meta-flow: Autogenerate mf_field data structures.

This is a first step toward improving the abstraction of OXM and NXM in the
tree.  As an immediate improvement, this commit removes all of the
definitions of the OXM and NXM constants from the top-level header files,
because they are no longer used anywhere.

Signed-off-by: Ben Pfaff <blp@nicira.com>
Acked-by: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Acked-by: Jarno Rajahalme <jrajahalme@nicira.com>
util: New function bitwise_scan().

This will acquire its first user in an upcoming commit.

This implementation is not optimized at all but it doesn't matter for the
purpose for which I intend to initially use it.

Signed-off-by: Ben Pfaff <blp@nicira.com>
Acked-by: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
ovs-ofctl: Encode cookies in OXM-compliant manner.

NXM/OXM are only supposed to put 1-bits in a value if the corresponding bit
in the mask is a 1-bit, but in the case of cookie matching, e.g.
    ovs-ofctl del-flows br0 cookie=0x3/0x1
ovs-ofctl would encode a bad OXM.  This fixes the problem.

(The test "ofproto - del flows based on cookie mask" in the OVS testsuite
tickles this bug.)

Signed-off-by: Ben Pfaff <blp@nicira.com>
Acked-by: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
nx-match: Move all knowledge of OXM/NXM here.

This improves the general abstraction of OXM/NXM by eliminating direct
knowledge of it from the meta-flow code and other places.

Some function renaming might be called for; for example, mf_oxm_header()
may not be the best name now that the function is implemented within
nx-match.  However, these renamings would make this commit larger and
harder to review, so I'm postponing them.

Signed-off-by: Ben Pfaff <blp@nicira.com>
Acked-by: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
ofp-actions: Better support OXM in Copy-Field action.

The OpenFlow 1.5 (draft) Copy-Field action has two OXM headers, one after
the other.  Until now, Open vSwitch has implemented these as a pair of
ovs_be32 members, which meant that only 32-bit OXM could be supported.  This
commit changes the implementation to use nx_pull_header(), which means that
in the future when that function supports 64-bit experimenter OXMs,
Copy-Field will automatically get that support too.

Signed-off-by: Ben Pfaff <blp@nicira.com>
Acked-by: YAMAMOTO Takashi <yamamoto@valinux.co.jp>