src/modules/m_banredirect.cpp

   1 /*       +------------------------------------+
   2  *       | Inspire Internet Relay Chat Daemon |
   3  *       +------------------------------------+
   4  *
   5  *  InspIRCd: (C) 2002-2008 InspIRCd Development Team
   6  * See: http://www.inspircd.org/wiki/index.php/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 2008
  21  */
  22
  23 class BanRedirectEntry : public classbase
  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  private:
  41         InspIRCd* Srv;
  42  public:
  43         BanRedirect(InspIRCd* Instance)
  44         : ModeWatcher(Instance, 'b', MODETYPE_CHANNEL), Srv(Instance)
  45         {
  46         }
  47
  48         bool BeforeMode(User* source, User* dest, Channel* channel, std::string &param, bool adding, ModeType type, bool)
  49         {
  50                 /* nick!ident@host -> nick!ident@host
  51                  * nick!ident@host#chan -> nick!ident@host#chan
  52                  * nick@host#chan -> nick!*@host#chan
  53                  * nick!ident#chan -> nick!ident@*#chan
  54                  * nick#chan -> nick!*@*#chan
  55                  */
  56
  57                 if(channel && (type == MODETYPE_CHANNEL) && param.length())
  58                 {
  59                         BanRedirectList* redirects;
  60
  61                         std::string mask[4];
  62                         enum { NICK, IDENT, HOST, CHAN } current = NICK;
  63                         std::string::iterator start_pos = param.begin();
  64                         long maxbans = channel->GetMaxBans();
  65
  66                         if (param.length() >= 2 && param[1] == ':')
  67                                 return true;
  68
  69                         if(adding && (channel->bans.size() > static_cast<unsigned>(maxbans)))
  70                         {
  71                                 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);
  72                                 return false;
  73                         }
  74
  75                         for(std::string::iterator curr = start_pos; curr != param.end(); curr++)
  76                         {
  77                                 switch(*curr)
  78                                 {
  79                                         case '!':
  80                                                 mask[current].assign(start_pos, curr);
  81                                                 current = IDENT;
  82                                                 start_pos = curr+1;
  83                                                 break;
  84                                         case '@':
  85                                                 mask[current].assign(start_pos, curr);
  86                                                 current = HOST;
  87                                                 start_pos = curr+1;
  88                                                 break;
  89                                         case '#':
  90                                                 mask[current].assign(start_pos, curr);
  91                                                 current = CHAN;
  92                                                 start_pos = curr;
  93                                                 break;
  94                                 }
  95                         }
  96
  97                         if(mask[current].empty())
  98                         {
  99                                 mask[current].assign(start_pos, param.end());
 100                         }
 101
 102                         /* nick@host wants to be changed to *!nick@host rather than nick!*@host... */
 103                         if(mask[NICK].length() && mask[HOST].length() && mask[IDENT].empty())
 104                         {
 105                                 /* std::string::swap() is fast - it runs in constant time */
 106                                 mask[NICK].swap(mask[IDENT]);
 107                         }
 108
 109                         for(int i = 0; i < 3; i++)
 110                         {
 111                                 if(mask[i].empty())
 112                                 {
 113                                         mask[i].assign("*");
 114                                 }
 115                         }
 116
 117                         param.assign(mask[NICK]).append(1, '!').append(mask[IDENT]).append(1, '@').append(mask[HOST]);
 118
 119                         if(mask[CHAN].length())
 120                         {
 121                                 if(!IS_LOCAL(source) || Srv->IsChannel(mask[CHAN].c_str(), ServerInstance->Config->Limits.ChanMax))
 122                                 {
 123                                         if (assign(channel->name) == mask[CHAN])
 124                                         {
 125                                                 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());
 126                                                 return false;
 127                                         }
 128                                         else
 129                                         {
 130                                                 if(adding)
 131                                                 {
 132                                                         /* It's a properly valid redirecting ban, and we're adding it */
 133                                                         if(!channel->GetExt("banredirects", redirects))
 134                                                         {
 135                                                                 redirects = new BanRedirectList;
 136                                                                 channel->Extend("banredirects", redirects);
 137                                                         }
 138
 139                                                         /* Here 'param' doesn't have the channel on it yet */
 140                                                         redirects->push_back(BanRedirectEntry(mask[CHAN].c_str(), param.c_str()));
 141
 142                                                         /* Now it does */
 143                                                         param.append(mask[CHAN]);
 144                                                 }
 145                                                 else
 146                                                 {
 147                                                         /* Removing a ban, if there's no extensible there are no redirecting bans and we're fine. */
 148                                                         if(channel->GetExt("banredirects", redirects))
 149                                                         {
