2 * Copyright (c) 1995, Mike Mitchell
3 * Copyright (c) 1982, 1992, 1993
4 * The Regents of the University of California. All rights reserved.
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 4. Neither the name of the University nor the names of its contributors
15 * may be used to endorse or promote products derived from this software
16 * without specific prior written permission.
18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * $FreeBSD: src/sys/netipx/ipx_cksum.c,v 1.9 1999/08/28 18:21:53 jhay Exp $
33 * $DragonFly: src/sys/netproto/ipx/ipx_cksum.c,v 1.4 2005/02/15 18:11:59 joerg Exp $
36 #include <sys/param.h>
38 #include <sys/libkern.h>
44 #define SUMADV sum += *w++
47 ipx_cksum(struct mbuf *m, int len) {
58 ipx = mtod(m, struct ipx*);
66 mlen = imin(m->m_len - mlen, len);
70 SUMADV; SUMADV; SUMADV; SUMADV;
71 SUMADV; SUMADV; SUMADV; SUMADV;
72 SUMADV; SUMADV; SUMADV; SUMADV;
73 SUMADV; SUMADV; SUMADV; SUMADV;
82 buf.b[0] = *(u_char*)w;
92 w = mtod(m, u_short*);
94 buf.b[1] = *(u_char*)w;
96 w = (uint16_t *)((uint8_t *)w + 1);
104 sum = (sum & 0xffff) + (sum >> 16);