upstream commit

Expose devices allocated for tun/tap forwarding.

At the client, the device may be obtained from a new %T expansion
for LocalCommand.

At the server, the allocated devices will be listed in a
SSH_TUNNEL variable exposed to the environment of any user sessions
started after the tunnel forwarding was established.

ok markus

Upstream-ID: e61e53f8ae80566e9ddc0d67a5df5bdf2f3c9f9e

1 files changed, 7 insertions, 5 deletions

diff --git a/clientloop.c b/clientloop.c
index 791d336e3..46ede4f0e 100644
--- a/clientloop.c
+++ b/clientloop.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: clientloop.c,v 1.305 2017/09/19 04:24:22 djm Exp $ */
+/* $OpenBSD: clientloop.c,v 1.306 2017/10/23 05:08:00 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -1601,12 +1601,13 @@ client_request_agent(struct ssh *ssh, const char *request_type, int rchan)
         return c;
 }
 
-int
+char *
 client_request_tun_fwd(struct ssh *ssh, int tun_mode,
     int local_tun, int remote_tun)
 {
         Channel *c;
         int fd;
+        char *ifname = NULL;
 
         if (tun_mode == SSH_TUNMODE_NO)
                 return 0;
@@ -1614,10 +1615,11 @@ client_request_tun_fwd(struct ssh *ssh, int tun_mode,
         debug("Requesting tun unit %d in mode %d", local_tun, tun_mode);
 
         /* Open local tunnel device */
-        if ((fd = tun_open(local_tun, tun_mode)) == -1) {
+        if ((fd = tun_open(local_tun, tun_mode, &ifname)) == -1) {
                 error("Tunnel device open failed.");
-                return -1;
+                return NULL;
         }
+        debug("Tunnel forwarding using interface %s", ifname);
 
         c = channel_new(ssh, "tun", SSH_CHANNEL_OPENING, fd, fd, -1,
             CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, "tun", 1);
@@ -1638,7 +1640,7 @@ client_request_tun_fwd(struct ssh *ssh, int tun_mode,
         packet_put_int(remote_tun);
         packet_send();
 
-        return 0;
+        return ifname;
 }
 
 /* XXXX move to generic input handler */