tree 1352a7121dfe4dfafdb0379547c4ca01770beb15
parent 91573e1d7d027ccf7a086c20366fe1216854b8e6
author Pier Luigi <pierventre@hotmail.com> 1516353893 +0100
committer Charles Chan <rascov@gmail.com> 1518215826 -0800

[CORD-2483] Mcast does not forward traffic to all the sinks

Rationale: if we add more than one sink a number
of sink add events are generated. For each event
we create a mcast path, right now we do not support
Mcast group editing. This means that a new nextobjective
will be created for each sink.

In particular, this patch enables the mcast group editing
to solve the following issue:

Sink1 arrives -> fwdObj A -> Next B (this has one output)
Sink2 arrives -> fwdObj A -> Next C (this has two outputs)

Next B and Next C shares a part of the chain. Reordering happens
during the creation of the Nexts:

Next C created -> flow A -> Group C
Next B created -> flow A -> Group B

Failure, traffic does not reach all the sinks. Other side effect is the
disalignment between SR app and flow/group because McastHandler believes
mcast group is associated to the Next C

It includes minor refactoring of the group handler

Change-Id: Ib59ba6b63ff411ed46ca8216677046a78cc92ac6