text: #ifndef _IP_SET_H
  #define _IP_SET_H
  
  /* Copyright (C) 2000-2002 Joakim Axelsson <gozem@linux.nu>
   *                         Patrick Schaaf <bof@bof.de>
   *                         Martin Josefsson <gandalf@wlug.westbo.se>
   * Copyright (C) 2003-2011 Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation.
   */
  
  /* The protocol version */
  #define IPSET_PROTOCOL		6
  
  /* The max length of strings including NUL: set and type identifiers */
  #define IPSET_MAXNAMELEN	32
  
  /* Message types and commands */
  enum ipset_cmd {
  	IPSET_CMD_NONE,
  	IPSET_CMD_PROTOCOL,	/* 1: Return protocol version */
  	IPSET_CMD_CREATE,	/* 2: Create a new (empty) set */
  	IPSET_CMD_DESTROY,	/* 3: Destroy a (empty) set */
  	IPSET_CMD_FLUSH,	/* 4: Remove all elements from a set */
  	IPSET_CMD_RENAME,	/* 5: Rename a set */
  	IPSET_CMD_SWAP,		/* 6: Swap two sets */
  	IPSET_CMD_LIST,		/* 7: List sets */
  	IPSET_CMD_SAVE,		/* 8: Save sets */
  	IPSET_CMD_ADD,		/* 9: Add an element to a set */
  	IPSET_CMD_DEL,		/* 10: Delete an element from a set */
  	IPSET_CMD_TEST,		/* 11: Test an element in a set */
  	IPSET_CMD_HEADER,	/* 12: Get set header data only */
  	IPSET_CMD_TYPE,		/* 13: Get set type */
  	IPSET_MSG_MAX,		/* Netlink message commands */
  
  	/* Commands in userspace: */
  	IPSET_CMD_RESTORE = IPSET_MSG_MAX, /* 14: Enter restore mode */
  	IPSET_CMD_HELP,		/* 15: Get help */
  	IPSET_CMD_VERSION,	/* 16: Get program version */
  	IPSET_CMD_QUIT,		/* 17: Quit from interactive mode */
  
  	IPSET_CMD_MAX,
  
  	IPSET_CMD_COMMIT = IPSET_CMD_MAX, /* 18: Commit buffered commands */
  };
  
  /* Attributes at command level */
  enum {
  	IPSET_ATTR_UNSPEC,
  	IPSET_ATTR_PROTOCOL,	/* 1: Protocol version */
  	IPSET_ATTR_SETNAME,	/* 2: Name of the set */
  	IPSET_ATTR_TYPENAME,	/* 3: Typename */
  	IPSET_ATTR_SETNAME2 = IPSET_ATTR_TYPENAME, /* Setname at rename/swap */
  	IPSET_ATTR_REVISION,	/* 4: Settype revision */
  	IPSET_ATTR_FAMILY,	/* 5: Settype family */
  	IPSET_ATTR_FLAGS,	/* 6: Flags at command level */
  	IPSET_ATTR_DATA,	/* 7: Nested attributes */
  	IPSET_ATTR_ADT,		/* 8: Multiple data containers */
  	IPSET_ATTR_LINENO,	/* 9: Restore lineno */
  	IPSET_ATTR_PROTOCOL_MIN, /* 10: Minimal supported version number */
  	IPSET_ATTR_REVISION_MIN	= IPSET_ATTR_PROTOCOL_MIN, /* type rev min */
  	__IPSET_ATTR_CMD_MAX,
  };
  #define IPSET_ATTR_CMD_MAX	(__IPSET_ATTR_CMD_MAX - 1)
  
