Damien Miller | 71eb0c1 | 2002-09-11 10:29:11 +1000 | [diff] [blame] | 1 | /* $OpenBSD: inet_ntop.c,v 1.5 2002/08/23 16:27:31 itojun Exp $ */ |
Tim Rice | e991e3c | 2001-08-07 15:29:07 -0700 | [diff] [blame] | 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 | |
Ben Lindstrom | dd21fe9 | 2002-06-27 18:23:20 +0000 | [diff] [blame] | 19 | #include "includes.h" |
Tim Rice | e991e3c | 2001-08-07 15:29:07 -0700 | [diff] [blame] | 20 | |
| 21 | #ifndef HAVE_INET_NTOP |
| 22 | |
| 23 | #if defined(LIBC_SCCS) && !defined(lint) |
| 24 | #if 0 |
| 25 | static char rcsid[] = "$From: inet_ntop.c,v 8.7 1996/08/05 08:41:18 vixie Exp $"; |
| 26 | #else |
Damien Miller | 71eb0c1 | 2002-09-11 10:29:11 +1000 | [diff] [blame] | 27 | static char rcsid[] = "$OpenBSD: inet_ntop.c,v 1.5 2002/08/23 16:27:31 itojun Exp $"; |
Tim Rice | e991e3c | 2001-08-07 15:29:07 -0700 | [diff] [blame] | 28 | #endif |
| 29 | #endif /* LIBC_SCCS and not lint */ |
| 30 | |
| 31 | #include <sys/param.h> |
| 32 | #include <sys/types.h> |
| 33 | #include <sys/socket.h> |
| 34 | #include "openbsd-compat/fake-socket.h" |
| 35 | #include <netinet/in.h> |
| 36 | #include <arpa/inet.h> |
| 37 | #ifndef HAVE_CYGWIN |
| 38 | #include <arpa/nameser.h> |
| 39 | #endif |
| 40 | #include <string.h> |
| 41 | #include <errno.h> |
| 42 | #include <stdio.h> |
| 43 | |
| 44 | #ifndef IN6ADDRSZ |
| 45 | #define IN6ADDRSZ 16 /* IPv6 T_AAAA */ |
| 46 | #endif |
| 47 | |
| 48 | #ifndef INT16SZ |
| 49 | #define INT16SZ 2 /* for systems without 16-bit ints */ |
| 50 | #endif |
| 51 | |
| 52 | /* |
| 53 | * WARNING: Don't even consider trying to compile this on a system where |
| 54 | * sizeof(int) < 4. sizeof(int) > 4 is fine; all the world's not a VAX. |
| 55 | */ |
| 56 | |
Damien Miller | 71eb0c1 | 2002-09-11 10:29:11 +1000 | [diff] [blame] | 57 | static const char *inet_ntop4(const u_char *src, char *dst, size_t size); |
| 58 | static const char *inet_ntop6(const u_char *src, char *dst, size_t size); |
Tim Rice | e991e3c | 2001-08-07 15:29:07 -0700 | [diff] [blame] | 59 | |
| 60 | /* char * |
| 61 | * inet_ntop(af, src, dst, size) |
| 62 | * convert a network format address to presentation format. |
| 63 | * return: |
| 64 | * pointer to presentation format address (`dst'), or NULL (see errno). |
| 65 | * author: |
| 66 | * Paul Vixie, 1996. |
| 67 | */ |
| 68 | const char * |
| 69 | inet_ntop(af, src, dst, size) |
| 70 | int af; |
| 71 | const void *src; |
| 72 | char *dst; |
| 73 | size_t size; |
| 74 | { |
| 75 | switch (af) { |
| 76 | case AF_INET: |
| 77 | return (inet_ntop4(src, dst, size)); |
| 78 | case AF_INET6: |
| 79 | return (inet_ntop6(src, dst, size)); |
| 80 | default: |
| 81 | errno = EAFNOSUPPORT; |
| 82 | return (NULL); |
| 83 | } |
| 84 | /* NOTREACHED */ |
| 85 | } |
| 86 | |
| 87 | /* const char * |
| 88 | * inet_ntop4(src, dst, size) |
| 89 | * format an IPv4 address, more or less like inet_ntoa() |
| 90 | * return: |
| 91 | * `dst' (as a const) |
| 92 | * notes: |
| 93 | * (1) uses no statics |
| 94 | * (2) takes a u_char* not an in_addr as input |
| 95 | * author: |
| 96 | * Paul Vixie, 1996. |
| 97 | */ |
