src/modules/m_nickflood.cpp

   1 /*
   2  * InspIRCd -- Internet Relay Chat Daemon
   3  *
   4  *   Copyright (C) 2009 Daniel De Graaf <danieldg@inspircd.org>
   5  *   Copyright (C) 2007, 2009 Robin Burchell <robin+git@viroteck.net>
   6  *
   7  * This file is part of InspIRCd.  InspIRCd is free software: you can
   8  * redistribute it and/or modify it under the terms of the GNU General Public
   9  * License as published by the Free Software Foundation, version 2.
  10  *
  11  * This program is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  13  * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
  14  * details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20
  21 #include "inspircd.h"
  22
  23 /** Holds settings and state associated with channel mode +F
  24  */
  25 class nickfloodsettings
  26 {
  27  public:
  28         unsigned int secs;
  29         unsigned int nicks;
  30         time_t reset;
  31         time_t unlocktime;
  32         unsigned int counter;
  33
  34         nickfloodsettings(unsigned int b, unsigned int c)
  35                 : secs(b), nicks(c), unlocktime(0), counter(0)
  36         {
  37                 reset = ServerInstance->Time() + secs;
  38         }
  39
  40         void addnick()
  41         {
  42                 if (ServerInstance->Time() > reset)
  43                 {
  44                         counter = 1;
  45                         reset = ServerInstance->Time() + secs;
  46                 }
  47                 else
  48                         counter++;
  49         }
  50
  51         bool shouldlock()
  52         {
  53                 /* XXX HACK: using counter + 1 here now to allow the counter to only be incremented
  54                  * on successful nick changes; this will be checked before the counter is
  55                  * incremented.
  56                  */
  57                 return ((ServerInstance->Time() <= reset) && (counter == this->nicks));
  58         }
  59
  60         void clear()
  61         {
  62                 counter = 0;
  63         }
  64
  65         bool islocked()
  66         {
  67                 if (ServerInstance->Time() > unlocktime)
  68                         unlocktime = 0;
  69
  70                 return (unlocktime != 0);
  71         }
  72
  73         void lock()
  74         {
  75                 unlocktime = ServerInstance->Time() + 60;
  76         }
  77 };
  78
  79 /** Handles channel mode +F
  80  */
  81 class NickFlood : public ParamMode<NickFlood, SimpleExtItem<nickfloodsettings> >
  82 {
  83  public:
  84         NickFlood(Module* Creator)
  85                 : ParamMode<NickFlood, SimpleExtItem<nickfloodsettings> >(Creator, "nickflood", 'F')
  86         {
  87         }
  88
  89         ModeAction OnSet(User* source, Channel* channel, std::string& parameter)
  90         {
  91                 std::string::size_type colon = parameter.find(':');
  92                 if ((colon == std::string::npos) || (parameter.find('-') != std::string::npos))
  93                 {
  94                         source->WriteNumeric(608, channel->name, "Invalid flood parameter");
  95                         return MODEACTION_DENY;
  96                 }
  97
  98                 /* Set up the flood parameters for this channel */
  99                 unsigned int nnicks = ConvToInt(parameter.substr(0, colon));
 100                 unsigned int nsecs = ConvToInt(parameter.substr(colon+1));
 101
 102                 if ((nnicks<1) || (nsecs<1))
 103                 {
 104                         source->WriteNumeric(608, channel->name, "Invalid flood parameter");
 105                         return MODEACTION_DENY;
 106                 }
 107
 108                 ext.set(channel, new nickfloodsettings(nsecs, nnicks));
 109                 return MODEACTION_ALLOW;
 110         }
 111
 112         void SerializeParam(Channel* chan, const nickfloodsettings* nfs, std::string& out)
 113         {
 114                 out.append(ConvToStr(nfs->nicks)).push_back(':');
 115                 out.append(ConvToStr(nfs->secs));
 116         }
 117 };
 118
 119 class ModuleNickFlood : public Module
 120 {
 121         NickFlood nf;
 122
 123  public:
 124         ModuleNickFlood()
 125                 : nf(this)
 126         {
 127         }
 128
 129         ModResult OnUserPreNick(LocalUser* user, const std::string& newnick) CXX11_OVERRIDE
 130         {
 131                 for (User::ChanList::iterator i = user->chans.begin(); i != user->chans.end(); i++)
 132                 {
 133                         Channel* channel = (*i)->chan;
 134                         ModResult res;
 135
 136                         nickfloodsettings *f = nf.ext.get(channel);
 137                         if (f)
 138                         {
 139                                 res = ServerInstance->OnCheckExemption(user,channel,"nickflood");
 140                                 if (res == MOD_RES_ALLOW)
 141                                         continue;
 142
 143                                 if (f->islocked())
 144                                 {
 145                                         user->WriteNumeric(ERR_CANTCHANGENICK, InspIRCd::Format("%s has been locked for nickchanges for 60 seconds because there have been more than %u nick changes in %u seconds", channel->name.c_str(), f->nicks, f->secs));
 146                                         return MOD_RES_DENY;
 147                                 }
 148
 149                                 if (f->shouldlock())
 150                                 {
 151                                         f->clear();
 152                                         f->lock();
 153                                         channel->WriteChannelWithServ((char*)ServerInstance->Config->ServerName.c_str(), "NOTICE %s :No nick changes are allowed for 60 seconds because there have been more than %u nick changes in %u seconds.", channel->name.c_str(), f->nicks, f->secs);
 154                                         return MOD_RES_DENY;
 155                                 }
 156                         }
 157                 }
 158
 159                 return MOD_RES_PASSTHRU;
 160         }
 161
 162         /*
 163          * 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.
 164          */
 165         void OnUserPostNick(User* user, const std::string &oldnick) CXX11_OVERRIDE
 166         {
 167                 if (isdigit(user->nick[0])) /* allow switches to UID */
 168                         return;
 169
 170                 for (User::ChanList::iterator i = user->chans.begin(); i != user->chans.end(); ++i)
 171                 {
 172                         Channel* channel = (*i)->chan;
 173                         ModResult res;
 174
 175                         nickfloodsettings *f = nf.ext.get(channel);
 176                         if (f)
 177                         {
 178                                 res = ServerInstance->OnCheckExemption(user,channel,"nickflood");
 179                                 if (res == MOD_RES_ALLOW)
 180                                         return;
 181
 182                                 /* moved this here to avoid incrementing the counter for nick
 183                                  * changes that are denied for some other reason (bans, +N, etc.)
 184                                  * per bug #874.
 185                                  */
 186                                 f->addnick();
 187                         }
 188                 }
 189         }
 190
 191         Version GetVersion() CXX11_OVERRIDE
 192         {
 193                 return Version("Channel mode F - nick flood protection", VF_VENDOR);
 194         }
 195 };
 196
 197 MODULE_INIT(ModuleNickFlood)