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 #include <sys/cdefs.h> 41 42 #define in_cksum(m, len) in_cksum_skip(m, len, 0) 43 44 /* 45 * It it useful to have an Internet checksum routine which is inlineable 46 * and optimized specifically for the task of computing IP header checksums 47 * in the normal case (where there are no options and the header length is 48 * therefore always exactly five 32-bit words. 49 */ 50 #if defined(IPVERSION) && (IPVERSION == 4) 51 static __inline u_int 52 in_cksum_hdr(const struct ip *ip) 53 { 54 u_int sum = 0; 55 56 __asm( 57 "addl %1, %0\n" 58 "adcl %2, %0\n" 59 "adcl %3, %0\n" 60 "adcl %4, %0\n" 61 "adcl %5, %0\n" 62 "adcl $0, %0" 63 : "+r" (sum) 64 : "g" (((const u_int32_t *)ip)[0]), 65 "g" (((const u_int32_t *)ip)[1]), 66 "g" (((const u_int32_t *)ip)[2]), 67 "g" (((const u_int32_t *)ip)[3]), 68 "g" (((const u_int32_t *)ip)[4]) 69 : "cc" 70 ); 71 sum = (sum & 0xffff) + (sum >> 16); 72 if (sum > 0xffff) 73 sum -= 0xffff; 74 75 return ~sum & 0xffff; 76 } 77 #endif 78 79 static __inline u_short 80 in_addword(u_short sum, u_short b) 81 { 82 __asm( 83 "addw %1, %0\n" 84 "adcw $0, %0" 85 : "+r" (sum) 86 : "g" (b) 87 : "cc" 88 ); 89 return (sum); 90 } 91 92 static __inline u_short 93 in_pseudo(u_int sum, u_int b, u_int c) 94 { 95 __asm( 96 "addl %1, %0\n" 97 "adcl %2, %0\n" 98 "adcl $0, %0" 99 : "+r" (sum) 100 : "g" (b), 101 "g" (c) 102 : "cc" 103 ); 104 sum = (sum & 0xffff) + (sum >> 16); 105 if (sum > 0xffff) 106 sum -= 0xffff; 107 return (sum); 108 } 109 110 #ifdef _KERNEL 111 112 #define HAVE_MD_IN_CKSUM 113 114 u_short in_cksum_skip(struct mbuf *m, int len, int skip); 115 #endif /* _KERNEL */ 116 117 #endif /* _MACHINE_IN_CKSUM_H_ */ 118