1/* $OpenBSD: in4_cksum.c,v 1.7 2003/06/02 23:28:13 millert Exp $ */ 2/* $KAME: in4_cksum.c,v 1.10 2001/11/30 10:06:15 itojun Exp $ */ 3/* $NetBSD: in_cksum.c,v 1.13 1996/10/13 02:03:03 christos Exp $ */ 4 5/*- 6 * SPDX-License-Identifier: BSD-3-Clause 7 * 8 * Copyright (C) 1999 WIDE Project. 9 * All rights reserved. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. Neither the name of the project nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36/* 37 * Copyright (c) 1988, 1992, 1993 38 * The Regents of the University of California. All rights reserved. 39 * 40 * Redistribution and use in source and binary forms, with or without 41 * modification, are permitted provided that the following conditions 42 * are met: 43 * 1. Redistributions of source code must retain the above copyright 44 * notice, this list of conditions and the following disclaimer. 45 * 2. Redistributions in binary form must reproduce the above copyright 46 * notice, this list of conditions and the following disclaimer in the 47 * documentation and/or other materials provided with the distribution. 48 * 3. Neither the name of the University nor the names of its contributors 49 * may be used to endorse or promote products derived from this software 50 * without specific prior written permission. 51 * 52 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 53 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 54 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 55 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 56 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 57 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 58 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 59 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 60 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 61 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 62 * SUCH DAMAGE. 63 */ 64 65#include <sys/param.h> 66#include <sys/systm.h> 67#include <sys/mbuf.h> 68 69#include <netinet/in.h> 70#include <netinet/in_systm.h> 71#include <netinet/ip.h> 72#include <netinet/ip_var.h> 73 74#include <machine/in_cksum.h> 75 76#define ADDCARRY(x) (x > 65535 ? x -= 65535 : x) 77#define REDUCE {l_util.l = sum; sum = l_util.s[0] + l_util.s[1]; (void)ADDCARRY(sum);} 78 79int in4_cksum(struct mbuf *, u_int8_t, int, int); 80 81int 82in4_cksum(struct mbuf *m, u_int8_t nxt, int off, int len) 83{ 84 union { 85 struct ipovly ipov; 86 u_int16_t w[10]; 87 } u; 88 union { 89 u_int16_t s[2]; 90 u_int32_t l; 91 } l_util; 92 93 u_int16_t *w; 94 int psum; 95 int sum = 0; 96 97 if (nxt != 0) { 98 /* pseudo header */ 99 if (off < sizeof(struct ipovly)) 100 panic("in4_cksum: offset too short"); 101 if (m->m_len < sizeof(struct ip)) 102 panic("in4_cksum: bad mbuf chain"); 103 bzero(&u.ipov, sizeof(u.ipov)); 104 u.ipov.ih_len = htons(len); 105 u.ipov.ih_pr = nxt; 106 u.ipov.ih_src = mtod(m, struct ip *)->ip_src; 107 u.ipov.ih_dst = mtod(m, struct ip *)->ip_dst; 108 w = u.w; 109 /* assumes sizeof(ipov) == 20 */ 110 sum += w[0]; sum += w[1]; sum += w[2]; sum += w[3]; sum += w[4]; 111 sum += w[5]; sum += w[6]; sum += w[7]; sum += w[8]; sum += w[9]; 112 } 113 114 psum = in_cksum_skip(m, len + off, off); 115 psum = ~psum & 0xffff; 116 sum += psum; 117 REDUCE; 118 return (~sum & 0xffff); 119} 120