/* User Datagram Protocol definitions */

#define	NUDP	20

/* Structure of a UDP protocol header */
struct udp_header {
	int16 source;	/* Source port */
	int16 dest;	/* Destination port */
	int16 length;	/* Length of header and data */
	int16 checksum;	/* Checksum over pseudo-header, header and data */
};

/* User Datagram Protocol control block
 * Each entry on the receive queue consists of the
 * remote socket structure, followed by any data
 */
struct udp_cb {
	struct udp_cb *prev;	/* Linked list pointers */
	struct udp_cb *next;
	struct socket socket;	/* Local port accepting datagrams */
	void (*r_upcall)();	/* Function to call when one arrives */
	struct mbuf *rcvq;	/* Queue of pending datagrams */
	int rcvcnt;		/* Count of pending datagrams */
};
extern struct udp_cb *udps[];	/* Hash table for UDP structures */
#define	NULLUDP	(struct udp_cb *)NULL

/* UDP statistics counters */
struct udp_stat {
	int16 rcvd;		/* Packets received */
	int16 sent;		/* Packets sent */
	int16 cksum;		/* Checksum errors */
	int16 unknown;		/* Unknown socket */
	int16 bdcsts;		/* Incoming broadcasts */
};

/* UDP primitives */
int open_udp(),recv_udp(),send_udp(),del_udp();
void udp_dump();