usr/src/sys/netinet/udp.h

/*
 * Copyright (c) 1982, 1986 Regents of the University of California.
 * All rights reserved.
 *
 * %sccs.include.redist.c%
 *
 *      @(#)udp.h       7.4 (Berkeley) %G%
 */

/*
 * Udp protocol header.
 * Per RFC 768, September, 1981.
 */
struct udphdr {
        u_short uh_sport;               /* source port */
        u_short uh_dport;               /* destination port */
        short   uh_ulen;                /* udp length */
        u_short uh_sum;                 /* udp checksum */
};