1 /* $NetBSD: inet_cidr_pton.c,v 1.8 2012/03/20 17:08:13 matt Exp $ */
2
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 #include <sys/cdefs.h>
21 #if defined(LIBC_SCCS) && !defined(lint)
22 #if 0
23 static const char rcsid[] = "Id: inet_cidr_pton.c,v 1.6 2005/04/27 04:56:19 sra Exp";
24 #else
25 __RCSID("$NetBSD: inet_cidr_pton.c,v 1.8 2012/03/20 17:08:13 matt Exp $");
26 #endif
27 #endif
28
29 #include "port_before.h"
30
31 #include "namespace.h"
32 #include <sys/types.h>
33 #include <sys/socket.h>
34 #include <netinet/in.h>
35 #include <arpa/nameser.h>
36 #include <arpa/inet.h>
37
38 #include <isc/assertions.h>
39 #include <ctype.h>
40 #include <errno.h>
41 #include <stdio.h>
42 #include <string.h>
43 #include <stddef.h>
44 #include <stdlib.h>
45
46 #include "port_after.h"
47
48 #ifdef SPRINTF_CHAR
49 # define SPRINTF(x) strlen(sprintf/**/x)
50 #else
51 # define SPRINTF(x) ((size_t)sprintf x)
52 #endif
53
54 #ifdef __weak_alias
55 __weak_alias(inet_cidr_pton,_inet_cidr_pton)
56 #endif
57
58 static int inet_cidr_pton_ipv4(const char *src, u_char *dst,
59 int *bits, int ipv6);
60 static int inet_cidr_pton_ipv6(const char *src, u_char *dst, int *bits);
61
62 static int getbits(const char *, int ipv6);
63
64 /*%
65 * int
66 * inet_cidr_pton(af, src, dst, *bits)
67 * convert network address from presentation to network format.
68 * accepts inet_pton()'s input for this "af" plus trailing "/CIDR".
69 * "dst" is assumed large enough for its "af". "bits" is set to the
70 * /CIDR prefix length, which can have defaults (like /32 for IPv4).
71 * return:
72 * -1 if an error occurred (inspect errno; ENOENT means bad format).
73 * 0 if successful conversion occurred.
74 * note:
75 * 192.5.5.1/28 has a nonzero host part, which means it isn't a network
76 * as called for by inet_net_pton() but it can be a host address with
77 * an included netmask.
78 * author:
79 * Paul Vixie (ISC), October 1998
80 */
81 int
inet_cidr_pton(int af,const char * src,void * dst,int * bits)82 inet_cidr_pton(int af, const char *src, void *dst, int *bits) {
83 switch (af) {
84 case AF_INET:
85 return (inet_cidr_pton_ipv4(src, dst, bits, 0));
86 case AF_INET6:
87 return (inet_cidr_pton_ipv6(src, dst, bits));
88 default:
89 errno = EAFNOSUPPORT;
90 return (-1);
91 }
92 }
93
94 static const char digits[] = "0123456789";
95
96 static int
inet_cidr_pton_ipv4(const char * src,u_char * dst,int * pbits,int ipv6)97 inet_cidr_pton_ipv4(const char *src, u_char *dst, int *pbits, int ipv6) {
98 const u_char *odst = dst;
99 int ch, bits;
100 ptrdiff_t n, tmp;
101 size_t size = 4;
102
103 /* Get the mantissa. */
104 while (ch = *src++, (isascii(ch) && isdigit(ch))) {
105 tmp = 0;
106 do {
107 n = strchr(digits, ch) - digits;
108 INSIST(n >= 0 && n <= 9);
109 tmp *= 10;
110 tmp += n;
111 if (tmp > 255)
112 goto enoent;
113 } while ((ch = *src++) != '\0' && isascii(ch) && isdigit(ch));
114 if (size-- == 0U)
115 goto emsgsize;
116 *dst++ = (u_char) tmp;
117 if (ch == '\0' || ch == '/')
118 break;
119 if (ch != '.')