  /* CADT specific attributes */
  enum {
  	IPSET_ATTR_IP = IPSET_ATTR_UNSPEC + 1,
  	IPSET_ATTR_IP_FROM = IPSET_ATTR_IP,
  	IPSET_ATTR_IP_TO,	/* 2 */
  	IPSET_ATTR_CIDR,	/* 3 */
  	IPSET_ATTR_PORT,	/* 4 */
  	IPSET_ATTR_PORT_FROM = IPSET_ATTR_PORT,
  	IPSET_ATTR_PORT_TO,	/* 5 */
  	IPSET_ATTR_TIMEOUT,	/* 6 */
  	IPSET_ATTR_PROTO,	/* 7 */
  	IPSET_ATTR_CADT_FLAGS,	/* 8 */
  	IPSET_ATTR_CADT_LINENO = IPSET_ATTR_LINENO,	/* 9 */
  	/* Reserve empty slots */
  	IPSET_ATTR_CADT_MAX = 16,
  	/* Create-only specific attributes */
  	IPSET_ATTR_GC,
  	IPSET_ATTR_HASHSIZE,
  	IPSET_ATTR_MAXELEM,
  	IPSET_ATTR_NETMASK,
  	IPSET_ATTR_PROBES,
  	IPSET_ATTR_RESIZE,
  	IPSET_ATTR_SIZE,
  	/* Kernel-only */
  	IPSET_ATTR_ELEMENTS,
  	IPSET_ATTR_REFERENCES,
  	IPSET_ATTR_MEMSIZE,
  
  	__IPSET_ATTR_CREATE_MAX,
  };
  #define IPSET_ATTR_CREATE_MAX	(__IPSET_ATTR_CREATE_MAX - 1)
  
  /* ADT specific attributes */
  enum {
  	IPSET_ATTR_ETHER = IPSET_ATTR_CADT_MAX + 1,
  	IPSET_ATTR_NAME,
  	IPSET_ATTR_NAMEREF,
  	IPSET_ATTR_IP2,
  	IPSET_ATTR_CIDR2,
  	IPSET_ATTR_IP2_TO,
  	IPSET_ATTR_IFACE,
  	__IPSET_ATTR_ADT_MAX,
  };
  #define IPSET_ATTR_ADT_MAX	(__IPSET_ATTR_ADT_MAX - 1)
  
  /* IP specific attributes */
  enum {
  	IPSET_ATTR_IPADDR_IPV4 = IPSET_ATTR_UNSPEC + 1,
  	IPSET_ATTR_IPADDR_IPV6,
  	__IPSET_ATTR_IPADDR_MAX,
  };
  #define IPSET_ATTR_IPADDR_MAX	(__IPSET_ATTR_IPADDR_MAX - 1)
  
  /* Error codes */
  enum ipset_errno {
  	IPSET_ERR_PRIVATE = 4096,
  	IPSET_ERR_PROTOCOL,
  	IPSET_ERR_FIND_TYPE,
  	IPSET_ERR_MAX_SETS,
  	IPSET_ERR_BUSY,
  	IPSET_ERR_EXIST_SETNAME2,
  	IPSET_ERR_TYPE_MISMATCH,
  	IPSET_ERR_EXIST,
  	IPSET_ERR_INVALID_CIDR,
  	IPSET_ERR_INVALID_NETMASK,
  	IPSET_ERR_INVALID_FAMILY,
  	IPSET_ERR_TIMEOUT,
  	IPSET_ERR_REFERENCED,
  	IPSET_ERR_IPADDR_IPV4,
  	IPSET_ERR_IPADDR_IPV6,
  
  	/* Type specific error codes */
  	IPSET_ERR_TYPE_SPECIFIC = 4352,
  };
  
  /* Flags at command level */
  enum ipset_cmd_flags {
  	IPSET_FLAG_BIT_EXIST	= 0,
  	IPSET_FLAG_EXIST	= (1 << IPSET_FLAG_BIT_EXIST),
  	IPSET_FLAG_BIT_LIST_SETNAME = 1,
  	IPSET_FLAG_LIST_SETNAME	= (1 << IPSET_FLAG_BIT_LIST_SETNAME),
  	IPSET_FLAG_BIT_LIST_HEADER = 2,
  	IPSET_FLAG_LIST_HEADER	= (1 << IPSET_FLAG_BIT_LIST_HEADER),
  };
  
  /* Flags at CADT attribute level */
  enum ipset_cadt_flags {
  	IPSET_FLAG_BIT_BEFORE	= 0,
  	IPSET_FLAG_BEFORE	= (1 << IPSET_FLAG_BIT_BEFORE),
  	IPSET_FLAG_BIT_PHYSDEV	= 1,
  	IPSET_FLAG_PHYSDEV	= (1 << IPSET_FLAG_BIT_PHYSDEV),
  };
  
