netfilter: ipset: support range for IPv4 at adding/deleting elements for hash:*net* types

The range internally is converted to the network(s) equal to the range.
Example:

	# ipset new test hash:net
	# ipset add test 10.2.0.0-10.2.1.12
	# ipset list test
	Name: test
	Type: hash:net
	Header: family inet hashsize 1024 maxelem 65536
	Size in memory: 16888
	References: 0
	Members:
	10.2.1.12
	10.2.1.0/29
	10.2.0.0/24
	10.2.1.8/30

Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Patrick McHardy <kaber@trash.net>

include/linux/netfilter/ipset/ip_set.h

@@ -104,6 +104,7 @@ enum {
 	IPSET_ATTR_NAMEREF,
 	IPSET_ATTR_IP2,
 	IPSET_ATTR_CIDR2,
+	IPSET_ATTR_IP2_TO,
 	__IPSET_ATTR_ADT_MAX,
 };
 #define IPSET_ATTR_ADT_MAX	(__IPSET_ATTR_ADT_MAX - 1)

include/linux/netfilter/ipset/ip_set_ahash.h

@@ -353,7 +353,7 @@ retry:
 	return 0;
 }
 
-static inline void
+static void
 type_pf_data_next(struct ip_set_hash *h, const struct type_pf_elem *d);
 
 /* Add an element to a hash and update the internal counters when succeeded,

include/linux/netfilter/ipset/ip_set_hash.h

@@ -11,6 +11,10 @@ enum {
 	IPSET_ERR_INVALID_PROTO,
 	/* Protocol missing but must be specified */
 	IPSET_ERR_MISSING_PROTO,
+	/* Range not supported */
+	IPSET_ERR_HASH_RANGE_UNSUPPORTED,
+	/* Invalid range */
+	IPSET_ERR_HASH_RANGE,
 };
 
 #ifdef __KERNEL__

include/linux/netfilter/ipset/pfxlen.h

@@ -3,6 +3,7 @@
 
 #include <asm/byteorder.h>
 #include <linux/netfilter.h> 
+#include <net/tcp.h>
 
 /* Prefixlen maps, by Jan Engelhardt  */
 extern const union nf_inet_addr ip_set_netmask_map[];
@@ -32,4 +33,6 @@ ip_set_hostmask6(u8 pfxlen)
 	return &ip_set_hostmask_map[pfxlen].ip6[0];
 }
 
+extern u32 ip_set_range_to_cidr(u32 from, u32 to, u8 *cidr);
+
 #endif /*_PFXLEN_H */