ofproto/xlate: Add xlate_lookup_ofproto().

"xlate_receive" did not tell much about what it is used for.  We have
two users of it that only want the ofproto and the OF port number, use the
new xlate_lookup_ofproto() for those.

Fix the comments of xlate_receive() as we no longer change the flow.

Also, the helper ofproto_dpif_contains_flow() seemed ill-named, so this
path removes it and uses xlate_lookup_ofproto() directly.

Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>
ofproto-dpif-upcall: Remove struct upcall netflow member.

The netflow member was not used for anything, so it can be removed.

Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>
ofproto-dpif-xlate: Do not take references in xlate_receive().

xlate configuration (via xcfg) is already holding the references, so
the callers of xlate_receive() can safely use the returned pointers
upto the point when they quiesce.  If the objects are needed for
longer term, the callers can take additional references themselves.

Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>
ofproto-dpif-xlate: Rename xlate_receive() as xlate_lookup().

Seems better as we no longer modify the flow.

Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>