[openssh.git] / openbsd-compat / inet_ntop.c

/*	$OpenBSD: inet_ntop.c,v 1.5 2002/08/23 16:27:31 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.
 */

/* OPENBSD ORIGINAL: lib/libc/net/inet_ntop.c */

#include "includes.h"

#ifndef HAVE_INET_NTOP

#if defined(LIBC_SCCS) && !defined(lint)
#if 0
static char rcsid[] = "$From: inet_ntop.c,v 8.7 1996/08/05 08:41:18 vixie Exp $";
#else
static char rcsid[] = "$OpenBSD: inet_ntop.c,v 1.5 2002/08/23 16:27:31 itojun Exp $";
#endif
#endif /* LIBC_SCCS and not lint */

#include <sys/param.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <arpa/nameser.h>
#include <string.h>
#include <errno.h>
#include <stdio.h>

#ifndef IN6ADDRSZ
#define IN6ADDRSZ   16   /* IPv6 T_AAAA */                 
#endif

#ifndef INT16SZ
#define INT16SZ     2    /* for systems without 16-bit ints */
#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 const char *inet_ntop4(const u_char *src, char *dst, size_t size);
static const char *inet_ntop6(const u_char *src, char *dst, size_t size);

/* char *
 * inet_ntop(af, src, dst, size)
 *	convert a network format address to presentation format.
 * return:
 *	pointer to presentation format address (`dst'), or NULL (see errno).
 * author:
 *	Paul Vixie, 1996.
 */
const char *
inet_ntop(af, src, dst, size)
	int af;
	const void *src;
	char *dst;
	size_t size;
{
	switch (af) {
	case AF_INET:
		return (inet_ntop4(src, dst, size));
	case AF_INET6:
		return (inet_ntop6(src, dst, size));
	default:
		errno = EAFNOSUPPORT;
		return (NULL);
	}
	/* NOTREACHED */
}

/* const char *
 * inet_ntop4(src, dst, size)
 *	format an IPv4 address, more or less like inet_ntoa()
 * return:
 *	`dst' (as a const)
 * notes:
 *	(1) uses no statics
 *	(2) takes a u_char* not an in_addr as input
 * author:
 *	Paul Vixie, 1996.
 */
static const char *
inet_ntop4(src, dst, size)
	const u_char *src;
	char *dst;
	size_t size;
{
	static const char fmt[] = "%u.%u.%u.%u";
	char tmp[sizeof "255.255.255.255"];
	int l;

	l = snprintf(tmp, size, fmt, src[0], src[1], src[2], src[3]);
	if (l <= 0 || l >= size) {
		errno = ENOSPC;
		return (NULL);
	}
	strlcpy(dst, tmp, size);
	return (dst);
}

/* const char *
 * inet_ntop6(src, dst, size)
 *	convert IPv6 binary address into presentation (printable) format
 * author:
 *	Paul Vixie, 1996.
 */
static const char *
inet_ntop6(src, dst, size)
	const u_char *src;
	char *dst;
	size_t size;
{
	/*
	 * Note that int32_t and int16_t need only be "at least" large enough
	 * to contain a value of the specified size.  On some systems, like
	 * Crays, there is no such thing as an integer variable with 16 bits.
	 * Keep this in mind if you think this function should have been coded
	 * to use pointer overlays.  All the world's not a VAX.
	 */
	char tmp[sizeof "ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255"];
	char *tp, *ep;
	struct { int base, len; } best, cur;
	u_int words[IN6ADDRSZ / INT16SZ];
	int i;
	int advance;

	/*
	 * Preprocess:
	 *	Copy the input (bytewise) array into a wordwise array.
	 *	Find the longest run of 0x00's in src[] for :: shorthanding.
	 */
	memset(words, '\0', sizeof words);
	for (i = 0; i < IN6ADDRSZ; i++)
		words[i / 2] |= (src[i] << ((1 - (i % 2)) << 3));
	best.base = -1;
	cur.base = -1;
	for (i = 0; i < (IN6ADDRSZ / INT16SZ); i++) {
		if (words[i] == 0) {
			if (cur.base == -1)
				cur.base = i, cur.len = 1;
			else
				cur.len++;
		} else {
			if (cur.base != -1) {
				if (best.base == -1 || cur.len > best.len)
					best = cur;
				cur.base = -1;
			}
		}
	}
	if (cur.base != -1) {
		if (best.base == -1 || cur.len > best.len)
			best = cur;
	}
	if (best.base != -1 && best.len < 2)
		best.base = -1;

