src/modules/m_banredirect.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  *   Copyright (C) 2008 Pippijn van Steenhoven <pip88nl@gmail.com>
   7  *   Copyright (C) 2007 Dennis Friis <peavey@inspircd.org>
   8  *   Copyright (C) 2007 Craig Edwards <craigedwards@brainbox.cc>
   9  *   Copyright (C) 2007 Oliver Lupton <oliverlupton@gmail.com>
  10  *
  11  * This file is part of InspIRCd.  InspIRCd is free software: you can
  12  * redistribute it and/or modify it under the terms of the GNU General Public
  13  * License as published by the Free Software Foundation, version 2.
  14  *
  15  * This program is distributed in the hope that it will be useful, but WITHOUT
  16  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
  17  * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
  18  * details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  22  */
  23
  24
  25 #include "inspircd.h"
  26 #include "listmode.h"
  27
  28 /* Originally written by Om, January 2009
  29  */
  30
  31 class BanRedirectEntry
  32 {
  33  public:
  34         std::string targetchan;
  35         std::string banmask;
  36
  37         BanRedirectEntry(const std::string &target = "", const std::string &mask = "")
  38         : targetchan(target), banmask(mask)
  39         {
  40         }
  41 };
  42
  43 typedef std::vector<BanRedirectEntry> BanRedirectList;
  44
  45 class BanRedirect : public ModeWatcher
  46 {
  47         ChanModeReference ban;
  48  public:
  49         SimpleExtItem<BanRedirectList> extItem;
  50         BanRedirect(Module* parent)
  51                 : ModeWatcher(parent, "ban", MODETYPE_CHANNEL)
  52                 , ban(parent, "ban")
  53                 , extItem("banredirect", ExtensionItem::EXT_CHANNEL, parent)
  54         {
  55         }
  56
  57         bool BeforeMode(User* source, User* dest, Channel* channel, std::string &param, bool adding)
  58         {
  59                 /* nick!ident@host -> nick!ident@host
  60                  * nick!ident@host#chan -> nick!ident@host#chan
  61                  * nick@host#chan -> nick!*@host#chan
  62                  * nick!ident#chan -> nick!ident@*#chan
  63                  * nick#chan -> nick!*@*#chan
  64                  */
  65
  66                 if ((channel) && !param.empty())
  67                 {
  68                         BanRedirectList* redirects;
  69
  70                         std::string mask[4];
  71                         enum { NICK, IDENT, HOST, CHAN } current = NICK;
  72                         std::string::iterator start_pos = param.begin();
  73
  74                         if (param.length() >= 2 && param[1] == ':')
  75                                 return true;
  76
  77                         if (param.find('#') == std::string::npos)
  78                                 return true;
  79
  80                         ListModeBase* banlm = static_cast<ListModeBase*>(*ban);
  81                         unsigned int maxbans = banlm->GetLimit(channel);
  82                         ListModeBase::ModeList* list = banlm->GetList(channel);
  83                         if ((list) && (adding) && (maxbans <= list->size()))
  84                         {
  85                                 source->WriteNumeric(ERR_BANLISTFULL, channel->name, InspIRCd::Format("Channel ban list for %s is full (maximum entries for this channel is %u)", channel->name.c_str(), maxbans));
  86                                 return false;
  87                         }
  88
  89                         for(std::string::iterator curr = start_pos; curr != param.end(); curr++)
  90                         {
  91                                 switch(*curr)
  92                                 {
  93                                         case '!':
  94                                                 if (current != NICK)
  95                                                         break;
  96                                                 mask[current].assign(start_pos, curr);
  97                                                 current = IDENT;
  98                                                 start_pos = curr+1;
  99                                                 break;
 100                                         case '@':
 101                                                 if (current != IDENT)
 102                                                         break;
 103                                                 mask[current].assign(start_pos, curr);
 104                                                 current = HOST;
 105                                                 start_pos = curr+1;
 106                                                 break;
 107                                         case '#':
 108                                                 if (current == CHAN)
 109                                                         break;
 110                                                 mask[current].assign(start_pos, curr);
 111                                                 current = CHAN;
 112                                                 start_pos = curr;
 113                                                 break;
 114                                 }
 115                         }
 116
 117                         if(mask[current].empty())
 118                         {
 119                                 mask[current].assign(start_pos, param.end());
 120                         }
 121
 122                         /* nick@host wants to be changed to *!nick@host rather than nick!*@host... */
 123                         if(mask[NICK].length() && mask[HOST].length() && mask[IDENT].empty())
 124                         {
 125                                 /* std::string::swap() is fast - it runs in constant time */
 126                                 mask[NICK].swap(mask[IDENT]);
 127                         }
 128
 129                         if (!mask[NICK].empty() && mask[IDENT].empty() && mask[HOST].empty())
 130                         {
 131                                 if (mask[NICK].find('.') != std::string::npos || mask[NICK].find(':') != std::string::npos)
 132                                 {
