• Felix Fietkau's avatar
    bridge: multicast to unicast · 6db6f0ea
    Felix Fietkau authored
    
    
    Implements an optional, per bridge port flag and feature to deliver
    multicast packets to any host on the according port via unicast
    individually. This is done by copying the packet per host and
    changing the multicast destination MAC to a unicast one accordingly.
    
    multicast-to-unicast works on top of the multicast snooping feature of
    the bridge. Which means unicast copies are only delivered to hosts which
    are interested in it and signalized this via IGMP/MLD reports
    previously.
    
    This feature is intended for interface types which have a more reliable
    and/or efficient way to deliver unicast packets than broadcast ones
    (e.g. wifi).
    
    However, it should only be enabled on interfaces where no IGMPv2/MLDv1
    report suppression takes place. This feature is disabled by default.
    
    The initial patch and idea is from Felix Fietkau.
    Signed-off-by: default avatarFelix Fietkau <nbd@nbd.name>
    [linus.luessing@c0d3.blue: various bug + style fixes, commit message]
    Signed-off-by: default avatarLinus Lüssing <linus.luessing@c0d3.blue>
    Reviewed-by: default avatarNikolay Aleksandrov <nikolay@cumulusnetworks.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    6db6f0ea