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 // The number of seconds nickname changing will be blocked for.
  24 static unsigned int duration;
  25
  26 /** Holds settings and state associated with channel mode +F
  27  */
  28 class nickfloodsettings
  29 {
  30  public:
  31         unsigned int secs;
  32         unsigned int nicks;
  33         time_t reset;
  34         time_t unlocktime;
  35         unsigned int counter;
  36
  37         nickfloodsettings(unsigned int b, unsigned int c)
  38                 : secs(b), nicks(c), unlocktime(0), counter(0)
  39         {
  40                 reset = ServerInstance->Time() + secs;
  41         }
  42
  43         void addnick()
  44         {
  45                 if (ServerInstance->Time() > reset)
  46                 {
  47                         counter = 1;
  48                         reset = ServerInstance->Time() + secs;
  49                 }
  50                 else
  51                         counter++;
  52         }
  53
  54         bool shouldlock()
  55         {
  56                 /* XXX HACK: using counter + 1 here now to allow the counter to only be incremented
  57                  * on successful nick changes; this will be checked before the counter is
  58                  * incremented.
  59                  */
  60                 return ((ServerInstance->Time() <= reset) && (counter == this->nicks));
  61         }
  62
  63         void clear()
  64         {
  65                 counter = 0;
  66         }
  67
  68         bool islocked()
  69         {
  70                 if (ServerInstance->Time() > unlocktime)
  71                         unlocktime = 0;
  72
  73                 return (unlocktime != 0);
  74         }
  75
  76         void lock()
  77         {
  78                 unlocktime = ServerInstance->Time() + duration;
  79         }
  80 };
  81
  82 /** Handles channel mode +F
  83  */
  84 class NickFlood : public ParamMode<NickFlood, SimpleExtItem<nickfloodsettings> >
  85 {
  86  public:
  87         NickFlood(Module* Creator)
  88                 : ParamMode<NickFlood, SimpleExtItem<nickfloodsettings> >(Creator, "nickflood", 'F')
  89         {
  90         }
  91
  92         ModeAction OnSet(User* source, Channel* channel, std::string& parameter)
  93         {
  94                 std::string::size_type colon = parameter.find(':');
  95                 if ((colon == std::string::npos) || (parameter.find('-') != std::string::npos))
  96                 {
  97                         source->WriteNumeric(608, channel->name, "Invalid flood parameter");
  98                         return MODEACTION_DENY;
  99                 }
 100
 101                 /* Set up the flood parameters for this channel */
 102                 unsigned int nnicks = ConvToInt(parameter.substr(0, colon));
 103                 unsigned int nsecs = ConvToInt(parameter.substr(colon+1));
 104
 105                 if ((nnicks<1) || (nsecs<1))
 106                 {
 107                         source->WriteNumeric(608, channel->name, "Invalid flood parameter");
 108                         return MODEACTION_DENY;
 109                 }
 110
 111                 ext.set(channel, new nickfloodsettings(nsecs, nnicks));
 112                 return MODEACTION_ALLOW;
 113         }
 114
 115         void SerializeParam(Channel* chan, const nickfloodsettings* nfs, std::string& out)
 116         {
 117                 out.append(ConvToStr(nfs->nicks)).push_back(':');
 118                 out.append(ConvToStr(nfs->secs));
 119         }
 120 };
 121
 122 class ModuleNickFlood : public Module
 123 {
 124         NickFlood nf;
 125
 126  public:
 127         ModuleNickFlood()
 128                 : nf(this)
 129         {
 130         }
 131
 132         void ReadConfig(ConfigStatus&) CXX11_OVERRIDE
 133         {
 134                 ConfigTag* tag = ServerInstance->Config->ConfValue("nickflood");
 135                 duration = tag->getDuration("duration", 60, 10, 600);
 136         }
 137
 138         ModResult OnUserPreNick(LocalUser* user, const std::string& newnick) CXX11_OVERRIDE
 139         {
 140                 for (User::ChanList::iterator i = user->chans.begin(); i != user->chans.end(); i++)
 141                 {
 142                         Channel* channel = (*i)->chan;
 143                         ModResult res;
 144
 145                         nickfloodsettings *f = nf.ext.get(channel);
 146                         if (f)
 147                         {
 148                                 res = ServerInstance->OnCheckExemption(user,channel,"nickflood");
 149                                 if (res == MOD_RES_ALLOW)
 150                                         continue;
 151
 152                                 if (f->islocked())
 153                                 {
 154                                         user->WriteNumeric(ERR_CANTCHANGENICK, InspIRCd::Format("%s has been locked for nickchanges for %u seconds because there have been more than %u nick changes in %u seconds", channel->name.c_str(), duration, f->nicks, f->secs));
 155                                         return MOD_RES_DENY;
 156                                 }
 157
 158                                 if (f->shouldlock())
 159                                 {
 160                                         f->clear();
 161                                         f->lock();
 162                                         channel->WriteNotice(InspIRCd::Format("No nick changes are allowed for %u seconds because there have been more than %u nick changes in %u seconds.", duration, f->nicks, f->secs));
 163                                         return MOD_RES_DENY;
 164                                 }
 165                         }
 166                 }
 167
 168                 return MOD_RES_PASSTHRU;
 169         }
 170
 171         /*
 172          * 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.
 173          */
 174         void OnUserPostNick(User* user, const std::string &oldnick) CXX11_OVERRIDE
 175         {
 176                 if (isdigit(user->nick[0])) /* allow switches to UID */
 177                         return;
 178
 179                 for (User::ChanList::iterator i = user->chans.begin(); i != user->chans.end(); ++i)
 180                 {
 181                         Channel* channel = (*i)->chan;
 182                         ModResult res;
 183
 184                         nickfloodsettings *f = nf.ext.get(channel);
 185                         if (f)
 186                         {
 187                                 res = ServerInstance->OnCheckExemption(user,channel,"nickflood");
 188                                 if (res == MOD_RES_ALLOW)
 189                                         return;
 190
 191                                 /* moved this here to avoid incrementing the counter for nick
 192                                  * changes that are denied for some other reason (bans, +N, etc.)
 193                                  * per bug #874.
 194                                  */
 195                                 f->addnick();
 196                         }
 197                 }
 198         }
 199
 200         Version GetVersion() CXX11_OVERRIDE
 201         {
 202                 return Version("Channel mode F - nick flood protection", VF_VENDOR);
 203         }
 204 };
 205
 206 MODULE_INIT(ModuleNickFlood)