| 98 | static const char * |
| 99 | inet_ntop4(src, dst, size) |
| 100 | const u_char *src; |
| 101 | char *dst; |
| 102 | size_t size; |
| 103 | { |
| 104 | static const char fmt[] = "%u.%u.%u.%u"; |
| 105 | char tmp[sizeof "255.255.255.255"]; |
Damien Miller | 71eb0c1 | 2002-09-11 10:29:11 +1000 | [diff] [blame] | 106 | int l; |
Tim Rice | e991e3c | 2001-08-07 15:29:07 -0700 | [diff] [blame] | 107 | |
Damien Miller | 71eb0c1 | 2002-09-11 10:29:11 +1000 | [diff] [blame] | 108 | l = snprintf(tmp, size, fmt, src[0], src[1], src[2], src[3]); |
| 109 | if (l <= 0 || l >= size) { |
Tim Rice | e991e3c | 2001-08-07 15:29:07 -0700 | [diff] [blame] | 110 | errno = ENOSPC; |
| 111 | return (NULL); |
| 112 | } |
Damien Miller | 71eb0c1 | 2002-09-11 10:29:11 +1000 | [diff] [blame] | 113 | strlcpy(dst, tmp, size); |
Tim Rice | e991e3c | 2001-08-07 15:29:07 -0700 | [diff] [blame] | 114 | return (dst); |
| 115 | } |
| 116 | |
| 117 | /* const char * |
| 118 | * inet_ntop6(src, dst, size) |
| 119 | * convert IPv6 binary address into presentation (printable) format |
| 120 | * author: |
| 121 | * Paul Vixie, 1996. |
| 122 | */ |
| 123 | static const char * |
| 124 | inet_ntop6(src, dst, size) |
| 125 | const u_char *src; |
| 126 | char *dst; |
| 127 | size_t size; |
| 128 | { |
| 129 | /* |
| 130 | * Note that int32_t and int16_t need only be "at least" large enough |
| 131 | * to contain a value of the specified size. On some systems, like |
| 132 | * Crays, there is no such thing as an integer variable with 16 bits. |
| 133 | * Keep this in mind if you think this function should have been coded |
| 134 | * to use pointer overlays. All the world's not a VAX. |
| 135 | */ |
Damien Miller | 71eb0c1 | 2002-09-11 10:29:11 +1000 | [diff] [blame] | 136 | char tmp[sizeof "ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255"]; |
| 137 | char *tp, *ep; |
Tim Rice | e991e3c | 2001-08-07 15:29:07 -0700 | [diff] [blame] | 138 | struct { int base, len; } best, cur; |
| 139 | u_int words[IN6ADDRSZ / INT16SZ]; |
| 140 | int i; |
Damien Miller | 71eb0c1 | 2002-09-11 10:29:11 +1000 | [diff] [blame] | 141 | int advance; |
Tim Rice | e991e3c | 2001-08-07 15:29:07 -0700 | [diff] [blame] | 142 | |
| 143 | /* |
| 144 | * Preprocess: |
| 145 | * Copy the input (bytewise) array into a wordwise array. |
| 146 | * Find the longest run of 0x00's in src[] for :: shorthanding. |
| 147 | */ |
| 148 | memset(words, '\0', sizeof words); |
| 149 | for (i = 0; i < IN6ADDRSZ; i++) |
| 150 | words[i / 2] |= (src[i] << ((1 - (i % 2)) << 3)); |
| 151 | best.base = -1; |
| 152 | cur.base = -1; |
| 153 | for (i = 0; i < (IN6ADDRSZ / INT16SZ); i++) { |
| 154 | if (words[i] == 0) { |
| 155 | if (cur.base == -1) |
| 156 | cur.base = i, cur.len = 1; |
| 157 | else |
| 158 | cur.len++; |
| 159 | } else { |
| 160 | if (cur.base != -1) { |
| 161 | if (best.base == -1 || cur.len > best.len) |
| 162 | best = cur; |
| 163 | cur.base = -1; |
| 164 | } |
| 165 | } |
| 166 | } |
| 167 | if (cur.base != -1) { |
| 168 | if (best.base == -1 || cur.len > best.len) |
| 169 | best = cur; |
| 170 | } |
| 171 | if (best.base != -1 && best.len < 2) |
