net/tcp: Add a helper tcp_ao_hdr_maclen()

It's going to be used more in TCP-AO tracepoints.

Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 5 insertions, 0 deletions

diff --git a/include/net/tcp_ao.h b/include/net/tcp_ao.h
index 5d8e9ed2c005..198e02004ad2 100644
--- a/include/net/tcp_ao.h
+++ b/include/net/tcp_ao.h
@@ -19,6 +19,11 @@ struct tcp_ao_hdr {
 	u8	rnext_keyid;
 };
 
+static inline u8 tcp_ao_hdr_maclen(const struct tcp_ao_hdr *aoh)
+{
+	return aoh->length - sizeof(struct tcp_ao_hdr);
+}
+
 struct tcp_ao_counters {
 	atomic64_t	pkt_good;
 	atomic64_t	pkt_bad;