>On Thu, 6 Apr 2023 19:30:34 +0800 (CST) yang.yang29@xxxxxxxxxx wrote:
>> From: xu xin <xu.xin16@xxxxxxxxxx>
>>
>> This creates six drop reasons as follows, which will help users know the
>> specific reason why bridge drops the packets when forwarding.
>>
>> 1) SKB_DROP_REASON_BRIDGE_FWD_NO_BACKUP_PORT: failed to get a backup
>> port link when the destination port is down.
>>
>> 2) SKB_DROP_REASON_BRIDGE_FWD_SAME_PORT: destination port is the same
>> with originating port when forwarding by a bridge.
>>
>> 3) SKB_DROP_REASON_BRIDGE_NON_FORWARDING_STATE: the bridge's state is
>> not forwarding.
>>
>> 4) SKB_DROP_REASON_BRIDGE_NOT_ALLOWED_EGRESS: the packet is not allowed
>> to go out through the port due to vlan filtering.
>>
>> 5) SKB_DROP_REASON_BRIDGE_SWDEV_NOT_ALLOWED_EGRESS: the packet is not
>> allowed to go out through the port which is offloaded by a hardware
>> switchdev, checked by nbp_switchdev_allowed_egress().
>>
>> 6) SKB_DROP_REASON_BRIDGE_BOTH_PORT_ISOLATED: both source port and dest
>> port are in BR_ISOLATED state when bridge forwarding.
>
>> @@ -338,6 +344,33 @@ enum skb_drop_reason {
>> * for another host.
>> */
>> SKB_DROP_REASON_IPV6_NDISC_NS_OTHERHOST,
>> + /** @SKB_DROP_REASON_BRIDGE_FWD_NO_BACKUP_PORT: failed to get a backup
>> + * port link when the destination port is down.
>> + */
>
>That's not valid kdoc. Text can be on the same line as the value only
>in one-line comments. Otherwise:
> /**
> * @VALUE: bla bla bla
> * more blas.
> */
>
Ok, I didn't notice that.
>> +static inline bool should_deliver(const struct net_bridge_port *p, const struct sk_buff *skb,
>> + enum skb_drop_reason *need_reason)
>> {
>> struct net_bridge_vlan_group *vg;
>> + enum skb_drop_reason reason;
>>
>> vg = nbp_vlan_group_rcu(p);
>> - return ((p->flags & BR_HAIRPIN_MODE) || skb->dev != p->dev) &&
>> - p->state == BR_STATE_FORWARDING && br_allowed_egress(vg, skb) &&
>> - nbp_switchdev_allowed_egress(p, skb) &&
>> - !br_skb_isolated(p, skb);
>> + if (!(p->flags & BR_HAIRPIN_MODE) && skb->dev == p->dev) {
>> + reason = SKB_DROP_REASON_BRIDGE_FWD_SAME_PORT;
>> + goto undeliverable;
>> + }
>> + if (p->state != BR_STATE_FORWARDING) {
>> + reason = SKB_DROP_REASON_BRIDGE_NON_FORWARDING_STATE;
>> + goto undeliverable;
>> + }
>> + if (!br_allowed_egress(vg, skb)) {
>> + reason = SKB_DROP_REASON_BRIDGE_NOT_ALLOWED_EGRESS;
>> + goto undeliverable;
>> + }
>> + if (!nbp_switchdev_allowed_egress(p, skb)) {
>> + reason = SKB_DROP_REASON_BRIDGE_SWDEV_NOT_ALLOWED_EGRESS;
>> + goto undeliverable;
>> + }
>> + if (br_skb_isolated(p, skb)) {
>> + reason = SKB_DROP_REASON_BRIDGE_BOTH_PORT_ISOLATED;
>> + goto undeliverable;
>> + }
>> + return true;
>> +
>> +undeliverable:
>> + if (need_reason)
>> + *need_reason = reason;
>> + return false;
>
>You can return the reason from this function. That's the whole point of
>SKB_NOT_DROPPED_YET existing and being equal to 0.
>
If returning the reasons, then the funtion will have to be renamed because
'should_deliever()' is expected to return a non-zero value when it's ok to
deliever. I don't want to change the name here, and it's better to keep its
name and use the pointer to store the reasons.
>Which is not to say that I know whether the reasons are worth adding
>here. We'll need to hear from bridge experts on that.
