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m_banredirect.cpp

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00001 /*       +------------------------------------+
00002  *       | Inspire Internet Relay Chat Daemon |
00003  *       +------------------------------------+
00004  *
00005  *  InspIRCd: (C) 2002-2008 InspIRCd Development Team
00006  * See: http://www.inspircd.org/wiki/index.php/Credits
00007  *
00008  * This program is free but copyrighted software; see
00009  *            the file COPYING for details.
00010  *
00011  * ---------------------------------------------------
00012  */
00013 
00014 #include "inspircd.h"
00015 #include "u_listmode.h"
00016 
00017 /* $ModDesc: Allows an extended ban (+b) syntax redirecting banned users to another channel */
00018 /* $ModDep: ../../include/u_listmode.h */
00019 
00020 /* Originally written by Om, January 2008
00021  */
00022 
00023 class BanRedirectEntry : public classbase
00024 {
00025  public:
00026         std::string targetchan;
00027         std::string banmask;
00028 
00029         BanRedirectEntry(const std::string &target = "", const std::string &mask = "")
00030         : targetchan(target), banmask(mask)
00031         {
00032         }
00033 };
00034 
00035 typedef std::vector<BanRedirectEntry> BanRedirectList;
00036 typedef std::deque<std::string> StringDeque;
00037 
00038 class BanRedirect : public ModeWatcher
00039 {
00040  private:
00041         InspIRCd* Srv;
00042  public:
00043         BanRedirect(InspIRCd* Instance)
00044         : ModeWatcher(Instance, 'b', MODETYPE_CHANNEL), Srv(Instance)
00045         {
00046         }
00047 
00048         bool BeforeMode(User* source, User* dest, Channel* channel, std::string &param, bool adding, ModeType type, bool)
00049         {
00050                 /* nick!ident@host -> nick!ident@host
00051                  * nick!ident@host#chan -> nick!ident@host#chan
00052                  * nick@host#chan -> nick!*@host#chan
00053                  * nick!ident#chan -> nick!ident@*#chan
00054                  * nick#chan -> nick!*@*#chan
00055                  */
00056 
00057                 if(channel && (type == MODETYPE_CHANNEL) && param.length())
00058                 {
00059                         BanRedirectList* redirects;
00060 
00061                         std::string mask[4];
00062                         enum { NICK, IDENT, HOST, CHAN } current = NICK;
00063                         std::string::iterator start_pos = param.begin();
00064                         long maxbans = channel->GetMaxBans();
00065 
00066                         if (param.length() >= 2 && param[1] == ':')
00067                                 return true;
00068 
00069                         if(adding && (channel->bans.size() > static_cast<unsigned>(maxbans)))
00070                         {
00071                                 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);
00072                                 return false;
00073                         }
00074 
00075                         for(std::string::iterator curr = start_pos; curr != param.end(); curr++)
00076                         {
00077                                 switch(*curr)
00078                                 {
00079                                         case '!':
00080                                                 mask[current].assign(start_pos, curr);
00081                                                 current = IDENT;
00082                                                 start_pos = curr+1;
00083                                                 break;
00084                                         case '@':
00085                                                 mask[current].assign(start_pos, curr);
00086                                                 current = HOST;
00087                                                 start_pos = curr+1;
00088                                                 break;
00089                                         case '#':
00090                                                 mask[current].assign(start_pos, curr);
00091                                                 current = CHAN;
00092                                                 start_pos = curr;
00093                                                 break;
00094                                 }
00095                         }
00096 
00097                         if(mask[current].empty())
00098                         {
00099                                 mask[current].assign(start_pos, param.end());
00100                         }
00101 
00102                         /* nick@host wants to be changed to *!nick@host rather than nick!*@host... */
00103                         if(mask[NICK].length() && mask[HOST].length() && mask[IDENT].empty())
00104                         {
00105                                 /* std::string::swap() is fast - it runs in constant time */
00106                                 mask[NICK].swap(mask[IDENT]);
00107                         }
00108 
00109                         for(int i = 0; i < 3; i++)
00110                         {
00111                                 if(mask[i].empty())
00112                                 {
00113                                         mask[i].assign("*");
00114                                 }
00115                         }
00116 
00117                         param.assign(mask[NICK]).append(1, '!').append(mask[IDENT]).append(1, '@').append(mask[HOST]);
00118 
00119                         if(mask[CHAN].length())
00120                         {
00121                                 if(!IS_LOCAL(source) || Srv->IsChannel(mask[CHAN].c_str(), ServerInstance->Config->Limits.ChanMax))
00122                                 {
00123                                         if (assign(channel->name) == mask[CHAN])
00124                                         {
00125                                                 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());
00126                                                 return false;
00127                                         }
00128                                         else
00129                                         {
00130                                                 if(adding)
00131                                                 {
