src: add nat persistent and random options

This patch adds more configuration options to the nat expression.

The syntax is as follow:
 % nft add rule nat postrouting <snat|dnat> <nat_arguments> [flags]

Flags are: random, persistent, random-fully.
Example:

 % nft add rule nat postrouting dnat 1.1.1.1 random,persistent

A requirement is to cache some [recent] copies of kernel headers.

Signed-off-by: Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

1 files changed, 42 insertions, 0 deletions

diff --git a/include/linux/netfilter/nf_nat.h b/include/linux/netfilter/nf_nat.h
new file mode 100644
index 00000000..0880781a
--- /dev/null
+++ b/include/linux/netfilter/nf_nat.h
@@ -0,0 +1,42 @@
+#ifndef _NETFILTER_NF_NAT_H
+#define _NETFILTER_NF_NAT_H
+
+#include <linux/netfilter.h>
+#include <linux/netfilter/nf_conntrack_tuple_common.h>
+
+#define NF_NAT_RANGE_MAP_IPS			(1 << 0)
+#define NF_NAT_RANGE_PROTO_SPECIFIED		(1 << 1)
+#define NF_NAT_RANGE_PROTO_RANDOM		(1 << 2)
+#define NF_NAT_RANGE_PERSISTENT			(1 << 3)
+#define NF_NAT_RANGE_PROTO_RANDOM_FULLY		(1 << 4)
+
+#define NF_NAT_RANGE_PROTO_RANDOM_ALL		\
+	(NF_NAT_RANGE_PROTO_RANDOM | NF_NAT_RANGE_PROTO_RANDOM_FULLY)
+
+#define NF_NAT_RANGE_MASK					\
+	(NF_NAT_RANGE_MAP_IPS | NF_NAT_RANGE_PROTO_SPECIFIED |	\
+	 NF_NAT_RANGE_PROTO_RANDOM | NF_NAT_RANGE_PERSISTENT |	\
+	 NF_NAT_RANGE_PROTO_RANDOM_FULLY)
+
+struct nf_nat_ipv4_range {
+	unsigned int			flags;
+	__be32				min_ip;
+	__be32				max_ip;
+	union nf_conntrack_man_proto	min;
+	union nf_conntrack_man_proto	max;
+};
+
+struct nf_nat_ipv4_multi_range_compat {
+	unsigned int			rangesize;
+	struct nf_nat_ipv4_range	range[1];
+};
+
+struct nf_nat_range {
+	unsigned int			flags;
+	union nf_inet_addr		min_addr;
+	union nf_inet_addr		max_addr;
+	union nf_conntrack_man_proto	min_proto;
+	union nf_conntrack_man_proto	max_proto;
+};
+
+#endif /* _NETFILTER_NF_NAT_H */