bgp: support next_hop_self

Support next_hop_self.
BGPSpeaker can replace a path's next_hop address with its own address
when it sends the path to iBGP peer.

Signed-off-by: Hiroshi Yokoi <yokoi.hiroshi@po.ntts.co.jp>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
oxm_fields: Add a comment

Signed-off-by: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
ofproto_v1_3_parser: Handle experimenter OXMs in TableFeatures

Signed-off-by: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
ofproto_v1_4_parser: Handle experimenter OXMs in TableFeatures

Signed-off-by: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
of12/3: support setting the oxm_value to OFPVID_NONE

In openflow spec 1.2 and 1.3.4, in order to match only packets without a VLAN tag,
the value of OFPXMT_OFB_VLAN_VID must be set to OFPVID_NONE (0x0000).
Old API of ofproto_v1_2/3_parser is now enabled to setting the oxm_value to OFPVID_NONE(0x0000) as follows:

e.g.)
    match = ofproto_v1_2_parser.OFPMatch()
    match.set_vlan_vid_none()

Signed-off-by: Minoru TAKAHASHI <takahashi.minoru7@gmail.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
test: add unittests for of1.3 parser

Signed-off-by: Minoru TAKAHASHI <takahashi.minoru7@gmail.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
ofctl_v1_0/2/3: check lock timeout by lock.is_set().

send_stats_request never catches hub.Timeout exception because it
has been caught by the event wait function itself.

Signed-off-by: Wei-Li Tang <alextwl@xinguard.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
packet lib: add BFD support.

Signed-off-by: Wei-Li Tang <alextwl@xinguard.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
unit test for lib.packet.bfd

Signed-off-by: Wei-Li Tang <alextwl@xinguard.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
lib: add IPv4 single hop BFD (RFC5881) support.

Signed-off-by: Wei-Li Tang <alextwl@xinguard.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
doc: add lib.packet.bfd classes to library_packet_ref.

Signed-off-by: Wei-Li Tang <alextwl@xinguard.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
bfdlib: follow TTL/hop limit in RFC5881 explicitly.

Signed-off-by: Wei-Li Tang <alextwl@xinguard.com>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>