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authorStephen Hemminger <shemminger@vyatta.com>2008-08-18 21:32:32 -0700
committerDavid S. Miller <davem@davemloft.net>2008-08-18 21:32:32 -0700
commit9f593653742d1dd816c4e94c6e5154a57ccba6d1 (patch)
tree1e71181cc80da8dc3d6e1da202943482b9eb5500
parentfab00c5d15091546be681426c60b2ed2c10513bf (diff)
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 <shemminger@vyatta.com> [ added missing EXPORT_SYMBOL_GPL ] Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--drivers/char/random.c1
-rw-r--r--net/ipv4/netfilter/nf_nat_proto_common.c8
2 files changed, 7 insertions, 2 deletions
diff --git a/drivers/char/random.c b/drivers/char/random.c
index e0d0e371909c..1838aa3d24fe 100644
--- a/drivers/char/random.c
+++ b/drivers/char/random.c
@@ -1571,6 +1571,7 @@ u32 secure_ipv4_port_ephemeral(__be32 saddr, __be32 daddr, __be16 dport)
return half_md4_transform(hash, keyptr->secret);
}
+EXPORT_SYMBOL_GPL(secure_ipv4_port_ephemeral);
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
u32 secure_ipv6_port_ephemeral(const __be32 *saddr, const __be32 *daddr,
diff --git a/net/ipv4/netfilter/nf_nat_proto_common.c b/net/ipv4/netfilter/nf_nat_proto_common.c
index 91537f11273f..6c4f11f51446 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);

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