2 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
3 * Copyright (c) 1996,1999 by 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
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
15 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18 #if defined(LIBC_SCCS) && !defined(lint)
19 static const char rcsid[] = "$Id: inet_net_ntop.c,v 1.3.18.2 2006/06/20 02:51:32 marka Exp $";
22 #include "port_before.h"
24 #include <sys/types.h>
25 #include <sys/socket.h>
26 #include <netinet/in.h>
27 #include <arpa/inet.h>
34 #include "port_after.h"
37 # define SPRINTF(x) strlen(sprintf/**/x)
39 # define SPRINTF(x) ((size_t)sprintf x)
42 static char * inet_net_ntop_ipv4 __P((const u_char *src, int bits,
43 char *dst, size_t size));
44 static char * inet_net_ntop_ipv6 __P((const u_char *src, int bits,
45 char *dst, size_t size));
49 * inet_net_ntop(af, src, bits, dst, size)
50 * convert network number from network to presentation format.
51 * generates CIDR style result always.
53 * pointer to dst, or NULL if an error occurred (check errno).
55 * Paul Vixie (ISC), July 1996
58 inet_net_ntop(af, src, bits, dst, size)
67 return (inet_net_ntop_ipv4(src, bits, dst, size));
69 return (inet_net_ntop_ipv6(src, bits, dst, size));
78 * inet_net_ntop_ipv4(src, bits, dst, size)
79 * convert IPv4 network number from network to presentation format.
80 * generates CIDR style result always.
82 * pointer to dst, or NULL if an error occurred (check errno).
84 * network byte order assumed. this means 192.5.5.240/28 has
85 * 0b11110000 in its fourth octet.
87 * Paul Vixie (ISC), July 1996
90 inet_net_ntop_ipv4(src, bits, dst, size)
101 if (bits < 0 || bits > 32) {
107 if (size < sizeof "0")
114 /* Format whole octets. */
115 for (b = bits / 8; b > 0; b--) {
116 if (size <= sizeof "255.")
119 dst += SPRINTF((dst, "%u", *src++));
124 size -= (size_t)(dst - t);
127 /* Format partial octet. */
130 if (size <= sizeof ".255")
135 m = ((1 << b) - 1) << (8 - b);
136 dst += SPRINTF((dst, "%u", *src & m));
137 size -= (size_t)(dst - t);
140 /* Format CIDR /width. */
141 if (size <= sizeof "/32")
143 dst += SPRINTF((dst, "/%u", bits));
153 * inet_net_ntop_ipv6(src, bits, fakebits, dst, size)
154 * convert IPv6 network number from network to presentation format.
155 * generates CIDR style result always. Picks the shortest representation
156 * unless the IP is really IPv4.
157 * always prints specified number of bits (bits).
159 * pointer to dst, or NULL if an error occurred (check errno).
161 * network byte order assumed. this means 192.5.5.240/28 has
162 * 0x11110000 in its fourth octet.
164 * Vadim Kogan (UCB), June 2001
165 * Original version (IPv4) by Paul Vixie (ISC), July 1996
169 inet_net_ntop_ipv6(const u_char *src, int bits, char *dst, size_t size) {
173 int zero_s, zero_l, tmp_zero_s, tmp_zero_l;
176 unsigned char inbuf[16];
177 char outbuf[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255/128")];
182 if (bits < 0 || bits > 128) {
194 /* Copy src to private buffer. Zero host part. */
196 memcpy(inbuf, src, p);
197 memset(inbuf + p, 0, 16 - p);
206 /* how many words need to be displayed in output */
207 words = (bits + 15) / 16;
211 /* Find the longest substring of zero's */
212 zero_s = zero_l = tmp_zero_s = tmp_zero_l = 0;
213 for (i = 0; i < (words * 2); i += 2) {
214 if ((s[i] | s[i+1]) == 0) {
219 if (tmp_zero_l && zero_l < tmp_zero_l) {
227 if (tmp_zero_l && zero_l < tmp_zero_l) {
232 if (zero_l != words && zero_s == 0 && ((zero_l == 6) ||
233 ((zero_l == 5 && s[10] == 0xff && s[11] == 0xff) ||
234 ((zero_l == 7 && s[14] != 0 && s[15] != 1)))))
237 /* Format whole words. */
238 for (p = 0; p < words; p++) {
239 if (zero_l != 0 && p >= zero_s && p < zero_s + zero_l) {
240 /* Time to skip some zeros */
250 if (is_ipv4 && p > 5 ) {
251 *cp++ = (p == 6) ? ':' : '.';
252 cp += SPRINTF((cp, "%u", *s++));
253 /* we can potentially drop the last octet */
254 if (p != 7 || bits > 120) {
256 cp += SPRINTF((cp, "%u", *s++));
261 cp += SPRINTF((cp, "%x", *s * 256 + s[1]));
266 /* Format CIDR /width. */
267 sprintf(cp, "/%u", bits);
268 if (strlen(outbuf) + 1 > size)