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/port/inet_net_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#ifndef FRONTEND
25#include "postgres.h"
26#else
27#include "postgres_fe.h"
28#endif
29
30#include <sys/socket.h>
31#include <netinet/in.h>
32#include <arpa/inet.h>
33
34#ifndef FRONTEND
35#include "utils/inet.h"
36#else
37/*
38 * In a frontend build, we can't include inet.h, but we still need to have
39 * sensible definitions of these two constants. Note that inet_net_ntop()
40 * assumes that PGSQL_AF_INET is equal to AF_INET.
41 */
42#define PGSQL_AF_INET (AF_INET + 0)
43#define PGSQL_AF_INET6 (AF_INET + 1)
44#endif
45
46
47#define NS_IN6ADDRSZ 16
48#define NS_INT16SZ 2
49
50#ifdef SPRINTF_CHAR
51#define SPRINTF(x) strlen(sprintf/**/x)
52#else
53#define SPRINTF(x) ((size_t)sprintf x)
54#endif
55
56static char *inet_net_ntop_ipv4(const u_char *src, int bits,
57 char *dst, size_t size);
58static char *inet_net_ntop_ipv6(const u_char *src, int bits,
59 char *dst, size_t size);
60
61
62/*
63 * char *
64 * inet_net_ntop(af, src, bits, dst, size)
65 * convert host/network address from network to presentation format.
66 * "src"'s size is determined from its "af".
67 * return:
68 * pointer to dst, or NULL if an error occurred (check errno).
69 * note:
70 * 192.5.5.1/28 has a nonzero host part, which means it isn't a network
71 * as called for by inet_net_pton() but it can be a host address with
72 * an included netmask.
73 * author:
74 * Paul Vixie (ISC), October 1998
75 */
76char *
77inet_net_ntop(int af, const void *src, int bits, char *dst, size_t size)
78{
79 /*
80 * We need to cover both the address family constants used by the PG inet
81 * type (PGSQL_AF_INET and PGSQL_AF_INET6) and those used by the system
82 * libraries (AF_INET and AF_INET6). We can safely assume PGSQL_AF_INET
83 * == AF_INET, but the INET6 constants are very likely to be different. If
84 * AF_INET6 isn't defined, silently ignore it.
85 */
86 switch (af)
87 {
88 case PGSQL_AF_INET:
89 return (inet_net_ntop_ipv4(src, bits, dst, size));
90 case PGSQL_AF_INET6:
91#if defined(AF_INET6) && AF_INET6 != PGSQL_AF_INET6
92 case AF_INET6:
93#endif
94 return (inet_net_ntop_ipv6(src, bits, dst, size));
95 default:
96 errno = EAFNOSUPPORT;
97 return (NULL);
98 }
99}
100
101/*
102 * static char *
103 * inet_net_ntop_ipv4(src, bits, dst, size)
104 * convert IPv4 network address from network to presentation format.
105 * "src"'s size is determined from its "af".
106 * return:
107 * pointer to dst, or NULL if an error occurred (check errno).
108 * note:
109 * network byte order assumed. this means 192.5.5.240/28 has
110 * 0b11110000 in its fourth octet.
111 * author:
112 * Paul Vixie (ISC), October 1998
113 */
114static char *
115inet_net_ntop_ipv4(const u_char *src, int bits, char *dst, size_t size)
116{
117 char *odst = dst;
118 char *t;
119 int len = 4;
120 int b;
121
122 if (bits < 0 || bits > 32)
123 {
124 errno = EINVAL;
125 return (NULL);
126 }
127
128 /* Always format all four octets, regardless of mask length. */
129 for (b = len; b > 0; b--)
130 {
131 if (size <= sizeof ".255")
132 goto emsgsize;
133 t = dst;
134 if (dst != odst)
135 *dst++ = '.';
136 dst += SPRINTF((dst, "%u", *src++));
137 size -= (size_t) (dst - t);
138 }
139
140 /* don't print masklen if 32 bits */
141 if (bits != 32)
142 {
143 if (size <= sizeof "/32")
144 goto emsgsize;
145 dst += SPRINTF((dst, "/%u", bits));
146 }
147
148 return (odst);
149
150emsgsize:
151 errno = EMSGSIZE;
152 return (NULL);
153}
154
155static int
156decoct(const u_char *src, int bytes, char *dst, size_t size)
157{
158 char *odst = dst;
159 char *t;
160 int b;
161
162 for (b = 1; b <= bytes; b++)
163 {
164 if (size <= sizeof "255.")
