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 * $DragonFly: src/sys/sys/in_cksum.h,v 1.3 2004/09/19 22:32:48 joerg Exp $ 41 */ 42 43 #ifndef _SYS_IN_CKSUM_H_ 44 #define _SYS_IN_CKSUM_H_ 45 46 #ifdef _KERNEL 47 48 struct ip; 49 struct mbuf; 50 51 __uint32_t in_cksum_range(struct mbuf *m, int nxt, int offset, int bytes); 52 __uint32_t asm_ones32(const void *buf, int count); /* in 32 bit words */ 53 54 static __inline u_int 55 in_cksum(struct mbuf *m, int len) 56 { 57 return(in_cksum_range(m, 0, 0, len)); 58 } 59 60 static __inline u_int 61 in_cksum_skip(struct mbuf *m, int len, int skip) 62 { 63 return(in_cksum_range(m, 0, skip, len - skip)); 64 } 65 66 static __inline u_int 67 in_cksum_hdr(const struct ip *ip) 68 { 69 __uint32_t sum; 70 71 sum = asm_ones32((const void *)ip, 5); /* 5x4 = 20 bytes */ 72 sum = (sum >> 16) + (sum & 0xFFFF); 73 if (sum > 0xFFFF) 74 ++sum; 75 return(~sum & 0xFFFF); 76 } 77 78 #endif 79 80 static __inline u_short 81 in_addword(u_short sum, u_short b) 82 { 83 /* __volatile is necessary because the condition codes are used. */ 84 __asm __volatile ("addw %1, %0; adcw $0,%0" : "+r" (sum) : "r" (b)); 85 86 return (sum); 87 } 88 89 static __inline u_short 90 in_pseudo(u_int sum, u_int b, u_int c) 91 { 92 /* __volatile is necessary because the condition codes are used. */ 93 __asm __volatile ("addl %1,%0; adcl %2,%0; adcl $0,%0" 94 : "+r" (sum) 95 : "g" (b), "g" (c)); 96 sum = (sum & 0xffff) + (sum >> 16); 97 if (sum > 0xffff) 98 sum -= 0xffff; 99 return (sum); 100 } 101 102 #endif /* _MACHINE_IN_CKSUM_H_ */ 103