From 9f593653742d1dd816c4e94c6e5154a57ccba6d1 Mon Sep 17 00:00:00 2001 From: Stephen Hemminger Date: Mon, 18 Aug 2008 21:32:32 -0700 Subject: nf_nat: use secure_ipv4_port_ephemeral() for NAT port randomization Use incoming network tuple as seed for NAT port randomization. This avoids concerns of leaking net_random() bits, and also gives better port distribution. Don't have NAT server, compile tested only. Signed-off-by: Stephen Hemminger [ added missing EXPORT_SYMBOL_GPL ] Signed-off-by: Patrick McHardy Signed-off-by: David S. Miller --- net/ipv4/netfilter/nf_nat_proto_common.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'net/ipv4') diff --git a/net/ipv4/netfilter/nf_nat_proto_common.c b/net/ipv4/netfilter/nf_nat_proto_common.c index 91537f11273..6c4f11f5144 100644 --- a/net/ipv4/netfilter/nf_nat_proto_common.c +++ b/net/ipv4/netfilter/nf_nat_proto_common.c @@ -73,9 +73,13 @@ bool nf_nat_proto_unique_tuple(struct nf_conntrack_tuple *tuple, range_size = ntohs(range->max.all) - min + 1; } - off = *rover; if (range->flags & IP_NAT_RANGE_PROTO_RANDOM) - off = net_random(); + off = secure_ipv4_port_ephemeral(tuple->src.u3.ip, tuple->dst.u3.ip, + maniptype == IP_NAT_MANIP_SRC + ? tuple->dst.u.all + : tuple->src.u.all); + else + off = *rover; for (i = 0; i < range_size; i++, off++) { *portptr = htons(min + off % range_size); -- cgit