 133                                         mask[NICK].swap(mask[HOST]);
 134                                 }
 135                         }
 136
 137                         for(int i = 0; i < 3; i++)
 138                         {
 139                                 if(mask[i].empty())
 140                                 {
 141                                         mask[i].assign("*");
 142                                 }
 143                         }
 144
 145                         param.assign(mask[NICK]).append(1, '!').append(mask[IDENT]).append(1, '@').append(mask[HOST]);
 146
 147                         if(mask[CHAN].length())
 148                         {
 149                                 if (adding && IS_LOCAL(source))
 150                                 {
 151                                         if (!ServerInstance->IsChannel(mask[CHAN]))
 152                                         {
 153                                                 source->WriteNumeric(ERR_NOSUCHCHANNEL, channel->name, InspIRCd::Format("Invalid channel name in redirection (%s)", mask[CHAN].c_str()));
 154                                                 return false;
 155                                         }
 156
 157                                         Channel *c = ServerInstance->FindChan(mask[CHAN]);
 158                                         if (!c)
 159                                         {
 160                                                 source->WriteNumeric(690, InspIRCd::Format("Target channel %s must exist to be set as a redirect.", mask[CHAN].c_str()));
 161                                                 return false;
 162                                         }
 163                                         else if (adding && c->GetPrefixValue(source) < OP_VALUE)
 164                                         {
 165                                                 source->WriteNumeric(690, InspIRCd::Format("You must be opped on %s to set it as a redirect.", mask[CHAN].c_str()));
 166                                                 return false;
 167                                         }
 168
 169                                         if (assign(channel->name) == mask[CHAN])
 170                                         {
 171                                                 source->WriteNumeric(690, channel->name, "You cannot set a ban redirection to the channel the ban is on");
 172                                                 return false;
 173                                         }
 174                                 }
 175
 176                                 if(adding)
 177                                 {
 178                                         /* It's a properly valid redirecting ban, and we're adding it */
 179                                         redirects = extItem.get(channel);
 180                                         if (!redirects)
 181                                         {
 182                                                 redirects = new BanRedirectList;
 183                                                 extItem.set(channel, redirects);
 184                                         }
 185
 186                                         /* Here 'param' doesn't have the channel on it yet */
 187                                         redirects->push_back(BanRedirectEntry(mask[CHAN], param));
 188
 189                                         /* Now it does */
 190                                         param.append(mask[CHAN]);
 191                                 }
 192                                 else
 193                                 {
 194                                         /* Removing a ban, if there's no extensible there are no redirecting bans and we're fine. */
 195                                         redirects = extItem.get(channel);
 196                                         if (redirects)
 197                                         {
 198                                                 /* But there were, so we need to remove the matching one if there is one */
 199
 200                                                 for(BanRedirectList::iterator redir = redirects->begin(); redir != redirects->end(); redir++)
 201                                                 {
 202                                                         /* Ugly as fuck */
 203                                                         if((irc::string(redir->targetchan.c_str()) == irc::string(mask[CHAN].c_str())) && (irc::string(redir->banmask.c_str()) == irc::string(param.c_str())))
 204                                                         {
 205                                                                 redirects->erase(redir);
 206
 207                                                                 if(redirects->empty())
 208                                                                 {
 209                                                                         extItem.unset(channel);
 210                                                                 }
 211
 212                                                                 break;
 213                                                         }
 214                                                 }
 215                                         }
 216
 217                                         /* Append the channel so the default +b handler can remove the entry too */
 218                                         param.append(mask[CHAN]);
 219                                 }
 220                         }
 221                 }
 222
 223                 return true;
 224         }
 225 };
 226
 227 class ModuleBanRedirect : public Module
 228 {
 229         BanRedirect re;
 230         bool nofollow;
 231         ChanModeReference limitmode;
 232         ChanModeReference redirectmode;
 233
 234  public:
 235         ModuleBanRedirect()
 236                 : re(this)
 237                 , nofollow(false)
 238                 , limitmode(this, "limit")
 239                 , redirectmode(this, "redirect")
 240         {
 241         }
 242
 243         void OnCleanup(int target_type, void* item) CXX11_OVERRIDE
