src/modules/m_banredirect.cpp

   1 /*       +------------------------------------+
   2  *       | Inspire Internet Relay Chat Daemon |
   3  *       +------------------------------------+
   4  *
   5  *  InspIRCd: (C) 2002-2010 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
  19 /* Originally written by Om, January 2009
  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  public:
  40         SimpleExtItem<BanRedirectList> extItem;
  41         BanRedirect(Module* parent) : ModeWatcher(parent, 'b', MODETYPE_CHANNEL),
  42                 extItem("banredirect", parent)
  43         {
  44         }
  45
  46         bool BeforeMode(User* source, User* dest, Channel* channel, std::string &param, bool adding, ModeType type)
  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                                                 /* bug #921: don't barf when redirecting to ## channels */
  89                                                 if (current != CHAN)
  90                                                 {
  91                                                         mask[current].assign(start_pos, curr);
  92                                                         current = CHAN;
  93                                                         start_pos = curr;
  94                                                 }
  95                                                 break;
  96                                 }
  97                         }
  98
  99                         if(mask[current].empty())
 100                         {
 101                                 mask[current].assign(start_pos, param.end());
 102                         }
 103
 104                         /* nick@host wants to be changed to *!nick@host rather than nick!*@host... */
 105                         if(mask[NICK].length() && mask[HOST].length() && mask[IDENT].empty())
 106                         {
 107                                 /* std::string::swap() is fast - it runs in constant time */
 108                                 mask[NICK].swap(mask[IDENT]);
 109                         }
 110
 111                         for(int i = 0; i < 3; i++)
 112                         {
 113                                 if(mask[i].empty())
 114                                 {
 115                                         mask[i].assign("*");
 116                                 }
 117                         }
 118
 119                         param.assign(mask[NICK]).append(1, '!').append(mask[IDENT]).append(1, '@').append(mask[HOST]);
 120
 121                         if(mask[CHAN].length())
 122                         {
 123                                 if (adding && IS_LOCAL(source))
 124                                 {
 125                                         if (!ServerInstance->IsChannel(mask[CHAN].c_str(),  ServerInstance->Config->Limits.ChanMax))
 126                                         {
 127                                                 source->WriteNumeric(403, "%s %s :Invalid channel name in redirection (%s)", source->nick.c_str(), channel->name.c_str(), mask[CHAN].c_str());
 128                                                 return false;
 129                                         }
 130
 131                                         Channel *c = ServerInstance->FindChan(mask[CHAN].c_str());
 132                                         if (!c)
 133                                         {
 134                                                 source->WriteNumeric(690, "%s :Target channel %s must exist to be set as a redirect.",source->nick.c_str(),mask[CHAN].c_str());
 135                                                 return false;
 136                                         }
 137                                         else if (adding && c->GetPrefixValue(source) < OP_VALUE)
 138                                         {
 139                                                 source->WriteNumeric(690, "%s :You must be opped on %s to set it as a redirect.",source->nick.c_str(), mask[CHAN].c_str());
 140                                                 return false;
 141                                         }
 142
 143                                         if (assign(channel->name) == mask[CHAN])
 144                                         {
 145                                                 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());
 146                                                 return false;
 147                                         }
 148                                 }
 149
 150                                 if(adding)
 151                                 {
 152                                         /* It's a properly valid redirecting ban, and we're adding it */
 153                                         redirects = extItem.get(channel);
 154                                         if (!redirects)
 155                                         {
 156                                                 redirects = new BanRedirectList;
 157                                                 extItem.set(channel, redirects);
 158                                         }
 159
 160                                         /* Here 'param' doesn't have the channel on it yet */
 161                                         redirects->push_back(BanRedirectEntry(mask[CHAN].c_str(), param.c_str()));
 162
 163                                         /* Now it does */
 164                                         param.append(mask[CHAN]);
 165                                 }
 166                                 else
 167                                 {
 168                                         /* Removing a ban, if there's no extensible there are no redirecting bans and we're fine. */
 169                                         redirects = extItem.get(channel);
 170                                         if (redirects)
 171                                         {
 172                                                 /* But there were, so we need to remove the matching one if there is one */
 173
 174                                                 for(BanRedirectList::iterator redir = redirects->begin(); redir != redirects->end(); redir++)
 175                                                 {
 176                                                         /* Ugly as fuck */
 177                                                         if((irc::string(redir->targetchan.c_str()) == irc::string(mask[CHAN].c_str())) && (irc::string(redir->banmask.c_str()) == irc::string(param.c_str())))
 178                                                         {
 179                                                                 redirects->erase(redir);
 180
 181                                                                 if(redirects->empty())
 182                                                                 {
 183                                                                         extItem.unset(channel);
 184                                                                 }
 185
 186                                                                 break;
 187                                                         }
 188                                                 }
 189                                         }
 190
 191                                         /* Append the channel so the default +b handler can remove the entry too */
 192                                         param.append(mask[CHAN]);
 193                                 }
 194                         }
 195                 }
 196
 197                 return true;
 198         }
 199 };
 200
 201 class ModuleBanRedirect : public Module
 202 {
 203         BanRedirect re;
 204         bool nofollow;
 205
 206  public:
