[PATCH nf-next] netfilter: conntrack: use siphash_4u64

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This function is used for every packet. siphash_4u64 is
about 25% faster compared to buffer+memset+siphash_unaligned as
reported by perf-diff.

Signed-off-by: Florian Westphal <fw@xxxxxxxxx>
---
 net/netfilter/nf_conntrack_core.c | 31 +++++++++++++------------------
 1 file changed, 13 insertions(+), 18 deletions(-)

diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index f97bda06d2a9..48c0c146cef1 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -211,28 +211,23 @@ static u32 hash_conntrack_raw(const struct nf_conntrack_tuple *tuple,
 			      unsigned int zoneid,
 			      const struct net *net)
 {
-	struct {
-		struct nf_conntrack_man src;
-		union nf_inet_addr dst_addr;
-		unsigned int zone;
-		u32 net_mix;
-		u16 dport;
-		u16 proto;
-	} __aligned(SIPHASH_ALIGNMENT) combined;
+	u64 a, b, c, d;
 
 	get_random_once(&nf_conntrack_hash_rnd, sizeof(nf_conntrack_hash_rnd));
 
-	memset(&combined, 0, sizeof(combined));
-
 	/* The direction must be ignored, so handle usable members manually. */
-	combined.src = tuple->src;
-	combined.dst_addr = tuple->dst.u3;
-	combined.zone = zoneid;
-	combined.net_mix = net_hash_mix(net);
-	combined.dport = (__force __u16)tuple->dst.u.all;
-	combined.proto = tuple->dst.protonum;
-
-	return (u32)siphash(&combined, sizeof(combined), &nf_conntrack_hash_rnd);
+	a = (u64)tuple->src.u3.all[0] << 32 | tuple->src.u3.all[1];
+	b = (u64)tuple->src.u3.all[2] << 32 | tuple->src.u3.all[3];
+
+	c = (u64)tuple->dst.u3.all[0] << 32 | tuple->dst.u3.all[1];
+	d = (u64)tuple->dst.u3.all[1] << 32 | tuple->dst.u3.all[2];
+
+	a ^= (__force __u64)tuple->dst.u.all;
+	b += tuple->dst.protonum;
+	c ^= net_hash_mix(net);
+	d += zoneid;
+
+	return (u32)siphash_4u64(a, b, c, d, &nf_conntrack_hash_rnd);
 }
 
 static u32 scale_hash(u32 hash)
-- 
2.37.3




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