src/modules/m_denychans.cpp

   1 /*
   2  * InspIRCd -- Internet Relay Chat Daemon
   3  *
   4  *   Copyright (C) 2019 Matt Schatz <genius3000@g3k.solutions>
   5  *   Copyright (C) 2013, 2018 Sadie Powell <sadie@witchery.services>
   6  *   Copyright (C) 2012-2013 Attila Molnar <attilamolnar@hush.com>
   7  *   Copyright (C) 2012 Robby <robby@chatbelgie.be>
   8  *   Copyright (C) 2009 Uli Schlachter <psychon@inspircd.org>
   9  *   Copyright (C) 2009 Daniel De Graaf <danieldg@inspircd.org>
  10  *   Copyright (C) 2008 Robin Burchell <robin+git@viroteck.net>
  11  *   Copyright (C) 2007 Dennis Friis <peavey@inspircd.org>
  12  *   Copyright (C) 2005, 2007, 2010 Craig Edwards <brain@inspircd.org>
  13  *
  14  * This file is part of InspIRCd.  InspIRCd is free software: you can
  15  * redistribute it and/or modify it under the terms of the GNU General Public
  16  * License as published by the Free Software Foundation, version 2.
  17  *
  18  * This program is distributed in the hope that it will be useful, but WITHOUT
  19  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  20  * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
  21  * details.
  22  *
  23  * You should have received a copy of the GNU General Public License
  24  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  25  */
  26
  27
  28 #include "inspircd.h"
  29
  30 enum
  31 {
  32         // InspIRCd-specific.
  33         ERR_BADCHANNEL = 926
  34 };
  35
  36 struct BadChannel
  37 {
  38         bool allowopers;
  39         std::string name;
  40         std::string reason;
  41         std::string redirect;
  42
  43         BadChannel(const std::string& Name, const std::string& Redirect, const std::string& Reason, bool AllowOpers)
  44                 : allowopers(AllowOpers)
  45                 , name(Name)
  46                 , reason(Reason)
  47                 , redirect(Redirect)
  48         {
  49         }
  50 };
  51
  52 typedef std::vector<BadChannel> BadChannels;
  53 typedef std::vector<std::string> GoodChannels;
  54
  55 class ModuleDenyChannels : public Module
  56 {
  57  private:
  58         BadChannels badchannels;
  59         GoodChannels goodchannels;
  60         UserModeReference antiredirectmode;
  61         ChanModeReference redirectmode;
  62
  63  public:
  64         ModuleDenyChannels()
  65                 : antiredirectmode(this, "antiredirect")
  66                 , redirectmode(this, "redirect")
  67         {
  68         }
  69
  70         void ReadConfig(ConfigStatus& status) CXX11_OVERRIDE
  71         {
  72                 GoodChannels goodchans;
  73                 ConfigTagList tags = ServerInstance->Config->ConfTags("goodchan");
  74                 for (ConfigIter iter = tags.first; iter != tags.second; ++iter)
  75                 {
  76                         ConfigTag* tag = iter->second;
  77
  78                         // Ensure that we have the <goodchan:name> parameter.
  79                         const std::string name = tag->getString("name");
  80                         if (name.empty())
  81                                 throw ModuleException("<goodchan:name> is a mandatory field, at " + tag->getTagLocation());
  82
  83                         goodchans.push_back(name);
  84                 }
  85
  86                 BadChannels badchans;
  87                 tags = ServerInstance->Config->ConfTags("badchan");
  88                 for (ConfigIter i = tags.first; i != tags.second; ++i)
  89                 {
  90                         ConfigTag* tag = i->second;
  91
  92                         // Ensure that we have the <badchan:name> parameter.
  93                         const std::string name = tag->getString("name");
  94                         if (name.empty())
  95                                 throw ModuleException("<badchan:name> is a mandatory field, at " + tag->getTagLocation());
  96
  97                         // Ensure that we have the <badchan:reason> parameter.
  98                         const std::string reason = tag->getString("reason");
  99                         if (reason.empty())
 100                                 throw ModuleException("<badchan:reason> is a mandatory field, at " + tag->getTagLocation());
 101
 102                         const std::string redirect = tag->getString("redirect");
 103                         if (!redirect.empty())
 104                         {
 105                                 // Ensure that <badchan:redirect> contains a channel name.
