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8912421c LC |
1 | /* inet_ntop.c -- convert IPv4 and IPv6 addresses from binary to text form |
2 | ||
f0007cad | 3 | Copyright (C) 2005-2006, 2008-2012 Free Software Foundation, Inc. |
8912421c LC |
4 | |
5 | This program is free software; you can redistribute it and/or modify | |
6 | it under the terms of the GNU Lesser General Public License as published by | |
7 | the Free Software Foundation; either version 2, or (at your option) | |
8 | any later version. | |
9 | ||
10 | This program 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, write to the Free Software Foundation, | |
17 | Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ | |
18 | ||
19 | /* | |
20 | * Copyright (c) 1996-1999 by Internet Software Consortium. | |
21 | * | |
22 | * Permission to use, copy, modify, and distribute this software for any | |
23 | * purpose with or without fee is hereby granted, provided that the above | |
24 | * copyright notice and this permission notice appear in all copies. | |
25 | * | |
26 | * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS | |
27 | * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES | |
28 | * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE | |
29 | * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL | |
30 | * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR | |
31 | * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS | |
32 | * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS | |
33 | * SOFTWARE. | |
34 | */ | |
35 | ||
36 | #include <config.h> | |
37 | ||
38 | /* Specification. */ | |
39 | #include <arpa/inet.h> | |
40 | ||
f0007cad LC |
41 | /* Use this to suppress gcc's "...may be used before initialized" warnings. |
42 | Beware: The Code argument must not contain commas. */ | |
43 | #ifndef IF_LINT | |
44 | # ifdef lint | |
45 | # define IF_LINT(Code) Code | |
46 | # else | |
47 | # define IF_LINT(Code) /* empty */ | |
48 | # endif | |
49 | #endif | |
50 | ||
35428fb6 | 51 | #if HAVE_DECL_INET_NTOP |
8912421c | 52 | |
35428fb6 LC |
53 | # undef inet_ntop |
54 | ||
55 | const char * | |
56 | rpl_inet_ntop (int af, const void *restrict src, | |
57 | char *restrict dst, socklen_t cnt) | |
58 | { | |
59 | return inet_ntop (af, src, dst, cnt); | |
60 | } | |
61 | ||
62 | #else | |
63 | ||
64 | # include <stdio.h> | |
65 | # include <string.h> | |
66 | # include <errno.h> | |
67 | ||
68 | # define NS_IN6ADDRSZ 16 | |
69 | # define NS_INT16SZ 2 | |
8912421c LC |
70 | |
71 | /* | |
72 | * WARNING: Don't even consider trying to compile this on a system where | |
73 | * sizeof(int) < 4. sizeof(int) > 4 is fine; all the world's not a VAX. | |
74 | */ | |
0f00f2c3 | 75 | typedef int verify_int_size[4 <= sizeof (int) ? 1 : -1]; |
8912421c LC |
76 | |
77 | static const char *inet_ntop4 (const unsigned char *src, char *dst, socklen_t size); | |
35428fb6 | 78 | # if HAVE_IPV6 |
8912421c | 79 | static const char *inet_ntop6 (const unsigned char *src, char *dst, socklen_t size); |
35428fb6 | 80 | # endif |
8912421c LC |
81 | |
82 | ||
83 | /* char * | |
84 | * inet_ntop(af, src, dst, size) | |
1cd4fffc | 85 | * convert a network format address to presentation format. |
8912421c | 86 | * return: |
f0007cad | 87 | * pointer to presentation format address ('dst'), or NULL (see errno). |
8912421c | 88 | * author: |
1cd4fffc | 89 | * Paul Vixie, 1996. |
8912421c LC |
90 | */ |
91 | const char * | |
92 | inet_ntop (int af, const void *restrict src, | |
1cd4fffc | 93 | char *restrict dst, socklen_t cnt) |
8912421c LC |
94 | { |
95 | switch (af) | |
96 | { | |
35428fb6 | 97 | # if HAVE_IPV4 |
8912421c LC |
98 | case AF_INET: |
99 | return (inet_ntop4 (src, dst, cnt)); | |
35428fb6 | 100 | # endif |
8912421c | 101 | |
35428fb6 | 102 | # if HAVE_IPV6 |
8912421c LC |
103 | case AF_INET6: |
104 | return (inet_ntop6 (src, dst, cnt)); | |
35428fb6 | 105 | # endif |
8912421c LC |
106 | |
107 | default: | |
108 | errno = EAFNOSUPPORT; | |
109 | return (NULL); | |
110 | } | |
111 | /* NOTREACHED */ | |
112 | } | |
113 | ||
114 | /* const char * | |
115 | * inet_ntop4(src, dst, size) | |
1cd4fffc | 116 | * format an IPv4 address |
8912421c | 117 | * return: |
f0007cad | 118 | * 'dst' (as a const) |
8912421c | 119 | * notes: |
1cd4fffc LC |
120 | * (1) uses no statics |
121 | * (2) takes a u_char* not an in_addr as input | |
8912421c | 122 | * author: |