  /* Commands with settype-specific attributes */
  enum ipset_adt {
  	IPSET_ADD,
  	IPSET_DEL,
  	IPSET_TEST,
  	IPSET_ADT_MAX,
  	IPSET_CREATE = IPSET_ADT_MAX,
  	IPSET_CADT_MAX,
  };
  
  #ifdef __KERNEL__
  #include <linux/ip.h>
  #include <linux/ipv6.h>
  #include <linux/netlink.h>
  #include <linux/netfilter.h>
  #include <linux/netfilter/x_tables.h>
  #include <linux/vmalloc.h>
  #include <net/netlink.h>
  
  /* Sets are identified by an index in kernel space. Tweak with ip_set_id_t
   * and IPSET_INVALID_ID if you want to increase the max number of sets.
   */
  typedef u16 ip_set_id_t;
  
  #define IPSET_INVALID_ID		65535
  
  enum ip_set_dim {
  	IPSET_DIM_ZERO = 0,
  	IPSET_DIM_ONE,
  	IPSET_DIM_TWO,
  	IPSET_DIM_THREE,
  	/* Max dimension in elements.
  	 * If changed, new revision of iptables match/target is required.
  	 */
  	IPSET_DIM_MAX = 6,
  };
  
  /* Option flags for kernel operations */
  enum ip_set_kopt {
  	IPSET_INV_MATCH = (1 << IPSET_DIM_ZERO),
  	IPSET_DIM_ONE_SRC = (1 << IPSET_DIM_ONE),
  	IPSET_DIM_TWO_SRC = (1 << IPSET_DIM_TWO),
  	IPSET_DIM_THREE_SRC = (1 << IPSET_DIM_THREE),
  };
  
  /* Set features */
  enum ip_set_feature {
  	IPSET_TYPE_IP_FLAG = 0,
  	IPSET_TYPE_IP = (1 << IPSET_TYPE_IP_FLAG),
  	IPSET_TYPE_PORT_FLAG = 1,
  	IPSET_TYPE_PORT = (1 << IPSET_TYPE_PORT_FLAG),
  	IPSET_TYPE_MAC_FLAG = 2,
  	IPSET_TYPE_MAC = (1 << IPSET_TYPE_MAC_FLAG),
  	IPSET_TYPE_IP2_FLAG = 3,
  	IPSET_TYPE_IP2 = (1 << IPSET_TYPE_IP2_FLAG),
  	IPSET_TYPE_NAME_FLAG = 4,
  	IPSET_TYPE_NAME = (1 << IPSET_TYPE_NAME_FLAG),
  	IPSET_TYPE_IFACE_FLAG = 5,
  	IPSET_TYPE_IFACE = (1 << IPSET_TYPE_IFACE_FLAG),
  	/* Strictly speaking not a feature, but a flag for dumping:
  	 * this settype must be dumped last */
  	IPSET_DUMP_LAST_FLAG = 7,
  	IPSET_DUMP_LAST = (1 << IPSET_DUMP_LAST_FLAG),
  };
  
  struct ip_set;
  
  typedef int (*ipset_adtfn)(struct ip_set *set, void *value,
  			   u32 timeout, u32 flags);
  
  /* Kernel API function options */
  struct ip_set_adt_opt {
  	u8 family;		/* Actual protocol family */
  	u8 dim;			/* Dimension of match/target */
  	u8 flags;		/* Direction and negation flags */
  	u32 cmdflags;		/* Command-like flags */
  	u32 timeout;		/* Timeout value */
  };
  
  /* Set type, variant-specific part */
  struct ip_set_type_variant {
  	/* Kernelspace: test/add/del entries
  	 *		returns negative error code,
  	 *			zero for no match/success to add/delete
  	 *			positive for matching element */
  	int (*kadt)(struct ip_set *set, const struct sk_buff * skb,
  		    const struct xt_action_param *par,
  		    enum ipset_adt adt, const struct ip_set_adt_opt *opt);
  
  	/* Userspace: test/add/del entries
  	 *		returns negative error code,
  	 *			zero for no match/success to add/delete
  	 *			positive for matching element */
  	int (*uadt)(struct ip_set *set, struct nlattr *tb[],
  		    enum ipset_adt adt, u32 *lineno, u32 flags, bool retried);
  
