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: Id: in_cksum.c,v 1.8 1995/12/03 18:35:19 bde Exp 33 */ 34 35 #ifndef _MACHINE_IN_CKSUM_H_ 36 #define _MACHINE_IN_CKSUM_H_ 1 37 38 #include <sys/cdefs.h> 39 40 #define in_cksum(m, len) in_cksum_skip(m, len, 0) 41 42 /* 43 * It it useful to have an Internet checksum routine which is inlineable 44 * and optimized specifically for the task of computing IP header checksums 45 * in the normal case (where there are no options and the header length is 46 * therefore always exactly five 32-bit words. 47 */ 48 #if defined(IPVERSION) && (IPVERSION == 4) 49 static __inline u_int 50 in_cksum_hdr(const struct ip *ip) 51 { 52 u_int sum = 0; 53 54 __asm( 55 "addl %1, %0\n" 56 "adcl %2, %0\n" 57 "adcl %3, %0\n" 58 "adcl %4, %0\n" 59 "adcl %5, %0\n" 60 "adcl $0, %0" 61 : "+r" (sum) 62 : "g" (((const u_int32_t *)ip)[0]), 63 "g" (((const u_int32_t *)ip)[1]), 64 "g" (((const u_int32_t *)ip)[2]), 65 "g" (((const u_int32_t *)ip)[3]), 66 "g" (((const u_int32_t *)ip)[4]) 67 : "cc" 68 ); 69 sum = (sum & 0xffff) + (sum >> 16); 70 if (sum > 0xffff) 71 sum -= 0xffff; 72 73 return ~sum & 0xffff; 74 } 75 #endif 76 77 static __inline u_short 78 in_addword(u_short sum, u_short b) 79 { 80 __asm( 81 "addw %1, %0\n" 82 "adcw $0, %0" 83 : "+r" (sum) 84 : "g" (b) 85 : "cc" 86 ); 87 return (sum); 88 } 89 90 static __inline u_short 91 in_pseudo(u_int sum, u_int b, u_int c) 92 { 93 __asm( 94 "addl %1, %0\n" 95 "adcl %2, %0\n" 96 "adcl $0, %0" 97 : "+r" (sum) 98 : "g" (b), 99 "g" (c) 100 : "cc" 101 ); 102 sum = (sum & 0xffff) + (sum >> 16); 103 if (sum > 0xffff) 104 sum -= 0xffff; 105 return (sum); 106 } 107 108 #ifdef _KERNEL 109 110 #define HAVE_MD_IN_CKSUM 111 112 u_short in_cksum_skip(struct mbuf *m, int len, int skip); 113 #endif /* _KERNEL */ 114 115 #endif /* _MACHINE_IN_CKSUM_H_ */ 116