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) : ModeHandler(Instance, '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         bool CheckTimeStamp(time_t theirs, time_t ours, const std::string &their_param, const std::string &our_param, Channel* channel)
 105         {
 106                 /* When TS is equal, the alphabetically later one wins */
 107                 return (their_param < our_param);
 108         }
 109
 110         ModeAction OnModeChange(User* source, User* dest, Channel* channel, std::string &parameter, bool adding, bool)
 111         {
 112                 nickfloodsettings* dummy;
 113
 114                 if (adding)
 115                 {
 116                         char ndata[MAXBUF];
 117                         char* data = ndata;
 118                         strlcpy(ndata,parameter.c_str(),MAXBUF);
 119                         char* nicks = data;
 120                         char* secs = NULL;
 121                         while (*data)
 122                         {
 123                                 if (*data == ':')
 124                                 {
 125                                         *data = 0;
 126                                         data++;
 127                                         secs = data;
 128                                         break;
 129                                 }
 130                                 else data++;
 131                         }
 132                         if (secs)
 133
 134                         {
 135                                 /* Set up the flood parameters for this channel */
 136                                 int nnicks = atoi(nicks);
 137                                 int nsecs = atoi(secs);
 138                                 if ((nnicks<1) || (nsecs<1))
 139                                 {
 140                                         source->WriteNumeric(608, "%s %s :Invalid flood parameter",source->nick.c_str(),channel->name.c_str());
 141                                         parameter.clear();
 142                                         return MODEACTION_DENY;
 143                                 }
 144                                 else
 145                                 {
 146                                         if (!channel->GetExt("nickflood", dummy))
 147                                         {
 148                                                 parameter = ConvToStr(nnicks) + ":" +ConvToStr(nsecs);
 149                                                 nickfloodsettings *f = new nickfloodsettings(ServerInstance, nsecs, nnicks);
 150                                                 channel->Extend("nickflood", f);
 151                                                 channel->SetModeParam('F', parameter);
 152                                                 return MODEACTION_ALLOW;
 153                                         }
 154                                         else
 155                                         {
 156                                                 std::string cur_param = channel->GetModeParameter('F');
 157                                                 parameter = ConvToStr(nnicks) + ":" +ConvToStr(nsecs);
 158                                                 if (cur_param == parameter)
 159                                                 {
 160                                                         // mode params match
 161                                                         return MODEACTION_DENY;
 162                                                 }
 163                                                 else
 164                                                 {
 165                                                         // new mode param, replace old with new
 166                                                         if ((nsecs > 0) && (nnicks > 0))
 167                                                         {
 168                                                                 nickfloodsettings* f;
 169                                                                 channel->GetExt("nickflood", f);
 170                                                                 delete f;
 171                                                                 f = new nickfloodsettings(ServerInstance, nsecs, nnicks);
 172                                                                 channel->Shrink("nickflood");
 173                                                                 channel->Extend("nickflood", f);
 174                                                                 channel->SetModeParam('F', parameter);
 175                                                                 return MODEACTION_ALLOW;
 176                                                         }
 177                                                         else
 178                                                         {
 179                                                                 return MODEACTION_DENY;
 180                                                         }
 181                                                 }
 182                                         }
 183                                 }
 184                         }
 185                         else
 186                         {
 187                                 source->WriteNumeric(608, "%s %s :Invalid flood parameter",source->nick.c_str(),channel->name.c_str());
 188                                 return MODEACTION_DENY;
 189                         }
 190                 }
 191                 else
 192                 {
 193                         if (channel->GetExt("nickflood", dummy))
 194                         {
 195                                 nickfloodsettings *f;
 196                                 channel->GetExt("nickflood", f);
 197                                 delete f;
 198                                 channel->Shrink("nickflood");
 199                                 channel->SetModeParam('F', "");
 200                                 return MODEACTION_ALLOW;
 201                         }
 202                 }
 203                 return MODEACTION_DENY;
 204         }
 205 };
 206
 207 class ModuleNickFlood : public Module
 208 {
 209         NickFlood* jf;
 210
 211  public:
 212
 213         ModuleNickFlood(InspIRCd* Me)
 214                 : Module(Me)
 215         {
 216
 217                 jf = new NickFlood(ServerInstance);
 218                 if (!ServerInstance->Modes->AddMode(jf))
 219                         throw ModuleException("Could not add new modes!");
 220                 Implementation eventlist[] = { I_OnChannelDelete, I_OnUserPreNick, I_OnUserPostNick };
 221                 ServerInstance->Modules->Attach(eventlist, this, 3);
 222         }
 223
 224         virtual int OnUserPreNick(User* user, const std::string &newnick)
 225         {
 226                 if (isdigit(newnick[0])) /* allow switches to UID */
 227                         return 0;
 228
 229                 for (UCListIter i = user->chans.begin(); i != user->chans.end(); i++)
 230                 {
 231                         Channel *channel = i->first;
 232
 233                         nickfloodsettings *f;
 234                         if (channel->GetExt("nickflood", f))
 235                         {
 236                                 if (CHANOPS_EXEMPT(ServerInstance, 'F') && channel->GetStatus(user) == STATUS_OP)
 237                                         continue;
 238
 239                                 if (f->islocked())
 240                                 {
 241                                         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);
 242                                         return 1;
 243                                 }
 244
 245                                 if (f->shouldlock())
 246                                 {
 247                                         f->clear();
 248                                         f->lock();
 249                                         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);
 250                                         return 1;
 251                                 }
 252                         }
 253                 }
 254
 255                 return 0;
 256         }
 257
 258         /*
 259          * 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.
 260          */
 261         virtual void OnUserPostNick(User* user, const std::string oldnick)
 262         {
 263                 if (isdigit(user->nick[0])) /* allow switches to UID */
 264                         return;
 265
 266                 for (UCListIter i = user->chans.begin(); i != user->chans.end(); ++i)
 267                 {
 268                         Channel *channel = i->first;
 269
 270                         nickfloodsettings *f;
 271                         if (channel->GetExt("nickflood", f))
 272                         {
 273                                 if (CHANOPS_EXEMPT(ServerInstance, 'F') && channel->GetStatus(user) == STATUS_OP)
 274                                         return;
 275
 276                                 /* moved this here to avoid incrementing the counter for nick
 277                                  * changes that are denied for some other reason (bans, +N, etc.)
 278                                  * per bug #874.
 279                                  */
 280                                 f->addnick();
 281                         }
 282                 }
 283                 return;
 284         }
 285
 286         void OnChannelDelete(Channel* chan)
 287         {
 288                 nickfloodsettings *f;
 289                 if (chan->GetExt("nickflood",f))
 290                 {
 291                         delete f;
 292                         chan->Shrink("nickflood");
 293                 }
 294         }
 295
 296
 297         virtual ~ModuleNickFlood()
 298         {
 299                 ServerInstance->Modes->DelMode(jf);
 300                 delete jf;
 301         }
 302
 303         virtual Version GetVersion()
 304         {
 305                 return Version("$Id$", VF_COMMON | VF_VENDOR, API_VERSION);
 306         }
 307 };
 308
 309 MODULE_INIT(ModuleNickFlood)