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"
28 * Yes, this function looks a little ugly.
29 * However, in some circumstances we may not have a User, so we need to do things this way.
30 * Returns 1 if colliding local client, 2 if colliding remote, 3 if colliding both.
31 * Sends SAVEs as appropriate and forces nickchanges too.
33 int SpanningTreeUtilities::DoCollision(User* u, TreeServer* server, time_t remotets, const std::string& remoteident, const std::string& remoteip, const std::string& remoteuid)
36 * Under old protocol rules, we would have had to kill both clients.
38 * These days, we have UID. And, so what we do is, force nick change client(s)
39 * involved according to timestamp rules.
43 * Force nick change on OLDER timestamped client
45 * Force nick change on NEWER timestamped client
49 * This stops abusive use of collisions, simplifies problems with loops, and so on.
52 bool bChangeLocal = true;
53 bool bChangeRemote = true;
55 /* for brevity, don't use the User - use defines to avoid any copy */
56 #define localts u->age
57 #define localident u->ident
58 #define localip u->GetIPString()
60 /* mmk. let's do this again. */
61 if (remotets == localts)
63 /* equal. fuck them both! do nada, let the handler at the bottom figure this out. */
67 /* fuck. now it gets complex. */
69 /* first, let's see if ident@host matches. */
70 bool SamePerson = (localident == remoteident)
71 && (localip == remoteip);
74 * if ident@ip is equal, and theirs is newer, or
75 * ident@ip differ, and ours is newer
77 if((SamePerson && remotets < localts) ||
78 (!SamePerson && remotets > localts))
80 /* remote needs to change */
85 /* ours needs to change */
86 bChangeRemote = false;
91 * Cheat a little here. Instead of a dedicated command to change UID,
92 * use SAVE and accept the losing client with its UID (as we know the SAVE will
93 * not fail under any circumstances -- UIDs are netwide exclusive).
95 * This means that each side of a collide will generate one extra NICK back to where
96 * they have just linked (and where it got the SAVE from), however, it will
97 * be dropped harmlessly as it will come in as :928AAAB NICK 928AAAB, and we already
98 * have 928AAAB's nick set to that.
105 * Local-side nick needs to change. Just in case we are hub, and
106 * this "local" nick is actually behind us, send an SAVE out.
108 parameterlist params;
109 params.push_back(u->uuid);
110 params.push_back(ConvToStr(u->age));
111 this->DoOneToMany(ServerInstance->Config->GetSID(),"SAVE",params);
113 u->ForceNickChange(u->uuid);
120 User *remote = ServerInstance->FindUUID(remoteuid);
122 * remote side needs to change. If this happens, we will modify
123 * the UID or halt the propagation of the nick change command,
124 * so other servers don't need to see the SAVE
126 TreeSocket* sock = server->GetSocket();
127 sock->WriteLine(":"+ServerInstance->Config->GetSID()+" SAVE "+remoteuid+" "+ ConvToStr(remotets));
131 /* nick change collide. Force change their nick. */
132 remote->ForceNickChange(remoteuid);