#ifndef _NETINET_ICMP_H
#define _NETINET_ICMP_H

#include <stdint.h>

#ifdef __cplusplus
extern "C" {
#endif

#include <netinet/in.h>
#include <netinet/ip.h>

struct icmphdr {
	uint8_t type;
	uint8_t code;
	uint16_t checksum;
	union {
		struct {
			uint16_t id;
			uint16_t sequence;
		} echo;
		uint32_t gateway;
		struct {
			uint16_t __unused;
			uint16_t mtu;
		} frag;
		uint8_t reserved[4];
	} un;
};

#define ICMP_ECHOREPLY 0
#define ICMP_DEST_UNREACH 3
#define ICMP_SOURCE_QUENCH 4
#define ICMP_REDIRECT 5
#define ICMP_ECHO 8
#define ICMP_TIME_EXCEEDED 11
#define ICMP_PARAMETERPROB 12
#define ICMP_TIMESTAMP 13
#define ICMP_TIMESTAMPREPLY 14
#define ICMP_INFO_REQUEST 15
#define ICMP_INFO_REPLY 16
#define ICMP_ADDRESS 17
#define ICMP_ADDRESSREPLY 18

#define ICMP_NET_UNREACH 0
#define ICMP_HOST_UNREACH 1
#define ICMP_PROT_UNREACH 2
#define ICMP_PORT_UNREACH 3
#define ICMP_FRAG_NEEDED 4
#define ICMP_SR_FAILED 5
#define ICMP_NET_UNKNOWN 6
#define ICMP_HOST_UNKNOWN 7
#define ICMP_HOST_ISOLATED 8
#define ICMP_NET_ANO 9
#define ICMP_HOST_ANO 10
#define ICMP_NET_UNR_TOS 11
#define ICMP_HOST_UNR_TOS 12
#define ICMP_PKT_FILTERED 13
#define ICMP_PREC_VIOLATION 14
#define ICMP_PREC_CUTOFF 15
#define NR_ICMP_UNREACH 15

#define ICMP_REDIR_NET 0
#define ICMP_REDIR_HOST 1
#define ICMP_REDIR_NETTOS 2
#define ICMP_REDIR_HOSTTOS 3

#define ICMP_EXC_TTL 0
#define ICMP_EXC_FRAGTIME 1

#define ICMP_ADVLENMIN (8 + sizeof(struct ip) + 8)

struct icmp_ra_addr {
	uint32_t ira_addr;
	uint32_t ira_preference;
};

struct icmp {
	uint8_t icmp_type;
	uint8_t icmp_code;
	uint16_t icmp_cksum;
	union {
		unsigned char ih_pptr;
		struct in_addr ih_gwaddr;
		struct ih_idseq {
			uint16_t icd_id;
			uint16_t icd_seq;
		} ih_idseq;
		uint32_t ih_void;
		
		struct ih_pmtu {
			uint16_t ipm_void;
			uint16_t ipm_nextmtu;
		} ih_pmtu;
		
		struct ih_rtradv {
			uint8_t irt_num_addrs;
			uint8_t irt_wpa;
			uint16_t irt_lifetime;
		} ih_rtradv;
	} icmp_hun;
	union {
		struct {
			uint32_t its_otime;
			uint32_t its_rtime;
			uint32_t its_ttime;
		} id_ts;
		struct {
			struct ip idi_ip;
		} id_ip;
		struct icmp_ra_addr id_radv;
		uint32_t id_mask;
		uint8_t id_data[1];
	} icmp_dun;
};

#define	icmp_pptr icmp_hun.ih_pptr
#define	icmp_gwaddr	icmp_hun.ih_gwaddr
#define	icmp_id	icmp_hun.ih_idseq.icd_id
#define	icmp_seq icmp_hun.ih_idseq.icd_seq
#define	icmp_void icmp_hun.ih_void
#define	icmp_pmvoid	icmp_hun.ih_pmtu.ipm_void
#define	icmp_nextmtu icmp_hun.ih_pmtu.ipm_nextmtu
#define	icmp_num_addrs icmp_hun.ih_rtradv.irt_num_addrs
#define	icmp_wpa icmp_hun.ih_rtradv.irt_wpa
#define	icmp_lifetime icmp_hun.ih_rtradv.irt_lifetime

#define	icmp_otime icmp_dun.id_ts.its_otime
#define	icmp_rtime icmp_dun.id_ts.its_rtime
#define	icmp_ttime icmp_dun.id_ts.its_ttime
#define	icmp_ip	icmp_dun.id_ip.idi_ip
#define	icmp_radv icmp_dun.id_radv
#define	icmp_mask icmp_dun.id_mask
#define	icmp_data icmp_dun.id_data

#ifdef __cplusplus
}
#endif

#endif /* _NETINET_ICMP_H */