Commit | Line | Data |
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8f694072 MP |
1 | /* |
2 | * Copyright (C) 1996-2001 Internet Software Consortium. | |
3 | * | |
4 | * Permission to use, copy, modify, and distribute this software for any | |
5 | * purpose with or without fee is hereby granted, provided that the above | |
6 | * copyright notice and this permission notice appear in all copies. | |
7 | * | |
8 | * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM | |
9 | * DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL | |
10 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL | |
11 | * INTERNET SOFTWARE CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, | |
12 | * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING | |
13 | * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, | |
14 | * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION | |
15 | * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. | |
16 | */ | |
17 | ||
18 | #if defined(LIBC_SCCS) && !defined(lint) | |
19 | static char rcsid[] = | |
20 | "$Id$"; | |
21 | #endif /* LIBC_SCCS and not lint */ | |
22 | ||
23 | #include <config.h> | |
24 | ||
25 | #include <errno.h> | |
26 | #include <stdio.h> | |
27 | #include <string.h> | |
28 | ||
29 | #include <isc/net.h> | |
30 | ||
31 | #define NS_INT16SZ 2 | |
32 | #define NS_IN6ADDRSZ 16 | |
33 | ||
34 | /* | |
35 | * WARNING: Don't even consider trying to compile this on a system where | |
36 | * sizeof(int) < 4. sizeof(int) > 4 is fine; all the world's not a VAX. | |
37 | */ | |
38 | ||
39 | static const char *inet_ntop4(const unsigned char *src, char *dst, | |
40 | size_t size); | |
41 | ||
42 | #ifdef AF_INET6 | |
43 | static const char *inet_ntop6(const unsigned char *src, char *dst, | |
44 | size_t size); | |
45 | #endif | |
46 | ||
47 | /* char * | |
48 | * isc_net_ntop(af, src, dst, size) | |
49 | * convert a network format address to presentation format. | |
50 | * return: | |
51 | * pointer to presentation format address (`dst'), or NULL (see errno). | |
52 | * author: | |
53 | * Paul Vixie, 1996. | |
54 | */ | |
55 | const char * | |
56 | isc_net_ntop(int af, const void *src, char *dst, size_t size) | |
57 | { | |
58 | switch (af) { | |
59 | case AF_INET: | |
60 | return (inet_ntop4(src, dst, size)); | |
61 | #ifdef AF_INET6 | |
62 | case AF_INET6: | |
63 | return (inet_ntop6(src, dst, size)); | |
64 | #endif | |
65 | default: | |
66 | errno = EAFNOSUPPORT; | |
67 | return (NULL); | |
68 | } | |
69 | /* NOTREACHED */ | |
70 | } | |
71 | ||
72 | /* const char * | |
73 | * inet_ntop4(src, dst, size) | |
74 | * format an IPv4 address | |
75 | * return: | |
76 | * `dst' (as a const) | |
77 | * notes: | |
78 | * (1) uses no statics | |
79 | * (2) takes a unsigned char* not an in_addr as input | |
80 | * author: | |
81 | * Paul Vixie, 1996. | |
82 | */ | |
83 | static const char * | |
84 | inet_ntop4(const unsigned char *src, char *dst, size_t size) | |
85 | { | |
86 | static const char *fmt = "%u.%u.%u.%u"; | |
87 | char tmp[sizeof "255.255.255.255"]; | |
88 | ||
89 | if ((size_t)sprintf(tmp, fmt, src[0], src[1], src[2], src[3]) >= size) | |
90 | { | |
91 | errno = ENOSPC; | |
92 | return (NULL); | |
93 | } | |
94 | strcpy(dst, tmp); | |
95 | ||
96 | return (dst); | |
97 | } | |
98 | ||
99 | /* const char * | |
