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 */ 35 36 #ifndef _MACHINE_IN_CKSUM_H_ 37 #define _MACHINE_IN_CKSUM_H_ 1 38 39 #include <sys/cdefs.h> 40 41 #define in_cksum(m, len) in_cksum_skip(m, len, 0) 42 43 /* 44 * It it useful to have an Internet checksum routine which is inlineable 45 * and optimized specifically for the task of computing IP header checksums 46 * in the normal case (where there are no options and the header length is 47 * therefore always exactly five 32-bit words. 48 */ 49 #if defined(IPVERSION) && (IPVERSION == 4) 50 static __inline u_int 51 in_cksum_hdr(const struct ip *ip) 52 { 53 u_int sum = 0; 54 55 __asm( 56 "addl %1, %0\n" 57 "adcl %2, %0\n" 58 "adcl %3, %0\n" 59 "adcl %4, %0\n" 60 "adcl %5, %0\n" 61 "adcl $0, %0" 62 : "+r" (sum) 63 : "g" (((const u_int32_t *)ip)[0]), 64 "g" (((const u_int32_t *)ip)[1]), 65 "g" (((const u_int32_t *)ip)[2]), 66 "g" (((const u_int32_t *)ip)[3]), 67 "g" (((const u_int32_t *)ip)[4]) 68 : "cc" 69 ); 70 sum = (sum & 0xffff) + (sum >> 16); 71 if (sum > 0xffff) 72 sum -= 0xffff; 73 74 return ~sum & 0xffff; 75 } 76 #endif 77 78 static __inline u_short 79 in_addword(u_short sum, u_short b) 80 { 81 __asm( 82 "addw %1, %0\n" 83 "adcw $0, %0" 84 : "+r" (sum) 85 : "g" (b) 86 : "cc" 87 ); 88 return (sum); 89 } 90 91 static __inline u_short 92 in_pseudo(u_int sum, u_int b, u_int c) 93 { 94 __asm( 95 "addl %1, %0\n" 96 "adcl %2, %0\n" 97 "adcl $0, %0" 98 : "+r" (sum) 99 : "g" (b), 100 "g" (c) 101 : "cc" 102 ); 103 sum = (sum & 0xffff) + (sum >> 16); 104 if (sum > 0xffff) 105 sum -= 0xffff; 106 return (sum); 107 } 108 109 #ifdef _KERNEL 110 111 #define HAVE_MD_IN_CKSUM 112 113 u_short in_cksum_skip(struct mbuf *m, int len, int skip); 114 #endif /* _KERNEL */ 115 116 #endif /* _MACHINE_IN_CKSUM_H_ */ 117