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68b36828 | 1 | /* $OpenBSD: inet_ntop.c,v 1.7 2005/08/06 20:30:03 espie Exp $ */ |
a704dd54 | 2 | |
3 | /* Copyright (c) 1996 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 INTERNET SOFTWARE CONSORTIUM DISCLAIMS | |
10 | * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES | |
11 | * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE | |
12 | * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL | |
13 | * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR | |
14 | * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS | |
15 | * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS | |
16 | * SOFTWARE. | |
17 | */ | |
18 | ||
f6d4fb87 | 19 | /* OPENBSD ORIGINAL: lib/libc/net/inet_ntop.c */ |
20 | ||
17962c40 | 21 | #include "includes.h" |
a704dd54 | 22 | |
23 | #ifndef HAVE_INET_NTOP | |
24 | ||
a704dd54 | 25 | #include <sys/param.h> |
26 | #include <sys/types.h> | |
27 | #include <sys/socket.h> | |
a704dd54 | 28 | #include <netinet/in.h> |
29 | #include <arpa/inet.h> | |
a704dd54 | 30 | #include <arpa/nameser.h> |
a704dd54 | 31 | #include <string.h> |
32 | #include <errno.h> | |
33 | #include <stdio.h> | |
34 | ||
35 | #ifndef IN6ADDRSZ | |
36 | #define IN6ADDRSZ 16 /* IPv6 T_AAAA */ | |
37 | #endif | |
38 | ||
39 | #ifndef INT16SZ | |
40 | #define INT16SZ 2 /* for systems without 16-bit ints */ | |
41 | #endif | |
42 | ||
43 | /* | |
44 | * WARNING: Don't even consider trying to compile this on a system where | |
45 | * sizeof(int) < 4. sizeof(int) > 4 is fine; all the world's not a VAX. | |
46 | */ | |
47 | ||
ac8802eb | 48 | static const char *inet_ntop4(const u_char *src, char *dst, size_t size); |
49 | static const char *inet_ntop6(const u_char *src, char *dst, size_t size); | |
a704dd54 | 50 | |
51 | /* char * | |
52 | * inet_ntop(af, src, dst, size) | |
53 | * convert a network format address to presentation format. | |
54 | * return: | |
55 | * pointer to presentation format address (`dst'), or NULL (see errno). | |
56 | * author: | |
57 | * Paul Vixie, 1996. | |
58 | */ | |
59 | const char * | |
68b36828 | 60 | inet_ntop(int af, const void *src, char *dst, size_t size) |
a704dd54 | 61 | { |
62 | switch (af) { | |
63 | case AF_INET: | |
64 | return (inet_ntop4(src, dst, size)); | |
65 | case AF_INET6: | |
66 | return (inet_ntop6(src, dst, size)); | |
67 | default: | |
68 | errno = EAFNOSUPPORT; | |
69 | return (NULL); | |
70 | } | |
71 | /* NOTREACHED */ | |
72 | } | |
73 | ||
74 | /* const char * | |
75 | * inet_ntop4(src, dst, size) | |
76 | * format an IPv4 address, more or less like inet_ntoa() | |
77 | * return: | |
78 | * `dst' (as a const) | |
79 | * notes: | |
80 | * (1) uses no statics | |
81 | * (2) takes a u_char* not an in_addr as input | |
82 | * author: | |
83 | * Paul Vixie, 1996. | |
84 | */ | |
85 | static const char * | |
68b36828 | 86 | inet_ntop4(const u_char *src, char *dst, size_t size) |
a704dd54 | 87 | { |
88 | static const char fmt[] = "%u.%u.%u.%u"; | |
89 | char tmp[sizeof "255.255.255.255"]; | |
ac8802eb | 90 | int l; |
a704dd54 | 91 | |
ac8802eb | 92 | l = snprintf(tmp, size, fmt, src[0], src[1], src[2], src[3]); |
93 | if (l <= 0 || l >= size) { | |
a704dd54 | 94 | errno = ENOSPC; |
95 | return (NULL); | |
96 | } | |
ac8802eb | 97 | strlcpy(dst, tmp, size); |
a704dd54 | 98 | return (dst); |
99 | } | |
100 | ||
101 | /* const char * | |
102 | * inet_ntop6(src, dst, size) | |
103 | * convert IPv6 binary address into presentation (printable) format | |
104 | * author: | |
105 | * Paul Vixie, 1996. | |
106 | */ | |
107 | static const char * | |
