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