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
  19 /* Originally written by Om, January 2008
  20  */
  21
  22 class BanRedirectEntry
  23 {
  24  public:
  25         std::string targetchan;
  26         std::string banmask;
  27
  28         BanRedirectEntry(const std::string &target = "", const std::string &mask = "")
  29         : targetchan(target), banmask(mask)
  30         {
  31         }
  32 };
  33
  34 typedef std::vector<BanRedirectEntry> BanRedirectList;
  35 typedef std::deque<std::string> StringDeque;
  36
  37 class BanRedirect : public ModeWatcher
  38 {
  39  private:
  40         InspIRCd* Srv;
  41  public:
  42         BanRedirect(InspIRCd* Instance)
  43         : ModeWatcher(Instance, 'b', MODETYPE_CHANNEL), Srv(Instance)
  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(adding && (channel->bans.size() > static_cast<unsigned>(maxbans)))
  66                         {
  67                                 source->WriteServ("478 %s %s :Channel ban list for %s is full (maximum entries for this channel is %d)", source->nick, channel->name, channel->name, maxbans);
  68                                 return false;
  69                         }
  70
  71                         for(std::string::iterator curr = start_pos; curr != param.end(); curr++)
  72                         {
  73                                 switch(*curr)
  74                                 {
  75                                         case '!':
  76                                                 mask[current].assign(start_pos, curr);
  77                                                 current = IDENT;
  78                                                 start_pos = curr+1;
  79                                                 break;
  80                                         case '@':
  81                                                 mask[current].assign(start_pos, curr);
  82                                                 current = HOST;
  83                                                 start_pos = curr+1;
  84                                                 break;
  85                                         case '#':
  86                                                 mask[current].assign(start_pos, curr);
  87                                                 current = CHAN;
  88                                                 start_pos = curr;
  89                                                 break;
  90                                 }
  91                         }
  92
  93                         if(mask[current].empty())
  94                         {
  95                                 mask[current].assign(start_pos, param.end());
  96                         }
  97
  98                         /* nick@host wants to be changed to *!nick@host rather than nick!*@host... */
  99                         if(mask[NICK].length() && mask[HOST].length() && mask[IDENT].empty())
 100                         {
 101                                 /* std::string::swap() is fast - it runs in constant time */
 102                                 mask[NICK].swap(mask[IDENT]);
 103                         }
 104
 105                         for(int i = 0; i < 3; i++)
 106                         {
 107                                 if(mask[i].empty())
 108                                 {
 109                                         mask[i].assign("*");
 110                                 }
 111                         }
 112
 113                         param.assign(mask[NICK]).append(1, '!').append(mask[IDENT]).append(1, '@').append(mask[HOST]);
 114
 115                         if(mask[CHAN].length())
 116                         {
 117                                 if(Srv->IsChannel(mask[CHAN].c_str()))
 118                                 {
 119                                         if(irc::string(channel->name) == irc::string(mask[CHAN].c_str()))
 120                                         {
 121                                                 source->WriteServ("690 %s %s :You cannot set a ban redirection to the channel the ban is on", source->nick, channel->name);
 122                                                 return false;
 123                                         }
 124                                         else
 125                                         {
 126                                                 if(adding)
 127                                                 {
 128                                                         /* It's a properly valid redirecting ban, and we're adding it */
 129                                                         if(!channel->GetExt("banredirects", redirects))
 130                                                         {
 131                                                                 redirects = new BanRedirectList;
 132                                                                 channel->Extend("banredirects", redirects);
 133                                                         }
 134
 135                                                         /* Here 'param' doesn't have the channel on it yet */
 136                                                         redirects->push_back(BanRedirectEntry(mask[CHAN].c_str(), param.c_str()));
 137
 138                                                         /* Now it does */
 139                                                         param.append(mask[CHAN]);
 140                                                 }
 141                                                 else
 142                                                 {
 143                                                         /* Removing a ban, if there's no extensible there are no redirecting bans and we're fine. */
 144                                                         if(channel->GetExt("banredirects", redirects))
 145                                                         {
 146                                                                 /* But there were, so we need to remove the matching one if there is one */
 147
 148                                                                 for(BanRedirectList::iterator redir = redirects->begin(); redir != redirects->end(); redir++)
 149                                                                 {
