diff options
| author | Florian Westphal <fw@strlen.de> | 2012-06-04 04:53:54 +0200 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2012-06-07 14:58:42 +0200 |
| commit | 1da6dd07989869fa4f8ec1f47d610d12f96eb04d (patch) | |
| tree | cbbd5784e577c7538545f2c11d2320fbd3b543e0 | |
| parent | netfilter: nf_conntrack: add namespace support for cttimeout (diff) | |
| download | linux-1da6dd07989869fa4f8ec1f47d610d12f96eb04d.tar.xz linux-1da6dd07989869fa4f8ec1f47d610d12f96eb04d.zip | |
netfilter: NFQUEUE: don't xor src/dst ip address for load distribution
because reply packets need to go to the same nfqueue, src/dst ip
address were xor'd prior to jhash().
However, this causes bad distribution for some workloads, e.g.
flows a.b.1.{1,n} -> a.b.2.{1,n} all share the same hash value.
Avoid this by hashing both. To get same hash for replies,
first argument is the smaller address.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
| -rw-r--r-- | net/netfilter/xt_NFQUEUE.c | 28 |
1 files changed, 19 insertions, 9 deletions
diff --git a/net/netfilter/xt_NFQUEUE.c b/net/netfilter/xt_NFQUEUE.c index 95237c89607a..7babe7d68716 100644 --- a/net/netfilter/xt_NFQUEUE.c +++ b/net/netfilter/xt_NFQUEUE.c @@ -41,26 +41,36 @@ nfqueue_tg(struct sk_buff *skb, const struct xt_action_param *par) static u32 hash_v4(const struct sk_buff *skb) { const struct iphdr *iph = ip_hdr(skb); - __be32 ipaddr; /* packets in either direction go into same queue */ - ipaddr = iph->saddr ^ iph->daddr; + if (iph->saddr < iph->daddr) + return jhash_3words((__force u32)iph->saddr, + (__force u32)iph->daddr, iph->protocol, jhash_initval); - return jhash_2words((__force u32)ipaddr, iph->protocol, jhash_initval); + return jhash_3words((__force u32)iph->daddr, + (__force u32)iph->saddr, iph->protocol, jhash_initval); } #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) static u32 hash_v6(const struct sk_buff *skb) { const struct ipv6hdr *ip6h = ipv6_hdr(skb); - __be32 addr[4]; + u32 a, b, c; + + if (ip6h->saddr.s6_addr32[3] < ip6h->daddr.s6_addr32[3]) { + a = (__force u32) ip6h->saddr.s6_addr32[3]; + b = (__force u32) ip6h->daddr.s6_addr32[3]; + } else { + b = (__force u32) ip6h->saddr.s6_addr32[3]; + a = (__force u32) ip6h->daddr.s6_addr32[3]; + } - addr[0] = ip6h->saddr.s6_addr32[0] ^ ip6h->daddr.s6_addr32[0]; - addr[1] = ip6h->saddr.s6_addr32[1] ^ ip6h->daddr.s6_addr32[1]; - addr[2] = ip6h->saddr.s6_addr32[2] ^ ip6h->daddr.s6_addr32[2]; - addr[3] = ip6h->saddr.s6_addr32[3] ^ ip6h->daddr.s6_addr32[3]; + if (ip6h->saddr.s6_addr32[1] < ip6h->daddr.s6_addr32[1]) + c = (__force u32) ip6h->saddr.s6_addr32[1]; + else + c = (__force u32) ip6h->daddr.s6_addr32[1]; - return jhash2((__force u32 *)addr, ARRAY_SIZE(addr), jhash_initval); + return jhash_3words(a, b, c, jhash_initval); } #endif |