100 | * isc_inet_ntop6(src, dst, size) | |
101 | * convert IPv6 binary address into presentation (printable) format | |
102 | * author: | |
103 | * Paul Vixie, 1996. | |
104 | */ | |
105 | #ifdef AF_INET6 | |
106 | static const char * | |
107 | inet_ntop6(const unsigned char *src, char *dst, size_t size) | |
108 | { | |
109 | /* | |
110 | * Note that int32_t and int16_t need only be "at least" large enough | |
111 | * to contain a value of the specified size. On some systems, like | |
112 | * Crays, there is no such thing as an integer variable with 16 bits. | |
113 | * Keep this in mind if you think this function should have been coded | |
114 | * to use pointer overlays. All the world's not a VAX. | |
115 | */ | |
116 | char tmp[sizeof "ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255"], *tp; | |
117 | struct { int base, len; } best, cur; | |
118 | unsigned int words[NS_IN6ADDRSZ / NS_INT16SZ]; | |
119 | int i; | |
120 | ||
121 | /* | |
122 | * Preprocess: | |
123 | * Copy the input (bytewise) array into a wordwise array. | |
124 | * Find the longest run of 0x00's in src[] for :: shorthanding. | |
125 | */ | |
126 | memset(words, '\0', sizeof words); | |
127 | for (i = 0; i < NS_IN6ADDRSZ; i++) | |
128 | words[i / 2] |= (src[i] << ((1 - (i % 2)) << 3)); | |
129 | best.base = -1; | |
130 | cur.base = -1; | |
131 | for (i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); i++) { | |
132 | if (words[i] == 0) { | |
133 | if (cur.base == -1) | |
134 | cur.base = i, cur.len = 1; | |
135 | else | |
136 | cur.len++; | |
137 | } else { | |
138 | if (cur.base != -1) { | |
139 | if (best.base == -1 || cur.len > best.len) | |
140 | best = cur; | |
141 | cur.base = -1; | |
142 | } | |
143 | } | |
144 | } | |
145 | if (cur.base != -1) { | |
146 | if (best.base == -1 || cur.len > best.len) | |
147 | best = cur; | |
148 | } | |
149 | if (best.base != -1 && best.len < 2) | |
150 | best.base = -1; | |
151 | ||
152 | /* | |
153 | * Format the result. | |
154 | */ | |
155 | tp = tmp; | |
156 | for (i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); i++) { | |
157 | /* Are we inside the best run of 0x00's? */ | |
158 | if (best.base != -1 && i >= best.base && | |
159 | i < (best.base + best.len)) { | |
160 | if (i == best.base) | |
161 | *tp++ = ':'; | |
162 | continue; | |
163 | } | |
164 | /* Are we following an initial run of 0x00s or any real hex? */ | |
165 | if (i != 0) | |
166 | *tp++ = ':'; | |
167 | /* Is this address an encapsulated IPv4? */ | |
168 | if (i == 6 && best.base == 0 && | |
169 | (best.len == 6 || (best.len == 5 && words[5] == 0xffff))) { | |
170 | if (!inet_ntop4(src+12, tp, | |
171 | sizeof tmp - (tp - tmp))) | |
172 | return (NULL); | |
173 | tp += strlen(tp); | |
174 | break; | |
175 | } | |
176 | tp += sprintf(tp, "%x", words[i]); | |
177 | } | |
178 | /* Was it a trailing run of 0x00's? */ | |
179 | if (best.base != -1 && (best.base + best.len) == | |
180 | (NS_IN6ADDRSZ / NS_INT16SZ)) | |
181 | *tp++ = ':'; | |
182 | *tp++ = '\0'; | |
183 | ||
184 | /* | |
185 | * Check for overflow, copy, and we're done. | |
186 | */ | |
187 | if ((size_t)(tp - tmp) > size) { | |
188 | errno = ENOSPC; | |
189 | return (NULL); | |
190 | } | |
191 | strcpy(dst, tmp); | |
192 | return (dst); | |
193 | } | |
194 | #endif /* AF_INET6 */ |