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 : 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  public:
  41         BanRedirect(InspIRCd* Instance)
  42         : ModeWatcher(Instance, 'b', MODETYPE_CHANNEL)
  43         {
  44         }
  45
  46         bool BeforeMode(User* source, User* dest, Channel* channel, std::string &param, bool adding, ModeType type, bool)
  47         {
  48                 /* nick!ident@host -> nick!ident@host
  49                  * nick!ident@host#chan -> nick!ident@host#chan
  50                  * nick@host#chan -> nick!*@host#chan
  51                  * nick!ident#chan -> nick!ident@*#chan
  52                  * nick#chan -> nick!*@*#chan
  53                  */
  54
  55                 if(channel && (type == MODETYPE_CHANNEL) && param.length())
  56                 {
  57                         BanRedirectList* redirects;
  58
  59                         std::string mask[4];
  60                         enum { NICK, IDENT, HOST, CHAN } current = NICK;
  61                         std::string::iterator start_pos = param.begin();
  62                         long maxbans = channel->GetMaxBans();
  63
  64                         if (param.length() >= 2 && param[1] == ':')
  65                                 return true;
  66
  67                         if(adding && (channel->bans.size() > static_cast<unsigned>(maxbans)))
  68                         {
  69                                 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);
  70                                 return false;
  71                         }
  72
  73                         for(std::string::iterator curr = start_pos; curr != param.end(); curr++)
  74                         {
  75                                 switch(*curr)
  76                                 {
  77                                         case '!':
  78                                                 mask[current].assign(start_pos, curr);
  79                                                 current = IDENT;
  80                                                 start_pos = curr+1;
  81                                                 break;
  82                                         case '@':
  83                                                 mask[current].assign(start_pos, curr);
  84                                                 current = HOST;
  85                                                 start_pos = curr+1;
  86                                                 break;
  87                                         case '#':
  88                                                 mask[current].assign(start_pos, curr);
  89                                                 current = CHAN;
  90                                                 start_pos = curr;
  91                                                 break;
  92                                 }
  93                         }
  94
  95                         if(mask[current].empty())
  96                         {
  97                                 mask[current].assign(start_pos, param.end());
  98                         }
  99
 100                         /* nick@host wants to be changed to *!nick@host rather than nick!*@host... */
 101                         if(mask[NICK].length() && mask[HOST].length() && mask[IDENT].empty())
 102                         {
 103                                 /* std::string::swap() is fast - it runs in constant time */
 104                                 mask[NICK].swap(mask[IDENT]);
 105                         }
 106
 107                         for(int i = 0; i < 3; i++)
 108                         {
 109                                 if(mask[i].empty())
 110                                 {
 111                                         mask[i].assign("*");
 112                                 }
 113                         }
 114
 115                         param.assign(mask[NICK]).append(1, '!').append(mask[IDENT]).append(1, '@').append(mask[HOST]);
 116
 117                         if(mask[CHAN].length())
 118                         {
 119                                 if (IS_LOCAL(source))
 120                                 {
 121                                         if (!ServerInstance->IsChannel(mask[CHAN].c_str(),  ServerInstance->Config->Limits.ChanMax))
 122                                         {
 123                                                 source->WriteNumeric(403, "%s %s :Invalid channel name in redirection (%s)", source->nick.c_str(), channel->name.c_str(), mask[CHAN].c_str());
 124                                                 return false;
 125                                         }
 126
 127                                         Channel *c = ServerInstance->FindChan(mask[CHAN].c_str());
 128                                         if (!c)
 129                                         {
 130                                                 source->WriteNumeric(690, "%s :Target channel %s must exist to be set as a redirect.",source->nick.c_str(),mask[CHAN].c_str());
 131                                                 return false;
 132                                         }
 133                                         else if (c->GetStatus(source) < STATUS_OP)
 134                                         {
 135                                                 source->WriteNumeric(690, "%s :You must be opped on %s to set it as a redirect.",source->nick.c_str(), mask[CHAN].c_str());
 136                                                 return false;
 137                                         }
 138
 139                                         if (assign(channel->name) == mask[CHAN])
 140                                         {
 141                                                 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());
 142                                                 return false;
 143                                         }
 144                                 }
 145
 146                                 if(adding)
 147                                 {
 148                                         /* It's a properly valid redirecting ban, and we're adding it */
 149                                         if(!channel->GetExt("banredirects", redirects))
 150                                         {
 151                                                 redirects = new BanRedirectList;
 152                                                 channel->Extend("banredirects", redirects);
