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"
30 * Yes, this function looks a little ugly.
31 * However, in some circumstances we may not have a User, so we need to do things this way.
32 * Returns true if remote or both lost, false otherwise.
33 * Sends SAVEs as appropriate and forces nick change of the user 'u' if our side loses or if both lose.
34 * Does not change the nick of the user that is trying to claim the nick of 'u', i.e. the "remote" user.
36 bool SpanningTreeUtilities::DoCollision(User* u, TreeServer* server, time_t remotets, const std::string& remoteident, const std::string& remoteip, const std::string& remoteuid, const char* collidecmd)
38 // At this point we're sure that a collision happened, increment the counter regardless of who wins
39 ServerInstance->stats.Collisions++;
42 * Under old protocol rules, we would have had to kill both clients.
44 * These days, we have UID. And, so what we do is, force nick change client(s)
45 * involved according to timestamp rules.
49 * Force nick change on OLDER timestamped client
51 * Force nick change on NEWER timestamped client
55 * This stops abusive use of collisions, simplifies problems with loops, and so on.
58 bool bChangeLocal = true;
59 bool bChangeRemote = true;
61 // If the timestamps are not equal only one of the users has to change nick,
62 // otherwise both have to change
63 const time_t localts = u->age;
64 if (remotets != localts)
66 /* first, let's see if ident@host matches. */
67 const std::string& localident = u->ident;
68 const std::string& localip = u->GetIPString();
69 bool SamePerson = (localident == remoteident)
70 && (localip == remoteip);
73 * if ident@ip is equal, and theirs is newer, or
74 * ident@ip differ, and ours is newer
76 if((SamePerson && remotets < localts) ||
77 (!SamePerson && remotets > localts))
79 // Only remote needs to change
84 // Only ours needs to change
85 bChangeRemote = false;
89 ServerInstance->Logs->Log(MODNAME, LOG_DEBUG, "Nick collision on \"%s\" caused by %s: %s/%lu/%s@%s %d <-> %s/%lu/%s@%s %d", u->nick.c_str(), collidecmd,
90 u->uuid.c_str(), (unsigned long)localts, u->ident.c_str(), u->GetIPString().c_str(), bChangeLocal,
91 remoteuid.c_str(), (unsigned long)remotets, remoteident.c_str(), remoteip.c_str(), bChangeRemote);
94 * Send SAVE and accept the losing client with its UID (as we know the SAVE will
95 * not fail under any circumstances -- UIDs are netwide exclusive).
97 * This means that each side of a collide will generate one extra NICK back to where
98 * they have just linked (and where it got the SAVE from), however, it will
99 * be dropped harmlessly as it will come in as :928AAAB NICK 928AAAB, and we already
100 * have 928AAAB's nick set to that.
107 * Local-side nick needs to change. Just in case we are hub, and
108 * this "local" nick is actually behind us, send a SAVE out.
110 CmdBuilder params("SAVE");
111 params.push(u->uuid);
112 params.push(ConvToStr(u->age));
115 u->ChangeNick(u->uuid, CommandSave::SavedTimestamp);
120 * Remote side needs to change. If this happens, we modify the UID or NICK and
121 * send back a SAVE to the source.
123 CmdBuilder("SAVE").push(remoteuid).push_int(remotets).Unicast(server->ServerUser);
126 return bChangeRemote;