mirror of
https://git.FreeBSD.org/src.git
synced 2024-12-23 11:18:54 +00:00
60 lines
2.3 KiB
C
60 lines
2.3 KiB
C
/*-
|
|
* Copyright (c) 1991, 1993
|
|
* The Regents of the University of California. All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
* 3. All advertising materials mentioning features or use of this software
|
|
* must display the following acknowledgement:
|
|
* This product includes software developed by the University of
|
|
* California, Berkeley and its contributors.
|
|
* 4. Neither the name of the University nor the names of its contributors
|
|
* may be used to endorse or promote products derived from this software
|
|
* without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*
|
|
* @(#)lfs_cksum.c 8.1 (Berkeley) 6/11/93
|
|
* $Id$
|
|
*/
|
|
|
|
#include <sys/types.h>
|
|
|
|
/*
|
|
* Simple, general purpose, fast checksum. Data must be short-aligned.
|
|
* Returns a u_long in case we ever want to do something more rigorous.
|
|
*
|
|
* XXX
|
|
* Use the TCP/IP checksum instead.
|
|
*/
|
|
u_long
|
|
cksum(str, len)
|
|
register void *str;
|
|
register size_t len;
|
|
{
|
|
register u_long sum;
|
|
|
|
len &= ~(sizeof(u_short) - 1);
|
|
for (sum = 0; len; len -= sizeof(u_short)) {
|
|
sum ^= *(u_short *)str;
|
|
++(u_short *)str;
|
|
}
|
|
return (sum);
|
|
}
|