 150                                                                 /* But there were, so we need to remove the matching one if there is one */
 151
 152                                                                 for(BanRedirectList::iterator redir = redirects->begin(); redir != redirects->end(); redir++)
 153                                                                 {
 154                                                                         /* Ugly as fuck */
 155                                                                         if((irc::string(redir->targetchan.c_str()) == irc::string(mask[CHAN].c_str())) && (irc::string(redir->banmask.c_str()) == irc::string(param.c_str())))
 156                                                                         {
 157                                                                                 redirects->erase(redir);
 158
 159                                                                                 if(redirects->empty())
 160                                                                                 {
 161                                                                                         delete redirects;
 162                                                                                         channel->Shrink("banredirects");
 163                                                                                 }
 164
 165                                                                                 break;
 166                                                                         }
 167                                                                 }
 168                                                         }
 169
 170                                                         /* Append the channel so the default +b handler can remove the entry too */
 171                                                         param.append(mask[CHAN]);
 172                                                 }
 173                                         }
 174                                 }
 175                                 else
 176                                 {
 177                                         source->WriteNumeric(403, "%s %s :Invalid channel name in redirection (%s)", source->nick.c_str(), channel->name.c_str(), mask[CHAN].c_str());
 178                                         return false;
 179                                 }
 180                         }
 181                 }
 182
 183                 return true;
 184         }
 185 };
 186
 187 class ModuleBanRedirect : public Module
 188 {
 189         BanRedirect* re;
 190         bool nofollow;
 191         Module* ExceptionModule;
 192
 193  public:
 194         ModuleBanRedirect(InspIRCd* Me)
 195         : Module(Me)
 196         {
 197                 re = new BanRedirect(Me);
 198                 nofollow = false;
 199
 200                 if(!ServerInstance->Modes->AddModeWatcher(re))
 201                 {
 202                         delete re;
 203                         throw ModuleException("Could not add mode watcher");
 204                 }
 205
 206                 OnRehash(NULL, "");
 207
 208                 Implementation list[] = { I_OnRehash, I_OnUserPreJoin, I_OnChannelDelete, I_OnCleanup };
 209                 Me->Modules->Attach(list, this, 4);
 210
 211         }
 212
 213         virtual void OnChannelDelete(Channel* chan)
 214         {
 215                 OnCleanup(TYPE_CHANNEL, chan);
 216         }
 217
 218         virtual void OnCleanup(int target_type, void* item)
 219         {
 220                 if(target_type == TYPE_CHANNEL)
 221                 {
 222                         Channel* chan = static_cast<Channel*>(item);
 223                         BanRedirectList* redirects;
 224
 225                         if(chan->GetExt("banredirects", redirects))
 226                         {
 227                                 irc::modestacker modestack(ServerInstance, false);
 228                                 StringDeque stackresult;
 229                                 std::vector<std::string> mode_junk;
 230                                 mode_junk.push_back(chan->name);
 231
 232                                 for(BanRedirectList::iterator i = redirects->begin(); i != redirects->end(); i++)
 233                                 {
 234                                         modestack.Push('b', i->targetchan.insert(0, i->banmask));
 235                                 }
 236
 237                                 for(BanRedirectList::iterator i = redirects->begin(); i != redirects->end(); i++)
 238                                 {
 239                                         modestack.PushPlus();
 240                                         modestack.Push('b', i->banmask);
 241                                 }
 242
 243                                 while(modestack.GetStackedLine(stackresult))
 244                                 {
 245                                         for(StringDeque::size_type i = 0; i < stackresult.size(); i++)
 246                                         {
 247                                                 mode_junk.push_back(stackresult[i]);
 248                                         }
 249
 250                                         ServerInstance->SendMode(mode_junk, ServerInstance->FakeClient);
 251                                 }
 252
 253                                 delete redirects;
 254                                 chan->Shrink("banredirects");
 255                         }
 256                 }
 257         }
 258
 259         virtual void OnRehash(User* user, const std::string &param)
 260         {
 261                 ExceptionModule = ServerInstance->Modules->Find("m_banexception.so");
 262         }
 263
 264         virtual int OnUserPreJoin(User* user, Channel* chan, const char* cname, std::string &privs, const std::string &keygiven)
 265         {
 266                 /* This prevents recursion when a user sets multiple ban redirects in a chain
 267                  * (thanks Potter)
 268                  */
 269                 if (nofollow)
 270                         return 0;
 271
 272                 /* Return 1 to prevent the join, 0 to allow it */
 273                 if (chan)
 274                 {
 275                         BanRedirectList* redirects;
 276
 277                         if(chan->GetExt("banredirects", redirects))
 278                         {
 279                                 /* We actually had some ban redirects to check */
 280
 281                                 /* This was replaced with user->MakeHostIP() when I had a snprintf(), but MakeHostIP() doesn't seem to add the nick.
