warn when the user specifies a ForwardAgent path that does not exist

and exit if ExitOnForwardFailure is set; bz3264

diff --git a/usr.bin/ssh/ssh.c b/usr.bin/ssh/ssh.c
index 448934d..4533204 100644 (file)
--- a/usr.bin/ssh/ssh.c
+++ b/usr.bin/ssh/ssh.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh.c,v 1.551 2021/02/15 20:43:15 markus Exp $ */
+/* $OpenBSD: ssh.c,v 1.552 2021/02/23 00:05:31 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -1398,6 +1398,12 @@ main(int ac, char **av)
                free(p);
                free(options.forward_agent_sock_path);
                options.forward_agent_sock_path = cp;
+               if (stat(options.forward_agent_sock_path, &st) != 0) {
+                       error("Cannot forward agent socket path \"%s\": %s",
+                           options.forward_agent_sock_path, strerror(errno));
+                       if (options.exit_on_forward_failure)
+                               cleanup_exit(255);
+               }
        }
 
        if (options.num_system_hostfiles > 0 &&