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 : public classbase
  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, bool)
  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 (param.length() >= 2 && param[1] == ':')
  66                                 return true;
  67
  68                         if(adding && (channel->bans.size() > static_cast<unsigned>(maxbans)))
  69                         {
  70                                 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);
  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(!IS_LOCAL(source) || Srv->IsChannel(mask[CHAN].c_str(), ServerInstance->Config->Limits.ChanMax))
 121                                 {
 122                                         if (assign(channel->name) == mask[CHAN])
 123                                         {
 124                                                 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());
 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->WriteNumeric(403, "%s %s :Invalid channel name in redirection (%s)", source->nick.c_str(), channel->name.c_str(), 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         bool nofollow;
 190         Module* ExceptionModule;
 191
 192  public:
 193         ModuleBanRedirect(InspIRCd* Me)
 194         : Module(Me)
 195         {
 196                 re = new BanRedirect(Me);
 197                 nofollow = false;
 198
 199                 if(!ServerInstance->Modes->AddModeWatcher(re))
 200                 {
 201                         delete re;
 202                         throw ModuleException("Could not add mode watcher");
 203                 }
 204
 205                 OnRehash(NULL, "");
 206
 207                 Implementation list[] = { I_OnRehash, I_OnUserPreJoin, I_OnChannelDelete, I_OnCleanup };
 208                 Me->Modules->Attach(list, this, 4);
 209
 210         }
 211
 212         virtual void OnChannelDelete(Channel* chan)
 213         {
 214                 OnCleanup(TYPE_CHANNEL, chan);
 215         }
 216
 217         virtual void OnCleanup(int target_type, void* item)
 218         {
 219                 if(target_type == TYPE_CHANNEL)
 220                 {
 221                         Channel* chan = static_cast<Channel*>(item);
 222                         BanRedirectList* redirects;
 223
 224                         if(chan->GetExt("banredirects", redirects))
 225                         {
 226                                 irc::modestacker modestack(ServerInstance, false);
 227                                 StringDeque stackresult;
 228                                 std::vector<std::string> mode_junk;
 229                                 mode_junk.push_back(chan->name);
 230
 231                                 for(BanRedirectList::iterator i = redirects->begin(); i != redirects->end(); i++)
 232                                 {
 233                                         modestack.Push('b', i->targetchan.insert(0, i->banmask));
 234                                 }
 235
 236                                 for(BanRedirectList::iterator i = redirects->begin(); i != redirects->end(); i++)
 237                                 {
 238                                         modestack.PushPlus();
 239                                         modestack.Push('b', i->banmask);
 240                                 }
 241
 242                                 while(modestack.GetStackedLine(stackresult))
 243                                 {
 244                                         for(StringDeque::size_type i = 0; i < stackresult.size(); i++)
 245                                         {
 246                                                 mode_junk.push_back(stackresult[i]);
 247                                         }
 248
 249                                         ServerInstance->SendMode(mode_junk, ServerInstance->FakeClient);
 250                                 }
 251
 252                                 delete redirects;
 253                                 chan->Shrink("banredirects");
 254                         }
 255                 }
 256         }
 257
 258         virtual void OnRehash(User* user, const std::string &param)
 259         {
 260                 ExceptionModule = ServerInstance->Modules->Find("m_banexception.so");
 261         }
 262
 263         virtual int OnUserPreJoin(User* user, Channel* chan, const char* cname, std::string &privs, const std::string &keygiven)
 264         {
 265                 /* This prevents recursion when a user sets multiple ban redirects in a chain
 266                  * (thanks Potter)
 267                  */
 268                 if (nofollow)
 269                         return 0;
 270
 271                 /* Return 1 to prevent the join, 0 to allow it */
 272                 if (chan)
 273                 {
 274                         BanRedirectList* redirects;
 275
 276                         if(chan->GetExt("banredirects", redirects))
 277                         {
 278                                 /* We actually had some ban redirects to check */
 279
 280                                 /* This was replaced with user->MakeHostIP() when I had a snprintf(), but MakeHostIP() doesn't seem to add the nick.
 281                                  * Maybe we should have a GetFullIPHost() or something to match GetFullHost() and GetFullRealHost?
 282                                  */
 283
 284                                 if (ExceptionModule)
 285                                 {
 286                                         ListModeRequest n(this, ExceptionModule, user, chan);
 287                                         /* Users with ban exceptions are allowed to join without being redirected */
 288                                         if (n.Send())
 289                                                 return 0;
 290                                 }
 291
 292                                 std::string ipmask(user->nick);
 293                                 ipmask.append(1, '!').append(user->MakeHostIP());
 294
 295                                 for(BanRedirectList::iterator redir = redirects->begin(); redir != redirects->end(); redir++)
 296                                 {
 297                                         if(InspIRCd::Match(user->GetFullRealHost(), redir->banmask) || InspIRCd::Match(user->GetFullHost(), redir->banmask) || InspIRCd::MatchCIDR(ipmask, redir->banmask))
 298                                         {
 299                                                 /* tell them they're banned and are being transferred */
 300                                                 Channel* destchan = ServerInstance->FindChan(redir->targetchan);
 301                                                 std::string destlimit;
 302
 303                                                 if (destchan)
 304                                                         destlimit = destchan->GetModeParameter('l');
 305
 306                                                 if(destchan && ServerInstance->Modules->Find("m_redirect.so") && destchan->IsModeSet('L') && !destlimit.empty() && (destchan->GetUserCounter() >= atoi(destlimit.c_str())))
 307                                                 {
 308                                                         user->WriteNumeric(474, "%s %s :Cannot join channel (You are banned)", user->nick.c_str(), chan->name.c_str());
 309                                                         return 1;
 310                                                 }
 311                                                 else
 312                                                 {
 313                                                         user->WriteNumeric(474, "%s %s :Cannot join channel (You are banned)", user->nick.c_str(), chan->name.c_str());
 314                                                         user->WriteNumeric(470, "%s :You are being automatically redirected to %s", user->nick.c_str(), redir->targetchan.c_str());
 315                                                         nofollow = true;
 316                                                         Channel::JoinUser(ServerInstance, user, redir->targetchan.c_str(), false, "", false, ServerInstance->Time());
 317                                                         nofollow = false;
 318                                                         return 1;
 319                                                 }
 320                                         }
 321                                 }
 322                         }
 323                 }
 324                 return 0;
 325         }
 326
 327         virtual ~ModuleBanRedirect()
 328         {
 329                 ServerInstance->Modes->DelModeWatcher(re);
 330                 delete re;
 331         }
 332
 333         virtual Version GetVersion()
 334         {
 335                 return Version(1, 0, 0, 0, VF_COMMON | VF_VENDOR, API_VERSION);
 336         }
 337
 338         void Prioritize()
 339         {
 340                 Module* banex = ServerInstance->Modules->Find("m_banexception.so");
 341                 ServerInstance->Modules->SetPriority(this, I_OnUserPreJoin, PRIO_BEFORE, &banex);
 342         }
 343 };
 344
 345 MODULE_INIT(ModuleBanRedirect)