#ifndef __LINUX_NETLINK_H
  #define __LINUX_NETLINK_H
  
  #include <linux/socket.h> /* for sa_family_t */
  #include <linux/types.h>
  
  #define NETLINK_ROUTE		0	/* Routing/device hook				*/

  #define NETLINK_UNUSED		1	/* Unused number				*/

  #define NETLINK_USERSOCK	2	/* Reserved for user mode socket protocols 	*/
  #define NETLINK_FIREWALL	3	/* Firewalling hook				*/

  #define NETLINK_INET_DIAG	4	/* INET socket monitoring			*/

  #define NETLINK_NFLOG		5	/* netfilter/iptables ULOG */
  #define NETLINK_XFRM		6	/* ipsec */
  #define NETLINK_SELINUX		7	/* SELinux event notifications */

  #define NETLINK_ISCSI		8	/* Open-iSCSI */

  #define NETLINK_AUDIT		9	/* auditing */

  #define NETLINK_FIB_LOOKUP	10	

  #define NETLINK_CONNECTOR	11

  #define NETLINK_NETFILTER	12	/* netfilter subsystem */

  #define NETLINK_IP6_FW		13
  #define NETLINK_DNRTMSG		14	/* DECnet routing messages */
  #define NETLINK_KOBJECT_UEVENT	15	/* Kernel messages to userspace */

  #define NETLINK_GENERIC		16

  /* leave room for NETLINK_DM (DM Events) */
  #define NETLINK_SCSITRANSPORT	18	/* SCSI Transports */

  #define NETLINK_ECRYPTFS	19

  
  #define MAX_LINKS 32		

  struct net;

  struct sockaddr_nl {

  	sa_family_t	nl_family;	/* AF_NETLINK	*/
  	unsigned short	nl_pad;		/* zero		*/

  	__u32		nl_pid;		/* port ID	*/

         	__u32		nl_groups;	/* multicast groups mask */
  };

  struct nlmsghdr {

  	__u32		nlmsg_len;	/* Length of message including header */
  	__u16		nlmsg_type;	/* Message content */
  	__u16		nlmsg_flags;	/* Additional flags */
  	__u32		nlmsg_seq;	/* Sequence number */

  	__u32		nlmsg_pid;	/* Sending process port ID */

  };
  
  /* Flags values */
  
  #define NLM_F_REQUEST		1	/* It is request message. 	*/
  #define NLM_F_MULTI		2	/* Multipart message, terminated by NLMSG_DONE */
  #define NLM_F_ACK		4	/* Reply with ack, with zero or error code */
  #define NLM_F_ECHO		8	/* Echo this request 		*/
  
  /* Modifiers to GET request */
  #define NLM_F_ROOT	0x100	/* specify tree	root	*/
  #define NLM_F_MATCH	0x200	/* return all matching	*/
  #define NLM_F_ATOMIC	0x400	/* atomic GET		*/
  #define NLM_F_DUMP	(NLM_F_ROOT|NLM_F_MATCH)
  
  /* Modifiers to NEW request */
  #define NLM_F_REPLACE	0x100	/* Override existing		*/
  #define NLM_F_EXCL	0x200	/* Do not touch, if it exists	*/
  #define NLM_F_CREATE	0x400	/* Create, if it does not exist	*/
  #define NLM_F_APPEND	0x800	/* Add to end of list		*/
  
  /*
     4.4BSD ADD		NLM_F_CREATE|NLM_F_EXCL
     4.4BSD CHANGE	NLM_F_REPLACE
  
     True CHANGE		NLM_F_CREATE|NLM_F_REPLACE
     Append		NLM_F_CREATE
     Check		NLM_F_EXCL
   */
  
  #define NLMSG_ALIGNTO	4
  #define NLMSG_ALIGN(len) ( ((len)+NLMSG_ALIGNTO-1) & ~(NLMSG_ALIGNTO-1) )

  #define NLMSG_HDRLEN	 ((int) NLMSG_ALIGN(sizeof(struct nlmsghdr)))
  #define NLMSG_LENGTH(len) ((len)+NLMSG_ALIGN(NLMSG_HDRLEN))

