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 /* $ModDesc: Allows an extended ban (+b) syntax redirecting banned users to another channel */
  29
  30 /* Originally written by Om, January 2009
  31  */
  32
  33 class BanRedirectEntry
  34 {
  35  public:
  36         std::string targetchan;
  37         std::string banmask;
  38
  39         BanRedirectEntry(const std::string &target = "", const std::string &mask = "")
  40         : targetchan(target), banmask(mask)
  41         {
  42         }
  43 };
  44
  45 typedef std::vector<BanRedirectEntry> BanRedirectList;
  46
  47 class BanRedirect : public ModeWatcher
  48 {
  49         ModeReference ban;
  50  public:
  51         SimpleExtItem<BanRedirectList> extItem;
  52         BanRedirect(Module* parent)
  53                 : ModeWatcher(parent, "ban", MODETYPE_CHANNEL)
  54                 , ban(parent, "ban")
  55                 , extItem("banredirect", parent)
  56         {
  57         }
  58
  59         bool BeforeMode(User* source, User* dest, Channel* channel, std::string &param, bool adding)
  60         {
  61                 /* nick!ident@host -> nick!ident@host
  62                  * nick!ident@host#chan -> nick!ident@host#chan
  63                  * nick@host#chan -> nick!*@host#chan
  64                  * nick!ident#chan -> nick!ident@*#chan
  65                  * nick#chan -> nick!*@*#chan
  66                  */
  67
  68                 if ((channel) && !param.empty())
  69                 {
  70                         BanRedirectList* redirects;
  71
  72                         std::string mask[4];
  73                         enum { NICK, IDENT, HOST, CHAN } current = NICK;
  74                         std::string::iterator start_pos = param.begin();
  75
  76                         if (param.length() >= 2 && param[1] == ':')
  77                                 return true;
  78
  79                         ListModeBase* banlm = static_cast<ListModeBase*>(*ban);
  80                         unsigned int maxbans = banlm->GetLimit(channel);
  81                         ListModeBase::ModeList* list = banlm->GetList(channel);
  82                         if ((list) && (adding) && (maxbans <= list->size()))
  83                         {
  84                                 source->WriteNumeric(478, "%s %s :Channel ban list for %s is full (maximum entries for this channel is %u)", source->nick.c_str(), channel->name.c_str(), channel->name.c_str(), maxbans);
  85                                 return false;
  86                         }
  87
  88                         for(std::string::iterator curr = start_pos; curr != param.end(); curr++)
  89                         {
  90                                 switch(*curr)
  91                                 {
  92                                         case '!':
  93                                                 if (current != NICK)
  94                                                         break;
  95                                                 mask[current].assign(start_pos, curr);
  96                                                 current = IDENT;
  97                                                 start_pos = curr+1;
  98                                                 break;
  99                                         case '@':
 100                                                 if (current != IDENT)
 101                                                         break;
 102                                                 mask[current].assign(start_pos, curr);
 103                                                 current = HOST;
 104                                                 start_pos = curr+1;
 105                                                 break;
 106                                         case '#':
 107                                                 if (current == CHAN)
 108                                                         break;
 109                                                 mask[current].assign(start_pos, curr);
 110                                                 current = CHAN;
 111                                                 start_pos = curr;
 112                                                 break;
 113                                 }
 114                         }
 115
 116                         if(mask[current].empty())
 117                         {
 118                                 mask[current].assign(start_pos, param.end());
 119                         }
 120
 121                         /* nick@host wants to be changed to *!nick@host rather than nick!*@host... */
 122                         if(mask[NICK].length() && mask[HOST].length() && mask[IDENT].empty())
 123                         {
 124                                 /* std::string::swap() is fast - it runs in constant time */
 125                                 mask[NICK].swap(mask[IDENT]);
 126                         }
 127
 128                         for(int i = 0; i < 3; i++)
 129                         {
 130                                 if(mask[i].empty())
 131                                 {
 132                                         mask[i].assign("*");
 133                                 }
 134                         }
 135
 136                         param.assign(mask[NICK]).append(1, '!').append(mask[IDENT]).append(1, '@').append(mask[HOST]);
 137
 138                         if(mask[CHAN].length())
 139                         {
 140                                 if (adding && IS_LOCAL(source))
 141                                 {
 142                                         if (!ServerInstance->IsChannel(mask[CHAN]))
 143                                         {
 144                                                 source->WriteNumeric(403, "%s %s :Invalid channel name in redirection (%s)", source->nick.c_str(), channel->name.c_str(), mask[CHAN].c_str());
 145                                                 return false;
 146                                         }
 147
 148                                         Channel *c = ServerInstance->FindChan(mask[CHAN]);
 149                                         if (!c)
 150                                         {
 151                                                 source->WriteNumeric(690, "%s :Target channel %s must exist to be set as a redirect.",source->nick.c_str(),mask[CHAN].c_str());
 152                                                 return false;
 153                                         }
 154                                         else if (adding && c->GetPrefixValue(source) < OP_VALUE)
 155                                         {
 156                                                 source->WriteNumeric(690, "%s :You must be opped on %s to set it as a redirect.",source->nick.c_str(), mask[CHAN].c_str());
