The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]

FreeBSD/Linux Kernel Cross Reference
sys/i386/include/in_cksum.h

Version: -  FREEBSD  -  FREEBSD-12-STABLE  -  FREEBSD-12-0  -  FREEBSD-11-STABLE  -  FREEBSD-11-2  -  FREEBSD-11-1  -  FREEBSD-11-0  -  FREEBSD-10-STABLE  -  FREEBSD-10-4  -  FREEBSD-10-3  -  FREEBSD-10-2  -  FREEBSD-10-1  -  FREEBSD-10-0  -  FREEBSD-9-STABLE  -  FREEBSD-9-3  -  FREEBSD-9-2  -  FREEBSD-9-1  -  FREEBSD-9-0  -  FREEBSD-8-STABLE  -  FREEBSD-8-4  -  FREEBSD-8-3  -  FREEBSD-8-2  -  FREEBSD-8-1  -  FREEBSD-8-0  -  FREEBSD-7-STABLE  -  FREEBSD-7-4  -  FREEBSD-7-3  -  FREEBSD-7-2  -  FREEBSD-7-1  -  FREEBSD-7-0  -  FREEBSD-6-STABLE  -  FREEBSD-6-4  -  FREEBSD-6-3  -  FREEBSD-6-2  -  FREEBSD-6-1  -  FREEBSD-6-0  -  FREEBSD-5-STABLE  -  FREEBSD-5-5  -  FREEBSD-5-4  -  FREEBSD-5-3  -  FREEBSD-5-2  -  FREEBSD-5-1  -  FREEBSD-5-0  -  FREEBSD-4-STABLE  -  FREEBSD-3-STABLE  -  FREEBSD22  -  linux-2.6  -  linux-2.4.22  -  MK83  -  MK84  -  PLAN9  -  DFBSD  -  NETBSD  -  NETBSD5  -  NETBSD4  -  NETBSD3  -  NETBSD20  -  OPENBSD  -  xnu-517  -  xnu-792  -  xnu-792.6.70  -  xnu-1228  -  xnu-1456.1.26  -  xnu-1699.24.8  -  xnu-2050.18.24  -  OPENSOLARIS  -  minix-3-1-1 
SearchContext: -  none  -  3  -  10 

    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: releng/5.0/sys/i386/include/in_cksum.h 98648 2002-06-22 22:35:53Z jdp $
   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 /* __volatile is necessary here because the condition codes are used. */
   63 #define ADD(n)  __asm __volatile ("addl %1, %0" : "+r" (sum) : \
   64     "g" (((const u_int32_t *)ip)[n / 4]))
   65 #define ADDC(n) __asm __volatile ("adcl %1, %0" : "+r" (sum) : \
   66     "g" (((const u_int32_t *)ip)[n / 4]))
   67 #define MOP     __asm __volatile ("adcl $0, %0" : "+r" (sum))
   68 
   69         ADD(0);
   70         ADDC(4);
   71         ADDC(8);
   72         ADDC(12);
   73         ADDC(16);
   74         MOP;
   75 #undef ADD
   76 #undef ADDC
   77 #undef MOP
   78         sum = (sum & 0xffff) + (sum >> 16);
   79         if (sum > 0xffff)
   80                 sum -= 0xffff;
   81 
   82         return ~sum & 0xffff;
   83 }
   84 
   85 static __inline void
   86 in_cksum_update(struct ip *ip)
   87 {
   88         int __tmpsum;
   89         __tmpsum = (int)ntohs(ip->ip_sum) + 256;
   90         ip->ip_sum = htons(__tmpsum + (__tmpsum >> 16));
   91 }
   92 
   93 static __inline u_short
   94 in_addword(u_short sum, u_short b)
   95 {
   96         /* __volatile is necessary because the condition codes are used. */
   97         __asm __volatile ("addw %1, %0" : "+r" (sum) : "r" (b));
   98         __asm __volatile ("adcw $0, %0" : "+r" (sum));
   99 
  100         return (sum);
  101 }
  102 
  103 static __inline u_short
  104 in_pseudo(u_int sum, u_int b, u_int c)
  105 {
  106         /* __volatile is necessary because the condition codes are used. */
  107         __asm __volatile ("addl %1, %0" : "+r" (sum) : "g" (b));
  108         __asm __volatile ("adcl %1, %0" : "+r" (sum) : "g" (c));
  109         __asm __volatile ("adcl $0, %0" : "+r" (sum));
  110 
  111         sum = (sum & 0xffff) + (sum >> 16);
  112         if (sum > 0xffff)
  113                 sum -= 0xffff;
  114         return (sum);
  115 }
  116 
  117 #else
  118 u_int in_cksum_hdr(const struct ip *);
  119 #define in_cksum_update(ip) \
  120         do { \
  121                 int __tmpsum; \
  122                 __tmpsum = (int)ntohs(ip->ip_sum) + 256; \
  123                 ip->ip_sum = htons(__tmpsum + (__tmpsum >> 16)); \
  124         } while(0)
  125 
  126 #endif
  127 
  128 #ifdef _KERNEL
  129 u_short in_cksum_skip(struct mbuf *m, int len, int skip); 
  130 #endif /* _KERNEL */
  131 
  132 #endif /* _MACHINE_IN_CKSUM_H_ */

Cache object: 1c1704c186e3b20b7d447221899ad1f4


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]


This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.