  #define NLMSG_SPACE(len) NLMSG_ALIGN(NLMSG_LENGTH(len))
  #define NLMSG_DATA(nlh)  ((void*)(((char*)nlh) + NLMSG_LENGTH(0)))
  #define NLMSG_NEXT(nlh,len)	 ((len) -= NLMSG_ALIGN((nlh)->nlmsg_len), \
  				  (struct nlmsghdr*)(((char*)(nlh)) + NLMSG_ALIGN((nlh)->nlmsg_len)))
  #define NLMSG_OK(nlh,len) ((len) >= (int)sizeof(struct nlmsghdr) && \
  			   (nlh)->nlmsg_len >= sizeof(struct nlmsghdr) && \
  			   (nlh)->nlmsg_len <= (len))
  #define NLMSG_PAYLOAD(nlh,len) ((nlh)->nlmsg_len - NLMSG_SPACE((len)))
  
  #define NLMSG_NOOP		0x1	/* Nothing.		*/
  #define NLMSG_ERROR		0x2	/* Error		*/
  #define NLMSG_DONE		0x3	/* End of a dump	*/
  #define NLMSG_OVERRUN		0x4	/* Data lost		*/

  #define NLMSG_MIN_TYPE		0x10	/* < 0x10: reserved control messages */

  struct nlmsgerr {

  	int		error;
  	struct nlmsghdr msg;
  };

  #define NETLINK_ADD_MEMBERSHIP	1
  #define NETLINK_DROP_MEMBERSHIP	2
  #define NETLINK_PKTINFO		3

  #define NETLINK_BROADCAST_ERROR	4

  #define NETLINK_NO_ENOBUFS	5

  struct nl_pktinfo {

  	__u32	group;
  };

  #define NET_MAJOR 36		/* Major 36 is reserved for networking 						*/
  
  enum {
  	NETLINK_UNCONNECTED = 0,
  	NETLINK_CONNECTED,
  };

  /*
   *  <------- NLA_HDRLEN ------> <-- NLA_ALIGN(payload)-->
   * +---------------------+- - -+- - - - - - - - - -+- - -+
   * |        Header       | Pad |     Payload       | Pad |
   * |   (struct nlattr)   | ing |                   | ing |
   * +---------------------+- - -+- - - - - - - - - -+- - -+
   *  <-------------- nlattr->nla_len -------------->
   */

  struct nlattr {

  	__u16           nla_len;
  	__u16           nla_type;
  };

  /*
   * nla_type (16 bits)
   * +---+---+-------------------------------+
   * | N | O | Attribute Type                |
   * +---+---+-------------------------------+
   * N := Carries nested attributes
   * O := Payload stored in network byte order
   *
   * Note: The N and O flag are mutually exclusive.
   */
  #define NLA_F_NESTED		(1 << 15)
  #define NLA_F_NET_BYTEORDER	(1 << 14)
  #define NLA_TYPE_MASK		~(NLA_F_NESTED | NLA_F_NET_BYTEORDER)

  #define NLA_ALIGNTO		4
  #define NLA_ALIGN(len)		(((len) + NLA_ALIGNTO - 1) & ~(NLA_ALIGNTO - 1))
  #define NLA_HDRLEN		((int) NLA_ALIGN(sizeof(struct nlattr)))

  #ifdef __KERNEL__
  
  #include <linux/capability.h>
  #include <linux/skbuff.h>

  static inline struct nlmsghdr *nlmsg_hdr(const struct sk_buff *skb)
  {
  	return (struct nlmsghdr *)skb->data;
  }

  struct netlink_skb_parms {

  	struct ucred		creds;		/* Skb credentials	*/
  	__u32			pid;

  	__u32			dst_group;

  	kernel_cap_t		eff_cap;

  	__u32			loginuid;	/* Login (audit) uid */

  	__u32			sessionid;	/* Session id (audit) */

  	__u32			sid;		/* SELinux security id */

  };
  
  #define NETLINK_CB(skb)		(*(struct netlink_skb_parms*)&((skb)->cb))
  #define NETLINK_CREDS(skb)	(&NETLINK_CB((skb)).creds)

  extern void netlink_table_grab(void);
  extern void netlink_table_ungrab(void);

  extern struct sock *netlink_kernel_create(struct net *net,
  					  int unit,unsigned int groups,

  					  void (*input)(struct sk_buff *skb),

  					  struct mutex *cb_mutex,
  					  struct module *module);

  extern void netlink_kernel_release(struct sock *sk);

  extern int __netlink_change_ngroups(struct sock *sk, unsigned int groups);

  extern int netlink_change_ngroups(struct sock *sk, unsigned int groups);

  extern void __netlink_clear_multicast_users(struct sock *sk, unsigned int group);

  extern void netlink_clear_multicast_users(struct sock *sk, unsigned int group);

  extern void netlink_ack(struct sk_buff *in_skb, struct nlmsghdr *nlh, int err);

  extern int netlink_has_listeners(struct sock *sk, unsigned int group);

  extern int netlink_unicast(struct sock *ssk, struct sk_buff *skb, __u32 pid, int nonblock);
  extern int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, __u32 pid,

