1/*-
2 * SPDX-License-Identifier: ISC
3 *
4 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
5 * Copyright (c) 1998,1999 by Internet Software Consortium.
6 *
7 * Permission to use, copy, modify, and distribute this software for any
8 * purpose with or without fee is hereby granted, provided that the above
9 * copyright notice and this permission notice appear in all copies.
10 *
11 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
12 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13 * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
14 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
17 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18 */
19
20#if defined(LIBC_SCCS) && !defined(lint)
21static const char rcsid[] = "$Id: inet_cidr_pton.c,v 1.6 2005/04/27 04:56:19 sra Exp $";
22#endif
23#include <sys/cdefs.h>
24__FBSDID("$FreeBSD$");
25
26#include "port_before.h"
27
28#include <sys/types.h>
29#include <sys/socket.h>
30#include <netinet/in.h>
31#include <arpa/nameser.h>
32#include <arpa/inet.h>
33
34#include <assert.h>
35#include <ctype.h>
36#include <errno.h>
37#include <stdio.h>
38#include <string.h>
39#include <stdlib.h>
40
41#include "port_after.h"
42
43#ifdef SPRINTF_CHAR
44# define SPRINTF(x) strlen(sprintf/**/x)
45#else
46# define SPRINTF(x) ((size_t)sprintf x)
47#endif
48
49static int	inet_cidr_pton_ipv4 (const char *src, u_char *dst, int *bits,
50				     int ipv6);
51static int	inet_cidr_pton_ipv6 (const char *src, u_char *dst, int *bits);
52
53static int	getbits(const char *, int ipv6);
54
55/*%
56 * int
57 * inet_cidr_pton(af, src, dst, *bits)
58 *	convert network address from presentation to network format.
59 *	accepts inet_pton()'s input for this "af" plus trailing "/CIDR".
60 *	"dst" is assumed large enough for its "af".  "bits" is set to the
61 *	/CIDR prefix length, which can have defaults (like /32 for IPv4).
62 * return:
63 *	-1 if an error occurred (inspect errno; ENOENT means bad format).
64 *	0 if successful conversion occurred.
65 * note:
66 *	192.5.5.1/28 has a nonzero host part, which means it isn't a network
67 *	as called for by inet_net_pton() but it can be a host address with
68 *	an included netmask.
69 * author:
70 *	Paul Vixie (ISC), October 1998
71 */
72int
73inet_cidr_pton(int af, const char *src, void *dst, int *bits) {
74	switch (af) {
75	case AF_INET:
76		return (inet_cidr_pton_ipv4(src, dst, bits, 0));
77	case AF_INET6:
78		return (inet_cidr_pton_ipv6(src, dst, bits));
79	default:
80		errno = EAFNOSUPPORT;
81		return (-1);
82	}
83}
84
85static const char digits[] = "0123456789";
86
87static int
88inet_cidr_pton_ipv4(const char *src, u_char *dst, int *pbits, int ipv6) {
89	const u_char *odst = dst;
90	int n, ch, tmp, bits;
91	size_t size = 4;
92
93	/* Get the mantissa. */
94	while (ch = *src++, (isascii(ch) && isdigit(ch))) {
95		tmp = 0;
96		do {
97			n = strchr(digits, ch) - digits;
98			assert(n >= 0 && n <= 9);
99			tmp *= 10;
100			tmp += n;
101			if (tmp > 255)
102				goto enoent;
103		} while ((ch = *src++) != '\0' && isascii(ch) && isdigit(ch));
104		if (size-- == 0U)
105			goto emsgsize;
106		*dst++ = (u_char) tmp;
107		if (ch == '\0' || ch == '/')
108			break;
109		if (ch != '.')
