// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * libnetlink.c	RTnetlink service routines.
 *
 * Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
 *
 */

#ifdef __linux__

#ifndef __LIBNETLINK_H__
#define __LIBNETLINK_H__ 1

#include <asm/types.h>
#include <linux/netlink.h>
#include <linux/rtnetlink.h>
#include <linux/if_link.h>
#include <linux/if_addr.h>
#include <linux/neighbour.h>

struct rtnl_handle {
	int fd;
	struct sockaddr_nl local;
	struct sockaddr_nl peer;
	__u32 seq;
	__u32 dump;
};

extern int rcvbuf;

extern int rtnl_open(struct rtnl_handle *rth, unsigned subscriptions);
extern int rtnl_open_byproto(struct rtnl_handle *rth, unsigned subscriptions,
			     int protocol);
extern void rtnl_close(struct rtnl_handle *rth);
extern int rtnl_wilddump_request(struct rtnl_handle *rth, int fam, int type);
extern int rtnl_dump_request(struct rtnl_handle *rth, int type, void *req,
			     int len);

typedef int (*rtnl_filter_t)(const struct sockaddr_nl *, struct nlmsghdr *n,
			     void *);

struct rtnl_dump_filter_arg {
	rtnl_filter_t filter;
	void *arg1;
	rtnl_filter_t junk;
	void *arg2;
};

extern int rtnl_dump_filter_l(struct rtnl_handle *rth,
			      const struct rtnl_dump_filter_arg *arg);
extern int rtnl_dump_filter(struct rtnl_handle *rth, rtnl_filter_t filter,
			    void *arg1, rtnl_filter_t junk, void *arg2);

extern int rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n, pid_t peer,
		     unsigned groups, struct nlmsghdr *answer,
		     rtnl_filter_t junk, void *jarg);
extern int rtnl_send(struct rtnl_handle *rth, const char *buf, int);
extern int rtnl_send_check(struct rtnl_handle *rth, const char *buf, int);

extern int addattr32(struct nlmsghdr *n, int maxlen, int type, __u32 data);
extern int addattr_l(struct nlmsghdr *n, int maxlen, int type, const void *data,
		     int alen);
extern int addraw_l(struct nlmsghdr *n, int maxlen, const void *data, int len);
extern struct rtattr *addattr_nest(struct nlmsghdr *n, int maxlen, int type);
extern int addattr_nest_end(struct nlmsghdr *n, struct rtattr *nest);
extern struct rtattr *addattr_nest_compat(struct nlmsghdr *n, int maxlen,
					  int type, const void *data, int len);
extern int addattr_nest_compat_end(struct nlmsghdr *n, struct rtattr *nest);
extern int rta_addattr32(struct rtattr *rta, int maxlen, int type, __u32 data);
extern int rta_addattr_l(struct rtattr *rta, int maxlen, int type,
			 const void *data, int alen);

extern int parse_rtattr(struct rtattr *tb[], int max, struct rtattr *rta,
			int len);
extern int parse_rtattr_byindex(struct rtattr *tb[], int max,
				struct rtattr *rta, int len);
extern int __parse_rtattr_nested_compat(struct rtattr *tb[], int max,
					struct rtattr *rta, int len);

#define parse_rtattr_nested(tb, max, rta)                                      \
	(parse_rtattr((tb), (max), RTA_DATA(rta), RTA_PAYLOAD(rta)))

#define parse_rtattr_nested_compat(tb, max, rta, data, len)                    \
	({                                                                     \
		data = RTA_PAYLOAD(rta) >= len ? RTA_DATA(rta) : NULL;         \
		__parse_rtattr_nested_compat(tb, max, rta, len);               \
	})

extern int rtnl_listen(struct rtnl_handle *, rtnl_filter_t handler, void *jarg);
extern int rtnl_from_file(FILE *, rtnl_filter_t handler, void *jarg);

#define NLMSG_TAIL(nmsg)                                                       \
	((struct rtattr *)(((uint8_t *)(nmsg))                                 \
			   + NLMSG_ALIGN((nmsg)->nlmsg_len)))

#ifndef IFA_RTA
#define IFA_RTA(r)                                                             \
	((struct rtattr *)(((char *)(r))                                       \
			   + NLMSG_ALIGN(sizeof(struct ifaddrmsg))))
#endif
#ifndef IFA_PAYLOAD
#define IFA_PAYLOAD(n)	NLMSG_PAYLOAD(n,sizeof(struct ifaddrmsg))
#endif

#ifndef IFLA_RTA
#define IFLA_RTA(r)                                                            \
	((struct rtattr *)(((char *)(r))                                       \
			   + NLMSG_ALIGN(sizeof(struct ifinfomsg))))
#endif
#ifndef IFLA_PAYLOAD
#define IFLA_PAYLOAD(n)	NLMSG_PAYLOAD(n,sizeof(struct ifinfomsg))
#endif

#ifndef NDA_RTA
#define NDA_RTA(r)                                                             \
	((struct rtattr *)(((char *)(r)) + NLMSG_ALIGN(sizeof(struct ndmsg))))
#endif
#ifndef NDA_PAYLOAD
#define NDA_PAYLOAD(n)	NLMSG_PAYLOAD(n,sizeof(struct ndmsg))
#endif

#ifndef NDTA_RTA
#define NDTA_RTA(r)                                                            \
	((struct rtattr *)(((char *)(r)) + NLMSG_ALIGN(sizeof(struct ndtmsg))))
#endif
#ifndef NDTA_PAYLOAD
#define NDTA_PAYLOAD(n) NLMSG_PAYLOAD(n,sizeof(struct ndtmsg))
#endif

#endif /* __LIBNETLINK_H__ */

#endif /* __linux__ */
