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.
20 #include "system/network.h"
23 #define NS_IN6ADDRSZ 16
26 * WARNING: Don't even consider trying to compile this on a system where
27 * sizeof(int) < 4. sizeof(int) > 4 is fine; all the world's not a VAX.
30 static const char *inet_ntop4(const unsigned char *src, char *dst,
34 static const char *inet_ntop6(const unsigned char *src, char *dst,
39 * isc_net_ntop(af, src, dst, size)
40 * convert a network format address to presentation format.
42 * pointer to presentation format address (`dst'), or NULL (see errno).
47 rep_inet_ntop(int af, const void *src, char *dst, socklen_t size)
51 return (inet_ntop4(src, dst, size));
54 return (inet_ntop6(src, dst, size));
64 * inet_ntop4(src, dst, size)
65 * format an IPv4 address
70 * (2) takes a unsigned char* not an in_addr as input
75 inet_ntop4(const unsigned char *src, char *dst, socklen_t size)
77 static const char *fmt = "%u.%u.%u.%u";
78 char tmp[sizeof "255.255.255.255"];
81 len = snprintf(tmp, sizeof tmp, fmt, src[0], src[1], src[2], src[3]);
86 memcpy(dst, tmp, len + 1);
92 * isc_inet_ntop6(src, dst, size)
93 * convert IPv6 binary address into presentation (printable) format
99 inet_ntop6(const unsigned char *src, char *dst, socklen_t size)
102 * Note that int32_t and int16_t need only be "at least" large enough
103 * to contain a value of the specified size. On some systems, like
104 * Crays, there is no such thing as an integer variable with 16 bits.
105 * Keep this in mind if you think this function should have been coded
106 * to use pointer overlays. All the world's not a VAX.
108 char tmp[sizeof "ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255"], *tp;
109 struct { int base, len; } best, cur;
110 unsigned int words[NS_IN6ADDRSZ / NS_INT16SZ];
115 * Copy the input (bytewise) array into a wordwise array.
116 * Find the longest run of 0x00's in src[] for :: shorthanding.
118 memset(words, '\0', sizeof words);
119 for (i = 0; i < NS_IN6ADDRSZ; i++)
120 words[i / 2] |= (src[i] << ((1 - (i % 2)) << 3));
125 for (i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); i++) {
128 cur.base = i, cur.len = 1;
132 if (cur.base != -1) {
133 if (best.base == -1 || cur.len > best.len)
139 if (cur.base != -1) {
140 if (best.base == -1 || cur.len > best.len)
143 if (best.base != -1 && best.len < 2)
150 for (i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); i++) {
151 /* Are we inside the best run of 0x00's? */
152 if (best.base != -1 && i >= best.base &&
153 i < (best.base + best.len)) {
158 /* Are we following an initial run of 0x00s or any real hex? */
161 /* Is this address an encapsulated IPv4? */
162 if (i == 6 && best.base == 0 &&
163 (best.len == 6 || (best.len == 5 && words[5] == 0xffff))) {
164 if (!inet_ntop4(src+12, tp, sizeof tmp - (tp - tmp)))
169 inc = snprintf(tp, 5, "%x", words[i]);
175 /* Was it a trailing run of 0x00's? */
176 if (best.base != -1 && (best.base + best.len) ==
177 (NS_IN6ADDRSZ / NS_INT16SZ))
182 * Check for overflow, copy, and we're done.
184 if ((size_t)(tp - tmp) > size) {
188 memcpy(dst, tmp, tp - tmp);
191 #endif /* AF_INET6 */