netfilter: ipset: Add support for new bitmask parameter

Add a new parameter to complement the existing 'netmask' option. The
main difference between netmask and bitmask is that bitmask takes any
arbitrary ip address as input, it does not have to be a valid netmask.

The name of the new parameter is 'bitmask'. This lets us mask out
arbitrary bits in the ip address, for example:
ipset create set1 hash:ip bitmask 255.128.255.0
ipset create set2 hash:ip,port family inet6 bitmask ffff::ff80

Signed-off-by: Vishwanath Pai <vpai@akamai.com>
Signed-off-by: Joshua Hunt <johunt@akamai.com>
Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org>

1 files changed, 23 insertions, 1 deletions

diff --git a/kernel/net/netfilter/ipset/ip_set_hash_ipport.c b/kernel/net/netfilter/ipset/ip_set_hash_ipport.c
index 09837c3..5ca5df9 100644
--- a/kernel/net/netfilter/ipset/ip_set_hash_ipport.c
+++ b/kernel/net/netfilter/ipset/ip_set_hash_ipport.c
@@ -27,7 +27,8 @@
 /*				3    Comments support added */
 /*				4    Forceadd support added */
 /*				5    skbinfo support added */
-#define IPSET_TYPE_REV_MAX	6 /* bucketsize, initval support added */
+/*				6    bucketsize, initval support added */
+#define IPSET_TYPE_REV_MAX	7 /* bitmask support added */
 
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Jozsef Kadlecsik <kadlec@netfilter.org>");
@@ -36,6 +37,8 @@ MODULE_ALIAS("ip_set_hash:ip,port");
 
 /* Type specific function prefix */
 #define HTYPE		hash_ipport
+#define IP_SET_HASH_WITH_NETMASK
+#define IP_SET_HASH_WITH_BITMASK
 
 /* IPv4 variant */
 
@@ -93,12 +96,16 @@ hash_ipport4_kadt(struct ip_set *set, const struct sk_buff *skb,
 	ipset_adtfn adtfn = set->variant->adt[adt];
 	struct hash_ipport4_elem e = { .ip = 0 };
 	struct ip_set_ext ext = IP_SET_INIT_KEXT(skb, opt, set);
+	const struct MTYPE *h = set->data;
 
 	if (!ip_set_get_ip4_port(skb, opt->flags & IPSET_DIM_TWO_SRC,
 				 &e.port, &e.proto))
 		return -EINVAL;
 
 	ip4addrptr(skb, opt->flags & IPSET_DIM_ONE_SRC, &e.ip);
+	e.ip &= h->bitmask.ip;
+	if (e.ip == 0)
+		return -EINVAL;
 	return adtfn(set, &e, &ext, &opt->ext, opt->cmdflags);
 }
 
@@ -130,6 +137,10 @@ hash_ipport4_uadt(struct ip_set *set, struct nlattr *tb[],
 	if (ret)
 		return ret;
 
+	e.ip &= h->bitmask.ip;
+	if (e.ip == 0)
+		return -EINVAL;
+
 	e.port = nla_get_be16(tb[IPSET_ATTR_PORT]);
 
 	if (tb[IPSET_ATTR_PROTO]) {
@@ -254,12 +265,17 @@ hash_ipport6_kadt(struct ip_set *set, const struct sk_buff *skb,
 	ipset_adtfn adtfn = set->variant->adt[adt];
 	struct hash_ipport6_elem e = { .ip = { .all = { 0 } } };
 	struct ip_set_ext ext = IP_SET_INIT_KEXT(skb, opt, set);
+	const struct MTYPE *h = set->data;
 
 	if (!ip_set_get_ip6_port(skb, opt->flags & IPSET_DIM_TWO_SRC,
 				 &e.port, &e.proto))
 		return -EINVAL;
 
 	ip6addrptr(skb, opt->flags & IPSET_DIM_ONE_SRC, &e.ip.in6);
+	nf_inet_addr_mask_inplace(&e.ip, &h->bitmask);
+	if (ipv6_addr_any(&e.ip.in6))
+		return -EINVAL;
+
 	return adtfn(set, &e, &ext, &opt->ext, opt->cmdflags);
 }
 
@@ -299,6 +315,10 @@ hash_ipport6_uadt(struct ip_set *set, struct nlattr *tb[],
 	if (ret)
 		return ret;
 
+	nf_inet_addr_mask_inplace(&e.ip, &h->bitmask);
+	if (ipv6_addr_any(&e.ip.in6))
+		return -EINVAL;
+
 	e.port = nla_get_be16(tb[IPSET_ATTR_PORT]);
 
 	if (tb[IPSET_ATTR_PROTO]) {
@@ -357,6 +377,8 @@ static struct ip_set_type hash_ipport_type __read_mostly = {
 		[IPSET_ATTR_PROTO]	= { .type = NLA_U8 },
 		[IPSET_ATTR_TIMEOUT]	= { .type = NLA_U32 },
 		[IPSET_ATTR_CADT_FLAGS]	= { .type = NLA_U32 },
+		[IPSET_ATTR_NETMASK]	= { .type = NLA_U8 },
+		[IPSET_ATTR_BITMASK]	= { .type = NLA_NESTED },
 	},
 	.adt_policy	= {
 		[IPSET_ATTR_IP]		= { .type = NLA_NESTED },