| 172 | best.base = -1; |
| 173 | |
| 174 | /* |
| 175 | * Format the result. |
| 176 | */ |
| 177 | tp = tmp; |
Damien Miller | 71eb0c1 | 2002-09-11 10:29:11 +1000 | [diff] [blame] | 178 | ep = tmp + sizeof(tmp); |
| 179 | for (i = 0; i < (IN6ADDRSZ / INT16SZ) && tp < ep; i++) { |
Tim Rice | e991e3c | 2001-08-07 15:29:07 -0700 | [diff] [blame] | 180 | /* Are we inside the best run of 0x00's? */ |
| 181 | if (best.base != -1 && i >= best.base && |
| 182 | i < (best.base + best.len)) { |
Damien Miller | 71eb0c1 | 2002-09-11 10:29:11 +1000 | [diff] [blame] | 183 | if (i == best.base) { |
| 184 | if (tp + 1 >= ep) |
| 185 | return (NULL); |
Tim Rice | e991e3c | 2001-08-07 15:29:07 -0700 | [diff] [blame] | 186 | *tp++ = ':'; |
Damien Miller | 71eb0c1 | 2002-09-11 10:29:11 +1000 | [diff] [blame] | 187 | } |
Tim Rice | e991e3c | 2001-08-07 15:29:07 -0700 | [diff] [blame] | 188 | continue; |
| 189 | } |
| 190 | /* Are we following an initial run of 0x00s or any real hex? */ |
Damien Miller | 71eb0c1 | 2002-09-11 10:29:11 +1000 | [diff] [blame] | 191 | if (i != 0) { |
| 192 | if (tp + 1 >= ep) |
| 193 | return (NULL); |
Tim Rice | e991e3c | 2001-08-07 15:29:07 -0700 | [diff] [blame] | 194 | *tp++ = ':'; |
Damien Miller | 71eb0c1 | 2002-09-11 10:29:11 +1000 | [diff] [blame] | 195 | } |
Tim Rice | e991e3c | 2001-08-07 15:29:07 -0700 | [diff] [blame] | 196 | /* Is this address an encapsulated IPv4? */ |
| 197 | if (i == 6 && best.base == 0 && |
| 198 | (best.len == 6 || (best.len == 5 && words[5] == 0xffff))) { |
Damien Miller | 71eb0c1 | 2002-09-11 10:29:11 +1000 | [diff] [blame] | 199 | if (!inet_ntop4(src+12, tp, (size_t)(ep - tp))) |
Tim Rice | e991e3c | 2001-08-07 15:29:07 -0700 | [diff] [blame] | 200 | return (NULL); |
| 201 | tp += strlen(tp); |
| 202 | break; |
| 203 | } |
Damien Miller | 71eb0c1 | 2002-09-11 10:29:11 +1000 | [diff] [blame] | 204 | advance = snprintf(tp, ep - tp, "%x", words[i]); |
| 205 | if (advance <= 0 || advance >= ep - tp) |
| 206 | return (NULL); |
| 207 | tp += advance; |
Tim Rice | e991e3c | 2001-08-07 15:29:07 -0700 | [diff] [blame] | 208 | } |
| 209 | /* Was it a trailing run of 0x00's? */ |
Damien Miller | 71eb0c1 | 2002-09-11 10:29:11 +1000 | [diff] [blame] | 210 | if (best.base != -1 && (best.base + best.len) == (IN6ADDRSZ / INT16SZ)) { |
| 211 | if (tp + 1 >= ep) |
| 212 | return (NULL); |
Tim Rice | e991e3c | 2001-08-07 15:29:07 -0700 | [diff] [blame] | 213 | *tp++ = ':'; |
Damien Miller | 71eb0c1 | 2002-09-11 10:29:11 +1000 | [diff] [blame] | 214 | } |
| 215 | if (tp + 1 >= ep) |
| 216 | return (NULL); |
Tim Rice | e991e3c | 2001-08-07 15:29:07 -0700 | [diff] [blame] | 217 | *tp++ = '\0'; |
| 218 | |
| 219 | /* |
| 220 | * Check for overflow, copy, and we're done. |
| 221 | */ |
| 222 | if ((size_t)(tp - tmp) > size) { |
| 223 | errno = ENOSPC; |
| 224 | return (NULL); |
| 225 | } |
Damien Miller | 71eb0c1 | 2002-09-11 10:29:11 +1000 | [diff] [blame] | 226 | strlcpy(dst, tmp, size); |
Tim Rice | e991e3c | 2001-08-07 15:29:07 -0700 | [diff] [blame] | 227 | return (dst); |
| 228 | } |
| 229 | |
| 230 | #endif /* !HAVE_INET_NTOP */ |