 207         ModuleBanRedirect()
 208         : re(this)
 209         {
 210                 nofollow = false;
 211         }
 212
 213
 214         void init()
 215         {
 216                 if(!ServerInstance->Modes->AddModeWatcher(&re))
 217                         throw ModuleException("Could not add mode watcher");
 218
 219                 OnRehash(NULL);
 220
 221                 ServerInstance->Extensions.Register(&re.extItem);
 222                 Implementation list[] = { I_OnRehash, I_OnUserPreJoin, I_OnChannelDelete };
 223                 ServerInstance->Modules->Attach(list, this, 3);
 224         }
 225
 226         virtual void OnChannelDelete(Channel* chan)
 227         {
 228                 OnCleanup(TYPE_CHANNEL, chan);
 229         }
 230
 231         virtual void OnCleanup(int target_type, void* item)
 232         {
 233                 if(target_type == TYPE_CHANNEL)
 234                 {
 235                         Channel* chan = static_cast<Channel*>(item);
 236                         BanRedirectList* redirects = re.extItem.get(chan);
 237
 238                         if(redirects)
 239                         {
 240                                 irc::modestacker modestack(false);
 241                                 StringDeque stackresult;
 242                                 std::vector<std::string> mode_junk;
 243                                 mode_junk.push_back(chan->name);
 244
 245                                 for(BanRedirectList::iterator i = redirects->begin(); i != redirects->end(); i++)
 246                                 {
 247                                         modestack.Push('b', i->targetchan.insert(0, i->banmask));
 248                                 }
 249
 250                                 for(BanRedirectList::iterator i = redirects->begin(); i != redirects->end(); i++)
 251                                 {
 252                                         modestack.PushPlus();
 253                                         modestack.Push('b', i->banmask);
 254                                 }
 255
 256                                 while(modestack.GetStackedLine(stackresult))
 257                                 {
 258                                         mode_junk.insert(mode_junk.end(), stackresult.begin(), stackresult.end());
 259                                         ServerInstance->SendMode(mode_junk, ServerInstance->FakeClient);
 260                                         mode_junk.erase(mode_junk.begin() + 1, mode_junk.end());
 261                                 }
 262                         }
 263                 }
 264         }
 265
 266         virtual void OnRehash(User* user)
 267         {
 268         }
 269
 270         virtual ModResult OnUserPreJoin(User* user, Channel* chan, const char* cname, std::string &privs, const std::string &keygiven)
 271         {
 272                 /* This prevents recursion when a user sets multiple ban redirects in a chain
 273                  * (thanks Potter)
 274                  */
 275                 if (nofollow)
 276                         return MOD_RES_PASSTHRU;
 277
 278                 /* Return 1 to prevent the join, 0 to allow it */
 279                 if (chan)
 280                 {
 281                         BanRedirectList* redirects = re.extItem.get(chan);
 282
 283                         if (redirects)
 284                         {
 285                                 /* We actually had some ban redirects to check */
 286
 287                                 /* This was replaced with user->MakeHostIP() when I had a snprintf(), but MakeHostIP() doesn't seem to add the nick.
 288                                  * Maybe we should have a GetFullIPHost() or something to match GetFullHost() and GetFullRealHost?
 289                                  */
 290
 291                                 ModResult result;
 292                                 FIRST_MOD_RESULT(OnCheckChannelBan, result, (user, chan));
 293                                 if (result == MOD_RES_ALLOW)
 294                                 {
 295                                         // they have a ban exception
 296                                         return MOD_RES_PASSTHRU;
 297                                 }
 298
 299                                 std::string ipmask(user->nick);
 300                                 ipmask.append(1, '!').append(user->MakeHostIP());
 301
 302                                 for(BanRedirectList::iterator redir = redirects->begin(); redir != redirects->end(); redir++)
 303                                 {
 304                                         if(InspIRCd::Match(user->GetFullRealHost(), redir->banmask) || InspIRCd::Match(user->GetFullHost(), redir->banmask) || InspIRCd::MatchCIDR(ipmask, redir->banmask))
 305                                         {
 306                                                 /* tell them they're banned and are being transferred */
 307                                                 Channel* destchan = ServerInstance->FindChan(redir->targetchan);
 308                                                 std::string destlimit;
 309
 310                                                 if (destchan)
 311                                                         destlimit = destchan->GetModeParameter('l');
 312
 313                                                 if(destchan && ServerInstance->Modules->Find("m_redirect.so") && destchan->IsModeSet('L') && !destlimit.empty() && (destchan->GetUserCounter() >= atoi(destlimit.c_str())))
 314                                                 {
 315                                                         user->WriteNumeric(474, "%s %s :Cannot join channel (You are banned)", user->nick.c_str(), chan->name.c_str());
 316                                                         return MOD_RES_DENY;
 317                                                 }
 318                                                 else
 319                                                 {
 320                                                         user->WriteNumeric(474, "%s %s :Cannot join channel (You are banned)", user->nick.c_str(), chan->name.c_str());
 321                                                         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());
 322                                                         nofollow = true;
 323                                                         Channel::JoinUser(user, redir->targetchan.c_str(), false, "", false, ServerInstance->Time());
 324                                                         nofollow = false;
 325                                                         return MOD_RES_DENY;
 326                                                 }
 327                                         }
 328                                 }
 329                         }
 330                 }
 331                 return MOD_RES_PASSTHRU;
 332         }
 333
 334         virtual ~ModuleBanRedirect()
 335         {
 336                 /* XXX is this the best place to do this? */
 337                 if (!ServerInstance->Modes->DelModeWatcher(&re))
 338                         ServerInstance->Logs->Log("m_banredirect.so", DEBUG, "Failed to delete modewatcher!");
 339         }
 340
 341         virtual Version GetVersion()
 342         {
 343                 return Version("Allows an extended ban (+b) syntax redirecting banned users to another channel", VF_COMMON|VF_VENDOR);
 344         }
 345
 346         void Prioritize()
 347         {
 348                 Module* banex = ServerInstance->Modules->Find("m_banexception.so");
 349                 ServerInstance->Modules->SetPriority(this, I_OnUserPreJoin, PRIORITY_BEFORE, &banex);
 350         }
 351 };
 352
 353 MODULE_INIT(ModuleBanRedirect)