soreuseport: fast reuseport TCP socket selection

This change extends the fast SO_REUSEPORT socket lookup implemented
for UDP to TCP.  Listener sockets with SO_REUSEPORT and the same
receive address are additionally added to an array for faster
random access.  This means that only a single socket from the group
must be found in the listener list before any socket in the group can
be used to receive a packet.  Previously, every socket in the group
needed to be considered before handing off the incoming packet.

This feature also exposes the ability to use a BPF program when
selecting a socket from a reuseport group.

Signed-off-by: Craig Gallek <kraig@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 4 insertions, 1 deletions

diff --git a/include/net/inet_hashtables.h b/include/net/inet_hashtables.h
index 82403390af58..50f635c2c536 100644
--- a/include/net/inet_hashtables.h
+++ b/include/net/inet_hashtables.h
@@ -207,7 +207,10 @@ void inet_hashinfo_init(struct inet_hashinfo *h);
 
 bool inet_ehash_insert(struct sock *sk, struct sock *osk);
 bool inet_ehash_nolisten(struct sock *sk, struct sock *osk);
-void __inet_hash(struct sock *sk, struct sock *osk);
+int __inet_hash(struct sock *sk, struct sock *osk,
+		int (*saddr_same)(const struct sock *sk1,
+				  const struct sock *sk2,
+				  bool match_wildcard));
 int inet_hash(struct sock *sk);
 void inet_unhash(struct sock *sk);