diff options
| author | Eric Dumazet <edumazet@google.com> | 2013-02-21 12:18:52 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2013-02-21 18:15:58 -0500 |
| commit | 08dcdbf6a7b9d14c2302c5bd0c5390ddf122f664 (patch) | |
| tree | fc1d00005fda323296b93064416d255b81fdab73 /include/net/inet6_hashtables.h | |
| parent | 0ab8a9f5fa94ac625c1f19acc48db299416c6d49 (diff) | |
| download | lwn-08dcdbf6a7b9d14c2302c5bd0c5390ddf122f664.tar.gz lwn-08dcdbf6a7b9d14c2302c5bd0c5390ddf122f664.zip | |
ipv6: use a stronger hash for tcp
It looks like its possible to open thousands of TCP IPv6
sessions on a server, all landing in a single slot of TCP hash
table. Incoming packets have to lookup sockets in a very
long list.
We should hash all bits from foreign IPv6 addresses, using
a salt and hash mix, not a simple XOR.
inet6_ehashfn() can also separately use the ports, instead
of xoring them.
Reported-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/net/inet6_hashtables.h')
| -rw-r--r-- | include/net/inet6_hashtables.h | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/include/net/inet6_hashtables.h b/include/net/inet6_hashtables.h index 7ca75cbbf75e..fd4ee016ba5c 100644 --- a/include/net/inet6_hashtables.h +++ b/include/net/inet6_hashtables.h @@ -28,16 +28,16 @@ struct inet_hashinfo; -/* I have no idea if this is a good hash for v6 or not. -DaveM */ static inline unsigned int inet6_ehashfn(struct net *net, const struct in6_addr *laddr, const u16 lport, const struct in6_addr *faddr, const __be16 fport) { - u32 ports = (lport ^ (__force u16)fport); + u32 ports = (((u32)lport) << 16) | (__force u32)fport; return jhash_3words((__force u32)laddr->s6_addr32[3], - (__force u32)faddr->s6_addr32[3], - ports, inet_ehash_secret + net_hash_mix(net)); + ipv6_addr_jhash(faddr), + ports, + inet_ehash_secret + net_hash_mix(net)); } static inline int inet6_sk_ehashfn(const struct sock *sk) |