udp: Don't explicitly track originating socket for spliced "connections"

When we look up udp_splice_to_ns[][].orig_sock in udp_sock_handler_splice()
we're finding the socket on which the originating packet for the
"connection" was received on.  However, we don't specifically need this
socket to be the originating one - we just need one that's bound to the
the source port of this reply packet in the init namespace.  We can look
this up in udp_splice_to_init[v6][src].target_sock, whose defining
characteristic is exactly that.  The same applies with init and ns swapped.

In practice, of course, the port we locate this way will always be the
originating port, since we couldn't have started this "connection" if it
wasn't.

Change this, and we no longer need the @orig_sock field at all. That
leaves just @target_sock which we rename to simply @sock.  The whole
udp_splice_flow structure now more represents a single bound port than
a "flow" per se, so rename and recomment it accordingly.  Likewise the
udp_splice_to_{ns,init} names are now misleading, since the ports in
those maps are used in both directions.  Rename them to
udp_splice_{ns,init} indicating the location where the described
socket is bound.

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