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

Simon Horman
2017-09-27T08:16:56Z

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 <simon.horman@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>

---
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 */

FLOW_DISSECTOR_KEY_MAX,
};
diff --git a/include/uapi/linux/pkt_cls.h b/include/uapi/linux/pkt_cls.h
index d5e2bf68d0d4..7a09a28f21e0 100644
--- a/include/uapi/linux/pkt_cls.h
+++ b/include/uapi/linux/pkt_cls.h
@@ -467,6 +467,9 @@ enum {
TCA_FLOWER_KEY_IP_TTL, /* u8 */
TCA_FLOWER_KEY_IP_TTL_MASK, /* u8 */

+ TCA_FLOWER_KEY_ENC_OPTS,
+ TCA_FLOWER_KEY_ENC_OPTS_MASK,
+
__TCA_FLOWER_MAX,
};

diff --git a/net/sched/cls_flower.c b/net/sched/cls_flower.c
index d230cb4c8094..e72a17c46f07 100644
--- a/net/sched/cls_flower.c
+++ b/net/sched/cls_flower.c
@@ -51,6 +51,7 @@ struct fl_flow_key {
struct flow_dissector_key_mpls mpls;
struct flow_dissector_key_tcp tcp;
struct flow_dissector_key_ip ip;
+ struct flow_dissector_key_enc_opts enc_opts;
} __aligned(BITS_PER_LONG / 8); /* Ensure that we can do comparisons as longs. */

struct fl_flow_mask_range {
@@ -181,6 +182,11 @@ static int fl_classify(struct sk_buff *skb, const struct tcf_proto *tp,
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;
+
+ if (info->options_len) {
+ skb_key.enc_opts.len = info->options_len;
+ ip_tunnel_info_opts_get(skb_key.enc_opts.data, info);
+ }
}

skb_key.indev_ifindex = skb->skb_iif;
@@ -421,6 +427,8 @@ static const struct nla_policy fl_policy[TCA_FLOWER_MAX + 1] = {
[TCA_FLOWER_KEY_IP_TOS_MASK] = { .type = NLA_U8 },
[TCA_FLOWER_KEY_IP_TTL] = { .type = NLA_U8 },
[TCA_FLOWER_KEY_IP_TTL_MASK] = { .type = NLA_U8 },
+ [TCA_FLOWER_KEY_ENC_OPTS] = { .type = NLA_BINARY },
+ [TCA_FLOWER_KEY_ENC_OPTS_MASK] = { .type = NLA_BINARY },
};

static void fl_set_key_val(struct nlattr **tb,
@@ -712,6 +720,26 @@ static int fl_set_key(struct net *net, struct nlattr **tb,
&mask->enc_tp.dst, TCA_FLOWER_KEY_ENC_UDP_DST_PORT_MASK,
sizeof(key->enc_tp.dst));

+ if (tb[TCA_FLOWER_KEY_ENC_OPTS]) {
+ key->enc_opts.len = nla_len(tb[TCA_FLOWER_KEY_ENC_OPTS]);
+
+ if (key->enc_opts.len > sizeof(key->enc_opts.data))
+ return -EINVAL;
+
+ /* enc_opts is variable length.
+ * If present ensure the value and mask are the same length.
+ */
+ if (tb[TCA_FLOWER_KEY_ENC_OPTS_MASK] &&
+ nla_len(tb[TCA_FLOWER_KEY_ENC_OPTS_MASK]) != key->enc_opts.len)
+ return -EINVAL;
+
+ mask->enc_opts.len = key->enc_opts.len;
+ fl_set_key_val(tb, key->enc_opts.data, TCA_FLOWER_KEY_ENC_OPTS,
+ mask->enc_opts.data,
+ TCA_FLOWER_KEY_ENC_OPTS_MASK,
+ key->enc_opts.len);
+ }
+
if (tb[TCA_FLOWER_KEY_FLAGS])
ret = fl_set_key_flags(tb, &key->control.flags, &mask->control.flags);

@@ -804,6 +832,8 @@ static void fl_init_dissector(struct cls_fl_head *head,
enc_control);
FL_KEY_SET_IF_MASKED(&mask->key, keys, cnt,
FLOW_DISSECTOR_KEY_ENC_PORTS, enc_tp);
+ FL_KEY_SET_IF_MASKED(&mask->key, keys, cnt,
+ FLOW_DISSECTOR_KEY_ENC_OPTS, enc_opts);

skb_flow_dissector_init(&head->dissector, keys, cnt);
}
@@ -1330,7 +1360,10 @@ static int fl_dump(struct net *net, struct tcf_proto *tp, void *fh,
TCA_FLOWER_KEY_ENC_UDP_DST_PORT,
&mask->enc_tp.dst,
TCA_FLOWER_KEY_ENC_UDP_DST_PORT_MASK,
- sizeof(key->enc_tp.dst)))
+ sizeof(key->enc_tp.dst)) ||
+ fl_dump_key_val(skb, key->enc_opts.data, TCA_FLOWER_KEY_ENC_OPTS,
+ mask->enc_opts.data, TCA_FLOWER_KEY_ENC_OPTS_MASK,
+ key->enc_opts.len))
goto nla_put_failure;

if (fl_dump_key_flags(skb, key->control.flags, mask->control.flags))
--
2.1.4