upstream: Add BindInterface ssh_config directive and -B

command-line argument to ssh(1) that directs it to bind its outgoing
connection to the address of the specified network interface.

BindInterface prefers to use addresses that aren't loopback or link-
local, but will fall back to those if no other addresses of the
required family are available on that interface.

Based on patch by Mike Manning in bz#2820, ok dtucker@

OpenBSD-Commit-ID: c5064d285c2851f773dd736a2c342aa384fbf713

1 files changed, 9 insertions, 2 deletions

diff --git a/ssh.1 b/ssh.1
index 9de2a11bd..d754b3a41 100644
--- a/ssh.1
+++ b/ssh.1
@@ -33,8 +33,8 @@
 .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 .\"
-.\" $OpenBSD: ssh.1,v 1.389 2017/11/03 02:29:17 djm Exp $
-.Dd $Mdocdate: November 3 2017 $
+.\" $OpenBSD: ssh.1,v 1.390 2018/02/23 02:34:33 djm Exp $
+.Dd $Mdocdate: February 23 2018 $
 .Dt SSH 1
 .Os
 .Sh NAME
@@ -43,6 +43,7 @@
 .Sh SYNOPSIS
 .Nm ssh
 .Op Fl 46AaCfGgKkMNnqsTtVvXxYy
+.Op Fl B Ar bind_interface
 .Op Fl b Ar bind_address
 .Op Fl c Ar cipher_spec
 .Op Fl D Oo Ar bind_address : Oc Ns Ar port
@@ -124,6 +125,12 @@ authenticate using the identities loaded into the agent.
 .It Fl a
 Disables forwarding of the authentication agent connection.
 .Pp
+.It Fl B Ar interface
+Bind to the address of
+.Ar interface
+before attempting to connect to the destination host.
+This is only useful on systems with more than one address.
+.Pp
 .It Fl b Ar bind_address
 Use
 .Ar bind_address