On 13/04/2022 12:51, Joachim Wiberg wrote:
> On Tue, Apr 12, 2022 at 21:27, Nikolay Aleksandrov <razor@xxxxxxxxxxxxx> wrote:
>> On 11/04/2022 16:38, Joachim Wiberg wrote:
>>> @@ -526,6 +526,10 @@ void br_dev_setup(struct net_device *dev)
>>> br->bridge_ageing_time = br->ageing_time = BR_DEFAULT_AGEING_TIME;
>>> dev->max_mtu = ETH_MAX_MTU;
>>> + br_opt_toggle(br, BROPT_UNICAST_FLOOD, 1);
>> This one must be false by default. It changes current default behaviour.
>> Unknown unicast is not currently passed up to the bridge if the port is
>> not in promisc mode, this will change it. You'll have to make it consistent
>> with promisc (e.g. one way would be for promisc always to enable unicast flood
>> and it won't be possible to be disabled while promisc).
>
> Ouch, my bad! Will look into how to let this have as little impact as
> possible. I like your semantics there, promisc should always win.
>
>>> + br_opt_toggle(br, BROPT_MCAST_FLOOD, 1);
>>> + br_opt_toggle(br, BROPT_BCAST_FLOOD, 1);
>>
>> s/1/true/ for consistency
>
> Of course, thanks!
>
>>> @@ -118,7 +118,8 @@ int br_handle_frame_finish(struct net *net, struct sock *sk, struct sk_buff *skb
>>> /* by definition the broadcast is also a multicast address */
>>> if (is_broadcast_ether_addr(eth_hdr(skb)->h_dest)) {
>>> pkt_type = BR_PKT_BROADCAST;
>>> - local_rcv = true;
>>> + if (br_opt_get(br, BROPT_BCAST_FLOOD))
>>> + local_rcv = true;
>>> } else {
>>> pkt_type = BR_PKT_MULTICAST;
>>> if (br_multicast_rcv(&brmctx, &pmctx, vlan, skb, vid))
>>> @@ -161,12 +162,16 @@ int br_handle_frame_finish(struct net *net, struct sock *sk, struct sk_buff *skb
>>> }
>>> mcast_hit = true;
>>> } else {
>>> - local_rcv = true;
>>> - br->dev->stats.multicast++;
>>> + if (br_opt_get(br, BROPT_MCAST_FLOOD)) {
>>> + local_rcv = true;
>>> + br->dev->stats.multicast++;
>>> + }
>>> }
>>> break;
>>> case BR_PKT_UNICAST:
>>> dst = br_fdb_find_rcu(br, eth_hdr(skb)->h_dest, vid);
>>> + if (!dst && br_opt_get(br, BROPT_UNICAST_FLOOD))
>>> + local_rcv = true;
>>> break;
>>
>> This adds new tests for all fast paths for host traffic, especially
>> the port - port communication which is the most critical one. Please
>> at least move the unicast test to the "else" block of "if (dst)"
>> later.
>
> OK, will fix!
>
>> The other tests can be moved to host only code too, but would require
>> bigger changes. Please try to keep the impact on the fast-path at
>> minimum.
>
> Interesting, you mean by speculatively setting local_rcv = true and
> postpone the decsion to br_pass_frame_up(), right? Yeah that would
> indeed be a bit more work.
Yes, I was thinking maybe local_rcv can become an enum with an exact reason for the
local_rcv, so if it's > 0 do the local_rcv and br_pass_frame_up() then
can make a proper decision without passing all of the vars. I haven't tried it,
so not sure if it's feasible. :)