120 goto enoent;
121 }
122
123 /* Get the prefix length if any. */
124 bits = -1;
125 if (ch == '/' && dst > odst) {
126 bits = getbits(src, ipv6);
127 if (bits == -2)
128 goto enoent;
129 } else if (ch != '\0')
130 goto enoent;
131
132 /* Prefix length can default to /32 only if all four octets spec'd. */
133 if (bits == -1) {
134 if (dst - odst == 4)
135 bits = ipv6 ? 128 : 32;
136 else
137 goto enoent;
138 }
139
140 /* If nothing was written to the destination, we found no address. */
141 if (dst == odst)
142 goto enoent;
143
144 /* If prefix length overspecifies mantissa, life is bad. */
145 if (((bits - (ipv6 ? 96 : 0)) / 8) > (dst - odst))
146 goto enoent;
147
148 /* Extend address to four octets. */
149 while (size-- > 0U)
150 *dst++ = 0;
151
152 *pbits = bits;
153 return (0);
154
155 enoent:
156 errno = ENOENT;
157 return (-1);
158
159 emsgsize:
160 errno = EMSGSIZE;
161 return (-1);
162 }
163
164 static int
inet_cidr_pton_ipv6(const char * src,u_char * dst,int * pbits)165 inet_cidr_pton_ipv6(const char *src, u_char *dst, int *pbits) {
166 static const char xdigits_l[] = "0123456789abcdef",
167 xdigits_u[] = "0123456789ABCDEF";
168 u_char tmp[NS_IN6ADDRSZ], *tp, *endp, *colonp;
169 const char *xdigits, *curtok;
170 int ch, saw_xdigit;
171 u_int val;
172 int bits;
173
174 memset((tp = tmp), '\0', NS_IN6ADDRSZ);
175 endp = tp + NS_IN6ADDRSZ;
176 colonp = NULL;
177 /* Leading :: requires some special handling. */
178 if (*src == ':')
179 if (*++src != ':')
180 return (0);
181 curtok = src;
182 saw_xdigit = 0;
183 val = 0;
184 bits = -1;
185 while ((ch = *src++) != '\0') {
186 const char *pch;
187
188 if ((pch = strchr((xdigits = xdigits_l), ch)) == NULL)
189 pch = strchr((xdigits = xdigits_u), ch);
190 if (pch != NULL) {
191 val <<= 4;
192 val |= (int)(pch - xdigits);
193 if (val > 0xffff)
194 return (0);
195 saw_xdigit = 1;
196 continue;
197 }
198 if (ch == ':') {
199 curtok = src;
200 if (!saw_xdigit) {
201 if (colonp)
202 return (0);
203 colonp = tp;
204 continue;
205 } else if (*src == '\0') {
206 return (0);
207 }
208 if (tp + NS_INT16SZ > endp)
209 return (0);
210 *tp++ = (u_char) (val >> 8) & 0xff;
211 *tp++ = (u_char) val & 0xff;
212 saw_xdigit = 0;
213 val = 0;
214 continue;
215 }
216 if (ch == '.' && ((tp + NS_INADDRSZ) <= endp) &&
217 inet_cidr_pton_ipv4(curtok, tp, &bits, 1) == 0) {
218 tp += NS_INADDRSZ;
219 saw_xdigit = 0;
220 break; /*%< '\\0' was seen by inet_pton4(). */
221 }
222 if (ch == '/') {
223 bits = getbits(src, 1);
224 if (bits == -2)
225 goto enoent;
226 break;
227 }
228 goto enoent;
229 }
230 if (saw_xdigit) {
231 if (tp + NS_INT16SZ > endp)
232 goto emsgsize;
233 *tp++ = (u_char) (val >> 8) & 0xff;
234 *tp++ = (u_char) val & 0xff;
235 }
236 if (colonp != NULL) {
237 /*
238 * Since some memmove()'s erroneously fail to handle
239 * overlapping regions, we'll do the shift by hand.
240 */
241 const ptrdiff_t n = tp - colonp;
242 int i;
243
244 if (tp == endp)
245 goto enoent;
246 for (i = 1; i <= n; i++) {
247 endp[- i] = colonp[n - i];
248 colonp[n - i] = 0;
249 }
250 tp = endp;
251 }
252
253 memcpy(dst, tmp, NS_IN6ADDRSZ);
254
255 *pbits = bits;
256 return (0);
257
258 enoent:
259 errno = ENOENT;
260 return (-1);
261
262 emsgsize:
263 errno = EMSGSIZE;
264 return (-1);
265 }
266
267 static int
getbits(const char * src,int ipv6)268 getbits(const char *src, int ipv6) {
269 int bits = 0;
270 char *cp, ch;
271
272 if (*src == '\0') /*%< syntax */
273 return (-2);
274 do {
275 ch = *src++;
276 cp = strchr(digits, ch);
277 if (cp == NULL) /*%< syntax */
278 return (-2);
279 bits *= 10;
280 bits += (int)(cp - digits);
281 if (bits == 0 && *src != '\0') /*%< no leading zeros */
282 return (-2);
283 if (bits > (ipv6 ? 128 : 32)) /*%< range error */
284 return (-2);
285 } while (*src != '\0');
286
287 return (bits);
288 }
289
290 /*! \file */
291