1 /* 2 * Copyright (c) 2003,2004 The DragonFly Project. All rights reserved. 3 * 4 * This code is derived from software contributed to The DragonFly Project 5 * by Matthew Dillon <dillon@backplane.com> 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 * 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in 15 * the documentation and/or other materials provided with the 16 * distribution. 17 * 3. Neither the name of The DragonFly Project nor the names of its 18 * contributors may be used to endorse or promote products derived 19 * from this software without specific, prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 24 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 25 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 26 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 27 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 28 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 29 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 30 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 31 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * (note: completely rewritten for DragonFly) 35 * 36 * from tahoe: in_cksum.c 1.2 86/01/05 37 * from: @(#)in_cksum.c 1.3 (Berkeley) 1/19/91 38 * from: Id: in_cksum.c,v 1.8 1995/12/03 18:35:19 bde Exp 39 * $FreeBSD: src/sys/i386/include/in_cksum.h,v 1.7.2.2 2002/07/02 04:03:04 jdp Exp $ 40 */ 41 42 #ifndef _SYS_IN_CKSUM_H_ 43 #define _SYS_IN_CKSUM_H_ 44 45 #ifndef _SYS_TYPES_H_ 46 #include <sys/types.h> 47 #endif 48 #include <machine/stdint.h> 49 50 #ifdef _KERNEL 51 52 struct ip; 53 struct mbuf; 54 55 __uint32_t in_cksum_range(struct mbuf *m, int nxt, int offset, int bytes); 56 __uint32_t asm_ones32(const void *buf, int count); /* in 32 bit words */ 57 58 static __inline u_int 59 in_cksum(struct mbuf *m, int len) 60 { 61 return(in_cksum_range(m, 0, 0, len)); 62 } 63 64 static __inline u_int 65 in_cksum_skip(struct mbuf *m, int len, int skip) 66 { 67 return(in_cksum_range(m, 0, skip, len - skip)); 68 } 69 70 static __inline u_int 71 in_cksum_hdr(const struct ip *ip) 72 { 73 __uint32_t sum; 74 75 sum = asm_ones32((const void *)ip, 5); /* 5x4 = 20 bytes */ 76 sum = (sum >> 16) + (sum & 0xFFFF); 77 if (sum > 0xFFFF) 78 ++sum; 79 return(~sum & 0xFFFF); 80 } 81 82 #endif 83 84 static __inline u_short 85 in_addword(u_short sum, u_short b) 86 { 87 /* __volatile is necessary because the condition codes are used. */ 88 __asm __volatile ("addw %1, %0; adcw $0,%0" : "+r" (sum) : "r" (b)); 89 90 return (sum); 91 } 92 93 static __inline u_short 94 in_pseudo(u_int sum, u_int b, u_int c) 95 { 96 /* __volatile is necessary because the condition codes are used. */ 97 __asm __volatile ("addl %1,%0; adcl %2,%0; adcl $0,%0" 98 : "+r" (sum) 99 : "g" (b), "g" (c)); 100 sum = (sum & 0xffff) + (sum >> 16); 101 if (sum > 0xffff) 102 sum -= 0xffff; 103 return (sum); 104 } 105 106 #endif /* _MACHINE_IN_CKSUM_H_ */ 107