On Tue, 2018-06-12 at 15:42 +0000, Fu, Qiaobin wrote:
> The new action inheritdsfield copies the field DS of
> IPv4 and IPv6 packets into skb->priority. This enables
> later classification of packets based on the DS field.
>
> v4:
> *Not allow setting flags other than the expected ones.
>
> *Allow dumping the pure flags.
>
> Original idea by Jamal Hadi Salim <j...@mojatatu.com>
>
> Signed-off-by: Qiaobin Fu <qiaob...@bu.edu>
> Reviewed-by: Michel Machado <mic...@digirati.com.br>
> ---
>
[...]
> @@ -41,6 +44,25 @@ static int tcf_skbedit(struct sk_buff *skb, const struct
> tc_action *a,
>
> if (d->flags & SKBEDIT_F_PRIORITY)
> skb->priority = d->priority;
> + if (d->flags & SKBEDIT_F_INHERITDSFIELD) {
> + int wlen = skb_network_offset(skb);
> +
> + switch (tc_skb_protocol(skb)) {
> + case htons(ETH_P_IP):
> + wlen += sizeof(struct iphdr);
> + if (!pskb_may_pull(skb, wlen))
> + goto err;
> + skb->priority = ipv4_get_dsfield(ip_hdr(skb)) >> 2;
> + break;
> +
> + case htons(ETH_P_IPV6):
> + wlen += sizeof(struct ipv6hdr);
> + if (!pskb_may_pull(skb, wlen))
> + goto err;
> + skb->priority = ipv6_get_dsfield(ipv6_hdr(skb)) >> 2;
> + break;
> + }
> + }
> if (d->flags & SKBEDIT_F_QUEUE_MAPPING &&
> skb->dev->real_num_tx_queues > d->queue_mapping)
> skb_set_queue_mapping(skb, d->queue_mapping);
> @@ -53,6 +75,10 @@ static int tcf_skbedit(struct sk_buff *skb, const struct
> tc_action *a,
>
> spin_unlock(&d->tcf_lock);
> return d->tcf_action;
> +
> +err:
> + spin_unlock(&d->tcf_lock);
> + return TC_ACT_SHOT;
> }
>
sorry for asking this when the patch is a v4...
I spotted this, as I'm rebasing a small series that removes the tcf_lock
from the data plane of skbedit to gain some speed, and it converts the
stats to be per-cpu counters.
in the code above, you are catching failures of pskb_may_pull(skb) and
then you return TC_ACT_SHOT. That's OK, but I think you should update the
drop counter, like other TC actions do.
If you (author / reviewers) think this is a minor issue, like I do think,
then I can add the missing update in my series and post it when net-next
reopens.
WDYT?
thank you in advance!
regards,
--
davide
