Module: ngircd.git Branch: master Commit: 684e50f0a4d827965b61c4b9feeda403ec3c3b87 URL: http://ngircd.barton.de/cgi-bin/gitweb.cgi?p=ngircd.git&a=commit;h=684e5...
Author: Alexander Barton alex@barton.de Date: Sat Jun 9 01:03:48 2012 +0200
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.
---
src/ngircd/conf.c | 10 +++++++++- src/ngircd/conn.c | 12 ++++++++++-- 2 files changed, 19 insertions(+), 3 deletions(-)
diff --git a/src/ngircd/conf.c b/src/ngircd/conf.c index 5426900..f274eb8 100644 --- a/src/ngircd/conf.c +++ b/src/ngircd/conf.c @@ -1,6 +1,6 @@ /* * 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 * 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( 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; }
diff --git a/src/ngircd/conn.c b/src/ngircd/conn.c index 09f726c..06236fd 100644 --- a/src/ngircd/conn.c +++ b/src/ngircd/conn.c @@ -1,6 +1,6 @@ /* * 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 * 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 );
+ /* 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)) { Log(LOG_WARNING, "New_Server: Could not convert IP to string"); return; @@ -2008,7 +2016,7 @@ New_Server( int Server , ng_ipaddr_t *dest) Client_SetToken( c, TOKEN_OUTBOUND );
/* 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].addr = *dest; My_Connections[new_sock].client = c;