 106                                 if (!ServerInstance->IsChannel(redirect))
 107                                         throw ModuleException("<badchan:redirect> is not a valid channel name, at " + tag->getTagLocation());
 108
 109                                 // We defer the rest of the validation of the redirect channel until we have
 110                                 // finished parsing all of the badchans.
 111                         }
 112
 113                         badchans.push_back(BadChannel(name, redirect, reason, tag->getBool("allowopers")));
 114                 }
 115
 116                 // Now we have all of the badchan information recorded we can check that all redirect
 117                 // channels can actually be redirected to.
 118                 for (BadChannels::const_iterator i = badchans.begin(); i != badchans.end(); ++i)
 119                 {
 120                         const BadChannel& badchan = *i;
 121
 122                         // If there is no redirect channel we have nothing to do.
 123                         if (badchan.redirect.empty())
 124                                 continue;
 125
 126                         // If the redirect channel is whitelisted then it is okay.
 127                         bool whitelisted = false;
 128                         for (GoodChannels::const_iterator j = goodchans.begin(); j != goodchans.end(); ++j)
 129                         {
 130                                 if (InspIRCd::Match(badchan.redirect, *j))
 131                                 {
 132                                         whitelisted = true;
 133                                         break;
 134                                 }
 135                         }
 136
 137                         if (whitelisted)
 138                                 continue;
 139
 140                         // If the redirect channel is not blacklisted then it is okay.
 141                         for (BadChannels::const_iterator j = badchans.begin(); j != badchans.end(); ++j)
 142                                 if (InspIRCd::Match(badchan.redirect, j->name))
 143                                         throw ModuleException("<badchan:redirect> cannot be a blacklisted channel name");
 144                 }
 145
 146                 // The config file contained no errors so we can apply the new configuration.
 147                 badchannels.swap(badchans);
 148                 goodchannels.swap(goodchans);
 149         }
 150
 151         Version GetVersion() CXX11_OVERRIDE
 152         {
 153                 return Version("Allows the server administrator to prevent users from joining channels matching a glob.", VF_VENDOR);
 154         }
 155
 156
 157         ModResult OnUserPreJoin(LocalUser* user, Channel* chan, const std::string& cname, std::string& privs, const std::string& keygiven) CXX11_OVERRIDE
 158         {
 159                 for (BadChannels::const_iterator j = badchannels.begin(); j != badchannels.end(); ++j)
 160                 {
 161                         const BadChannel& badchan = *j;
 162
 163                         // If the channel does not match the current entry we have nothing else to do.
 164                         if (!InspIRCd::Match(cname, badchan.name))
 165                                 continue;
 166
 167                         // If the user is an oper and opers are allowed to enter this blacklisted channel
 168                         // then allow the join.
 169                         if (user->IsOper() && badchan.allowopers)
 170                                 return MOD_RES_PASSTHRU;
 171
 172                         // If the channel matches a whitelist then allow the join.
 173                         for (GoodChannels::const_iterator i = goodchannels.begin(); i != goodchannels.end(); ++i)
 174                                 if (InspIRCd::Match(cname, *i))
 175                                         return MOD_RES_PASSTHRU;
 176
 177                         // If there is no redirect chan, the user has enabled the antiredirect mode, or
 178                         // the target channel redirects elsewhere we just tell the user and deny the join.
 179                         Channel* target = NULL;
 180                         if (badchan.redirect.empty() || user->IsModeSet(antiredirectmode)
 181                                 || ((target = ServerInstance->FindChan(badchan.redirect)) && target->IsModeSet(redirectmode)))
 182                         {
 183                                 user->WriteNumeric(ERR_BADCHANNEL, cname, InspIRCd::Format("Channel %s is forbidden: %s",
 184                                         cname.c_str(), badchan.reason.c_str()));
 185                                 return MOD_RES_DENY;
 186                         }
 187
 188                         // Redirect the user to the target channel.
 189                         user->WriteNumeric(ERR_BADCHANNEL, cname, InspIRCd::Format("Channel %s is forbidden, redirecting to %s: %s",
 190                                 cname.c_str(), badchan.redirect.c_str(), badchan.reason.c_str()));
 191                         Channel::JoinUser(user, badchan.redirect);
 192                         return MOD_RES_DENY;
 193                 }
 194                 return MOD_RES_PASSTHRU;
 195         }
 196 };
 197
 198 MODULE_INIT(ModuleDenyChannels)