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 "mode.h"
  15 #include "users.h"
  16 #include "channels.h"
  17 #include "modules.h"
  18 #include "inspircd.h"
  19
  20 /* $ModDesc: Allows an extended ban (+b) syntax redirecting banned users to another channel */
  21
  22 /* Originally written by Om, January 2007
  23  */
  24
  25 class BanRedirectEntry
  26 {
  27  public:
  28         std::string targetchan;
  29         std::string banmask;
  30
  31         BanRedirectEntry(const std::string &target = "", const std::string &mask = "")
  32         : targetchan(target), banmask(mask)
  33         {
  34         }
  35 };
  36
  37 typedef std::vector<BanRedirectEntry> BanRedirectList;
  38 typedef std::deque<std::string> StringDeque;
  39
  40 class BanRedirect : public ModeWatcher
  41 {
  42  private:
  43         InspIRCd* Srv;
  44  public:
  45         BanRedirect(InspIRCd* Instance)
  46         : ModeWatcher(Instance, 'b', MODETYPE_CHANNEL), Srv(Instance)
  47         {
  48         }
  49
  50         bool BeforeMode(userrec* source, userrec* dest, chanrec* channel, std::string &param, bool adding, ModeType type)
  51         {
  52                 /* nick!ident@host -> nick!ident@host
  53                  * nick!ident@host#chan -> nick!ident@host#chan
  54                  * nick@host#chan -> nick!*@host#chan
  55                  * nick!ident#chan -> nick!ident@*#chan
  56                  * nick#chan -> nick!*@*#chan
  57                  */
  58
  59                 if(channel && (type == MODETYPE_CHANNEL) && param.length())
  60                 {
  61                         BanRedirectList* redirects;
  62
  63                         std::string mask[4];
  64                         enum { NICK, IDENT, HOST, CHAN } current = NICK;
  65                         std::string::iterator start_pos = param.begin();
  66                         long maxbans = channel->GetMaxBans();
  67
  68                         if(channel->bans.size() > static_cast<unsigned>(maxbans))
  69                         {
  70                                 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);
  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                                                 mask[current].assign(start_pos, curr);
  90                                                 current = CHAN;
  91                                                 start_pos = curr;
  92                                                 break;
  93                                 }
  94                         }
  95
  96                         if(mask[current].empty())
  97                         {
  98                                 mask[current].assign(start_pos, param.end());
  99                         }
 100
 101                         /* nick@host wants to be changed to *!nick@host rather than nick!*@host... */
 102                         if(mask[NICK].length() && mask[HOST].length() && mask[IDENT].empty())
 103                         {
 104                                 /* std::string::swap() is fast - it runs in constant time */
 105                                 mask[NICK].swap(mask[IDENT]);
 106                         }
 107
 108                         for(int i = 0; i < 3; i++)
 109                         {
 110                                 if(mask[i].empty())
 111                                 {
 112                                         mask[i].assign("*");
 113                                 }
 114                         }
 115
 116                         param.assign(mask[NICK]).append(1, '!').append(mask[IDENT]).append(1, '@').append(mask[HOST]);
 117
 118                         if(mask[CHAN].length())
 119                         {
 120                                 if(Srv->IsChannel(mask[CHAN].c_str()))
 121                                 {
 122                                         if(irc::string(channel->name) == irc::string(mask[CHAN].c_str()))
 123                                         {
 124                                                 source->WriteServ("690 %s %s :You cannot set a ban redirection to the channel the ban is on", source->nick, channel->name);
 125                                                 return false;
 126                                         }
 127                                         else
 128                                         {
 129                                                 if(adding)
 130                                                 {
 131                                                         /* It's a properly valid redirecting ban, and we're adding it */
 132                                                         if(!channel->GetExt("banredirects", redirects))
 133                                                         {
 134                                                                 redirects = new BanRedirectList;
 135                                                                 channel->Extend("banredirects", redirects);
 136                                                         }
 137
 138                                                         /* Here 'param' doesn't have the channel on it yet */
 139                                                         redirects->push_back(BanRedirectEntry(mask[CHAN].c_str(), param.c_str()));
