C++程序  |  126行  |  4.02 KB

/*
 * Copyright (c) 1996 by Internet Software Consortium.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
 * SOFTWARE.
 */

/*
 * Portions copyright (c) 1999, 2000
 * Intel Corporation.
 * 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 Intel Corporation and
 *    its contributors.
 * 
 * 4. Neither the name of Intel Corporation or its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY INTEL CORPORATION 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 INTEL CORPORATION 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.
 * 
 */

#if defined(LIBC_SCCS) && !defined(lint)
static const char orig_rcsid[] = "From Id: inet_neta.c,v 8.2 1996/08/08 06:54:44 vixie Exp";
static const char rcsid[] = "$Id: inet_neta.c,v 1.1.1.1 2003/11/19 01:51:29 kyu3 Exp $";
#endif

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>

#include <errno.h>
#include <stdio.h>
#include <string.h>

#ifdef SPRINTF_CHAR
# define SPRINTF(x) strlen(sprintf/**/x)
#else
# define SPRINTF(x) ((size_t)sprintf x)
#endif

/*
 * char *
 * inet_neta(src, dst, size)
 *	format a u_long network number into presentation format.
 * return:
 *	pointer to dst, or NULL if an error occurred (check errno).
 * note:
 *	format of ``src'' is as for inet_network().
 * author:
 *	Paul Vixie (ISC), July 1996
 */
char *
inet_neta(
	u_long src,
	char *dst,
	size_t size
	)
{
	char *odst = dst;
	char *tp;

	while (src & 0xffffffff) {
		u_char b = (u_char)((src & 0xff000000) >> 24);

		src <<= 8;
		if (b) {
			if (size < sizeof "255.")
				goto emsgsize;
			tp = dst;
			dst += SPRINTF((dst, "%u", b));
			if (src != 0L) {
				*dst++ = '.';
				*dst = '\0';
			}
			size -= (size_t)(dst - tp);
		}
	}
	if (dst == odst) {
		if (size < sizeof "0.0.0.0")
			goto emsgsize;
		strcpy(dst, "0.0.0.0");
	}
	return (odst);

 emsgsize:
	errno = EMSGSIZE;
	return (NULL);
}