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inet_cidr_ntop.c
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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 #include "postgres.h"
25 
26 #include <sys/types.h>
27 #include <sys/socket.h>
28 #include <netinet/in.h>
29 #include <arpa/inet.h>
30 
31 #include "utils/builtins.h"
32 #include "utils/inet.h"
33 
34 
35 #ifdef SPRINTF_CHAR
36 #define SPRINTF(x) strlen(sprintfx)
37 #else
38 #define SPRINTF(x) ((size_t)sprintf x)
39 #endif
40 
41 static char *inet_cidr_ntop_ipv4(const u_char *src, int bits,
42  char *dst, size_t size);
43 static char *inet_cidr_ntop_ipv6(const u_char *src, int bits,
44  char *dst, size_t size);
45 
46 /*
47  * char *
48  * inet_cidr_ntop(af, src, bits, dst, size)
49  * convert network number from network to presentation format.
50  * generates CIDR style result always.
51  * return:
52  * pointer to dst, or NULL if an error occurred (check errno).
53  * author:
54  * Paul Vixie (ISC), July 1996
55  */
56 char *
57 inet_cidr_ntop(int af, const void *src, int bits, char *dst, size_t size)
58 {
59  switch (af)
60  {
61  case PGSQL_AF_INET:
62  return (inet_cidr_ntop_ipv4(src, bits, dst, size));
63  case PGSQL_AF_INET6:
64  return (inet_cidr_ntop_ipv6(src, bits, dst, size));
65  default:
66  errno = EAFNOSUPPORT;
67  return (NULL);
68  }
69 }
70 
71 
72 /*
73  * static char *
74  * inet_cidr_ntop_ipv4(src, bits, dst, size)
75  * convert IPv4 network number from network to presentation format.
76  * generates CIDR style result always.
77  * return:
78  * pointer to dst, or NULL if an error occurred (check errno).
79  * note:
80  * network byte order assumed. this means 192.5.5.240/28 has
81  * 0b11110000 in its fourth octet.
82  * author:
83  * Paul Vixie (ISC), July 1996
84  */
85 static char *
86 inet_cidr_ntop_ipv4(const u_char *src, int bits, char *dst, size_t size)
87 {
88  char *odst = dst;
89  char *t;
90  u_int m;
91  int b;
92 
93  if (bits < 0 || bits > 32)
94  {
95  errno = EINVAL;
96  return (NULL);
97  }
98 
99  if (bits == 0)
100  {
101  if (size < sizeof "0")
102  goto emsgsize;
103  *dst++ = '0';
104  size--;
105  *dst = '\0';
106  }
107 
108  /* Format whole octets. */
109  for (b = bits / 8; b > 0; b--)
110  {
111  if (size <= sizeof "255.")
112  goto emsgsize;
113  t = dst;
114  dst += SPRINTF((dst, "%u", *src++));
115  if (b > 1)
116  {
117  *dst++ = '.';
118  *dst = '\0';
119  }
120  size -= (size_t) (dst - t);
121  }
122 
123  /* Format partial octet. */
124  b = bits % 8;
125  if (b > 0)
126  {
127  if (size <= sizeof ".255")
128  goto emsgsize;
129  t = dst;
130  if (dst != odst)
131  *dst++ = '.';
132  m = ((1 << b) - 1) << (8 - b);
133  dst += SPRINTF((dst, "%u", *src & m));
134  size -= (size_t) (dst - t);
135  }
136 
137  /* Format CIDR /width. */
138  if (size <= sizeof "/32")
139  goto emsgsize;
140  dst += SPRINTF((dst, "/%u", bits));
141  return (odst);
142 
143 emsgsize:
144  errno = EMSGSIZE;
145  return (NULL);
146 }
147 
148 /*
149  * static char *
150  * inet_cidr_ntop_ipv6(src, bits, fakebits, dst, size)
151  * convert IPv6 network number from network to presentation format.
152  * generates CIDR style result always. Picks the shortest representation
153  * unless the IP is really IPv4.
154  * always prints specified number of bits (bits).
155  * return:
156  * pointer to dst, or NULL if an error occurred (check errno).
157  * note:
158  * network byte order assumed. this means 192.5.5.240/28 has
159  * 0x11110000 in its fourth octet.