00132                                                         /* It's a properly valid redirecting ban, and we're adding it */
00133                                                         if(!channel->GetExt("banredirects", redirects))
00134                                                         {
00135                                                                 redirects = new BanRedirectList;
00136                                                                 channel->Extend("banredirects", redirects);
00137                                                         }
00138 
00139                                                         /* Here 'param' doesn't have the channel on it yet */
00140                                                         redirects->push_back(BanRedirectEntry(mask[CHAN].c_str(), param.c_str()));
00141 
00142                                                         /* Now it does */
00143                                                         param.append(mask[CHAN]);
00144                                                 }
00145                                                 else
00146                                                 {
00147                                                         /* Removing a ban, if there's no extensible there are no redirecting bans and we're fine. */
00148                                                         if(channel->GetExt("banredirects", redirects))
00149                                                         {
00150                                                                 /* But there were, so we need to remove the matching one if there is one */
00151 
00152                                                                 for(BanRedirectList::iterator redir = redirects->begin(); redir != redirects->end(); redir++)
00153                                                                 {
00154                                                                         /* Ugly as fuck */
00155                                                                         if((irc::string(redir->targetchan.c_str()) == irc::string(mask[CHAN].c_str())) && (irc::string(redir->banmask.c_str()) == irc::string(param.c_str())))
00156                                                                         {
00157                                                                                 redirects->erase(redir);
00158 
00159                                                                                 if(redirects->empty())
00160                                                                                 {
00161                                                                                         delete redirects;
00162                                                                                         channel->Shrink("banredirects");
00163                                                                                 }
00164 
00165                                                                                 break;
00166                                                                         }
00167                                                                 }
00168                                                         }
00169 
00170                                                         /* Append the channel so the default +b handler can remove the entry too */
00171                                                         param.append(mask[CHAN]);
00172                                                 }
00173                                         }
00174                                 }
00175                                 else
00176                                 {
00177                                         source->WriteNumeric(403, "%s %s :Invalid channel name in redirection (%s)", source->nick.c_str(), channel->name.c_str(), mask[CHAN].c_str());
00178                                         return false;
00179                                 }
00180                         }
00181                 }
00182 
00183                 return true;
00184         }
00185 };
00186 
00187 class ModuleBanRedirect : public Module
00188 {
00189         BanRedirect* re;
00190         bool nofollow;
00191         Module* ExceptionModule;
00192 
00193  public:
00194         ModuleBanRedirect(InspIRCd* Me)
00195         : Module(Me)
00196         {
00197                 re = new BanRedirect(Me);
00198                 nofollow = false;
00199 
00200                 if(!ServerInstance->Modes->AddModeWatcher(re))
00201                 {
00202                         delete re;
00203                         throw ModuleException("Could not add mode watcher");
00204                 }
00205 
00206                 OnRehash(NULL, "");
00207 
00208                 Implementation list[] = { I_OnRehash, I_OnUserPreJoin, I_OnChannelDelete, I_OnCleanup };
00209                 Me->Modules->Attach(list, this, 4);
00210 
00211         }
00212 
00213         virtual void OnChannelDelete(Channel* chan)
00214         {
00215                 OnCleanup(TYPE_CHANNEL, chan);
00216         }
00217 
00218         virtual void OnCleanup(int target_type, void* item)
00219         {
00220                 if(target_type == TYPE_CHANNEL)
00221                 {
00222                         Channel* chan = static_cast<Channel*>(item);
00223                         BanRedirectList* redirects;
00224 
00225                         if(chan->GetExt("banredirects", redirects))
00226                         {
00227                                 irc::modestacker modestack(ServerInstance, false);
00228                                 StringDeque stackresult;
00229                                 std::vector<std::string> mode_junk;
00230                                 mode_junk.push_back(chan->name);
00231 
00232                                 for(BanRedirectList::iterator i = redirects->begin(); i != redirects->end(); i++)
00233                                 {
00234                                         modestack.Push('b', i->targetchan.insert(0, i->banmask));
00235                                 }
00236 
00237                                 for(BanRedirectList::iterator i = redirects->begin(); i != redirects->end(); i++)
00238                                 {
