Re: [PATCH v2 net-next 2/2] net/sched: allow flower to match tunnel options

Wed, Sep 27, 2017 at 02:52:06PM CEST, simon.horman@netronome.com wrote:

On Wed, Sep 27, 2017 at 01:08:22PM +0200, Jiri Pirko wrote:

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Wed, Sep 27, 2017 at 11:27:33AM CEST, simon.horman@netronome.com wrote:

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On Wed, Sep 27, 2017 at 11:10:05AM +0200, Jiri Pirko wrote:

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Wed, Sep 27, 2017 at 10:16:34AM CEST, simon.horman@netronome.com wrote:

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enum flow_dissector_key_id {
	FLOW_DISSECTOR_KEY_CONTROL, /* struct flow_dissector_key_control */
	FLOW_DISSECTOR_KEY_BASIC, /* struct flow_dissector_key_basic */

@@ -205,6 +217,7 @@ enum flow_dissector_key_id {

	FLOW_DISSECTOR_KEY_MPLS, /* struct flow_dissector_key_mpls */
	FLOW_DISSECTOR_KEY_TCP, /* struct flow_dissector_key_tcp */
	FLOW_DISSECTOR_KEY_IP, /* struct flow_dissector_key_ip */
+	FLOW_DISSECTOR_KEY_ENC_OPTS, /* struct flow_dissector_key_enc_opts */

I don't see the actual dissection implementation. Where is it?
Did you test the patchset?

Yes, I did test it. But it is also possible something went astray along the
way and I will retest.

I think that the code you are looking for is in
fl_classify() in this patch.

The dissection should be done in the flow_dissector. That's the whole
point in having it generic. You should move it there.

Coming back to this after lunch, I believe what I have done in this patch
is consistent with handling of other enc fields, which are set in
fl_classify() rather than the dissector. In particular the ip_tunnel_info,
which is used by this patch, is already used in fl_classify().

That means the current code is wrong. The dissection should be done in
flow_dissector, not in fl_classify.

Without this patch I see:


static int fl_classify(struct sk_buff *skb, const struct tcf_proto *tp,
                      struct tcf_result *res)
{
       ...
       struct ip_tunnel_info *info;

       ...

       info = skb_tunnel_info(skb);
       if (info) {
               struct ip_tunnel_key *key = &info->key;

               switch (ip_tunnel_info_af(info)) {
               case AF_INET:
                       skb_key.enc_control.addr_type =
                               FLOW_DISSECTOR_KEY_IPV4_ADDRS;
                       skb_key.enc_ipv4.src = key->u.ipv4.src;
                       skb_key.enc_ipv4.dst = key->u.ipv4.dst;
                       break;
               case AF_INET6:
                       skb_key.enc_control.addr_type =
                               FLOW_DISSECTOR_KEY_IPV6_ADDRS;
                       skb_key.enc_ipv6.src = key->u.ipv6.src;
                       skb_key.enc_ipv6.dst = key->u.ipv6.dst;
                       break;
               }

               skb_key.enc_key_id.keyid = tunnel_id_to_key32(key->tun_id);
               skb_key.enc_tp.src = key->tp_src;
               skb_key.enc_tp.dst = key->tp_dst;
       }

...
}

This patch adds the following inside the if() clause above:

if (info->options_len) {
	skb_key.enc_opts.len = info->options_len;
	ip_tunnel_info_opts_get(skb_key.enc_opts.data, info);
}