  	/* Low level add/del/test functions */
  	ipset_adtfn adt[IPSET_ADT_MAX];
  
  	/* When adding entries and set is full, try to resize the set */
  	int (*resize)(struct ip_set *set, bool retried);
  	/* Destroy the set */
  	void (*destroy)(struct ip_set *set);
  	/* Flush the elements */
  	void (*flush)(struct ip_set *set);
  	/* Expire entries before listing */
  	void (*expire)(struct ip_set *set);
  	/* List set header data */
  	int (*head)(struct ip_set *set, struct sk_buff *skb);
  	/* List elements */
  	int (*list)(const struct ip_set *set, struct sk_buff *skb,
  		    struct netlink_callback *cb);
  
  	/* Return true if "b" set is the same as "a"
  	 * according to the create set parameters */
  	bool (*same_set)(const struct ip_set *a, const struct ip_set *b);
  };
  
  /* The core set type structure */
  struct ip_set_type {
  	struct list_head list;
  
  	/* Typename */
  	char name[IPSET_MAXNAMELEN];
  	/* Protocol version */
  	u8 protocol;
  	/* Set features to control swapping */
  	u8 features;
  	/* Set type dimension */
  	u8 dimension;
  	/* Supported family: may be AF_UNSPEC for both AF_INET/AF_INET6 */
  	u8 family;
  	/* Type revisions */
  	u8 revision_min, revision_max;
  
  	/* Create set */
  	int (*create)(struct ip_set *set, struct nlattr *tb[], u32 flags);
  
  	/* Attribute policies */
  	const struct nla_policy create_policy[IPSET_ATTR_CREATE_MAX + 1];
  	const struct nla_policy adt_policy[IPSET_ATTR_ADT_MAX + 1];
  
  	/* Set this to THIS_MODULE if you are a module, otherwise NULL */
  	struct module *me;
  };
  
  /* register and unregister set type */
  extern int ip_set_type_register(struct ip_set_type *set_type);
  extern void ip_set_type_unregister(struct ip_set_type *set_type);
  
  /* A generic IP set */
  struct ip_set {
  	/* The name of the set */
  	char name[IPSET_MAXNAMELEN];
  	/* Lock protecting the set data */
  	rwlock_t lock;
  	/* References to the set */
  	u32 ref;
  	/* The core set type */
  	struct ip_set_type *type;
  	/* The type variant doing the real job */
  	const struct ip_set_type_variant *variant;
  	/* The actual INET family of the set */
  	u8 family;
  	/* The type revision */
  	u8 revision;
  	/* The type specific data */
  	void *data;
  };
  
  /* register and unregister set references */
  extern ip_set_id_t ip_set_get_byname(const char *name, struct ip_set **set);
  extern void ip_set_put_byindex(ip_set_id_t index);
  extern const char *ip_set_name_byindex(ip_set_id_t index);
  extern ip_set_id_t ip_set_nfnl_get(const char *name);
  extern ip_set_id_t ip_set_nfnl_get_byindex(ip_set_id_t index);
  extern void ip_set_nfnl_put(ip_set_id_t index);
  
  /* API for iptables set match, and SET target */
  
  extern int ip_set_add(ip_set_id_t id, const struct sk_buff *skb,
  		      const struct xt_action_param *par,
  		      const struct ip_set_adt_opt *opt);
  extern int ip_set_del(ip_set_id_t id, const struct sk_buff *skb,
  		      const struct xt_action_param *par,
  		      const struct ip_set_adt_opt *opt);
  extern int ip_set_test(ip_set_id_t id, const struct sk_buff *skb,
  		       const struct xt_action_param *par,
  		       const struct ip_set_adt_opt *opt);
  
  /* Utility functions */
  extern void *ip_set_alloc(size_t size);
  extern void ip_set_free(void *members);
  extern int ip_set_get_ipaddr4(struct nlattr *nla,  __be32 *ipaddr);
  extern int ip_set_get_ipaddr6(struct nlattr *nla, union nf_inet_addr *ipaddr);
  
  static inline int
  ip_set_get_hostipaddr4(struct nlattr *nla, u32 *ipaddr)
  {
  	__be32 ip;
  	int ret = ip_set_get_ipaddr4(nla, &ip);
  
  	if (ret)
  		return ret;
  	*ipaddr = ntohl(ip);
  	return 0;
  }
  
  /* Ignore IPSET_ERR_EXIST errors if asked to do so? */
  static inline bool
  ip_set_eexist(int ret, u32 flags)
  {
  	return ret == -IPSET_ERR_EXIST && (flags & IPSET_FLAG_EXIST);
  }
  
