1 /*-
2 * SPDX-License-Identifier: ISC
3 *
4 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
5 * Copyright (c) 1996,1999 by Internet Software Consortium.
6 *
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.
10 *
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.
18 */
19
20 #include "port_before.h"
21
22 #include <sys/types.h>
23 #include <sys/socket.h>
24 #include <netinet/in.h>
25 #include <arpa/inet.h>
26
27 #include <errno.h>
28 #include <stdio.h>
29 #include <string.h>
30 #include <stdlib.h>
31
32 #include "port_after.h"
33
34 #ifdef SPRINTF_CHAR
35 # define SPRINTF(x) strlen(sprintf/**/x)
36 #else
37 # define SPRINTF(x) ((size_t)sprintf x)
38 #endif
39
40 static char * inet_net_ntop_ipv4(const u_char *src, int bits, char *dst,
41 size_t size);
42 static char * inet_net_ntop_ipv6(const u_char *src, int bits, char *dst,
43 size_t size);
44
45 /*%
46 * char *
47 * inet_net_ntop(af, src, bits, dst, size)
48 * convert network number from network to presentation format.
49 * generates CIDR style result always.
50 * return:
51 * pointer to dst, or NULL if an error occurred (check errno).
52 * author:
53 * Paul Vixie (ISC), July 1996
54 */
55 char *
inet_net_ntop(int af,const void * src,int bits,char * dst,size_t size)56 inet_net_ntop(int af, const void *src, int bits, char *dst, size_t size)
57 {
58 switch (af) {
59 case AF_INET:
60 return (inet_net_ntop_ipv4(src, bits, dst, size));
61 case AF_INET6:
62 return (inet_net_ntop_ipv6(src, bits, dst, size));
63 default:
64 errno = EAFNOSUPPORT;
65 return (NULL);
66 }
67 }
68
69 /*%
70 * static char *
71 * inet_net_ntop_ipv4(src, bits, dst, size)
72 * convert IPv4 network number from network to presentation format.
73 * generates CIDR style result always.
74 * return:
75 * pointer to dst, or NULL if an error occurred (check errno).
76 * note:
77 * network byte order assumed. this means 192.5.5.240/28 has
78 * 0b11110000 in its fourth octet.
79 * author:
80 * Paul Vixie (ISC), July 1996
81 */
82 static char *
inet_net_ntop_ipv4(const u_char * src,int bits,char * dst,size_t size)83 inet_net_ntop_ipv4(const u_char *src, int bits, char *dst, size_t size)
84 {
85 char *odst = dst;
86 char *t;
87 u_int m;
88 int b;
89
90 if (bits < 0 || bits > 32) {
91 errno = EINVAL;
92 return (NULL);
93 }
94
95 if (bits == 0) {
96 if (size < sizeof "0")
97 goto emsgsize;
98 *dst++ = '0';
99 size--;
100 *dst = '\0';
101 }
102
103 /* Format whole octets. */
104 for (b = bits / 8; b > 0; b--) {
105 if (size <= sizeof "255.")
106 goto emsgsize;
107 t = dst;
108 dst += SPRINTF((dst, "%u", *src++));
109 if (b > 1) {
110 *dst++ = '.';
111 *dst = '\0';
112 }
113 size -= (size_t)(dst - t);
114 }
115
116 /* Format partial octet. */
117 b = bits % 8;
118 if (b > 0) {
119 if (size <= sizeof ".255")
120 goto emsgsize;
121 t = dst;
122 if (dst != odst)
123 *dst++ = '.';
124 m = ((1 << b) - 1) << (8 - b);
125 dst += SPRINTF((dst, "%u", *src & m));
126 size -= (size_t)(dst - t);
127 }
128
129 /* Format CIDR /width. */
130 if (size <= sizeof "/32")
131 goto emsgsize;
132 dst += SPRINTF((dst, "/%u", bits));
133 return (odst);
134
135 emsgsize:
136 errno = EMSGSIZE;
137 return (NULL);
138 }
139
140 /*%
141 * static char *
142 * inet_net_ntop_ipv6(src, bits, fakebits, dst, size)
143 * convert IPv6 network number from network to presentation format.
144 * generates CIDR style result always. Picks the shortest representation
145 * unless the IP is really IPv4.
146 * always prints specified number of bits (bits).