160  * author:
161  * Vadim Kogan (UCB), June 2001
162  * Original version (IPv4) by Paul Vixie (ISC), July 1996
163  */
164 
165 static char *
166 inet_cidr_ntop_ipv6(const u_char *src, int bits, char *dst, size_t size)
167 {
168  u_int m;
169  int b;
170  int p;
171  int zero_s,
172  zero_l,
173  tmp_zero_s,
174  tmp_zero_l;
175  int i;
176  int is_ipv4 = 0;
177  unsigned char inbuf[16];
178  char outbuf[sizeof("xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255/128")];
179  char *cp;
180  int words;
181  u_char *s;
182 
183  if (bits < 0 || bits > 128)
184  {
185  errno = EINVAL;
186  return (NULL);
187  }
188 
189  cp = outbuf;
190 
191  if (bits == 0)
192  {
193  *cp++ = ':';
194  *cp++ = ':';
195  *cp = '\0';
196  }
197  else
198  {
199  /* Copy src to private buffer. Zero host part. */
200  p = (bits + 7) / 8;
201  memcpy(inbuf, src, p);
202  memset(inbuf + p, 0, 16 - p);
203  b = bits % 8;
204  if (b != 0)
205  {
206  m = ~0 << (8 - b);
207  inbuf[p - 1] &= m;
208  }
209 
210  s = inbuf;
211 
212  /* how many words need to be displayed in output */
213  words = (bits + 15) / 16;
214  if (words == 1)
215  words = 2;
216 
217  /* Find the longest substring of zero's */
218  zero_s = zero_l = tmp_zero_s = tmp_zero_l = 0;
219  for (i = 0; i < (words * 2); i += 2)
220  {
221  if ((s[i] | s[i + 1]) == 0)
222  {
223  if (tmp_zero_l == 0)
224  tmp_zero_s = i / 2;
225  tmp_zero_l++;
226  }
227  else
228  {
229  if (tmp_zero_l && zero_l < tmp_zero_l)
230  {
231  zero_s = tmp_zero_s;
232  zero_l = tmp_zero_l;
233  tmp_zero_l = 0;
234  }
235  }
236  }
237 
238  if (tmp_zero_l && zero_l < tmp_zero_l)
239  {
240  zero_s = tmp_zero_s;
241  zero_l = tmp_zero_l;
242  }
243 
244  if (zero_l != words && zero_s == 0 && ((zero_l == 6) ||
245  ((zero_l == 5 && s[10] == 0xff && s[11] == 0xff) ||
246  ((zero_l == 7 && s[14] != 0 && s[15] != 1)))))
247  is_ipv4 = 1;
248 
249  /* Format whole words. */
250  for (p = 0; p < words; p++)
251  {
252  if (zero_l != 0 && p >= zero_s && p < zero_s + zero_l)
253  {
254  /* Time to skip some zeros */
255  if (p == zero_s)
256  *cp++ = ':';
257  if (p == words - 1)
258  *cp++ = ':';
259  s++;
260  s++;
261  continue;
262  }
263 
264  if (is_ipv4 && p > 5)
265  {
266  *cp++ = (p == 6) ? ':' : '.';
267  cp += SPRINTF((cp, "%u", *s++));
268  /* we can potentially drop the last octet */
269  if (p != 7 || bits > 120)
270  {
271  *cp++ = '.';
272  cp += SPRINTF((cp, "%u", *s++));
273  }
274  }
275  else
276  {
277  if (cp != outbuf)
278  *cp++ = ':';
279  cp += SPRINTF((cp, "%x", *s * 256 + s[1]));
280  s += 2;
281  }
282  }
283  }
284  /* Format CIDR /width. */
285  (void) SPRINTF((cp, "/%u", bits));
286  if (strlen(outbuf) + 1 > size)
287  goto emsgsize;
288  strcpy(dst, outbuf);
289 
290  return (dst);
291 
292 emsgsize:
293  errno = EMSGSIZE;
294  return (NULL);
295 }
#define PGSQL_AF_INET
Definition: inet.h:39
static char * inet_cidr_ntop_ipv4(const u_char *src, int bits, char *dst, size_t size)
#define PGSQL_AF_INET6
Definition: inet.h:40
#define SPRINTF(x)
#define EMSGSIZE
Definition: win32.h:297
char * inet_cidr_ntop(int af, const void *src, int bits, char *dst, size_t size)
static char * inet_cidr_ntop_ipv6(const u_char *src, int bits, char *dst, size_t size)
#define EAFNOSUPPORT
Definition: win32.h:299
#define NULL
Definition: c.h:226
int i