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| author | Eric Dumazet <edumazet@google.com> | 2013-02-21 12:18:52 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-02-28 06:59:06 -0800 |
| commit | e5a096aa0aeb1fc8ad8b3d6bd70d322a0d65edc4 (patch) | |
| tree | d5055028b4ac0b56b49b6d65237038c5c7f46778 /include/net/ipv6.h | |
| parent | 785e5dce256ea5bdf4871af13f9908b74264b515 (diff) | |
| download | linux-3.10-e5a096aa0aeb1fc8ad8b3d6bd70d322a0d65edc4.tar.gz linux-3.10-e5a096aa0aeb1fc8ad8b3d6bd70d322a0d65edc4.tar.bz2 linux-3.10-e5a096aa0aeb1fc8ad8b3d6bd70d322a0d65edc4.zip | |
ipv6: use a stronger hash for tcp
[ Upstream commit 08dcdbf6a7b9d14c2302c5bd0c5390ddf122f664 ]
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include/net/ipv6.h')
| -rw-r--r-- | include/net/ipv6.h | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/include/net/ipv6.h b/include/net/ipv6.h index e4170a22fc6..12a1bd2e987 100644 --- a/include/net/ipv6.h +++ b/include/net/ipv6.h @@ -15,6 +15,7 @@ #include <linux/ipv6.h> #include <linux/hardirq.h> +#include <linux/jhash.h> #include <net/if_inet6.h> #include <net/ndisc.h> #include <net/flow.h> @@ -390,6 +391,17 @@ struct ip6_create_arg { void ip6_frag_init(struct inet_frag_queue *q, void *a); int ip6_frag_match(struct inet_frag_queue *q, void *a); +/* more secured version of ipv6_addr_hash() */ +static inline u32 ipv6_addr_jhash(const struct in6_addr *a) +{ + u32 v = (__force u32)a->s6_addr32[0] ^ (__force u32)a->s6_addr32[1]; + + return jhash_3words(v, + (__force u32)a->s6_addr32[2], + (__force u32)a->s6_addr32[3], + ipv6_hash_secret); +} + static inline int ipv6_addr_any(const struct in6_addr *a) { return (a->s6_addr32[0] | a->s6_addr32[1] | |