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_net_ntop.c
18 */
19
20 #if defined(LIBC_SCCS) && !defined(lint)
21 static 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/types.h>
31 #include <sys/socket.h>
32 #include <netinet/in.h>
33 #include <arpa/inet.h>
34
35 #ifndef FRONTEND
36 #include "utils/inet.h"
37 #else
38 /*
39 * In a frontend build, we can't include inet.h, but we still need to have
40 * sensible definitions of these two constants. Note that inet_net_ntop()
41 * assumes that PGSQL_AF_INET is equal to AF_INET.
42 */
43 #define PGSQL_AF_INET (AF_INET + 0)
44 #define PGSQL_AF_INET6 (AF_INET + 1)
45 #endif
46
47
48 #define NS_IN6ADDRSZ 16
49 #define NS_INT16SZ 2
50
51 #ifdef SPRINTF_CHAR
52 #define SPRINTF(x) strlen(sprintf/**/x)
53 #else
54 #define SPRINTF(x) ((size_t)sprintf x)
55 #endif
56
57 static char *inet_net_ntop_ipv4(const u_char *src, int bits,
58 char *dst, size_t size);
59 static char *inet_net_ntop_ipv6(const u_char *src, int bits,
60 char *dst, size_t size);
61
62
63 /*
64 * char *
65 * inet_net_ntop(af, src, bits, dst, size)
66 * convert host/network address from network to presentation format.
67 * "src"'s size is determined from its "af".
68 * return:
69 * pointer to dst, or NULL if an error occurred (check errno).
70 * note:
71 * 192.5.5.1/28 has a nonzero host part, which means it isn't a network
72 * as called for by inet_net_pton() but it can be a host address with
73 * an included netmask.
74 * author:
75 * Paul Vixie (ISC), October 1998
76 */
77 char *
inet_net_ntop(int af,const void * src,int bits,char * dst,size_t size)78 inet_net_ntop(int af, const void *src, int bits, char *dst, size_t size)
79 {
80 /*
81 * We need to cover both the address family constants used by the PG inet
82 * type (PGSQL_AF_INET and PGSQL_AF_INET6) and those used by the system
83 * libraries (AF_INET and AF_INET6). We can safely assume PGSQL_AF_INET
84 * == AF_INET, but the INET6 constants are very likely to be different. If
85 * AF_INET6 isn't defined, silently ignore it.
86 */
87 switch (af)
88 {
89 case PGSQL_AF_INET:
90 return (inet_net_ntop_ipv4(src, bits, dst, size));
91 case PGSQL_AF_INET6:
92 #if defined(AF_INET6) && AF_INET6 != PGSQL_AF_INET6
93 case AF_INET6:
94 #endif
95 return (inet_net_ntop_ipv6(src, bits, dst, size));
96 default:
97 errno = EAFNOSUPPORT;
98 return (NULL);
99 }
100 }
101
102 /*
103 * static char *
104 * inet_net_ntop_ipv4(src, bits, dst, size)
105 * convert IPv4 network address from network to presentation format.
106 * "src"'s size is determined from its "af".
107 * return:
108 * pointer to dst, or NULL if an error occurred (check errno).
109 * note:
110 * network byte order assumed. this means 192.5.5.240/28 has
111 * 0b11110000 in its fourth octet.
112 * author:
113 * Paul Vixie (ISC), October 1998
114 */
115 static char *
inet_net_ntop_ipv4(const u_char * src,int bits,char * dst,size_t size)116 inet_net_ntop_ipv4(const u_char *src, int bits, char *dst, size_t size)
117 {
118 char *odst = dst;
119 char *t;
120 int len = 4;
121 int b;
122
123 if (bits < 0 || bits > 32)
124 {
125 errno = EINVAL;
126 return (NULL);
127 }
128
129 /* Always format all four octets, regardless of mask length. */
130 for (b = len; b > 0; b--)
131 {
132 if (size <= sizeof ".255")
133 goto emsgsize;
134 t = dst;
135 if (dst != odst)
136 *dst++ = '.';
137 dst += SPRINTF((dst, "%u", *src++));
138 size -= (size_t) (dst - t);
139 }
140
141 /* don't print masklen if 32 bits */
142 if (bits != 32)
143 {
144 if (size <= sizeof "/32")
145 goto emsgsize;
146 dst += SPRINTF((dst, "/%u", bits));
147 }
148
149 return (odst);
150
151 emsgsize:
152 errno = EMSGSIZE;
153 return (NULL);
154 }
155
156 static int
decoct(const u_char * src,int bytes,char * dst,size_t size)157 decoct(const u_char *src, int bytes, char *dst, size_t size)
158 {
159 char *odst = dst;
160 char *t;
161 int b;
162
163 for (b = 1; b <= bytes; b++)
164 {
165 if (size <= sizeof "255.")
