openssh unix dev - Jul 2000 - scp not shutting down in 2.1.1p4

Hi!

as I just noted, after scp the connection does not shut down properly.

When I do a "scp file targethost:path", on targethost a
"sshd" process is
left running. I do use
  --with-default-path="/usr/local/openssh/bin:/usr/bin:/usr/local/bin"
to assure, that the corrensponding openssh-scp is used.
It also seems, that normal sessions are not always closed properly.

I run OpenSSH 2.1.1p4 (with the startup_pipe = -1; patch posted yesterday,
but that should not matter here) on HP-UX 10.20.

Any ideas what to do or what to look for? The behaviour occurs with
both ssh-1.2.27 "scp" and openssh "scp".

Best regards,
	Lutz
-- 
Lutz Jaenicke                             Lutz.Jaenicke at aet.TU-Cottbus.DE
BTU Cottbus               http://www.aet.TU-Cottbus.DE/personen/jaenicke/
Lehrstuhl Allgemeine Elektrotechnik                  Tel. +49 355 69-4129
Universitaetsplatz 3-4, D-03044 Cottbus              Fax. +49 355 69-4153

On Tue, Jul 18, 2000 at 11:24:32AM +0200, Lutz Jaenicke
wrote:
> When I do a "scp file targethost:path", on targethost a
"sshd" process is
> left running. I do use
>  
--with-default-path="/usr/local/openssh/bin:/usr/bin:/usr/local/bin"
> to assure, that the corrensponding openssh-scp is used.
> It also seems, that normal sessions are not always closed properly.
Oops, I withdraw this last remark. I had a window open on another host
that was still listed.
	Lutz
-- 
Lutz Jaenicke                             Lutz.Jaenicke at aet.TU-Cottbus.DE
BTU Cottbus               http://www.aet.TU-Cottbus.DE/personen/jaenicke/
Lehrstuhl Allgemeine Elektrotechnik                  Tel. +49 355 69-4129
Universitaetsplatz 3-4, D-03044 Cottbus              Fax. +49 355 69-4153

On Tue, Jul 18, 2000 at 11:24:32AM +0200, Lutz Jaenicke
wrote:
> Hi!
> 
> as I just noted, after scp the connection does not shut down properly.
> 
> When I do a "scp file targethost:path", on targethost a
"sshd" process is
> left running. I do use
>  
--with-default-path="/usr/local/openssh/bin:/usr/bin:/usr/local/bin"
> to assure, that the corrensponding openssh-scp is used.
In the good old habit of following up to myself :-)

I have by now investigated the behaviour a bit more and of course, when
doing a "ps -ef | grep sshd", it seems that the sshd-processes are
hanging
around.
Of course, when looking a bit more precise "ps -ef | grep scp", the
corresponding scp-processes are still around on the server, so that the
sshd-processes will not terminate. That brings the problem down to the
problem, why the remote scp processes won't die.
(The are called in sink-mode (-t) and the copying is completed ok.
When used in source mode (scp sourcehost:path localfile), it seems to
work ok.)
The calling "scp" process also does not terminate but seems to go to
background(?) (is still in the process list) because I can continue the work,
but still get the error message (e.g. broken pipe) when I kill the hung
scp process on the targethost.

Hmm, still digging in the scp source...

Best regards,
	Lutz
-- 
Lutz Jaenicke                             Lutz.Jaenicke at aet.TU-Cottbus.DE
BTU Cottbus               http://www.aet.TU-Cottbus.DE/personen/jaenicke/
Lehrstuhl Allgemeine Elektrotechnik                  Tel. +49 355 69-4129
Universitaetsplatz 3-4, D-03044 Cottbus              Fax. +49 355 69-4153

On Tue, Jul 18, 2000 at 02:55:44PM +0200, Lutz Jaenicke
wrote:
> Hmm, still digging in the scp source...
do you have problems with
	$ ssh host cat file > ~/tmp/x
too?

-markus

On Tue, 18 Jul 2000, Markus Friedl wrote:
: On Tue, Jul 18, 2000 at 02:55:44PM +0200, Lutz Jaenicke wrote:
: > Hmm, still digging in the scp source...
: 
: do you have problems with
: 	$ ssh host cat file > ~/tmp/x
: too?

That works fine.

Here are some trace (tusc) and stacks traces from HP-UX 11.0.

scp trace output:

write(2, "5 3   X \n", 5)
...................................................... = 5
write(6, "C 0 6 6 4   5 3   X \n", 11)
......................................... = 11
read(7, "\0", 1)
............................................................... = 1
fstat(3, 0x7bff1084) ...........................................................
= 0
gettimeofday(0x40002780, NULL) .................................................
= 0
setpgrp(0) .....................................................................
= 8809
ioctl(1, TIOCGPGRP, 0x7bff1280) ................................................
= 0
gettimeofday(0x7bff10b0, NULL) .................................................
= 0
ioctl(1, TIOCGWINSZ, 0x7bff1280) ...............................................
= 0
X                      0% |                                                   | 
0       --:-- ETAwrite(1, "\rX                             ".., 102)
............................ = 102
sigsetreturn(0x7bfcba1a, 0x6211988, 1392) ......................................
= 0
sigaction(SIGALRM, 0x7bff11e8, NULL) ...........................................
= 0
setitimer(ITIMER_REAL, 0x7bff1280, NULL) .......................................
= 0
read(3, "G e n e r i c S y s N a m e   [ ".., 53)
.............................. = 53
write(6, "G e n e r i c S y s N a m e   [ ".., 53)
............................. = 53
ioctl(1, TIOCGPGRP, 0x7bff1280) ................................................
= 0
gettimeofday(0x7bff10b0, NULL) .................................................
= 0
ioctl(1, TIOCGWINSZ, 0x7bff1280) ...............................................
= 0
X                    100% |***************************************************| 
53       00:00    write(1, "\rX                             ".., 102)
............................ = 102
setitimer(ITIMER_REAL, 0x7bff1280, NULL) .......................................
= 0

