bridge: join all-snoopers multicast address
authorLinus Lüssing <linus.luessing@c0d3.blue>
Mon, 21 Jan 2019 06:26:27 +0000 (07:26 +0100)
committerDavid S. Miller <davem@davemloft.net>
Wed, 23 Jan 2019 01:18:08 +0000 (17:18 -0800)
commit4effd28c1245303dce7fd290c501ac2c11052114
tree93942c9d3f41fc3e58de6ce99fbc03319ddaa17e
parenta2e2ca3bebe273055a212d754ffe4e0264192d74
bridge: join all-snoopers multicast address

Next to snooping IGMP/MLD queries RFC4541, section 2.1.1.a) recommends
to snoop multicast router advertisements to detect multicast routers.

Multicast router advertisements are sent to an "all-snoopers"
multicast address. To be able to receive them reliably, we need to
join this group.

Otherwise other snooping switches might refrain from forwarding these
advertisements to us.

Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: David S. Miller <davem@davemloft.net>
include/uapi/linux/in.h
net/bridge/br_multicast.c
net/ipv6/mcast.c