src/modules/m_banredirect.cpp

   1 /*       +------------------------------------+
   2  *       | Inspire Internet Relay Chat Daemon |
   3  *       +------------------------------------+
   4  *
   5  *  InspIRCd: (C) 2002-2007 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 "mode.h"
  16 #include "users.h"
  17 #include "channels.h"
  18 #include "modules.h"
  19 #include "u_listmode.h"
  20
  21 /* $ModDesc: Allows an extended ban (+b) syntax redirecting banned users to another channel */
  22
  23 /* Originally written by Om, January 2007
  24  */
  25
  26 class BanRedirectEntry
  27 {
  28  public:
  29         std::string targetchan;
  30         std::string banmask;
  31
  32         BanRedirectEntry(const std::string &target = "", const std::string &mask = "")
  33         : targetchan(target), banmask(mask)
  34         {
  35         }
  36 };
  37
  38 typedef std::vector<BanRedirectEntry> BanRedirectList;
  39 typedef std::deque<std::string> StringDeque;
  40
  41 class BanRedirect : public ModeWatcher
  42 {
  43  private:
  44         InspIRCd* Srv;
  45  public:
  46         BanRedirect(InspIRCd* Instance)
  47         : ModeWatcher(Instance, 'b', MODETYPE_CHANNEL), Srv(Instance)
  48         {
  49         }
  50
  51         bool BeforeMode(userrec* source, userrec* dest, chanrec* channel, std::string &param, bool adding, ModeType type)
  52         {
  53                 /* nick!ident@host -> nick!ident@host
  54                  * nick!ident@host#chan -> nick!ident@host#chan
  55                  * nick@host#chan -> nick!*@host#chan
  56                  * nick!ident#chan -> nick!ident@*#chan
  57                  * nick#chan -> nick!*@*#chan
  58                  */
  59
  60                 if(channel && (type == MODETYPE_CHANNEL) && param.length())
  61                 {
  62                         BanRedirectList* redirects;
  63
  64                         std::string mask[4];
  65                         enum { NICK, IDENT, HOST, CHAN } current = NICK;
  66                         std::string::iterator start_pos = param.begin();
  67                         long maxbans = channel->GetMaxBans();
  68
  69                         if(channel->bans.size() > static_cast<unsigned>(maxbans))
  70                         {
  71                                 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);
  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(Srv->IsChannel(mask[CHAN].c_str()))
 122                                 {
 123                                         if(irc::string(channel->name) == irc::string(mask[CHAN].c_str()))
 124                                         {
 125                                                 source->WriteServ("690 %s %s :You cannot set a ban redirection to the channel the ban is on", source->nick, channel->name);
 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->WriteServ("403 %s %s :Invalid channel name in redirection (%s)", source->nick, channel->name, 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->AddModeWatcher(re))
 201                         throw ModuleException("Could not add mode watcher");
 202
 203                 OnRehash(NULL, "");
 204         }
 205
 206         void Implements(char* List)
 207         {
 208                 List[I_OnRehash] = List[I_OnUserPreJoin] = List[I_OnChannelDelete] = List[I_OnCleanup] = 1;
 209         }
 210
 211         virtual void OnChannelDelete(chanrec* chan)
 212         {
 213                 OnCleanup(TYPE_CHANNEL, chan);
 214         }
 215
 216         virtual void OnCleanup(int target_type, void* item)
 217         {
 218                 if(target_type == TYPE_CHANNEL)
 219                 {
 220                         chanrec* chan = static_cast<chanrec*>(item);
 221                         BanRedirectList* redirects;
 222
 223                         if(chan->GetExt("banredirects", redirects))
 224                         {
 225                                 irc::modestacker modestack(false);
 226                                 StringDeque stackresult;
 227                                 const char* mode_junk[MAXMODES+2];
 228                                 userrec* myhorriblefakeuser = new userrec(ServerInstance);
 229                                 myhorriblefakeuser->SetFd(FD_MAGIC_NUMBER);
 230
 231                                 mode_junk[0] = chan->name;
 232
 233                                 for(BanRedirectList::iterator i = redirects->begin(); i != redirects->end(); i++)
 234                                 {
 235                                         modestack.Push('b', i->targetchan.insert(0, i->banmask));
 236                                 }
 237
 238                                 for(BanRedirectList::iterator i = redirects->begin(); i != redirects->end(); i++)
 239                                 {
 240                                         modestack.PushPlus();
 241                                         modestack.Push('b', i->banmask);
 242                                 }
 243
 244                                 while(modestack.GetStackedLine(stackresult))
 245                                 {
 246                                         for(StringDeque::size_type i = 0; i < stackresult.size(); i++)
 247                                         {
 248                                                 mode_junk[i+1] = stackresult[i].c_str();
 249                                         }
 250
 251                                         ServerInstance->SendMode(mode_junk, stackresult.size() + 1, myhorriblefakeuser);
 252                                 }
 253
 254                                 DELETE(myhorriblefakeuser);
 255                                 DELETE(redirects);
 256                                 chan->Shrink("banredirects");
 257                         }
 258                 }
 259         }
 260
 261         virtual void OnRehash(userrec* user, const std::string &param)
 262         {
 263                 ExceptionModule = ServerInstance->FindModule("m_banexception.so");
 264         }
 265
 266         virtual int OnUserPreJoin(userrec* user, chanrec* chan, const char* cname, std::string &privs)
 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(ServerInstance->MatchText(user->GetFullRealHost(), redir->banmask) || ServerInstance->MatchText(user->GetFullHost(), redir->banmask) || ServerInstance->MatchText(ipmask, redir->banmask))
 301                                         {
 302                                                 /* tell them they're banned and are being transferred */
 303                                                 chanrec* destchan = ServerInstance->FindChan(redir->targetchan);
 304
 305                                                 if(destchan && ServerInstance->FindModule("m_redirect.so") && destchan->IsModeSet('L') && destchan->limit && (destchan->GetUserCounter() >= destchan->limit))
 306                                                 {
 307                                                         user->WriteServ("474 %s %s :Cannot join channel (You are banned)", user->nick, chan->name);
 308                                                         return 1;
 309                                                 }
 310                                                 else
 311                                                 {
 312                                                         user->WriteServ("470 %s :You are banned from %s. You are being automatically redirected to %s", user->nick, chan->name, redir->targetchan.c_str());
 313                                                         nofollow = true;
 314                                                         chanrec::JoinUser(ServerInstance, user, redir->targetchan.c_str(), false, "", ServerInstance->Time(true));
 315                                                         nofollow = false;
 316                                                         return 1;
 317                                                 }
 318                                         }
 319                                 }
 320                         }
 321                 }
 322                 return 0;
 323         }
 324
 325         virtual ~ModuleBanRedirect()
 326         {
 327                 ServerInstance->Modes->DelModeWatcher(re);
 328                 DELETE(re);
 329         }
 330
 331         virtual Version GetVersion()
 332         {
 333                 return Version(1, 0, 0, 0, VF_COMMON | VF_VENDOR, API_VERSION);
 334         }
 335
 336         Priority Prioritize()
 337         {
 338                 return (Priority)ServerInstance->PriorityBefore("m_banexception.so");
 339         }
 340 };
 341
 342
 343 MODULE_INIT(ModuleBanRedirect);