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Re: SSH channel forwarding fails on ieof


It's a pity but it seems I was in hurry. The issue is still reproducing on some machines.
The error code is the same

channel_by_id: 0: bad id: channel free

But issue is not stable - reproduces on specific machines only


On 09/25/2013 04:27 AM, Pugnator wrote:
Thanks a lot for your reply.
Yes, it is the case for me as I'm creating multiple channels simultaneously. I used stable repo from Debian 7. I followed your suggestion and compiled 0.6rc.
The issue was not reproduced after it.


On 09/25/2013 12:36 AM, Aris Adamantiadis wrote:
Hi,

Could you try again with libssh 0.5.5 or 0.6rc and tell me if you can
reproduce the problem ? This behaviour recalls me of a bug that has been
fixed in 0.5.3, and would happen when you open multiple channels. Is it
the case ?

Thanks,

Aris

Le 24/09/13 18:21, Pugnator a écrit :
I use libssh 0.5.2 binding for C under Linux. In my program I create SSH
tunnel to XenServer. It worked perfectly until I updated to the most
recent XenServer 6.2. After it ssh tunneling started failing with

[1] Analyzing banner: SSH-2.0-OpenSSH_4.3
[1] We are talking to an OpenSSH client version: 4.3 (40300)
[1] placing 18 bytes into channel buffer (stderr=0)
[1] Error : Channel opening failure: channel 44 error (2) Connection
refused

On server side there is records in /var/log/secure:

Sep 24 20:12:10 proxima sshd[20782]: pam_unix(sshd:session): session
opened for user root by (uid=0)
Sep 24 20:12:10 proxima sshd[20792]: Accepted password for root from
10.250.144.221 port 55673 ssh2
Sep 24 20:12:10 proxima sshd[20792]: pam_unix(sshd:session): session
opened for user root by (uid=0)
Sep 24 20:12:11 proxima sshd[16132]: channel_by_id: 0: bad id: channel free
Sep 24 20:12:11 proxima sshd[16132]: Disconnecting: Received ieof for
nonexistent channel 0.
Sep 24 20:12:11 proxima sshd[16132]: pam_unix(sshd:session): session
closed for user root


The most strange is the ssh server version is the same on old and new
servers:
OpenSSH_4.3p2, OpenSSL 0.9.8e-fips-rhel5 01 Jul 2008

I'm not sure how to debug such an issue. Sometimes tunnel establishes
and works but it is 1 out of 100 tries.






Follow-Ups:
Re: SSH channel forwarding fails on ieofAris Adamantiadis <aris@xxxxxxxxxxxx>
References:
Dropbear support?Adrian Baerlocher <adrian@xxxxxxxxxxxx>
Re: Dropbear support?Andreas Schneider <asn@xxxxxxxxxxxxxx>
Re: Dropbear support?Adrian Baerlocher <adrian@xxxxxxxxxxxx>
SSH channel forwarding fails on ieofPugnator <ookami@xxxxxxx>
Re: SSH channel forwarding fails on ieofAris Adamantiadis <aris@xxxxxxxxxxxx>
Re: SSH channel forwarding fails on ieofPugnator <ookami@xxxxxxx>
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