	/*
	 * Format the result.
	 */
	tp = tmp;
	ep = tmp + sizeof(tmp);
	for (i = 0; i < (IN6ADDRSZ / INT16SZ) && tp < ep; i++) {
		/* Are we inside the best run of 0x00's? */
		if (best.base != -1 && i >= best.base &&
		    i < (best.base + best.len)) {
			if (i == best.base) {
				if (tp + 1 >= ep)
					return (NULL);
				*tp++ = ':';
			}
			continue;
		}
		/* Are we following an initial run of 0x00s or any real hex? */
		if (i != 0) {
			if (tp + 1 >= ep)
				return (NULL);
			*tp++ = ':';
		}
		/* Is this address an encapsulated IPv4? */
		if (i == 6 && best.base == 0 &&
		    (best.len == 6 || (best.len == 5 && words[5] == 0xffff))) {
			if (!inet_ntop4(src+12, tp, (size_t)(ep - tp)))
				return (NULL);
			tp += strlen(tp);
			break;
		}
		advance = snprintf(tp, ep - tp, "%x", words[i]);
		if (advance <= 0 || advance >= ep - tp)
			return (NULL);
		tp += advance;
	}
	/* Was it a trailing run of 0x00's? */
	if (best.base != -1 && (best.base + best.len) == (IN6ADDRSZ / INT16SZ)) {
		if (tp + 1 >= ep)
			return (NULL);
		*tp++ = ':';
	}
	if (tp + 1 >= ep)
		return (NULL);
	*tp++ = '\0';

	/*
	 * Check for overflow, copy, and we're done.
	 */
	if ((size_t)(tp - tmp) > size) {
		errno = ENOSPC;
		return (NULL);
	}
	strlcpy(dst, tmp, size);
	return (dst);
}

