1/*
2 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
3 * Copyright (c) 1996,1999 by Internet Software Consortium.
4 *
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.
8 *
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.
16 *
17 * src/backend/utils/adt/inet_cidr_ntop.c
18 */
19
20#if defined(LIBC_SCCS) && !defined(lint)
21static const char rcsid[] = "Id: inet_net_ntop.c,v 1.1.2.2 2004/03/09 09:17:27 marka Exp $";
22#endif
23
24#include "postgres.h"
25
26#include <sys/socket.h>
27#include <netinet/in.h>
28#include <arpa/inet.h>
29
30#include "utils/builtins.h"
31#include "utils/inet.h"
32
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
40static char *inet_cidr_ntop_ipv4(const u_char *src, int bits,
41 char *dst, size_t size);
42static char *inet_cidr_ntop_ipv6(const u_char *src, int bits,
43 char *dst, size_t size);
44
45/*
46 * char *
47 * inet_cidr_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 */
55char *
56inet_cidr_ntop(int af, const void *src, int bits, char *dst, size_t size)
57{
58 switch (af)
59 {
60 case PGSQL_AF_INET:
61 return inet_cidr_ntop_ipv4(src, bits, dst, size);
62 case PGSQL_AF_INET6:
63 return inet_cidr_ntop_ipv6(src, bits, dst, size);
64 default:
65 errno = EAFNOSUPPORT;
66 return NULL;
67 }
68}
69
70
71/*
72 * static char *
73 * inet_cidr_ntop_ipv4(src, bits, dst, size)
74 * convert IPv4 network number from network to presentation format.
75 * generates CIDR style result always.
76 * return:
77 * pointer to dst, or NULL if an error occurred (check errno).
78 * note:
79 * network byte order assumed. this means 192.5.5.240/28 has
80 * 0b11110000 in its fourth octet.
81 * author:
82 * Paul Vixie (ISC), July 1996
83 */
84static char *
85inet_cidr_ntop_ipv4(const u_char *src, int bits, char *dst, size_t size)
86{
87 char *odst = dst;
88 char *t;
89 u_int m;
90 int b;
91
92 if (bits < 0 || bits > 32)
93 {
94 errno = EINVAL;
95 return NULL;
96 }
97
98 if (bits == 0)
99 {
100 if (size < sizeof "0")
101 goto emsgsize;
102 *dst++ = '0';
103 size--;
104 *dst = '\0';
105 }
106
107 /* Format whole octets. */
108 for (b = bits / 8; b > 0; b--)
109 {
110 if (size <= sizeof "255.")
111 goto emsgsize;
112 t = dst;
113 dst += SPRINTF((dst, "%u", *src++));
114 if (b > 1)
115 {
116 *dst++ = '.';
117 *dst = '\0';
118 }
119 size -= (size_t) (dst - t);
120 }
121
122 /* Format partial octet. */
123 b = bits % 8;
124 if (b > 0)
125 {
126 if (size <= sizeof ".255")
127 goto emsgsize;
128 t = dst;
129 if (dst != odst)
130 *dst++ = '.';
131 m = ((1 << b) - 1) << (8 - b);
132 dst += SPRINTF((dst, "%u", *src & m));
133 size -= (size_t) (dst - t);
134 }
135
136 /* Format CIDR /width. */
137 if (size <= sizeof "/32")
138 goto emsgsize;
139 dst += SPRINTF((dst, "/%u", bits));
140 return odst;
141
142emsgsize:
143 errno = EMSGSIZE;
144 return NULL;
145}
146
147/*
148 * static char *
149 * inet_cidr_ntop_ipv6(src, bits, fakebits, dst, size)
150 * convert IPv6 network number from network to presentation format.
151 * generates CIDR style result always. Picks the shortest representation
152 * unless the IP is really IPv4.
153 * always prints specified number of bits (bits).
154 * return:
155 * pointer to dst, or NULL if an error occurred (check errno).
156 * note:
157 * network byte order assumed. this means 192.5.5.240/28 has
158 * 0x11110000 in its fourth octet.
