2 * Copyright (C) 1996-2001 Internet Software Consortium.
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.
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.
18 #if defined(LIBC_SCCS) && !defined(lint)
21 #endif /* LIBC_SCCS and not lint */
32 #define NS_IN6ADDRSZ 16
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.
39 static const char *inet_ntop4(const unsigned char *src, char *dst,
43 static const char *inet_ntop6(const unsigned char *src, char *dst,
48 * isc_net_ntop(af, src, dst, size)
49 * convert a network format address to presentation format.
51 * pointer to presentation format address (`dst'), or NULL (see errno).
56 isc_net_ntop(int af, const void *src, char *dst, size_t size)
60 return (inet_ntop4(src, dst, size));
63 return (inet_ntop6(src, dst, size));
73 * inet_ntop4(src, dst, size)
74 * format an IPv4 address
79 * (2) takes a unsigned char* not an in_addr as input
84 inet_ntop4(const unsigned char *src, char *dst, size_t size)
86 static const char *fmt = "%u.%u.%u.%u";
87 char tmp[sizeof "255.255.255.255"];
89 if ((size_t)sprintf(tmp, fmt, src[0], src[1], src[2], src[3]) >= size)
100 * isc_inet_ntop6(src, dst, size)
101 * convert IPv6 binary address into presentation (printable) format
107 inet_ntop6(const unsigned char *src, char *dst, size_t size)
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.
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];
123 * Copy the input (bytewise) array into a wordwise array.
124 * Find the longest run of 0x00's in src[] for :: shorthanding.
126 memset(words, '\0', sizeof words);
127 for (i = 0; i < NS_IN6ADDRSZ; i++)
128 words[i / 2] |= (src[i] << ((1 - (i % 2)) << 3));
131 for (i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); i++) {
134 cur.base = i, cur.len = 1;
138 if (cur.base != -1) {
139 if (best.base == -1 || cur.len > best.len)
145 if (cur.base != -1) {
146 if (best.base == -1 || cur.len > best.len)
149 if (best.base != -1 && best.len < 2)
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)) {
164 /* Are we following an initial run of 0x00s or any real hex? */
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)))
176 tp += sprintf(tp, "%x", words[i]);
178 /* Was it a trailing run of 0x00's? */
179 if (best.base != -1 && (best.base + best.len) ==
180 (NS_IN6ADDRSZ / NS_INT16SZ))
185 * Check for overflow, copy, and we're done.
187 if ((size_t)(tp - tmp) > size) {
194 #endif /* AF_INET6 */