GCC Code Coverage Report
Directory: ./ Exec Total Coverage
File: usr.sbin/dvmrpd/in_cksum.c Lines: 0 18 0.0 %
Date: 2017-11-13 Branches: 0 10 0.0 %

Line Branch Exec Source
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/*	$OpenBSD: in_cksum.c,v 1.4 2014/07/20 20:27:19 tobias Exp $ */
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/*	$NetBSD: in_cksum.c,v 1.3 1995/04/22 13:53:48 cgd Exp $	*/
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/*
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 * Copyright (c) 1992 Regents of the University of California.
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 * All rights reserved.
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 *
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 * This software was developed by the Computer Systems Engineering group
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 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
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 * contributed to Berkeley.
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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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 * 3. 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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 * @(#) Header: in_cksum.c,v 1.1 92/09/11 01:15:55 leres Exp  (LBL)
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 */
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#include <sys/types.h>
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#include "dvmrpd.h"
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#include "log.h"
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/*
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 * Checksum routine for Internet Protocol family headers.
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 * This routine is very heavily used in the network
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 * code and should be modified for each CPU to be as fast as possible.
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 * In particular, it should not be this one.
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 */
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u_int16_t
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in_cksum(void *p, size_t l)
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{
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	unsigned int sum = 0;
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	int len;
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	u_char *cp = p;
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	/* ensure that < 2^16 bytes being summed */
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	if (l >= (1 << 16))
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		fatalx("in_cksum: packet too big");
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	len = (int)l;
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	if (((long)cp & 1) == 0) {
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		while (len > 1) {
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			sum += htons(*(u_short *)cp);
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			cp += 2;
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			len -= 2;
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		}
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	} else {
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		while (len > 1) {
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			sum += *cp++ << 8;
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			sum += *cp++;
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			len -= 2;
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		}
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	}
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	if (len == 1)
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		sum += *cp << 8;
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	sum = (sum >> 16) + (sum & 0xffff); /* add in accumulated carries */
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	sum += sum >> 16;		/* add potential last carry */
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	sum = ntohs(sum);
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	return (0xffff & ~sum);
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}