xref: /freebsd/lib/libc/inet/inet_net_pton.c (revision f4b37ed0f8b307b1f3f0f630ca725d68f1dff30d)
1 /*
2  * Copyright (C) 2004, 2005, 2008  Internet Systems Consortium, Inc. ("ISC")
3  * Copyright (C) 1996, 1998, 1999, 2001, 2003  Internet Software Consortium.
4  *
5  * Permission to use, copy, modify, and/or 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 ISC DISCLAIMS ALL WARRANTIES WITH
10  * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
11  * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
12  * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
13  * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
14  * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
15  * PERFORMANCE OF THIS SOFTWARE.
16  */
17 
18 #if defined(LIBC_SCCS) && !defined(lint)
19 static const char rcsid[] = "$Id: inet_net_pton.c,v 1.10 2008/11/14 02:36:51 marka Exp $";
20 #endif
21 #include <sys/cdefs.h>
22 __FBSDID("$FreeBSD$");
23 
24 #include "port_before.h"
25 
26 #include <sys/types.h>
27 #include <sys/socket.h>
28 #include <netinet/in.h>
29 #include <arpa/nameser.h>
30 #include <arpa/inet.h>
31 
32 #include <assert.h>
33 #include <ctype.h>
34 #include <errno.h>
35 #include <stdio.h>
36 #include <string.h>
37 #include <stdlib.h>
38 
39 #include "port_after.h"
40 
41 #ifdef SPRINTF_CHAR
42 # define SPRINTF(x) strlen(sprintf/**/x)
43 #else
44 # define SPRINTF(x) ((size_t)sprintf x)
45 #endif
46 
47 /*%
48  * static int
49  * inet_net_pton_ipv4(src, dst, size)
50  *	convert IPv4 network number from presentation to network format.
51  *	accepts hex octets, hex strings, decimal octets, and /CIDR.
52  *	"size" is in bytes and describes "dst".
53  * return:
54  *	number of bits, either imputed classfully or specified with /CIDR,
55  *	or -1 if some failure occurred (check errno).  ENOENT means it was
56  *	not an IPv4 network specification.
57  * note:
58  *	network byte order assumed.  this means 192.5.5.240/28 has
59  *	0b11110000 in its fourth octet.
60  * author:
61  *	Paul Vixie (ISC), June 1996
62  */
63 static int
64 inet_net_pton_ipv4(const char *src, u_char *dst, size_t size) {
65 	static const char xdigits[] = "0123456789abcdef";
66 	static const char digits[] = "0123456789";
67 	int n, ch, tmp = 0, dirty, bits;
68 	const u_char *odst = dst;
69 
70 	ch = *src++;
71 	if (ch == '0' && (src[0] == 'x' || src[0] == 'X')
72 	    && isascii((unsigned char)(src[1]))
73 	    && isxdigit((unsigned char)(src[1]))) {
74 		/* Hexadecimal: Eat nybble string. */
75 		if (size <= 0U)
76 			goto emsgsize;
77 		dirty = 0;
78 		src++;	/*%< skip x or X. */
79 		while ((ch = *src++) != '\0' && isascii(ch) && isxdigit(ch)) {
80 			if (isupper(ch))
81 				ch = tolower(ch);
82 			n = strchr(xdigits, ch) - xdigits;
83 			assert(n >= 0 && n <= 15);
84 			if (dirty == 0)
85 				tmp = n;
86 			else
87 				tmp = (tmp << 4) | n;
88 			if (++dirty == 2) {
89 				if (size-- <= 0U)
90 					goto emsgsize;
91 				*dst++ = (u_char) tmp;
92 				dirty = 0;
93 			}
94 		}
95 		if (dirty) {  /*%< Odd trailing nybble? */
96 			if (size-- <= 0U)
97 				goto emsgsize;
98 			*dst++ = (u_char) (tmp << 4);
99 		}
100 	} else if (isascii(ch) && isdigit(ch)) {
101 		/* Decimal: eat dotted digit string. */
102 		for (;;) {
103 			tmp = 0;
104 			do {
105 				n = strchr(digits, ch) - digits;
106 				assert(n >= 0 && n <= 9);
107 				tmp *= 10;
108 				tmp += n;
109 				if (tmp > 255)
110 					goto enoent;
111 			} while ((ch = *src++) != '\0' &&
112 				 isascii(ch) && isdigit(ch));
113 			if (size-- <= 0U)
114 				goto emsgsize;
115 			*dst++ = (u_char) tmp;
116 			if (ch == '\0' || ch == '/')
117 				break;
118 			if (ch != '.')
