[B.A.T.M.A.N.] [PATCH 0/6] batman-adv: Add routeable multicast optimizations

Linus L├╝ssing linus.luessing at c0d3.blue
Wed Apr 24 03:19:13 CEST 2019

The following patchset fills the next gaps in the multicast address
rules page by adding support for group-aware optimizations for
multicast addresses of scope greater than link-local. So far, only
link-local addresses were optimized as packets with routeable
addresses not only need to be forwarded to local multicast listeners
but also multicast routers.

"Handling rules depending on multicast address:" [0]


* Ipv4, link-local: supported without bridges
* IPv6, link-local: supported
* IPv4, routeable: support planned.
* IPv6, routeable: support planned.


* Ipv4, link-local: supported without bridges
* IPv6, link-local: supported
* IPv4, routeable: supported without bridges.
* IPv6, routeable: supported.

The first patch is a fix for the maint branch addressing tickets #369
and #370.

Then patches 2 to 4 are basically some cleanups and restructuring of the
current code.

Patch 5 adds the detection of multicast routers and announces
that via two new flags in its multicast TVLV. TVLV receivers will
memorize this and fill lists similar to how we already do for the
WANT_ALL_IPV4/IPV6 flags. Currently the detection for bridged-in
IPv6 multicast routers is not quite what the RFC for multicast router
discovery suggests. But once the MRD implementation in the Linux bridge
has matured a bit, I'm going to swap this simplified approach with
tapping into the bridge once more, asking the bridge for the presence of
multicast routers on the link. (This will then also add support for
"IPv4, routeable, with bridges")

Finally, patch 6 implements the changes to the forwarding plane,
utilizing the new information we have gathered with patch 5.

Regards, Linus

[0]: https://www.open-mesh.org/projects/batman-adv/wiki/Multicast-optimizations-tech#Handling-rules-depending-on-multicast-address

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