1 /*
2 * Copyright (c) 1996,1999 by Internet Software Consortium.
3 *
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.
7 *
8 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
9 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
10 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
11 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
12 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
13 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
14 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
15 * SOFTWARE.
16 */
17
18 #include <sys/cdefs.h>
19 #if defined(LIBC_SCCS) && !defined(lint)
20 #ifdef notdef
21 static const char rcsid[] = "Id: inet_net_ntop.c,v 1.1.2.1 2002/08/02 02:17:21 marka Exp ";
22 #else
23 __RCSID("$NetBSD: inet_net_ntop.c,v 1.3 2012/03/20 17:08:13 matt Exp $");
24 #endif
25 #endif
26
27 #include "port_before.h"
28
29 #include "namespace.h"
30 #include <sys/types.h>
31 #include <sys/socket.h>
32 #include <netinet/in.h>
33 #include <arpa/inet.h>
34
35 #include <errno.h>
36 #include <stdio.h>
37 #include <string.h>
38 #include <stdlib.h>
39
40 #include "port_after.h"
41
42 #ifdef __weak_alias
43 __weak_alias(inet_net_ntop,_inet_net_ntop)
44 #endif
45
46 #ifdef SPRINTF_CHAR
47 # define SPRINTF(x) strlen(sprintf/**/x)
48 #else
49 # define SPRINTF(x) sprintf x
50 #endif
51
52 static char * inet_net_ntop_ipv4(const u_char *src, int bits,
53 char *dst, size_t size);
54 static char * inet_net_ntop_ipv6(const u_char *src, int bits,
55 char *dst, size_t size);
56
57 /*
58 * char *
59 * inet_net_ntop(af, src, bits, dst, size)
60 * convert network number from network to presentation format.
61 * generates CIDR style result always.
62 * return:
63 * pointer to dst, or NULL if an error occurred (check errno).
64 * author:
65 * Paul Vixie (ISC), July 1996
66 */
67 char *
inet_net_ntop(int af,const void * src,int bits,char * dst,size_t size)68 inet_net_ntop(int af, const void *src, int bits, char *dst, size_t size)
69 {
70 switch (af) {
71 case AF_INET:
72 return (inet_net_ntop_ipv4(src, bits, dst, size));
73 case AF_INET6:
74 return (inet_net_ntop_ipv6(src, bits, dst, size));
75 default:
76 errno = EAFNOSUPPORT;
77 return (NULL);
78 }
79 }
80
81 /*
82 * static char *
83 * inet_net_ntop_ipv4(src, bits, dst, size)
84 * convert IPv4 network number from network to presentation format.
85 * generates CIDR style result always.
86 * return:
87 * pointer to dst, or NULL if an error occurred (check errno).
88 * note:
89 * network byte order assumed. this means 192.5.5.240/28 has
90 * 0b11110000 in its fourth octet.
91 * author:
92 * Paul Vixie (ISC), July 1996
93 */
94 static char *
inet_net_ntop_ipv4(const u_char * src,int bits,char * dst,size_t size)95 inet_net_ntop_ipv4(const u_char *src, int bits, char *dst, size_t size)
96 {
97 char *odst = dst;
98 char *t;
99 u_int m;
100 int b;
101
102 if (bits < 0 || bits > 32) {
103 errno = EINVAL;
104 return (NULL);
105 }
106
107 if (bits == 0) {
108 if (size < sizeof "0")
109 goto emsgsize;
110 *dst++ = '0';
111 size--;
112 *dst = '\0';
113 }
114
115 /* Format whole octets. */
116 for (b = bits / 8; b > 0; b--) {
117 if (size <= sizeof "255.")
118 goto emsgsize;
119 t = dst;
120 dst += SPRINTF((dst, "%u", *src++));
121 if (b > 1) {
122 *dst++ = '.';
123 *dst = '\0';
124 }
125 size -= (size_t)(dst - t);
126 }
127
128 /* Format partial octet. */
129 b = bits % 8;
130 if (b > 0) {
131 if (size <= sizeof ".255")
132 goto emsgsize;
133 t = dst;
134 if (dst != odst)
135 *dst++ = '.';
136 m = ((1 << b) - 1) << (8 - b);
137 dst += SPRINTF((dst, "%u", *src & m));
138 size -= (size_t)(dst - t);
139 }
140
141 /* Format CIDR /width. */
142 if (size <= sizeof "/32")
143 goto emsgsize;
144 dst += SPRINTF((dst, "/%u", bits));
145 return (odst);
146
147 emsgsize:
148 errno = EMSGSIZE;
149 return (NULL);
150 }
151
152 /*
153 * static char *
154 * inet_net_ntop_ipv6(src, bits, fakebits, dst, size)
155 * convert IPv6 network number from network to presentation format.
