[paramiko] paramiko Digest, Vol 40, Issue 11

[Deepak Rokade]

Hi,
If we have got fix to deadlock in paramio issue ,
Are we planning any release with this fix ?
When can it be expected ?



------------------------------
>
> Message: 2
> Date: Fri, 18 Apr 2008 14:15:36 -0600
> From: Dwayne Litzenberger <dwayne at oscl.ca>
> Subject: [paramiko] [MERGE] Fix obscure deadlock that can occur during
>        re-keying
> To: paramiko at lag.net
> Message-ID: <200804181415.40332.dwayne at oscl.ca>
> Content-Type: text/plain; charset="iso-8859-1"
>
> Robey,
>
> I've attached a patch does the following:
>
> - Fix deadlock: Paramiko sometimes deadlocks if the user tries to send
> data
>  immediately after paramiko has initiated a key exchange (re-keying), but
>  before the remote MSG_KEXINIT has been received.  The deadlock occurs
> when
>  certain messages are received (e.g. MSG_CHANNEL_WINDOW_ADJUST) that were
>  in-transit when the initial MSG_KEXINIT was sent.
>
> - Add a test case for the deadlock
>
> - Fix __dump_packets support for SFTPServer and SFTPClient.  (Needed to
> make
> test.py work when Packetizer.__dump_packets = True.
>
> <shameless-plug>
> This patch took about 38 hours to produce, and was funded entirely by my
> employer, Open Systems Canada Limited.  They also paid for a lot of my
> work
> on the PRNG bugfixes (especially the as-yet unmerged rng*.py
> implementation).
> Basically, everything that came from my oscl.ca email address has been
> paid
> for by them.  It would be nice if they got some credit somewhere...
>  They're
> a small, FOSS-friendly IT services firm that could use the brand exposure.
> </shameless-plug>
>
> Cheers,
>  - Dwayne
>
> On April 15, 2008 04:58:05 pm Dwayne Litzenberger wrote:
> > On April 15, 2008 01:03:00 pm Dwayne Litzenberger wrote:
> > > In the main thread:
> > >
> > > Channel.send acquires Channel.lock, calls
> Channel._wait_for_send_window,
> > > then calls Transport._send_user_message with a MSG_CHANNEL_DATA
> message.
> > > Transport._send_user_message then waits for Transport.clear_to_send to
> be
> > > set, but it's not set for some reason.  Note that Channel.lock is
> still
> > > held by the main thread.
> > >
> > > Meanwhile, the Transport thread tries to process a MSG_WINDOW_ADJUST
> > > message. It calls Channel._window_adjust, but that can't proceed until
> > > Channel.lock is released.
> >
> > clear_to_send is unset (correctly) because we've just sent MSG_KEXINIT.
> > The problem seems to be that Channel.send() is holding Channel.lock,
> thus
> > preventing still-in-transit messages like MSG_WINDOW_ADJUST from being
> > processed by the Transport thread, even though we haven't received the
> > remote side's MSG_KEXINIT yet.
>
> --
> Dwayne Litzenberger, B.A.Sc.
> Information Technology Analyst
>
> Open Systems Canada Limited
> #210 - 2332 11th Ave
> Regina, SK S4P0K1
> Office: (306) 359-OSCL (6725)
> http://www.oscl.ca/
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> End of paramiko Digest, Vol 40, Issue 11
> ****************************************
>



-- 
Thanx & Regards,
Deepak Rokade

Do what u Enjoy &
Enjoy what u Do...........
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