From mboxrd@z Thu Jan 1 00:00:00 1970 From: pablo@netfilter.org Subject: [PATCH 11/19] netfilter: nf_nat: use hash random for bysource hash Date: Sun, 25 Dec 2011 02:57:27 +0100 Message-ID: <1324778255-2830-12-git-send-email-pablo@netfilter.org> References: <1324778255-2830-1-git-send-email-pablo@netfilter.org> Cc: davem@davemloft.net, netdev@vger.kernel.org To: netfilter-devel@vger.kernel.org Return-path: Received: from mail.us.es ([193.147.175.20]:56012 "EHLO mail.us.es" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758028Ab1LYB6J (ORCPT ); Sat, 24 Dec 2011 20:58:09 -0500 In-Reply-To: <1324778255-2830-1-git-send-email-pablo@netfilter.org> Sender: netfilter-devel-owner@vger.kernel.org List-ID: From: Patrick McHardy Use nf_conntrack_hash_rnd in NAT bysource hash to avoid hash chain attacks. Signed-off-by: Patrick McHardy Acked-by: Eric Dumazet Signed-off-by: Pablo Neira Ayuso --- net/ipv4/netfilter/nf_nat_core.c | 2 +- net/netfilter/nf_conntrack_core.c | 1 + 2 files changed, 2 insertions(+), 1 deletions(-) diff --git a/net/ipv4/netfilter/nf_nat_core.c b/net/ipv4/netfilter/nf_nat_core.c index 58ab7a4..76600f8 100644 --- a/net/ipv4/netfilter/nf_nat_core.c +++ b/net/ipv4/netfilter/nf_nat_core.c @@ -57,7 +57,7 @@ hash_by_src(const struct net *net, u16 zone, /* Original src, to ensure we map it consistently if poss. */ hash = jhash_3words((__force u32)tuple->src.u3.ip, (__force u32)tuple->src.u.all ^ zone, - tuple->dst.protonum, 0); + tuple->dst.protonum, nf_conntrack_hash_rnd); return ((u64)hash * net->ipv4.nat_htable_size) >> 32; } diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c index 8b2842e..b76090f 100644 --- a/net/netfilter/nf_conntrack_core.c +++ b/net/netfilter/nf_conntrack_core.c @@ -67,6 +67,7 @@ DEFINE_PER_CPU(struct nf_conn, nf_conntrack_untracked); EXPORT_PER_CPU_SYMBOL(nf_conntrack_untracked); unsigned int nf_conntrack_hash_rnd __read_mostly; +EXPORT_SYMBOL_GPL(nf_conntrack_hash_rnd); static u32 hash_conntrack_raw(const struct nf_conntrack_tuple *tuple, u16 zone) { -- 1.7.2.5