1/*
2 * Copyright (c) 1996,1999 by Internet Software Consortium.
3 *
4 * Permission to use, copy, modify, and distribute this software for any
5 * purpose with or without fee is hereby granted, provided that the above
6 * copyright notice and this permission notice appear in all copies.
7 *
8 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
9 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
10 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
11 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
12 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
13 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
14 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
15 * SOFTWARE.
16 */
17
18#include <sys/cdefs.h>
19#if defined(LIBC_SCCS) && !defined(lint)
20#if 0
21static const char rcsid[] = "Id: inet_net_pton.c,v 1.4.2.1 2002/08/02 02:17:21 marka Exp ";
22#else
23__RCSID("$NetBSD: inet_net_pton.c,v 1.4 2012/03/20 17:08:13 matt Exp $");
24#endif
25#endif
26
27#include "port_before.h"
28
29#include <sys/types.h>
30#include <sys/socket.h>
31#include <netinet/in.h>
32#include <arpa/nameser.h>
33#include <arpa/inet.h>
34
35#include <isc/assertions.h>
36#include <stddef.h>
37#include <ctype.h>
38#include <errno.h>
39#include <stdio.h>
40#include <string.h>
41#include <stdlib.h>
42
43#include "port_after.h"
44
45#ifdef __weak_alias
46__weak_alias(inet_net_pton,_inet_net_pton)
47#endif
48
49#ifdef SPRINTF_CHAR
50# define SPRINTF(x) strlen(sprintf/**/x)
51#else
52# define SPRINTF(x) ((size_t)sprintf x)
53#endif
54
55
56/*
57 * static int
58 * inet_net_pton_ipv4(src, dst, size)
59 *	convert IPv4 network number from presentation to network format.
60 *	accepts hex octets, hex strings, decimal octets, and /CIDR.
61 *	"size" is in bytes and describes "dst".
62 * return:
63 *	number of bits, either imputed classfully or specified with /CIDR,
64 *	or -1 if some failure occurred (check errno).  ENOENT means it was
65 *	not an IPv4 network specification.
66 * note:
67 *	network byte order assumed.  this means 192.5.5.240/28 has
68 *	0b11110000 in its fourth octet.
69 * author:
70 *	Paul Vixie (ISC), June 1996
71 */
72static int
73inet_net_pton_ipv4(const char *src, u_char *dst, size_t size)
74{
75	static const char xdigits[] = "0123456789abcdef";
76	static const char digits[] = "0123456789";
77	int ch, dirty, bits;
78	ptrdiff_t n, tmp;
79	const u_char *odst = dst;
80
81	tmp = 0;
82	ch = *src++;
83	if (ch == '0' && (src[0] == 'x' || src[0] == 'X')
84	    && isascii((u_char)(src[1]))
85	    && isxdigit((u_char)(src[1]))) {
86		/* Hexadecimal: Eat nybble string. */
87		if (size == 0)
88			goto emsgsize;
89		dirty = 0;
90		src++;	/* skip x or X. */
91		while ((ch = *src++) != '\0' && isascii((u_char)ch)
92		    && isxdigit((u_char)ch)) {
93			if (isupper((u_char)ch))
94				ch = tolower((u_char)ch);
95			n = strchr(xdigits, ch) - xdigits;
96			INSIST(n >= 0 && n <= 15);
97			if (dirty == 0)
98				tmp = n;
99			else
100				tmp = (tmp << 4) | n;
101			if (++dirty == 2) {
102				if (size-- == 0)
103					goto emsgsize;
104				*dst++ = (u_char) tmp;
105				dirty = 0;
106			}
107		}
108		if (dirty) {  /* Odd trailing nybble? */
109			if (size-- == 0)
110				goto emsgsize;
111			*dst++ = (u_char) (tmp << 4);
112		}
113	} else if (isascii((u_char)ch) && isdigit((u_char)ch)) {
114		/* Decimal: eat dotted digit string. */
115		for (;;) {
116			tmp = 0;
117			do {
118				n = strchr(digits, ch) - digits;
119				INSIST(n >= 0 && n <= 9);
120				tmp *= 10;
121				tmp += n;
122				if (tmp > 255)
123					goto enoent;
124			} while ((ch = *src++) != '\0' &&
125				 isascii((u_char)ch) && isdigit((u_char)ch));
126			if (size-- == 0)
127				goto emsgsize;
128			*dst++ = (u_char) tmp;
129			if (ch == '\0' || ch == '/')
130				break;
131			if (ch != '.')
