1 /*
2 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
3 * Copyright (c) 1998,1999 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 ISC DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
15 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 */
17
18 #if defined(LIBC_SCCS) && !defined(lint)
19 static const char rcsid[] = "$Id: inet_cidr_pton.c,v 1.6 2005/04/27 04:56:19 sra Exp $";
20 #endif
21
22 #include "port_before.h"
23
24 #include <sys/types.h>
25 #include <sys/socket.h>
26 #include <netinet/in.h>
27 #include <arpa/nameser.h>
28 #include <arpa/inet.h>
29
30 #include <isc/assertions.h>
31 #include <ctype.h>
32 #include <errno.h>
33 #include <stdio.h>
34 #include <string.h>
35 #include <stdlib.h>
36
37 #include "port_after.h"
38
39 #ifdef SPRINTF_CHAR
40 # define SPRINTF(x) strlen(sprintf/**/x)
41 #else
42 # define SPRINTF(x) ((size_t)sprintf x)
43 #endif
44
45 static int inet_cidr_pton_ipv4 __P((const char *src, u_char *dst,
46 int *bits, int ipv6));
47 static int inet_cidr_pton_ipv6 __P((const char *src, u_char *dst,
48 int *bits));
49
50 static int getbits(const char *, int ipv6);
51
52 /*%
53 * int
54 * inet_cidr_pton(af, src, dst, *bits)
55 * convert network address from presentation to network format.
56 * accepts inet_pton()'s input for this "af" plus trailing "/CIDR".
57 * "dst" is assumed large enough for its "af". "bits" is set to the
58 * /CIDR prefix length, which can have defaults (like /32 for IPv4).
59 * return:
60 * -1 if an error occurred (inspect errno; ENOENT means bad format).
61 * 0 if successful conversion occurred.
62 * note:
63 * 192.5.5.1/28 has a nonzero host part, which means it isn't a network
64 * as called for by inet_net_pton() but it can be a host address with
65 * an included netmask.
66 * author:
67 * Paul Vixie (ISC), October 1998
68 */
69 int
inet_cidr_pton(int af,const char * src,void * dst,int * bits)70 inet_cidr_pton(int af, const char *src, void *dst, int *bits) {
71 switch (af) {
72 case AF_INET:
73 return (inet_cidr_pton_ipv4(src, dst, bits, 0));
74 case AF_INET6:
75 return (inet_cidr_pton_ipv6(src, dst, bits));
76 default:
77 errno = EAFNOSUPPORT;
78 return (-1);
79 }
80 }
81
82 static const char digits[] = "0123456789";
83
84 static int
inet_cidr_pton_ipv4(const char * src,u_char * dst,int * pbits,int ipv6)85 inet_cidr_pton_ipv4(const char *src, u_char *dst, int *pbits, int ipv6) {
86 const u_char *odst = dst;
87 int n, ch, tmp, bits;
88 size_t size = 4;
89
90 /* Get the mantissa. */
91 while (ch = *src++, (isascii(ch) && isdigit(ch))) {
92 tmp = 0;
93 do {
94 n = strchr(digits, ch) - digits;
95 INSIST(n >= 0 && n <= 9);
96 tmp *= 10;
97 tmp += n;
98 if (tmp > 255)
99 goto enoent;
100 } while ((ch = *src++) != '\0' && isascii(ch) && isdigit(ch));
101 if (size-- == 0U)
102 goto emsgsize;
103 *dst++ = (u_char) tmp;
104 if (ch == '\0' || ch == '/')
105 break;
106 if (ch != '.')