 150                                                                         /* Ugly as fuck */
 151                                                                         if((irc::string(redir->targetchan.c_str()) == irc::string(mask[CHAN].c_str())) && (irc::string(redir->banmask.c_str()) == irc::string(param.c_str())))
 152                                                                         {
 153                                                                                 redirects->erase(redir);
 154
 155                                                                                 if(redirects->empty())
 156                                                                                 {
 157                                                                                         delete redirects;
 158                                                                                         channel->Shrink("banredirects");
 159                                                                                 }
 160
 161                                                                                 break;
 162                                                                         }
 163                                                                 }
 164                                                         }
 165
 166                                                         /* Append the channel so the default +b handler can remove the entry too */
 167                                                         param.append(mask[CHAN]);
 168                                                 }
 169                                         }
 170                                 }
 171                                 else
 172                                 {
 173                                         source->WriteServ("403 %s %s :Invalid channel name in redirection (%s)", source->nick, channel->name, mask[CHAN].c_str());
 174                                         return false;
 175                                 }
 176                         }
 177                 }
 178
 179                 return true;
 180         }
 181 };
 182
 183 class ModuleBanRedirect : public Module
 184 {
 185         BanRedirect* re;
 186         bool nofollow;
 187         Module* ExceptionModule;
 188
 189  public:
 190         ModuleBanRedirect(InspIRCd* Me)
 191         : Module(Me)
 192         {
 193                 re = new BanRedirect(Me);
 194                 nofollow = false;
 195
 196                 if(!ServerInstance->AddModeWatcher(re))
 197                 {
 198                         delete re;
 199                         throw ModuleException("Could not add mode watcher");
 200                 }
 201
 202                 OnRehash(NULL, "");
 203
 204                 Implementation list[] = { I_OnRehash, I_OnUserPreJoin, I_OnChannelDelete, I_OnCleanup };
 205                 Me->Modules->Attach(list, this, sizeof(*list));
 206
 207         }
 208
 209         virtual void OnChannelDelete(Channel* chan)
 210         {
 211                 OnCleanup(TYPE_CHANNEL, chan);
 212         }
 213
 214         virtual void OnCleanup(int target_type, void* item)
 215         {
 216                 if(target_type == TYPE_CHANNEL)
 217                 {
 218                         Channel* chan = static_cast<Channel*>(item);
 219                         BanRedirectList* redirects;
 220
 221                         if(chan->GetExt("banredirects", redirects))
 222                         {
 223                                 irc::modestacker modestack(false);
 224                                 StringDeque stackresult;
 225                                 const char* mode_junk[MAXMODES+2];
 226
 227                                 mode_junk[0] = chan->name;
 228
 229                                 for(BanRedirectList::iterator i = redirects->begin(); i != redirects->end(); i++)
 230                                 {
 231                                         modestack.Push('b', i->targetchan.insert(0, i->banmask));
 232                                 }
 233
 234                                 for(BanRedirectList::iterator i = redirects->begin(); i != redirects->end(); i++)
 235                                 {
 236                                         modestack.PushPlus();
 237                                         modestack.Push('b', i->banmask);
 238                                 }
 239
 240                                 while(modestack.GetStackedLine(stackresult))
 241                                 {
 242                                         for(StringDeque::size_type i = 0; i < stackresult.size(); i++)
 243                                         {
 244                                                 mode_junk[i+1] = stackresult[i].c_str();
 245                                         }
 246
 247                                         ServerInstance->SendMode(mode_junk, stackresult.size() + 1, ServerInstance->FakeClient);
 248                                 }
 249
 250                                 delete redirects;
 251                                 chan->Shrink("banredirects");
 252                         }
 253                 }
 254         }
 255
 256         virtual void OnRehash(User* user, const std::string &param)
 257         {
 258                 ExceptionModule = ServerInstance->Modules->Find("m_banexception.so");
 259         }
 260
 261         virtual int OnUserPreJoin(User* user, Channel* chan, const char* cname, std::string &privs, bool synching = false)
 262         {
 263                 /* This prevents recursion when a user sets multiple ban redirects in a chain
 264                  * (thanks Potter)
 265                  */
 266                 if (nofollow)
 267                         return 0;
 268
 269                 /* Return 1 to prevent the join, 0 to allow it */
 270                 if (chan)
 271                 {
 272                         BanRedirectList* redirects;
 273
 274                         if(chan->GetExt("banredirects", redirects))
 275                         {
 276                                 /* We actually had some ban redirects to check */
 277
 278                                 /* This was replaced with user->MakeHostIP() when I had a snprintf(), but MakeHostIP() doesn't seem to add the nick.
