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netfilter: conntrack: use get_random_once for nat and expectations

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Use a private seed and init it using get_random_once.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Florian Westphal 2016-04-18 16:17:00 +02:00 committed by Pablo Neira Ayuso
parent a3efd81205
commit 7001c6d109
2 changed files with 7 additions and 6 deletions
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7
net/netfilter/nf_conntrack_expect.c
View File

@ -38,6 +38,7 @@ EXPORT_SYMBOL_GPL(nf_ct_expect_hsize);
unsigned int nf_ct_expect_max __read_mostly;
static struct kmem_cache *nf_ct_expect_cachep __read_mostly;
static unsigned int nf_ct_expect_hashrnd __read_mostly;
/* nf_conntrack_expect helper functions */
void nf_ct_unlink_expect_report(struct nf_conntrack_expect *exp,
@ -76,13 +77,11 @@ static unsigned int nf_ct_expect_dst_hash(const struct nf_conntrack_tuple *tuple
{
unsigned int hash;
if (unlikely(!nf_conntrack_hash_rnd)) {
init_nf_conntrack_hash_rnd();
}
get_random_once(&nf_ct_expect_hashrnd, sizeof(nf_ct_expect_hashrnd));
hash = jhash2(tuple->dst.u3.all, ARRAY_SIZE(tuple->dst.u3.all),
(((tuple->dst.protonum ^ tuple->src.l3num) << 16) |
(__force __u16)tuple->dst.u.all) ^ nf_conntrack_hash_rnd);
(__force __u16)tuple->dst.u.all) ^ nf_ct_expect_hashrnd);
return reciprocal_scale(hash, nf_ct_expect_hsize);
}

6
net/netfilter/nf_nat_core.c
View File

@ -37,7 +37,7 @@ static const struct nf_nat_l3proto __rcu *nf_nat_l3protos[NFPROTO_NUMPROTO]
__read_mostly;
static const struct nf_nat_l4proto __rcu **nf_nat_l4protos[NFPROTO_NUMPROTO]
__read_mostly;
static unsigned int nf_nat_hash_rnd __read_mostly;
inline const struct nf_nat_l3proto *
__nf_nat_l3proto_find(u8 family)
@ -122,9 +122,11 @@ hash_by_src(const struct net *net, const struct nf_conntrack_tuple *tuple)
{
unsigned int hash;
get_random_once(&nf_nat_hash_rnd, sizeof(nf_nat_hash_rnd));
/* Original src, to ensure we map it consistently if poss. */
hash = jhash2((u32 *)&tuple->src, sizeof(tuple->src) / sizeof(u32),
tuple->dst.protonum ^ nf_conntrack_hash_rnd);
tuple->dst.protonum ^ nf_nat_hash_rnd);
return reciprocal_scale(hash, net->ct.nat_htable_size);
}