159 * author:
160 * Vadim Kogan (UCB), June 2001
161 * Original version (IPv4) by Paul Vixie (ISC), July 1996
162 */
163
164static char *
165inet_cidr_ntop_ipv6(const u_char *src, int bits, char *dst, size_t size)
166{
167 u_int m;
168 int b;
169 int p;
170 int zero_s,
171 zero_l,
172 tmp_zero_s,
173 tmp_zero_l;
174 int i;
175 int is_ipv4 = 0;
176 unsigned char inbuf[16];
177 char outbuf[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255/128")];
178 char *cp;
179 int words;
180 u_char *s;
181
182 if (bits < 0 || bits > 128)
183 {
184 errno = EINVAL;
185 return NULL;
186 }
187
188 cp = outbuf;
189
190 if (bits == 0)
191 {
192 *cp++ = ':';
193 *cp++ = ':';
194 *cp = '\0';
195 }
196 else
197 {
198 /* Copy src to private buffer. Zero host part. */
199 p = (bits + 7) / 8;
200 memcpy(inbuf, src, p);
201 memset(inbuf + p, 0, 16 - p);
202 b = bits % 8;
203 if (b != 0)
204 {
205 m = ((u_int) ~0) << (8 - b);
206 inbuf[p - 1] &= m;
207 }
208
209 s = inbuf;
210
211 /* how many words need to be displayed in output */
212 words = (bits + 15) / 16;
213 if (words == 1)
214 words = 2;
215
216 /* Find the longest substring of zero's */
217 zero_s = zero_l = tmp_zero_s = tmp_zero_l = 0;
218 for (i = 0; i < (words * 2); i += 2)
219 {
220 if ((s[i] | s[i + 1]) == 0)
221 {
222 if (tmp_zero_l == 0)
223 tmp_zero_s = i / 2;
224 tmp_zero_l++;
225 }
226 else
227 {
228 if (tmp_zero_l && zero_l < tmp_zero_l)
229 {
230 zero_s = tmp_zero_s;
231 zero_l = tmp_zero_l;
232 tmp_zero_l = 0;
233 }
234 }
235 }
236
237 if (tmp_zero_l && zero_l < tmp_zero_l)
238 {
239 zero_s = tmp_zero_s;
240 zero_l = tmp_zero_l;
241 }
242
243 if (zero_l != words && zero_s == 0 && ((zero_l == 6) ||
244 ((zero_l == 5 && s[10] == 0xff && s[11] == 0xff) ||
245 ((zero_l == 7 && s[14] != 0 && s[15] != 1)))))
246 is_ipv4 = 1;
247
248 /* Format whole words. */
249 for (p = 0; p < words; p++)
250 {
251 if (zero_l != 0 && p >= zero_s && p < zero_s + zero_l)
252 {
253 /* Time to skip some zeros */
254 if (p == zero_s)
255 *cp++ = ':';
256 if (p == words - 1)
257 *cp++ = ':';
258 s++;
259 s++;
260 continue;
261 }
262
263 if (is_ipv4 && p > 5)
264 {
265 *cp++ = (p == 6) ? ':' : '.';
266 cp += SPRINTF((cp, "%u", *s++));
267 /* we can potentially drop the last octet */
268 if (p != 7 || bits > 120)
269 {
270 *cp++ = '.';
271 cp += SPRINTF((cp, "%u", *s++));
272 }
273 }
274 else
275 {
276 if (cp != outbuf)
277 *cp++ = ':';
278 cp += SPRINTF((cp, "%x", *s * 256 + s[1]));
279 s += 2;
280 }
281 }
282 }
283 /* Format CIDR /width. */
284 (void) SPRINTF((cp, "/%u", bits));
285 if (strlen(outbuf) + 1 > size)
286 goto emsgsize;
287 strcpy(dst, outbuf);
288
289 return dst;
290
291emsgsize:
292 errno = EMSGSIZE;
293 return NULL;
294}
295