src/modules/m_permchannels.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
  16 /* $ModDesc: Provides support for channel mode +P to provide permanent channels */
  17
  18 // Not in a class due to circular dependancy hell.
  19 static std::string permchannelsconf;
  20 static bool WriteDatabase()
  21 {
  22         FILE *f;
  23
  24         if (permchannelsconf.empty())
  25         {
  26                 // Fake success.
  27                 return true;
  28         }
  29
  30         std::string tempname = permchannelsconf + ".tmp";
  31
  32         /*
  33          * We need to perform an atomic write so as not to fuck things up.
  34          * So, let's write to a temporary file, flush and sync the FD, then rename the file..
  35          *              -- w00t
  36          */
  37         f = fopen(tempname.c_str(), "w");
  38         if (!f)
  39         {
  40                 ServerInstance->Logs->Log("m_permchannels",DEFAULT, "permchannels: Cannot create database! %s (%d)", strerror(errno), errno);
  41                 ServerInstance->SNO->WriteToSnoMask('a', "database: cannot create new db: %s (%d)", strerror(errno), errno);
  42                 return false;
  43         }
  44
  45         // Now, let's write.
  46         for (chan_hash::const_iterator i = ServerInstance->chanlist->begin(); i != ServerInstance->chanlist->end(); i++)
  47         {
  48                 Channel* chan = i->second;
  49                 if (!chan->IsModeSet('P'))
  50                         continue;
  51
  52                 char line[1024];
  53                 const char* items[] =
  54                 {
  55                         "<permchannels channel=",
  56                         chan->name.c_str(),
  57                         " topic=",
  58                         chan->topic.c_str(),
  59                         " modes=",
  60                         chan->ChanModes(true),
  61                         ">\n"
  62                 };
  63
  64                 int lpos = 0, item = 0, ipos = 0;
  65                 while (lpos < 1022 && item < 7)
  66                 {
  67                         char c = items[item][ipos++];
  68                         if (c == 0)
  69                         {
  70                                 // end of this string; hop to next string, insert a quote
  71                                 item++;
  72                                 ipos = 0;
  73                                 c = '"';
  74                         }
  75                         else if (c == '\\' || c == '"')
  76                         {
  77                                 line[lpos++] = '\\';
  78                         }
  79                         line[lpos++] = c;
  80                 }
  81                 line[--lpos] = 0;
  82                 fputs(line, f);
  83         }
  84
  85         int write_error = 0;
  86         write_error = ferror(f);
  87         write_error |= fclose(f);
  88         if (write_error)
  89         {
  90                 ServerInstance->Logs->Log("m_permchannels",DEFAULT, "permchannels: Cannot write to new database! %s (%d)", strerror(errno), errno);
  91                 ServerInstance->SNO->WriteToSnoMask('a', "database: cannot write to new db: %s (%d)", strerror(errno), errno);
  92                 return false;
  93         }
  94
  95         // Use rename to move temporary to new db - this is guarenteed not to fuck up, even in case of a crash.
  96         if (rename(tempname.c_str(), permchannelsconf.c_str()) < 0)
  97         {
  98                 ServerInstance->Logs->Log("m_permchannels",DEFAULT, "permchannels: Cannot move new to old database! %s (%d)", strerror(errno), errno);
  99                 ServerInstance->SNO->WriteToSnoMask('a', "database: cannot replace old with new db: %s (%d)", strerror(errno), errno);
 100                 return false;
 101         }
 102
 103         return true;
 104 }
 105
 106
 107
 108 /** Handles the +P channel mode
 109  */
 110 class PermChannel : public ModeHandler
 111 {
 112  public:
 113         PermChannel(Module* Creator) : ModeHandler(Creator, "permanent", 'P', PARAM_NONE, MODETYPE_CHANNEL) { oper = true; }
 114
 115         ModeAction OnModeChange(User* source, User* dest, Channel* channel, std::string &parameter, bool adding)
 116         {
 117                 if (adding)
 118                 {
 119                         if (!channel->IsModeSet('P'))
 120                         {
 121                                 channel->SetMode('P',true);
 122
 123                                 // Save permchannels db if needed.
 124                                 WriteDatabase();
 125                                 return MODEACTION_ALLOW;
 126                         }
 127                 }
 128                 else
 129                 {
 130                         if (channel->IsModeSet('P'))
 131                         {
 132                                 if (channel->GetUserCounter() == 0 && !IS_SERVER(source))
 133                                 {
 134                                         /*
 135                                          * ugh, ugh, UGH!
 136                                          *
 137                                          * We can't delete this channel the way things work at the moment,
 138                                          * because of the following scenario:
 139                                          * s1:#c <-> s2:#c
 140                                          *
 141                                          * s1 has a user in #c, s2 does not. s2 has +P set. s2 has a losing TS.
 142                                          *
 143                                          * On netmerge, s2 loses, so s2 removes all modes (including +P) which
 144                                          * would subsequently delete the channel here causing big fucking problems.
 145                                          *
 146                                          * I don't think there's really a way around this, so just deny -P on a 0 user chan.
 147                                          * -- w00t
 148                                          *
 149                                          * delete channel;
 150                                          */
 151                                         return MODEACTION_DENY;
 152                                 }
 153
 154                                 /* for servers, remove +P (to avoid desyncs) but don't bother trying to delete. */
 155                                 channel->SetMode('P',false);
 156
 157                                 // Save permchannels db if needed.
