Hi all,


this is an update on the earlier "[RFC net-next] VPLS support".  Note
I've changed the subject lines on some of the patches to better reflect
what they really do (tbh the earlier subject lines were crap.)

As previously, iproute2 / FRR patches are at:
- https://github.com/eqvinox/vpls-iproute2
- https://github.com/opensourcerouting/frr/commits/vpls
while this patchset is also available at:
- https://github.com/eqvinox/vpls-linux-kernel
(but please be aware that I'm amending and rebasing commits)

The NVGRE implementation in the 3rd patch in this series is actually an
accident - I was just wiring up gretap as a reference;  only after I was
done I noticed that that sums up to NVGRE, more or less.  IMHO, it does
serve well to demonstrate the bridge changes are not VPLS-specific.

To refer some notes from the first announce mail:

I've tested some basic setups, the chain from LDP down into the kernel
works at least in these.  FRR has some testcases around from OpenBSD
VPLS support, I haven't wired that up to run against Linux / this
patchset yet.

Same as before (API didn't change).

The patchset needs a lot of polishing (yes I left my TODO notes in the
commit messages), for now my primary concern is overall design
feedback.  Roopa has already provided a lot of input (Thanks!);  the
major topic I'm expecting to get discussion on is the bridge FDB
changes.

Got some useful input;  but still need feedback on the bridge FDB
changes (first 2 patches).  I don't believe it to have a significant
impact on existing bridge operation, and I believe a multipoint tunnel
driver without its own FDB (e.g. NVGRE in this set) should perform
better than one with its own FDB (e.g. existing VXLAN).

P.S.: For a little context on the bridge FDB changes - I'm hoping to
find some time to extend this to the MDB to allow aggregating dst
metadata and handing down a list of dst metas on TX.  This isn't
specifically for VPLS but rather to give sufficient information to the
802.11 stack to allow it to optimize selecting rates (or unicasting)
for multicast traffic by having the multicast subscriber list known.
This is done by major commercial wifi solutions (e.g. google "dynamic
multicast optimization".)

You can find hacks at this on:
https://github.com/eqvinox/vpls-linux-kernel/tree/mdb-hack
Please note that the patches in that branch are not at an acceptable
quality level, but you can see the semantic relation to 802.11.

I would, however, like to point out that this branch has pseudo-working
IGMP/MLD snooping for VPLS, and it'd be 20-ish lines to add it to NVGRE
(I'll do that as soon as I get to it, it'll pop up on that branch too.)

This is relevant to the discussion because it's a feature which is
non-obvious (to me) on how to do with the VXLAN model of having an
entirely separate FDB.  Meanwhile, with this architecture, the proof of
concept / hack is coming in at a measly cost of:
8 files changed, 176 insertions(+), 15 deletions(-)


Cheers,

-David

--- diffstat:

include/linux/netdevice.h      |  18 ++++++
include/net/dst_metadata.h     |  51 ++++++++++++++---
include/net/ip_tunnels.h       |   5 ++
include/uapi/linux/lwtunnel.h  |   8 +++
include/uapi/linux/neighbour.h |   2 +
include/uapi/linux/rtnetlink.h |   5 ++
net/bridge/br.c                |   2 +-
net/bridge/br_device.c         |   4 ++
net/bridge/br_fdb.c            | 119 ++++++++++++++++++++++++++++++++--------
net/bridge/br_input.c          |   6 +-
net/bridge/br_private.h        |   6 +-
net/core/lwtunnel.c            |   1 +
net/ipv4/ip_gre.c              |  40 ++++++++++++--
net/ipv4/ip_tunnel.c           |   1 +
net/ipv4/ip_tunnel_core.c      |  87 +++++++++++++++++++++++------
net/mpls/Kconfig               |  11 ++++
net/mpls/Makefile              |   1 +
net/mpls/af_mpls.c             | 113 ++++++++++++++++++++++++++++++++------
net/mpls/internal.h            |  44 +++++++++++++--
net/mpls/vpls.c                | 550 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
20 files changed, 990 insertions(+), 84 deletions(-)