From 4d5456c7de108e17603a0920c4d15bca87244921 Mon Sep 17 00:00:00 2001 From: "djm@openbsd.org" Date: Wed, 25 Oct 2017 00:21:37 +0000 Subject: upstream commit transfer ownership of stdout to the session channel by dup2'ing /dev/null to fd 1. This allows propagation of remote stdout close to the local side; reported by David Newall, ok markus@ Upstream-ID: 8d9ac18a11d89e6b0415f0cbf67b928ac67f0e79 --- ssh.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) diff --git a/ssh.c b/ssh.c index 74056985b..ae468d286 100644 --- a/ssh.c +++ b/ssh.c @@ -1,4 +1,4 @@ -/* $OpenBSD: ssh.c,v 1.466 2017/10/23 05:08:00 djm Exp $ */ +/* $OpenBSD: ssh.c,v 1.467 2017/10/25 00:21:37 djm Exp $ */ /* * Author: Tatu Ylonen * Copyright (c) 1995 Tatu Ylonen , Espoo, Finland @@ -1817,7 +1817,7 @@ ssh_session2_open(struct ssh *ssh) static int ssh_session2(struct ssh *ssh, struct passwd *pw) { - int id = -1; + int devnull, id = -1; char *cp, *tun_fwd_ifname = NULL; /* XXX should be pre-session */ @@ -1900,6 +1900,20 @@ ssh_session2(struct ssh *ssh, struct passwd *pw) options.permit_local_command) ssh_local_cmd(options.local_command); + /* + * stdout is now owned by the session channel; clobber it here + * so future channel closes are propagated to the local fd. + * NB. this can only happen after LocalCommand has completed, + * as it may want to write to stdout. + */ + if ((devnull = open(_PATH_DEVNULL, O_WRONLY)) == -1) + error("%s: open %s: %s", __func__, + _PATH_DEVNULL, strerror(errno)); + if (dup2(devnull, STDOUT_FILENO) < 0) + fatal("%s: dup2() stdout failed", __func__); + if (devnull > STDERR_FILENO) + close(devnull); + /* * If requested and we are not interested in replies to remote * forwarding requests, then let ssh continue in the background. -- cgit v1.2.3