Handle ARP packet with NULL src ip as Gratuitous ARP

[Divakar Dharanalakota]

As per RFC 5227 following needs to be satisfied

 An ARP request/response packet with zero source IP address need to be treated as Gratuitous ARP packet. This is called ARP Probe and DHCP clients/servers typically use this to identify duplicate IPV4 address allocation.

2) A gratuitous ARP can also be ARP reply.

[OpenContrail Admin (ci-admin-f)]

Review in progress for https://review.opencontrail.org/14955
Submitter: Hari Prasad Killi (<email address hidden>)

[OpenContrail Admin (ci-admin-f)]

Review in progress for https://review.opencontrail.org/14956
Submitter: Hari Prasad Killi (<email address hidden>)

[OpenContrail Admin (ci-admin-f)]

Reviewed: https://review.opencontrail.org/14955
Committed: http://github.org/Juniper/contrail-vrouter/commit/36ceb42cdc4e9020660de3fc3c475690c5849496
Submitter: Zuul
Branch: R2.20

commit 36ceb42cdc4e9020660de3fc3c475690c5849496
Author: Hari <email address hidden>
Date: Sat Nov 7 07:57:45 2015 +0530

Treat ARP pkt with zero source IP as Gratuitous ARP

As per RFC 5227, when ARP packet is received with zero source IP, this
needs to be treated as ARP PRobe. In Vrouter case, it should not be
treatd as regular ARP request and flooded to complete VN, so that VM/BMS
treats this like ARP probe and take appropriate action. Vrouter treating
this as ARP request results in senidng ARP response with stiched/Proxied
MAC.

Committing on behalf of Divakar.

Change-Id: Ia89e0d99b7b8895243e5707c8f67dc78265db8a9
closes-bug: #1513793

[OpenContrail Admin (ci-admin-f)]

Reviewed: https://review.opencontrail.org/14956
Committed: http://github.org/Juniper/contrail-vrouter/commit/5c6390a7ecba78ea91dfbf3c1d6ab394c51aa281
Submitter: Zuul
Branch: R2.21.x

commit 5c6390a7ecba78ea91dfbf3c1d6ab394c51aa281
Author: Hari <email address hidden>
Date: Sat Nov 7 08:01:29 2015 +0530

Treat ARP pkt with zero source IP as Gratuitous ARP

As per RFC 5227, when ARP packet is received with zero source IP, this
needs to be treated as ARP PRobe. In Vrouter case, it should not be
treatd as regular ARP request and flooded to complete VN, so that VM/BMS
treats this like ARP probe and take appropriate action. Vrouter treating
this as ARP request results in senidng ARP response with stiched/Proxied
MAC.

Committing on Divakar's behalf.

Change-Id: I7d9943054882c8167fb29b2e5c93089591962d41
closes-bug: #1513793

[OpenContrail Admin (ci-admin-f)]

Review in progress for https://review.opencontrail.org/14975
Submitter: Hari Prasad Killi (<email address hidden>)

[OpenContrail Admin (ci-admin-f)]

Reviewed: https://review.opencontrail.org/14975
Committed: http://github.org/Juniper/contrail-vrouter/commit/b9be67ef2e44c551d88a0ef5e875d4bbf165579b
Submitter: Zuul
Branch: master

commit b9be67ef2e44c551d88a0ef5e875d4bbf165579b
Author: Hari <email address hidden>
Date: Mon Nov 9 14:18:50 2015 +0530

Treat ARP pkt with zero source IP as Gratuitous ARP

As per RFC 5227, when ARP packet is received with zero source IP, this
needs to be treated as ARP PRobe. In Vrouter case, it should not be
treatd as regular ARP request and flooded to complete VN, so that VM/BMS
treats this like ARP probe and take appropriate action. Vrouter treating
this as ARP request results in senidng ARP response with stiched/Proxied
MAC.

Committing on Divakar's behalf.

Change-Id: Ib70e7c81ce6dcd2d5126fc43316ef9e0b6ef2592
closes-bug: #1513793