sum-bsd.c revision 3f54fd611f536639ec30dd53c48e5ec1897cc7d9
/***********************************************************************
* *
* This software is part of the ast package *
* Copyright (c) 1996-2011 AT&T Intellectual Property *
* and is licensed under the *
* Eclipse Public License, Version 1.0 *
* by AT&T Intellectual Property *
* *
* A copy of the License is available at *
* http://www.eclipse.org/org/documents/epl-v10.html *
* (with md5 checksum b35adb5213ca9657e911e9befb180842) *
* *
* Information and Software Systems Research *
* AT&T Research *
* Florham Park NJ *
* *
* Glenn Fowler <gsf@research.att.com> *
* *
***********************************************************************/
#pragma prototyped
/*
* bsd
*/
#define bsd_description \
"The BSD checksum."
#define bsd_options 0
#define bsd_match "bsd|ucb"
#define bsd_open long_open
#define bsd_init long_init
#define bsd_done short_done
#define bsd_print long_print
#define bsd_data long_data
#define bsd_scale 1024
static int
bsd_block(register Sum_t* p, const void* s, size_t n)
{
register uint32_t c = ((Integral_t*)p)->sum;
register unsigned char* b = (unsigned char*)s;
register unsigned char* e = b + n;
while (b < e)
c = ((c >> 1) + *b++ + ((c & 01) ? 0x8000 : 0)) & 0xffff;
((Integral_t*)p)->sum = c;
return 0;
}