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 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * from tahoe: in_cksum.c 1.2 86/01/05 34 * from: @(#)in_cksum.c 1.3 (Berkeley) 1/19/91 35 * from: Id: in_cksum.c,v 1.8 1995/12/03 18:35:19 bde Exp 36 * $FreeBSD$ 37 */ 38 39 #ifndef _MACHINE_IN_CKSUM_H_ 40 #define _MACHINE_IN_CKSUM_H_ 1 41 42 /* 43 * MP safe (alfred) 44 */ 45 46 #include <sys/cdefs.h> 47 48 #define in_cksum(m, len) in_cksum_skip(m, len, 0) 49 50 /* 51 * It it useful to have an Internet checksum routine which is inlineable 52 * and optimized specifically for the task of computing IP header checksums 53 * in the normal case (where there are no options and the header length is 54 * therefore always exactly five 32-bit words. 55 */ 56 #ifdef __GNUC__ 57 static __inline u_int 58 in_cksum_hdr(const struct ip *ip) 59 { 60 register u_int sum = 0; 61 62 #define ADD(n) __asm("addl " #n "(%1), %0" : "+r" (sum) : "r" (ip)) 63 #define ADDC(n) __asm("adcl " #n "(%1), %0" : "+r" (sum) : "r" (ip)) 64 #define MOP __asm("adcl $0, %0" : "+r" (sum)) 65 66 ADD(0); 67 ADDC(4); 68 ADDC(8); 69 ADDC(12); 70 ADDC(16); 71 MOP; 72 #undef ADD 73 #undef ADDC 74 #undef MOP 75 sum = (sum & 0xffff) + (sum >> 16); 76 if (sum > 0xffff) 77 sum -= 0xffff; 78 79 return ~sum & 0xffff; 80 } 81 82 static __inline void 83 in_cksum_update(struct ip *ip) 84 { 85 int __tmpsum; 86 __tmpsum = (int)ntohs(ip->ip_sum) + 256; 87 ip->ip_sum = htons(__tmpsum + (__tmpsum >> 16)); 88 } 89 90 static __inline u_short 91 in_addword(u_short sum, u_short b) 92 { 93 94 __asm("addw %1, %0" : "+r" (sum) : "r" (b)); 95 __asm("adcw $0, %0" : "+r" (sum)); 96 97 return (sum); 98 } 99 100 static __inline u_short 101 in_pseudo(u_int sum, u_int b, u_int c) 102 { 103 104 __asm("addl %1, %0" : "+r" (sum) : "r" (b)); 105 __asm("adcl %1, %0" : "+r" (sum) : "r" (c)); 106 __asm("adcl $0, %0" : "+r" (sum)); 107 108 sum = (sum & 0xffff) + (sum >> 16); 109 if (sum > 0xffff) 110 sum -= 0xffff; 111 return (sum); 112 } 113 114 #else 115 u_int in_cksum_hdr(const struct ip *); 116 #define in_cksum_update(ip) \ 117 do { \ 118 int __tmpsum; \ 119 __tmpsum = (int)ntohs(ip->ip_sum) + 256; \ 120 ip->ip_sum = htons(__tmpsum + (__tmpsum >> 16)); \ 121 } while(0) 122 123 #endif 124 125 #ifdef _KERNEL 126 u_short in_cksum_skip(struct mbuf *m, int len, int skip); 127 #endif /* _KERNEL */ 128 129 #endif /* _MACHINE_IN_CKSUM_H_ */ 130