1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
|
/*
* InspIRCd -- Internet Relay Chat Daemon
*
* Copyright (C) 2019 Sadie Powell <sadie@witchery.services>
* Copyright (C) 2013-2015 Attila Molnar <attilamolnar@hush.com>
* Copyright (C) 2012 Robby <robby@chatbelgie.be>
* Copyright (C) 2009 Uli Schlachter <psychon@inspircd.org>
* Copyright (C) 2009 Daniel De Graaf <danieldg@inspircd.org>
* Copyright (C) 2008, 2010 Craig Edwards <brain@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 "treesocket.h"
#include "treeserver.h"
#include "utils.h"
#include "commandbuilder.h"
#include "commands.h"
/*
* Yes, this function looks a little ugly.
* However, in some circumstances we may not have a User, so we need to do things this way.
* Returns true if remote or both lost, false otherwise.
* Sends SAVEs as appropriate and forces nick change of the user 'u' if our side loses or if both lose.
* Does not change the nick of the user that is trying to claim the nick of 'u', i.e. the "remote" user.
*/
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)
{
// At this point we're sure that a collision happened, increment the counter regardless of who wins
ServerInstance->stats.Collisions++;
/*
* Under old protocol rules, we would have had to kill both clients.
* Really, this sucks.
* These days, we have UID. And, so what we do is, force nick change client(s)
* involved according to timestamp rules.
*
* RULES:
* user@ip equal:
* Force nick change on OLDER timestamped client
* user@ip differ:
* Force nick change on NEWER timestamped client
* TS EQUAL:
* FNC both.
*
* This stops abusive use of collisions, simplifies problems with loops, and so on.
* -- w00t
*/
bool bChangeLocal = true;
bool bChangeRemote = true;
// If the timestamps are not equal only one of the users has to change nick,
// otherwise both have to change
const time_t localts = u->age;
if (remotets != localts)
{
/* first, let's see if ident@host matches. */
const std::string& localident = u->ident;
const std::string& localip = u->GetIPString();
bool SamePerson = (localident == remoteident)
&& (localip == remoteip);
/*
* if ident@ip is equal, and theirs is newer, or
* ident@ip differ, and ours is newer
*/
if((SamePerson && remotets < localts) ||
(!SamePerson && remotets > localts))
{
// Only remote needs to change
bChangeLocal = false;
}
else
{
// Only ours needs to change
bChangeRemote = false;
}
}
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,
u->uuid.c_str(), (unsigned long)localts, u->ident.c_str(), u->GetIPString().c_str(), bChangeLocal,
remoteuid.c_str(), (unsigned long)remotets, remoteident.c_str(), remoteip.c_str(), bChangeRemote);
/*
* Send SAVE and accept the losing client with its UID (as we know the SAVE will
* not fail under any circumstances -- UIDs are netwide exclusive).
*
* This means that each side of a collide will generate one extra NICK back to where
* they have just linked (and where it got the SAVE from), however, it will
* be dropped harmlessly as it will come in as :928AAAB NICK 928AAAB, and we already
* have 928AAAB's nick set to that.
* -- w00t
*/
if (bChangeLocal)
{
/*
* Local-side nick needs to change. Just in case we are hub, and
* this "local" nick is actually behind us, send a SAVE out.
*/
CmdBuilder params("SAVE");
params.push(u->uuid);
params.push(ConvToStr(u->age));
params.Broadcast();
u->ChangeNick(u->uuid, CommandSave::SavedTimestamp);
}
if (bChangeRemote)
{
/*
* Remote side needs to change. If this happens, we modify the UID or NICK and
* send back a SAVE to the source.
*/
CmdBuilder("SAVE").push(remoteuid).push_int(remotets).Unicast(server->ServerUser);
}
return bChangeRemote;
}
|
