bpf: sync bpf.h to tools and update bpf_helpers.h

This patch syncs the uapi bpf.h to tools/ and also updates
bpf_herlpers.h in tools/
Signed-off-by: Lawrence Brakmo <brakmo@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

tools/include/uapi/linux/bpf.h

@@ -2359,6 +2359,13 @@ union bpf_attr {
  *	Return
  *		A **struct bpf_tcp_sock** pointer on success, or NULL in
  *		case of failure.
+ *
+ * int bpf_skb_ecn_set_ce(struct sk_buf *skb)
+ *     Description
+ *             Sets ECN of IP header to ce (congestion encountered) if
+ *             current value is ect (ECN capable). Works with IPv6 and IPv4.
+ *     Return
+ *             1 if set, 0 if not set.
  */
 #define __BPF_FUNC_MAPPER(FN)		\
 	FN(unspec),			\
@@ -2457,7 +2464,8 @@ union bpf_attr {
 	FN(spin_lock),			\
 	FN(spin_unlock),		\
 	FN(sk_fullsock),		\
-	FN(tcp_sock),
+	FN(tcp_sock),			\
+	FN(skb_ecn_set_ce),
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
  * function eBPF program intends to call

tools/testing/selftests/bpf/bpf_helpers.h

@@ -180,6 +180,8 @@ static struct bpf_sock *(*bpf_sk_fullsock)(struct bpf_sock *sk) =
 	(void *) BPF_FUNC_sk_fullsock;
 static struct bpf_tcp_sock *(*bpf_tcp_sock)(struct bpf_sock *sk) =
 	(void *) BPF_FUNC_tcp_sock;
+static int (*bpf_skb_ecn_set_ce)(void *ctx) =
+	(void *) BPF_FUNC_skb_ecn_set_ce;
 
 /* llvm builtin functions that eBPF C program may use to
  * emit BPF_LD_ABS and BPF_LD_IND instructions