/*

 * Portions Copyright (C) Internet Systems Consortium, Inc. ("ISC")

 *

 * This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, you can obtain one at https://mozilla.org/MPL/2.0/.

 *

 * See the COPYRIGHT file distributed with this work for additional

 * information regarding copyright ownership.

 */

/*

 * 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. 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.

 */

/*

 * Portions Copyright (c) 1993 by Digital Equipment Corporation.

 *

 * 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, and that

 * the name of Digital Equipment Corporation not be used in advertising or

 * publicity pertaining to distribution of the document or software without

 * specific, written prior permission.

 *

 * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL

 * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES

 * OF MERCHANTABILITY AND FITNESS.   IN NO EVENT SHALL DIGITAL EQUIPMENT

 * CORPORATION 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.

 */

/*! \file lwinetaton.c

 */

#if defined(LIBC_SCCS) && !defined(lint)

static char sccsid[] = "@(#)inet_addr.c	8.1 (Berkeley) 6/17/93";

#endif /* LIBC_SCCS and not lint */

#include <config.h>

#include <ctype.h>

#include <inttypes.h>

#include <stddef.h>

#include <lwres/net.h>

#include "assert_p.h"

/*!

 * 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.

 */

int

lwres_net_aton(const char *cp, struct in_addr *addr) {

	uint32_t val;

	int base;

	ptrdiff_t n;

	unsigned char c;

	uint8_t parts[4];

	uint8_t *pp = parts;

	int digit;

	REQUIRE(cp != NULL);

	c = *cp;

	for (;;) {

		/*

		 * Collect number up to ``.''.

		 * Values are specified as for C:

		 * 0x=hex, 0=octal, isdigit=decimal.

		 */

		if (!isdigit(c & 0xff))

			return (0);

		val = 0;

		base = 10;

		digit = 0;

		if (c == '0') {

			c = *++cp;

			if (c == 'x' || c == 'X') {

				base = 16;

				c = *++cp;

			} else {

				base = 8;

				digit = 1;

			}

		}

		for (;;) {

			/*

			 * isascii() is valid for all integer values, and

			 * when it is true, c is known to be in scope

			 * for isdigit().  No cast necessary.  Similar

			 * comment applies for later ctype uses.

			 */

			if (isascii(c) && isdigit(c)) {

				if (base == 8 && (c == '8' || c == '9'))

					return (0);

				val = (val * base) + (c - '0');

				c = *++cp;

				digit = 1;

			} else if (base == 16 && isascii(c) && isxdigit(c)) {

				val = (val << 4) |

					(c + 10 - (islower(c) ? 'a' : 'A'));

				c = *++cp;

				digit = 1;

			} 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 || val > 0xffU)

				return (0);

			*pp++ = (uint8_t)val;

			c = *++cp;

		} else

			break;

	}

	/*

	 * Check for trailing characters.

	 */

	if (c != '\0' && (!isascii(c) || !isspace(c)))

		return (0);

	/*

	 * Did we get a valid digit?

	 */

	if (!digit)

		return (0);

	/*

	 * Concoct the address according to

	 * the number of parts specified.

	 */

	n = pp - parts + 1;

	switch (n) {

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

		break;

	case 2:				/* a.b -- 8.24 bits */

		if (val > 0xffffffU)

			return (0);

#define ulshift(x, n) ((unsigned int)(x) << (n))

		val |= ulshift(parts[0], 24);

		break;

	case 3:				/* a.b.c -- 8.8.16 bits */

		if (val > 0xffffU)

			return (0);

		val |= ulshift(parts[0], 24) | ulshift(parts[1], 16);

		break;

	case 4:				/* a.b.c.d -- 8.8.8.8 bits */

		if (val > 0xffU)

			return (0);

		val |= ulshift(parts[0], 24) | ulshift(parts[1], 16) |

			ulshift(parts[2], 8);

		break;

	}

	if (addr != NULL)

		addr->s_addr = htonl(val);

	return (1);

}