked()
  62         {
  63                 if (locked)
  64                 {
  65                         if (ServerInstance->Time() > unlocktime)
  66                         {
  67                                 locked = false;
  68                                 return false;
  69                         }
  70                         else
  71                         {
  72                                 return true;
  73                         }
  74                 }
  75                 return false;
  76         }
  77
  78         void lock()
  79         {
  80                 locked = true;
  81                 unlocktime = ServerInstance->Time() + 60;
  82         }
  83
  84 };
  85
  86 /** Handles channel mode +j
  87  */
  88 class NickFlood : public ModeHandler
  89 {
  90  public:
  91         SimpleExtItem<nickfloodsettings> ext;
  92         NickFlood(Module* Creator) : ModeHandler(Creator, "nickflood", 'F', PARAM_SETONLY, MODETYPE_CHANNEL),
  93                 ext("nickflood", Creator) { }
  94
  95         ModePair ModeSet(User* source, User* dest, Channel* channel, const std::string &parameter)
  96         {
  97                 nickfloodsettings* x = ext.get(channel);
  98                 if (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 *f = ext.get(channel);
 107                 if (adding)
 108                 {
 109                         char ndata[MAXBUF];
 110                         char* data = ndata;
 111                         strlcpy(ndata,parameter.c_str(),MAXBUF);
 112                         char* nicks = data;
 113                         char* secs = NULL;
 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 nnicks = atoi(nicks);
 129                                 int nsecs = atoi(secs);
 130                                 if ((nnicks<1) || (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 = ConvToStr(nnicks) + ":" +ConvToStr(nsecs);
 141                                                 f = new nickfloodsettings(nsecs, nnicks);
 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 = ConvToStr(nnicks) + ":" +ConvToStr(nsecs);
 150                                                 if (cur_param == parameter)
 151                                                 {
 152                                                         // mode params match
 153                                                         return MODEACTION_DENY;
 154                                                 }
 155                                                 else
 156                                                 {
 157                                                         // new mode param, replace old with new
 158                                                         if ((nsecs > 0) && (nnicks > 0))
 159                                                         {
 160                                                                 f = new nickfloodsettings(nsecs, nnicks);
 161                                                                 ext.set(channel, f);
 162                                                                 channel->SetModeParam('F', parameter);
 163                                                                 return MODEACTION_ALLOW;
 164                                                         }
 165                                                         else
 166                                                         {
 167                                                                 return MODEACTION_DENY;
 168                                                         }
 169                                                 }
 170                                         }
 171                                 }
 172                         }
 173                         else
 174                         {
 175                                 source->WriteNumeric(608, "%s %s :Invalid flood parameter",source->nick.c_str(),channel->name.c_str());
 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                 return MODEACTION_DENY;
 189         }
 190 };
 191
 192 class ModuleNickFlood : public Module
 193 {
 194         NickFlood nf;
 195
 196  public:
 197
 198         ModuleNickFlood()
 199                 : nf(this)
 200         {
 201                 if (!ServerInstance->Modes->AddMode(&nf))
 202                         throw ModuleException("Could not add new modes!");
 203                 ServerInstance->Extensions.Register(&nf.ext);
 204                 Implementation eventlist[] = { I_OnUserPreNick, I_OnUserPostNick };
 205                 ServerInstance->Modules->Attach(eventlist, this, 2);
 206         }
 207
 208         ModResult OnUserPreNick(User* user, const std::string &newnick)
 209         {
 210                 if (isdigit(newnick[0])) /* allow switches to UID */
 211                         return MOD_RES_PASSTHRU;
 212
 213                 for (UCListIter i = user->chans.begin(); i != user->chans.end(); i++)
 214                 {
 215                         Channel *channel = *i;
 216                         ModResult res;
 217
 218                         nickfloodsettings *f = nf.ext.get(channel);
 219                         if (f)
 220                         {
 221                                 FIRST_MOD_RESULT(OnChannelRestrictionApply, res, (user,channel,"nickflood"));
 222                                 if (res == MOD_RES_ALLOW)
 223                                         continue;
 224
 225                                 if (f->islocked())
 226                                 {
 227                                         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);
 228                                         return MOD_RES_DENY;
 229                                 }
 230
 231                                 if (f->shouldlock())
 232                                 {
 233                                         f->clear();
 234                                         f->lock();
 235                                         channel->WriteChannelWithServ((char*)ServerInstance->Config->ServerName.c_str(), "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);
 236                                         return MOD_RES_DENY;
 237                                 }
 238                         }
 239                 }
 240
 241                 return MOD_RES_PASSTHRU;
 242         }
 243
 244         /*
 245          * 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.
 246          */
 247         void OnUserPostNick(User* user, const std::string &oldnick)
 248         {
 249                 if (isdigit(user->nick[0])) /* allow switches to UID */
 250                         return;
 251
 252                 for (UCListIter i = user->chans.begin(); i != user->chans.end(); ++i)
 253                 {
 254                         Channel *channel = *i;
 255                         ModResult res;
 256
 257                         nickfloodsettings *f = nf.ext.get(channel);
 258                         if (f)
 259                         {
 260                                 FIRST_MOD_RESULT(OnChannelRestrictionApply, res, (user,channel,"nickflood"));
 261                                 if (res == MOD_RES_ALLOW)
 262                                         return;
 263
 264                                 /* moved this here to avoid incrementing the counter for nick
 265                                  * changes that are denied for some other reason (bans, +N, etc.)
 266                                  * per bug #874.
 267                                  */
 268                                 f->addnick();
 269                         }
 270                 }
 271                 return;
 272         }
 273
 274         ~ModuleNickFlood()
 275         {
 276         }
 277
 278         Version GetVersion()
 279         {
 280                 return Version("Channel mode F - nick flood protection", VF_COMMON | VF_VENDOR);
 281         }
 282 };
 283
 284 MODULE_INIT(ModuleNickFlood)