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         SimpleExtItem<nickfloodsettings> ext;
  94         NickFlood(InspIRCd* Instance, Module* Creator) : ModeHandler(Creator, 'F', PARAM_SETONLY, MODETYPE_CHANNEL),
  95                 ext("nickflood", Creator) { }
  96
  97         ModePair ModeSet(User* source, User* dest, Channel* channel, const std::string &parameter)
  98         {
  99                 nickfloodsettings* x = ext.get(channel);
 100                 if (x)
 101                         return std::make_pair(true, ConvToStr(x->nicks)+":"+ConvToStr(x->secs));
 102                 else
 103                         return std::make_pair(false, parameter);
 104         }
 105
 106         ModeAction OnModeChange(User* source, User* dest, Channel* channel, std::string &parameter, bool adding)
 107         {
 108                 nickfloodsettings *f = ext.get(channel);
 109                 if (adding)
 110                 {
 111                         char ndata[MAXBUF];
 112                         char* data = ndata;
 113                         strlcpy(ndata,parameter.c_str(),MAXBUF);
 114                         char* nicks = data;
 115                         char* secs = NULL;
 116                         while (*data)
 117                         {
 118                                 if (*data == ':')
 119                                 {
 120                                         *data = 0;
 121                                         data++;
 122                                         secs = data;
 123                                         break;
 124                                 }
 125                                 else data++;
 126                         }
 127                         if (secs)
 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 (!f)
 141                                         {
 142                                                 parameter = ConvToStr(nnicks) + ":" +ConvToStr(nsecs);
 143                                                 f = new nickfloodsettings(ServerInstance, nsecs, nnicks);
 144                                                 ext.set(channel, 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                                                                 f = new nickfloodsettings(ServerInstance, nsecs, nnicks);
 163                                                                 ext.set(channel, f);
 164                                                                 channel->SetModeParam('F', parameter);
 165                                                                 return MODEACTION_ALLOW;
 166                                                         }
 167                                                         else
 168                                                         {
 169                                                                 return MODEACTION_DENY;
 170                                                         }
 171                                                 }
 172                                         }
 173                                 }
 174                         }
 175                         else
 176                         {
 177                                 source->WriteNumeric(608, "%s %s :Invalid flood parameter",source->nick.c_str(),channel->name.c_str());
 178                                 return MODEACTION_DENY;
 179                         }
 180                 }
 181                 else
 182                 {
 183                         if (f)
 184                         {
 185                                 ext.unset(channel);
 186                                 channel->SetModeParam('F', "");
 187                                 return MODEACTION_ALLOW;
 188                         }
 189                 }
 190                 return MODEACTION_DENY;
 191         }
 192 };
 193
 194 class ModuleNickFlood : public Module
 195 {
 196         NickFlood nf;
 197
 198  public:
 199
 200         ModuleNickFlood(InspIRCd* Me)
 201                 : Module(Me), nf(Me, this)
 202         {
 203                 if (!ServerInstance->Modes->AddMode(&nf))
 204                         throw ModuleException("Could not add new modes!");
 205                 Extensible::Register(&nf.ext);
 206                 Implementation eventlist[] = { I_OnUserPreNick, I_OnUserPostNick };
 207                 ServerInstance->Modules->Attach(eventlist, this, 2);
 208         }
 209
 210         ModResult OnUserPreNick(User* user, const std::string &newnick)
 211         {
 212                 if (isdigit(newnick[0])) /* allow switches to UID */
 213                         return MOD_RES_PASSTHRU;
 214
 215                 for (UCListIter i = user->chans.begin(); i != user->chans.end(); i++)
 216                 {
 217                         Channel *channel = *i;
 218
 219                         nickfloodsettings *f = nf.ext.get(channel);
 220                         if (f)
 221                         {
 222                                 if (CHANOPS_EXEMPT(ServerInstance, 'F') && channel->GetPrefixValue(user) == OP_VALUE)
 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, "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
 256                         nickfloodsettings *f = nf.ext.get(channel);
 257                         if (f)
 258                         {
 259                                 if (CHANOPS_EXEMPT(ServerInstance, 'F') && channel->GetPrefixValue(user) == OP_VALUE)
 260                                         return;
 261
 262                                 /* moved this here to avoid incrementing the counter for nick
 263                                  * changes that are denied for some other reason (bans, +N, etc.)
 264                                  * per bug #874.
 265                                  */
 266                                 f->addnick();
 267                         }
 268                 }
 269                 return;
 270         }
 271
 272         ~ModuleNickFlood()
 273         {
 274                 ServerInstance->Modes->DelMode(&nf);
 275         }
 276
 277         Version GetVersion()
 278         {
 279                 return Version("Channel mode F - nick flood protection", VF_COMMON | VF_VENDOR);
 280         }
 281 };
 282
 283 MODULE_INIT(ModuleNickFlood)