f36cfd49ad
license, per letter dated July 22, 1999 and email from Peter Wemm, Alan Cox and Robert Watson. Approved by: core, peter, alc, rwatson
133 lines
4.1 KiB
C
133 lines
4.1 KiB
C
/*-
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* Copyright (c) 1990 The Regents of the University of California.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* from tahoe: in_cksum.c 1.2 86/01/05
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* from: @(#)in_cksum.c 1.3 (Berkeley) 1/19/91
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* from: Id: in_cksum.c,v 1.8 1995/12/03 18:35:19 bde Exp
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* $FreeBSD$
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*/
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#ifndef _MACHINE_IN_CKSUM_H_
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#define _MACHINE_IN_CKSUM_H_ 1
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/*
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* MP safe (alfred)
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*/
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#include <sys/cdefs.h>
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#define in_cksum(m, len) in_cksum_skip(m, len, 0)
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/*
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* It it useful to have an Internet checksum routine which is inlineable
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* and optimized specifically for the task of computing IP header checksums
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* in the normal case (where there are no options and the header length is
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* therefore always exactly five 32-bit words.
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*/
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#if defined(__GNUC__) && !defined(__INTEL_COMPILER)
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static __inline u_int
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in_cksum_hdr(const struct ip *ip)
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{
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register u_int sum = 0;
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/* __volatile is necessary here because the condition codes are used. */
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#define ADD(n) __asm __volatile ("addl %1, %0" : "+r" (sum) : \
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"g" (((const u_int32_t *)ip)[n / 4]))
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#define ADDC(n) __asm __volatile ("adcl %1, %0" : "+r" (sum) : \
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"g" (((const u_int32_t *)ip)[n / 4]))
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#define MOP __asm __volatile ("adcl $0, %0" : "+r" (sum))
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ADD(0);
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ADDC(4);
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ADDC(8);
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ADDC(12);
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ADDC(16);
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MOP;
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#undef ADD
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#undef ADDC
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#undef MOP
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sum = (sum & 0xffff) + (sum >> 16);
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if (sum > 0xffff)
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sum -= 0xffff;
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return ~sum & 0xffff;
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}
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static __inline void
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in_cksum_update(struct ip *ip)
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{
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int __tmpsum;
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__tmpsum = (int)ntohs(ip->ip_sum) + 256;
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ip->ip_sum = htons(__tmpsum + (__tmpsum >> 16));
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}
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static __inline u_short
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in_addword(u_short sum, u_short b)
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{
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/* __volatile is necessary because the condition codes are used. */
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__asm __volatile ("addw %1, %0" : "+r" (sum) : "r" (b));
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__asm __volatile ("adcw $0, %0" : "+r" (sum));
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return (sum);
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}
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static __inline u_short
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in_pseudo(u_int sum, u_int b, u_int c)
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{
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/* __volatile is necessary because the condition codes are used. */
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__asm __volatile ("addl %1, %0" : "+r" (sum) : "g" (b));
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__asm __volatile ("adcl %1, %0" : "+r" (sum) : "g" (c));
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__asm __volatile ("adcl $0, %0" : "+r" (sum));
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sum = (sum & 0xffff) + (sum >> 16);
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if (sum > 0xffff)
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sum -= 0xffff;
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return (sum);
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}
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#else
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#define in_cksum_update(ip) \
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do { \
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int __tmpsum; \
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__tmpsum = (int)ntohs(ip->ip_sum) + 256; \
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ip->ip_sum = htons(__tmpsum + (__tmpsum >> 16)); \
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} while(0)
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#endif
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#ifdef _KERNEL
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#if !defined(__GNUC__) || defined(__INTEL_COMPILER)
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u_int in_cksum_hdr(const struct ip *ip);
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u_short in_addword(u_short sum, u_short b);
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u_short in_pseudo(u_int sum, u_int b, u_int c);
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#endif
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u_short in_cksum_skip(struct mbuf *m, int len, int skip);
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#endif /* _KERNEL */
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#endif /* _MACHINE_IN_CKSUM_H_ */
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