/* ip.h */

/* EMACS_MODES: c !fill */

/*
 * This file contains the structure definitions for internet headers.
 */

#include	<in_params.h>


/* Packet Data Length */

#define	INETLEN		576		/* max. size of inet pkt in bytes */

typedef	long	in_name;		/* an internet name */

struct	ip {
	int		ip_ihl : 4;	/* IN header length in 32 bit words */
	int		ip_ver : 4;	/* Header version */
	char		ip_tsrv;	/* Type of service */
	unshort		ip_len;		/* Total pkt length including header */
	unshort		ip_id;		/* ID to help fragmentation */
	unshort		ip_foff : 13;	/* Fragment offset */
	unshort		ip_flgs : 3;	/* Flags */
	char		ip_time;	/* Life time of packet in seconds */
	char		ip_prot;	/* Protocol number */
	unshort		ip_chksum;	/* Header checksum */
	in_name	ip_src;			/* Source name */
	in_name	ip_dest;		/* Destination name */
};

/* Constants to fill in Internet Header */

#define	IPHSIZ	sizeof( struct ip ) 	/* internet header size */
#define	IP_VER	4			/* internet version */
#define	IP_IHL	5			/* IN header length in longwords */
#define	IP_TSRV	0			/* default type of service */
#define	IP_ID	0			/* ==> kernel fills IN id */
#define	IP_FLGS	0			/* no fragmentation yet */
#define	IP_FOFF	0			/* no fragmentation yet */
#define	IP_TIME	255			/* max. possible time to live */
#define	CHKSUM 0			/* initial checksum value */
#define	MININSIZ 8			/* min. size of IN data area */


/* Fragmentation buffer information */

struct	frag	{			/* fragmentation info per connection */
	int	fg_size;		/* max. fragment size in bytes */
	caddr_t	fg_buf;			/* fragment buffer */
};


/* Macros to swap bytes */

#ifndef	BIGINDIAN
#define	short_to_net(s)	(swab (s))
#define	long_to_net(l)	(((long)(swab (*(unshort *)(&l))) << 16) | \
(swab (*(((unshort *)&l) + 1))))
#else
#define	short_to_net(s)	(s)
#define	long_to_net(l)	(l)
#endif

/* Other Internet macros - move address, etc. */

/* Return pointer to internet header of packet.  Takes pointer to packet */
#define	in_head(ppkt)	((struct ip *)((caddr_t)(ppkt) + lnhsiz))

/* Return pointer to start of packet data.  Takes pointer to internet header */
#define	in_data(pip)	((caddr_t)(pip) + ((pip)->ip_ihl << 2))

/* Return pointer to start of option string.  Takes pointer to IN header */
#define	in_options(pip)	((caddr_t)(pip) + (IP_IHL << 2))

/* Return length of option string in bytes.  Takes pointer to IN header */
#define	in_optlen(pip)	(((pip)->ip_ihl - IP_IHL) << 2)

#include	<in_extern.h>