1 /* Copyright (C) 1996-2023 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <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 <arpa/inet.h>
36 #include <arpa/nameser.h>
37 #include <ctype.h>
38 #include <errno.h>
39 #include <netinet/in.h>
40 #include <resolv/resolv-internal.h>
41 #include <string.h>
42 #include <sys/socket.h>
43 #include <sys/types.h>
44
45 static int inet_pton4 (const char *src, const char *src_end, u_char *dst);
46 static int inet_pton6 (const char *src, const char *src_end, u_char *dst);
47
48 int
49 __inet_pton_length (int af, const char *src, size_t srclen, void *dst)
50 {
51 switch (af)
52 {
53 case AF_INET:
54 return inet_pton4 (src, src + srclen, dst);
55 case AF_INET6:
56 return inet_pton6 (src, src + srclen, dst);
57 default:
58 __set_errno (EAFNOSUPPORT);
59 return -1;
60 }
61 }
62 libc_hidden_def (__inet_pton_length)
63
64 /* Like __inet_pton_length, but use strlen (SRC) as the length of
65 SRC. */
66 int
67 __inet_pton (int af, const char *src, void *dst)
68 {
69 return __inet_pton_length (af, src, strlen (src), dst);
70 }
71 libc_hidden_def (__inet_pton)
72 weak_alias (__inet_pton, inet_pton)
73 libc_hidden_weak (inet_pton)
74
75 /* Like inet_aton but without all the hexadecimal, octal and shorthand
76 (and trailing garbage is not ignored). Return 1 if SRC is a valid
77 dotted quad, else 0. This function does not touch DST unless it's
78 returning 1.
79 Author: Paul Vixie, 1996. */
80 static int
81 inet_pton4 (const char *src, const char *end, unsigned char *dst)
82 {
83 int saw_digit, octets, ch;
84 unsigned char tmp[NS_INADDRSZ], *tp;
85
86 saw_digit = 0;
87 octets = 0;
88 *(tp = tmp) = 0;
89 while (src < end)
90 {
91 ch = *src++;
92 if (ch >= '0' && ch <= '9')
93 {
94 unsigned int new = *tp * 10 + (ch - '0');
95
96 if (saw_digit && *tp == 0)
97 return 0;
98 if (new > 255)
99 return 0;
100 *tp = new;
101 if (! saw_digit)
102 {
103 if (++octets > 4)
104 return 0;
105 saw_digit = 1;
106 }
107 }
108 else if (ch == '.' && saw_digit)
109 {
110 if (octets == 4)
111 return 0;
112 *++tp = 0;
113 saw_digit = 0;
114 }
115 else
116 return 0;
117 }
118 if (octets < 4)
119 return 0;
120 memcpy (dst, tmp, NS_INADDRSZ);
121 return 1;
122 }
123
124 /* Return the value of CH as a hexadecimal digit, or -1 if it is a
125 different type of character. */
126 static int
127 hex_digit_value (char ch)
128 {
129 if ('0' <= ch && ch <= '9')
130 return ch - '0';
131 if ('a' <= ch && ch <= 'f')
132 return ch - 'a' + 10;
133 if ('A' <= ch && ch <= 'F')
134 return ch - 'A' + 10;
135 return -1;
136 }
137
138 /* Convert presentation-level IPv6 address to network order binary
139 form. Return 1 if SRC is a valid [RFC1884 2.2] address, else 0.
140 This function does not touch DST unless it's returning 1.
141 Author: Paul Vixie, 1996. Inspired by Mark Andrews. */
142 static int
143 inet_pton6 (const char *src, const char *src_endp, unsigned char *dst)
144 {
145 unsigned char tmp[NS_IN6ADDRSZ], *tp, *endp, *colonp;
146 const char *curtok;
147 int ch;
148 size_t xdigits_seen; /* Number of hex digits since colon. */
149 unsigned int val;
150
151 tp = memset (tmp, '\0', NS_IN6ADDRSZ);
152 endp = tp + NS_IN6ADDRSZ;
153 colonp = NULL;
154
155 /* Leading :: requires some special handling. */
156 if (src == src_endp)
157 return 0;
158 if (*src == ':')
159 {
160 ++src;
161 if (src == src_endp || *src != ':')
162 return 0;
163 }
164
165 curtok = src;
166 xdigits_seen = 0;
167 val = 0;
168 while (src < src_endp)
169 {
170 ch = *src++;
171 int digit = hex_digit_value (ch);
172 if (digit >= 0)
173 {
174 if (xdigits_seen == 4)
175 return 0;
176 val <<= 4;
177 val |= digit;
178 if (val > 0xffff)
179 return 0;
180 ++xdigits_seen;
181 continue;
182 }
183 if (ch == ':')
184 {
185 curtok = src;
186 if (xdigits_seen == 0)
187 {
188 if (colonp)
189 return 0;
190 colonp = tp;
191 continue;
192 }
193 else if (src == src_endp)
194 return 0;
195 if (tp + NS_INT16SZ > endp)
196 return 0;
197 *tp++ = (unsigned char) (val >> 8) & 0xff;
198 *tp++ = (unsigned char) val & 0xff;
199 xdigits_seen = 0;
200 val = 0;
201 continue;
202 }
203 if (ch == '.' && ((tp + NS_INADDRSZ) <= endp)
204 && inet_pton4 (curtok, src_endp, tp) > 0)
205 {
206 tp += NS_INADDRSZ;
207 xdigits_seen = 0;
208 break; /* '\0' was seen by inet_pton4. */
209 }
210 return 0;
211 }
212 if (xdigits_seen > 0)
213 {
214 if (tp + NS_INT16SZ > endp)
215 return 0;
216 *tp++ = (unsigned char) (val >> 8) & 0xff;
217 *tp++ = (unsigned char) val & 0xff;
218 }
219 if (colonp != NULL)
220 {
221 /* Replace :: with zeros. */
222 if (tp == endp)
223 /* :: would expand to a zero-width field. */
224 return 0;
225 size_t n = tp - colonp;
226 memmove (endp - n, colonp, n);
227 memset (colonp, 0, endp - n - colonp);
228 tp = endp;
229 }
230 if (tp != endp)
231 return 0;
232 memcpy (dst, tmp, NS_IN6ADDRSZ);
233 return 1;
234 }