132				goto enoent;
133			ch = *src++;
134			if (!isascii((u_char)ch) || !isdigit((u_char)ch))
135				goto enoent;
136		}
137	} else
138		goto enoent;
139
140	bits = -1;
141	if (ch == '/' && isascii((u_char)(src[0])) &&
142	    isdigit((u_char)(src[0])) && dst > odst) {
143		/* CIDR width specifier.  Nothing can follow it. */
144		ch = *src++;	/* Skip over the /. */
145		bits = 0;
146		do {
147			n = strchr(digits, ch) - digits;
148			INSIST(n >= 0 && n <= 9);
149			bits *= 10;
150			bits += (int)n;
151			if (bits > 32)
152				goto emsgsize;
153		} while ((ch = *src++) != '\0' && isascii((u_char)ch)
154		    && isdigit((u_char)ch));
155		if (ch != '\0')
156			goto enoent;
157	}
158
159	/* Firey death and destruction unless we prefetched EOS. */
160	if (ch != '\0')
161		goto enoent;
162
163	/* If nothing was written to the destination, we found no address. */
164	if (dst == odst)
165		goto enoent;
166	/* If no CIDR spec was given, infer width from net class. */
167	if (bits == -1) {
168		if (*odst >= 240)	/* Class E */
169			bits = 32;
170		else if (*odst >= 224)	/* Class D */
171			bits = 4;
172		else if (*odst >= 192)	/* Class C */
173			bits = 24;
174		else if (*odst >= 128)	/* Class B */
175			bits = 16;
176		else			/* Class A */
177			bits = 8;
178		/* If imputed mask is narrower than specified octets, widen. */
179		if (bits >= 8 && bits < ((dst - odst) * 8))
180			bits = (int)(dst - odst) * 8;
181	}
182	/* Extend network to cover the actual mask. */
183	while (bits > ((dst - odst) * 8)) {
184		if (size-- == 0)
185			goto emsgsize;
186		*dst++ = '\0';
187	}
188	return (bits);
189
190 enoent:
191	errno = ENOENT;
192	return (-1);
193
194 emsgsize:
195	errno = EMSGSIZE;
196	return (-1);
197}
198
199static int
200getbits(const char *src, int *bitsp)
201{
202	static const char digits[] = "0123456789";
203	int n;
204	int val;
205	char ch;
206
207	val = 0;
208	n = 0;
209	while ((ch = *src++) != '\0') {
210		const char *pch;
211
212		pch = strchr(digits, ch);
213		if (pch != NULL) {
214			if (n++ != 0 && val == 0)	/* no leading zeros */
215				return (0);
216			val *= 10;
217			val += (int)(pch - digits);
218			if (val > 128)			/* range */
219				return (0);
220			continue;
221		}
222		return (0);
223	}
224	if (n == 0)
225		return (0);
226	*bitsp = val;
227	return (1);
228}
229
230static int
231getv4(const char *src, u_char *dst, int *bitsp)
232{
233	static const char digits[] = "0123456789";
234	u_char *odst = dst;
235	int n;
236	u_int val;
237	char ch;
238
239	val = 0;
240	n = 0;
241	while ((ch = *src++) != '\0') {
242		const char *pch;
243
244		pch = strchr(digits, ch);
245		if (pch != NULL) {
246			if (n++ != 0 && val == 0)	/* no leading zeros */
247				return (0);
248			val *= 10;
249			val += (int)(pch - digits);
250			if (val > 255)			/* range */
251				return (0);
252			continue;
253		}
254		if (ch == '.' || ch == '/') {
255			if (dst - odst > 3)		/* too many octets? */
256				return (0);
257			*dst++ = val;
258			if (ch == '/')
259				return (getbits(src, bitsp));
260			val = 0;
261			n = 0;
262			continue;
263		}
264		return (0);
265	}
266	if (n == 0)
267		return (0);
268	if (dst - odst > 3)		/* too many octets? */
269		return (0);
270	*dst++ = val;
271	return (1);
272}
273
274static int
275inet_net_pton_ipv6(const char *src, u_char *dst, size_t size)
276{
277	static const char xdigits_l[] = "0123456789abcdef",
278			  xdigits_u[] = "0123456789ABCDEF";