 153                                         }
 154
 155                                         /* Here 'param' doesn't have the channel on it yet */
 156                                         redirects->push_back(BanRedirectEntry(mask[CHAN].c_str(), param.c_str()));
 157
 158                                         /* Now it does */
 159                                         param.append(mask[CHAN]);
 160                                 }
 161                                 else
 162                                 {
 163                                         /* Removing a ban, if there's no extensible there are no redirecting bans and we're fine. */
 164                                         if(channel->GetExt("banredirects", redirects))
 165                                         {
 166                                                 /* But there were, so we need to remove the matching one if there is one */
 167
 168                                                 for(BanRedirectList::iterator redir = redirects->begin(); redir != redirects->end(); redir++)
 169                                                 {
 170                                                         /* Ugly as fuck */
 171                                                         if((irc::string(redir->targetchan.c_str()) == irc::string(mask[CHAN].c_str())) && (irc::string(redir->banmask.c_str()) == irc::string(param.c_str())))
 172                                                         {
 173                                                                 redirects->erase(redir);
 174
 175                                                                 if(redirects->empty())
 176                                                                 {
 177                                                                         delete redirects;
 178                                                                         channel->Shrink("banredirects");
 179                                                                 }
 180
 181                                                                 break;
 182                                                         }
 183                                                 }
 184                                         }
 185
 186                                         /* Append the channel so the default +b handler can remove the entry too */
 187                                         param.append(mask[CHAN]);
 188                                 }
 189                         }
 190                 }
 191
 192                 return true;
 193         }
 194 };
 195
 196 class ModuleBanRedirect : public Module
 197 {
 198         BanRedirect re;
 199         bool nofollow;
 200         Module* ExceptionModule;
 201
 202  public:
 203         ModuleBanRedirect(InspIRCd* Me)
 204         : Module(Me), re(Me)
 205         {
 206                 nofollow = false;
 207
 208                 if(!ServerInstance->Modes->AddModeWatcher(&re))
 209                         throw ModuleException("Could not add mode watcher");
 210
 211                 OnRehash(NULL);
 212
 213                 Implementation list[] = { I_OnRehash, I_OnUserPreJoin, I_OnChannelDelete, I_OnCleanup };
 214                 Me->Modules->Attach(list, this, 4);
 215
 216         }
 217
 218         virtual void OnChannelDelete(Channel* chan)
 219         {
 220                 OnCleanup(TYPE_CHANNEL, chan);
 221         }
 222
 223         virtual void OnCleanup(int target_type, void* item)
 224         {
 225                 if(target_type == TYPE_CHANNEL)
 226                 {
 227                         Channel* chan = static_cast<Channel*>(item);
 228                         BanRedirectList* redirects;
 229
 230                         if(chan->GetExt("banredirects", redirects))
 231                         {
 232                                 irc::modestacker modestack(ServerInstance, false);
 233                                 StringDeque stackresult;
 234                                 std::vector<std::string> mode_junk;
 235                                 mode_junk.push_back(chan->name);
 236
 237                                 for(BanRedirectList::iterator i = redirects->begin(); i != redirects->end(); i++)
 238                                 {
 239                                         modestack.Push('b', i->targetchan.insert(0, i->banmask));
 240                                 }
 241
 242                                 for(BanRedirectList::iterator i = redirects->begin(); i != redirects->end(); i++)
 243                                 {
 244                                         modestack.PushPlus();
 245                                         modestack.Push('b', i->banmask);
 246                                 }
 247
 248                                 while(modestack.GetStackedLine(stackresult))
 249                                 {
 250                                         mode_junk.insert(mode_junk.end(), stackresult.begin(), stackresult.end());
 251                                         ServerInstance->SendMode(mode_junk, ServerInstance->FakeClient);
 252                                         mode_junk.erase(mode_junk.begin() + 1, mode_junk.end());
 253                                 }
 254
 255                                 delete redirects;
 256                                 chan->Shrink("banredirects");
 257                         }
 258                 }
 259         }
 260
 261         virtual void OnRehash(User* user)
 262         {
 263                 ExceptionModule = ServerInstance->Modules->Find("m_banexception.so");
 264         }
 265
 266         virtual int OnUserPreJoin(User* user, Channel* chan, const char* cname, std::string &privs, const std::string &keygiven)
 267         {
 268                 /* This prevents recursion when a user sets multiple ban redirects in a chain
 269                  * (thanks Potter)
 270                  */
 271                 if (nofollow)
 272                         return 0;
 273
 274                 /* Return 1 to prevent the join, 0 to allow it */
 275                 if (chan)
 276                 {
 277                         BanRedirectList* redirects;
 278
 279                         if(chan->GetExt("banredirects", redirects))
 280                         {
 281                                 /* We actually had some ban redirects to check */
 282
 283                                 /* This was replaced with user->MakeHostIP() when I had a snprintf(), but MakeHostIP() doesn't seem to add the nick.