 282                                  * Maybe we should have a GetFullIPHost() or something to match GetFullHost() and GetFullRealHost?
 283                                  */
 284
 285                                 if (ExceptionModule)
 286                                 {
 287                                         ListModeRequest n(this, ExceptionModule, user, chan);
 288                                         /* Users with ban exceptions are allowed to join without being redirected */
 289                                         if (n.Send())
 290                                                 return 0;
 291                                 }
 292
 293                                 std::string ipmask(user->nick);
 294                                 ipmask.append(1, '!').append(user->MakeHostIP());
 295
 296                                 for(BanRedirectList::iterator redir = redirects->begin(); redir != redirects->end(); redir++)
 297                                 {
 298                                         if(InspIRCd::Match(user->GetFullRealHost(), redir->banmask) || InspIRCd::Match(user->GetFullHost(), redir->banmask) || InspIRCd::MatchCIDR(ipmask, redir->banmask))
 299                                         {
 300                                                 /* tell them they're banned and are being transferred */
 301                                                 Channel* destchan = ServerInstance->FindChan(redir->targetchan);
 302                                                 std::string destlimit;
 303
 304                                                 if (destchan)
 305                                                         destlimit = destchan->GetModeParameter('l');
 306
 307                                                 if(destchan && ServerInstance->Modules->Find("m_redirect.so") && destchan->IsModeSet('L') && !destlimit.empty() && (destchan->GetUserCounter() >= atoi(destlimit.c_str())))
 308                                                 {
 309                                                         user->WriteNumeric(474, "%s %s :Cannot join channel (You are banned)", user->nick.c_str(), chan->name.c_str());
 310                                                         return 1;
 311                                                 }
 312                                                 else
 313                                                 {
 314                                                         user->WriteNumeric(474, "%s %s :Cannot join channel (You are banned)", user->nick.c_str(), chan->name.c_str());
 315                                                         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());
 316                                                         nofollow = true;
 317                                                         Channel::JoinUser(ServerInstance, user, redir->targetchan.c_str(), false, "", false, ServerInstance->Time());
 318                                                         nofollow = false;
 319                                                         return 1;
 320                                                 }
 321                                         }
 322                                 }
 323                         }
 324                 }
 325                 return 0;
 326         }
 327
 328         virtual ~ModuleBanRedirect()
 329         {
 330                 ServerInstance->Modes->DelModeWatcher(re);
 331                 delete re;
 332         }
 333
 334         virtual Version GetVersion()
 335         {
 336                 return Version("$Id$", VF_COMMON | VF_VENDOR, API_VERSION);
 337         }
 338
 339         void Prioritize()
 340         {
 341                 Module* banex = ServerInstance->Modules->Find("m_banexception.so");
 342                 ServerInstance->Modules->SetPriority(this, I_OnUserPreJoin, PRIO_BEFORE, &banex);
 343         }
 344 };
 345
 346 MODULE_INIT(ModuleBanRedirect)