#endif /* !HAVE_INET_NTOP */
Commit	Line	Data
ac8802eb	1	/* $OpenBSD: inet_ntop.c,v 1.5 2002/08/23 16:27:31 itojun Exp $ */
a704dd54	2
	3	/* Copyright (c) 1996 by Internet Software Consortium.
	4	*
	5	* Permission to use, copy, modify, and distribute this software for any
	6	* purpose with or without fee is hereby granted, provided that the above
	7	* copyright notice and this permission notice appear in all copies.
	8	*
	9	* THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
	10	* ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
	11	* OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
	12	* CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
	13	* DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
	14	* PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
	15	* ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
	16	* SOFTWARE.
	17	*/
	18
f6d4fb87	19	/* OPENBSD ORIGINAL: lib/libc/net/inet_ntop.c */
f6d4fb87	20
17962c40	21	#include "includes.h"
a704dd54	22
	23	#ifndef HAVE_INET_NTOP
	24
	25	#if defined(LIBC_SCCS) && !defined(lint)
	26	#if 0
	27	static char rcsid[] = "$From: inet_ntop.c,v 8.7 1996/08/05 08:41:18 vixie Exp $";
	28	#else
ac8802eb	29	static char rcsid[] = "$OpenBSD: inet_ntop.c,v 1.5 2002/08/23 16:27:31 itojun Exp $";
a704dd54	30	#endif
	31	#endif /* LIBC_SCCS and not lint */
	32
	33	#include <sys/param.h>
	34	#include <sys/types.h>
	35	#include <sys/socket.h>
a704dd54	36	#include <netinet/in.h>
a704dd54	37	#include <arpa/inet.h>
a704dd54	38	#include <arpa/nameser.h>
a704dd54	39	#include <string.h>
	40	#include <errno.h>
	41	#include <stdio.h>
	42
	43	#ifndef IN6ADDRSZ
	44	#define IN6ADDRSZ 16 /* IPv6 T_AAAA */
	45	#endif
	46
	47	#ifndef INT16SZ
	48	#define INT16SZ 2 /* for systems without 16-bit ints */
	49	#endif
	50
	51	/*
	52	* WARNING: Don't even consider trying to compile this on a system where
	53	* sizeof(int) < 4. sizeof(int) > 4 is fine; all the world's not a VAX.
	54	*/
	55
ac8802eb	56	static const char inet_ntop4(const u_char src, char *dst, size_t size);
ac8802eb	57	static const char inet_ntop6(const u_char src, char *dst, size_t size);
a704dd54	58
	59	/* char *
	60	* inet_ntop(af, src, dst, size)
	61	* convert a network format address to presentation format.
	62	* return:
	63	* pointer to presentation format address (`dst'), or NULL (see errno).
	64	* author:
	65	* Paul Vixie, 1996.
	66	*/
	67	const char *
	68	inet_ntop(af, src, dst, size)
	69	int af;
	70	const void *src;
	71	char *dst;
	72	size_t size;
	73	{
	74	switch (af) {
	75	case AF_INET:
	76	return (inet_ntop4(src, dst, size));
	77	case AF_INET6:
	78	return (inet_ntop6(src, dst, size));
	79	default:
	80	errno = EAFNOSUPPORT;
	81	return (NULL);
	82	}
	83	/* NOTREACHED */
	84	}
	85
	86	/* const char *
	87	* inet_ntop4(src, dst, size)
	88	* format an IPv4 address, more or less like inet_ntoa()
	89	* return:
	90	* `dst' (as a const)
	91	* notes:
	92	* (1) uses no statics
	93	* (2) takes a u_char* not an in_addr as input
	94	* author:
	95	* Paul Vixie, 1996.
	96	*/
	97	static const char *
	98	inet_ntop4(src, dst, size)
	99	const u_char *src;
	100	char *dst;
	101	size_t size;
	102	{
	103	static const char fmt[] = "%u.%u.%u.%u";
	104	char tmp[sizeof "255.255.255.255"];
ac8802eb	105	int l;
a704dd54	106
ac8802eb	107	l = snprintf(tmp, size, fmt, src[0], src[1], src[2], src[3]);
ac8802eb	108	if (l <= 0 \|\| l >= size) {
a704dd54	109	errno = ENOSPC;
	110	return (NULL);
	111	}
ac8802eb	112	strlcpy(dst, tmp, size);
a704dd54	113	return (dst);
	114	}
	115
	116	/* const char *
	117	* inet_ntop6(src, dst, size)
	118	* convert IPv6 binary address into presentation (printable) format
	119	* author:
	120	* Paul Vixie, 1996.
	121	*/
	122	static const char *
	123	inet_ntop6(src, dst, size)
	124	const u_char *src;
	125	char *dst;
	126	size_t size;
	127	{
	128	/*
	129	* Note that int32_t and int16_t need only be "at least" large enough
	130	* to contain a value of the specified size. On some systems, like
	131	* Crays, there is no such thing as an integer variable with 16 bits.
	132	* Keep this in mind if you think this function should have been coded
	133	* to use pointer overlays. All the world's not a VAX.
	134	*/
ac8802eb	135	char tmp[sizeof "ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255"];
ac8802eb	136	char tp, ep;
a704dd54	137	struct { int base, len; } best, cur;
	138	u_int words[IN6ADDRSZ / INT16SZ];
	139	int i;
ac8802eb	140	int advance;
a704dd54	141
	142	/*
	143	* Preprocess:
	144	* Copy the input (bytewise) array into a wordwise array.
	145	* Find the longest run of 0x00's in src[] for :: shorthanding.
	146	*/
	147	memset(words, '\0', sizeof words);
	148	for (i = 0; i < IN6ADDRSZ; i++)
	149	words[i / 2] \|= (src[i] << ((1 - (i % 2)) << 3));
	150	best.base = -1;
	151	cur.base = -1;
	152	for (i = 0; i < (IN6ADDRSZ / INT16SZ); i++) {
	153	if (words[i] == 0) {
	154	if (cur.base == -1)
	155	cur.base = i, cur.len = 1;
	156	else
	157	cur.len++;
	158	} else {
	159	if (cur.base != -1) {
	160	if (best.base == -1 \|\| cur.len > best.len)
	161	best = cur;
	162	cur.base = -1;
	163	}
	164	}
	165	}
	166	if (cur.base != -1) {
	167	if (best.base == -1 \|\| cur.len > best.len)
	168	best = cur;
	169	}
	170	if (best.base != -1 && best.len < 2)
	171	best.base = -1;
	172
	173	/*
	174	* Format the result.
	175	*/
	176	tp = tmp;
ac8802eb	177	ep = tmp + sizeof(tmp);
ac8802eb	178	for (i = 0; i < (IN6ADDRSZ / INT16SZ) && tp < ep; i++) {
a704dd54	179	/* Are we inside the best run of 0x00's? */
	180	if (best.base != -1 && i >= best.base &&
	181	i < (best.base + best.len)) {
ac8802eb	182	if (i == best.base) {
	183	if (tp + 1 >= ep)
	184	return (NULL);
a704dd54	185	*tp++ = ':';
ac8802eb	186	}
a704dd54	187	continue;
	188	}
	189	/* Are we following an initial run of 0x00s or any real hex? */
ac8802eb	190	if (i != 0) {
	191	if (tp + 1 >= ep)
	192	return (NULL);
a704dd54	193	*tp++ = ':';
ac8802eb	194	}
a704dd54	195	/* Is this address an encapsulated IPv4? */
	196	if (i == 6 && best.base == 0 &&
	197	(best.len == 6 \|\| (best.len == 5 && words[5] == 0xffff))) {
ac8802eb	198	if (!inet_ntop4(src+12, tp, (size_t)(ep - tp)))
a704dd54	199	return (NULL);
	200	tp += strlen(tp);
	201	break;
	202	}
ac8802eb	203	advance = snprintf(tp, ep - tp, "%x", words[i]);
	204	if (advance <= 0 \|\| advance >= ep - tp)
	205	return (NULL);
	206	tp += advance;
a704dd54	207	}
a704dd54	208	/* Was it a trailing run of 0x00's? */
ac8802eb	209	if (best.base != -1 && (best.base + best.len) == (IN6ADDRSZ / INT16SZ)) {
	210	if (tp + 1 >= ep)
	211	return (NULL);
a704dd54	212	*tp++ = ':';
ac8802eb	213	}
	214	if (tp + 1 >= ep)
	215	return (NULL);
a704dd54	216	*tp++ = '\0';
	217
	218	/*
	219	* Check for overflow, copy, and we're done.
	220	*/
	221	if ((size_t)(tp - tmp) > size) {
	222	errno = ENOSPC;
	223	return (NULL);
	224	}
ac8802eb	225	strlcpy(dst, tmp, size);
a704dd54	226	return (dst);
	227	}
	228
	229	#endif /* !HAVE_INET_NTOP */