/** FJOIN, almost identical to TS6 SJOIN, except for nicklist handling. */ CmdResult CommandFJoin::Handle(const std::vector<std::string>& params, User *srcuser) { SpanningTreeUtilities* Utils = ((ModuleSpanningTree*)(Module*)creator)->Utils; /* 1.1+ FJOIN works as follows: * * Each FJOIN is sent along with a timestamp, and the side with the lowest * timestamp 'wins'. From this point on we will refer to this side as the * winner. The side with the higher timestamp loses, from this point on we * will call this side the loser or losing side. This should be familiar to * anyone who's dealt with dreamforge or TS6 before. * * When two sides of a split heal and this occurs, the following things * will happen: * * If the timestamps are exactly equal, both sides merge their privilages * and users, as in InspIRCd 1.0 and ircd2.8. The channels have not been * re-created during a split, this is safe to do. * * If the timestamps are NOT equal, the losing side removes all of its * modes from the channel, before introducing new users into the channel * which are listed in the FJOIN command's parameters. The losing side then * LOWERS its timestamp value of the channel to match that of the winning * side, and the modes of the users of the winning side are merged in with * the losing side. * * The winning side on the other hand will ignore all user modes from the * losing side, so only its own modes get applied. Life is simple for those * who succeed at internets. :-) * * Syntax: * :<sid> FJOIN <chan> <TS> <modes> :[[modes,]<uuid> [[modes,]<uuid> ... ]] * The last parameter is a list consisting of zero or more (modelist, uuid) * pairs (permanent channels may have zero users). The mode list for each * user is a concatenation of the mode letters the user has on the channel * (e.g.: "ov" if the user is opped and voiced). The order of the mode letters * are not important but if a server ecounters an unknown mode letter, it will * drop the link to avoid desync. * * InspIRCd 2.0 and older required a comma before the uuid even if the user * had no prefix modes on the channel, InspIRCd 2.2 and later does not require * a comma in this case anymore. * */ time_t TS = ConvToInt(params[1]); if (!TS) { ServerInstance->Logs->Log("m_spanningtree",LOG_DEFAULT,"*** BUG? *** TS of 0 sent to FJOIN. Are some services authors smoking craq, or is it 1970 again?. Dropped."); ServerInstance->SNO->WriteToSnoMask('d', "WARNING: The server %s is sending FJOIN with a TS of zero. Total craq. Command was dropped.", srcuser->server.c_str()); return CMD_INVALID; } const std::string& channel = params[0]; Channel* chan = ServerInstance->FindChan(channel); bool apply_other_sides_modes = true; if (!chan) { chan = new Channel(channel, TS); } else { time_t ourTS = chan->age; if (TS != ourTS) { ServerInstance->SNO->WriteToSnoMask('d', "Merge FJOIN received for %s, ourTS: %lu, TS: %lu, difference: %lu", chan->name.c_str(), (unsigned long)ourTS, (unsigned long)TS, (unsigned long)(ourTS - TS)); /* If our TS is less than theirs, we dont accept their modes */ if (ourTS < TS) { apply_other_sides_modes = false; } else if (ourTS > TS) { /* Our TS greater than theirs, clear all our modes from the channel, accept theirs. */ if (Utils->AnnounceTSChange) chan->WriteChannelWithServ(ServerInstance->Config->ServerName, "NOTICE %s :TS for %s changed from %lu to %lu", chan->name.c_str(), channel.c_str(), (unsigned long) ourTS, (unsigned long) TS); // while the name is equal in case-insensitive compare, it might differ in case; use the remote version chan->name = channel; chan->age = TS; chan->ClearInvites(); CommandFJoin::RemoveStatus(chan); // XXX: If the channel does not exist in the chan hash at this point, create it so the remote modes can be applied on it. // This happens to 0-user permanent channels on the losing side, because those are removed (from the chan