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