279	u_char tmp[NS_IN6ADDRSZ], *tp, *endp, *colonp;
280	const char *xdigits, *curtok;
281	int ch, saw_xdigit;
282	u_int val;
283	int digits;
284	int bits;
285	size_t bytes;
286	int words;
287	int ipv4;
288
289	memset((tp = tmp), '\0', NS_IN6ADDRSZ);
290	endp = tp + NS_IN6ADDRSZ;
291	colonp = NULL;
292	/* Leading :: requires some special handling. */
293	if (*src == ':')
294		if (*++src != ':')
295			goto enoent;
296	curtok = src;
297	saw_xdigit = 0;
298	val = 0;
299	digits = 0;
300	bits = -1;
301	ipv4 = 0;
302	while ((ch = *src++) != '\0') {
303		const char *pch;
304
305		if ((pch = strchr((xdigits = xdigits_l), ch)) == NULL)
306			pch = strchr((xdigits = xdigits_u), ch);
307		if (pch != NULL) {
308			val <<= 4;
309			val |= (int)(pch - xdigits);
310			if (++digits > 4)
311				goto enoent;
312			saw_xdigit = 1;
313			continue;
314		}
315		if (ch == ':') {
316			curtok = src;
317			if (!saw_xdigit) {
318				if (colonp)
319					goto enoent;
320				colonp = tp;
321				continue;
322			} else if (*src == '\0')
323				goto enoent;
324			if (tp + NS_INT16SZ > endp)
325				return (0);
326			*tp++ = (u_char) (val >> 8) & 0xff;
327			*tp++ = (u_char) val & 0xff;
328			saw_xdigit = 0;
329			digits = 0;
330			val = 0;
331			continue;
332		}
333		if (ch == '.' && ((tp + NS_INADDRSZ) <= endp) &&
334		     getv4(curtok, tp, &bits) > 0) {
335			tp += NS_INADDRSZ;
336			saw_xdigit = 0;
337			ipv4 = 1;
338			break;	/* '\0' was seen by inet_pton4(). */
339		}
340		if (ch == '/' && getbits(src, &bits) > 0)
341			break;
342		goto enoent;
343	}
344	if (saw_xdigit) {
345		if (tp + NS_INT16SZ > endp)
346			goto enoent;
347		*tp++ = (u_char) (val >> 8) & 0xff;
348		*tp++ = (u_char) val & 0xff;
349	}
350	if (bits == -1)
351		bits = 128;
352
353	words = (bits + 15) / 16;
354	if (words < 2)
355		words = 2;
356	if (ipv4)
357		words = 8;
358	endp =  tmp + 2 * words;
359
360	if (colonp != NULL) {
361		/*
362		 * Since some memmove()'s erroneously fail to handle
363		 * overlapping regions, we'll do the shift by hand.
364		 */
365		const ptrdiff_t n = tp - colonp;
366		int i;
367
368		if (tp == endp)
369			goto enoent;
370		for (i = 1; i <= n; i++) {
371			endp[- i] = colonp[n - i];
372			colonp[n - i] = 0;
373		}
374		tp = endp;
375	}
376	if (tp != endp)
377		goto enoent;
378
379	bytes = (bits + 7) / 8;
380	if (bytes > size)
381		goto emsgsize;
382	memcpy(dst, tmp, bytes);
383	return (bits);
384
385 enoent:
386	errno = ENOENT;
387	return (-1);
388
389 emsgsize:
390	errno = EMSGSIZE;
391	return (-1);
392}
393
394/*
395 * int
396 * inet_net_pton(af, src, dst, size)
397 *	convert network number from presentation to network format.
398 *	accepts hex octets, hex strings, decimal octets, and /CIDR.
399 *	"size" is in bytes and describes "dst".
400 * return:
401 *	number of bits, either imputed classfully or specified with /CIDR,
402 *	or -1 if some failure occurred (check errno).  ENOENT means it was
403 *	not a valid network specification.
404 * author:
405 *	Paul Vixie (ISC), June 1996
406 */
407int
408inet_net_pton(int af, const char *src, void *dst, size_t size)
409{
410	switch (af) {
411	case AF_INET:
412		return (inet_net_pton_ipv4(src, dst, size));
413	case AF_INET6:
414		return (inet_net_pton_ipv6(src, dst, size));
415	default:
416		errno = EAFNOSUPPORT;
417		return (-1);
418	}
419}
420
421#undef inet_net_pton
422#pragma weak inet_net_pton = __inet_net_pton
423