#ifndef NETINET_IP_ICMP_H
#define NETINET_IP_ICMP_H

#include <sys/cdefs.h>
#include <inttypes.h>

struct icmphdr {
  uint8_t type;		/* message type */
  uint8_t code;		/* type sub-code */
  uint16_t checksum;
  union {
    struct {
      uint16_t	id;
      uint16_t	sequence;
    } echo;			/* echo datagram */
    uint32_t	gateway;	/* gateway address */
    struct {
      uint16_t	__unused;
      uint16_t	mtu;
    } frag;			/* path mtu discovery */
  } un;
};

#define ICMP_ECHOREPLY		0	/* Echo Reply			*/
#define ICMP_DEST_UNREACH	3	/* Destination Unreachable	*/
#define ICMP_SOURCE_QUENCH	4	/* Source Quench		*/
#define ICMP_REDIRECT		5	/* Redirect (change route)	*/
#define ICMP_ECHO		8	/* Echo Request			*/
#define ICMP_TIME_EXCEEDED	11	/* Time Exceeded		*/
#define ICMP_PARAMETERPROB	12	/* Parameter Problem		*/
#define ICMP_TIMESTAMP		13	/* Timestamp Request		*/
#define ICMP_TIMESTAMPREPLY	14	/* Timestamp Reply		*/
#define ICMP_INFO_REQUEST	15	/* Information Request		*/
#define ICMP_INFO_REPLY		16	/* Information Reply		*/
#define ICMP_ADDRESS		17	/* Address Mask Request		*/
#define ICMP_ADDRESSREPLY	18	/* Address Mask Reply		*/
#define NR_ICMP_TYPES		18


/* Codes for UNREACH. */
#define ICMP_NET_UNREACH	0	/* Network Unreachable		*/
#define ICMP_HOST_UNREACH	1	/* Host Unreachable		*/
#define ICMP_PROT_UNREACH	2	/* Protocol Unreachable		*/
#define ICMP_PORT_UNREACH	3	/* Port Unreachable		*/
#define ICMP_FRAG_NEEDED	4	/* Fragmentation Needed/DF set	*/
#define ICMP_SR_FAILED		5	/* Source Route failed		*/
#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	/* Packet filtered */
#define ICMP_PREC_VIOLATION	14	/* Precedence violation */
#define ICMP_PREC_CUTOFF	15	/* Precedence cut off */
#define NR_ICMP_UNREACH		15	/* instead of hardcoding immediate value */

/* Codes for REDIRECT. */
#define ICMP_REDIR_NET		0	/* Redirect Net			*/
#define ICMP_REDIR_HOST		1	/* Redirect Host		*/
#define ICMP_REDIR_NETTOS	2	/* Redirect Net for TOS		*/
#define ICMP_REDIR_HOSTTOS	3	/* Redirect Host for TOS	*/

/* Codes for TIME_EXCEEDED. */
#define ICMP_EXC_TTL		0	/* TTL count exceeded		*/
#define ICMP_EXC_FRAGTIME	1	/* Fragment Reass time exceeded	*/

/*
 * Lower bounds on packet lengths for various types.
 * For the error advice packets must first insure that the
 * packet is large enough to contain the returned ip header.
 * Only then can we do the check to see if 64 bits of packet
 * data have been returned, since we need to check the returned
 * ip header length.
 */
#define	ICMP_MINLEN	8				/* abs minimum */
#define	ICMP_TSLEN	(8 + 3 * sizeof (n_time))	/* timestamp */
#define	ICMP_MASKLEN	12				/* address mask */
#define	ICMP_ADVLENMIN	(8 + sizeof (struct ip) + 8)	/* min */
#ifndef _IP_VHL
#define	ICMP_ADVLEN(p)	(8 + ((p)->icmp_ip.ip_hl << 2) + 8)
	/* N.B.: must separately check that ip_hl >= 5 */
#else
#define	ICMP_ADVLEN(p)	(8 + (IP_VHL_HL((p)->icmp_ip.ip_vhl) << 2) + 8)
	/* N.B.: must separately check that header length >= 5 */
#endif

/* Definition of type and code fields. */
/* defined above: ICMP_ECHOREPLY, ICMP_REDIRECT, ICMP_ECHO */
#define	ICMP_UNREACH		3		/* dest unreachable, codes: */
#define	ICMP_SOURCEQUENCH	4		/* packet lost, slow down */
#define	ICMP_ROUTERADVERT	9		/* router advertisement */
#define	ICMP_ROUTERSOLICIT	10		/* router solicitation */
#define	ICMP_TIMXCEED		11		/* time exceeded, code: */
#define	ICMP_PARAMPROB		12		/* ip header bad */
#define	ICMP_TSTAMP		13		/* timestamp request */
#define	ICMP_TSTAMPREPLY	14		/* timestamp reply */
#define	ICMP_IREQ		15		/* information request */
#define	ICMP_IREQREPLY		16		/* information reply */
#define	ICMP_MASKREQ		17		/* address mask request */
#define	ICMP_MASKREPLY		18		/* address mask reply */

#define	ICMP_MAXTYPE		18

/* UNREACH codes */
#define	ICMP_UNREACH_NET	        0	/* bad net */
#define	ICMP_UNREACH_HOST	        1	/* bad host */
#define	ICMP_UNREACH_PROTOCOL	        2	/* bad protocol */
#define	ICMP_UNREACH_PORT	        3	/* bad port */
#define	ICMP_UNREACH_NEEDFRAG	        4	/* IP_DF caused drop */
#define	ICMP_UNREACH_SRCFAIL	        5	/* src route failed */
#define	ICMP_UNREACH_NET_UNKNOWN        6	/* unknown net */
#define	ICMP_UNREACH_HOST_UNKNOWN       7	/* unknown host */
#define	ICMP_UNREACH_ISOLATED	        8	/* src host isolated */
#define	ICMP_UNREACH_NET_PROHIB	        9	/* net denied */
#define	ICMP_UNREACH_HOST_PROHIB        10	/* host denied */
#define	ICMP_UNREACH_TOSNET	        11	/* bad tos for net */
#define	ICMP_UNREACH_TOSHOST	        12	/* bad tos for host */
#define	ICMP_UNREACH_FILTER_PROHIB      13	/* admin prohib */
#define	ICMP_UNREACH_HOST_PRECEDENCE    14	/* host prec vio. */
#define	ICMP_UNREACH_PRECEDENCE_CUTOFF  15	/* prec cutoff */

/* REDIRECT codes */
#define	ICMP_REDIRECT_NET	0		/* for network */
#define	ICMP_REDIRECT_HOST	1		/* for host */
#define	ICMP_REDIRECT_TOSNET	2		/* for tos and net */
#define	ICMP_REDIRECT_TOSHOST	3		/* for tos and host */

/* TIMEXCEED codes */
#define	ICMP_TIMXCEED_INTRANS	0		/* ttl==0 in transit */
#define	ICMP_TIMXCEED_REASS	1		/* ttl==0 in reass */

/* PARAMPROB code */
#define	ICMP_PARAMPROB_OPTABSENT 1		/* req. opt. absent */

#define	ICMP_INFOTYPE(type) \
	((type) == ICMP_ECHOREPLY || (type) == ICMP_ECHO || \
	(type) == ICMP_ROUTERADVERT || (type) == ICMP_ROUTERSOLICIT || \
	(type) == ICMP_TSTAMP || (type) == ICMP_TSTAMPREPLY || \
	(type) == ICMP_IREQ || (type) == ICMP_IREQREPLY || \
	(type) == ICMP_MASKREQ || (type) == ICMP_MASKREPLY)

#endif
