On 2022-10-21 18:30, Vladimir Oltean wrote:
On Fri, Oct 21, 2022 at 03:16:21PM +0200, netdev@kapio-technology.com wrote:
As it is now in the bridge, the locked port part is handled before learning in the ingress data path, so with BR_LEARNING and BR_PORT_LOCKED, I think it will work as it does now except link local packages.
If link-local learning is enabled on a locked port, I think those addresses should also be learned with the BR_FDB_LOCKED flag. The creation of those locked FDB entries can be further suppressed by the BROPT_NO_LL_LEARN flag.
If your suggestion of BR_LEARNING causing BR_FDB_LOCKED on a locked port, I guess it would be implemented under br_fdb_update() and BR_LEARNING + BR_PORT_LOCKED would go together, forcing BR_LEARNING in this case, thus also for all drivers?
Yes, basically where this is placed right now (in br_handle_frame_finish):
if (p->flags & BR_PORT_LOCKED) { struct net_bridge_fdb_entry *fdb_src = br_fdb_find_rcu(br, eth_hdr(skb)->h_source, vid);
if (!fdb_src) { unsigned long flags = 0; if (p->flags & BR_PORT_MAB) { ~~~~~~~~~~~~~~~~~~~~~~~~ except check for BR_LEARNING __set_bit(BR_FDB_LOCKED, &flags); br_fdb_update(br, p, eth_hdr(skb)->h_source, vid, flags); } goto drop; } else if (READ_ONCE(fdb_src->dst) != p || test_bit(BR_FDB_LOCAL, &fdb_src->flags) || test_bit(BR_FDB_LOCKED, &fdb_src->flags)) { goto drop; }}
As I don't know what implications it would have for other drivers to have learning forced enabled on locked ports, I cannot say if it is a good idea or not. Right now learning is not forced either way as is, but the consensus is that learning should be off with locked ports, which it would be either way in the common case I think.