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| author | Stephen Hemminger <shemminger@vyatta.com> | 2008-08-19 06:32:32 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2008-08-19 06:32:32 +0200 |
| commit | 9f593653742d1dd816c4e94c6e5154a57ccba6d1 (patch) | |
| tree | 1e71181cc80da8dc3d6e1da202943482b9eb5500 | |
| parent | netfilter: ctnetlink: sleepable allocation with spin lock bh (diff) | |
| download | linux-9f593653742d1dd816c4e94c6e5154a57ccba6d1.tar.xz linux-9f593653742d1dd816c4e94c6e5154a57ccba6d1.zip | |
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.c | 1 | ||||
| -rw-r--r-- | net/ipv4/netfilter/nf_nat_proto_common.c | 8 |
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); |