Merge branch 'sk_txhash'

Tom Herbert says:

====================
net: Initialize sk_hash to random value and reset for failing cnxs

This patch set implements a common function to simply set sk_txhash to
a random number instead of going through the trouble to call flow
dissector. From dst_negative_advice we now reset the sk_txhash in hopes
of finding a better ECMP path through the network. Changing sk_txhash
affects:
  - IPv6 flow label and UDP source port which affect ECMP in the network
  - Local ECMP route selection (pending changes to use sk_txhash)
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 16 insertions, 0 deletions

diff --git a/include/net/sock.h b/include/net/sock.h
index 4353ef70bf48..24aa75c5317a 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -1687,6 +1687,20 @@ static inline void sock_graft(struct sock *sk, struct socket *parent)
 kuid_t sock_i_uid(struct sock *sk);
 unsigned long sock_i_ino(struct sock *sk);
 
+static inline void sk_set_txhash(struct sock *sk)
+{
+	sk->sk_txhash = prandom_u32();
+
+	if (unlikely(!sk->sk_txhash))
+		sk->sk_txhash = 1;
+}
+
+static inline void sk_rethink_txhash(struct sock *sk)
+{
+	if (sk->sk_txhash)
+		sk_set_txhash(sk);
+}
+
 static inline struct dst_entry *
 __sk_dst_get(struct sock *sk)
 {
@@ -1711,6 +1725,8 @@ static inline void dst_negative_advice(struct sock *sk)
 {
 	struct dst_entry *ndst, *dst = __sk_dst_get(sk);
 
+	sk_rethink_txhash(sk);
+
 	if (dst && dst->ops->negative_advice) {
 		ndst = dst->ops->negative_advice(dst);