1cd4fffc | 123 | * Paul Vixie, 1996. |
8912421c LC |
124 | */ |
125 | static const char * | |
126 | inet_ntop4 (const unsigned char *src, char *dst, socklen_t size) | |
127 | { | |
128 | char tmp[sizeof "255.255.255.255"]; | |
129 | int len; | |
130 | ||
131 | len = sprintf (tmp, "%u.%u.%u.%u", src[0], src[1], src[2], src[3]); | |
132 | if (len < 0) | |
133 | return NULL; | |
134 | ||
135 | if (len > size) | |
136 | { | |
137 | errno = ENOSPC; | |
138 | return NULL; | |
139 | } | |
140 | ||
141 | return strcpy (dst, tmp); | |
142 | } | |
143 | ||
35428fb6 | 144 | # if HAVE_IPV6 |
8912421c LC |
145 | |
146 | /* const char * | |
147 | * inet_ntop6(src, dst, size) | |
1cd4fffc | 148 | * convert IPv6 binary address into presentation (printable) format |
8912421c | 149 | * author: |
1cd4fffc | 150 | * Paul Vixie, 1996. |
8912421c LC |
151 | */ |
152 | static const char * | |
153 | inet_ntop6 (const unsigned char *src, char *dst, socklen_t size) | |
154 | { | |
155 | /* | |
156 | * Note that int32_t and int16_t need only be "at least" large enough | |
157 | * to contain a value of the specified size. On some systems, like | |
158 | * Crays, there is no such thing as an integer variable with 16 bits. | |
159 | * Keep this in mind if you think this function should have been coded | |
160 | * to use pointer overlays. All the world's not a VAX. | |
161 | */ | |
162 | char tmp[sizeof "ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255"], *tp; | |
163 | struct | |
164 | { | |
165 | int base, len; | |
166 | } best, cur; | |
167 | unsigned int words[NS_IN6ADDRSZ / NS_INT16SZ]; | |
168 | int i; | |
169 | ||
170 | /* | |
171 | * Preprocess: | |
172 | * Copy the input (bytewise) array into a wordwise array. | |
173 | * Find the longest run of 0x00's in src[] for :: shorthanding. | |
174 | */ | |
175 | memset (words, '\0', sizeof words); | |
176 | for (i = 0; i < NS_IN6ADDRSZ; i += 2) | |
177 | words[i / 2] = (src[i] << 8) | src[i + 1]; | |
178 | best.base = -1; | |
179 | cur.base = -1; | |
f0007cad LC |
180 | IF_LINT(best.len = 0); |
181 | IF_LINT(cur.len = 0); | |
8912421c LC |
182 | for (i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); i++) |
183 | { | |
184 | if (words[i] == 0) | |
1cd4fffc LC |
185 | { |
186 | if (cur.base == -1) | |
187 | cur.base = i, cur.len = 1; | |
188 | else | |
189 | cur.len++; | |
190 | } | |
8912421c | 191 | else |
1cd4fffc LC |
192 | { |
193 | if (cur.base != -1) | |
194 | { | |
195 | if (best.base == -1 || cur.len > best.len) | |
196 | best = cur; | |
197 | cur.base = -1; | |
198 | } | |
199 | } | |
8912421c LC |
200 | } |
201 | if (cur.base != -1) | |
202 | { | |
203 | if (best.base == -1 || cur.len > best.len) | |
1cd4fffc | 204 | best = cur; |
8912421c LC |
205 | } |
206 | if (best.base != -1 && best.len < 2) | |
207 | best.base = -1; | |
208 | ||
209 | /* | |
210 | * Format the result. | |
211 | */ | |
212 | tp = tmp; | |
213 | for (i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); i++) | |
214 | { | |
215 | /* Are we inside the best run of 0x00's? */ | |
216 | if (best.base != -1 && i >= best.base && i < (best.base + best.len)) | |
1cd4fffc LC |
217 | { |
218 | if (i == best.base) | |
219 | *tp++ = ':'; | |
220 | continue; | |
221 | } | |
8912421c LC |
222 | /* Are we following an initial run of 0x00s or any real hex? */ |
223 | if (i != 0) | |
1cd4fffc | 224 | *tp++ = ':'; |
8912421c LC |
225 | /* Is this address an encapsulated IPv4? */ |
226 | if (i == 6 && best.base == 0 && | |
1cd4fffc LC |
227 | (best.len == 6 || (best.len == 5 && words[5] == 0xffff))) |
228 | { | |
229 | if (!inet_ntop4 (src + 12, tp, sizeof tmp - (tp - tmp))) | |
230 | return (NULL); | |
231 | tp += strlen (tp); | |
232 | break; | |
233 | } | |
8912421c | 234 | { |
1cd4fffc LC |
235 | int len = sprintf (tp, "%x", words[i]); |
236 | if (len < 0) | |
237 | return NULL; | |
238 | tp += len; | |
8912421c LC |
239 | } |
240 | } | |
241 | /* Was it a trailing run of 0x00's? */ | |
242 | if (best.base != -1 && (best.base + best.len) == | |
243 | (NS_IN6ADDRSZ / NS_INT16SZ)) | |
244 | *tp++ = ':'; | |
245 | *tp++ = '\0'; | |
246 | ||
247 | /* | |
248 | * Check for overflow, copy, and we're done. | |
249 | */ | |
250 | if ((socklen_t) (tp - tmp) > size) | |
251 | { | |
252 | errno = ENOSPC; | |
253 | return NULL; | |
254 | } | |
255 | ||
256 | return strcpy (dst, tmp); | |
257 | } | |
258 | ||
35428fb6 LC |
259 | # endif |
260 | ||
8912421c | 261 | #endif |