src/modules/m_banredirect.cpp

   1 /*       +------------------------------------+
   2  *       | Inspire Internet Relay Chat Daemon |
   3  *       +------------------------------------+
   4  *
   5  *  InspIRCd: (C) 2002-2009 InspIRCd Development Team
   6  * See: http://wiki.inspircd.org/Credits
   7  *
   8  * This program is free but copyrighted software; see
   9  *            the file COPYING for details.
  10  *
  11  * ---------------------------------------------------
  12  */
  13
  14 #include "inspircd.h"
  15 #include "u_listmode.h"
  16
  17 /* $ModDesc: Allows an extended ban (+b) syntax redirecting banned users to another channel */
  18 /* $ModDep: ../../include/u_listmode.h */
  19
  20 /* Originally written by Om, January 2009
  21  */
  22
  23 class BanRedirectEntry
  24 {
  25  public:
  26         std::string targetchan;
  27         std::string banmask;
  28
  29         BanRedirectEntry(const std::string &target = "", const std::string &mask = "")
  30         : targetchan(target), banmask(mask)
  31         {
  32         }
  33 };
  34
  35 typedef std::vector<BanRedirectEntry> BanRedirectList;
  36 typedef std::deque<std::string> StringDeque;
  37
  38 class BanRedirect : public ModeWatcher
  39 {
  40  public:
  41         SimpleExtItem<BanRedirectList> extItem;
  42         BanRedirect(Module* parent) : ModeWatcher(parent, 'b', MODETYPE_CHANNEL),
  43                 extItem("banredirect", parent)
  44         {
  45         }
  46
  47         bool BeforeMode(User* source, User* dest, Channel* channel, std::string &param, bool adding, ModeType type)
  48         {
  49                 /* nick!ident@host -> nick!ident@host
  50                  * nick!ident@host#chan -> nick!ident@host#chan
  51                  * nick@host#chan -> nick!*@host#chan
  52                  * nick!ident#chan -> nick!ident@*#chan
  53                  * nick#chan -> nick!*@*#chan
  54                  */
  55
  56                 if(channel && (type == MODETYPE_CHANNEL) && param.length())
  57                 {
  58                         BanRedirectList* redirects;
  59
  60                         std::string mask[4];
  61                         enum { NICK, IDENT, HOST, CHAN } current = NICK;
  62                         std::string::iterator start_pos = param.begin();
  63                         long maxbans = channel->GetMaxBans();
  64
  65                         if (param.length() >= 2 && param[1] == ':')
  66                                 return true;
  67
  68                         if(adding && (channel->bans.size() > static_cast<unsigned>(maxbans)))
  69                         {
  70                                 source->WriteNumeric(478, "%s %s :Channel ban list for %s is full (maximum entries for this channel is %ld)", source->nick.c_str(), channel->name.c_str(), channel->name.c_str(), maxbans);
  71                                 return false;
  72                         }
  73
  74                         for(std::string::iterator curr = start_pos; curr != param.end(); curr++)
  75                         {
  76                                 switch(*curr)
  77                                 {
  78                                         case '!':
  79                                                 mask[current].assign(start_pos, curr);
  80                                                 current = IDENT;
  81                                                 start_pos = curr+1;
  82                                                 break;
  83                                         case '@':
  84                                                 mask[current].assign(start_pos, curr);
  85                                                 current = HOST;
  86                                                 start_pos = curr+1;
  87                                                 break;
  88                                         case '#':
  89                                                 /* bug #921: don't barf when redirecting to ## channels */
  90                                                 if (current != CHAN)
  91                                                 {
  92                                                         mask[current].assign(start_pos, curr);
  93                                                         current = CHAN;
  94                                                         start_pos = curr;
  95                                                 }
  96                                                 break;
  97                                 }
  98                         }
  99
 100                         if(mask[current].empty())
 101                         {
 102                                 mask[current].assign(start_pos, param.end());
 103                         }
 104
 105                         /* nick@host wants to be changed to *!nick@host rather than nick!*@host... */
 106                         if(mask[NICK].length() && mask[HOST].length() && mask[IDENT].empty())
 107                         {
 108                                 /* std::string::swap() is fast - it runs in constant time */
 109                                 mask[NICK].swap(mask[IDENT]);
 110                         }
 111
 112                         for(int i = 0; i < 3; i++)
 113                         {
 114                                 if(mask[i].empty())
 115                                 {
 116                                         mask[i].assign("*");
 117                                 }
 118                         }
 119
 120                         param.assign(mask[NICK]).append(1, '!').append(mask[IDENT]).append(1, '@').append(mask[HOST]);
 121
 122                         if(mask[CHAN].length())
 123                         {
 124                                 if (IS_LOCAL(source))
 125                                 {
 126                                         if (!ServerInstance->IsChannel(mask[CHAN].c_str(),  ServerInstance->Config->Limits.ChanMax))
 127                                         {
