/*	Id: inet_pton.c,v 1.5 2001/04/13 15:24:35 lukem Exp 	*/

/*	$NetBSD: inet_pton.c,v 1.16 2000/02/07 18:51:02 itojun Exp $	*/

/* 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.

 */

#include <net-snmp/net-snmp-config.h>

#include <ctype.h>

#if HAVE_ARPA_NAMESER_H

#include <arpa/nameser.h>

#endif

#include <errno.h>

#include <stdio.h>

#if HAVE_STRING_H

#include <string.h>

#else

#include <strings.h>

#endif

#include <net-snmp/types.h>

#include "inet_pton.h"

#ifndef EAFNOSUPPORT

#define EAFNOSUPPORT            WSAEAFNOSUPPORT

#endif

#ifndef IN6ADDRSZ

#define	IN6ADDRSZ	16

#endif

#ifndef INT16SZ

#define	INT16SZ		2

#endif

#ifndef INADDRSZ

#define	INADDRSZ	4

#endif

/*

 * WARNING: Don't even consider trying to compile this on a system where

 * sizeof(int) < 4.  sizeof(int) > 4 is fine; all the world's not a VAX.

 */

static int	inet_pton4(const char *src, u_char *dst, int pton);

#ifdef NETSNMP_ENABLE_IPV6

static int	inet_pton6(const char *src, u_char *dst);

#endif

/* int

 * inet_pton(af, src, dst)

 *	convert from presentation format (which usually means ASCII printable)

 *	to network format (which is usually some kind of binary format).

 * return:

 *	1 if the address was valid for the specified address family

 *	0 if the address wasn't valid (`dst' is untouched in this case)

 *	-1 if some other error occurred (`dst' is untouched in this case, too)

 * author:

 *	Paul Vixie, 1996.

 */

int

netsnmp_inet_pton(int af, const char *src, void *dst)

{

	switch (af) {

	case AF_INET:

		return (inet_pton4(src, dst, 1));

#ifdef NETSNMP_ENABLE_IPV6

	case AF_INET6:

		return (inet_pton6(src, dst));

#endif

	default:

		errno = EAFNOSUPPORT;

		return (-1);

	}

	/* NOTREACHED */

}

/* int

 * inet_pton4(src, dst, pton)

 *	when last arg is 0: inet_aton(). with hexadecimal, octal and shorthand.

 *	when last arg is 1: inet_pton(). decimal dotted-quad only.

 * return:

 *	1 if `src' is a valid input, else 0.

 * notice:

 *	does not touch `dst' unless it's returning 1.

 * author:

 *	Paul Vixie, 1996.

 */

static int

inet_pton4(const char *src, u_char *dst, int pton)

{

	u_int val;

	u_int digit;

	int base, n;

	unsigned char c;

	u_int parts[4];

	register u_int *pp = parts;

	c = *src;

	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 = *++src;

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

				base = 16, c = *++src;

			else if (isdigit(c) && c != '9')

				base = 8;

		}

		/* inet_pton() takes decimal only */

		if (pton && base != 10)

			return (0);

		for (;;) {

			if (isdigit(c)) {

				digit = c - '0';

				if ((int)digit >= base)

					break;

				val = (val * base) + digit;

				c = *++src;

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

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

				if (digit >= 16)

					break;

				val = (val << 4) | digit;

				c = *++src;

			} 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)

			 *	a	(with a treated as 32 bits)

			 */

			if (pp >= parts + 3)

				return (0);

			*pp++ = val;

			c = *++src;

		} else

			break;

	}

	/*

	 * Check for trailing characters.

	 */

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

		return (0);

	/*

	 * Concoct the address according to

	 * the number of parts specified.

	 */

	n = pp - parts + 1;

	/* inet_pton() takes dotted-quad only.  it does not take shorthand. */

	if (pton && n != 4)

		return (0);

	switch (n) {

	case 0:

		return (0);		/* initial nondigit */

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

		break;

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

		if (parts[0] > 0xff || val > 0xffffff)

			return (0);

		val |= parts[0] << 24;

		break;

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

		if ((parts[0] | parts[1]) > 0xff || val > 0xffff)

			return (0);

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

		break;

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

		if ((parts[0] | parts[1] | parts[2] | val) > 0xff)

			return (0);

		val |= (parts[0] << 24) | (parts[1] << 16) | (parts[2] << 8);

		break;

	}

	if (dst) {

		val = htonl(val);

		memcpy(dst, &val, INADDRSZ);

	}

	return (1);

}

#ifdef NETSNMP_ENABLE_IPV6

/* int

 * inet_pton6(src, dst)

 *	convert presentation level address to network order binary form.

 * return:

 *	1 if `src' is a valid [RFC1884 2.2] address, else 0.

 * notice:

 *	(1) does not touch `dst' unless it's returning 1.

 *	(2) :: in a full address is silently ignored.

 * credit:

 *	inspired by Mark Andrews.

 * author:

 *	Paul Vixie, 1996.

 */

static int

inet_pton6(const char *src, u_char *dst)

{

	static const char xdigits_l[] = "0123456789abcdef",

			  xdigits_u[] = "0123456789ABCDEF";

	u_char tmp[IN6ADDRSZ], *tp, *endp, *colonp;

	const char *xdigits, *curtok;

	int ch, saw_xdigit;

	u_int val;

	memset((tp = tmp), '\0', IN6ADDRSZ);

	endp = tp + IN6ADDRSZ;

	colonp = NULL;

	/* Leading :: requires some special handling. */

	if (*src == ':')

		if (*++src != ':')

			return (0);

	curtok = src;

	saw_xdigit = 0;

	val = 0;

	while ((ch = *src++) != '\0') {

		const char *pch;

		if ((pch = strchr((xdigits = xdigits_l), ch)) == NULL)

			pch = strchr((xdigits = xdigits_u), ch);

		if (pch != NULL) {

			val <<= 4;

			val |= (pch - xdigits);

			if (val > 0xffff)

				return (0);

			saw_xdigit = 1;

			continue;

		}

		if (ch == ':') {

			curtok = src;

			if (!saw_xdigit) {

				if (colonp)

					return (0);

				colonp = tp;

				continue;

			} else if (*src == '\0')

				return (0);

			if (tp + INT16SZ > endp)

				return (0);

			*tp++ = (u_char) (val >> 8) & 0xff;

			*tp++ = (u_char) val & 0xff;

			saw_xdigit = 0;

			val = 0;

			continue;

		}

		if (ch == '.' && ((tp + INADDRSZ) <= endp) &&

		    inet_pton4(curtok, tp, 1) > 0) {

			tp += INADDRSZ;

			saw_xdigit = 0;

			break;	/* '\0' was seen by inet_pton4(). */

		}

		return (0);

	}

	if (saw_xdigit) {

		if (tp + INT16SZ > endp)

			return (0);

		*tp++ = (u_char) (val >> 8) & 0xff;

		*tp++ = (u_char) val & 0xff;

	}

	if (colonp != NULL) {

		/*

		 * Since some memmove()'s erroneously fail to handle

		 * overlapping regions, we'll do the shift by hand.

		 */

		const int n = tp - colonp;

		int i;

		if (tp == endp)

			return (0);

		for (i = 1; i <= n; i++) {

			endp[- i] = colonp[n - i];

			colonp[n - i] = 0;

		}

		tp = endp;

	}

	if (tp != endp)

		return (0);

	memcpy(dst, tmp, IN6ADDRSZ);

	return (1);

}

#endif