 279                                  * Maybe we should have a GetFullIPHost() or something to match GetFullHost() and GetFullRealHost?
 280                                  */
 281
 282                                 if (ExceptionModule)
 283                                 {
 284                                         ListModeRequest n(this, ExceptionModule, user, chan);
 285                                         /* Users with ban exceptions are allowed to join without being redirected */
 286                                         if (n.Send())
 287                                                 return 0;
 288                                 }
 289
 290                                 std::string ipmask(user->nick);
 291                                 ipmask.append(1, '!').append(user->MakeHostIP());
 292
 293                                 for(BanRedirectList::iterator redir = redirects->begin(); redir != redirects->end(); redir++)
 294                                 {
 295                                         if(ServerInstance->MatchText(user->GetFullRealHost(), redir->banmask) || ServerInstance->MatchText(user->GetFullHost(), redir->banmask) || ServerInstance->MatchText(ipmask, redir->banmask))
 296                                         {
 297                                                 /* tell them they're banned and are being transferred */
 298                                                 Channel* destchan = ServerInstance->FindChan(redir->targetchan);
 299
 300                                                 if(destchan && ServerInstance->Modules->Find("m_redirect.so") && destchan->IsModeSet('L') && destchan->limit && (destchan->GetUserCounter() >= destchan->limit))
 301                                                 {
 302                                                         user->WriteServ("474 %s %s :Cannot join channel (You are banned)", user->nick, chan->name);
 303                                                         return 1;
 304                                                 }
 305                                                 else
 306                                                 {
 307                                                         user->WriteServ("474 %s %s :Cannot join channel (You are banned)", user->nick, chan->name);
 308                                                         user->WriteServ("470 %s :You are being automatically redirected to %s", user->nick, redir->targetchan.c_str());
 309                                                         nofollow = true;
 310                                                         Channel::JoinUser(ServerInstance, user, redir->targetchan.c_str(), false, "", false, ServerInstance->Time(true));
 311                                                         nofollow = false;
 312                                                         return 1;
 313                                                 }
 314                                         }
 315                                 }
 316                         }
 317                 }
 318                 return 0;
 319         }
 320
 321         virtual ~ModuleBanRedirect()
 322         {
 323                 ServerInstance->Modes->DelModeWatcher(re);
 324                 delete re;
 325         }
 326
 327         virtual Version GetVersion()
 328         {
 329                 return Version(1, 0, 0, 0, VF_COMMON | VF_VENDOR, API_VERSION);
 330         }
 331
 332         void Prioritize()
 333         {
 334                 Module* banex = ServerInstance->Modules->Find("m_banexception.so");
 335                 ServerInstance->Modules->SetPriority(this, I_OnUserPreJoin, PRIO_BEFORE, &banex);
 336         }
 337 };
 338
 339 MODULE_INIT(ModuleBanRedirect)