2 * InspIRCd -- Internet Relay Chat Daemon
4 * Copyright (C) 2009 Daniel De Graaf <danieldg@inspircd.org>
5 * Copyright (C) 2008 Robin Burchell <robin+git@viroteck.net>
7 * This file is part of InspIRCd. InspIRCd is free software: you can
8 * redistribute it and/or modify it under the terms of the GNU General Public
9 * License as published by the Free Software Foundation, version 2.
11 * This program is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
13 * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
16 * You should have received a copy of the GNU General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
23 #include "treesocket.h"
24 #include "treeserver.h"
26 #include "commandbuilder.h"
29 * Yes, this function looks a little ugly.
30 * However, in some circumstances we may not have a User, so we need to do things this way.
31 * Returns 1 if colliding local client, 2 if colliding remote, 3 if colliding both.
32 * Sends SAVEs as appropriate and forces nickchanges too.
34 int SpanningTreeUtilities::DoCollision(User* u, TreeServer* server, time_t remotets, const std::string& remoteident, const std::string& remoteip, const std::string& remoteuid)
37 * Under old protocol rules, we would have had to kill both clients.
39 * These days, we have UID. And, so what we do is, force nick change client(s)
40 * involved according to timestamp rules.
44 * Force nick change on OLDER timestamped client
46 * Force nick change on NEWER timestamped client
50 * This stops abusive use of collisions, simplifies problems with loops, and so on.
53 bool bChangeLocal = true;
54 bool bChangeRemote = true;
56 /* for brevity, don't use the User - use defines to avoid any copy */
57 #define localts u->age
58 #define localident u->ident
59 #define localip u->GetIPString()
61 /* mmk. let's do this again. */
62 if (remotets == localts)
64 /* equal. fuck them both! do nada, let the handler at the bottom figure this out. */
68 /* fuck. now it gets complex. */
70 /* first, let's see if ident@host matches. */
71 bool SamePerson = (localident == remoteident)
72 && (localip == remoteip);
75 * if ident@ip is equal, and theirs is newer, or
76 * ident@ip differ, and ours is newer
78 if((SamePerson && remotets < localts) ||
79 (!SamePerson && remotets > localts))
81 /* remote needs to change */
86 /* ours needs to change */
87 bChangeRemote = false;
92 * Cheat a little here. Instead of a dedicated command to change UID,
93 * use SAVE and accept the losing client with its UID (as we know the SAVE will
94 * not fail under any circumstances -- UIDs are netwide exclusive).
96 * This means that each side of a collide will generate one extra NICK back to where
97 * they have just linked (and where it got the SAVE from), however, it will
98 * be dropped harmlessly as it will come in as :928AAAB NICK 928AAAB, and we already
99 * have 928AAAB's nick set to that.
106 * Local-side nick needs to change. Just in case we are hub, and
107 * this "local" nick is actually behind us, send an SAVE out.
109 CmdBuilder params("SAVE");
110 params.push_back(u->uuid);
111 params.push_back(ConvToStr(u->age));
114 u->ForceNickChange(u->uuid);
121 User *remote = ServerInstance->FindUUID(remoteuid);
123 * remote side needs to change. If this happens, we will modify
124 * the UID or halt the propagation of the nick change command,
125 * so other servers don't need to see the SAVE
127 TreeSocket* sock = server->GetSocket();
128 sock->WriteLine(":"+ServerInstance->Config->GetSID()+" SAVE "+remoteuid+" "+ ConvToStr(remotets));
132 /* nick change collide. Force change their nick. */
133 remote->ForceNickChange(remoteuid);