udp: Re-use fixed bound sockets for packet forwarding when possible

When we look up udp_splice_to_ns[v6][src].target_sock in
udp_sock_handler_splice, all we really require of the socket is that it
be bound to port src in the pasta guest namespace.  Similarly for
udp_splice_to_init but bound in the init namespace.

Usually these sockets are created temporarily by udp_splice_connect() and
cleaned up by udp_timer().  However, depending on the -u and -U options its
possible we have a permanent socket bound to the relevant port created by
udp_sock_init().  If such a socket exists, we could use it instead of
creating a temporary one.  In fact we *must* use it, because we'll fail
trying to bind() a temporary one to the same port.

So allow this, store permanently bound sockets into udp_splice_to_{ns,init}
in udp_sock_init().  These won't get incorrectly removed by the timer
because we don't put a corresponding entry in the udp_act[] structure
which directs the timer what to clean up.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

0 files changed, 0 insertions, 0 deletions