From 7001c6d109ea41a88e7156f467cf9fb5f37f5036 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Mon, 18 Apr 2016 16:17:00 +0200 Subject: [PATCH] netfilter: conntrack: use get_random_once for nat and expectations Use a private seed and init it using get_random_once. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_conntrack_expect.c | 7 +++---- net/netfilter/nf_nat_core.c | 6 ++++-- 2 files changed, 7 insertions(+), 6 deletions(-) diff --git a/net/netfilter/nf_conntrack_expect.c b/net/netfilter/nf_conntrack_expect.c index 278927ab0948..c2f7c4f475b1 100644 --- a/net/netfilter/nf_conntrack_expect.c +++ b/net/netfilter/nf_conntrack_expect.c @@ -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); } diff --git a/net/netfilter/nf_nat_core.c b/net/netfilter/nf_nat_core.c index 06a9f45771ab..3d522715a167 100644 --- a/net/netfilter/nf_nat_core.c +++ b/net/netfilter/nf_nat_core.c @@ -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); } -- 2.20.1