 244         {
 245                 if(target_type == TYPE_CHANNEL)
 246                 {
 247                         Channel* chan = static_cast<Channel*>(item);
 248                         BanRedirectList* redirects = re.extItem.get(chan);
 249
 250                         if(redirects)
 251                         {
 252                                 ModeHandler* ban = ServerInstance->Modes->FindMode('b', MODETYPE_CHANNEL);
 253                                 Modes::ChangeList changelist;
 254
 255                                 for(BanRedirectList::iterator i = redirects->begin(); i != redirects->end(); i++)
 256                                         changelist.push_remove(ban, i->targetchan.insert(0, i->banmask));
 257
 258                                 for(BanRedirectList::iterator i = redirects->begin(); i != redirects->end(); i++)
 259                                         changelist.push_add(ban, i->banmask);
 260
 261                                 ServerInstance->Modes->Process(ServerInstance->FakeClient, chan, NULL, changelist, ModeParser::MODE_LOCALONLY);
 262                         }
 263                 }
 264         }
 265
 266         ModResult OnUserPreJoin(LocalUser* user, Channel* chan, const std::string& cname, std::string& privs, const std::string& keygiven) CXX11_OVERRIDE
 267         {
 268                 if (chan)
 269                 {
 270                         BanRedirectList* redirects = re.extItem.get(chan);
 271
 272                         if (redirects)
 273                         {
 274                                 /* We actually had some ban redirects to check */
 275
 276                                 /* This was replaced with user->MakeHostIP() when I had a snprintf(), but MakeHostIP() doesn't seem to add the nick.
 277                                  * Maybe we should have a GetFullIPHost() or something to match GetFullHost() and GetFullRealHost?
 278                                  */
 279
 280                                 ModResult result;
 281                                 FIRST_MOD_RESULT(OnCheckChannelBan, result, (user, chan));
 282                                 if (result == MOD_RES_ALLOW)
 283                                 {
 284                                         // they have a ban exception
 285                                         return MOD_RES_PASSTHRU;
 286                                 }
 287
 288                                 std::string ipmask(user->nick);
 289                                 ipmask.append(1, '!').append(user->MakeHostIP());
 290
 291                                 for(BanRedirectList::iterator redir = redirects->begin(); redir != redirects->end(); redir++)
 292                                 {
 293                                         if(InspIRCd::Match(user->GetFullRealHost(), redir->banmask) || InspIRCd::Match(user->GetFullHost(), redir->banmask) || InspIRCd::MatchCIDR(ipmask, redir->banmask))
 294                                         {
 295                                                 /* This prevents recursion when a user sets multiple ban redirects in a chain
 296                                                  * (thanks Potter)
 297                                                  *
 298                                                  * If we're here and nofollow is true then we're already redirecting this user
 299                                                  * and there's a redirecting ban set on this channel that matches him, too.
 300                                                  * Deny both joins.
 301                                                  */
 302                                                 if (nofollow)
 303                                                         return MOD_RES_DENY;
 304
 305                                                 /* tell them they're banned and are being transferred */
 306                                                 Channel* destchan = ServerInstance->FindChan(redir->targetchan);
 307                                                 std::string destlimit;
 308
 309                                                 if (destchan)
 310                                                         destlimit = destchan->GetModeParameter(limitmode);
 311
 312                                                 if(destchan && destchan->IsModeSet(redirectmode) && !destlimit.empty() && (destchan->GetUserCounter() >= atoi(destlimit.c_str())))
 313                                                 {
 314                                                         user->WriteNumeric(ERR_BANNEDFROMCHAN, chan->name, "Cannot join channel (You are banned)");
 315                                                         return MOD_RES_DENY;
 316                                                 }
 317                                                 else
 318                                                 {
 319                                                         user->WriteNumeric(ERR_BANNEDFROMCHAN, chan->name, "Cannot join channel (You are banned)");
 320                                                         user->WriteNumeric(470, chan->name, redir->targetchan, "You are banned from this channel, so you are automatically transferred to the redirected channel.");
 321                                                         nofollow = true;
 322                                                         Channel::JoinUser(user, redir->targetchan);
 323                                                         nofollow = false;
 324                                                         return MOD_RES_DENY;
 325                                                 }
 326                                         }
 327                                 }
 328                         }
 329                 }
 330                 return MOD_RES_PASSTHRU;
 331         }
 332
 333         Version GetVersion() CXX11_OVERRIDE
 334         {
 335                 return Version("Allows an extended ban (+b) syntax redirecting banned users to another channel", VF_COMMON|VF_VENDOR);
 336         }
 337 };
 338
 339 MODULE_INIT(ModuleBanRedirect)