/* This is from the BIND 4.9.4 release, modified to compile by itself */

/* 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 "setup.h"

#ifndef HAVE_INET_PTON

#ifdef HAVE_SYS_PARAM_H
#include <sys/param.h>
#endif
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#ifdef HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif
#ifdef HAVE_ARPA_INET_H
#include <arpa/inet.h>
#endif
#include <string.h>
#include <errno.h>

#include "inet_pton.h"

#define IN6ADDRSZ       16
#define INADDRSZ         4
#define INT16SZ          2

#ifdef WIN32
#define EAFNOSUPPORT    WSAEAFNOSUPPORT
#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, unsigned char *dst );
#ifdef ENABLE_IPV6
static int      inet_pton6( const char *src, unsigned 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
Curl_inet_pton( int af, const char *src, void *dst ) {
	switch ( af ) {
	case AF_INET:
		return ( inet_pton4( src, dst ) );
#ifdef ENABLE_IPV6
#ifndef AF_INET6
#define AF_INET6        AF_MAX + 1        /* just to let this compile */
#endif
	case AF_INET6:
		return ( inet_pton6( src, dst ) );
#endif
	default:
		errno = EAFNOSUPPORT;
		return ( -1 );
	}
	/* NOTREACHED */
}

/* int
 * inet_pton4(src, dst)
 *      like inet_aton() but without all the hexadecimal and shorthand.
 * return:
 *      1 if `src' is a valid dotted quad, else 0.
 * notice:
 *      does not touch `dst' unless it's returning 1.
 * author:
 *      Paul Vixie, 1996.
 */
static int
inet_pton4( const char *src, unsigned char *dst ) {
	static const char digits[] = "0123456789";
	int saw_digit, octets, ch;
	unsigned char tmp[INADDRSZ], *tp;

	saw_digit = 0;
	octets = 0;
	tp = tmp;
	*tp = 0;
	while ( ( ch = *src++ ) != '\0' ) {
		const char *pch;

		if ( ( pch = strchr( digits, ch ) ) != NULL ) {
			u_int new = *tp * 10 + ( pch - digits );

			if ( new > 255 ) {
				return ( 0 );
			}
			*tp = new;
			if ( !saw_digit ) {
				if ( ++octets > 4 ) {
					return ( 0 );
				}
				saw_digit = 1;
			}
		} else if ( ch == '.' && saw_digit ) {
			if ( octets == 4 ) {
				return ( 0 );
			}
			*++tp = 0;
			saw_digit = 0;
		} else {
			return ( 0 );
		}
	}
	if ( octets < 4 ) {
		return ( 0 );
	}
	/* bcopy(tmp, dst, INADDRSZ); */
	memcpy( dst, tmp, INADDRSZ );
	return ( 1 );
}

#ifdef 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, unsigned char *dst ) {
	static const char xdigits_l[] = "0123456789abcdef",
					  xdigits_u[] = "0123456789ABCDEF";
	unsigned 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;
			}
			if ( tp + INT16SZ > endp ) {
				return ( 0 );
			}
			*tp++ = ( unsigned char )( val >> 8 ) & 0xff;
			*tp++ = (unsigned char) val & 0xff;
			saw_xdigit = 0;
			val = 0;
			continue;
		}
		if ( ch == '.' && ( ( tp + INADDRSZ ) <= endp ) &&
			 inet_pton4( curtok, tp ) > 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++ = ( unsigned char )( val >> 8 ) & 0xff;
		*tp++ = (unsigned 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;

		for ( i = 1; i <= n; i++ ) {
			endp[-i] = colonp[n - i];
			colonp[n - i] = 0;
		}
		tp = endp;
	}
	if ( tp != endp ) {
		return ( 0 );
	}
	/* bcopy(tmp, dst, IN6ADDRSZ); */
	memcpy( dst, tmp, IN6ADDRSZ );
	return ( 1 );
}
#endif /* ENABLE_IPV6 */

#endif /* HAVE_INET_PTON */