- dtucker@cvs.openbsd.org 2010/01/11 01:39:46
[ssh_config channels.c ssh.1 channels.h ssh.c]
Add a 'netcat mode' (ssh -W). This connects stdio on the client to a
single port forward on the server. This allows, for example, using ssh as
a ProxyCommand to route connections via intermediate servers.
bz #1618, man page help from jmc@, ok markus@
diff --git a/ssh.c b/ssh.c
index ee30e2b..b86a764 100644
--- a/ssh.c
+++ b/ssh.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh.c,v 1.330 2010/01/09 23:04:13 dtucker Exp $ */
+/* $OpenBSD: ssh.c,v 1.331 2010/01/11 01:39:46 dtucker Exp $ */
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -133,6 +133,10 @@
*/
int fork_after_authentication_flag = 0;
+/* forward stdio to remote host and port */
+char *stdio_forward_host = NULL;
+int stdio_forward_port = 0;
+
/*
* General data structure for command line options and options configurable
* in configuration files. See readconf.h.
@@ -186,7 +190,8 @@
" [-i identity_file] [-L [bind_address:]port:host:hostport]\n"
" [-l login_name] [-m mac_spec] [-O ctl_cmd] [-o option] [-p port]\n"
" [-R [bind_address:]port:host:hostport] [-S ctl_path]\n"
-" [-w local_tun[:remote_tun]] [user@]hostname [command]\n"
+" [-W host:port] [-w local_tun[:remote_tun]]\n"
+" [user@]hostname [command]\n"
);
exit(255);
}
@@ -276,7 +281,7 @@
again:
while ((opt = getopt(ac, av, "1246ab:c:e:fgi:kl:m:no:p:qstvx"
- "ACD:F:I:KL:MNO:PR:S:TVw:XYy")) != -1) {
+ "ACD:F:I:KL:MNO:PR:S:TVw:W:XYy")) != -1) {
switch (opt) {
case '1':
options.protocol = SSH_PROTO_1;
@@ -389,6 +394,22 @@
exit(255);
}
break;
+ case 'W':
+ if (parse_forward(&fwd, optarg, 1, 0)) {
+ stdio_forward_host = fwd.listen_host;
+ stdio_forward_port = fwd.listen_port;
+ xfree(fwd.connect_host);
+ } else {
+ fprintf(stderr,
+ "Bad stdio forwarding specification '%s'\n",
+ optarg);
+ exit(255);
+ }
+ no_tty_flag = 1;
+ no_shell_flag = 1;
+ options.clear_forwardings = 1;
+ options.exit_on_forward_failure = 1;
+ break;
case 'q':
options.log_level = SYSLOG_LEVEL_QUIET;
break;
@@ -871,11 +892,41 @@
}
static void
+client_cleanup_stdio_fwd(int id, void *arg)
+{
+ debug("stdio forwarding: done");
+ cleanup_exit(0);
+}
+
+static int
+client_setup_stdio_fwd(const char *host_to_connect, u_short port_to_connect)
+{
+ Channel *c;
+
+ debug3("client_setup_stdio_fwd %s:%d", host_to_connect,
+ port_to_connect);
+ if ((c = channel_connect_stdio_fwd(host_to_connect, port_to_connect))
+ == NULL)
+ return 0;
+ channel_register_cleanup(c->self, client_cleanup_stdio_fwd, 0);
+ return 1;
+}
+
+static void
ssh_init_forwarding(void)
{
int success = 0;
int i;
+ if (stdio_forward_host != NULL) {
+ if (!compat20) {
+ fatal("stdio forwarding require Protocol 2");
+ }
+ if (!client_setup_stdio_fwd(stdio_forward_host,
+ stdio_forward_port))
+ fatal("Failed to connect in stdio forward mode.");
+ }
+
/* Initiate local TCP/IP port forwardings. */
for (i = 0; i < options.num_local_forwards; i++) {
debug("Local connections to %.200s:%d forwarded to remote "