119 				goto enoent;
120 			ch = *src++;
121 			if (!isascii(ch) || !isdigit(ch))
122 				goto enoent;
123 		}
124 	} else
125 		goto enoent;
126 
127 	bits = -1;
128 	if (ch == '/' && isascii((unsigned char)(src[0])) &&
129 	    isdigit((unsigned char)(src[0])) && dst > odst) {
130 		/* CIDR width specifier.  Nothing can follow it. */
131 		ch = *src++;	/*%< Skip over the /. */
132 		bits = 0;
133 		do {
134 			n = strchr(digits, ch) - digits;
135 			assert(n >= 0 && n <= 9);
136 			bits *= 10;
137 			bits += n;
138 			if (bits > 32)
139 				goto enoent;
140 		} while ((ch = *src++) != '\0' && isascii(ch) && isdigit(ch));
141 		if (ch != '\0')
142 			goto enoent;
143 	}
144 
145 	/* Firey death and destruction unless we prefetched EOS. */
146 	if (ch != '\0')
147 		goto enoent;
148 
149 	/* If nothing was written to the destination, we found no address. */
150 	if (dst == odst)
151 		goto enoent;
152 	/* If no CIDR spec was given, infer width from net class. */
153 	if (bits == -1) {
154 		if (*odst >= 240)	/*%< Class E */
155 			bits = 32;
156 		else if (*odst >= 224)	/*%< Class D */
157 			bits = 8;
158 		else if (*odst >= 192)	/*%< Class C */
159 			bits = 24;
160 		else if (*odst >= 128)	/*%< Class B */
161 			bits = 16;
162 		else			/*%< Class A */
163 			bits = 8;
164 		/* If imputed mask is narrower than specified octets, widen. */
165 		if (bits < ((dst - odst) * 8))
166 			bits = (dst - odst) * 8;
167 		/*
168 		 * If there are no additional bits specified for a class D
169 		 * address adjust bits to 4.
170 		 */
171 		if (bits == 8 && *odst == 224)
172 			bits = 4;
173 	}
174 	/* Extend network to cover the actual mask. */
175 	while (bits > ((dst - odst) * 8)) {
176 		if (size-- <= 0U)
177 			goto emsgsize;
178 		*dst++ = '\0';
179 	}
180 	return (bits);
181 
182  enoent:
183 	errno = ENOENT;
184 	return (-1);
185 
186  emsgsize:
187 	errno = EMSGSIZE;
188 	return (-1);
189 }
190 
191 static int
192 getbits(const char *src, int *bitsp) {
193 	static const char digits[] = "0123456789";
194 	int n;
195 	int val;
196 	char ch;
197 
198 	val = 0;
199 	n = 0;
200 	while ((ch = *src++) != '\0') {
201 		const char *pch;
202 
203 		pch = strchr(digits, ch);
204 		if (pch != NULL) {
205 			if (n++ != 0 && val == 0)	/*%< no leading zeros */
206 				return (0);
207 			val *= 10;
208 			val += (pch - digits);
209 			if (val > 128)			/*%< range */
210 				return (0);
211 			continue;
212 		}
213 		return (0);
214 	}
215 	if (n == 0)
216 		return (0);
217 	*bitsp = val;
218 	return (1);
219 }
220 
221 static int
222 getv4(const char *src, u_char *dst, int *bitsp) {
223 	static const char digits[] = "0123456789";
224 	u_char *odst = dst;
225 	int n;
226 	u_int val;
227 	char ch;
228 
229 	val = 0;
230 	n = 0;
231 	while ((ch = *src++) != '\0') {
232 		const char *pch;
233 
234 		pch = strchr(digits, ch);
235 		if (pch != NULL) {
236 			if (n++ != 0 && val == 0)	/*%< no leading zeros */
237 				return (0);
238 			val *= 10;
239 			val += (pch - digits);
240 			if (val > 255)			/*%< range */
241 				return (0);
242 			continue;
243 		}
244 		if (ch == '.' || ch == '/') {
245 			if (dst - odst > 3)		/*%< too many octets? */
246 				return (0);
247 			*dst++ = val;
248 			if (ch == '/')
249 				return (getbits(src, bitsp));
250 			val = 0;
251 			n = 0;
252 			continue;
253 		}
254 		return (0);
255 	}
256 	if (n == 0)
257 		return (0);
258 	if (dst - odst > 3)		/*%< too many octets? */
259 		return (0);
260 	*dst++ = val;
261 	return (1);
262 }
263 
264 static int
265 inet_net_pton_ipv6(const char *src, u_char *dst, size_t size) {
266 	static const char xdigits_l[] = "0123456789abcdef",
267 			  xdigits_u[] = "0123456789ABCDEF";
