/* udp.h */

/* EMACS_MODES: c !fill */


/* Definitions for User Datagram Protocol packets */

#include	<ip.h>

struct	udp	{
	unshort	ud_srcp;		/* source port */
	unshort	ud_dstp;		/* dest. port */
	unshort	ud_len;			/* length */
	unshort	ud_cksum;		/* checksum */
};

/* The UDP pseudo-header */

struct	udpph	{
	in_name	ph_src;			/* source address */
	in_name	ph_dest;		/* dest. address */
	char	ph_zero;		/* reserved */
	char	ph_prot;		/* protocol */
	unshort	ph_len;			/* udp length */
};

/* Useful Constants */

#define	UDPPROT		17		/* UDP protocol number */
#define	BIGCKSUM	30		/* breakeven size for fast cksummer */


/* Externals */

extern	caddr_t	udp_alloc();

/* Useful Macros */

/* Return a pointer to the udp header of a udp packet */
#define	udp_head(pip)	((struct udp *)in_data((pip)))

/* Return a pointer to the data portion of a udp packet */
#define	udp_data(pup) 	((caddr_t)(pup) + sizeof (struct udp))