 128                                                 source->WriteNumeric(403, "%s %s :Invalid channel name in redirection (%s)", source->nick.c_str(), channel->name.c_str(), mask[CHAN].c_str());
 129                                                 return false;
 130                                         }
 131
 132                                         Channel *c = ServerInstance->FindChan(mask[CHAN].c_str());
 133                                         if (!c)
 134                                         {
 135                                                 source->WriteNumeric(690, "%s :Target channel %s must exist to be set as a redirect.",source->nick.c_str(),mask[CHAN].c_str());
 136                                                 return false;
 137                                         }
 138                                         else if (c->GetPrefixValue(source) < OP_VALUE)
 139                                         {
 140                                                 source->WriteNumeric(690, "%s :You must be opped on %s to set it as a redirect.",source->nick.c_str(), mask[CHAN].c_str());
 141                                                 return false;
 142                                         }
 143
 144                                         if (assign(channel->name) == mask[CHAN])
 145                                         {
 146                                                 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());
 147                                                 return false;
 148                                         }
 149                                 }
 150
 151                                 if(adding)
 152                                 {
 153                                         /* It's a properly valid redirecting ban, and we're adding it */
 154                                         redirects = extItem.get(channel);
 155                                         if (!redirects)
 156                                         {
 157                                                 redirects = new BanRedirectList;
 158                                                 extItem.set(channel, redirects);
 159                                         }
 160
 161                                         /* Here 'param' doesn't have the channel on it yet */
 162                                         redirects->push_back(BanRedirectEntry(mask[CHAN].c_str(), param.c_str()));
 163
 164                                         /* Now it does */
 165                                         param.append(mask[CHAN]);
 166                                 }
 167                                 else
 168                                 {
 169                                         /* Removing a ban, if there's no extensible there are no redirecting bans and we're fine. */
 170                                         redirects = extItem.get(channel);
 171                                         if (redirects)
 172                                         {
 173                                                 /* But there were, so we need to remove the matching one if there is one */
 174
 175                                                 for(BanRedirectList::iterator redir = redirects->begin(); redir != redirects->end(); redir++)
 176                                                 {
 177                                                         /* Ugly as fuck */
 178                                                         if((irc::string(redir->targetchan.c_str()) == irc::string(mask[CHAN].c_str())) && (irc::string(redir->banmask.c_str()) == irc::string(param.c_str())))
 179                                                         {
 180                                                                 redirects->erase(redir);
 181
 182                                                                 if(redirects->empty())
 183                                                                 {
 184                                                                         extItem.unset(channel);
 185                                                                 }
 186
 187                                                                 break;
 188                                                         }
 189                                                 }
 190                                         }
 191
 192                                         /* Append the channel so the default +b handler can remove the entry too */
 193                                         param.append(mask[CHAN]);
 194                                 }
 195                         }
 196                 }
 197
 198                 return true;
 199         }
 200 };
 201
 202 class ModuleBanRedirect : public Module
 203 {
 204         BanRedirect re;
 205         bool nofollow;
 206         Module* ExceptionModule;
 207
 208  public:
 209         ModuleBanRedirect()
 210         : re(this)
 211         {
 212                 nofollow = false;
 213
 214                 if(!ServerInstance->Modes->AddModeWatcher(&re))
 215                         throw ModuleException("Could not add mode watcher");
 216
 217                 OnRehash(NULL);
 218
 219                 ServerInstance->Extensions.Register(&re.extItem);
 220                 Implementation list[] = { I_OnRehash, I_OnUserPreJoin, I_OnChannelDelete };
 221                 ServerInstance->Modules->Attach(list, this, 3);
 222         }
 223
 224         virtual void OnChannelDelete(Channel* chan)
 225         {
 226                 OnCleanup(TYPE_CHANNEL, chan);
 227         }
 228
 229         virtual void OnCleanup(int target_type, void* item)
 230         {
 231                 if(target_type == TYPE_CHANNEL)
 232                 {
 233                         Channel* chan = static_cast<Channel*>(item);
 234                         BanRedirectList* redirects = re.extItem.get(chan);
 235
 236                         if(redirects)
 237                         {
