From 64f0f5d18a47c703c85576375cc010e83dac6a48 Mon Sep 17 00:00:00 2001 From: Paolo Abeni Date: Fri, 25 Aug 2017 14:31:01 +0200 Subject: udp6: set rx_dst_cookie on rx_dst updates Currently, in the udp6 code, the dst cookie is not initialized/updated concurrently with the RX dst used by early demux. As a result, the dst_check() in the early_demux path always fails, the rx dst cache is always invalidated, and we can't really leverage significant gain from the demux lookup. Fix it adding udp6 specific variant of sk_rx_dst_set() and use it to set the dst cookie when the dst entry is really changed. The issue is there since the introduction of early demux for ipv6. Fixes: 5425077d73e0 ("net: ipv6: Add early demux handler for UDP unicast") Acked-by: Hannes Frederic Sowa Signed-off-by: Paolo Abeni Signed-off-by: David S. Miller --- net/ipv4/udp.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'net/ipv4/udp.c') diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index cd1d044a7fa5..a6dc48d76a29 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -1929,14 +1929,16 @@ drop: /* For TCP sockets, sk_rx_dst is protected by socket lock * For UDP, we use xchg() to guard against concurrent changes. */ -void udp_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst) +bool udp_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst) { struct dst_entry *old; if (dst_hold_safe(dst)) { old = xchg(&sk->sk_rx_dst, dst); dst_release(old); + return old != dst; } + return false; } EXPORT_SYMBOL(udp_sk_rx_dst_set); -- cgit v1.2.3