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) || ServerInstance->IsChannel(mask[CHAN].c_str(), ServerInstance->Config->Limits.ChanMax))
 120                                 {
 121                                         if (assign(channel->name) == mask[CHAN])
 122                                         {
 123                                                 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());
 124                                                 return false;
 125                                         }
 126                                         else
 127                                         {
 128                                                 if(adding)
 129                                                 {
 130                                                         /* It's a properly valid redirecting ban, and we're adding it */
 131                                                         if(!channel->GetExt("banredirects", redirects))
 132                                                         {
 133                                                                 redirects = new BanRedirectList;
 134                                                                 channel->Extend("banredirects", redirects);
 135                                                         }
 136
 137                                                         /* Here 'param' doesn't have the channel on it yet */
 138                                                         redirects->push_back(BanRedirectEntry(mask[CHAN].c_str(), param.c_str()));
 139
 140                                                         /* Now it does */
 141                                                         param.append(mask[CHAN]);
 142                                                 }
 143                                                 else
 144                                                 {
 145                                                         /* Removing a ban, if there's no extensible there are no redirecting bans and we're fine. */
 146                                                         if(channel->GetExt("banredirects", redirects))
 147                                                         {
 148                                                                 /* But there were, so we need to remove the matching one if there is one */
 149
 150                                                                 for(BanRedirectList::iterator redir = redirects->begin(); redir != redirects->end(); redir++)
 151                                                                 {
 152                                                                         /* Ugly as fuck */
 153                                                                         if((irc::string(redir->targetchan.c_str()) == irc::string(mask[CHAN].c_str())) && (irc::string(redir->banmask.c_str()) == irc::string(param.c_str())))
 154                                                                         {
 155                                                                                 redirects->erase(redir);
 156
 157                                                                                 if(redirects->empty())
 158                                                                                 {
 159                                                                                         delete redirects;
 160                                                                                         channel->Shrink("banredirects");
 161                                                                                 }
 162
 163                                                                                 break;
 164                                                                         }
 165                                                                 }
 166                                                         }
 167
 168                                                         /* Append the channel so the default +b handler can remove the entry too */
 169                                                         param.append(mask[CHAN]);
 170                                                 }
 171                                         }
 172                                 }
 173                                 else
 174                                 {
 175                                         source->WriteNumeric(403, "%s %s :Invalid channel name in redirection (%s)", source->nick.c_str(), channel->name.c_str(), mask[CHAN].c_str());
 176                                         return false;
 177                                 }
 178                         }
 179                 }
 180
 181                 return true;
 182         }
 183 };
 184
 185 class ModuleBanRedirect : public Module
 186 {
 187         BanRedirect* re;
 188         bool nofollow;
 189         Module* ExceptionModule;
 190
 191  public:
 192         ModuleBanRedirect(InspIRCd* Me)
 193         : Module(Me)
 194         {
 195                 re = new BanRedirect(Me);
 196                 nofollow = false;
 197
 198                 if(!ServerInstance->Modes->AddModeWatcher(re))
 199                 {
 200                         delete re;
 201                         throw ModuleException("Could not add mode watcher");
 202                 }
 203
 204                 OnRehash(NULL, "");
 205
 206                 Implementation list[] = { I_OnRehash, I_OnUserPreJoin, I_OnChannelDelete, I_OnCleanup };
 207                 Me->Modules->Attach(list, this, 4);
 208
 209         }
 210
 211         virtual void OnChannelDelete(Channel* 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                         Channel* chan = static_cast<Channel*>(item);
 221                         BanRedirectList* redirects;
 222
 223                         if(chan->GetExt("banredirects", redirects))
 224                         {
 225                                 irc::modestacker modestack(ServerInstance, false);
 226                                 StringDeque stackresult;
 227                                 std::vector<std::string> mode_junk;
 228                                 mode_junk.push_back(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                                         mode_junk.insert(mode_junk.end(), stackresult.begin(), stackresult.end());
 244                                         ServerInstance->SendMode(mode_junk, ServerInstance->FakeClient);
 245                                         mode_junk.erase(mode_junk.begin() + 1, mode_junk.end());
 246                                 }
 247
 248                                 delete redirects;
 249                                 chan->Shrink("banredirects");
 250                         }
 251                 }
 252         }
 253
 254         virtual void OnRehash(User* user, const std::string &param)
 255         {
 256                 ExceptionModule = ServerInstance->Modules->Find("m_banexception.so");
 257         }
 258
 259         virtual int OnUserPreJoin(User* user, Channel* chan, const char* cname, std::string &privs, const std::string &keygiven)
 260         {
 261                 /* This prevents recursion when a user sets multiple ban redirects in a chain
 262                  * (thanks Potter)
 263                  */
 264                 if (nofollow)
 265                         return 0;
 266
 267                 /* Return 1 to prevent the join, 0 to allow it */
 268                 if (chan)
 269                 {
 270                         BanRedirectList* redirects;
 271
 272                         if(chan->GetExt("banredirects", redirects))
 273                         {
 274                                 /* We actually had some ban redirects to check */
 275
 276                                 /* This was replaced with user->MakeHostIP() when I had a snprintf(), but MakeHostIP() doesn't seem to add the nick.
