Debian Bug report logs - #313371
annoying "Killed by signal 1" message with ProxyCommand

Toggle useless messages

Message #5 received at submit@bugs.debian.org (full text, mbox, reply):

From: Sean Neakums <sneakums@zork.net>

To: submit@bugs.debian.org

Subject: annoying "Killed by signal 1" message with ProxyCommand

Date: Mon, 13 Jun 2005 11:35:38 +0100

Package: openssh-client
Version: 1:4.1p1-3

When using nc or socat to bounce connections to an ssh server via an
intermediary, "Killed by signal 1." is printed when I log out.
Signal 1 is SIGHUP.  This does not happen with ssh 1:3.8.1p1-8.sarge.4.

Example commands:

	ssh -o 'ProxyCommand ssh localhost socat - TCP4:%h:%p' localhost

	ssh -o 'ProxyCommand ssh localhost nc %h %p' localhost

The first 'localhost' is normally the intermediary host.

-- 
Dag vijandelijk luchtschip de huismeester is dood

Message #10 received at 313371@bugs.debian.org (full text, mbox, reply):

From: Peter Samuelson <peter@p12n.org>

To: 313371@bugs.debian.org

Subject: ssh: should not print "Killed by signal" messages at all

Date: Sat, 12 Nov 2005 02:26:22 -0600

[Message part 1 (text/plain, inline)]

I'll go one farther than the submitter of #313371 and claim that *all*
the "Killed by signal N" messages are unneeded.  Most Unix programs
don't print such messages; that's the shell's job.

The reason I care is that subversion can use a ssh pipe, and needs to
be able to kill the pipeline when it is done.  The comment in the
subversion source is illuminating:

  /* Arrange for the tunnel agent to get a SIGKILL on pool
   * cleanup.  This is a little extreme, but the alternatives
   * weren't working out:
   ...
   *   - Killing the tunnel agent with SIGTERM leads to unsightly
   *     stderr output from ssh.
   */

SIGKILL is, as the comment notes, "a little extreme".  For one thing,
if "ControlMaster auto" is in effect, ssh can't remove its socket file.

In my opinion, at least SIGTERM and SIGINT should not print a warning
to stderr.  SIGTERM is long-accepted way to kill something "just
because it's time for it to die now", and SIGINT is usually a keyboard
command, so in both cases the user should already know why subversion
is dying.  If she wants to hear more about it, she'll be running a
shell that will tell her about signal exit statuses.

It's more useful to warn on death-by-SIGFPE or death-by-SIGABRT or some
of those others, but I'd still argue that it isn't *necessary*.

--- clientloop.c~
+++ clientloop.c
@@ -1505,8 +1505,16 @@
 		exit_status = 0;
 	}
 
-	if (received_signal)
-		fatal("Killed by signal %d.", (int) received_signal);
+	/*
+	 * SIGTERM and SIGINT are usually done on purpose by the user; no
+	 * need to be noisy about getting them.  The extra noise is, for
+	 * one thing, annoying when ssh is run and killed noninteractively.
+	 */
+	if (received_signal) {
+		if (received_signal != SIGTERM && received_signal != SIGINT)
+			fatal("Killed by signal %d.", (int) received_signal);
+		cleanup_exit(received_signal + 128);
+	}
 
 	/*
 	 * In interactive mode (with pseudo tty) display a message indicating

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Message #17 received at 313371-close@bugs.debian.org (full text, mbox, reply):

From: Colin Watson <cjwatson@debian.org>

To: 313371-close@bugs.debian.org

Subject: Bug#313371: fixed in openssh 1:4.2p1-6

Date: Mon, 20 Feb 2006 09:17:26 -0800

Source: openssh
Source-Version: 1:4.2p1-6

We believe that the bug you reported is fixed in the latest version of
openssh, which is due to be installed in the Debian FTP archive:

