in_cksum.h revision 330897
1/*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1990 The Regents of the University of California. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * from tahoe: in_cksum.c 1.2 86/01/05 32 * from: @(#)in_cksum.c 1.3 (Berkeley) 1/19/91 33 * from: Id: in_cksum.c,v 1.8 1995/12/03 18:35:19 bde Exp 34 * $FreeBSD: stable/11/sys/i386/include/in_cksum.h 330897 2018-03-14 03:19:51Z eadler $ 35 */ 36 37#ifndef _MACHINE_IN_CKSUM_H_ 38#define _MACHINE_IN_CKSUM_H_ 1 39 40#ifndef _SYS_CDEFS_H_ 41#error this file needs sys/cdefs.h as a prerequisite 42#endif 43 44/* 45 * MP safe (alfred) 46 */ 47 48#include <sys/cdefs.h> 49 50#define in_cksum(m, len) in_cksum_skip(m, len, 0) 51 52/* 53 * It it useful to have an Internet checksum routine which is inlineable 54 * and optimized specifically for the task of computing IP header checksums 55 * in the normal case (where there are no options and the header length is 56 * therefore always exactly five 32-bit words. 57 */ 58#if defined(__GNUCLIKE_ASM) && !defined(__INTEL_COMPILER) 59#if defined(IPVERSION) && (IPVERSION == 4) 60static __inline u_int 61in_cksum_hdr(const struct ip *ip) 62{ 63 u_int sum = 0; 64 65 __asm( 66 "addl %1, %0\n" 67 "adcl %2, %0\n" 68 "adcl %3, %0\n" 69 "adcl %4, %0\n" 70 "adcl %5, %0\n" 71 "adcl $0, %0" 72 : "+r" (sum) 73 : "g" (((const u_int32_t *)ip)[0]), 74 "g" (((const u_int32_t *)ip)[1]), 75 "g" (((const u_int32_t *)ip)[2]), 76 "g" (((const u_int32_t *)ip)[3]), 77 "g" (((const u_int32_t *)ip)[4]) 78 : "cc" 79 ); 80 sum = (sum & 0xffff) + (sum >> 16); 81 if (sum > 0xffff) 82 sum -= 0xffff; 83 84 return ~sum & 0xffff; 85} 86 87static __inline void 88in_cksum_update(struct ip *ip) 89{ 90 int __tmpsum; 91 __tmpsum = (int)ntohs(ip->ip_sum) + 256; 92 ip->ip_sum = htons(__tmpsum + (__tmpsum >> 16)); 93} 94#endif 95 96static __inline u_short 97in_addword(u_short sum, u_short b) 98{ 99 __asm( 100 "addw %1, %0\n" 101 "adcw $0, %0" 102 : "+r" (sum) 103 : "g" (b) 104 : "cc" 105 ); 106 return (sum); 107} 108 109static __inline u_short 110in_pseudo(u_int sum, u_int b, u_int c) 111{ 112 __asm( 113 "addl %1, %0\n" 114 "adcl %2, %0\n" 115 "adcl $0, %0" 116 : "+r" (sum) 117 : "g" (b), 118 "g" (c) 119 : "cc" 120 ); 121 sum = (sum & 0xffff) + (sum >> 16); 122 if (sum > 0xffff) 123 sum -= 0xffff; 124 return (sum); 125} 126 127#else 128#if defined(IPVERSION) && (IPVERSION == 4) 129#define in_cksum_update(ip) \ 130 do { \ 131 int __tmpsum; \ 132 __tmpsum = (int)ntohs(ip->ip_sum) + 256; \ 133 ip->ip_sum = htons(__tmpsum + (__tmpsum >> 16)); \ 134 } while(0) 135 136#endif 137#endif 138 139#ifdef _KERNEL 140#if !defined(__GNUCLIKE_ASM) || defined(__INTEL_COMPILER) 141#if defined(IPVERSION) && (IPVERSION == 4) 142u_int in_cksum_hdr(const struct ip *ip); 143#endif 144u_short in_addword(u_short sum, u_short b); 145u_short in_pseudo(u_int sum, u_int b, u_int c); 146#endif 147u_short in_cksum_skip(struct mbuf *m, int len, int skip); 148#endif /* _KERNEL */ 149 150#endif /* _MACHINE_IN_CKSUM_H_ */ 151