some flows stuck in vrouter forever

Even without fuzzed scapy traffic, long term hping port-scan tests also seem to be resulting in this :

  4186620<=>3691752 10.1.1.64:22 6 (1)
                         10.1.1.17:6202
(Gen: 156, K(nh):63, Action:F, Flags:, TCP:Sr, S(nh):63, Stats:0/0, SPort 55361)

  4187784<=>2991652 10.1.1.76:22 6 (1)
                         10.1.1.59:6091
(Gen: 126, K(nh):78, Action:D(NoDstRt), Flags:, TCP:Sr, S(nh):2, Stats:0/0, SPort 50050)

  4189732<=>4004520 10.1.1.76:22 6 (1)
                         10.1.1.61:3706
(Gen: 113, K(nh):58, Action:F, Flags:, TCP:Sr, S(nh):51, Stats:0/0, SPort 62374)

  4190812<=>1732228 10.1.1.76:22 6 (1)
                         10.1.1.59:4999
(Gen: 114, K(nh):78, Action:F, Flags:, TCP:Sr, S(nh):51, Stats:0/0, SPort 54255)

  4192020<=>2778592 10.1.1.76:22 6 (1)
                         10.1.1.61:4751
(Gen: 124, K(nh):58, Action:D(NoDstRt), Flags:, TCP:Sr, S(nh):2, Stats:0/0, SPort 54154)

  4192500<=>3842844 10.1.1.79:22 6 (1)
                         10.1.1.60:4311
(Gen: 108, K(nh):16, Action:F, Flags:, TCP:Sr, S(nh):51, Stats:0/0, SPort 61081)

  4196424<=>3064736 10.1.1.59:22 6 (1)
                         10.1.1.20:5430
(Gen: 67, K(nh):78, Action:F, Flags:, TCP:Sr, S(nh):78, Stats:0/0, SPort 56493)

  4199000<=>2231804 10.1.1.94:22 6 (1)
                         10.1.1.62:5942
(Gen: 125, K(nh):83, Action:F, Flags:, TCP:Sr, S(nh):53, Stats:0/0, SPort 64109)

issue happened where delete message for reverse flow was not sent if flow was deleted before getting an Ack with index from vrouter.

Review in progress for https://review.opencontrail.org/19437
Submitter: Prabhjot Singh Sethi (<email address hidden>)

Review in progress for https://review.opencontrail.org/19438
Submitter: Prabhjot Singh Sethi (<email address hidden>)

Reviewed: https://review.opencontrail.org/19438
Committed: http://github.org/Juniper/contrail-controller/commit/26e0c9e060ff12b86cf48b179d60091d87fc11be
Submitter: Zuul
Branch: R3.0

commit 26e0c9e060ff12b86cf48b179d60091d87fc11be
Author: Prabhjot Singh Sethi <email address hidden>
Date: Tue Apr 19 15:48:48 2016 +0530

Fix to delete flow from vrouter appropriately

Issue:
------
If a delete is triggered for reverse flow before getting
flow handle allocated, it was trying to acquire index with
index and gen_id info from flow entry instead of KSyncEntry
Since the flow is is already marked deleted or reused, its
index and gen id will not match with the one allocated to
KSyncEntry, this results in false evaluation as if the flow
is already Evicted, resulting in skipping Delete Message to
Vrouter

Fix:
----
Acquire Index using the KSyncEntry hash id and gen id, while
Ksync entry is already deleted.
Added Event Log for message skip for evicted flow

Closes-Bug: 1569967
Change-Id: Ib3f761d05e3d522905b012184dc8528bb0d5eba3
(cherry picked from commit c6bc5d93bc28dc20ac3e8cfb75405fd58f74247e)

Reviewed: https://review.opencontrail.org/19437
Committed: http://github.org/Juniper/contrail-controller/commit/c6bc5d93bc28dc20ac3e8cfb75405fd58f74247e
Submitter: Zuul
Branch: master

commit c6bc5d93bc28dc20ac3e8cfb75405fd58f74247e
Author: Prabhjot Singh Sethi <email address hidden>
Date: Tue Apr 19 15:48:48 2016 +0530

Fix to delete flow from vrouter appropriately

Issue:
------
If a delete is triggered for reverse flow before getting
flow handle allocated, it was trying to acquire index with
index and gen_id info from flow entry instead of KSyncEntry
Since the flow is is already marked deleted or reused, its
index and gen id will not match with the one allocated to
KSyncEntry, this results in false evaluation as if the flow
is already Evicted, resulting in skipping Delete Message to
Vrouter

Fix:
----
Acquire Index using the KSyncEntry hash id and gen id, while
Ksync entry is already deleted.
Added Event Log for message skip for evicted flow

Closes-Bug: 1569967
Change-Id: Ib3f761d05e3d522905b012184dc8528bb0d5eba3