  /* Check the NLA_F_NET_BYTEORDER flag */
  static inline bool
  ip_set_attr_netorder(struct nlattr *tb[], int type)
  {
  	return tb[type] && (tb[type]->nla_type & NLA_F_NET_BYTEORDER);
  }
  
  static inline bool
  ip_set_optattr_netorder(struct nlattr *tb[], int type)
  {
  	return !tb[type] || (tb[type]->nla_type & NLA_F_NET_BYTEORDER);
  }
  
  /* Useful converters */
  static inline u32
  ip_set_get_h32(const struct nlattr *attr)
  {
  	return ntohl(nla_get_be32(attr));
  }
  
  static inline u16
  ip_set_get_h16(const struct nlattr *attr)
  {
  	return ntohs(nla_get_be16(attr));
  }
  
  #define ipset_nest_start(skb, attr) nla_nest_start(skb, attr | NLA_F_NESTED)
  #define ipset_nest_end(skb, start)  nla_nest_end(skb, start)
  
  #define NLA_PUT_IPADDR4(skb, type, ipaddr)			\
  do {								\
  	struct nlattr *__nested = ipset_nest_start(skb, type);	\
  								\
  	if (!__nested)						\
  		goto nla_put_failure;				\
  	NLA_PUT_NET32(skb, IPSET_ATTR_IPADDR_IPV4, ipaddr);	\
  	ipset_nest_end(skb, __nested);				\
  } while (0)
  
  #define NLA_PUT_IPADDR6(skb, type, ipaddrptr)			\
  do {								\
  	struct nlattr *__nested = ipset_nest_start(skb, type);	\
  								\
  	if (!__nested)						\
  		goto nla_put_failure;				\
  	NLA_PUT(skb, IPSET_ATTR_IPADDR_IPV6,			\
  		sizeof(struct in6_addr), ipaddrptr);		\
  	ipset_nest_end(skb, __nested);				\
  } while (0)
  
  /* Get address from skbuff */
  static inline __be32
  ip4addr(const struct sk_buff *skb, bool src)
  {
  	return src ? ip_hdr(skb)->saddr : ip_hdr(skb)->daddr;
  }
  
  static inline void
  ip4addrptr(const struct sk_buff *skb, bool src, __be32 *addr)
  {
  	*addr = src ? ip_hdr(skb)->saddr : ip_hdr(skb)->daddr;
  }
  
  static inline void
  ip6addrptr(const struct sk_buff *skb, bool src, struct in6_addr *addr)
  {
  	memcpy(addr, src ? &ipv6_hdr(skb)->saddr : &ipv6_hdr(skb)->daddr,
  	       sizeof(*addr));
  }
  
  /* Calculate the bytes required to store the inclusive range of a-b */
  static inline int
  bitmap_bytes(u32 a, u32 b)
  {
  	return 4 * ((((b - a + 8) / 8) + 3) / 4);
  }
  
  /* Interface to iptables/ip6tables */
  
  #define SO_IP_SET		83
  
  union ip_set_name_index {
  	char name[IPSET_MAXNAMELEN];
  	ip_set_id_t index;
  };
  
  #define IP_SET_OP_GET_BYNAME	0x00000006	/* Get set index by name */
  struct ip_set_req_get_set {
  	unsigned op;
  	unsigned version;
  	union ip_set_name_index set;
  };
  
  #define IP_SET_OP_GET_BYINDEX	0x00000007	/* Get set name by index */
  /* Uses ip_set_req_get_set */
  
  #define IP_SET_OP_VERSION	0x00000100	/* Ask kernel version */
  struct ip_set_req_version {
  	unsigned op;
  	unsigned version;
  };
  
  #endif	/* __KERNEL__ */
  
  #endif /*_IP_SET_H */
  