 140
 141                                                         /* Now it does */
 142                                                         param.append(mask[CHAN]);
 143                                                 }
 144                                                 else
 145                                                 {
 146                                                         /* Removing a ban, if there's no extensible there are no redirecting bans and we're fine. */
 147                                                         if(channel->GetExt("banredirects", redirects))
 148                                                         {
 149                                                                 /* But there were, so we need to remove the matching one if there is one */
 150
 151                                                                 for(BanRedirectList::iterator redir = redirects->begin(); redir != redirects->end(); redir++)
 152                                                                 {
 153                                                                         /* Ugly as fuck */
 154                                                                         if((irc::string(redir->targetchan.c_str()) == irc::string(mask[CHAN].c_str())) && (irc::string(redir->banmask.c_str()) == irc::string(param.c_str())))
 155                                                                         {
 156                                                                                 redirects->erase(redir);
 157
 158                                                                                 if(redirects->empty())
 159                                                                                 {
 160                                                                                         DELETE(redirects);
 161                                                                                         channel->Shrink("banredirects");
 162                                                                                 }
 163
 164                                                                                 break;
 165                                                                         }
 166                                                                 }
 167                                                         }
 168
 169                                                         /* Append the channel so the default +b handler can remove the entry too */
 170                                                         param.append(mask[CHAN]);
 171                                                 }
 172                                         }
 173                                 }
 174                                 else
 175                                 {
 176                                         source->WriteServ("403 %s %s :Invalid channel name in redirection (%s)", source->nick, channel->name, mask[CHAN].c_str());
 177                                         return false;
 178                                 }
 179                         }
 180                 }
 181
 182                 return true;
 183         }
 184 };
 185
 186 class ModuleBanRedirect : public Module
 187 {
 188         BanRedirect* re;
 189         InspIRCd* Srv;
 190         bool nofollow;
 191
 192  public:
 193         ModuleBanRedirect(InspIRCd* Me)
 194         : Module(Me), Srv(Me)
 195         {
 196                 re = new BanRedirect(Me);
 197                 nofollow = false;
 198
 199                 if(!Srv->AddModeWatcher(re))
 200                         throw ModuleException("Could not add mode watcher");
 201         }
 202
 203         void Implements(char* List)
 204         {
 205                 List[I_OnUserPreJoin] = List[I_OnChannelDelete] = List[I_OnCleanup] = 1;
 206         }
 207
 208         virtual void OnChannelDelete(chanrec* chan)
 209         {
 210                 OnCleanup(TYPE_CHANNEL, chan);
 211         }
 212
 213         virtual void OnCleanup(int target_type, void* item)
 214         {
 215                 if(target_type == TYPE_CHANNEL)
 216                 {
 217                         chanrec* chan = static_cast<chanrec*>(item);
 218                         BanRedirectList* redirects;
 219
 220                         if(chan->GetExt("banredirects", redirects))
 221                         {
 222                                 irc::modestacker modestack(false);
 223                                 StringDeque stackresult;
 224                                 const char* mode_junk[MAXMODES+1];
 225                                 userrec* myhorriblefakeuser = new userrec(Srv);
 226                                 myhorriblefakeuser->SetFd(FD_MAGIC_NUMBER);
 227
 228                                 mode_junk[0] = chan->name;
 229
 230                                 for(BanRedirectList::iterator i = redirects->begin(); i != redirects->end(); i++)
 231                                 {
 232                                         modestack.Push('b', i->targetchan.insert(0, i->banmask));
 233                                 }
 234
 235                                 for(BanRedirectList::iterator i = redirects->begin(); i != redirects->end(); i++)
