Re: [PATCH v2 net-next 0/4] bridge: 802.1ad vlan protocol support

From: Toshiaki Makita <redacted>
Date: Tue, 10 Jun 2014 20:59:21 +0900

Currently bridge vlan filtering doesn't work fine with 802.1ad protocol.
Only if a bridge is configured without pvid, the bridge receives only
802.1ad tagged frames and no STP is used, it will work.
Otherwise:
- If pvid is configured, it can put only 802.1Q tags but cannot put 802.1ad
  tags.
- If 802.1Q and 802.1ad tagged frames arrive in mixture, it applies filtering
  regardless of their protocols.
- While an 802.1ad bridge should use another mac address for STP BPDU and
  should forward customer's BPDU frames, it can't.
Thus, we can't properly handle frames once 802.1ad is used.

Handling 802.1ad is useful if we want to allow stacked vlans to be used,
e.g., guest VMs wants to use vlan tags and the host also wants to segregate
guest's traffic from other guests' by vlan tags.

Here is the image describing how to configure a bridge to filter VMs traffic.

         +-------+p/u   +-----+  +---------+
 +----+  |       |------|vnet0|--|User A VM|
 |eth0|--|802.1ad|      +-----+  +---------+
 +----+  |bridge |p/u   +-----+  +---------+
         |       |------|vnet1|--|User B VM|
         +-------+      +-----+  +---------+
p/u: pvid/untagged

This patch set enables us to set vlan protocols per bridge.
This tries to implement a bridge like S-VLAN component in IEEE 802.1Q-2011
spec.

Series applied, thanks.