Comment 26 for bug 1648696

Reviewed: https://review.opencontrail.org/29167
Committed: http://github.org/Juniper/contrail-controller/commit/a6ded5ee36fbb1cc204e759037fa5eee238cca1c
Submitter: Zuul (<email address hidden>)
Branch: R3.2

commit a6ded5ee36fbb1cc204e759037fa5eee238cca1c
Author: Praveen K V <email address hidden>
Date: Sat Dec 24 14:43:41 2016 +0530

Ensure flow-stickiness in case of ECMP with bridged forward flow and routed reverse flow

This is part of change needed to ensure flow-stickiness when forward flow
is bridged and reverse flow is routed. It has following parts,

Change to support ECMP Index management by VRouter

VRouter now manages the ECMP Index for a flow. It keeps tracks source
for a flow and updates the ECMP Index in reverse flow such that reverse
flow are sent to origin.

This commit supports ECMP Index management by VRouter. The key for
reverse flow can potentially depend on the ECMP Index used for forward
flow. Hence, Agent computes initial ECMP Index for forward flows still.
However, agent does not compute ECMP Index for reverse flow.

Re-organized the ECMP and RPF management mode in the process.

Re-organized UT code for ECMP and RPF checks

Pending:
1. Skip VRF assignment for bridged packets
2. Support Unrestricted Proxy-ARP on interface

Conflicts:
 src/vnsw/agent/pkt/pkt_handler.cc
 src/vnsw/agent/pkt/test/SConscript
 src/vnsw/agent/pkt/test/test_ecmp.cc
 src/vnsw/agent/pkt/test/test_ecmp_local.cc
 src/vnsw/agent/pkt/test/test_fip_dst_ecmp.cc
 src/vnsw/agent/pkt/test/test_pkt_util.cc
 src/vnsw/agent/pkt/test/test_pkt_util.h
 src/vnsw/agent/pkt/test/test_rpf_flow.cc
 src/vnsw/agent/test/test_cmn_util.h

Change-Id: Iff3ee337ef9721df3e91336960691dc2480a22bb
Partial-Bug: #1648696
Partial-Bug: #1645978