 284                                  * Maybe we should have a GetFullIPHost() or something to match GetFullHost() and GetFullRealHost?
 285                                  */
 286
 287                                 if (ExceptionModule)
 288                                 {
 289                                         ListModeRequest n(this, ExceptionModule, user, chan);
 290                                         /* Users with ban exceptions are allowed to join without being redirected */
 291                                         if (n.Send())
 292                                                 return 0;
 293                                 }
 294
 295                                 std::string ipmask(user->nick);
 296                                 ipmask.append(1, '!').append(user->MakeHostIP());
 297
 298                                 for(BanRedirectList::iterator redir = redirects->begin(); redir != redirects->end(); redir++)
 299                                 {
 300                                         if(InspIRCd::Match(user->GetFullRealHost(), redir->banmask) || InspIRCd::Match(user->GetFullHost(), redir->banmask) || InspIRCd::MatchCIDR(ipmask, redir->banmask))
 301                                         {
 302                                                 /* tell them they're banned and are being transferred */
 303                                                 Channel* destchan = ServerInstance->FindChan(redir->targetchan);
 304                                                 std::string destlimit;
 305
 306                                                 if (destchan)
 307                                                         destlimit = destchan->GetModeParameter('l');
 308
 309                                                 if(destchan && ServerInstance->Modules->Find("m_redirect.so") && destchan->IsModeSet('L') && !destlimit.empty() && (destchan->GetUserCounter() >= atoi(destlimit.c_str())))
 310                                                 {
 311                                                         user->WriteNumeric(474, "%s %s :Cannot join channel (You are banned)", user->nick.c_str(), chan->name.c_str());
 312                                                         return 1;
 313                                                 }
 314                                                 else
 315                                                 {
 316                                                         user->WriteNumeric(474, "%s %s :Cannot join channel (You are banned)", user->nick.c_str(), chan->name.c_str());
 317                                                         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());
 318                                                         nofollow = true;
 319                                                         Channel::JoinUser(ServerInstance, user, redir->targetchan.c_str(), false, "", false, ServerInstance->Time());
 320                                                         nofollow = false;
 321                                                         return 1;
 322                                                 }
 323                                         }
 324                                 }
 325                         }
 326                 }
 327                 return 0;
 328         }
 329
 330         virtual ~ModuleBanRedirect()
 331         {
 332                 ServerInstance->Modes->DelModeWatcher(&re);
 333         }
 334
 335         virtual Version GetVersion()
 336         {
 337                 return Version("$Id$", VF_COMMON|VF_VENDOR, API_VERSION);
 338         }
 339
 340         void Prioritize()
 341         {
 342                 Module* banex = ServerInstance->Modules->Find("m_banexception.so");
 343                 ServerInstance->Modules->SetPriority(this, I_OnUserPreJoin, PRIORITY_BEFORE, &banex);
 344         }
 345 };
 346
 347 MODULE_INIT(ModuleBanRedirect)