166 return (0);
167 t = dst;
168 dst += SPRINTF((dst, "%u", *src++));
169 if (b != bytes)
170 {
171 *dst++ = '.';
172 *dst = '\0';
173 }
174 size -= (size_t) (dst - t);
175 }
176 return (dst - odst);
177 }
178
179 static char *
inet_net_ntop_ipv6(const u_char * src,int bits,char * dst,size_t size)180 inet_net_ntop_ipv6(const u_char *src, int bits, char *dst, size_t size)
181 {
182 /*
183 * Note that int32_t and int16_t need only be "at least" large enough to
184 * contain a value of the specified size. On some systems, like Crays,
185 * there is no such thing as an integer variable with 16 bits. Keep this
186 * in mind if you think this function should have been coded to use
187 * pointer overlays. All the world's not a VAX.
188 */
189 char tmp[sizeof "ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255/128"];
190 char *tp;
191 struct
192 {
193 int base,
194 len;
195 } best, cur;
196 u_int words[NS_IN6ADDRSZ / NS_INT16SZ];
197 int i;
198
199 if ((bits < -1) || (bits > 128))
200 {
201 errno = EINVAL;
202 return (NULL);
203 }
204
205 /*
206 * Preprocess: Copy the input (bytewise) array into a wordwise array. Find
207 * the longest run of 0x00's in src[] for :: shorthanding.
208 */
209 memset(words, '\0', sizeof words);
210 for (i = 0; i < NS_IN6ADDRSZ; i++)
211 words[i / 2] |= (src[i] << ((1 - (i % 2)) << 3));
212 best.base = -1;
213 cur.base = -1;
214 best.len = 0;
215 cur.len = 0;
216 for (i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); i++)
217 {
218 if (words[i] == 0)
219 {
220 if (cur.base == -1)
221 cur.base = i, cur.len = 1;
222 else
223 cur.len++;
224 }
225 else
226 {
227 if (cur.base != -1)
228 {
229 if (best.base == -1 || cur.len > best.len)
230 best = cur;
231 cur.base = -1;
232 }
233 }
234 }
235 if (cur.base != -1)
236 {
237 if (best.base == -1 || cur.len > best.len)
238 best = cur;
239 }
240 if (best.base != -1 && best.len < 2)
241 best.base = -1;
242
243 /*
244 * Format the result.
245 */
246 tp = tmp;
247 for (i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); i++)
248 {
249 /* Are we inside the best run of 0x00's? */
250 if (best.base != -1 && i >= best.base &&
251 i < (best.base + best.len))
252 {
253 if (i == best.base)
254 *tp++ = ':';
255 continue;
256 }
257 /* Are we following an initial run of 0x00s or any real hex? */
258 if (i != 0)
259 *tp++ = ':';
260 /* Is this address an encapsulated IPv4? */
261 if (i == 6 && best.base == 0 && (best.len == 6 ||
262 (best.len == 7 && words[7] != 0x0001) ||
263 (best.len == 5 && words[5] == 0xffff)))
264 {
265 int n;
266
267 n = decoct(src + 12, 4, tp, sizeof tmp - (tp - tmp));
268 if (n == 0)
269 {
270 errno = EMSGSIZE;
271 return (NULL);
272 }
273 tp += strlen(tp);
274 break;
275 }
276 tp += SPRINTF((tp, "%x", words[i]));
277 }
278
279 /* Was it a trailing run of 0x00's? */
280 if (best.base != -1 && (best.base + best.len) ==
281 (NS_IN6ADDRSZ / NS_INT16SZ))
282 *tp++ = ':';
283 *tp = '\0';
284
285 if (bits != -1 && bits != 128)
286 tp += SPRINTF((tp, "/%u", bits));
287
288 /*
289 * Check for overflow, copy, and we're done.
290 */
291 if ((size_t) (tp - tmp) > size)
292 {
293 errno = EMSGSIZE;
294 return (NULL);
295 }
296 strcpy(dst, tmp);
297 return (dst);
298 }
299