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

/*	$OpenBSD: inet_ntop.c,v 1.1 1997/03/13 19:07:32 downsj 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 "config.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 1.1 1997/03/13 19:07:32 downsj Exp $";
#endif
#endif /* LIBC_SCCS and not lint */

#include <sys/param.h>
#include <sys/types.h>
#include <sys/socket.h>
#include "openbsd-compat/fake-socket.h"
#include <netinet/in.h>
#include <arpa/inet.h>
#ifndef HAVE_CYGWIN
#include <arpa/nameser.h>
#endif
#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 __P((const u_char *src, char *dst, size_t size));
static const char *inet_ntop6 __P((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"];

	if (sprintf(tmp, fmt, src[0], src[1], src[2], src[3]) > size) {
		errno = ENOSPC;
		return (NULL);
	}
	strcpy(dst, tmp);
	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"], *tp;
	struct { int base, len; } best, cur;
	u_int words[IN6ADDRSZ / INT16SZ];
	int i;

	/*
	 * 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;
	for (i = 0; i < (IN6ADDRSZ / INT16SZ); 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)
				*tp++ = ':';
			continue;
		}
		/* Are we following an initial run of 0x00s or any real hex? */
		if (i != 0)
			*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, sizeof tmp - (tp - tmp)))
				return (NULL);
			tp += strlen(tp);
			break;
		}
		tp += sprintf(tp, "%x", words[i]);
	}
	/* Was it a trailing run of 0x00's? */
	if (best.base != -1 && (best.base + best.len) == (IN6ADDRSZ / INT16SZ))
		*tp++ = ':';
	*tp++ = '\0';

