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 * 3. All advertising materials mentioning features or use of this software
15 * must display the following acknowledgement:
16 * This product includes software developed by the University of
17 * California, Berkeley and its contributors.
18 * 4. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * $FreeBSD: src/sys/netipx/ipx_cksum.c,v 1.9 1999/08/28 18:21:53 jhay Exp $
37 * $DragonFly: src/sys/netproto/ipx/ipx_cksum.c,v 1.4 2005/02/15 18:11:59 joerg Exp $
40 #include <sys/param.h>
42 #include <sys/libkern.h>
48 #define SUMADV sum += *w++
51 ipx_cksum(struct mbuf *m, int len) {
62 ipx = mtod(m, struct ipx*);
70 mlen = imin(m->m_len - mlen, len);
74 SUMADV; SUMADV; SUMADV; SUMADV;
75 SUMADV; SUMADV; SUMADV; SUMADV;
76 SUMADV; SUMADV; SUMADV; SUMADV;
77 SUMADV; SUMADV; SUMADV; SUMADV;
86 buf.b[0] = *(u_char*)w;
96 w = mtod(m, u_short*);
98 buf.b[1] = *(u_char*)w;
100 w = (uint16_t *)((uint8_t *)w + 1);
108 sum = (sum & 0xffff) + (sum >> 16);