Subject: Re: [PATCH V3 net-next 1/4] net: bridge: add fdb flag to extent locked port feature

From: Hans Schultz <[email-masked]>
Date: Thu, 02 Jun 2022 14:08:41 +0200

>
> I think Hans is testing with mv88e6xxx which dumps entries directly from
> HW via ndo_fdb_dump(). See dsa_slave_port_fdb_do_dump() which sets
> NTF_SELF.
>
> Hans, are you seeing the entry twice? Once with 'master' and once with
> 'self'?
>

When replacing a locked entry it looks like this:

# bridge fdb show dev eth6 | grep 4c
00:4c:4c:4c:4c:4c vlan 1 master br0 extern_learn offload locked

# bridge fdb replace 00:4c:4c:4c:4c:4c dev eth6 vlan 1 master static ; bridge fdb show dev eth6 | grep 4c
00:4c:4c:4c:4c:4c vlan 1 self static

The problem is then that the function
br_fdb_find_rcu(br,eth_hdr(skb)->h_source, vid);
, where the h_source and vid is the entry above, does not find the entry.
My hypothesis was then that this is because of the 'self' flag that I
see.

I am thinking that the function dsa_slave_port_fdb_do_dump() is only for
debug, and thus does not really set any flags in the bridge modules FDB,
but then I don't understand why the above find function does not find
the entry?