 157                                                 return false;
 158                                         }
 159
 160                                         if (assign(channel->name) == mask[CHAN])
 161                                         {
 162                                                 source->WriteNumeric(690, "%s %s :You cannot set a ban redirection to the channel the ban is on", source->nick.c_str(), channel->name.c_str());
 163                                                 return false;
 164                                         }
 165                                 }
 166
 167                                 if(adding)
 168                                 {
 169                                         /* It's a properly valid redirecting ban, and we're adding it */
 170                                         redirects = extItem.get(channel);
 171                                         if (!redirects)
 172                                         {
 173                                                 redirects = new BanRedirectList;
 174                                                 extItem.set(channel, redirects);
 175                                         }
 176
 177                                         /* Here 'param' doesn't have the channel on it yet */
 178                                         redirects->push_back(BanRedirectEntry(mask[CHAN], param));
 179
 180                                         /* Now it does */
 181                                         param.append(mask[CHAN]);
 182                                 }
 183                                 else
 184                                 {
 185                                         /* Removing a ban, if there's no extensible there are no redirecting bans and we're fine. */
 186                                         redirects = extItem.get(channel);
 187                                         if (redirects)
 188                                         {
 189                                                 /* But there were, so we need to remove the matching one if there is one */
 190
 191                                                 for(BanRedirectList::iterator redir = redirects->begin(); redir != redirects->end(); redir++)
 192                                                 {
 193                                                         /* Ugly as fuck */
 194                                                         if((irc::string(redir->targetchan.c_str()) == irc::string(mask[CHAN].c_str())) && (irc::string(redir->banmask.c_str()) == irc::string(param.c_str())))
 195                                                         {
 196                                                                 redirects->erase(redir);
 197
 198                                                                 if(redirects->empty())
 199                                                                 {
 200                                                                         extItem.unset(channel);
 201                                                                 }
 202
 203                                                                 break;
 204                                                         }
 205                                                 }
 206                                         }
 207
 208                                         /* Append the channel so the default +b handler can remove the entry too */
 209                                         param.append(mask[CHAN]);
 210                                 }
 211                         }
 212                 }
 213
 214                 return true;
 215         }
 216 };
 217
 218 class ModuleBanRedirect : public Module
 219 {
 220         BanRedirect re;
 221         bool nofollow;
 222
 223  public:
 224         ModuleBanRedirect()
 225         : re(this)
 226         {
 227                 nofollow = false;
 228         }
 229
 230
 231         void init() CXX11_OVERRIDE
 232         {
 233                 ServerInstance->Modes->AddModeWatcher(&re);
 234                 ServerInstance->Modules->AddService(re.extItem);
 235                 Implementation list[] = { I_OnUserPreJoin };
 236                 ServerInstance->Modules->Attach(list, this, sizeof(list)/sizeof(Implementation));
 237         }
 238
 239         void OnCleanup(int target_type, void* item) CXX11_OVERRIDE
 240         {
 241                 if(target_type == TYPE_CHANNEL)
 242                 {
 243                         Channel* chan = static_cast<Channel*>(item);
 244                         BanRedirectList* redirects = re.extItem.get(chan);
 245
 246                         if(redirects)
 247                         {
 248                                 irc::modestacker modestack(false);
 249
 250                                 for(BanRedirectList::iterator i = redirects->begin(); i != redirects->end(); i++)
 251                                 {
 252                                         modestack.Push('b', i->targetchan.insert(0, i->banmask));
 253                                 }
 254
 255                                 for(BanRedirectList::iterator i = redirects->begin(); i != redirects->end(); i++)
 256                                 {
 257                                         modestack.PushPlus();
 258                                         modestack.Push('b', i->banmask);
 259                                 }
 260
 261                                 std::vector<std::string> stackresult;
 262                                 stackresult.push_back(chan->name);
 263                                 while (modestack.GetStackedLine(stackresult))
 264                                 {
 265                                         ServerInstance->Modes->Process(stackresult, ServerInstance->FakeClient, ModeParser::MODE_LOCALONLY);
 266                                         stackresult.erase(stackresult.begin() + 1, stackresult.end());
 267                                 }
 268                         }
 269                 }
 270         }
 271
 272         ModResult OnUserPreJoin(LocalUser* user, Channel* chan, const std::string& cname, std::string& privs, const std::string& keygiven) CXX11_OVERRIDE
 273         {
 274                 if (chan)
 275                 {
 276                         BanRedirectList* redirects = re.extItem.get(chan);
 277
 278                         if (redirects)
 279                         {
 280                                 /* We actually had some ban redirects to check */
 281
 282                                 /* This was replaced with user->MakeHostIP() when I had a snprintf(), but MakeHostIP() doesn't seem to add the nick.