write(1, "\n", 1)
.............................................................. = 1
close(3) .......................................................................
= 0
write(6, "\0", 1)
.............................................................. = 1
read(7, "\0", 1)
............................................................... = 1
exit(0) ........................................................................
WIFEXITED(0)

stack trace of blocked scp ssh child:

(gdb) attach 8613
Attaching to process 8613
Reading symbols from /opt/openssh-2.1.1p4/bin/ssh...done.
warning: The shared libraries were not privately mapped; setting a
breakpoint in a shared library will not work until you rerun the program.

Reading symbols from /usr/lib/libnsl.1...done.
Reading symbols from /usr/lib/libxti.2...done.
Reading symbols from /usr/lib/libsec.2...done.
Reading symbols from /usr/lib/libm.2...done.
Reading symbols from /usr/lib/libpam.1...done.
Reading symbols from /usr/lib/libc.2...done.
Reading symbols from /usr/lib/libdld.2...done.
Reading symbols from /usr/lib/libnss_files.1...done.
Reading symbols from /usr/lib/libnss_dns.1...done.
0xc01ed428 in _select_sys () from /usr/lib/libc.2
(gdb) bt
#0  0xc01ed428 in _select_sys () from /usr/lib/libc.2
#1  0xc01f8fa8 in select () from /usr/lib/libc.2
#2  0x1a004 in client_wait_until_can_do_something (readset=0x7bff0ddc,
writeset=0x7bff0edc)
    at clientloop.c:368
#3  0x1b248 in client_loop (have_pty=0, escape_char_arg=-1) at clientloop.c:824
#4  0x12a48 in ssh_session () at ssh.c:874
#5  0x12000 in main (ac=5, av=0x7bff0514) at ssh.c:670

stack trace of server blocked sshd:

Attaching to process 8777
Reading symbols from /opt/ssh/sbin/sshd...done.
warning: The shared libraries were not privately mapped; setting a
breakpoint in a shared library will not work until you rerun the program.

Reading symbols from /usr/lib/libnsl.1...done.
Reading symbols from /usr/lib/libxti.2...done.
Reading symbols from /usr/lib/libsec.2...done.
Reading symbols from /usr/lib/libm.2...done.
Reading symbols from /usr/lib/libpam.1...done.
Reading symbols from /usr/lib/libc.2...done.
Reading symbols from /usr/lib/libdld.2...done.
Reading symbols from /usr/lib/libnss_files.1...done.
Reading symbols from /usr/lib/libnss_dns.1...done.
Reading symbols from /usr/lib/security/libpam_unix.1...done.
Reading symbols from /usr/lib/libpsm.1...done.
0xc01ed428 in _select_sys () from /usr/lib/libc.2
(gdb) bt
#0  0xc01ed428 in _select_sys () from /usr/lib/libc.2
#1  0xc01f8fa8 in select () from /usr/lib/libc.2
#2  0x1b90c in wait_until_can_do_something (readset=0x7bff0ea8,
writeset=0x7bff0fa8,
    max_time_milliseconds=0) at serverloop.c:232
#3  0x1c490 in server_loop (pid=8778, fdin_arg=8, fdout_arg=8, fderr_arg=10) at
serverloop.c:519
#4  0x1e408 in do_exec_no_pty (s=0x4001d540, command=0x4002c910 "scp -t
y", pw=0x7bff0cac)
    at session.c:500
#5  0x1e060 in do_authenticated (pw=0x7bff0cac) at session.c:358
#6  0x13d08 in do_authentication () at auth1.c:535
#7  0x12010 in main (ac=1, av=0x7bff02c4) at sshd.c:1003

stack trace "hung" scp process:

Attaching to process 8893
Reading symbols from /usr/src/openssh/openssh-2.1.1p4/scp...done.
warning: The shared libraries were not privately mapped; setting a
breakpoint in a shared library will not work until you rerun the program.

Reading symbols from /usr/lib/libnsl.1...done.
Reading symbols from /usr/lib/libxti.2...done.
Reading symbols from /usr/lib/libsec.2...done.
Reading symbols from /usr/lib/libm.2...done.
Reading symbols from /usr/lib/libpam.1...done.
Reading symbols from /usr/lib/libc.2...done.
Reading symbols from /usr/lib/libdld.2...done.
Reading symbols from /usr/lib/libnss_files.1...done.
0xc01ed230 in _read_sys () from /usr/lib/libc.2
(gdb) bt
#0  0xc01ed230 in _read_sys () from /usr/lib/libc.2
#1  0xc01f85e4 in read () from /usr/lib/libc.2
#2  0x82a8 in atomicio (f=0x400026d2 <SD$endc+122>, fd=0, _s=0x7bff03c0
"C0664 53 X", n=1) at atomicio.c:46
#3  0x625c in sink (argc=1, argv=0x7bff014c) at scp.c:702
#4  0x4c08 in main (argc=1, argv=0x7bff014c) at scp.c:335