netfilter: ipset: list:set set type support

The module implements the list:set type support in two flavours:
without and with timeout. The sets has two sides: for the userspace,
they store the names of other (non list:set type of) sets: one can add,
delete and test set names. For the kernel, it forms an ordered union of
the member sets: the members sets are tried in order when elements are
added, deleted and tested and the process stops at the first success.

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

include/linux/netfilter/ipset/ip_set_list.h

@@ -0,0 +1,27 @@
+#ifndef __IP_SET_LIST_H
+#define __IP_SET_LIST_H
+
+/* List type specific error codes */
+enum {
+	/* Set name to be added/deleted/tested does not exist. */
+	IPSET_ERR_NAME = IPSET_ERR_TYPE_SPECIFIC,
+	/* list:set type is not permitted to add */
+	IPSET_ERR_LOOP,
+	/* Missing reference set */
+	IPSET_ERR_BEFORE,
+	/* Reference set does not exist */
+	IPSET_ERR_NAMEREF,
+	/* Set is full */
+	IPSET_ERR_LIST_FULL,
+	/* Reference set is not added to the set */
+	IPSET_ERR_REF_EXIST,
+};
+
+#ifdef __KERNEL__
+
+#define IP_SET_LIST_DEFAULT_SIZE	8
+#define IP_SET_LIST_MIN_SIZE		4
+
+#endif /* __KERNEL__ */
+
+#endif /* __IP_SET_LIST_H */

net/netfilter/ipset/Kconfig

@@ -108,4 +108,14 @@ config IP_SET_HASH_NETPORT
 
 	  To compile it as a module, choose M here.  If unsure, say N.
 
+config IP_SET_LIST_SET
+	tristate "list:set set support"
+	depends on IP_SET
+	help
+	  This option adds the list:set set type support. In this
+	  kind of set one can store the name of other sets and it forms
+	  an ordered union of the member sets.
+
+	  To compile it as a module, choose M here.  If unsure, say N.
+
 endif # IP_SET

net/netfilter/ipset/Makefile

@@ -19,3 +19,6 @@ obj-$(CONFIG_IP_SET_HASH_IPPORTIP) += ip_set_hash_ipportip.o
 obj-$(CONFIG_IP_SET_HASH_IPPORTNET) += ip_set_hash_ipportnet.o
 obj-$(CONFIG_IP_SET_HASH_NET) += ip_set_hash_net.o
 obj-$(CONFIG_IP_SET_HASH_NETPORT) += ip_set_hash_netport.o
+
+# list types
+obj-$(CONFIG_IP_SET_LIST_SET) += ip_set_list_set.o