inet_ntop.cc
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1 /*
2  * Copyright (C) 1996-2017 The Squid Software Foundation and contributors
3  *
4  * Squid software is distributed under GPLv2+ license and includes
5  * contributions from numerous individuals and organizations.
6  * Please see the COPYING and CONTRIBUTORS files for details.
7  */
8 
9 /*
10  * Shamelessly duplicated from the bind9 public sources
11  * for use by the Squid Project under ISC written permission
12  * included "as found" below.
13  *
14  * Update/Maintenance History:
15  *
16  * 24-Sep-2007 : Copied from bind 9.3.3
17  * - Added protection around libray headers
18  * - Altered configure checks
19  * - Un-hacked slightly to use system gethostbyname()
20  *
21  * 06-Oct-2007 : Various fixes to allow the build on MinGW
22  *
23  * 28-Oct-2007: drop some dead code. now tested working without.
24  *
25  * 04-Nov-2010: drop SPRINTF casting macro
26  *
27  * 13-Jan-2015 : Various fixed for C++ and MinGW native build
28  *
29  * Original License and code follows.
30  */
31 
32 #include "squid.h"
33 
34 #if !HAVE_DECL_INET_NTOP
35 
36 /*
37  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
38  * Copyright (c) 1996-1999 by Internet Software Consortium.
39  *
40  * Permission to use, copy, modify, and distribute this software for any
41  * purpose with or without fee is hereby granted, provided that the above
42  * copyright notice and this permission notice appear in all copies.
43  *
44  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
45  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
46  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR
47  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
48  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
49  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
50  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
51  */
52 
53 #if defined(LIBC_SCCS) && !defined(lint)
54 static const char rcsid[] = "inet_ntop.c,v 1.1.2.1.8.2 2005/11/03 23:08:40 marka Exp";
55 #endif /* LIBC_SCCS and not lint */
56 
57 #if HAVE_SYS_PARAM_H
58 #include <sys/param.h>
59 #endif
60 #if HAVE_SYS_TYPES_H
61 #include <sys/types.h>
62 #endif
63 #if HAVE_SYS_SOCKET_H
64 #include <sys/socket.h>
65 #endif
66 
67 #if HAVE_NETINET_IN_H
68 #include <netinet/in.h>
69 #endif
70 #if HAVE_ARPA_INET_H
71 #include <arpa/inet.h>
72 #endif
73 #if HAVE_ARPA_NAMESER_H
74 #include <arpa/nameser.h>
75 #endif
76 
77 #if HAVE_ERRNO_H
78 #include <errno.h>
79 #endif
80 #if HAVE_STRING_H
81 #include <string.h>
82 #endif
83 
84 #if ! defined(NS_INADDRSZ)
85 #define NS_INADDRSZ 4
86 #endif
87 #if ! defined(NS_IN6ADDRSZ)
88 #define NS_IN6ADDRSZ 16
89 #endif
90 #if ! defined(NS_INT16SZ)
91 #define NS_INT16SZ 2
92 #endif
93 
94 /*
95  * WARNING: Don't even consider trying to compile this on a system where
96  * sizeof(int) < 4. sizeof(int) > 4 is fine; all the world's not a VAX.
97  */
98 
99 static const char *inet_ntop4 (const u_char *src, char *dst, size_t size);
100 static const char *inet_ntop6 (const u_char *src, char *dst, size_t size);
101 
102 /* char *
103  * inet_ntop(af, src, dst, size)
104  * convert a network format address to presentation format.
105  * return:
106  * pointer to presentation format address (`dst'), or NULL (see errno).
107  * author:
108  * Paul Vixie, 1996.
109  */
110 const char *
111 xinet_ntop(int af, const void *src, char *dst, size_t size)
112 {
113  switch (af) {
114  case AF_INET:
115  return (inet_ntop4((const u_char*)src, dst, size));
116  case AF_INET6:
117  return (inet_ntop6((const u_char*)src, dst, size));
118  default:
119  errno = EAFNOSUPPORT;
120  return (NULL);
121  }
122  /* NOTREACHED */
123 }
124 
125 /* const char *
126  * inet_ntop4(src, dst, size)
127  * format an IPv4 address
128  * return:
129  * `dst' (as a const)
130  * notes:
131  * (1) uses no statics
132  * (2) takes a u_char* not an in_addr as input
133  * author:
134  * Paul Vixie, 1996.