68b36828 | 108 | inet_ntop6(const u_char *src, char *dst, size_t size) |
a704dd54 | 109 | { |
110 | /* | |
111 | * Note that int32_t and int16_t need only be "at least" large enough | |
112 | * to contain a value of the specified size. On some systems, like | |
113 | * Crays, there is no such thing as an integer variable with 16 bits. | |
114 | * Keep this in mind if you think this function should have been coded | |
115 | * to use pointer overlays. All the world's not a VAX. | |
116 | */ | |
ac8802eb | 117 | char tmp[sizeof "ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255"]; |
118 | char *tp, *ep; | |
a704dd54 | 119 | struct { int base, len; } best, cur; |
120 | u_int words[IN6ADDRSZ / INT16SZ]; | |
121 | int i; | |
ac8802eb | 122 | int advance; |
a704dd54 | 123 | |
124 | /* | |
125 | * Preprocess: | |
126 | * Copy the input (bytewise) array into a wordwise array. | |
127 | * Find the longest run of 0x00's in src[] for :: shorthanding. | |
128 | */ | |
129 | memset(words, '\0', sizeof words); | |
130 | for (i = 0; i < IN6ADDRSZ; i++) | |
131 | words[i / 2] |= (src[i] << ((1 - (i % 2)) << 3)); | |
132 | best.base = -1; | |
133 | cur.base = -1; | |
134 | for (i = 0; i < (IN6ADDRSZ / INT16SZ); i++) { | |
135 | if (words[i] == 0) { | |
136 | if (cur.base == -1) | |
137 | cur.base = i, cur.len = 1; | |
138 | else | |
139 | cur.len++; | |
140 | } else { | |
141 | if (cur.base != -1) { | |
142 | if (best.base == -1 || cur.len > best.len) | |
143 | best = cur; | |
144 | cur.base = -1; | |
145 | } | |
146 | } | |
147 | } | |
148 | if (cur.base != -1) { | |
149 | if (best.base == -1 || cur.len > best.len) | |
150 | best = cur; | |
151 | } | |
152 | if (best.base != -1 && best.len < 2) | |
153 | best.base = -1; | |
154 | ||
155 | /* | |
156 | * Format the result. | |
157 | */ | |
158 | tp = tmp; | |
ac8802eb | 159 | ep = tmp + sizeof(tmp); |
160 | for (i = 0; i < (IN6ADDRSZ / INT16SZ) && tp < ep; i++) { | |
a704dd54 | 161 | /* Are we inside the best run of 0x00's? */ |
162 | if (best.base != -1 && i >= best.base && | |
163 | i < (best.base + best.len)) { | |
ac8802eb | 164 | if (i == best.base) { |
165 | if (tp + 1 >= ep) | |
166 | return (NULL); | |
a704dd54 | 167 | *tp++ = ':'; |
ac8802eb | 168 | } |
a704dd54 | 169 | continue; |
170 | } | |
171 | /* Are we following an initial run of 0x00s or any real hex? */ | |
ac8802eb | 172 | if (i != 0) { |
173 | if (tp + 1 >= ep) | |
174 | return (NULL); | |
a704dd54 | 175 | *tp++ = ':'; |
ac8802eb | 176 | } |
a704dd54 | 177 | /* Is this address an encapsulated IPv4? */ |
178 | if (i == 6 && best.base == 0 && | |
179 | (best.len == 6 || (best.len == 5 && words[5] == 0xffff))) { | |
ac8802eb | 180 | if (!inet_ntop4(src+12, tp, (size_t)(ep - tp))) |
a704dd54 | 181 | return (NULL); |
182 | tp += strlen(tp); | |
183 | break; | |
184 | } | |
ac8802eb | 185 | advance = snprintf(tp, ep - tp, "%x", words[i]); |
186 | if (advance <= 0 || advance >= ep - tp) | |
187 | return (NULL); | |
188 | tp += advance; | |
a704dd54 | 189 | } |
190 | /* Was it a trailing run of 0x00's? */ | |
ac8802eb | 191 | if (best.base != -1 && (best.base + best.len) == (IN6ADDRSZ / INT16SZ)) { |
192 | if (tp + 1 >= ep) | |
193 | return (NULL); | |
a704dd54 | 194 | *tp++ = ':'; |
ac8802eb | 195 | } |
196 | if (tp + 1 >= ep) | |
197 | return (NULL); | |
a704dd54 | 198 | *tp++ = '\0'; |
199 | ||
200 | /* | |
201 | * Check for overflow, copy, and we're done. | |
202 | */ | |
203 | if ((size_t)(tp - tmp) > size) { | |
204 | errno = ENOSPC; | |
205 | return (NULL); | |
206 | } | |
ac8802eb | 207 | strlcpy(dst, tmp, size); |
a704dd54 | 208 | return (dst); |
209 | } | |
210 | ||
211 | #endif /* !HAVE_INET_NTOP */ |