net/multicast: should not send source list records when have filter mode change
Based on RFC3376 5.1 and RFC3810 6.1
If the per-interface listening change that triggers the new report is
a filter mode change, then the next [Robustness Variable] State
Change Reports will include a Filter Mode Change Record. This
applies even if any number of source list changes occur in that
period.
Old State New State State Change Record Sent
--------- --------- ------------------------
INCLUDE (A) EXCLUDE (B) TO_EX (B)
EXCLUDE (A) INCLUDE (B) TO_IN (B)
So we should not send source-list change if there is a filter-mode change.
Here are two scenarios:
1. Group deleted and filter mode is EXCLUDE, which means we need send a
TO_IN { }.
2. Not group deleted, but has pcm->crcount, which means we need send a
normal filter-mode-change.
At the same time, if the type is ALLOW or BLOCK, and have psf->sf_crcount,
we stop add records and decrease sf_crcount directly
Reference: https://www.ietf.org/mail-archive/web/magma/current/msg01274.html
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2 files changed
