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                                 return MODEACTION_ALLOW;
 123                         }
 124                 }
 125                 else
 126                 {
 127                         if (channel->IsModeSet('P'))
 128                         {
 129                                 if (channel->GetUserCounter() == 0 && !IS_SERVER(source))
 130                                 {
 131                                         /*
 132                                          * ugh, ugh, UGH!
 133                                          *
 134                                          * We can't delete this channel the way things work at the moment,
 135                                          * because of the following scenario:
 136                                          * s1:#c <-> s2:#c
 137                                          *
 138                                          * s1 has a user in #c, s2 does not. s2 has +P set. s2 has a losing TS.
 139                                          *
 140                                          * On netmerge, s2 loses, so s2 removes all modes (including +P) which
 141                                          * would subsequently delete the channel here causing big fucking problems.
 142                                          *
 143                                          * I don't think there's really a way around this, so just deny -P on a 0 user chan.
 144                                          * -- w00t
 145                                          *
 146                                          * delete channel;
 147                                          */
 148                                         return MODEACTION_DENY;
 149                                 }
 150
 151                                 /* for servers, remove +P (to avoid desyncs) but don't bother trying to delete. */
 152                                 channel->SetMode('P',false);
 153                                 return MODEACTION_ALLOW;
 154                         }
 155                 }
 156
 157                 return MODEACTION_DENY;
 158         }
 159 };
 160
 161 class ModulePermanentChannels : public Module
 162 {
 163         PermChannel p;
 164         bool dirty;
 165 public:
 166
 167         ModulePermanentChannels() : p(this), dirty(false)
 168         {
 169         }
 170
 171         void init()
 172         {
 173                 ServerInstance->Modes->AddService(p);
 174                 Implementation eventlist[] = { I_OnChannelPreDelete, I_OnPostTopicChange, I_OnRawMode, I_OnRehash, I_OnBackgroundTimer };
 175                 ServerInstance->Modules->Attach(eventlist, this, 5);
 176
 177                 OnRehash(NULL);
 178         }
 179
 180         CullResult cull()
 181         {
 182                 /*
 183                  * DelMode can't remove the +P mode on empty channels, or it will break
 184                  * merging modes with remote servers. Remove the empty channels now as
 185                  * we know this is not the case.
 186                  */
 187                 chan_hash::iterator iter = ServerInstance->chanlist->begin();
 188                 while (iter != ServerInstance->chanlist->end())
 189                 {
 190                         Channel* c = iter->second;
 191                         if (c->GetUserCounter() == 0)
 192                         {
 193                                 chan_hash::iterator at = iter;
 194                                 iter++;
 195                                 FOREACH_MOD(I_OnChannelDelete, OnChannelDelete(c));
 196                                 ServerInstance->chanlist->erase(at);
 197                                 ServerInstance->GlobalCulls.AddItem(c);
 198                         }
 199                         else
 200                                 iter++;
 201                 }
 202                 ServerInstance->Modes->DelMode(&p);
 203                 return Module::cull();
 204         }
 205
 206         virtual void OnRehash(User *user)
 207         {
 208                 /*
 209                  * Process config-defined list of permanent channels.
 210                  * -- w00t
 211                  */
 212
 213                 permchannelsconf = ServerInstance->Config->ConfValue("permchanneldb")->getString("filename");
 214
 215                 ConfigTagList permchannels = ServerInstance->Config->ConfTags("permchannels");
 216                 for (ConfigIter i = permchannels.first; i != permchannels.second; ++i)
 217                 {
 218                         ConfigTag* tag = i->second;
 219                         std::string channel = tag->getString("channel");
 220                         std::string topic = tag->getString("topic");
 221                         std::string modes = tag->getString("modes");
 222
 223                         if (channel.empty())
 224                         {
 225                                 ServerInstance->Logs->Log("blah", DEBUG, "Malformed permchannels tag with empty channel name.");
 226                                 continue;
 227                         }
 228
 229                         Channel *c = ServerInstance->FindChan(channel);
 230
 231                         if (!c)
 232                         {
 233                                 c = new Channel(channel, ServerInstance->Time());
 234                                 if (!topic.empty())
 235                                 {
 236                                         c->SetTopic(NULL, topic, true);
 237
 238                                         /*
 239                                          * Due to the way protocol works in 1.2, we need to hack the topic TS in such a way that this
 240                                          * topic will always win over others.
 241                                          *
 242                                          * This is scheduled for (proper) fixing in a later release, and can be removed at a later date.
 243                                          */
 244                                         c->topicset = 42;
 245                                 }
 246                                 ServerInstance->Logs->Log("blah", DEBUG, "Added %s with topic %s", channel.c_str(), topic.c_str());
 247
 248                                 if (modes.empty())
 249                                         continue;
 250
 251                                 irc::spacesepstream list(modes);
 252                                 std::string modeseq;
 253                                 std::string par;
 254
 255                                 list.GetToken(modeseq);
 256
 257                                 // XXX bleh, should we pass this to the mode parser instead? ugly. --w00t
 258                                 for (std::string::iterator n = modeseq.begin(); n != modeseq.end(); ++n)
 259                                 {
 260                                         ModeHandler* mode = ServerInstance->Modes->FindMode(*n, MODETYPE_CHANNEL);
 261                                         if (mode)
 262                                         {
 263                                                 if (mode->GetNumParams(true))
 264                                                         list.GetToken(par);
 265                                                 else
 266                                                         par.clear();
 267
 268                                                 mode->OnModeChange(ServerInstance->FakeClient, ServerInstance->FakeClient, c, par, true);
 269                                         }
 270                                 }
 271                         }
 272                 }
 273         }
 274
 275         virtual ModResult OnRawMode(User* user, Channel* chan, const char mode, const std::string &param, bool adding, int pcnt)
 276         {
 277                 if (chan && (chan->IsModeSet('P') || mode == 'P'))
 278                         dirty = true;
 279
 280                 return MOD_RES_PASSTHRU;
 281         }
 282
 283         virtual void OnPostTopicChange(User*, Channel *c, const std::string&)
 284         {
 285                 if (c->IsModeSet('P'))
 286                         dirty = true;
 287         }
 288
 289         void OnBackgroundTimer(time_t)
 290         {
 291                 if (dirty)
 292                         WriteDatabase();
 293                 dirty = false;
 294         }
 295
 296         virtual Version GetVersion()
 297         {
 298                 return Version("Provides support for channel mode +P to provide permanent channels",VF_VENDOR);
 299         }
 300
 301         virtual ModResult OnChannelPreDelete(Channel *c)
 302         {
 303                 if (c->IsModeSet('P'))
 304                         return MOD_RES_DENY;
 305
 306                 return MOD_RES_PASSTHRU;
 307         }
 308 };
 309
 310 MODULE_INIT(ModulePermanentChannels)