SCP Problem

[Roger Oberholtzer]

On Wed, 2007-10-24 at 20:38 -0400, Kurt Wall wrote:
> Hola, list,
> 
> I have an interesting problem. The short version is that there is host
> out there into which I can ssh without incident from my systems here
> at KurtWerks (using either password or public key authentication - I 
> use public keys). I can also ssh back to KurtWerks. Similarly, from the
> remote host, I can scp files to and from KurtWerks. 
> 
> The problem, though, is that scp from KurtWerks to the remote system, that
> is, when KurtWerks is the orgin of the scp session, will not work. I
> start the session, authenticate, and then it stops. No data is
> transmitted. When I turn debugging with scp -vvv, the last few lines
> read like so:
> 
> debug1: Sending command: scp -v -r -p -d -t /usr/www/users/kwall
> debug2: channel 0: request exec confirm 0
> debug2: fd 3 setting TCP_NODELAY
> debug2: callback done
> debug2: channel 0: open confirm rwindow 0 rmax 32768
> debug2: channel 0: rcvd adjust 131072 
> 
> That last line is the last thing I see; 10 minutes later, it hasn't
> moved and I just kill the session with Ctrl-c. I ran an strace on the
> scp session, and the last few lines look like so:
> 
> rt_sigaction(SIGTERM, NULL, {SIG_DFL}, 8) = 0
> rt_sigaction(SIGTERM, {0x80001d50, [], 0}, NULL, 8) = 0
> rt_sigaction(SIGINT, NULL, {SIG_DFL}, 8) = 0
> rt_sigaction(SIGINT, {0x80001d50, [], 0}, NULL, 8) = 0
> rt_sigaction(SIGHUP, NULL, {SIG_DFL}, 8) = 0
> rt_sigaction(SIGHUP, {0x80001d50, [], 0}, NULL, 8) = 0
> read(7,

sco is waiting for data on descriptor 7 in a blocking read without a
timeout (nice robust programming, BTW). Who is file descriptor 7? I
think the strace info is more meaningful for this than /proc/xxx/fd,
which will probably list it as a pipe, which in not very informative.

-- 
Roger Oberholtzer

OPQ Systems / Ramböll RST

Ramböll Sverige AB
Kapellgränd 7
P.O. Box 4205
SE-102 65 Stockholm, Sweden

Tel: Int +46 8-615 60 20
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