net/sched: flower: add support for matching on tcp flags

Benefit from the support of tcp flags dissection and allow user to
insert rules matching on tcp flags.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/uapi/linux/pkt_cls.h

@@ -451,6 +451,9 @@ enum {
 	TCA_FLOWER_KEY_MPLS_TC,		/* u8 - 3 bits */
 	TCA_FLOWER_KEY_MPLS_LABEL,	/* be32 - 20 bits */
 
+	TCA_FLOWER_KEY_TCP_FLAGS,	/* be16 */
+	TCA_FLOWER_KEY_TCP_FLAGS_MASK,	/* be16 */
+
 	__TCA_FLOWER_MAX,
 };
 

net/sched/cls_flower.c

@@ -49,6 +49,7 @@ struct fl_flow_key {
 	};
 	struct flow_dissector_key_ports enc_tp;
 	struct flow_dissector_key_mpls mpls;
+	struct flow_dissector_key_tcp tcp;
 } __aligned(BITS_PER_LONG / 8); /* Ensure that we can do comparisons as longs. */
 
 struct fl_flow_mask_range {
@@ -424,6 +425,8 @@ static const struct nla_policy fl_policy[TCA_FLOWER_MAX + 1] = {
 	[TCA_FLOWER_KEY_MPLS_BOS]	= { .type = NLA_U8 },
 	[TCA_FLOWER_KEY_MPLS_TC]	= { .type = NLA_U8 },
 	[TCA_FLOWER_KEY_MPLS_LABEL]	= { .type = NLA_U32 },
+	[TCA_FLOWER_KEY_TCP_FLAGS]	= { .type = NLA_U16 },
+	[TCA_FLOWER_KEY_TCP_FLAGS_MASK]	= { .type = NLA_U16 },
 };
 
 static void fl_set_key_val(struct nlattr **tb,
@@ -596,6 +599,9 @@ static int fl_set_key(struct net *net, struct nlattr **tb,
 		fl_set_key_val(tb, &key->tp.dst, TCA_FLOWER_KEY_TCP_DST,
 			       &mask->tp.dst, TCA_FLOWER_KEY_TCP_DST_MASK,
 			       sizeof(key->tp.dst));
+		fl_set_key_val(tb, &key->tcp.flags, TCA_FLOWER_KEY_TCP_FLAGS,
+			       &mask->tcp.flags, TCA_FLOWER_KEY_TCP_FLAGS_MASK,
+			       sizeof(key->tcp.flags));
 	} else if (key->basic.ip_proto == IPPROTO_UDP) {
 		fl_set_key_val(tb, &key->tp.src, TCA_FLOWER_KEY_UDP_SRC,
 			       &mask->tp.src, TCA_FLOWER_KEY_UDP_SRC_MASK,
@@ -766,6 +772,8 @@ static void fl_init_dissector(struct cls_fl_head *head,
 			     FLOW_DISSECTOR_KEY_IPV6_ADDRS, ipv6);
 	FL_KEY_SET_IF_MASKED(&mask->key, keys, cnt,
 			     FLOW_DISSECTOR_KEY_PORTS, tp);
+	FL_KEY_SET_IF_MASKED(&mask->key, keys, cnt,
+			     FLOW_DISSECTOR_KEY_TCP, tcp);
 	FL_KEY_SET_IF_MASKED(&mask->key, keys, cnt,
 			     FLOW_DISSECTOR_KEY_ICMP, icmp);
 	FL_KEY_SET_IF_MASKED(&mask->key, keys, cnt,
@@ -1215,7 +1223,10 @@ static int fl_dump(struct net *net, struct tcf_proto *tp, unsigned long fh,
 			     sizeof(key->tp.src)) ||
 	     fl_dump_key_val(skb, &key->tp.dst, TCA_FLOWER_KEY_TCP_DST,
 			     &mask->tp.dst, TCA_FLOWER_KEY_TCP_DST_MASK,
-			     sizeof(key->tp.dst))))
+			     sizeof(key->tp.dst)) ||
+	     fl_dump_key_val(skb, &key->tcp.flags, TCA_FLOWER_KEY_TCP_FLAGS,
+			     &mask->tcp.flags, TCA_FLOWER_KEY_TCP_FLAGS_MASK,
+			     sizeof(key->tcp.flags))))
 		goto nla_put_failure;
 	else if (key->basic.ip_proto == IPPROTO_UDP &&
 		 (fl_dump_key_val(skb, &key->tp.src, TCA_FLOWER_KEY_UDP_SRC,