/*
 * File:		ip.h
 * Purpose:		Definitions for the Internet Protocol, IP.
 *
 * Notes:		See RFC 791 "DARPA Internet Program Protocol
 *				Specification" for more details.
 *
 * Author:		Eric DeVolder
 * Date:		11-8-95
 *
 * Modifications:
 *
 */

#ifndef _IP_H
#define _IP_H

/********************************************************************/

/* 32-bit IP Addresses */
typedef uint8 IP_ADDR[4];

/* Pointer to an IP Address */
typedef uint8 IP_ADDR_P[];

/* Definition of an IP packet header */
typedef struct
{
	uint8		version_ihl;
	uint8		service_type;
	uint16		total_length;
	uint16		identification;
	uint16		flags_frag_offset;
	uint8		ttl;
	uint8		protocol;
	uint16		checksum;
	IP_ADDR		source_addr;
	IP_ADDR		dest_addr;
	uint8		options;	/* actually an array of undetermined length */
} ip_frame_hdr;

/* Macros for accessing an IP datagram.  */
#define IP_VERSION(a)	((a->version_ihl & 0x00F0) >> 4)
#define IP_IHL(a)		((a->version_ihl & 0x000F))
#define IP_SERVICE(a)	(a->service_type)
#define IP_LENGTH(a)	(a->total_length)
#define IP_IDENT(a)		(a->identification)
#define IP_FLAGS(a)		((a->flags_frag_offset & 0x0000E000) >> 13)
#define IP_FRAGMENT(a)	((a->flags_frag_offset & 0x00001FFF))
#define IP_TTL(a)		(a->ttl)
#define IP_PROTOCOL(a)	(a->protocol)
#define IP_CHKSUM(a)	(a->checksum)
#define IP_SRC(a)		(&a->source_addr[0])
#define IP_DEST(a)		(&a->dest_addr[0])
#define IP_OPTIONS(a)	(&a->options)
#define IP_DATA(a)		(&((uint8 *)a)[IP_IHL(a) * 4])

/* Defined IP protocols */
#define IP_PROTO_ICMP	(1)
#define IP_PROTO_UDP	(17)

/* Protocol Header information */
#define IP_HDR_OFFSET	ETH_HDR_SIZE
#define IP_HDR_SIZE		20	/* no options */

/********************************************************************/

typedef struct
{
	IP_ADDR			myip;
	IP_ADDR			gateway;
	IP_ADDR			netmask;
	IP_ADDR			broadcast;
	unsigned int	rx;
	unsigned int	rx_unsup;
	unsigned int	tx;
	unsigned int	err;
} IP_INFO;

/********************************************************************/

void
ip_handler (NIF *, NBUF *);

uint16
ip_chksum (uint16 *, int);

int
ip_send (NIF *, 
		uint8 *,	/* destination IP */
		uint8 *,	/* source IP */
		uint8,		/* protocol */
		NBUF *		/* buffer descriptor */);

void
ip_init (IP_INFO *, IP_ADDR_P, IP_ADDR_P, IP_ADDR_P);

uint8 *
ip_get_myip (IP_INFO *);

uint8 *
ip_resolve_route (NIF *, IP_ADDR_P, NBUF **);

/********************************************************************/

#endif 	/* _IP_H */