usr/src/sys/netinet/udp.h

/*
 * Copyright (c) 1982, 1986 Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms are permitted
 * provided that this notice is preserved and that due credit is given
 * to the University of California at Berkeley. The name of the University
 * may not be used to endorse or promote products derived from this
 * software without specific prior written permission. This software
 * is provided ``as is'' without express or implied warranty.
 *
 *      @(#)udp.h       7.2 (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 */
};