2 * SPDX-License-Identifier: ISC
4 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
5 * Copyright (c) 1998,1999 by Internet Software Consortium.
7 * Permission to use, copy, modify, and distribute this software for any
8 * purpose with or without fee is hereby granted, provided that the above
9 * copyright notice and this permission notice appear in all copies.
11 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
12 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR
14 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
17 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
20 #if defined(LIBC_SCCS) && !defined(lint)
21 static const char rcsid[] = "$Id: inet_cidr_ntop.c,v 1.7 2006/10/11 02:18:18 marka Exp $";
23 #include <sys/cdefs.h>
24 __FBSDID("$FreeBSD$");
26 #include "port_before.h"
28 #include <sys/types.h>
29 #include <sys/socket.h>
30 #include <netinet/in.h>
31 #include <arpa/nameser.h>
32 #include <arpa/inet.h>
39 #include "port_after.h"
42 # define SPRINTF(x) strlen(sprintf/**/x)
44 # define SPRINTF(x) ((size_t)sprintf x)
48 inet_cidr_ntop_ipv4(const u_char *src, int bits, char *dst, size_t size);
50 inet_cidr_ntop_ipv6(const u_char *src, int bits, char *dst, size_t size);
54 * inet_cidr_ntop(af, src, bits, dst, size)
55 * convert network address from network to presentation format.
56 * "src"'s size is determined from its "af".
58 * pointer to dst, or NULL if an error occurred (check errno).
60 * 192.5.5.1/28 has a nonzero host part, which means it isn't a network
61 * as called for by inet_net_ntop() but it can be a host address with
62 * an included netmask.
64 * Paul Vixie (ISC), October 1998
67 inet_cidr_ntop(int af, const void *src, int bits, char *dst, size_t size) {
70 return (inet_cidr_ntop_ipv4(src, bits, dst, size));
72 return (inet_cidr_ntop_ipv6(src, bits, dst, size));
80 decoct(const u_char *src, int bytes, char *dst, size_t size) {
85 for (b = 1; b <= bytes; b++) {
86 if (size < sizeof "255.")
89 dst += SPRINTF((dst, "%u", *src++));
94 size -= (size_t)(dst - t);
101 * inet_cidr_ntop_ipv4(src, bits, dst, size)
102 * convert IPv4 network address from network to presentation format.
103 * "src"'s size is determined from its "af".
105 * pointer to dst, or NULL if an error occurred (check errno).
107 * network byte order assumed. this means 192.5.5.240/28 has
108 * 0b11110000 in its fourth octet.
110 * Paul Vixie (ISC), October 1998
113 inet_cidr_ntop_ipv4(const u_char *src, int bits, char *dst, size_t size) {
119 if ((bits < -1) || (bits > 32)) {
124 /* Find number of significant bytes in address. */
128 for (len = 1, b = 1 ; b < 4U; b++)
132 /* Format whole octets plus nonzero trailing octets. */
133 bytes = (((bits <= 0) ? 1 : bits) + 7) / 8;
136 b = decoct(src, bytes, dst, size);
143 /* Format CIDR /width. */
144 if (size < sizeof "/32")
146 dst += SPRINTF((dst, "/%u", bits));
157 inet_cidr_ntop_ipv6(const u_char *src, int bits, char *dst, size_t size) {
159 * Note that int32_t and int16_t need only be "at least" large enough
160 * to contain a value of the specified size. On some systems, like
161 * Crays, there is no such thing as an integer variable with 16 bits.
162 * Keep this in mind if you think this function should have been coded
163 * to use pointer overlays. All the world's not a VAX.
165 char tmp[sizeof "ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255/128"];
167 struct { int base, len; } best, cur;
168 u_int words[NS_IN6ADDRSZ / NS_INT16SZ];
171 if ((bits < -1) || (bits > 128)) {
178 * Copy the input (bytewise) array into a wordwise array.
179 * Find the longest run of 0x00's in src[] for :: shorthanding.
181 memset(words, '\0', sizeof words);
182 for (i = 0; i < NS_IN6ADDRSZ; i++)
183 words[i / 2] |= (src[i] << ((1 - (i % 2)) << 3));
188 for (i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); i++) {
191 cur.base = i, cur.len = 1;
195 if (cur.base != -1) {
196 if (best.base == -1 || cur.len > best.len)
202 if (cur.base != -1) {
203 if (best.base == -1 || cur.len > best.len)
206 if (best.base != -1 && best.len < 2)
213 for (i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); i++) {
214 /* Are we inside the best run of 0x00's? */
215 if (best.base != -1 && i >= best.base &&
216 i < (best.base + best.len)) {
221 /* Are we following an initial run of 0x00s or any real hex? */
224 /* Is this address an encapsulated IPv4? */
225 if (i == 6 && best.base == 0 && (best.len == 6 ||
226 (best.len == 7 && words[7] != 0x0001) ||
227 (best.len == 5 && words[5] == 0xffff))) {
230 if (src[15] || bits == -1 || bits > 120)
232 else if (src[14] || bits > 112)
236 n = decoct(src+12, n, tp, sizeof tmp - (tp - tmp));
244 tp += SPRINTF((tp, "%x", words[i]));
247 /* Was it a trailing run of 0x00's? */
248 if (best.base != -1 && (best.base + best.len) ==
249 (NS_IN6ADDRSZ / NS_INT16SZ))
254 tp += SPRINTF((tp, "/%u", bits));
257 * Check for overflow, copy, and we're done.
259 if ((size_t)(tp - tmp) > size) {