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, 2 insertions, 2 deletions

diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index be0b21852b13..ac3cedb25a9f 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -356,8 +356,8 @@ EXPORT_SYMBOL(udp_lib_get_port);
  * match_wildcard == false: addresses must be exactly the same, i.e.
  *                          0.0.0.0 only equals to 0.0.0.0
  */
-static int ipv4_rcv_saddr_equal(const struct sock *sk1, const struct sock *sk2,
-				bool match_wildcard)
+int ipv4_rcv_saddr_equal(const struct sock *sk1, const struct sock *sk2,
+			 bool match_wildcard)
 {
 	struct inet_sock *inet1 = inet_sk(sk1), *inet2 = inet_sk(sk2);