 277                                  * Maybe we should have a GetFullIPHost() or something to match GetFullHost() and GetFullRealHost?
 278                                  */
 279
 280                                 if (ExceptionModule)
 281                                 {
 282                                         ListModeRequest n(this, ExceptionModule, user, chan);
 283                                         /* Users with ban exceptions are allowed to join without being redirected */
 284                                         if (n.Send())
 285                                                 return 0;
 286                                 }
 287
 288                                 std::string ipmask(user->nick);
 289                                 ipmask.append(1, '!').append(user->MakeHostIP());
 290
 291                                 for(BanRedirectList::iterator redir = redirects->begin(); redir != redirects->end(); redir++)
 292                                 {
 293                                         if(InspIRCd::Match(user->GetFullRealHost(), redir->banmask) || InspIRCd::Match(user->GetFullHost(), redir->banmask) || InspIRCd::MatchCIDR(ipmask, redir->banmask))
 294                                         {
 295                                                 /* tell them they're banned and are being transferred */
 296                                                 Channel* destchan = ServerInstance->FindChan(redir->targetchan);
 297                                                 std::string destlimit;
 298
 299                                                 if (destchan)
 300                                                         destlimit = destchan->GetModeParameter('l');
 301
 302                                                 if(destchan && ServerInstance->Modules->Find("m_redirect.so") && destchan->IsModeSet('L') && !destlimit.empty() && (destchan->GetUserCounter() >= atoi(destlimit.c_str())))
 303                                                 {
 304                                                         user->WriteNumeric(474, "%s %s :Cannot join channel (You are banned)", user->nick.c_str(), chan->name.c_str());
 305                                                         return 1;
 306                                                 }
 307                                                 else
 308                                                 {
 309                                                         user->WriteNumeric(474, "%s %s :Cannot join channel (You are banned)", user->nick.c_str(), chan->name.c_str());
 310                                                         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());
 311                                                         nofollow = true;
 312                                                         Channel::JoinUser(ServerInstance, user, redir->targetchan.c_str(), false, "", false, ServerInstance->Time());
 313                                                         nofollow = false;
 314                                                         return 1;
 315                                                 }
 316                                         }
 317                                 }
 318                         }
 319                 }
 320                 return 0;
 321         }
 322
 323         virtual ~ModuleBanRedirect()
 324         {
 325                 ServerInstance->Modes->DelModeWatcher(re);
 326                 delete re;
 327         }
 328
 329         virtual Version GetVersion()
 330         {
 331                 return Version("$Id$", VF_COMMON|VF_VENDOR, API_VERSION);
 332         }
 333
 334         void Prioritize()
 335         {
 336                 Module* banex = ServerInstance->Modules->Find("m_banexception.so");
 337                 ServerInstance->Modules->SetPriority(this, I_OnUserPreJoin, PRIORITY_BEFORE, &banex);
 338         }
 339 };
 340
 341 MODULE_INIT(ModuleBanRedirect)