This one is common to the TCPv4 and UDPv4 code, it retrieves the
destination address of a socket, taking care of the possiblity that for
an incoming connection the traffic was possibly redirected. The TCP and
UDP definitions were updated to rely on it and remove duplicated code.
The new file sock.c will contain generic code for standard sockets
relying on file descriptors. We currently have way too much duplication
between proto_uxst, proto_tcp, proto_sockpair and proto_udp.
For now only get_src, get_dst and sock_create_server_socket were moved,
and are used where appropriate.
This patch introduce proto_udp.c targeting a further support of
log forwarding feature.
This code was originally produced by Frederic Lecaille working on
QUIC support and only minimal requirements for syslog support
have been merged.
The set of files proto_udp.{c,h} were misleadingly named, as they do not
provide anything related to the UDP protocol but to datagram handling
instead, since currently all UDP processing is hard-coded where it's used
(dns, logs). They are to UDP what connection.{c,h} are to proto_tcp. This
was causing confusion about how to insert UDP socket management code,
so let's rename them right now to dgram.{c,h} which more accurately
matches what's inside since every function and type is already prefixed
with "dgram_".