 236                                 {
 237                                         modestack.PushPlus();
 238                                         modestack.Push('b', i->banmask);
 239                                 }
 240
 241                                 while(modestack.GetStackedLine(stackresult))
 242                                 {
 243                                         for(StringDeque::size_type i = 0; i < stackresult.size(); i++)
 244                                         {
 245                                                 mode_junk[i+1] = stackresult[i].c_str();
 246                                         }
 247
 248                                         Srv->SendMode(mode_junk, stackresult.size() + 1, myhorriblefakeuser);
 249                                 }
 250
 251                                 DELETE(myhorriblefakeuser);
 252                                 DELETE(redirects);
 253                                 chan->Shrink("banredirects");
 254                         }
 255                 }
 256         }
 257
 258         virtual int OnUserPreJoin(userrec* user, chanrec* chan, const char* cname, std::string &privs)
 259         {
 260                 /* This prevents recursion when a user sets multiple ban redirects in a chain
 261                  * (thanks Potter)
 262                  */
 263                 if (nofollow)
 264                         return 0;
 265
 266                 /* Return 1 to prevent the join, 0 to allow it */
 267                 if (chan)
 268                 {
 269                         BanRedirectList* redirects;
 270
 271                         if(chan->GetExt("banredirects", redirects))
 272                         {
 273                                 /* We actually had some ban redirects to check */
 274
 275                                 /* This was replaced with user->MakeHostIP() when I had a snprintf(), but MakeHostIP() doesn't seem to add the nick.
 276                                  * Maybe we should have a GetFullIPHost() or something to match GetFullHost() and GetFullRealHost?
 277                                  */
 278                                 std::string ipmask(user->nick);
 279                                 ipmask.append(1, '!').append(user->MakeHostIP());
 280
 281                                 for(BanRedirectList::iterator redir = redirects->begin(); redir != redirects->end(); redir++)
 282                                 {
 283                                         if(Srv->MatchText(user->GetFullRealHost(), redir->banmask) || Srv->MatchText(user->GetFullHost(), redir->banmask) || Srv->MatchText(ipmask, redir->banmask))
 284                                         {
 285                                                 /* tell them they're banned and are being transferred */
 286                                                 chanrec* destchan = Srv->FindChan(redir->targetchan);
 287
 288                                                 if(destchan && Srv->FindModule("m_redirect.so") && destchan->IsModeSet('L') && destchan->limit && (destchan->GetUserCounter() >= destchan->limit))
 289                                                 {
 290                                                         user->WriteServ("474 %s %s :Cannot join channel (You are banned)", user->nick, chan->name);
 291                                                         return 1;
 292                                                 }
 293                                                 else
 294                                                 {
 295                                                         user->WriteServ("470 %s :You are banned from %s. You are being automatically redirected to %s", user->nick, chan->name, redir->targetchan.c_str());
 296                                                         nofollow = true;
 297                                                         chanrec::JoinUser(Srv, user, redir->targetchan.c_str(), false, "", ServerInstance->Time(true));
 298                                                         nofollow = false;
 299                                                         return 1;
 300                                                 }
 301                                         }
 302                                 }
 303                         }
 304                 }
 305                 return 0;
 306         }
 307
 308         virtual ~ModuleBanRedirect()
 309         {
 310                 Srv->Modes->DelModeWatcher(re);
 311                 DELETE(re);
 312         }
 313
 314         virtual Version GetVersion()
 315         {
 316                 return Version(1, 0, 0, 0, VF_COMMON | VF_VENDOR, API_VERSION);
 317         }
 318 };
 319
 320
 321 class ModuleBanRedirectFactory : public ModuleFactory
 322 {
 323  public:
 324         ModuleBanRedirectFactory()
 325         {
 326         }
 327
 328         ~ModuleBanRedirectFactory()
 329         {
 330         }
 331
 332         virtual Module * CreateModule(InspIRCd* Me)
 333         {
 334                 return new ModuleBanRedirect(Me);
 335         }
 336
 337 };
 338
 339
 340 extern "C" DllExport void * init_module( void )
 341 {
 342         return new ModuleBanRedirectFactory;
 343 }