1 /* inet_pton.c -- convert IPv4 and IPv6 addresses from text to binary form
2
3 Copyright (C) 2006, 2008-2022 Free Software Foundation, Inc.
4
5 This file is free software: you can redistribute it and/or modify
6 it under the terms of the GNU Lesser General Public License as
7 published by the Free Software Foundation; either version 2.1 of the
8 License, or (at your option) any later version.
9
10 This file is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public License
16 along with this program. If not, see <https://www.gnu.org/licenses/>. */
17
18 /*
19 * Copyright (c) 1996,1999 by Internet Software Consortium.
20 *
21 * Permission to use, copy, modify, and distribute this software for any
22 * purpose with or without fee is hereby granted, provided that the above
23 * copyright notice and this permission notice appear in all copies.
24 *
25 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
26 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
27 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
28 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
29 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
30 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
31 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
32 * SOFTWARE.
33 */
34
35 #include <config.h>
36
37 /* Specification. */
38 #include <arpa/inet.h>
39
40 #if HAVE_DECL_INET_PTON
41
42 # undef inet_pton
43
44 int
45 rpl_inet_pton (int af, const char *restrict src, void *restrict dst)
46 {
47 return inet_pton (af, src, dst);
48 }
49
50 #else
51
52 # include <c-ctype.h>
53 # include <string.h>
54 # include <errno.h>
55
56 # define NS_INADDRSZ 4
57 # define NS_IN6ADDRSZ 16
58 # define NS_INT16SZ 2
59
60 /*
61 * WARNING: Don't even consider trying to compile this on a system where
62 * sizeof(int) < 4. sizeof(int) > 4 is fine; all the world's not a VAX.
63 */
64
65 static int inet_pton4 (const char *src, unsigned char *dst);
66 # if HAVE_IPV6
67 static int inet_pton6 (const char *src, unsigned char *dst);
68 # endif
69
70 /* int
71 * inet_pton(af, src, dst)
72 * convert from presentation format (which usually means ASCII printable)
73 * to network format (which is usually some kind of binary format).
74 * return:
75 * 1 if the address was valid for the specified address family
76 * 0 if the address wasn't valid ('dst' is untouched in this case)
77 * -1 if some other error occurred ('dst' is untouched in this case, too)
78 * author:
79 * Paul Vixie, 1996.
80 */
81 int
82 inet_pton (int af, const char *restrict src, void *restrict dst)
83 {
84 switch (af)
85 {
86 case AF_INET:
87 return (inet_pton4 (src, dst));
88
89 # if HAVE_IPV6
90 case AF_INET6:
91 return (inet_pton6 (src, dst));
92 # endif
93
94 default:
95 errno = EAFNOSUPPORT;
96 return (-1);
97 }
98 /* NOTREACHED */
99 }
100
101 /* int
102 * inet_pton4(src, dst)
103 * like inet_aton() but without all the hexadecimal, octal (with the
104 * exception of 0) and shorthand.
105 * return:
106 * 1 if 'src' is a valid dotted quad, else 0.
107 * notice:
108 * does not touch 'dst' unless it's returning 1.
109 * author:
110 * Paul Vixie, 1996.
111 */
112 static int
113 inet_pton4 (const char *restrict src, unsigned char *restrict dst)
114 {
115 int saw_digit, octets, ch;
116 unsigned char tmp[NS_INADDRSZ], *tp;
117
118 saw_digit = 0;
119 octets = 0;
120 *(tp = tmp) = 0;
121 while ((ch = *src++) != '\0')
122 {
123
124 if (ch >= '0' && ch <= '9')
125 {
126 unsigned new = *tp * 10 + (ch - '0');
127
128 if (saw_digit && *tp == 0)
129 return (0);
130 if (new > 255)
131 return (0);
132 *tp = new;
133 if (!saw_digit)
134 {
135 if (++octets > 4)
136 return (0);
137 saw_digit = 1;
138 }
139 }
140 else if (ch == '.' && saw_digit)
141 {
142 if (octets == 4)
143 return (0);
144 *++tp = 0;
145 saw_digit = 0;
146 }
147 else
148 return (0);
149 }
150 if (octets < 4)
151 return (0);
152 memcpy (dst, tmp, NS_INADDRSZ);
153 return (1);
154 }
155
156 # if HAVE_IPV6
157
158 /* int
159 * inet_pton6(src, dst)
160 * convert presentation level address to network order binary form.
161 * return:
162 * 1 if 'src' is a valid [RFC1884 2.2] address, else 0.
163 * notice:
164 * (1) does not touch 'dst' unless it's returning 1.
165 * (2) :: in a full address is silently ignored.
166 * credit:
167 * inspired by Mark Andrews.
168 * author:
169 * Paul Vixie, 1996.
170 */
171 static int
172 inet_pton6 (const char *restrict src, unsigned char *restrict dst)
173 {
174 static const char xdigits[] = "0123456789abcdef";
175 unsigned char tmp[NS_IN6ADDRSZ], *tp, *endp, *colonp;
176 const char *curtok;
177 int ch, saw_xdigit;
178 unsigned val;
179
180 tp = memset (tmp, '\0', NS_IN6ADDRSZ);
181 endp = tp + NS_IN6ADDRSZ;
182 colonp = NULL;
183 /* Leading :: requires some special handling. */
184 if (*src == ':')
185 if (*++src != ':')
186 return (0);
187 curtok = src;
188 saw_xdigit = 0;
189 val = 0;
190 while ((ch = c_tolower (*src++)) != '\0')
191 {
192 const char *pch;
193
194 pch = strchr (xdigits, ch);
195 if (pch != NULL)
196 {
197 val <<= 4;
198 val |= (pch - xdigits);
199 if (val > 0xffff)
200 return (0);
201 saw_xdigit = 1;
202 continue;
203 }
204 if (ch == ':')
205 {
206 curtok = src;
207 if (!saw_xdigit)
208 {
209 if (colonp)
210 return (0);
211 colonp = tp;
212 continue;
213 }
214 else if (*src == '\0')
215 {
216 return (0);
217 }
218 if (tp + NS_INT16SZ > endp)
219 return (0);
220 *tp++ = (u_char) (val >> 8) & 0xff;
221 *tp++ = (u_char) val & 0xff;
222 saw_xdigit = 0;
223 val = 0;
224 continue;
225 }
226 if (ch == '.' && ((tp + NS_INADDRSZ) <= endp) &&
227 inet_pton4 (curtok, tp) > 0)
228 {
229 tp += NS_INADDRSZ;
230 saw_xdigit = 0;
231 break; /* '\0' was seen by inet_pton4(). */
232 }
233 return (0);
234 }
235 if (saw_xdigit)
236 {
237 if (tp + NS_INT16SZ > endp)
238 return (0);
239 *tp++ = (u_char) (val >> 8) & 0xff;
240 *tp++ = (u_char) val & 0xff;
241 }
242 if (colonp != NULL)
243 {
244 /*
245 * Since some memmove()'s erroneously fail to handle
246 * overlapping regions, we'll do the shift by hand.
247 */
248 const int n = tp - colonp;
249 int i;
250
251 if (tp == endp)
252 return (0);
253 for (i = 1; i <= n; i++)
254 {
255 endp[-i] = colonp[n - i];
256 colonp[n - i] = 0;
257 }
258 tp = endp;
259 }
260 if (tp != endp)
261 return (0);
262 memcpy (dst, tmp, NS_IN6ADDRSZ);
263 return (1);
264 }
265
266 # endif
267
268 #endif