Re: [RFC PATCH net-next 3/6 v2] net/sched: cls_flower: Add ematch support

[Marcelo Leitner <mleitner@redhat.com>]

On Tue, Jan 29, 2019 at 10:02:03AM +0200, Paul Blakey wrote:
> TODO: handle EEXist.
> 
> Signed-off-by: Paul Blakey <paulb@mellanox.com>
> ---
>  include/uapi/linux/pkt_cls.h |  2 ++
>  net/sched/cls_flower.c       | 22 ++++++++++++++++++----
>  2 files changed, 20 insertions(+), 4 deletions(-)
> 
> diff --git a/include/uapi/linux/pkt_cls.h b/include/uapi/linux/pkt_cls.h
> index 121f1ef..d848d6d 100644
> --- a/include/uapi/linux/pkt_cls.h
> +++ b/include/uapi/linux/pkt_cls.h
> @@ -506,6 +506,8 @@ enum {
>  	TCA_FLOWER_KEY_CT_LABELS,
>  	TCA_FLOWER_KEY_CT_LABELS_MASK,
>  
> +	TCA_FLOWER_EMATCHES,
> +
>  	__TCA_FLOWER_MAX,
>  };
>  
> diff --git a/net/sched/cls_flower.c b/net/sched/cls_flower.c
> index bf74a31..f11fda0 100644
> --- a/net/sched/cls_flower.c
> +++ b/net/sched/cls_flower.c
> @@ -104,6 +104,7 @@ struct cls_fl_filter {
>  	struct rhash_head ht_node;
>  	struct fl_flow_key mkey;
>  	struct tcf_exts exts;
> +	struct tcf_ematch_tree ematches;
>  	struct tcf_result res;
>  	struct fl_flow_key key;
>  	struct list_head list;
> @@ -332,10 +333,14 @@ static int fl_classify(struct sk_buff *skb, const struct tcf_proto *tp,
>  		fl_set_masked_key(&skb_mkey, &skb_key, mask);
>  
>  		f = fl_lookup(mask, &skb_mkey, &skb_key);
> -		if (f && !tc_skip_sw(f->flags)) {
> -			*res = f->res;
> -			return tcf_exts_exec(skb, &f->exts, res);
> -		}
> +		if (!f || tc_skip_sw(f->flags))
> +			continue;
> +
> +		if (!tcf_em_tree_match(skb, &f->ematches, NULL))
> +			continue;

Considering just the recirc_id (and not the other fields supported by
ematch), have you considered integrating recirc_id match on flow
dissector instead?  It would avoid the matching in 2 steps here and
benefit from the hashing.

> +
> +		*res = f->res;
> +		return tcf_exts_exec(skb, &f->exts, res);
>  	}
>  	return -1;
>  }
> @@ -388,6 +393,7 @@ static bool fl_mask_put(struct cls_fl_head *head, struct fl_flow_mask *mask,
>  static void __fl_destroy_filter(struct cls_fl_filter *f)
>  {
>  	tcf_exts_destroy(&f->exts);
> +	tcf_em_tree_destroy(&f->ematches);
>  	tcf_exts_put_net(&f->exts);
>  	kfree(f);
>  }
> @@ -523,6 +529,7 @@ static void *fl_get(struct tcf_proto *tp, u32 handle)
>  static const struct nla_policy fl_policy[TCA_FLOWER_MAX + 1] = {
>  	[TCA_FLOWER_UNSPEC]		= { .type = NLA_UNSPEC },
>  	[TCA_FLOWER_CLASSID]		= { .type = NLA_U32 },
> +	[TCA_FLOWER_EMATCHES]		= { .type = NLA_NESTED },
>  	[TCA_FLOWER_INDEV]		= { .type = NLA_STRING,
>  					    .len = IFNAMSIZ },
>  	[TCA_FLOWER_KEY_ETH_DST]	= { .len = ETH_ALEN },
> @@ -1348,6 +1355,10 @@ static int fl_set_parms(struct net *net, struct tcf_proto *tp,
>  	if (err < 0)
>  		return err;
>  
> +	err = tcf_em_tree_validate(tp, tb[TCA_FLOWER_EMATCHES], &f->ematches);
> +	if (err < 0)
> +		return err;
> +
>  	if (tb[TCA_FLOWER_CLASSID]) {
>  		f->res.classid = nla_get_u32(tb[TCA_FLOWER_CLASSID]);
>  		tcf_bind_filter(tp, &f->res, base);
> @@ -2143,6 +2154,9 @@ static int fl_dump(struct net *net, struct tcf_proto *tp, void *fh,
>  	    nla_put_u32(skb, TCA_FLOWER_CLASSID, f->res.classid))
>  		goto nla_put_failure;
>  
> +	if (tcf_em_tree_dump(skb, &f->ematches, TCA_FLOWER_EMATCHES) < 0)
> +		goto nla_put_failure;
> +
>  	key = &f->key;
>  	mask = &f->mask->key;
>  
> -- 
> 1.8.3.1
>