[PATCH net-next 2/2] cls_flower: add support for matching MPLS fields (v2)

Benjamin LaHaise
2017-04-22T20:54:07Z

Add support to the tc flower classifier to match based on fields in MPLS
labels (TTL, Bottom of Stack, TC field, Label).

Signed-off-by: Benjamin LaHaise <benjamin.lahaise@netronome.com>
Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Simon Horman <simon.horman@netronome.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Jiri Pirko <jiri@mellanox.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Hadar Hen Zion <hadarh@mellanox.com>
Cc: Gao Feng <fgao@ikuai8.com>
---
include/uapi/linux/pkt_cls.h | 5 +++
net/sched/cls_flower.c | 74 ++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 79 insertions(+)

diff --git a/include/uapi/linux/pkt_cls.h b/include/uapi/linux/pkt_cls.h
index 7a69f2a..f1129e3 100644
--- a/include/uapi/linux/pkt_cls.h
+++ b/include/uapi/linux/pkt_cls.h
@@ -432,6 +432,11 @@ enum {
TCA_FLOWER_KEY_ARP_THA, /* ETH_ALEN */
TCA_FLOWER_KEY_ARP_THA_MASK, /* ETH_ALEN */

+ TCA_FLOWER_KEY_MPLS_TTL, /* u8 - 8 bits */
+ TCA_FLOWER_KEY_MPLS_BOS, /* u8 - 1 bit */
+ TCA_FLOWER_KEY_MPLS_TC, /* u8 - 3 bits */
+ TCA_FLOWER_KEY_MPLS_LABEL, /* be32 - 20 bits */
+
__TCA_FLOWER_MAX,
};

diff --git a/net/sched/cls_flower.c b/net/sched/cls_flower.c
index 31ee340..3ecf076 100644
--- a/net/sched/cls_flower.c
+++ b/net/sched/cls_flower.c
@@ -18,6 +18,7 @@
#include <linux/if_ether.h>
#include <linux/in6.h>
#include <linux/ip.h>
+#include <linux/mpls.h>

#include <net/sch_generic.h>
#include <net/pkt_cls.h>
@@ -47,6 +48,7 @@ struct fl_flow_key {
struct flow_dissector_key_ipv6_addrs enc_ipv6;
};
struct flow_dissector_key_ports enc_tp;
+ struct flow_dissector_key_mpls mpls;
} __aligned(BITS_PER_LONG / 8); /* Ensure that we can do comparisons as longs. */

struct fl_flow_mask_range {
@@ -418,6 +420,10 @@ static const struct nla_policy fl_policy[TCA_FLOWER_MAX + 1] = {
[TCA_FLOWER_KEY_ARP_SHA_MASK] = { .len = ETH_ALEN },
[TCA_FLOWER_KEY_ARP_THA] = { .len = ETH_ALEN },
[TCA_FLOWER_KEY_ARP_THA_MASK] = { .len = ETH_ALEN },
+ [TCA_FLOWER_KEY_MPLS_TTL] = { .type = NLA_U8 },
+ [TCA_FLOWER_KEY_MPLS_BOS] = { .type = NLA_U8 },
+ [TCA_FLOWER_KEY_MPLS_TC] = { .type = NLA_U8 },
+ [TCA_FLOWER_KEY_MPLS_LABEL] = { .type = NLA_U32 },
};

static void fl_set_key_val(struct nlattr **tb,
@@ -433,6 +439,31 @@ static void fl_set_key_val(struct nlattr **tb,
memcpy(mask, nla_data(tb[mask_type]), len);
}

