netlink.h

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#ifndef __LINUX_NETLINK_H
#define __LINUX_NETLINK_H

#include <stdint.h>
#include <sys/socket.h> /* for sa_family_t */

#define NETLINK_ROUTE		0	/* Routing/device hook				*/
#define NETLINK_SKIP		1	/* Reserved for ENskip  			*/
#define NETLINK_USERSOCK	2	/* Reserved for user mode socket protocols 	*/
#define NETLINK_FIREWALL	3	/* Firewalling hook				*/
#define NETLINK_TCPDIAG		4	/* TCP socket monitoring			*/
#define NETLINK_NFLOG		5	/* netfilter/iptables ULOG */
#define NETLINK_XFRM		6	/* ipsec */
#define NETLINK_ARPD		8
#define NETLINK_ROUTE6		11	/* af_inet6 route comm channel */
#define NETLINK_IP6_FW		13
#define NETLINK_DNRTMSG		14	/* DECnet routing messages */
#define NETLINK_TAPBASE		16	/* 16 to 31 are ethertap */

#define MAX_LINKS 32		

struct sockaddr_nl
{
	sa_family_t	nl_family;	/* AF_NETLINK	*/
	unsigned short	nl_pad;		/* zero		*/
	uint32_t	nl_pid;		/* process pid	*/
       	uint32_t	nl_groups;	/* multicast groups mask */
};

struct nlmsghdr
{
	uint32_t	nlmsg_len;	/* Length of message including header */
	uint16_t	nlmsg_type;	/* Message content */
	uint16_t	nlmsg_flags;	/* Additional flags */
	uint32_t	nlmsg_seq;	/* Sequence number */
	uint32_t	nlmsg_pid;	/* Sending process PID */
};

/* 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_LENGTH(len) ((len)+NLMSG_ALIGN(sizeof(struct nlmsghdr)))
#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) > 0 && (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		*/

struct nlmsgerr
{
	int		error;
	struct nlmsghdr msg;
};

#define NET_MAJOR 36		/* Major 36 is reserved for networking 						*/
#endif	/* __LINUX_NETLINK_H */