[PATCH 05/36] netfilter: conntrack: use get_random_once for nat and expectations
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STALE3821d
From: Pablo Neira Ayuso <pablo@netfilter.org>
Date: 2016-05-09 18:47:09
Also in:
netfilter-devel
Subsystem:
netfilter, networking [general], the rest · Maintainers:
Pablo Neira Ayuso, Florian Westphal, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
From: Florian Westphal <fw@strlen.de> 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> --- 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 278927a..c2f7c4f 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 06a9f45..3d52271 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); }
--
2.1.4