7 * Copyright (C) 1996-2001 Internet Software Consortium.
9 * Permission to use, copy, modify, and distribute this software for any
10 * purpose with or without fee is hereby granted, provided that the above
11 * copyright notice and this permission notice appear in all copies.
13 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM
14 * DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
16 * INTERNET SOFTWARE CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT,
17 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
18 * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
19 * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
20 * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
23 #ifndef HAVE_INET_NTOP
26 #define NS_IN6ADDRSZ 16
29 * WARNING: Don't even consider trying to compile this on a system where
30 * sizeof(int) < 4. sizeof(int) > 4 is fine; all the world's not a VAX.
35 * isc_net_ntop(af, src, dst, size)
36 * convert a network format address to presentation format.
38 * pointer to presentation format address (`dst'), or NULL (see errno).
43 inet_ntop(int af, const void *src, char *dst, size_t size) {
46 return(inet_ntop4(src, dst, size));
49 return(inet_ntop6(src, dst, size));
58 * inet_ntop4(src, dst, size)
59 * format an IPv4 address
64 * (2) takes a unsigned char* not an in_addr as input
69 inet_ntop4(const unsigned char *src, char *dst, size_t size) {
70 static const char *fmt = "%u.%u.%u.%u";
71 char tmp[sizeof "255.255.255.255"];
73 if ( (size_t)sprintf(tmp, fmt, src[0], src[1], src[2], src[3]) >= size ) {
82 * isc_inet_ntop6(src, dst, size)
83 * convert IPv6 binary address into presentation (printable) format
89 inet_ntop6(const unsigned char *src, char *dst, size_t size) {
91 * Note that int32_t and int16_t need only be "at least" large enough
92 * to contain a value of the specified size. On some systems, like
93 * Crays, there is no such thing as an integer variable with 16 bits.
94 * Keep this in mind if you think this function should have been coded
95 * to use pointer overlays. All the world's not a VAX.
97 char tmp[sizeof "ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255"], *tp;
101 unsigned int words[NS_IN6ADDRSZ / NS_INT16SZ];
106 * Copy the input (bytewise) array into a wordwise array.
107 * Find the longest run of 0x00's in src[] for :: shorthanding.
109 memset(words, '\0', sizeof words);
110 for ( i = 0; i < NS_IN6ADDRSZ; i++ )
111 words[i / 2] |= (src[i] << ((1 - (i % 2)) << 3));
114 for ( i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); i++ ) {
115 if ( words[i] == 0 ) {
116 if ( cur.base == -1 )
117 cur.base = i, cur.len = 1;
121 if ( cur.base != -1 ) {
122 if ( best.base == -1 || cur.len > best.len )
128 if ( cur.base != -1 ) {
129 if ( best.base == -1 || cur.len > best.len )
132 if ( best.base != -1 && best.len < 2 )
139 for ( i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); i++ ) {
140 /* Are we inside the best run of 0x00's? */
141 if ( best.base != -1 && i >= best.base &&
142 i < (best.base + best.len) ) {
143 if ( i == best.base )
147 /* Are we following an initial run of 0x00s or any real hex? */
150 /* Is this address an encapsulated IPv4? */
151 if ( i == 6 && best.base == 0 &&
152 (best.len == 6 || (best.len == 5 && words[5] == 0xffff)) ) {
153 if ( !inet_ntop4(src+12, tp,
154 sizeof tmp - (tp - tmp)) )
159 tp += sprintf(tp, "%x", words[i]);
161 /* Was it a trailing run of 0x00's? */
162 if ( best.base != -1 && (best.base + best.len) ==
163 (NS_IN6ADDRSZ / NS_INT16SZ) )
168 * Check for overflow, copy, and we're done.
170 if ( (size_t)(tp - tmp) > size ) {
177 #endif /* HAVE_IPV6 */
178 #endif /* HAVE_INET_NTOP */
181 } /* end extern "C" */