On 10.11.2017 00:10, Andrew Lunn wrote: > The linux bridge supports IGMP snooping. It will listen to IGMP > reports on bridge ports and keep track of which groups have been > joined on an interface. It will then forward multicast based on this > group membership. > > When the bridge adds or removed groups from an interface, it uses > switchdev to request the hardware add an mdb to a port, so the > hardware can perform the selective forwarding between ports. > > What is not covered by the current bridge code, is IGMP joins/leaves > from the host on the brX interface. These are not reported via > switchdev so that hardware knows the local host is interested in the > multicast frames. > > Luckily, the bridge does track joins/leaves on the brX interface. The > code is obfusticated, which is why i missed it with my first attempt. > So the first patch tries to remove this obfustication. Currently, > there is no notifications sent when the bridge interface joins a > group. The second patch adds them. bridge monitor then shows > joins/leaves in the same way as for other ports of the bridge. > > Then starts the work passing down to the hardware that the host has > joined/left a group. The existing switchdev mdb object cannot be used, > since the semantics are different. The existing > SWITCHDEV_OBJ_ID_PORT_MDB is used to indicate a specific multicast > group should be forwarded out that port of the switch. However here we > require the exact opposite. We want multicast frames for the group > received on the port to the forwarded to the host. Hence add a new > object SWITCHDEV_OBJ_ID_HOST_MDB, a multicast database entry to > forward to the host. This new object is then propagated through the > DSA layers. No DSA driver changes should be needed, this should just > work... > > This version fixes up the nitpick from Nikolay, removes an unrelated > white space change, and adds in a patch adding a few const attributes > to a couple of functions taking a port parameter, in order to stop the > following patch produces warnings. > > Acked-by: Stephen Hemminger <step...@networkplumber.org> > > Andrew Lunn (6): > net: bridge: Rename mglist to host_joined > net: bridge: Send notification when host join/leaves a group > net: bridge: Add/del switchdev object on host join/leave > net: dsa: slave: Handle switchdev host mdb add/del > net: dsa: add more const attributes > net: dsa: switch: Don't add CPU port to an mdb by default > > include/net/switchdev.h | 1 + > net/bridge/br_input.c | 2 +- > net/bridge/br_mdb.c | 54 > +++++++++++++++++++++++++++++++++++++++++++---- > net/bridge/br_multicast.c | 18 ++++++++++------ > net/bridge/br_private.h | 2 +- > net/dsa/dsa_priv.h | 4 ++-- > net/dsa/port.c | 6 +++--- > net/dsa/slave.c | 13 ++++++++++++ > net/dsa/switch.c | 2 +- > net/switchdev/switchdev.c | 2 ++ > 10 files changed, 85 insertions(+), 19 deletions(-) >
Andrew, overall looks good to me, thanks for keeping the acks and incorporating the changes. Just one note - in the future please add the reviewers to the CC list. I've been reviewing and suggesting changes to this set since its RFC/WIP version but it's making it harder to track when I'm not receiving the new versions and have to search for them on netdev. Thanks, Nik
