The below "jumbo" patch fixes the following problems in MLDv2.
1) Add necessary "ntohs" to recent "pskb_may_pull" check [breaks
all nonzero source queries on little-endian (!)]
2) Add locking to source filter list [resend of prior patch]
3) fix "mld_marksources()" to
a) send nothing when all queried sources are excluded
b) send full exclude report when source queried sources are
not excluded
c) don't schedule a timer when there's nothing to report
NOTE: RFC 3810 specifies the source list should be saved and each
source reported individually as an IS_IN. This is an obvious DOS
path, requiring the host to store and then multicast as many sources
as are queried (e.g., millions...). This alternative sends a full,
relevant report that's limited to number of sources present on the
machine.
4) fix "add_grec()" to send empty-source records when it should
The original check doesn't account for a non-empty source
list with all sources inactive; the new code keeps that
short-circuit case, and also generates the group header
with an empty list if needed.
5) fix mca_crcount decrement to be after add_grec(), which needs
its original value
These issues (other than item #1 ;-) ) were all found by Yan Zheng,
much thanks!
Signed-off-by: David L Stevens <dlstevens@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>