bz#1232: ensure that any specified LocalCommand is executed after the

tunnel device is opened. Also, make failures to open a tunnel device
fatal when ExitOnForwardFailure is active.
Reported by h.goebel AT goebel-consult.de; ok dtucker markus reyk deraadt

3 files changed, 56 insertions, 26 deletions

diff --git a/usr.bin/ssh/clientloop.c b/usr.bin/ssh/clientloop.c
index 775cb48b051..3948c89cc4b 100644
--- a/usr.bin/ssh/clientloop.c
+++ b/usr.bin/ssh/clientloop.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: clientloop.c,v 1.179 2007/03/20 03:56:12 tedu Exp $ */
+/* $OpenBSD: clientloop.c,v 1.180 2007/08/07 07:32:53 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -1765,6 +1765,44 @@ client_request_agent(const char *request_type, int rchan)
 	return c;
 }
 
+int
+client_request_tun_fwd(int tun_mode, int local_tun, int remote_tun)
+{
+	Channel *c;
+	int fd;
+
+	if (tun_mode == SSH_TUNMODE_NO)
+		return 0;
+
+	if (!compat20) {
+		error("Tunnel forwarding is not support for protocol 1");
+		return -1;
+	}
+
+	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) {
+		error("Tunnel device open failed.");
+		return -1;
+	}
+
+	c = channel_new("tun", SSH_CHANNEL_OPENING, fd, fd, -1,
+	    CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 0, "tun", 1);
+	c->datagram = 1;
+
+	packet_start(SSH2_MSG_CHANNEL_OPEN);
+	packet_put_cstring("tun@openssh.com");
+	packet_put_int(c->self);
+	packet_put_int(c->local_window_max);
+	packet_put_int(c->local_maxpacket);
+	packet_put_int(tun_mode);
+	packet_put_int(remote_tun);
+	packet_send();
+
+	return 0;
+}
+
 /* XXXX move to generic input handler */
 static void
 client_input_channel_open(int type, u_int32_t seq, void *ctxt)
diff --git a/usr.bin/ssh/clientloop.h b/usr.bin/ssh/clientloop.h
index beec62f70b0..c7d2233d03a 100644
--- a/usr.bin/ssh/clientloop.h
+++ b/usr.bin/ssh/clientloop.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: clientloop.h,v 1.16 2006/03/25 22:22:42 djm Exp $ */
+/* $OpenBSD: clientloop.h,v 1.17 2007/08/07 07:32:53 djm Exp $ */
 
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
@@ -44,6 +44,7 @@ void	 client_x11_get_proto(const char *, const char *, u_int,
 void	 client_global_request_reply_fwd(int, u_int32_t, void *);
 void	 client_session2_setup(int, int, int, const char *, struct termios *,
 	    int, Buffer *, char **, dispatch_fn *);
+int	 client_request_tun_fwd(int, int, int);
 
 /* Multiplexing protocol version */
 #define SSHMUX_VER			1
diff --git a/usr.bin/ssh/ssh.c b/usr.bin/ssh/ssh.c
index ba269aa4be8..7f656522e95 100644
--- a/usr.bin/ssh/ssh.c
+++ b/usr.bin/ssh/ssh.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh.c,v 1.300 2007/06/14 22:48:05 djm Exp $ */
+/* $OpenBSD: ssh.c,v 1.301 2007/08/07 07:32:53 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -838,6 +838,17 @@ ssh_init_forwarding(void)
 				    "forwarding.");
 		}
 	}
+
+	/* Initiate tunnel forwarding. */
+	if (options.tun_open != SSH_TUNMODE_NO) {
+		if (client_request_tun_fwd(options.tun_open,
+		    options.tun_local, options.tun_remote) == -1) {
+			if (options.exit_on_forward_failure)
+				fatal("Could not request tunnel forwarding.");
+			else
+				error("Could not request tunnel forwarding.");
+		}
+	}			
 }
 
 static void
@@ -1099,28 +1110,6 @@ ssh_session2_setup(int id, void *arg)
 		packet_send();
 	}
 
-	if (options.tun_open != SSH_TUNMODE_NO) {
-		Channel *c;
-		int fd;
-
-		debug("Requesting tun.");
-		if ((fd = tun_open(options.tun_local,
-		    options.tun_open)) >= 0) {
-			c = channel_new("tun", SSH_CHANNEL_OPENING, fd, fd, -1,
-			    CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
-			    0, "tun", 1);
-			c->datagram = 1;
-			packet_start(SSH2_MSG_CHANNEL_OPEN);
-			packet_put_cstring("tun@openssh.com");
-			packet_put_int(c->self);
-			packet_put_int(c->local_window_max);
-			packet_put_int(c->local_maxpacket);
-			packet_put_int(options.tun_open);
-			packet_put_int(options.tun_remote);
-			packet_send();
-		}
-	}
-
 	client_session2_setup(id, tty_flag, subsystem_flag, getenv("TERM"),
 	    NULL, fileno(stdin), &command, environ, &ssh_subsystem_reply);
 
@@ -1180,7 +1169,6 @@ ssh_session2(void)
 
 	/* XXX should be pre-session */
 	ssh_init_forwarding();
-	ssh_control_listener();
 
 	if (!no_shell_flag || (datafellows & SSH_BUG_DUMMYCHAN))
 		id = ssh_session2_open();
@@ -1190,6 +1178,9 @@ ssh_session2(void)
 	    options.permit_local_command)
 		ssh_local_cmd(options.local_command);
 
+	/* Start listening for multiplex clients */
+	ssh_control_listener();
+
 	/* If requested, let ssh continue in the background. */
 	if (fork_after_authentication_flag)
 		if (daemon(1, 1) < 0)