Support for notification-triggered LLGR

[richard roberts]

LLGR is currently supported in Contrail.

However, in many cases BGP routers will send NOTIFICATION messages to handle error conditions, which will make the LLGR/BGP persistence strategies inoperative.

This LP is created to track the implementation of Notification message support for GR on Contrail.
as per https://tools.ietf.org/html/draft-ietf-idr-bgp-gr-notification-10.

[OpenContrail Admin (ci-admin-f)]

Review in progress for https://review.opencontrail.org/30862
Submitter: Ananth Suryanarayana (<email address hidden>)

[OpenContrail Admin (ci-admin-f)]

Reviewed: https://review.opencontrail.org/30862
Committed: http://github.com/Juniper/contrail-controller/commit/c45ed8bbbdb2bf008f22b45e04a49d377e26c43e
Submitter: Zuul (<email address hidden>)
Branch: master

commit c45ed8bbbdb2bf008f22b45e04a49d377e26c43e
Author: Ananth Suryanarayana <email address hidden>
Date: Thu Apr 27 15:34:46 2017 -0700

Add BGP Notification Flag support in GR

https://tools.ietf.org/html/draft-ietf-idr-bgp-gr-notification-10

Attempt GR Helper mode for all received notifications (and hold-timer expiry)
except HardReset and PeerDeconfigured.

Always send Notifications. NotificationFlag support has been in JUNOS already
for a while. Older versions of control-node already skips most of the
notifications received (and triggers GR helper mode)

Also fix a couple of nits found by cpplint

Closes-Bug: 1680047
Change-Id: Ic0462e9483dda8ee2f6c1be503bf1c120c3d6786

[OpenContrail Admin (ci-admin-f)]

Review in progress for https://review.opencontrail.org/30886
Submitter: Ananth Suryanarayana (<email address hidden>)

[OpenContrail Admin (ci-admin-f)]

Reviewed: https://review.opencontrail.org/30886
Committed: http://github.com/Juniper/contrail-controller/commit/c2cec615b01f946a8ea9f07737bf84684f1e43a7
Submitter: Zuul (<email address hidden>)
Branch: R3.2

commit c2cec615b01f946a8ea9f07737bf84684f1e43a7
Author: Ananth Suryanarayana <email address hidden>
Date: Thu Apr 27 15:34:46 2017 -0700

Add BGP Notification Flag support in GR

https://tools.ietf.org/html/draft-ietf-idr-bgp-gr-notification-10

Attempt GR Helper mode for all received notifications (and hold-timer expiry)
except HardReset and PeerDeconfigured.

Always send Notifications. NotificationFlag support has been in JUNOS already
for a while. Older versions of control-node already skips most of the
notifications received (and triggers GR helper mode)

Also fix a couple of nits found by cpplint

Closes-Bug: 1680047
Change-Id: Ic0462e9483dda8ee2f6c1be503bf1c120c3d6786
(cherry picked from commit c45ed8bbbdb2bf008f22b45e04a49d377e26c43e)

[OpenContrail Admin (ci-admin-f)]

Review in progress for https://review.opencontrail.org/32563
Submitter: Vinay Vithal Mahuli (<email address hidden>)

[OpenContrail Admin (ci-admin-f)]

Reviewed: https://review.opencontrail.org/32563
Committed: http://github.com/Juniper/contrail-controller/commit/059b059c6bf0db87cea703b368c97565652bdac8
Submitter: Zuul (<email address hidden>)
Branch: R3.2.3.x

commit 059b059c6bf0db87cea703b368c97565652bdac8
Author: Ananth Suryanarayana <email address hidden>
Date: Thu Apr 27 15:34:46 2017 -0700

Add BGP Notification Flag support in GR

https://tools.ietf.org/html/draft-ietf-idr-bgp-gr-notification-10

Attempt GR Helper mode for all received notifications (and hold-timer expiry)
except HardReset and PeerDeconfigured.

Always send Notifications. NotificationFlag support has been in JUNOS already
for a while. Older versions of control-node already skips most of the
notifications received (and triggers GR helper mode)

Also fix a couple of nits found by cpplint

Closes-Bug: 1680047
Change-Id: Ic0462e9483dda8ee2f6c1be503bf1c120c3d6786
(cherry picked from commit c45ed8bbbdb2bf008f22b45e04a49d377e26c43e)