 158                                 WriteDatabase();
 159                                 return MODEACTION_ALLOW;
 160                         }
 161                 }
 162
 163                 return MODEACTION_DENY;
 164         }
 165 };
 166
 167 class ModulePermanentChannels : public Module
 168 {
 169         PermChannel p;
 170 public:
 171
 172         ModulePermanentChannels() : p(this)
 173         {
 174                 if (!ServerInstance->Modes->AddMode(&p))
 175                         throw ModuleException("Could not add new modes!");
 176                 Implementation eventlist[] = { I_OnChannelPreDelete, I_OnPostTopicChange, I_OnRawMode, I_OnRehash };
 177                 ServerInstance->Modules->Attach(eventlist, this, 4);
 178
 179                 OnRehash(NULL);
 180         }
 181
 182         CullResult cull()
 183         {
 184                 /*
 185                  * DelMode can't remove the +P mode on empty channels, or it will break
 186                  * merging modes with remote servers. Remove the empty channels now as
 187                  * we know this is not the case.
 188                  */
 189                 chan_hash::iterator iter = ServerInstance->chanlist->begin();
 190                 while (iter != ServerInstance->chanlist->end())
 191                 {
 192                         Channel* c = iter->second;
 193                         if (c->GetUserCounter() == 0)
 194                         {
 195                                 chan_hash::iterator at = iter;
 196                                 iter++;
 197                                 FOREACH_MOD(I_OnChannelDelete, OnChannelDelete(c));
 198                                 ServerInstance->chanlist->erase(at);
 199                                 ServerInstance->GlobalCulls.AddItem(c);
 200                         }
 201                         else
 202                                 iter++;
 203                 }
 204                 ServerInstance->Modes->DelMode(&p);
 205                 return Module::cull();
 206         }
 207
 208         virtual void OnRehash(User *user)
 209         {
 210                 /*
 211                  * Process config-defined list of permanent channels.
 212                  * -- w00t
 213                  */
 214
 215                 permchannelsconf = ServerInstance->Config->ConfValue("permchanneldb")->getString("filename");
 216
 217                 ConfigTagList permchannels = ServerInstance->Config->ConfTags("permchannels");
 218                 for (ConfigIter i = permchannels.first; i != permchannels.second; ++i)
 219                 {
 220                         ConfigTag* tag = i->second;
 221                         std::string channel = tag->getString("channel");
 222                         std::string topic = tag->getString("topic");
 223                         std::string modes = tag->getString("modes");
 224
 225                         if (channel.empty())
 226                         {
 227                                 ServerInstance->Logs->Log("blah", DEBUG, "Malformed permchannels tag with empty channel name.");
 228                                 continue;
 229                         }
 230
 231                         Channel *c = ServerInstance->FindChan(channel);
 232
 233                         if (!c)
 234                         {
 235                                 c = new Channel(channel, ServerInstance->Time());
 236                                 if (!topic.empty())
 237                                 {
 238                                         c->SetTopic(NULL, topic, true);
 239
 240                                         /*
 241                                          * Due to the way protocol works in 1.2, we need to hack the topic TS in such a way that this
 242                                          * topic will always win over others.
 243                                          *
 244                                          * This is scheduled for (proper) fixing in a later release, and can be removed at a later date.
 245                                          */
 246                                         c->topicset = 42;
 247                                 }
 248                                 ServerInstance->Logs->Log("blah", DEBUG, "Added %s with topic %s", channel.c_str(), topic.c_str());
 249
 250                                 if (modes.empty())
 251                                         continue;
 252
 253                                 irc::spacesepstream list(modes);
 254                                 std::string modeseq;
 255                                 std::string par;
 256
 257                                 list.GetToken(modeseq);
 258
 259                                 // XXX bleh, should we pass this to the mode parser instead? ugly. --w00t
 260                                 for (std::string::iterator n = modeseq.begin(); n != modeseq.end(); ++n)
 261                                 {
 262                                         ModeHandler* mode = ServerInstance->Modes->FindMode(*n, MODETYPE_CHANNEL);
 263                                         if (mode)
 264                                         {
 265                                                 if (mode->GetNumParams(true))
 266                                                         list.GetToken(par);
 267                                                 else
 268                                                         par.clear();
 269
 270                                                 mode->OnModeChange(ServerInstance->FakeClient, ServerInstance->FakeClient, c, par, true);
 271                                         }
 272                                 }
 273                         }
 274                 }
 275         }
 276
 277         virtual ModResult OnRawMode(User* user, Channel* chan, const char mode, const std::string &param, bool adding, int pcnt)
 278         {
 279                 if (chan && chan->IsModeSet('P'))
 280                         WriteDatabase();
 281
 282                 return MOD_RES_PASSTHRU;
 283         }
 284
 285         virtual void OnPostTopicChange(User*, Channel *c, const std::string&)
 286         {
 287                 if (c->IsModeSet('P'))
 288                         WriteDatabase();
 289         }
 290
 291         virtual Version GetVersion()
 292         {
 293                 return Version("Provides support for channel mode +P to provide permanent channels",VF_VENDOR);
 294         }
 295
 296         virtual ModResult OnChannelPreDelete(Channel *c)
 297         {
 298                 if (c->IsModeSet('P'))
 299                         return MOD_RES_DENY;
 300
 301                 return MOD_RES_PASSTHRU;
 302         }
 303 };
 304
 305 MODULE_INIT(ModulePermanentChannels)