156 * generates CIDR style result always. Picks the shortest representation
157 * unless the IP is really IPv4.
158 * always prints specified number of bits (bits).
159 * return:
160 * pointer to dst, or NULL if an error occurred (check errno).
161 * note:
162 * network byte order assumed. this means 192.5.5.240/28 has
163 * 0x11110000 in its fourth octet.
164 * author:
165 * Vadim Kogan (UCB), June 2001
166 * Original version (IPv4) by Paul Vixie (ISC), July 1996
167 */
168
169 static char *
inet_net_ntop_ipv6(const u_char * src,int bits,char * dst,size_t size)170 inet_net_ntop_ipv6(const u_char *src, int bits, char *dst, size_t size)
171 {
172 u_int m;
173 int b;
174 size_t p;
175 size_t zero_s, zero_l, tmp_zero_s, tmp_zero_l;
176 size_t i;
177 int is_ipv4 = 0;
178 unsigned char inbuf[16];
179 char outbuf[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255/128")];
180 char *cp;
181 size_t words;
182 u_char *s;
183
184 if (bits < 0 || bits > 128) {
185 errno = EINVAL;
186 return (NULL);
187 }
188
189 cp = outbuf;
190
191 if (bits == 0) {
192 *cp++ = ':';
193 *cp++ = ':';
194 *cp = '\0';
195 } else {
196 /* Copy src to private buffer. Zero host part. */
197 p = (bits + 7) / 8;
198 memcpy(inbuf, src, p);
199 memset(inbuf + p, 0, 16 - p);
200 b = bits % 8;
201 if (b != 0) {
202 m = ~0 << (8 - b);
203 inbuf[p-1] &= m;
204 }
205
206 s = inbuf;
207
208 /* how many words need to be displayed in output */
209 words = (bits + 15) / 16;
210 if (words == 1)
211 words = 2;
212
213 /* Find the longest substring of zero's */
214 zero_s = zero_l = tmp_zero_s = tmp_zero_l = 0;
215 for (i = 0; i < (words * 2); i += 2) {
216 if ((s[i] | s[i+1]) == 0) {
217 if (tmp_zero_l == 0)
218 tmp_zero_s = i / 2;
219 tmp_zero_l++;
220 } else {
221 if (tmp_zero_l && zero_l < tmp_zero_l) {
222 zero_s = tmp_zero_s;
223 zero_l = tmp_zero_l;
224 tmp_zero_l = 0;
225 }
226 }
227 }
228
229 if (tmp_zero_l && zero_l < tmp_zero_l) {
230 zero_s = tmp_zero_s;
231 zero_l = tmp_zero_l;
232 }
233
234 if (zero_l != words && zero_s == 0 && ((zero_l == 6) ||
235 ((zero_l == 5 && s[10] == 0xff && s[11] == 0xff) ||
236 ((zero_l == 7 && s[14] != 0 && s[15] != 1)))))
237 is_ipv4 = 1;
238
239 /* Format whole words. */
240 for (p = 0; p < words; p++) {
241 if (zero_l != 0 && p >= zero_s && p < zero_s + zero_l) {
242 /* Time to skip some zeros */
243 if (p == zero_s)
244 *cp++ = ':';
245 if (p == words - 1)
246 *cp++ = ':';
247 s++;
248 s++;
249 continue;
250 }
251
252 if (is_ipv4 && p > 5 ) {
253 *cp++ = (p == 6) ? ':' : '.';
254 cp += SPRINTF((cp, "%u", *s++));
255 /* we can potentially drop the last octet */
256 if (p != 7 || bits > 120) {
257 *cp++ = '.';
258 cp += SPRINTF((cp, "%u", *s++));
259 }
260 } else {
261 if (cp != outbuf)
262 *cp++ = ':';
263 cp += SPRINTF((cp, "%x", *s * 256 + s[1]));
264 s += 2;
265 }
266 }
267 }
268 /* Format CIDR /width. */
269 (void)SPRINTF((cp, "/%u", bits));
270 if (strlen(outbuf) + 1 > size)
271 goto emsgsize;
272 strcpy(dst, outbuf);
273
274 return (dst);
275
276 emsgsize:
277 errno = EMSGSIZE;
278 return (NULL);
279 }
280