hash, then // deleted later) as soon as the permchan mode is removed from them. if (ServerInstance->FindChan(channel) == NULL) { chan = new Channel(channel, TS); } } } } /* First up, apply their channel modes if they won the TS war */ if (apply_other_sides_modes) { std::vector<std::string> modelist; modelist.push_back(channel); /* Remember, params[params.size() - 1] is userlist, and we don't want to apply *that* */ modelist.insert(modelist.end(), params.begin()+2, params.end()-1); ServerInstance->SendMode(modelist, srcuser); } irc::modestacker modestack(true); TreeSocket* src_socket = Utils->FindServer(srcuser->server)->GetRoute()->GetSocket(); /* Now, process every 'modes,uuid' pair */ irc::tokenstream users(*params.rbegin()); std::string item; irc::modestacker* modestackptr = (apply_other_sides_modes ? &modestack : NULL); while (users.GetToken(item)) { if (!ProcessModeUUIDPair(item, src_socket, chan, modestackptr)) return CMD_INVALID; } /* Flush mode stacker if we lost the FJOIN or had equal TS */ if (apply_other_sides_modes) CommandFJoin::ApplyModeStack(srcuser, chan, modestack); return CMD_SUCCESS; }
/** FJOIN, almost identical to TS6 SJOIN, except for nicklist handling. */ CmdResult CommandFJoin::Handle(User* srcuser, Params& params) { /* 1.1+ FJOIN works as follows: * * Each FJOIN is sent along with a timestamp, and the side with the lowest * timestamp 'wins'. From this point on we will refer to this side as the * winner. The side with the higher timestamp loses, from this point on we * will call this side the loser or losing side. This should be familiar to * anyone who's dealt with dreamforge or TS6 before. * * When two sides of a split heal and this occurs, the following things * will happen: * * If the timestamps are exactly equal, both sides merge their privilages * and users, as in InspIRCd 1.0 and ircd2.8. The channels have not been * re-created during a split, this is safe to do. * * If the timestamps are NOT equal, the losing side removes all of its * modes from the channel, before introducing new users into the channel * which are listed in the FJOIN command's parameters. The losing side then * LOWERS its timestamp value of the channel to match that of the winning * side, and the modes of the users of the winning side are merged in with * the losing side. * * The winning side on the other hand will ignore all user modes from the * losing side, so only its own modes get applied. Life is simple for those * who succeed at internets. :-) * * Outside of netbursts, the winning side also resyncs the losing side if it * detects that the other side recreated the channel. * * Syntax: * :<sid> FJOIN <chan> <TS> <modes> :[<member> [<member> ...]] * The last parameter is a list consisting of zero or more channel members * (permanent channels may have zero users). Each entry on the list is in the * following format: * [[<modes>,]<uuid>[:<membid>] * <modes> is a concatenation of the mode letters the user has on the channel * (e.g.: "ov" if the user is opped and voiced). The order of the mode letters * are not important but if a server ecounters an unknown mode letter, it will * drop the link to avoid desync. * * InspIRCd 2.0 and older required a comma before the uuid even if the user * had no prefix modes on the channel, InspIRCd 3.0 and later does not require * a comma in this case anymore. * * <membid> is a positive integer representing the id of the membership. * If not present (in FJOINs coming from pre-1205 servers), 0 is assumed. * * Forwarding: * FJOIN messages are forwarded with the new TS and modes. Prefix modes of * members on the losing side are not forwarded. * This is required to only have one server on each side of the network who * decides the fate of a channel during a network merge. Otherwise, if the * clock of a server is slightly off it may make a different decision than * the rest of the network and desync. * The prefix modes are always forwarded as-is, or not at all. * One incoming FJOIN may result in more than one FJOIN being generated * and forwarded mainly due to compatibility reasons with non-InspIRCd * servers that don't handle more than 512 char long lines. * * Forwarding examples: * Existing channel #chan with TS 1000, modes +n. * Incoming: :220 FJOIN #chan 1000 +t :o,220AAAAAB:0 * Forwarded: :220 FJOIN #chan 1000 +nt :o,220AAAAAB:0 * Merge modes and forward the result. Forward their prefix modes as well. * * Existing channel #chan with TS 1000, modes +nt. * Incoming: :220 FJOIN #CHAN 2000 +i :ov,220AAAAAB:0 o,220AAAAAC:20 * Forwarded: :220 FJOIN #chan 1000 +nt :,220AAAAAB:0 ,220AAAAAC:20 * Drop their modes, forward our modes and TS, use our channel name * capitalization. Don't forward prefix modes. * */ time_t TS = ServerCommand::ExtractTS(params[1]); const std::string& channel = params[0]; Channel* chan = ServerInstance->FindChan(channel); bool apply_other_sides_modes = true; TreeServer* const sourceserver = TreeServer::Get(srcuser); if (!chan) { chan = new Channel(channel, TS); } else { time_t ourTS = chan->age; if (TS != ourTS) { ServerInstance->Logs.Log(MODNAME, LOG_DEBUG, "Merge FJOIN received for %s, ourTS: %lu, TS: %lu, difference: %ld", chan->name.c_str(), (unsigned long)ourTS, (unsigned long)TS, (long)(ourTS - TS)); /* If our TS is less than theirs, we dont accept their modes */ if (ourTS < TS) { // If the source server isn't bursting then this FJOIN is the result of them recreating the channel with a higher TS. // This happens if the last user on the channel hops and before the PART propagates a user on another server joins. Fix it by doing a resync. // Servers behind us won't react this way because the forwarded FJOIN will have the correct TS. if (!sourceserver->IsBursting()) { ServerInstance->Logs.Log(MODNAME, LOG_DEBUG, "Server %s recreated channel %s with higher TS, resyncing", sourceserver->GetName().c_str(), chan->name.c_str()); sourceserver->GetSocket()->SyncChannel(chan); } apply_other_sides_modes = false; } else if (ourTS > TS) { // Our TS is greater than theirs, remove all modes, extensions, etc. from the channel LowerTS(chan, TS, channel); // XXX: If the channel does not exist in the chan hash at this point, create it so the remote modes can be applied on it. // This happens to 0-user permanent channels on the losing side, because those are removed (from the chan hash, then // deleted later) as soon as the permchan mode is removed from them. if (ServerInstance->FindChan(channel) == NULL) { chan = new Channel(channel, TS); } } } } // Apply their channel modes if we have to Modes::ChangeList modechangelist; if (apply_other_sides_modes) { ServerInstance->Modes.ModeParamsToChangeList(srcuser, MODETYPE_CHANNEL, params, modechangelist, 2, params.size() - 1); ServerInstance->Modes.Process(srcuser, chan, NULL, modechangelist, ModeParser::MODE_LOCALONLY | ModeParser::MODE_MERGE); // Reuse for prefix modes modechangelist.clear(); } // Build a new FJOIN for forwarding. Put the correct TS in it and the current modes of the channel // after applying theirs. If they lost, the prefix modes from their message are not forwarded. FwdFJoinBuilder fwdfjoin(chan, sourceserver); // Process every member in the message irc::spacesepstream users(params.back()); std::string item; Modes::ChangeList* modechangelistptr = (apply_other_sides_modes ? &modechangelist : NULL); while (users.GetToken(item)) { ProcessModeUUIDPair(item, sourceserver, chan, modechangelistptr, fwdfjoin); } fwdfjoin.finalize(); fwdfjoin.Forward(sourceserver->GetRoute()); // Set prefix modes on their users if we lost the FJOIN or had equal TS if (apply_other_sides_modes) ServerInstance->Modes.Process(srcuser, chan, NULL, modechangelist, ModeParser::MODE_LOCALONLY); return CMD_SUCCESS; }