Re: [PATCH] pasta: fix tcp port forwarding in auto mode

[Stefano Brivio <sbrivio@redhat.com>]

Thanks for the patch!

On Mon, 20 Mar 2023 19:10:34 +0100
Paul Holzinger <pholzing@redhat.com> wrote:

> The logic in tcp_timer() was inverted. fwd_out should expose the host
> ports in the ns. Therfore it must read the ports on the host and then
> bind them in the netns. The same for fwd_in which checks ports in the
> ns and then exposes them on the host.
> 
> Note that this only fixes tcp ports, udp does not seems to work at all
> right now with the auto mode.

Note that for UDP there's no periodic scan, "auto" just checks bound
ports when pasta starts:

       -u, --udp-ports spec
              Configure UDP port forwarding to namespace. spec is as described
              for TCP above, and the list of ports is derived  from  listening
              sockets   reported  by  /proc/net/udp  and  /proc/net/udp6,  see
              proc(5), when pasta starts (not periodically).

> Signed-off-by: Paul Holzinger <pholzing@redhat.com>

Fixes: 1128fa03fe73 ("Improve types and names for port forwarding configuration")

(I'll add that tag).

The patch itself looks good to me. I'm now looking at other parts
(tcp_sock_init()) where we seem to have the same kind of swap.

Unfortunately this is only covered by the Podman demo as a test, which
has been disabled for a while now:

  https://bugs.passt.top/show_bug.cgi?id=29

and as David is meanwhile working to improve the test framework, we can
probably wait a bit to introduce a new test. Meanwhile I'll check this
part manually on related changes.

-- 
Stefano