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 /* 39 * MP safe (alfred) 40 */ 41 42 #include <sys/cdefs.h> 43 44 #define in_cksum(m, len) in_cksum_skip(m, len, 0) 45 46 /* 47 * It it useful to have an Internet checksum routine which is inlineable 48 * and optimized specifically for the task of computing IP header checksums 49 * in the normal case (where there are no options and the header length is 50 * therefore always exactly five 32-bit words. 51 */ 52 #if defined(__GNUC__) && !defined(__INTEL_COMPILER) 53 static __inline u_int 54 in_cksum_hdr(const struct ip *ip) 55 { 56 register u_int sum = 0; 57 58 __asm __volatile ( 59 "addl %1, %0\n" 60 "adcl %2, %0\n" 61 "adcl %3, %0\n" 62 "adcl %4, %0\n" 63 "adcl %5, %0\n" 64 "adcl $0, %0" 65 : "+r" (sum) 66 : "g" (((const u_int32_t *)ip)[0]), 67 "g" (((const u_int32_t *)ip)[1]), 68 "g" (((const u_int32_t *)ip)[2]), 69 "g" (((const u_int32_t *)ip)[3]), 70 "g" (((const u_int32_t *)ip)[4]) 71 ); 72 sum = (sum & 0xffff) + (sum >> 16); 73 if (sum > 0xffff) 74 sum -= 0xffff; 75 76 return ~sum & 0xffff; 77 } 78 79 static __inline void 80 in_cksum_update(struct ip *ip) 81 { 82 int __tmpsum; 83 __tmpsum = (int)ntohs(ip->ip_sum) + 256; 84 ip->ip_sum = htons(__tmpsum + (__tmpsum >> 16)); 85 } 86 87 static __inline u_short 88 in_addword(u_short sum, u_short b) 89 { 90 /* __volatile is necessary because the condition codes are used. */ 91 __asm __volatile ("addw %1, %0" : "+r" (sum) : "r" (b)); 92 __asm __volatile ("adcw $0, %0" : "+r" (sum)); 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 /* __volatile is necessary because the condition codes are used. */ 101 __asm __volatile ("addl %1, %0" : "+r" (sum) : "g" (b)); 102 __asm __volatile ("adcl %1, %0" : "+r" (sum) : "g" (c)); 103 __asm __volatile ("adcl $0, %0" : "+r" (sum)); 104 105 sum = (sum & 0xffff) + (sum >> 16); 106 if (sum > 0xffff) 107 sum -= 0xffff; 108 return (sum); 109 } 110 111 #else 112 #define in_cksum_update(ip) \ 113 do { \ 114 int __tmpsum; \ 115 __tmpsum = (int)ntohs(ip->ip_sum) + 256; \ 116 ip->ip_sum = htons(__tmpsum + (__tmpsum >> 16)); \ 117 } while(0) 118 119 #endif 120 121 #ifdef _KERNEL 122 #if !defined(__GNUC__) || defined(__INTEL_COMPILER) 123 u_int in_cksum_hdr(const struct ip *ip); 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