165 return (0);
166 t = dst;
167 dst += SPRINTF((dst, "%u", *src++));
168 if (b != bytes)
169 {
170 *dst++ = '.';
171 *dst = '\0';
172 }
173 size -= (size_t) (dst - t);
174 }
175 return (dst - odst);
176}
177
178static char *
179inet_net_ntop_ipv6(const u_char *src, int bits, char *dst, size_t size)
180{
181 /*
182 * Note that int32_t and int16_t need only be "at least" large enough to
183 * contain a value of the specified size. On some systems, like Crays,
184 * there is no such thing as an integer variable with 16 bits. Keep this
185 * in mind if you think this function should have been coded to use
186 * pointer overlays. All the world's not a VAX.
187 */
188 char tmp[sizeof "ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255/128"];
189 char *tp;
190 struct
191 {
192 int base,
193 len;
194 } best, cur;
195 u_int words[NS_IN6ADDRSZ / NS_INT16SZ];
196 int i;
197
198 if ((bits < -1) || (bits > 128))
199 {
200 errno = EINVAL;
201 return (NULL);
202 }
203
204 /*
205 * Preprocess: Copy the input (bytewise) array into a wordwise array. Find
206 * the longest run of 0x00's in src[] for :: shorthanding.
207 */
208 memset(words, '\0', sizeof words);
209 for (i = 0; i < NS_IN6ADDRSZ; i++)
210 words[i / 2] |= (src[i] << ((1 - (i % 2)) << 3));
211 best.base = -1;
212 cur.base = -1;
213 best.len = 0;
214 cur.len = 0;
215 for (i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); i++)
216 {
217 if (words[i] == 0)
218 {
219 if (cur.base == -1)
220 cur.base = i, cur.len = 1;
221 else
222 cur.len++;
223 }
224 else
225 {
226 if (cur.base != -1)
227 {
228 if (best.base == -1 || cur.len > best.len)
229 best = cur;
230 cur.base = -1;
231 }
232 }
233 }
234 if (cur.base != -1)
235 {
236 if (best.base == -1 || cur.len > best.len)
237 best = cur;
238 }
239 if (best.base != -1 && best.len < 2)
240 best.base = -1;
241
242 /*
243 * Format the result.
244 */
245 tp = tmp;
246 for (i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); i++)
247 {
248 /* Are we inside the best run of 0x00's? */
249 if (best.base != -1 && i >= best.base &&
250 i < (best.base + best.len))
251 {
252 if (i == best.base)
253 *tp++ = ':';
254 continue;
255 }
256 /* Are we following an initial run of 0x00s or any real hex? */
257 if (i != 0)
258 *tp++ = ':';
259 /* Is this address an encapsulated IPv4? */
260 if (i == 6 && best.base == 0 && (best.len == 6 ||
261 (best.len == 7 && words[7] != 0x0001) ||
262 (best.len == 5 && words[5] == 0xffff)))
263 {
264 int n;
265
266 n = decoct(src + 12, 4, tp, sizeof tmp - (tp - tmp));
267 if (n == 0)
268 {
269 errno = EMSGSIZE;
270 return (NULL);
271 }
272 tp += strlen(tp);
273 break;
274 }
275 tp += SPRINTF((tp, "%x", words[i]));
276 }
277
278 /* Was it a trailing run of 0x00's? */
279 if (best.base != -1 && (best.base + best.len) ==
280 (NS_IN6ADDRSZ / NS_INT16SZ))
281 *tp++ = ':';
282 *tp = '\0';
283
284 if (bits != -1 && bits != 128)
285 tp += SPRINTF((tp, "/%u", bits));
286
287 /*
288 * Check for overflow, copy, and we're done.
289 */
290 if ((size_t) (tp - tmp) > size)
291 {
292 errno = EMSGSIZE;
293 return (NULL);
294 }
295 strcpy(dst, tmp);
296 return (dst);
297}
298