Re: [PATCH net-next V5 4/4] net/sched: Introduce act_tunnel_key

From: Jamal Hadi Salim <jhs@mojatatu.com>
To: Hadar Hen Zion <hadarh@mellanox.com>,
	"David S. Miller" <davem@davemloft.net>
Cc: netdev@vger.kernel.org, Jiri Pirko <jiri@mellanox.com>,
	Jiri Benc <jbenc@redhat.com>,
	Shmulik Ladkani <shmulik.ladkani@gmail.com>,
	Tom Herbert <tom@herbertland.com>,
	Eric Dumazet <edumazet@google.com>,
	Cong Wang <xiyou.wangcong@gmail.com>,
	Amir Vadai <amirva@mellanox.com>,
	Or Gerlitz <ogerlitz@mellanox.com>, Amir Vadai <amir@vadai.me>
Subject: Re: [PATCH net-next V5 4/4] net/sched: Introduce act_tunnel_key
Date: Tue, 6 Sep 2016 06:49:46 -0400	[thread overview]
Message-ID: <b6d6b736-bc45-3216-6109-0b67a54fb704@mojatatu.com> (raw)
In-Reply-To: <1472986555-14949-5-git-send-email-hadarh@mellanox.com>

On 16-09-04 06:55 AM, Hadar Hen Zion wrote:
> From: Amir Vadai <amir@vadai.me>
>
> This action could be used before redirecting packets to a shared tunnel
> device, or when redirecting packets arriving from a such a device.
>
> The action will release the metadata created by the tunnel device
> (decap), or set the metadata with the specified values for encap
> operation.
>
> For example, the following flower filter will forward all ICMP packets
> destined to 11.11.11.2 through the shared vxlan device 'vxlan0'. Before
> redirecting, a metadata for the vxlan tunnel is created using the
> tunnel_key action and it's arguments:
>
> $ filter add dev net0 protocol ip parent ffff: \
>     flower \
>       ip_proto 1 \
>       dst_ip 11.11.11.2 \
>     action tunnel_key set \
>       src_ip 11.11.0.1 \
>       dst_ip 11.11.0.2 \
>       id 11 \
>     action mirred egress redirect dev vxlan0
>

Syntax error above. Regardless:
Please verify by running a test and send a packet or two
and verify that stats are incremented (I know it may sound silly to
ask but it is important).

> +static int tunnel_key_act(struct sk_buff *skb, const struct tc_action *a,
> +			  struct tcf_result *res)
> +{
> +	struct tcf_tunnel_key *t = to_tunnel_key(a);
> +	struct tcf_tunnel_key_params *params;
> +	int action;
> +
> +	rcu_read_lock();
> +
> +	params = rcu_dereference(t->params);
> +
> +	tcf_lastuse_update(&t->tcf_tm);
> +	bstats_cpu_update(this_cpu_ptr(t->common.cpu_bstats), skb);
> +	action = params->action;
> +
> +	switch (params->tcft_action) {
> +	case TCA_TUNNEL_KEY_ACT_RELEASE:
> +		skb_dst_drop(skb);
> +		break;
> +	case TCA_TUNNEL_KEY_ACT_SET:
> +		skb_dst_drop(skb);
> +		skb_dst_set(skb, dst_clone(&params->tcft_enc_metadata->dst));
> +		break;
> +	default:
> +		WARN_ONCE(1, "Bad tunnel_key action.\n");
> +		break;

slow path (_init()) is already checking for a bad tcft_act so it seems
unnecessary to have the default.
If you have to keep default would be useful to print the value as well.

Other than that looks good.
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>

cheers,
jamal