268 	u_char tmp[NS_IN6ADDRSZ], *tp, *endp, *colonp;
269 	const char *xdigits, *curtok;
270 	int ch, saw_xdigit;
271 	u_int val;
272 	int digits;
273 	int bits;
274 	size_t bytes;
275 	int words;
276 	int ipv4;
277 
278 	memset((tp = tmp), '\0', NS_IN6ADDRSZ);
279 	endp = tp + NS_IN6ADDRSZ;
280 	colonp = NULL;
281 	/* Leading :: requires some special handling. */
282 	if (*src == ':')
283 		if (*++src != ':')
284 			goto enoent;
285 	curtok = src;
286 	saw_xdigit = 0;
287 	val = 0;
288 	digits = 0;
289 	bits = -1;
290 	ipv4 = 0;
291 	while ((ch = *src++) != '\0') {
292 		const char *pch;
293 
294 		if ((pch = strchr((xdigits = xdigits_l), ch)) == NULL)
295 			pch = strchr((xdigits = xdigits_u), ch);
296 		if (pch != NULL) {
297 			val <<= 4;
298 			val |= (pch - xdigits);
299 			if (++digits > 4)
300 				goto enoent;
301 			saw_xdigit = 1;
302 			continue;
303 		}
304 		if (ch == ':') {
305 			curtok = src;
306 			if (!saw_xdigit) {
307 				if (colonp)
308 					goto enoent;
309 				colonp = tp;
310 				continue;
311 			} else if (*src == '\0')
312 				goto enoent;
313 			if (tp + NS_INT16SZ > endp)
314 				return (0);
315 			*tp++ = (u_char) (val >> 8) & 0xff;
316 			*tp++ = (u_char) val & 0xff;
317 			saw_xdigit = 0;
318 			digits = 0;
319 			val = 0;
320 			continue;
321 		}
322 		if (ch == '.' && ((tp + NS_INADDRSZ) <= endp) &&
323 		     getv4(curtok, tp, &bits) > 0) {
324 			tp += NS_INADDRSZ;
325 			saw_xdigit = 0;
326 			ipv4 = 1;
327 			break;	/*%< '\\0' was seen by inet_pton4(). */
328 		}
329 		if (ch == '/' && getbits(src, &bits) > 0)
330 			break;
331 		goto enoent;
332 	}
333 	if (saw_xdigit) {
334 		if (tp + NS_INT16SZ > endp)
335 			goto enoent;
336 		*tp++ = (u_char) (val >> 8) & 0xff;
337 		*tp++ = (u_char) val & 0xff;
338 	}
339 	if (bits == -1)
340 		bits = 128;
341 
342 	words = (bits + 15) / 16;
343 	if (words < 2)
344 		words = 2;
345 	if (ipv4)
346 		words = 8;
347 	endp =  tmp + 2 * words;
348 
349 	if (colonp != NULL) {
350 		/*
351 		 * Since some memmove()'s erroneously fail to handle
352 		 * overlapping regions, we'll do the shift by hand.
353 		 */
354 		const int n = tp - colonp;
355 		int i;
356 
357 		if (tp == endp)
358 			goto enoent;
359 		for (i = 1; i <= n; i++) {
360 			endp[- i] = colonp[n - i];
361 			colonp[n - i] = 0;
362 		}
363 		tp = endp;
364 	}
365 	if (tp != endp)
366 		goto enoent;
367 
368 	bytes = (bits + 7) / 8;
369 	if (bytes > size)
370 		goto emsgsize;
371 	memcpy(dst, tmp, bytes);
372 	return (bits);
373 
374  enoent:
375 	errno = ENOENT;
376 	return (-1);
377 
378  emsgsize:
379 	errno = EMSGSIZE;
380 	return (-1);
381 }
382 
383 /*%
384  * int
385  * inet_net_pton(af, src, dst, size)
386  *	convert network number from presentation to network format.
387  *	accepts hex octets, hex strings, decimal octets, and /CIDR.
388  *	"size" is in bytes and describes "dst".
389  * return:
390  *	number of bits, either imputed classfully or specified with /CIDR,
391  *	or -1 if some failure occurred (check errno).  ENOENT means it was
392  *	not a valid network specification.
393  * author:
394  *	Paul Vixie (ISC), June 1996
395  */
396 int
397 inet_net_pton(int af, const char *src, void *dst, size_t size) {
398 	switch (af) {
399 	case AF_INET:
400 		return (inet_net_pton_ipv4(src, dst, size));
401 	case AF_INET6:
402 		return (inet_net_pton_ipv6(src, dst, size));
403 	default:
404 		errno = EAFNOSUPPORT;
405 		return (-1);
406 	}
407 }
408 
409 /*
410  * Weak aliases for applications that use certain private entry points,
411  * and fail to include <arpa/inet.h>.
412  */
413 #undef inet_net_pton
414 __weak_reference(__inet_net_pton, inet_net_pton);
415 
416 /*! \file */
417