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ngircd-tor
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Correctly handle asynchronously re-established server links 

Don't try to establish an outgoing server link after DNS lookup when this
server re-connected on its own in the meantime.
In addition, log a warning message if we try to update the connection
index of an already connected server structure -- and ignore it.

Up to now, both behaviour could lead to a race when the remote server
connects to this daemon while it still prepares the outgoing connection:

 - The local server prepares the new outgoing connection ...
 - in the meantime the remote server becomes connected and registered.
 - Now the new outgoing connection overwrites the (correct) socket handle,
 - then the 2nd connection becomes disconnected: "already registered",
 - and the 1st connection becomes unhandled ("gets lost") because the
   configuration structure is reset because of the wrong socket handle.

This patch hopefully fixes all these problems.
This commit is contained in:
Alexander Barton 2012-06-09 01:03:48 +02:00
parent 4a90959cb5
commit 684e50f0a4
2 changed files with 19 additions and 3 deletions
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10
src/ngircd/conf.c
View File

@ -1,6 +1,6 @@
/* /*
* ngIRCd -- The Next Generation IRC Daemon * ngIRCd -- The Next Generation IRC Daemon
* Copyright (c)2001-2011 Alexander Barton (alex@barton.de) and Contributors. * Copyright (c)2001-2012 Alexander Barton (alex@barton.de) and Contributors.
* *
* This program is free software; you can redistribute it and/or modify * This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by * it under the terms of the GNU General Public License as published by
@ -492,6 +492,14 @@ Conf_SetServer( int ConfServer, CONN_ID Idx )
assert( ConfServer > NONE ); assert( ConfServer > NONE );
assert( Idx > NONE ); assert( Idx > NONE );
if (Conf_Server[ConfServer].conn_id > NONE &&
Conf_Server[ConfServer].conn_id != Idx) {
Log(LOG_ALERT,
"Trying to update connection index for already registered server \"%s\": %d/%d - ignored.",
Conf_Server[ConfServer].name,
Conf_Server[ConfServer].conn_id, Idx);
return;
}
Conf_Server[ConfServer].conn_id = Idx; Conf_Server[ConfServer].conn_id = Idx;
} }

12
src/ngircd/conn.c
View File

@ -1,6 +1,6 @@
/* /*
* ngIRCd -- The Next Generation IRC Daemon * ngIRCd -- The Next Generation IRC Daemon
* Copyright (c)2001-2011 Alexander Barton (alex@barton.de) and Contributors. * Copyright (c)2001-2012 Alexander Barton (alex@barton.de) and Contributors.
* *
* This program is free software; you can redistribute it and/or modify * This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by * it under the terms of the GNU General Public License as published by
@ -1935,6 +1935,14 @@ New_Server( int Server , ng_ipaddr_t *dest)
assert( Server > NONE ); assert( Server > NONE );
/* Make sure that the remote server hasn't re-linked to this server
* asynchronously on its own */
if (Conf_Server[Server].conn_id > NONE) {
Log(LOG_INFO,
"Connection to \"%s\" meanwhile re-established, aborting preparation.");
return;
}
if (!ng_ipaddr_tostr_r(dest, ip_str)) { if (!ng_ipaddr_tostr_r(dest, ip_str)) {
Log(LOG_WARNING, "New_Server: Could not convert IP to string"); Log(LOG_WARNING, "New_Server: Could not convert IP to string");
return; return;
@ -2008,7 +2016,7 @@ New_Server( int Server , ng_ipaddr_t *dest)
Client_SetToken( c, TOKEN_OUTBOUND ); Client_SetToken( c, TOKEN_OUTBOUND );
/* Register connection */ /* Register connection */
Conf_Server[Server].conn_id = new_sock; Conf_SetServer(Server, new_sock);
My_Connections[new_sock].sock = new_sock; My_Connections[new_sock].sock = new_sock;
My_Connections[new_sock].addr = *dest; My_Connections[new_sock].addr = *dest;
My_Connections[new_sock].client = c; My_Connections[new_sock].client = c;