src/modules/m_permchannels.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
  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, 'P', PARAM_NONE, MODETYPE_CHANNEL) { }
 114
 115         ModeAction OnModeChange(User* source, User* dest, Channel* channel, std::string &parameter, bool adding)
 116         {
 117                 if (!source->HasPrivPermission("channels/set-permanent"))
 118                 {
 119                         source->WriteNumeric(ERR_NOPRIVILEGES, "%s :Permission Denied - You do not have the required operator privileges", source->nick.c_str());
 120                         return MODEACTION_DENY;
 121                 }
 122
 123                 if (adding)
 124                 {
 125                         if (!channel->IsModeSet('P'))
 126                         {
 127                                 channel->SetMode('P',true);
 128
 129                                 // Save permchannels db if needed.
 130                                 WriteDatabase();
 131                                 return MODEACTION_ALLOW;
 132                         }
 133                 }
 134                 else
 135                 {
 136                         if (channel->IsModeSet('P'))
 137                         {
 138                                 if (channel->GetUserCounter() == 0 && !IS_FAKE(source))
 139                                 {
 140                                         /*
 141                                          * ugh, ugh, UGH!
 142                                          *
 143                                          * We can't delete this channel the way things work at the moment,
 144                                          * because of the following scenario:
 145                                          * s1:#c <-> s2:#c
 146                                          *
 147                                          * s1 has a user in #c, s2 does not. s2 has +P set. s2 has a losing TS.
 148                                          *
 149                                          * On netmerge, s2 loses, so s2 removes all modes (including +P) which
 150                                          * would subsequently delete the channel here causing big fucking problems.
 151                                          *
 152                                          * I don't think there's really a way around this, so just deny -P on a 0 user chan.
 153                                          * -- w00t
 154                                          *
 155                                          * delete channel;
 156                                          */
 157                                         return MODEACTION_DENY;
 158                                 }
 159
 160                                 /* for servers, remove +P (to avoid desyncs) but don't bother trying to delete. */
 161                                 channel->SetMode('P',false);
 162
 163                                 // Save permchannels db if needed.
 164                                 WriteDatabase();
 165                                 return MODEACTION_ALLOW;
 166                         }
 167                 }
 168
 169                 return MODEACTION_DENY;
 170         }
 171 };
 172
 173 class ModulePermanentChannels : public Module
 174 {
 175         PermChannel p;
 176 public:
 177
 178         ModulePermanentChannels() : p(this)
 179         {
 180                 if (!ServerInstance->Modes->AddMode(&p))
 181                         throw ModuleException("Could not add new modes!");
 182                 Implementation eventlist[] = { I_OnChannelPreDelete, I_OnPostTopicChange, I_OnRawMode };
 183                 ServerInstance->Modules->Attach(eventlist, this, 3);
 184
 185                 OnRehash(NULL);
 186         }
 187
 188         virtual ~ModulePermanentChannels()
 189         {
 190                 ServerInstance->Modes->DelMode(&p);
 191                 /*
 192                  * DelMode can't remove the +P mode on empty channels, or it will break
 193                  * merging modes with remote servers. Remove the empty channels now as
 194                  * we know this is not the case.
 195                  */
 196                 chan_hash::iterator iter = ServerInstance->chanlist->begin();
 197                 while (iter != ServerInstance->chanlist->end())
 198                 {
 199                         Channel* c = iter->second;
 200                         if (c->GetUserCounter() == 0)
 201                         {
 202                                 chan_hash::iterator at = iter;
 203                                 iter++;
 204                                 ServerInstance->chanlist->erase(at);
 205                                 delete c;
 206                         }
 207                         else
 208                                 iter++;
 209                 }
 210         }
 211
 212         virtual void OnRehash(User *user)
 213         {
 214                 /*
 215                  * Process config-defined list of permanent channels.
 216                  * -- w00t
 217                  */
 218                 ConfigReader MyConf;
 219
 220                 permchannelsconf = MyConf.ReadValue("permchanneldb", "filename", "", 0, false);
 221
 222                 for (int i = 0; i < MyConf.Enumerate("permchannels"); i++)
 223                 {
 224                         std::string channel = MyConf.ReadValue("permchannels", "channel", i);
 225                         std::string topic = MyConf.ReadValue("permchannels", "topic", i);
 226                         std::string modes = MyConf.ReadValue("permchannels", "modes", i);
 227
 228                         if (channel.empty())
 229                         {
 230                                 ServerInstance->Logs->Log("blah", DEBUG, "Malformed permchannels tag with empty channel name.");
 231                                 continue;
 232                         }
 233
 234                         Channel *c = ServerInstance->FindChan(channel);
 235
 236                         if (!c)
 237                         {
 238                                 c = new Channel(channel, ServerInstance->Time());
 239                                 if (!topic.empty())
 240                                 {
 241                                         c->SetTopic(NULL, topic, true);
 242
 243                                         /*
 244                                          * Due to the way protocol works in 1.2, we need to hack the topic TS in such a way that this
 245                                          * topic will always win over others.
 246                                          *
 247                                          * This is scheduled for (proper) fixing in a later release, and can be removed at a later date.
 248                                          */
 249                                         c->topicset = 42;
 250                                 }
 251                                 ServerInstance->Logs->Log("blah", DEBUG, "Added %s with topic %s", channel.c_str(), topic.c_str());
 252
 253                                 if (modes.empty())
 254                                         continue;
 255
 256                                 irc::spacesepstream list(modes);
 257                                 std::string modeseq;
 258                                 std::string par;
 259
 260                                 list.GetToken(modeseq);
 261
 262                                 // XXX bleh, should we pass this to the mode parser instead? ugly. --w00t
 263                                 for (std::string::iterator n = modeseq.begin(); n != modeseq.end(); ++n)
 264                                 {
 265                                         ModeHandler* mode = ServerInstance->Modes->FindMode(*n, MODETYPE_CHANNEL);
 266                                         if (mode)
 267                                         {
 268                                                 if (mode->GetNumParams(true))
 269                                                         list.GetToken(par);
 270                                                 else
 271                                                         par.clear();
 272
 273                                                 mode->OnModeChange(ServerInstance->FakeClient, ServerInstance->FakeClient, c, par, true);
 274                                         }
 275                                 }
 276                         }
 277                 }
 278         }
 279
 280         virtual ModResult OnRawMode(User* user, Channel* chan, const char mode, const std::string &param, bool adding, int pcnt)
 281         {
 282                 if (chan && chan->IsModeSet('P'))
 283                         WriteDatabase();
 284
 285                 return MOD_RES_PASSTHRU;
 286         }
 287
 288         virtual void OnPostTopicChange(User*, Channel *c, const std::string&)
 289         {
 290                 if (c->IsModeSet('P'))
 291                         WriteDatabase();
 292         }
 293
 294         virtual Version GetVersion()
 295         {
 296                 return Version("Provides support for channel mode +P to provide permanent channels",VF_COMMON|VF_VENDOR,API_VERSION);
 297         }
 298
 299         virtual ModResult OnChannelPreDelete(Channel *c)
 300         {
 301                 if (c->IsModeSet('P'))
 302                         return MOD_RES_DENY;
 303
 304                 return MOD_RES_PASSTHRU;
 305         }
 306 };
 307
 308 MODULE_INIT(ModulePermanentChannels)