147 * return:
148 * pointer to dst, or NULL if an error occurred (check errno).
149 * note:
150 * network byte order assumed. this means 192.5.5.240/28 has
151 * 0b11110000 in its fourth octet.
152 * author:
153 * Vadim Kogan (UCB), June 2001
154 * Original version (IPv4) by Paul Vixie (ISC), July 1996
155 */
156
157 static char *
inet_net_ntop_ipv6(const u_char * src,int bits,char * dst,size_t size)158 inet_net_ntop_ipv6(const u_char *src, int bits, char *dst, size_t size) {
159 u_int m;
160 int b;
161 int p;
162 int zero_s, zero_l, tmp_zero_s, tmp_zero_l;
163 int i;
164 int is_ipv4 = 0;
165 unsigned char inbuf[16];
166 char outbuf[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255/128")];
167 char *cp;
168 int words;
169 u_char *s;
170
171 if (bits < 0 || bits > 128) {
172 errno = EINVAL;
173 return (NULL);
174 }
175
176 cp = outbuf;
177
178 if (bits == 0) {
179 *cp++ = ':';
180 *cp++ = ':';
181 *cp = '\0';
182 } else {
183 /* Copy src to private buffer. Zero host part. */
184 p = (bits + 7) / 8;
185 memcpy(inbuf, src, p);
186 memset(inbuf + p, 0, 16 - p);
187 b = bits % 8;
188 if (b != 0) {
189 m = ~0 << (8 - b);
190 inbuf[p-1] &= m;
191 }
192
193 s = inbuf;
194
195 /* how many words need to be displayed in output */
196 words = (bits + 15) / 16;
197 if (words == 1)
198 words = 2;
199
200 /* Find the longest substring of zero's */
201 zero_s = zero_l = tmp_zero_s = tmp_zero_l = 0;
202 for (i = 0; i < (words * 2); i += 2) {
203 if ((s[i] | s[i+1]) == 0) {
204 if (tmp_zero_l == 0)
205 tmp_zero_s = i / 2;
206 tmp_zero_l++;
207 } else {
208 if (tmp_zero_l && zero_l < tmp_zero_l) {
209 zero_s = tmp_zero_s;
210 zero_l = tmp_zero_l;
211 tmp_zero_l = 0;
212 }
213 }
214 }
215
216 if (tmp_zero_l && zero_l < tmp_zero_l) {
217 zero_s = tmp_zero_s;
218 zero_l = tmp_zero_l;
219 }
220
221 if (zero_l != words && zero_s == 0 && ((zero_l == 6) ||
222 ((zero_l == 5 && s[10] == 0xff && s[11] == 0xff) ||
223 ((zero_l == 7 && s[14] != 0 && s[15] != 1)))))
224 is_ipv4 = 1;
225
226 /* Format whole words. */
227 for (p = 0; p < words; p++) {
228 if (zero_l != 0 && p >= zero_s && p < zero_s + zero_l) {
229 /* Time to skip some zeros */
230 if (p == zero_s)
231 *cp++ = ':';
232 if (p == words - 1)
233 *cp++ = ':';
234 s++;
235 s++;
236 continue;
237 }
238
239 if (is_ipv4 && p > 5 ) {
240 *cp++ = (p == 6) ? ':' : '.';
241 cp += SPRINTF((cp, "%u", *s++));
242 /* we can potentially drop the last octet */
243 if (p != 7 || bits > 120) {
244 *cp++ = '.';
245 cp += SPRINTF((cp, "%u", *s++));
246 }
247 } else {
248 if (cp != outbuf)
249 *cp++ = ':';
250 cp += SPRINTF((cp, "%x", *s * 256 + s[1]));
251 s += 2;
252 }
253 }
254 }
255 /* Format CIDR /width. */
256 sprintf(cp, "/%u", bits);
257 if (strlen(outbuf) + 1 > size)
258 goto emsgsize;
259 strcpy(dst, outbuf);
260
261 return (dst);
262
263 emsgsize:
264 errno = EMSGSIZE;
265 return (NULL);
266 }
267
268 /*
269 * Weak aliases for applications that use certain private entry points,
270 * and fail to include <arpa/inet.h>.
271 */
272 #undef inet_net_ntop
273 __weak_reference(__inet_net_ntop, inet_net_ntop);
274
275 /*! \file */
276