tcp: md5: add tcp_md5_needed jump label
Most linux hosts never setup TCP MD5 keys. We can avoid a
cache line miss (accessing tp->md5ig_info) on RX and TX
using a jump label.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 3b52225..0681afc 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -1555,9 +1555,21 @@ struct tcp_md5sig_key *tcp_v4_md5_lookup(const struct sock *sk,
const struct sock *addr_sk);
#ifdef CONFIG_TCP_MD5SIG
-struct tcp_md5sig_key *tcp_md5_do_lookup(const struct sock *sk,
- const union tcp_md5_addr *addr,
- int family);
+#include <linux/jump_label.h>
+extern struct static_key tcp_md5_needed;
+struct tcp_md5sig_key *__tcp_md5_do_lookup(const struct sock *sk,
+ const union tcp_md5_addr *addr,
+ int family);
+static inline struct tcp_md5sig_key *
+tcp_md5_do_lookup(const struct sock *sk,
+ const union tcp_md5_addr *addr,
+ int family)
+{
+ if (!static_key_false(&tcp_md5_needed))
+ return NULL;
+ return __tcp_md5_do_lookup(sk, addr, family);
+}
+
#define tcp_twsk_md5_key(twsk) ((twsk)->tw_md5_key)
#else
static inline struct tcp_md5sig_key *tcp_md5_do_lookup(const struct sock *sk,
