openssh unix dev - Oct 2009 - Patch to fix dynamic -R forwarding when not root

Hi!

Sorry if this has already been reported or even fixed, I didn't search
very thoroughly. Here's a patch to make dynamic -R remote port
allocation work even when not connecting as root. Without the patch I
got that "Server has disabled port forwarding." message visible in the
patch.

OpenSSH version I'm using is openssh-5.2p1, compiled from official
source package, configured without any configure options, on Ubuntu
Linux platform.

PS. If this patch isn't necessary, and I did something else wrong when
trying to 'ssh -R 0:localhost:22 user at remote', please let me know!


--- serverloop.c.original	2009-10-21 10:45:13.000000000 +0300
+++ serverloop.c	2009-10-21 10:53:09.000000000 +0300
@@ -1119,9 +1119,9 @@
 		if (!options.allow_tcp_forwarding ||
 		    no_port_forwarding_flag ||
 		    (!want_reply && listen_port == 0)
 #ifndef NO_IPPORT_RESERVED_CONCEPT
-		    || (listen_port < IPPORT_RESERVED && pw->pw_uid != 0)
+		    || (listen_port !=0 && listen_port < IPPORT_RESERVED
&& pw->pw_uid != 0)
 #endif
 		    ) {
 			success = 0;
 			packet_send_debug("Server has disabled port forwarding.");


-- 
Ari Hyttinen

And yes, it's indeed been fixed in 5.3p1. For some reason the mirror I
got the "latest" source from didn't yet have 5.3. So just ignore
this,
sorry for the noise.


2009/10/21 Ari Hyttinen <ari.hyttinen at
gmail.com>:
> Hi!
>
> Sorry if this has already been reported or even fixed, I didn't search
> very thoroughly. Here's a patch to make dynamic -R remote port
> allocation work even when not connecting as root. Without the patch I
> got that "Server has disabled port forwarding." message visible
in the
> patch.
>
> OpenSSH version I'm using is openssh-5.2p1, compiled from official
> source package, configured without any configure options, on Ubuntu
> Linux platform.
>
> PS. If this patch isn't necessary, and I did something else wrong when
> trying to 'ssh -R 0:localhost:22 user at remote', please let me
know!
>
>
> --- serverloop.c.original ? ? ? 2009-10-21 10:45:13.000000000 +0300
> +++ serverloop.c ? ? ? ?2009-10-21 10:53:09.000000000 +0300
> @@ -1119,9 +1119,9 @@
> ? ? ? ? ? ? ? ?if (!options.allow_tcp_forwarding ||
> ? ? ? ? ? ? ? ? ? ?no_port_forwarding_flag ||
> ? ? ? ? ? ? ? ? ? ?(!want_reply && listen_port == 0)
> ?#ifndef NO_IPPORT_RESERVED_CONCEPT
> - ? ? ? ? ? ? ? ? ? || (listen_port < IPPORT_RESERVED &&
pw->pw_uid != 0)
> + ? ? ? ? ? ? ? ? ? || (listen_port !=0 && listen_port <
IPPORT_RESERVED && pw->pw_uid != 0)
> ?#endif
> ? ? ? ? ? ? ? ? ? ?) {
> ? ? ? ? ? ? ? ? ? ? ? ?success = 0;
> ? ? ? ? ? ? ? ? ? ? ? ?packet_send_debug("Server has disabled port
forwarding.");
>
>
> --
> Ari Hyttinen
>