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/*
* InspIRCd -- Internet Relay Chat Daemon
*
* Copyright (C) 2010 Daniel De Graaf <danieldg@inspircd.org>
* Copyright (C) 2008 Robin Burchell <robin+git@viroteck.net>
*
* This file is part of InspIRCd. InspIRCd is free software: you can
* redistribute it and/or modify it under the terms of the GNU General Public
* License as published by the Free Software Foundation, version 2.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "inspircd.h"
#include "commands.h"
#include "treesocket.h"
#include "treeserver.h"
#include "utils.h"
/** FTOPIC command */
CmdResult CommandFTopic::Handle(const std::vector<std::string>& params, User *user)
{
Channel* c = ServerInstance->FindChan(params[0]);
if ((!c) || (!IS_SERVER(user)))
return CMD_FAILURE;
/**
* Here's how this works:
*
* In pre-1204 protocol version we had a syntax like
*
* FTOPIC #chan topicts setby :topic
*
* where topicts is the time when the topic was set, and setby is the n!u@h
* of the user who set it. If the topicts value was bigger (newer) than our topic
* TS (stored in Channel::topicset), we accepted the change, else we assumed
* we already had a more recent topic and did nothing.
*
* However this behavior meant that if the channel was recreated on a server
* during a netsplit, users there could set any topic and override ours with it
* at merge because their topic had a newer topic TS.
* Protocol version 1204 addresses this issue by adding the channel TS to FTOPIC:
*
* FTOPIC #chan chants topicts setby :topic
*
* so we notice when the channel has been recreated and discard the FTOPIC in that case.
* Apart from this the logic remains the same. For previous versions not supporting the
* new syntax we need to fall back to the old behavior.
*
*/
// Determine the protocol version of the sender
SpanningTreeUtilities* Utils = ((ModuleSpanningTree*) (Module*) creator)->Utils;
TreeServer* srcserver = Utils->FindServer(user->server);
bool has_chants = (srcserver->Socket->proto_version >= 1204);
// If we got a channel TS compare it with ours. If it's different, drop the command.
// Also drop the command if we are using 1204, but there aren't enough parameters.
if (has_chants)
{
if (params.size() < 5)
return CMD_FAILURE;
// Only proceed if the TSes are equal. If their TS is newer the channel
// got recreated on their side, if it's older that means things are messed up,
// because they haven't sent us an FJOIN earlier which could lower the chan TS.
if (ConvToInt(params[1]) != c->age)
return CMD_FAILURE;
}
// Now do things as usual but if required, apply an offset to the index when accessing params
unsigned int indexoffset = (has_chants ? 1 : 0);
time_t topicts = ConvToInt(params[1+indexoffset]);
// See if the topic they sent is newer than ours (or we don't have a topic at all)
if ((topicts >= c->topicset) || (c->topic.empty()))
{
if (c->topic != params[3+indexoffset])
{
// Update topic only when it differs from current topic
c->topic.assign(params[3+indexoffset], 0, ServerInstance->Config->Limits.MaxTopic);
c->WriteChannel(user, "TOPIC %s :%s", c->name.c_str(), c->topic.c_str());
}
// Always update setter and settime.
c->setby.assign(params[2+indexoffset], 0, 127);
c->topicset = topicts;
}
else
{
// We got a newer topic than this one, keep ours and drop the command
return CMD_FAILURE;
}
// They haven't sent us a channel TS, add ours before passing the command on
if (!has_chants)
{
parameterlist& p = const_cast<parameterlist&>(params);
p.insert(p.begin()+1, ConvToStr(c->age));
}
return CMD_SUCCESS;
}
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