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>