 283                                  * Maybe we should have a GetFullIPHost() or something to match GetFullHost() and GetFullRealHost?
 284                                  */
 285
 286                                 ModResult result;
 287                                 FIRST_MOD_RESULT(OnCheckChannelBan, result, (user, chan));
 288                                 if (result == MOD_RES_ALLOW)
 289                                 {
 290                                         // they have a ban exception
 291                                         return MOD_RES_PASSTHRU;
 292                                 }
 293
 294                                 std::string ipmask(user->nick);
 295                                 ipmask.append(1, '!').append(user->MakeHostIP());
 296
 297                                 for(BanRedirectList::iterator redir = redirects->begin(); redir != redirects->end(); redir++)
 298                                 {
 299                                         if(InspIRCd::Match(user->GetFullRealHost(), redir->banmask) || InspIRCd::Match(user->GetFullHost(), redir->banmask) || InspIRCd::MatchCIDR(ipmask, redir->banmask))
 300                                         {
 301                                                 /* This prevents recursion when a user sets multiple ban redirects in a chain
 302                                                  * (thanks Potter)
 303                                                  *
 304                                                  * If we're here and nofollow is true then we're already redirecting this user
 305                                                  * and there's a redirecting ban set on this channel that matches him, too.
 306                                                  * Deny both joins.
 307                                                  */
 308                                                 if (nofollow)
 309                                                         return MOD_RES_DENY;
 310
 311                                                 /* tell them they're banned and are being transferred */
 312                                                 Channel* destchan = ServerInstance->FindChan(redir->targetchan);
 313                                                 std::string destlimit;
 314
 315                                                 if (destchan)
 316                                                         destlimit = destchan->GetModeParameter('l');
 317
 318                                                 if(destchan && ServerInstance->Modules->Find("m_redirect.so") && destchan->IsModeSet('L') && !destlimit.empty() && (destchan->GetUserCounter() >= atoi(destlimit.c_str())))
 319                                                 {
 320                                                         user->WriteNumeric(474, "%s %s :Cannot join channel (You are banned)", user->nick.c_str(), chan->name.c_str());
 321                                                         return MOD_RES_DENY;
 322                                                 }
 323                                                 else
 324                                                 {
 325                                                         user->WriteNumeric(474, "%s %s :Cannot join channel (You are banned)", user->nick.c_str(), chan->name.c_str());
 326                                                         user->WriteNumeric(470, "%s %s %s :You are banned from this channel, so you are automatically transfered to the redirected channel.", user->nick.c_str(), chan->name.c_str(), redir->targetchan.c_str());
 327                                                         nofollow = true;
 328                                                         Channel::JoinUser(user, redir->targetchan);
 329                                                         nofollow = false;
 330                                                         return MOD_RES_DENY;
 331                                                 }
 332                                         }
 333                                 }
 334                         }
 335                 }
 336                 return MOD_RES_PASSTHRU;
 337         }
 338
 339         ~ModuleBanRedirect()
 340         {
 341                 /* XXX is this the best place to do this? */
 342                 if (!ServerInstance->Modes->DelModeWatcher(&re))
 343                         ServerInstance->Logs->Log("m_banredirect.so", LOG_DEBUG, "Failed to delete modewatcher!");
 344         }
 345
 346         Version GetVersion() CXX11_OVERRIDE
 347         {
 348                 return Version("Allows an extended ban (+b) syntax redirecting banned users to another channel", VF_COMMON|VF_VENDOR);
 349         }
 350 };
 351
 352 MODULE_INIT(ModuleBanRedirect)