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

#endif /* !HAVE_INET_NTOP */
Commit	Line	Data
a704dd54	1	/* $OpenBSD: inet_ntop.c,v 1.1 1997/03/13 19:07:32 downsj Exp $ */
	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
	19	#include "config.h"
	20
	21	#ifndef HAVE_INET_NTOP
	22
	23	#if defined(LIBC_SCCS) && !defined(lint)
	24	#if 0
	25	static char rcsid[] = "$From: inet_ntop.c,v 8.7 1996/08/05 08:41:18 vixie Exp $";
	26	#else
	27	static char rcsid[] = "$OpenBSD: inet_ntop.c,v 1.1 1997/03/13 19:07:32 downsj Exp $";
	28	#endif
	29	#endif /* LIBC_SCCS and not lint */
	30
	31	#include <sys/param.h>
	32	#include <sys/types.h>
	33	#include <sys/socket.h>
	34	#include "openbsd-compat/fake-socket.h"
	35	#include <netinet/in.h>
	36	#include <arpa/inet.h>
	37	#ifndef HAVE_CYGWIN
	38	#include <arpa/nameser.h>
	39	#endif
	40	#include <string.h>
	41	#include <errno.h>
	42	#include <stdio.h>
	43
	44	#ifndef IN6ADDRSZ
	45	#define IN6ADDRSZ 16 /* IPv6 T_AAAA */
	46	#endif
	47
	48	#ifndef INT16SZ
	49	#define INT16SZ 2 /* for systems without 16-bit ints */
	50	#endif
	51
	52	/*
	53	* WARNING: Don't even consider trying to compile this on a system where
	54	* sizeof(int) < 4. sizeof(int) > 4 is fine; all the world's not a VAX.
	55	*/
	56
	57	static const char inet_ntop4 __P((const u_char src, char *dst, size_t size));
	58	static const char inet_ntop6 __P((const u_char src, char *dst, size_t size));
	59
	60	/* char *
	61	* inet_ntop(af, src, dst, size)
	62	* convert a network format address to presentation format.
	63	* return:
	64	* pointer to presentation format address (`dst'), or NULL (see errno).
65	* author:
66	* Paul Vixie, 1996.
67	*/
68	const char *
69	inet_ntop(af, src, dst, size)
70	int af;
71	const void *src;
72	char *dst;
73	size_t size;
74	{
75	switch (af) {
76	case AF_INET:
77	return (inet_ntop4(src, dst, size));
78	case AF_INET6:
79	return (inet_ntop6(src, dst, size));
80	default:
81	errno = EAFNOSUPPORT;
82	return (NULL);
83	}
84	/* NOTREACHED */
85	}
86
87	/* const char *
88	* inet_ntop4(src, dst, size)
89	* format an IPv4 address, more or less like inet_ntoa()
90	* return:
91	* `dst' (as a const)
92	* notes:
93	* (1) uses no statics
94	* (2) takes a u_char* not an in_addr as input
95	* author:
96	* Paul Vixie, 1996.
97	*/
98	static const char *
99	inet_ntop4(src, dst, size)
100	const u_char *src;
101	char *dst;
102	size_t size;
103	{
104	static const char fmt[] = "%u.%u.%u.%u";
105	char tmp[sizeof "255.255.255.255"];
106
107	if (sprintf(tmp, fmt, src[0], src[1], src[2], src[3]) > size) {
108	errno = ENOSPC;
109	return (NULL);
110	}
111	strcpy(dst, tmp);
112	return (dst);
113	}
114
115	/* const char *
116	* inet_ntop6(src, dst, size)
117	* convert IPv6 binary address into presentation (printable) format
118	* author:
119	* Paul Vixie, 1996.
120	*/
121	static const char *
122	inet_ntop6(src, dst, size)
123	const u_char *src;
124	char *dst;
125	size_t size;
126	{
127	/*
128	* Note that int32_t and int16_t need only be "at least" large enough
129	* to contain a value of the specified size. On some systems, like
130	* Crays, there is no such thing as an integer variable with 16 bits.
131	* Keep this in mind if you think this function should have been coded
132	* to use pointer overlays. All the world's not a VAX.
133	*/
134	char tmp[sizeof "ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255"], *tp;
135	struct { int base, len; } best, cur;
136	u_int words[IN6ADDRSZ / INT16SZ];
137	int i;
138
139	/*
140	* Preprocess:
141	* Copy the input (bytewise) array into a wordwise array.
142	* Find the longest run of 0x00's in src[] for :: shorthanding.
143	*/
144	memset(words, '\0', sizeof words);
145	for (i = 0; i < IN6ADDRSZ; i++)
146	words[i / 2] \|= (src[i] << ((1 - (i % 2)) << 3));
147	best.base = -1;
148	cur.base = -1;
149	for (i = 0; i < (IN6ADDRSZ / INT16SZ); i++) {
150	if (words[i] == 0) {
151	if (cur.base == -1)
152	cur.base = i, cur.len = 1;
153	else
154	cur.len++;
155	} else {
156	if (cur.base != -1) {
157	if (best.base == -1 \|\| cur.len > best.len)
158	best = cur;
159	cur.base = -1;
160	}
161	}
162	}
163	if (cur.base != -1) {
164	if (best.base == -1 \|\| cur.len > best.len)
165	best = cur;
166	}
167	if (best.base != -1 && best.len < 2)
168	best.base = -1;
169
170	/*
171	* Format the result.
172	*/
173	tp = tmp;
174	for (i = 0; i < (IN6ADDRSZ / INT16SZ); i++) {
175	/* Are we inside the best run of 0x00's? */
176	if (best.base != -1 && i >= best.base &&
177	i < (best.base + best.len)) {
178	if (i == best.base)
179	*tp++ = ':';
180	continue;
181	}
182	/* Are we following an initial run of 0x00s or any real hex? */
183	if (i != 0)
184	*tp++ = ':';
185	/* Is this address an encapsulated IPv4? */
186	if (i == 6 && best.base == 0 &&
187	(best.len == 6 \|\| (best.len == 5 && words[5] == 0xffff))) {
188	if (!inet_ntop4(src+12, tp, sizeof tmp - (tp - tmp)))
189	return (NULL);
190	tp += strlen(tp);
191	break;
192	}
193	tp += sprintf(tp, "%x", words[i]);
194	}
195	/* Was it a trailing run of 0x00's? */
196	if (best.base != -1 && (best.base + best.len) == (IN6ADDRSZ / INT16SZ))
197	*tp++ = ':';
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	}
207	strcpy(dst, tmp);
208	return (dst);
209	}
210
211	#endif /* !HAVE_INET_NTOP */