upstream commit

Add a sshd_config DisableForwaring option that disables
X11, agent, TCP, tunnel and Unix domain socket forwarding, as well as
anything else we might implement in the future.

This, like the 'restrict' authorized_keys flag, is intended to be a
simple and future-proof way of restricting an account. Suggested as
a complement to 'restrict' by Jann Horn; ok markus@

Upstream-ID: 203803f66e533a474086b38a59ceb4cf2410fcf7

1 files changed, 5 insertions, 5 deletions

diff --git a/serverloop.c b/serverloop.c
index 4a9a16d41..955f5cc91 100644
--- a/serverloop.c
+++ b/serverloop.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: serverloop.c,v 1.187 2016/10/23 22:04:05 dtucker Exp $ */
+/* $OpenBSD: serverloop.c,v 1.188 2016/11/30 03:00:05 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -447,7 +447,7 @@ server_request_direct_tcpip(void)
 
         /* XXX fine grained permissions */
         if ((options.allow_tcp_forwarding & FORWARD_LOCAL) != 0 &&
-            !no_port_forwarding_flag) {
+            !no_port_forwarding_flag && !options.disable_forwarding) {
                 c = channel_connect_to_port(target, target_port,
                     "direct-tcpip", "direct-tcpip");
         } else {
@@ -479,7 +479,7 @@ server_request_direct_streamlocal(void)
 
         /* XXX fine grained permissions */
         if ((options.allow_streamlocal_forwarding & FORWARD_LOCAL) != 0 &&
-            !no_port_forwarding_flag) {
+            !no_port_forwarding_flag && !options.disable_forwarding) {
                 c = channel_connect_to_path(target,
                     "direct-streamlocal@openssh.com", "direct-streamlocal");
         } else {
@@ -722,7 +722,7 @@ server_input_global_request(int type, u_int32_t seq, void *ctxt)
 
                 /* check permissions */
                 if ((options.allow_tcp_forwarding & FORWARD_REMOTE) == 0 ||
-                    no_port_forwarding_flag ||
+                    no_port_forwarding_flag || options.disable_forwarding ||
                     (!want_reply && fwd.listen_port == 0) ||
                     (fwd.listen_port != 0 &&
                      !bind_permitted(fwd.listen_port, pw->pw_uid))) {
@@ -760,7 +760,7 @@ server_input_global_request(int type, u_int32_t seq, void *ctxt)
 
                 /* check permissions */
                 if ((options.allow_streamlocal_forwarding & FORWARD_REMOTE) == 0
-                    || no_port_forwarding_flag) {
+                    || no_port_forwarding_flag || options.disable_forwarding) {
                         success = 0;
                         packet_send_debug("Server has disabled port forwarding.");
                 } else {