 238                                 irc::modestacker modestack(false);
 239                                 StringDeque stackresult;
 240                                 std::vector<std::string> mode_junk;
 241                                 mode_junk.push_back(chan->name);
 242
 243                                 for(BanRedirectList::iterator i = redirects->begin(); i != redirects->end(); i++)
 244                                 {
 245                                         modestack.Push('b', i->targetchan.insert(0, i->banmask));
 246                                 }
 247
 248                                 for(BanRedirectList::iterator i = redirects->begin(); i != redirects->end(); i++)
 249                                 {
 250                                         modestack.PushPlus();
 251                                         modestack.Push('b', i->banmask);
 252                                 }
 253
 254                                 while(modestack.GetStackedLine(stackresult))
 255                                 {
 256                                         mode_junk.insert(mode_junk.end(), stackresult.begin(), stackresult.end());
 257                                         ServerInstance->SendMode(mode_junk, ServerInstance->FakeClient);
 258                                         mode_junk.erase(mode_junk.begin() + 1, mode_junk.end());
 259                                 }
 260                         }
 261                 }
 262         }
 263
 264         virtual void OnRehash(User* user)
 265         {
 266                 ExceptionModule = ServerInstance->Modules->Find("m_banexception.so");
 267         }
 268
 269         virtual ModResult OnUserPreJoin(User* user, Channel* chan, const char* cname, std::string &privs, const std::string &keygiven)
 270         {
 271                 /* This prevents recursion when a user sets multiple ban redirects in a chain
 272                  * (thanks Potter)
 273                  */
 274                 if (nofollow)
 275                         return MOD_RES_PASSTHRU;
 276
 277                 /* Return 1 to prevent the join, 0 to allow it */
 278                 if (chan)
 279                 {
 280                         BanRedirectList* redirects = re.extItem.get(chan);
 281
 282                         if (redirects)
 283                         {
 284                                 /* We actually had some ban redirects to check */
 285
 286                                 /* This was replaced with user->MakeHostIP() when I had a snprintf(), but MakeHostIP() doesn't seem to add the nick.
 287                                  * Maybe we should have a GetFullIPHost() or something to match GetFullHost() and GetFullRealHost?
 288                                  */
 289
 290                                 ModResult result;
 291                                 FIRST_MOD_RESULT(OnCheckChannelBan, result, (user, chan));
 292                                 if (result == MOD_RES_ALLOW)
 293                                 {
 294                                         // they have a ban exception
 295                                         return MOD_RES_PASSTHRU;
 296                                 }
 297
 298                                 std::string ipmask(user->nick);
 299                                 ipmask.append(1, '!').append(user->MakeHostIP());
 300
 301                                 for(BanRedirectList::iterator redir = redirects->begin(); redir != redirects->end(); redir++)
 302                                 {
 303                                         if(InspIRCd::Match(user->GetFullRealHost(), redir->banmask) || InspIRCd::Match(user->GetFullHost(), redir->banmask) || InspIRCd::MatchCIDR(ipmask, redir->banmask))
 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('l');
 311
 312                                                 if(destchan && ServerInstance->Modules->Find("m_redirect.so") && destchan->IsModeSet('L') && !destlimit.empty() && (destchan->GetUserCounter() >= atoi(destlimit.c_str())))
 313                                                 {
 314                                                         user->WriteNumeric(474, "%s %s :Cannot join channel (You are banned)", user->nick.c_str(), chan->name.c_str());
 315                                                         return MOD_RES_DENY;
 316                                                 }
 317                                                 else
 318                                                 {
 319                                                         user->WriteNumeric(474, "%s %s :Cannot join channel (You are banned)", user->nick.c_str(), chan->name.c_str());
 320                                                         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());
 321                                                         nofollow = true;
 322                                                         Channel::JoinUser(user, redir->targetchan.c_str(), false, "", false, ServerInstance->Time());
 323                                                         nofollow = false;
 324                                                         return MOD_RES_DENY;
 325                                                 }
 326                                         }
 327                                 }
 328                         }
 329                 }
 330                 return MOD_RES_PASSTHRU;
 331         }
 332
 333         virtual ~ModuleBanRedirect()
 334         {
 335         }
 336
 337         virtual Version GetVersion()
 338         {
 339                 return Version("Allows an extended ban (+b) syntax redirecting banned users to another channel", VF_COMMON|VF_VENDOR);
 340         }
 341
 342         void Prioritize()
 343         {
 344                 Module* banex = ServerInstance->Modules->Find("m_banexception.so");
 345                 ServerInstance->Modules->SetPriority(this, I_OnUserPreJoin, PRIORITY_BEFORE, &banex);
 346         }
 347 };
 348
 349 MODULE_INIT(ModuleBanRedirect)