in_cksum.h revision 285830
1/*- 2 * Copyright (c) 1990 The Regents of the University of California. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 4. Neither the name of the University nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * from tahoe: in_cksum.c 1.2 86/01/05 30 * from: @(#)in_cksum.c 1.3 (Berkeley) 1/19/91 31 * from: Id: in_cksum.c,v 1.8 1995/12/03 18:35:19 bde Exp 32 * $FreeBSD: releng/10.2/sys/amd64/include/in_cksum.h 235941 2012-05-24 22:00:48Z bz $ 33 */ 34 35#ifndef _MACHINE_IN_CKSUM_H_ 36#define _MACHINE_IN_CKSUM_H_ 1 37 38#ifndef _SYS_CDEFS_H_ 39#error this file needs sys/cdefs.h as a prerequisite 40#endif 41 42#include <sys/cdefs.h> 43 44#define in_cksum(m, len) in_cksum_skip(m, len, 0) 45 46#if defined(IPVERSION) && (IPVERSION == 4) 47/* 48 * It it useful to have an Internet checksum routine which is inlineable 49 * and optimized specifically for the task of computing IP header checksums 50 * in the normal case (where there are no options and the header length is 51 * therefore always exactly five 32-bit words. 52 */ 53#ifdef __CC_SUPPORTS___INLINE 54 55static __inline void 56in_cksum_update(struct ip *ip) 57{ 58 int __tmpsum; 59 __tmpsum = (int)ntohs(ip->ip_sum) + 256; 60 ip->ip_sum = htons(__tmpsum + (__tmpsum >> 16)); 61} 62 63#else 64 65#define in_cksum_update(ip) \ 66 do { \ 67 int __tmpsum; \ 68 __tmpsum = (int)ntohs(ip->ip_sum) + 256; \ 69 ip->ip_sum = htons(__tmpsum + (__tmpsum >> 16)); \ 70 } while(0) 71 72#endif 73#endif 74 75#ifdef _KERNEL 76#if defined(IPVERSION) && (IPVERSION == 4) 77u_int in_cksum_hdr(const struct ip *ip); 78#endif 79u_short in_addword(u_short sum, u_short b); 80u_short in_pseudo(u_int sum, u_int b, u_int c); 81u_short in_cksum_skip(struct mbuf *m, int len, int skip); 82#endif 83 84#endif /* _MACHINE_IN_CKSUM_H_ */ 85