107 goto enoent;
108 }
109
110 /* Get the prefix length if any. */
111 bits = -1;
112 if (ch == '/' && dst > odst) {
113 bits = getbits(src, ipv6);
114 if (bits == -2)
115 goto enoent;
116 } else if (ch != '\0')
117 goto enoent;
118
119 /* Prefix length can default to /32 only if all four octets spec'd. */
120 if (bits == -1) {
121 if (dst - odst == 4)
122 bits = ipv6 ? 128 : 32;
123 else
124 goto enoent;
125 }
126
127 /* If nothing was written to the destination, we found no address. */
128 if (dst == odst)
129 goto enoent;
130
131 /* If prefix length overspecifies mantissa, life is bad. */
132 if (((bits - (ipv6 ? 96 : 0)) / 8) > (dst - odst))
133 goto enoent;
134
135 /* Extend address to four octets. */
136 while (size-- > 0U)
137 *dst++ = 0;
138
139 *pbits = bits;
140 return (0);
141
142 enoent:
143 errno = ENOENT;
144 return (-1);
145
146 emsgsize:
147 errno = EMSGSIZE;
148 return (-1);
149 }
150
151 static int
inet_cidr_pton_ipv6(const char * src,u_char * dst,int * pbits)152 inet_cidr_pton_ipv6(const char *src, u_char *dst, int *pbits) {
153 static const char xdigits_l[] = "0123456789abcdef",
154 xdigits_u[] = "0123456789ABCDEF";
155 u_char tmp[NS_IN6ADDRSZ], *tp, *endp, *colonp;
156 const char *xdigits, *curtok;
157 int ch, saw_xdigit;
158 u_int val;
159 int bits;
160
161 memset((tp = tmp), '\0', NS_IN6ADDRSZ);
162 endp = tp + NS_IN6ADDRSZ;
163 colonp = NULL;
164 /* Leading :: requires some special handling. */
165 if (*src == ':')
166 if (*++src != ':')
167 return (0);
168 curtok = src;
169 saw_xdigit = 0;
170 val = 0;
171 bits = -1;
172 while ((ch = *src++) != '\0') {
173 const char *pch;
174
175 if ((pch = strchr((xdigits = xdigits_l), ch)) == NULL)
176 pch = strchr((xdigits = xdigits_u), ch);
177 if (pch != NULL) {
178 val <<= 4;
179 val |= (pch - xdigits);
180 if (val > 0xffff)
181 return (0);
182 saw_xdigit = 1;
183 continue;
184 }
185 if (ch == ':') {
186 curtok = src;
187 if (!saw_xdigit) {
188 if (colonp)
189 return (0);
190 colonp = tp;
191 continue;
192 } else if (*src == '\0') {
193 return (0);
194 }
195 if (tp + NS_INT16SZ > endp)
196 return (0);
197 *tp++ = (u_char) (val >> 8) & 0xff;
198 *tp++ = (u_char) val & 0xff;
199 saw_xdigit = 0;
200 val = 0;
201 continue;
202 }
203 if (ch == '.' && ((tp + NS_INADDRSZ) <= endp) &&
204 inet_cidr_pton_ipv4(curtok, tp, &bits, 1) == 0) {
205 tp += NS_INADDRSZ;
206 saw_xdigit = 0;
207 break; /*%< '\\0' was seen by inet_pton4(). */
208 }
209 if (ch == '/') {
210 bits = getbits(src, 1);
211 if (bits == -2)
212 goto enoent;
213 break;
214 }
215 goto enoent;
216 }
217 if (saw_xdigit) {
218 if (tp + NS_INT16SZ > endp)
219 goto emsgsize;
220 *tp++ = (u_char) (val >> 8) & 0xff;
221 *tp++ = (u_char) val & 0xff;
222 }
223 if (colonp != NULL) {
224 /*
225 * Since some memmove()'s erroneously fail to handle
226 * overlapping regions, we'll do the shift by hand.
227 */
228 const int n = tp - colonp;
229 int i;
230
231 if (tp == endp)
232 goto enoent;
233 for (i = 1; i <= n; i++) {
234 endp[- i] = colonp[n - i];
235 colonp[n - i] = 0;
236 }
237 tp = endp;
238 }
239
240 memcpy(dst, tmp, NS_IN6ADDRSZ);
241
242 *pbits = bits;
243 return (0);
244
245 enoent:
246 errno = ENOENT;
247 return (-1);
248
249 emsgsize:
250 errno = EMSGSIZE;
251 return (-1);
252 }
253
254 static int
getbits(const char * src,int ipv6)255 getbits(const char *src, int ipv6) {
256 int bits = 0;
257 char *cp, ch;
258
259 if (*src == '\0') /*%< syntax */
260 return (-2);
261 do {
262 ch = *src++;
263 cp = strchr(digits, ch);
264 if (cp == NULL) /*%< syntax */
265 return (-2);
266 bits *= 10;
267 bits += cp - digits;
268 if (bits == 0 && *src != '\0') /*%< no leading zeros */
269 return (-2);
270 if (bits > (ipv6 ? 128 : 32)) /*%< range error */
271 return (-2);
272 } while (*src != '\0');
273
274 return (bits);
275 }
276
277 /*! \file */
278