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 * $FreeBSD$ 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) 59 #if defined(IPVERSION) && (IPVERSION == 4) 60 static __inline u_int 61 in_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 87 static __inline void 88 in_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 96 static __inline u_short 97 in_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 } 108 109 static __inline u_short 110 in_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) 141 #if defined(IPVERSION) && (IPVERSION == 4) 142 u_int in_cksum_hdr(const struct ip *ip); 143 #endif 144 u_short in_addword(u_short sum, u_short b); 145 u_short in_pseudo(u_int sum, u_int b, u_int c); 146 #endif 147 u_short in_cksum_skip(struct mbuf *m, int len, int skip); 148 #endif /* _KERNEL */ 149 150 #endif /* _MACHINE_IN_CKSUM_H_ */ 151