135  */
136 static const char *
137 inet_ntop4(const u_char *src, char *dst, size_t size)
138 {
139  static const char fmt[] = "%u.%u.%u.%u";
140  char tmp[sizeof("255.255.255.255")+1];
141 
142  if ((size_t)snprintf(tmp, min(sizeof(tmp),size), fmt, src[0], src[1], src[2], src[3]) >= size) {
143  errno = ENOSPC;
144  return (NULL);
145  }
146  strcpy(dst, tmp);
147  return (dst);
148 }
149 
150 /* const char *
151  * inet_ntop6(src, dst, size)
152  * convert IPv6 binary address into presentation (printable) format
153  * author:
154  * Paul Vixie, 1996.
155  */
156 static const char *
157 inet_ntop6(const u_char *src, char *dst, size_t size)
158 {
159  /*
160  * Note that int32_t and int16_t need only be "at least" large enough
161  * to contain a value of the specified size. On some systems, like
162  * Crays, there is no such thing as an integer variable with 16 bits.
163  * Keep this in mind if you think this function should have been coded
164  * to use pointer overlays. All the world's not a VAX.
165  */
166  char tmp[sizeof "ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255"], *tp;
167  struct { int base, len; } best, cur;
168  u_int words[NS_IN6ADDRSZ / NS_INT16SZ];
169  int i;
170 
171  /*
172  * Preprocess:
173  * Copy the input (bytewise) array into a wordwise array.
174  * Find the longest run of 0x00's in src[] for :: shorthanding.
175  */
176  memset(words, '\0', sizeof words);
177  for (i = 0; i < NS_IN6ADDRSZ; i++)
178  words[i / 2] |= (src[i] << ((1 - (i % 2)) << 3));
179  best.base = -1;
180  best.len = 0;
181  cur.base = -1;
182  cur.len = 0;
183  for (i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); i++) {
184  if (words[i] == 0) {
185  if (cur.base == -1)
186  cur.base = i, cur.len = 1;
187  else
188  cur.len++;
189  } else {
190  if (cur.base != -1) {
191  if (best.base == -1 || cur.len > best.len)
192  best = cur;
193  cur.base = -1;
194  }
195  }
196  }
197  if (cur.base != -1) {
198  if (best.base == -1 || cur.len > best.len)
199  best = cur;
200  }
201  if (best.base != -1 && best.len < 2)
202  best.base = -1;
203 
204  /*
205  * Format the result.
206  */
207  tp = tmp;
208  for (i = 0; i < (NS_IN6ADDRSZ / NS_INT16SZ); i++) {
209  /* Are we inside the best run of 0x00's? */
210  if (best.base != -1 && i >= best.base &&
211  i < (best.base + best.len)) {
212  if (i == best.base)
213  *tp++ = ':';
214  continue;
215  }
216  /* Are we following an initial run of 0x00s or any real hex? */
217  if (i != 0)
218  *tp++ = ':';
219  /* Is this address an encapsulated IPv4? */
220  if (i == 6 && best.base == 0 && (best.len == 6 ||
221  (best.len == 7 && words[7] != 0x0001) ||
222  (best.len == 5 && words[5] == 0xffff))) {
223  if (!inet_ntop4(src+12, tp, sizeof tmp - (tp - tmp)))
224  return (NULL);
225  tp += strlen(tp);
226  break;
227  }
228  tp += snprintf(tp, (tmp + sizeof("ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255") - tp), "%x", words[i]);
229  }
230  /* Was it a trailing run of 0x00's? */
231  if (best.base != -1 && (best.base + best.len) ==
232  (NS_IN6ADDRSZ / NS_INT16SZ))
233  *tp++ = ':';
234  *tp++ = '\0';
235 
236  /*
237  * Check for overflow, copy, and we're done.
238  */
239  if ((size_t)(tp - tmp) > size) {
240  errno = ENOSPC;
241  return (NULL);
242  }
243  strcpy(dst, tmp);
244  return (dst);
245 }
246 
247 #endif /* HAVE_DECL_INET_NTOP */
248 
int i
Definition: membanger.c:49
#define NS_IN6ADDRSZ
Definition: inet_ntop.cc:88
static const char * inet_ntop4(const u_char *src, char *dst, size_t size)
Definition: inet_ntop.cc:137
int cur
Definition: ModDevPoll.cc:76
int unsigned int const char *desc STUB void int len
Definition: stub_fd.cc:20
static const char * inet_ntop6(const u_char *src, char *dst, size_t size)
Definition: inet_ntop.cc:157
const char * xinet_ntop(int af, const void *src, char *dst, size_t size)
Definition: inet_ntop.cc:111
#define NS_INT16SZ
Definition: inet_ntop.cc:91
#define NULL
Definition: types.h:166
int size
Definition: ModDevPoll.cc:77
A const & min(A const &lhs, A const &rhs)

 

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