2 * Copyright (C) 2004 Internet Systems Consortium, Inc. ("ISC")
3 * Copyright (C) 1996-2001 Internet Software Consortium.
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.
9 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
10 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
11 * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
12 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
13 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
14 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
15 * PERFORMANCE OF THIS SOFTWARE.
18 #if defined(LIBC_SCCS) && !defined(lint)
20 "$Id: lwinetntop.c,v 1.9.2.1 2004/03/09 06:12:34 marka Exp $";
21 #endif /* LIBC_SCCS and not lint */
29 #include <lwres/net.h>
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 * lwres_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 lwres_net_ntop(int af, const void *src, char *dst, size_t size) {
59 return (inet_ntop4(src, dst, size));
62 return (inet_ntop6(src, dst, size));
72 * inet_ntop4(src, dst, size)
73 * format an IPv4 address
78 * (2) takes a unsigned char* not an in_addr as input
83 inet_ntop4(const unsigned char *src, char *dst, size_t size) {
84 static const char fmt[] = "%u.%u.%u.%u";
85 char tmp[sizeof "255.255.255.255"];
87 if ((size_t)sprintf(tmp, fmt, src[0], src[1], src[2], src[3]) >= size)
98 * inet_ntop6(src, dst, size)
99 * convert IPv6 binary address into presentation (printable) format
105 inet_ntop6(const unsigned char *src, char *dst, size_t size) {
107 * Note that int32_t and int16_t need only be "at least" large enough
108 * to contain a value of the specified size. On some systems, like
109 * Crays, there is no such thing as an integer variable with 16 bits.
110 * Keep this in mind if you think this function should have been coded
111 * to use pointer overlays. All the world's not a VAX.
113 char tmp[sizeof "ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255"], *tp;
114 struct { int base, len; } best, cur;
115 unsigned int words[NS_IN6ADDRSZ / NS_INT16SZ];
120 * Copy the input (bytewise) array into a wordwise array.
121 * Find the longest run of 0x00's in src[] for :: shorthanding.
123 memset(words, '\0', sizeof words);
124 for (i = 0; i < NS_IN6ADDRSZ; i++)
125 words[i / 2] |= (src[i] << ((1 - (i % 2)) << 3));
128 for (i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); i++) {
131 cur.base = i, cur.len = 1;
135 if (cur.base != -1) {
136 if (best.base == -1 || cur.len > best.len)
142 if (cur.base != -1) {
143 if (best.base == -1 || cur.len > best.len)
146 if (best.base != -1 && best.len < 2)
153 for (i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); i++) {
154 /* Are we inside the best run of 0x00's? */
155 if (best.base != -1 && i >= best.base &&
156 i < (best.base + best.len)) {
161 /* Are we following an initial run of 0x00s or any real hex? */
164 /* Is this address an encapsulated IPv4? */
165 if (i == 6 && best.base == 0 &&
166 (best.len == 6 || (best.len == 5 && words[5] == 0xffff))) {
167 if (!inet_ntop4(src+12, tp,
168 sizeof tmp - (tp - tmp)))
173 tp += sprintf(tp, "%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) {
191 #endif /* AF_INET6 */