openssh-client-udeb_4.2p1-6_powerpc.udeb
  to pool/main/o/openssh/openssh-client-udeb_4.2p1-6_powerpc.udeb
openssh-client_4.2p1-6_powerpc.deb
  to pool/main/o/openssh/openssh-client_4.2p1-6_powerpc.deb
openssh-server-udeb_4.2p1-6_powerpc.udeb
  to pool/main/o/openssh/openssh-server-udeb_4.2p1-6_powerpc.udeb
openssh-server_4.2p1-6_powerpc.deb
  to pool/main/o/openssh/openssh-server_4.2p1-6_powerpc.deb
openssh_4.2p1-6.diff.gz
  to pool/main/o/openssh/openssh_4.2p1-6.diff.gz
openssh_4.2p1-6.dsc
  to pool/main/o/openssh/openssh_4.2p1-6.dsc
ssh-askpass-gnome_4.2p1-6_powerpc.deb
  to pool/main/o/openssh/ssh-askpass-gnome_4.2p1-6_powerpc.deb
ssh_4.2p1-6_all.deb
  to pool/main/o/openssh/ssh_4.2p1-6_all.deb



A summary of the changes between this version and the previous one is
attached.

Thank you for reporting the bug, which will now be closed.  If you
have further comments please address them to 313371@bugs.debian.org,
and the maintainer will reopen the bug report if appropriate.

Debian distribution maintenance software
pp.
Colin Watson <cjwatson@debian.org> (supplier of updated openssh package)

(This message was generated automatically at their request; if you
believe that there is a problem with it please contact the archive
administrators by mailing ftpmaster@debian.org)


-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Format: 1.7
Date: Mon, 20 Feb 2006 16:50:55 +0000
Source: openssh
Binary: ssh-askpass-gnome openssh-client-udeb ssh openssh-server openssh-client openssh-server-udeb
Architecture: source powerpc all
Version: 1:4.2p1-6
Distribution: unstable
Urgency: low
Maintainer: Matthew Vernon <matthew@debian.org>
Changed-By: Colin Watson <cjwatson@debian.org>
Description: 
 openssh-client - Secure shell client, an rlogin/rsh/rcp replacement
 openssh-client-udeb - Secure shell client for the Debian installer (udeb)
 openssh-server - Secure shell server, an rshd replacement
 openssh-server-udeb - Secure shell server for the Debian installer (udeb)
 ssh        - Secure shell client and server (transitional package)
 ssh-askpass-gnome - under X, asks user for a passphrase for ssh-add
Closes: 313371 333133 341371
Changes: 
 openssh (1:4.2p1-6) unstable; urgency=low
 .
   * Sync default values of $PATH from shadow 1:4.0.12-6, adding /usr/bin/X11
     to the normal and superuser paths and /usr/games to the normal path.
   * When the client receives a signal, don't fatal() with "Killed by signal
     %d." (which produces unhelpful noise on stderr and causes confusion for
     users of some applications that wrap ssh); instead, generate a debug
     message and exit with the traditional status (closes: #313371).
   * debconf template translations:
     - Add Swedish (thanks, Daniel Nylander; closes: #333133).
     - Update Spanish (thanks, Javier Fernández-Sanguino Peña;
       closes: #341371).
     - Correct erroneously-changed Last-Translator headers in Greek and
       Spanish translations.
Files: 
 cddf91e9c77d026be4719aa1b2eb38bc 985 net standard openssh_4.2p1-6.dsc
 0301439133f6ca2a5f8f5dd65dcbe6a2 166033 net standard openssh_4.2p1-6.diff.gz
 3cb50433e8d97d551b1cdad1e1c74bf6 1056 net extra ssh_4.2p1-6_all.deb
 a697750c2de306ec197a67b41750d1ed 589766 net standard openssh-client_4.2p1-6_powerpc.deb
 5bd03be01555852cfc1053a1cade6cd4 226068 net optional openssh-server_4.2p1-6_powerpc.deb
 542bf3410fda84cb9a75c08c7fd9f0e7 86604 gnome optional ssh-askpass-gnome_4.2p1-6_powerpc.deb
 822ea7c20198099fac4c2e281cae083e 157538 debian-installer optional openssh-client-udeb_4.2p1-6_powerpc.udeb
 b7e84b6fb634f6f926d3c1ab8e89df9f 165276 debian-installer optional openssh-server-udeb_4.2p1-6_powerpc.udeb

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