+static void fl_set_key_mpls(struct nlattr **tb,
+ struct flow_dissector_key_mpls *key_val,
+ struct flow_dissector_key_mpls *key_mask)
+{
+ if (tb[TCA_FLOWER_KEY_MPLS_TTL]) {
+ key_val->mpls_ttl = nla_get_u8(tb[TCA_FLOWER_KEY_MPLS_TTL]);
+ key_mask->mpls_ttl = MPLS_TTL_MASK;
+ }
+ if (tb[TCA_FLOWER_KEY_MPLS_BOS]) {
+ key_val->mpls_bos = nla_get_u8(tb[TCA_FLOWER_KEY_MPLS_BOS]);
+ key_mask->mpls_bos = MPLS_BOS_MASK;
+ }
+ if (tb[TCA_FLOWER_KEY_MPLS_TC]) {
+ key_val->mpls_tc =
+ nla_get_u8(tb[TCA_FLOWER_KEY_MPLS_TC]) & MPLS_TC_MASK;
+ key_mask->mpls_tc = MPLS_TC_MASK;
+ }
+ if (tb[TCA_FLOWER_KEY_MPLS_LABEL]) {
+ key_val->mpls_label =
+ nla_get_u32(tb[TCA_FLOWER_KEY_MPLS_LABEL]) &
+ MPLS_LABEL_MASK;
+ key_mask->mpls_label = MPLS_LABEL_MASK;
+ }
+}
+
static void fl_set_key_vlan(struct nlattr **tb,
struct flow_dissector_key_vlan *key_val,
struct flow_dissector_key_vlan *key_mask)
@@ -589,6 +620,9 @@ static int fl_set_key(struct net *net, struct nlattr **tb,
&mask->icmp.code,
TCA_FLOWER_KEY_ICMPV6_CODE_MASK,
sizeof(key->icmp.code));
+ } else if (key->basic.n_proto == htons(ETH_P_MPLS_UC) ||
+ key->basic.n_proto == htons(ETH_P_MPLS_MC)) {
+ fl_set_key_mpls(tb, &key->mpls, &mask->mpls);
} else if (key->basic.n_proto == htons(ETH_P_ARP) ||
key->basic.n_proto == htons(ETH_P_RARP)) {
fl_set_key_val(tb, &key->arp.sip, TCA_FLOWER_KEY_ARP_SIP,
@@ -725,6 +759,8 @@ static void fl_init_dissector(struct cls_fl_head *head,
FL_KEY_SET_IF_MASKED(&mask->key, keys, cnt,
FLOW_DISSECTOR_KEY_ARP, arp);
FL_KEY_SET_IF_MASKED(&mask->key, keys, cnt,
+ FLOW_DISSECTOR_KEY_MPLS, mpls);
+ FL_KEY_SET_IF_MASKED(&mask->key, keys, cnt,
FLOW_DISSECTOR_KEY_VLAN, vlan);
FL_KEY_SET_IF_MASKED(&mask->key, keys, cnt,
FLOW_DISSECTOR_KEY_ENC_KEYID, enc_key_id);
@@ -991,6 +1027,41 @@ static int fl_dump_key_val(struct sk_buff *skb,
return 0;
}

+static int fl_dump_key_mpls(struct sk_buff *skb,
+ struct flow_dissector_key_mpls *mpls_key,
+ struct flow_dissector_key_mpls *mpls_mask)
+{
+ int err;
+
+ if (!memchr_inv(mpls_mask, 0, sizeof(*mpls_mask)))
+ return 0;
+ if (mpls_mask->mpls_ttl) {
+ err = nla_put_u8(skb, TCA_FLOWER_KEY_MPLS_TTL,
+ mpls_key->mpls_ttl);
+ if (err)
+ return err;
+ }
+ if (mpls_mask->mpls_tc) {
+ err = nla_put_u8(skb, TCA_FLOWER_KEY_MPLS_TC,
+ mpls_key->mpls_tc);
+ if (err)
+ return err;
+ }
+ if (mpls_mask->mpls_label) {
+ err = nla_put_u32(skb, TCA_FLOWER_KEY_MPLS_LABEL,
+ mpls_key->mpls_label);
+ if (err)
+ return err;
+ }
+ if (mpls_mask->mpls_bos) {
+ err = nla_put_u8(skb, TCA_FLOWER_KEY_MPLS_BOS,
+ mpls_key->mpls_bos);
+ if (err)
+ return err;
+ }
+ return 0;
+}
+
static int fl_dump_key_vlan(struct sk_buff *skb,
struct flow_dissector_key_vlan *vlan_key,
struct flow_dissector_key_vlan *vlan_mask)
@@ -1096,6 +1167,9 @@ static int fl_dump(struct net *net, struct tcf_proto *tp, unsigned long fh,
sizeof(key->basic.n_proto)))
goto nla_put_failure;

+ if (fl_dump_key_mpls(skb, &key->mpls, &mask->mpls))
+ goto nla_put_failure;
+
if (fl_dump_key_vlan(skb, &key->vlan, &mask->vlan))
goto nla_put_failure;

--
2.7.4