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

/*	$OpenBSD: inet_ntop.c,v 1.7 2005/08/06 20:30:03 espie 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

#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(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(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(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
68b36828	1	/* $OpenBSD: inet_ntop.c,v 1.7 2005/08/06 20:30:03 espie 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
a704dd54	25	#include <sys/param.h>
	26	#include <sys/types.h>
	27	#include <sys/socket.h>
a704dd54	28	#include <netinet/in.h>
a704dd54	29	#include <arpa/inet.h>
a704dd54	30	#include <arpa/nameser.h>
a704dd54	31	#include <string.h>
	32	#include <errno.h>
	33	#include <stdio.h>
	34
	35	#ifndef IN6ADDRSZ
	36	#define IN6ADDRSZ 16 /* IPv6 T_AAAA */
	37	#endif
	38
	39	#ifndef INT16SZ
	40	#define INT16SZ 2 /* for systems without 16-bit ints */
	41	#endif
	42
	43	/*
	44	* WARNING: Don't even consider trying to compile this on a system where
	45	* sizeof(int) < 4. sizeof(int) > 4 is fine; all the world's not a VAX.
	46	*/
	47
ac8802eb	48	static const char inet_ntop4(const u_char src, char *dst, size_t size);
ac8802eb	49	static const char inet_ntop6(const u_char src, char *dst, size_t size);
a704dd54	50
	51	/* char *
	52	* inet_ntop(af, src, dst, size)
	53	* convert a network format address to presentation format.
	54	* return:
	55	* pointer to presentation format address (`dst'), or NULL (see errno).
	56	* author:
	57	* Paul Vixie, 1996.
	58	*/
	59	const char *
68b36828	60	inet_ntop(int af, const void src, char dst, size_t size)
a704dd54	61	{
	62	switch (af) {
	63	case AF_INET:
	64	return (inet_ntop4(src, dst, size));
	65	case AF_INET6:
	66	return (inet_ntop6(src, dst, size));
	67	default:
	68	errno = EAFNOSUPPORT;
	69	return (NULL);
	70	}
	71	/* NOTREACHED */
	72	}
	73
	74	/* const char *
	75	* inet_ntop4(src, dst, size)
	76	* format an IPv4 address, more or less like inet_ntoa()
	77	* return:
	78	* `dst' (as a const)
	79	* notes:
	80	* (1) uses no statics
	81	* (2) takes a u_char* not an in_addr as input
	82	* author:
	83	* Paul Vixie, 1996.
	84	*/
	85	static const char *
68b36828	86	inet_ntop4(const u_char src, char dst, size_t size)
a704dd54	87	{
	88	static const char fmt[] = "%u.%u.%u.%u";
	89	char tmp[sizeof "255.255.255.255"];
ac8802eb	90	int l;
a704dd54	91
ac8802eb	92	l = snprintf(tmp, size, fmt, src[0], src[1], src[2], src[3]);
ac8802eb	93	if (l <= 0 \|\| l >= size) {
a704dd54	94	errno = ENOSPC;
	95	return (NULL);
	96	}
ac8802eb	97	strlcpy(dst, tmp, size);
a704dd54	98	return (dst);
	99	}
	100
	101	/* const char *
	102	* inet_ntop6(src, dst, size)
	103	* convert IPv6 binary address into presentation (printable) format
	104	* author:
	105	* Paul Vixie, 1996.
	106	*/
	107	static const char *
68b36828	108	inet_ntop6(const u_char src, char dst, size_t size)
a704dd54	109	{
	110	/*
	111	* Note that int32_t and int16_t need only be "at least" large enough
	112	* to contain a value of the specified size. On some systems, like
	113	* Crays, there is no such thing as an integer variable with 16 bits.
	114	* Keep this in mind if you think this function should have been coded
	115	* to use pointer overlays. All the world's not a VAX.
	116	*/
ac8802eb	117	char tmp[sizeof "ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255"];
ac8802eb	118	char tp, ep;
a704dd54	119	struct { int base, len; } best, cur;
	120	u_int words[IN6ADDRSZ / INT16SZ];
	121	int i;
ac8802eb	122	int advance;
a704dd54	123
	124	/*
	125	* Preprocess:
	126	* Copy the input (bytewise) array into a wordwise array.
	127	* Find the longest run of 0x00's in src[] for :: shorthanding.
	128	*/
	129	memset(words, '\0', sizeof words);
	130	for (i = 0; i < IN6ADDRSZ; i++)
	131	words[i / 2] \|= (src[i] << ((1 - (i % 2)) << 3));
	132	best.base = -1;
	133	cur.base = -1;
	134	for (i = 0; i < (IN6ADDRSZ / INT16SZ); i++) {
	135	if (words[i] == 0) {
	136	if (cur.base == -1)
	137	cur.base = i, cur.len = 1;
	138	else
	139	cur.len++;
	140	} else {
	141	if (cur.base != -1) {
	142	if (best.base == -1 \|\| cur.len > best.len)
	143	best = cur;
	144	cur.base = -1;
	145	}
	146	}
	147	}
	148	if (cur.base != -1) {
	149	if (best.base == -1 \|\| cur.len > best.len)
	150	best = cur;
	151	}
	152	if (best.base != -1 && best.len < 2)
	153	best.base = -1;
	154
	155	/*
	156	* Format the result.
	157	*/
	158	tp = tmp;
ac8802eb	159	ep = tmp + sizeof(tmp);
ac8802eb	160	for (i = 0; i < (IN6ADDRSZ / INT16SZ) && tp < ep; i++) {
a704dd54	161	/* Are we inside the best run of 0x00's? */
	162	if (best.base != -1 && i >= best.base &&
	163	i < (best.base + best.len)) {
ac8802eb	164	if (i == best.base) {
	165	if (tp + 1 >= ep)
	166	return (NULL);
a704dd54	167	*tp++ = ':';
ac8802eb	168	}
a704dd54	169	continue;
	170	}
	171	/* Are we following an initial run of 0x00s or any real hex? */
ac8802eb	172	if (i != 0) {
	173	if (tp + 1 >= ep)
	174	return (NULL);
a704dd54	175	*tp++ = ':';
ac8802eb	176	}
a704dd54	177	/* Is this address an encapsulated IPv4? */
	178	if (i == 6 && best.base == 0 &&
	179	(best.len == 6 \|\| (best.len == 5 && words[5] == 0xffff))) {
ac8802eb	180	if (!inet_ntop4(src+12, tp, (size_t)(ep - tp)))
a704dd54	181	return (NULL);
	182	tp += strlen(tp);
	183	break;
	184	}
ac8802eb	185	advance = snprintf(tp, ep - tp, "%x", words[i]);
	186	if (advance <= 0 \|\| advance >= ep - tp)
	187	return (NULL);
	188	tp += advance;
a704dd54	189	}
a704dd54	190	/* Was it a trailing run of 0x00's? */
ac8802eb	191	if (best.base != -1 && (best.base + best.len) == (IN6ADDRSZ / INT16SZ)) {
	192	if (tp + 1 >= ep)
	193	return (NULL);
a704dd54	194	*tp++ = ':';
ac8802eb	195	}
	196	if (tp + 1 >= ep)
	197	return (NULL);
a704dd54	198	*tp++ = '\0';
	199
	200	/*
	201	* Check for overflow, copy, and we're done.
	202	*/
	203	if ((size_t)(tp - tmp) > size) {
	204	errno = ENOSPC;
	205	return (NULL);
	206	}
ac8802eb	207	strlcpy(dst, tmp, size);
a704dd54	208	return (dst);
	209	}
	210
	211	#endif /* !HAVE_INET_NTOP */