00239                                         modestack.PushPlus();
00240                                         modestack.Push('b', i->banmask);
00241                                 }
00242 
00243                                 while(modestack.GetStackedLine(stackresult))
00244                                 {
00245                                         for(StringDeque::size_type i = 0; i < stackresult.size(); i++)
00246                                         {
00247                                                 mode_junk.push_back(stackresult[i]);
00248                                         }
00249 
00250                                         ServerInstance->SendMode(mode_junk, ServerInstance->FakeClient);
00251                                 }
00252 
00253                                 delete redirects;
00254                                 chan->Shrink("banredirects");
00255                         }
00256                 }
00257         }
00258 
00259         virtual void OnRehash(User* user, const std::string &param)
00260         {
00261                 ExceptionModule = ServerInstance->Modules->Find("m_banexception.so");
00262         }
00263 
00264         virtual int OnUserPreJoin(User* user, Channel* chan, const char* cname, std::string &privs, const std::string &keygiven)
00265         {
00266                 /* This prevents recursion when a user sets multiple ban redirects in a chain
00267                  * (thanks Potter)
00268                  */
00269                 if (nofollow)
00270                         return 0;
00271 
00272                 /* Return 1 to prevent the join, 0 to allow it */
00273                 if (chan)
00274                 {
00275                         BanRedirectList* redirects;
00276 
00277                         if(chan->GetExt("banredirects", redirects))
00278                         {
00279                                 /* We actually had some ban redirects to check */
00280 
00281                                 /* This was replaced with user->MakeHostIP() when I had a snprintf(), but MakeHostIP() doesn't seem to add the nick.
00282                                  * Maybe we should have a GetFullIPHost() or something to match GetFullHost() and GetFullRealHost?
00283                                  */
00284 
00285                                 if (ExceptionModule)
00286                                 {
00287                                         ListModeRequest n(this, ExceptionModule, user, chan);
00288                                         /* Users with ban exceptions are allowed to join without being redirected */
00289                                         if (n.Send())
00290                                                 return 0;
00291                                 }
00292 
00293                                 std::string ipmask(user->nick);
00294                                 ipmask.append(1, '!').append(user->MakeHostIP());
00295 
00296                                 for(BanRedirectList::iterator redir = redirects->begin(); redir != redirects->end(); redir++)
00297                                 {
00298                                         if(InspIRCd::Match(user->GetFullRealHost(), redir->banmask) || InspIRCd::Match(user->GetFullHost(), redir->banmask) || InspIRCd::MatchCIDR(ipmask, redir->banmask))
00299                                         {
00300                                                 /* tell them they're banned and are being transferred */
00301                                                 Channel* destchan = ServerInstance->FindChan(redir->targetchan);
00302                                                 std::string destlimit;
00303 
00304                                                 if (destchan)
00305                                                         destlimit = destchan->GetModeParameter('l');
00306 
00307                                                 if(destchan && ServerInstance->Modules->Find("m_redirect.so") && destchan->IsModeSet('L') && !destlimit.empty() && (destchan->GetUserCounter() >= atoi(destlimit.c_str())))
00308                                                 {
00309                                                         user->WriteNumeric(474, "%s %s :Cannot join channel (You are banned)", user->nick.c_str(), chan->name.c_str());
00310                                                         return 1;
00311                                                 }
00312                                                 else
00313                                                 {
00314                                                         user->WriteNumeric(474, "%s %s :Cannot join channel (You are banned)", user->nick.c_str(), chan->name.c_str());
00315                                                         user->WriteNumeric(470, "%s :You are being automatically redirected to %s", user->nick.c_str(), redir->targetchan.c_str());
00316                                                         nofollow = true;
00317                                                         Channel::JoinUser(ServerInstance, user, redir->targetchan.c_str(), false, "", false, ServerInstance->Time());
00318                                                         nofollow = false;
00319                                                         return 1;
00320                                                 }
00321                                         }
00322                                 }
00323                         }
00324                 }
00325                 return 0;
00326         }
00327 
00328         virtual ~ModuleBanRedirect()
00329         {
00330                 ServerInstance->Modes->DelModeWatcher(re);
00331                 delete re;
00332         }
00333 
00334         virtual Version GetVersion()
00335         {
00336                 return Version("$Id: m_banredirect.cpp 10415 2008-09-06 13:36:09Z brain $", VF_COMMON | VF_VENDOR, API_VERSION);
00337         }
00338 
00339         void Prioritize()
00340         {
00341                 Module* banex = ServerInstance->Modules->Find("m_banexception.so");
00342                 ServerInstance->Modules->SetPriority(this, I_OnUserPreJoin, PRIO_BEFORE, &banex);
00343         }
00344 };
00345 
00346 MODULE_INIT(ModuleBanRedirect)