inetaddr.c

uC/IP源代码 2003-08-16[摘][码] 该软件是本人在ucos_ii基础上加上网络功能

/*****************************************************************************
* InetAddr.c - 
*
* Copyright (c) 1983, 1990, 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.
*
* portions Copyright (c) 2001 by Cognizant Pty Ltd.
*
* The authors hereby grant permission to use, copy, modify, distribute,
* and license this software and its documentation for any purpose, provided
* that existing copyright notices are retained in all copies and that this
* notice and the following disclaimer are included verbatim in any 
* distributions. No written agreement, license, or royalty fee is required
* for any of the authorized uses.
*
* THIS SOFTWARE IS PROVIDED BY THE 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 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.
*
******************************************************************************
* REVISION HISTORY (please don't use tabs!)
*
*(yyyy-mm-dd)
* 2001-05-12 Robert Dickenson <[e-mail]>, Cognizant Pty Ltd.
*            Minor modifications to original file from NetBSD.
*
******************************************************************************
*/
#include "includes.h"
#include "ether.h"

/*
 * Ascii internet address interpretation routine.
 * The value returned is in network order.
 */

/*  */


/* 
 * Check whether "cp" is a valid ascii representation
 * of an Internet address and convert to a binary address.
 * Returns 1 if the address is valid, 0 if not.
 * This replaces inet_addr, the return value from which
 * cannot distinguish between failure and a local broadcast address.
 */
/*  */
/* inet_aton */
int inet_aton(register const char *cp, struct in_addr *addr)
{
	register u_long val;
	register int base, n;
	register char c;
	u_int parts[4];
	register u_int *pp = parts;

	c = *cp;
	for (;;) {
		/*
		 * Collect number up to ``.''.
		 * Values are specified as for C:
		 * 0x=hex, 0=octal, isdigit=decimal.
		 */
		if (!isdigit(c))
			return (0);
		val = 0; base = 10;
		if (c == '0') {
			c = *++cp;
			if (c == 'x' || c == 'X')
				base = 16, c = *++cp;
			else
				base = 8;
		}
		for (;;) {
			if (isascii(c) && isdigit(c)) {
				val = (val * base) + (c - '0');
				c = *++cp;
			} else if (base == 16 && isascii(c) && isxdigit(c)) {
				val = (val << 4) |
					(c + 10 - (islower(c) ? 'a' : 'A'));
				c = *++cp;
			} else
			break;
		}
		if (c == '.') {
			/*
			 * Internet format:
			 *	a.b.c.d
			 *	a.b.c	(with c treated as 16 bits)
			 *	a.b	(with b treated as 24 bits)
			 */
			if (pp >= parts + 3)
				return (0);
			*pp++ = val;
			c = *++cp;
		} else
			break;
	}
	/*
	 * Check for trailing characters.
	 */
	if (c != '\0' && (!isascii(c) || !isspace(c)))
		return (0);
	/*
	 * Concoct the address according to
	 * the number of parts specified.
	 */
	n = pp - parts + 1;
	switch (n) {

	case 0:
		return (0);		/* initial nondigit */

	case 1:				/* a -- 32 bits */
		break;

	case 2:				/* a.b -- 8.24 bits */
		if (val > 0xffffff)
			return (0);
		val |= parts[0] << 24;
		break;

	case 3:				/* a.b.c -- 8.8.16 bits */
		if (val > 0xffff)
			return (0);
		val |= (parts[0] << 24) | (parts[1] << 16);
		break;

	case 4:				/* a.b.c.d -- 8.8.8.8 bits */
		if (val > 0xff)
			return (0);
		val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8);
		break;
	}
	if (addr)
		addr->s_addr = htonl(val);
	return (1);
}
/* inet_addr */
u_long inet_addr(register const char *cp)
{
	struct in_addr val;

	if (inet_aton(cp, &val))
		return (val.s_addr);
	return (0);
}