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 * $FreeBSD$ 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 /* 43 * MP safe (alfred) 44 */ 45 46 #include <sys/cdefs.h> 47 48 #define in_cksum(m, len) in_cksum_skip(m, len, 0) 49 50 /* 51 * It it useful to have an Internet checksum routine which is inlineable 52 * and optimized specifically for the task of computing IP header checksums 53 * in the normal case (where there are no options and the header length is 54 * therefore always exactly five 32-bit words. 55 */ 56 #if defined(__GNUCLIKE_ASM) && !defined(__INTEL_COMPILER) 57 #if defined(IPVERSION) && (IPVERSION == 4) 58 static __inline u_int 59 in_cksum_hdr(const struct ip *ip) 60 { 61 u_int sum = 0; 62 63 __asm( 64 "addl %1, %0\n" 65 "adcl %2, %0\n" 66 "adcl %3, %0\n" 67 "adcl %4, %0\n" 68 "adcl %5, %0\n" 69 "adcl $0, %0" 70 : "+r" (sum) 71 : "g" (((const u_int32_t *)ip)[0]), 72 "g" (((const u_int32_t *)ip)[1]), 73 "g" (((const u_int32_t *)ip)[2]), 74 "g" (((const u_int32_t *)ip)[3]), 75 "g" (((const u_int32_t *)ip)[4]) 76 : "cc" 77 ); 78 sum = (sum & 0xffff) + (sum >> 16); 79 if (sum > 0xffff) 80 sum -= 0xffff; 81 82 return ~sum & 0xffff; 83 } 84 85 static __inline void 86 in_cksum_update(struct ip *ip) 87 { 88 int __tmpsum; 89 __tmpsum = (int)ntohs(ip->ip_sum) + 256; 90 ip->ip_sum = htons(__tmpsum + (__tmpsum >> 16)); 91 } 92 #endif 93 94 static __inline u_short 95 in_addword(u_short sum, u_short b) 96 { 97 __asm( 98 "addw %1, %0\n" 99 "adcw $0, %0" 100 : "+r" (sum) 101 : "g" (b) 102 : "cc" 103 ); 104 return (sum); 105 } 106 107 static __inline u_short 108 in_pseudo(u_int sum, u_int b, u_int c) 109 { 110 __asm( 111 "addl %1, %0\n" 112 "adcl %2, %0\n" 113 "adcl $0, %0" 114 : "+r" (sum) 115 : "g" (b), 116 "g" (c) 117 : "cc" 118 ); 119 sum = (sum & 0xffff) + (sum >> 16); 120 if (sum > 0xffff) 121 sum -= 0xffff; 122 return (sum); 123 } 124 125 #else 126 #if defined(IPVERSION) && (IPVERSION == 4) 127 #define in_cksum_update(ip) \ 128 do { \ 129 int __tmpsum; \ 130 __tmpsum = (int)ntohs(ip->ip_sum) + 256; \ 131 ip->ip_sum = htons(__tmpsum + (__tmpsum >> 16)); \ 132 } while(0) 133 134 #endif 135 #endif 136 137 #ifdef _KERNEL 138 #if !defined(__GNUCLIKE_ASM) || defined(__INTEL_COMPILER) 139 #if defined(IPVERSION) && (IPVERSION == 4) 140 u_int in_cksum_hdr(const struct ip *ip); 141 #endif 142 u_short in_addword(u_short sum, u_short b); 143 u_short in_pseudo(u_int sum, u_int b, u_int c); 144 #endif 145 u_short in_cksum_skip(struct mbuf *m, int len, int skip); 146 #endif /* _KERNEL */ 147 148 #endif /* _MACHINE_IN_CKSUM_H_ */ 149