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

From: Simon Horman <[email-masked]>
Date: Wed, 27 Sep 2017 11:27:33 +0200

On Wed, Sep 27, 2017 at 11:10:05AM +0200, Jiri Pirko wrote:
> Wed, Sep 27, 2017 at 10:16:34AM CEST, [email-masked] wrote:
> >Allow matching on options in tunnel headers.
> >This makes use of existing tunnel metadata support.
> >
> >Options are a bytestring of up to 256 bytes.
> >Tunnel implementations may support less or more options,
> >or no options at all.
> >
> >e.g.
> > # ip link add name geneve0 type geneve dstport 0 external
> > # tc qdisc add dev geneve0 ingress
> > # tc filter add dev geneve0 protocol ip parent ffff: \
> >     flower \
> >       enc_src_ip 10.0.99.192 \
> >       enc_dst_ip 10.0.99.193 \
> >       enc_key_id 11 \
> >       enc_opts 0102800100800020/fffffffffffffff0 \
> >       ip_proto udp \
> >       action mirred egress redirect dev eth1
> >
> >Signed-off-by: Simon Horman <[email-masked]>
> >Reviewed-by: Jakub Kicinski <[email-masked]>
> >
> >---
> >v2
> >* Correct example which was incorrectly described setting rather
> >  than matching tunnel options
> >---
> > include/net/flow_dissector.h | 13 +++++++++++++
> > include/uapi/linux/pkt_cls.h |  3 +++
> > net/sched/cls_flower.c       | 35 ++++++++++++++++++++++++++++++++++-
> > 3 files changed, 50 insertions(+), 1 deletion(-)
> >
> >diff --git a/include/net/flow_dissector.h b/include/net/flow_dissector.h
> >index fc3dce730a6b..43f98bf0b349 100644
> >--- a/include/net/flow_dissector.h
> >+++ b/include/net/flow_dissector.h
> >@@ -183,6 +183,18 @@ struct flow_dissector_key_ip {
> > 	__u8	ttl;
> > };
> > 
> >+/**
> >+ * struct flow_dissector_key_enc_opts:
> >+ * @data: data
> >+ * @len: len
> >+ */
> >+struct flow_dissector_key_enc_opts {
> >+	u8 data[256];	/* Using IP_TUNNEL_OPTS_MAX is desired here
> >+			 * but seems difficult to #include
> >+			 */
> >+	u8 len;
> >+};
> >+
> > 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.