  			     __u32 group, gfp_t allocation);

  extern int netlink_broadcast_filtered(struct sock *ssk, struct sk_buff *skb,
  	__u32 pid, __u32 group, gfp_t allocation,
  	int (*filter)(struct sock *dsk, struct sk_buff *skb, void *data),
  	void *filter_data);

  extern int netlink_set_err(struct sock *ssk, __u32 pid, __u32 group, int code);

  extern int netlink_register_notifier(struct notifier_block *nb);
  extern int netlink_unregister_notifier(struct notifier_block *nb);
  
  /* finegrained unicast helpers: */
  struct sock *netlink_getsockbyfilp(struct file *filp);

  int netlink_attachskb(struct sock *sk, struct sk_buff *skb,

  		      long *timeo, struct sock *ssk);

  void netlink_detachskb(struct sock *sk, struct sk_buff *skb);

  int netlink_sendskb(struct sock *sk, struct sk_buff *skb);

  
  /*
   *	skb should fit one page. This choice is good for headerless malloc.

   *	But we should limit to 8K so that userspace does not have to
   *	use enormous buffer sizes on recvmsg() calls just to avoid
   *	MSG_TRUNC when PAGE_SIZE is very large.

   */

  #if PAGE_SIZE < 8192UL
  #define NLMSG_GOODSIZE	SKB_WITH_OVERHEAD(PAGE_SIZE)
  #else
  #define NLMSG_GOODSIZE	SKB_WITH_OVERHEAD(8192UL)
  #endif

  #define NLMSG_DEFAULT_SIZE (NLMSG_GOODSIZE - NLMSG_HDRLEN)

  struct netlink_callback {

  	struct sk_buff		*skb;
  	const struct nlmsghdr	*nlh;
  	int			(*dump)(struct sk_buff * skb,
  					struct netlink_callback *cb);
  	int			(*done)(struct netlink_callback *cb);
  	int			family;
  	long			args[6];

  };

  struct netlink_notify {

  	struct net *net;

  	int pid;
  	int protocol;
  };
  
  static __inline__ struct nlmsghdr *

  __nlmsg_put(struct sk_buff *skb, u32 pid, u32 seq, int type, int len, int flags)

  {
  	struct nlmsghdr *nlh;
  	int size = NLMSG_LENGTH(len);
  
  	nlh = (struct nlmsghdr*)skb_put(skb, NLMSG_ALIGN(size));
  	nlh->nlmsg_type = type;
  	nlh->nlmsg_len = size;

  	nlh->nlmsg_flags = flags;

  	nlh->nlmsg_pid = pid;
  	nlh->nlmsg_seq = seq;

  	if (!__builtin_constant_p(size) || NLMSG_ALIGN(size) - size != 0)
  		memset(NLMSG_DATA(nlh) + len, 0, NLMSG_ALIGN(size) - size);

  	return nlh;
  }

  #define NLMSG_NEW(skb, pid, seq, type, len, flags) \

  ({	if (unlikely(skb_tailroom(skb) < (int)NLMSG_SPACE(len))) \

  		goto nlmsg_failure; \

  	__nlmsg_put(skb, pid, seq, type, len, flags); })
  
  #define NLMSG_PUT(skb, pid, seq, type, len) \
  	NLMSG_NEW(skb, pid, seq, type, len, 0)

  extern int netlink_dump_start(struct sock *ssk, struct sk_buff *skb,

  			      const struct nlmsghdr *nlh,

  			      int (*dump)(struct sk_buff *skb, struct netlink_callback*),
  			      int (*done)(struct netlink_callback*));
  
  
  #define NL_NONROOT_RECV 0x1
  #define NL_NONROOT_SEND 0x2
  extern void netlink_set_nonroot(int protocol, unsigned flag);
  
  #endif /* __KERNEL__ */
  
  #endif	/* __LINUX_NETLINK_H */