Bug 1395

Summary:

"session_input_channel_req: no session" should be a debug message

Product:

Portable OpenSSH

Reporter:

Ben Harris <bjh21>

Component:

sshd

Assignee:

Assigned to nobody <unassigned-bugs>

Status:

CLOSED FIXED

Severity:

minor

CC:

djm, dtucker

Priority:

Keywords:

patch

Version:

5.0p1

Hardware:

All

OS:

All

Bug Depends on:

Bug Blocks:

1452

Attachments:

Description	Flags
Possible patch to turn this into a debug message (compile-tested only)	none
only pass requests on session channels through to session handler	none

Description Ben Harris 2007-12-04 05:21:18 AEDT

Created attachment 1385 [details]
Possible patch to turn this into a debug message (compile-tested only)

When sshd receives a channel request on a non-session channel, it writes a log message about it.  This is in contrast to channel requests on non-session channels, which only merit a debug message.  This is a bit of a nuisance because development versions of PuTTY use an undefined channel request ("winadj@putty.projects.tartarus.org") to work out the right window size to use on a channel, causing a slew of:

Dec  3 18:03:07 viking sshd[6386]: session_input_channel_req: no session 1 req winadj@putty.projects.tartarus.org

Comment 1 Damien Miller 2008-01-20 09:53:37 AEDT

why is putty sending window probe requests on these channels anyway?

Comment 2 Ben Harris 2008-01-22 05:10:43 AEDT

It's PuTTY's mechanism for deciding what channel window size it should 
use.  From the relevant wishlist item:

The basic idea is that when the connection isn't being limited by our 
ability to process data, we want to ensure that the window size as seen by 
the server never drops to zero. Measuring the server's view of the window 
size is done by arranging for it to acknowledge every 
SSH_MSG_CHANNEL_WINDOW_ADJUST, or rather an SSH_MSG_CHANNEL_REQUEST sent 
just before it. That way we can tell when it its outgoing data stream it 
recieved the window adjustment, and thus how small the server's view of 
the window got.
<http://www.chiark.greenend.org.uk/~sgtatham/putty/wishlist/flow-control>

Comment 3 Ben Harris 2008-01-22 05:13:19 AEDT

Note in case it's causing confusion: this is the flow-control window, as set by SSH_MSG_CHANNEL_WINDOW_ADJUST, not the terminal window, as set by SSH_MSG_CHANNEL_REQUEST("window-change").

Comment 4 Damien Miller 2008-06-30 22:12:32 AEST

Created attachment 1537 [details]
only pass requests on session channels through to session handler

I think this fix is better: only pass channel requests on session channels through to the session channel handler.

Comment 5 Damien Miller 2008-06-30 22:16:42 AEST

fix has been committed, will be in openssh-5.1

Comment 6 Damien Miller 2008-07-22 12:20:29 AEST

Mass update RESOLVED->CLOSED after release of openssh-5.1