hang on exit - bug or no bug?

Markus Friedl markus at openbsd.org
Sat Oct 6 01:39:08 EST 2001

On Fri, Oct 05, 2001 at 11:06:01AM -0400, Nicolas Williams wrote:
> I can certainly confirm, from experience, that, on Solaris,
> rsh host command&
> hangs if "command" keeps its stdio open. Rlogin is what others are
> saying doesn't do this, but, so what?
> As Lee Eakin explained yesterday, there's things SSH does that RLOGIN
> doesn't, such as agent forwarding, X forwarding, port forwarding, all
> of which may or may not be needed by that background command that's
> still holding its stdio open.

the hang-on-exit problem is not related to forwarding.

> Perhaps there should be an option, that causes SSHD to exit when its
> child exits and the session was a TTY session, and to hell with grand-
> children's stdio. But the conservative behaviour needs to be available
> too.

perhaps it's acceptable to discard data for sessions with ttys,
but i'm not sure yet.


        if (c->ostate != CHAN_OUTPUT_CLOSED)
+	if (s->ttyfd != -1 && option.discard && c->istate == CHAN_INPUT_OPEN)
+		chan_read_failed(c);
        s->chanid = -1;

should help.


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