110			goto enoent;
111	}
112
113	/* Get the prefix length if any. */
114	bits = -1;
115	if (ch == '/' && dst > odst) {
116		bits = getbits(src, ipv6);
117		if (bits == -2)
118			goto enoent;
119	} else if (ch != '\0')
120		goto enoent;
121
122	/* Prefix length can default to /32 only if all four octets spec'd. */
123	if (bits == -1) {
124		if (dst - odst == 4)
125			bits = ipv6 ? 128 : 32;
126		else
127			goto enoent;
128	}
129
130	/* If nothing was written to the destination, we found no address. */
131	if (dst == odst)
132		goto enoent;
133
134	/* If prefix length overspecifies mantissa, life is bad. */
135	if (((bits - (ipv6 ? 96 : 0)) / 8) > (dst - odst))
136		goto enoent;
137
138	/* Extend address to four octets. */
139	while (size-- > 0U)
140		*dst++ = 0;
141
142	*pbits = bits;
143	return (0);
144
145 enoent:
146	errno = ENOENT;
147	return (-1);
148
149 emsgsize:
150	errno = EMSGSIZE;
151	return (-1);
152}
153
154static int
155inet_cidr_pton_ipv6(const char *src, u_char *dst, int *pbits) {
156	static const char xdigits_l[] = "0123456789abcdef",
157			  xdigits_u[] = "0123456789ABCDEF";
158	u_char tmp[NS_IN6ADDRSZ], *tp, *endp, *colonp;
159	const char *xdigits, *curtok;
160	int ch, saw_xdigit;
161	u_int val;
162	int bits;
163
164	memset((tp = tmp), '\0', NS_IN6ADDRSZ);
165	endp = tp + NS_IN6ADDRSZ;
166	colonp = NULL;
167	/* Leading :: requires some special handling. */
168	if (*src == ':')
169		if (*++src != ':')
170			return (0);
171	curtok = src;
172	saw_xdigit = 0;
173	val = 0;
174	bits = -1;
175	while ((ch = *src++) != '\0') {
176		const char *pch;
177
178		if ((pch = strchr((xdigits = xdigits_l), ch)) == NULL)
179			pch = strchr((xdigits = xdigits_u), ch);
180		if (pch != NULL) {
181			val <<= 4;
182			val |= (pch - xdigits);
183			if (val > 0xffff)
184				return (0);
185			saw_xdigit = 1;
186			continue;
187		}
188		if (ch == ':') {
189			curtok = src;
190			if (!saw_xdigit) {
191				if (colonp)
192					return (0);
193				colonp = tp;
194				continue;
195			} else if (*src == '\0') {
196				return (0);
197			}
198			if (tp + NS_INT16SZ > endp)
199				return (0);
200			*tp++ = (u_char) (val >> 8) & 0xff;
201			*tp++ = (u_char) val & 0xff;
202			saw_xdigit = 0;
203			val = 0;
204			continue;
205		}
206		if (ch == '.' && ((tp + NS_INADDRSZ) <= endp) &&
207		    inet_cidr_pton_ipv4(curtok, tp, &bits, 1) == 0) {
208			tp += NS_INADDRSZ;
209			saw_xdigit = 0;
210			break;	/*%< '\\0' was seen by inet_pton4(). */
211		}
212		if (ch == '/') {
213			bits = getbits(src, 1);
214			if (bits == -2)
215				goto enoent;
216			break;
217		}
218		goto enoent;
219	}
220	if (saw_xdigit) {
221		if (tp + NS_INT16SZ > endp)
222			goto emsgsize;
223		*tp++ = (u_char) (val >> 8) & 0xff;
224		*tp++ = (u_char) val & 0xff;
225	}
226	if (colonp != NULL) {
227		/*
228		 * Since some memmove()'s erroneously fail to handle
229		 * overlapping regions, we'll do the shift by hand.
230		 */
231		const int n = tp - colonp;
232		int i;
233
234		if (tp == endp)
235			goto enoent;
236		for (i = 1; i <= n; i++) {
237			endp[- i] = colonp[n - i];
238			colonp[n - i] = 0;
239		}
240		tp = endp;
241	}
242
243	memcpy(dst, tmp, NS_IN6ADDRSZ);
244
245	*pbits = bits;
246	return (0);
247
248 enoent:
249	errno = ENOENT;
250	return (-1);
251
252 emsgsize:
253	errno = EMSGSIZE;
254	return (-1);
255}
256
257static int
258getbits(const char *src, int ipv6) {
259	int bits = 0;
260	char *cp, ch;
261
262	if (*src == '\0')			/*%< syntax */
263		return (-2);
264	do {
265		ch = *src++;
266		cp = strchr(digits, ch);
267		if (cp == NULL)			/*%< syntax */
268			return (-2);
269		bits *= 10;
270		bits += cp - digits;
271		if (bits == 0 && *src != '\0')	/*%< no leading zeros */
272			return (-2);
273		if (bits > (ipv6 ? 128 : 32))	/*%< range error */
274			return (-2);
275	} while (*src != '\0');
276
277	return (bits);
278}
279
280/*! \file */
281