summaryrefslogtreecommitdiffstats
path: root/Utilities/cmcurl/lib/inet_ntop.c
blob: fb91a505db994f53b1b46ae4e35a3b703c0173e3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
/*
 * Copyright (C) 1996-2001  Internet Software Consortium.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM
 * DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
 * INTERNET SOFTWARE CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT,
 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
 * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
 * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
 * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */
/*
 * Original code by Paul Vixie. "curlified" by Gisle Vanem.
 */

#include "curl_setup.h"

#ifndef HAVE_INET_NTOP

#ifdef HAVE_SYS_PARAM_H
#include <sys/param.h>
#endif
#ifdef HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif
#ifdef HAVE_ARPA_INET_H
#include <arpa/inet.h>
#endif

#include "inet_ntop.h"
#include "curl_printf.h"

#define IN6ADDRSZ       16
#define INADDRSZ         4
#define INT16SZ          2

/*
 * Format an IPv4 address, more or less like inet_ntoa().
 *
 * Returns `dst' (as a const)
 * Note:
 *  - uses no statics
 *  - takes a unsigned char* not an in_addr as input
 */
static char *inet_ntop4 (const unsigned char *src, char *dst, size_t size)
{
  char tmp[sizeof "255.255.255.255"];
  size_t len;

  DEBUGASSERT(size >= 16);

  tmp[0] = '\0';
  (void)snprintf(tmp, sizeof(tmp), "%d.%d.%d.%d",
                 ((int)((unsigned char)src[0])) & 0xff,
                 ((int)((unsigned char)src[1])) & 0xff,
                 ((int)((unsigned char)src[2])) & 0xff,
                 ((int)((unsigned char)src[3])) & 0xff);

  len = strlen(tmp);
  if(len == 0 || len >= size) {
    errno = ENOSPC;
    return (NULL);
  }
  strcpy(dst, tmp);
  return dst;
}

#ifdef ENABLE_IPV6
/*
 * Convert IPv6 binary address into presentation (printable) format.
 */
static char *inet_ntop6 (const unsigned char *src, char *dst, size_t size)
{
  /*
   * Note that int32_t and int16_t need only be "at least" large enough
   * to contain a value of the specified size.  On some systems, like
   * Crays, there is no such thing as an integer variable with 16 bits.
   * Keep this in mind if you think this function should have been coded
   * to use pointer overlays.  All the world's not a VAX.
   */
  char tmp[sizeof("ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255")];
  char *tp;
  struct {
    long base;
    long len;
  } best, cur;
  unsigned long words[IN6ADDRSZ / INT16SZ];
  int i;

  /* Preprocess:
   *  Copy the input (bytewise) array into a wordwise array.
   *  Find the longest run of 0x00's in src[] for :: shorthanding.
   */
  memset(words, '\0', sizeof(words));
  for(i = 0; i < IN6ADDRSZ; i++)
    words[i/2] |= (src[i] << ((1 - (i % 2)) << 3));

  best.base = -1;
  cur.base  = -1;
  best.len = 0;
  cur.len = 0;

  for(i = 0; i < (IN6ADDRSZ / INT16SZ); i++) {
    if(words[i] == 0) {
      if(cur.base == -1)
        cur.base = i, cur.len = 1;
      else
        cur.len++;
    }
    else if(cur.base != -1) {
      if(best.base == -1 || cur.len > best.len)
        best = cur;
      cur.base = -1;
    }
  }
  if((cur.base != -1) && (best.base == -1 || cur.len > best.len))
    best = cur;
  if(best.base != -1 && best.len < 2)
    best.base = -1;
  /* Format the result. */
  tp = tmp;
  for(i = 0; i < (IN6ADDRSZ / INT16SZ); i++) {
    /* Are we inside the best run of 0x00's? */
    if(best.base != -1 && i >= best.base && i < (best.base + best.len)) {
      if(i == best.base)
        *tp++ = ':';
      continue;
    }

    /* Are we following an initial run of 0x00s or any real hex?
     */
    if(i != 0)
      *tp++ = ':';

    /* Is this address an encapsulated IPv4?
     */
    if(i == 6 && best.base == 0 &&
        (best.len == 6 || (best.len == 5 && words[5] == 0xffff))) {
      if(!inet_ntop4(src + 12, tp, sizeof(tmp) - (tp - tmp))) {
        errno = ENOSPC;
        return (NULL);
      }
      tp += strlen(tp);
      break;
    }
    tp += snprintf(tp, 5, "%lx", words[i]);
  }

  /* Was it a trailing run of 0x00's?
   */
  if(best.base != -1 && (best.base + best.len) == (IN6ADDRSZ / INT16SZ))
     *tp++ = ':';
  *tp++ = '\0';

  /* Check for overflow, copy, and we're done.
   */
  if((size_t)(tp - tmp) > size) {
    errno = ENOSPC;
    return (NULL);
  }
  strcpy(dst, tmp);
  return dst;
}
#endif  /* ENABLE_IPV6 */

/*
 * Convert a network format address to presentation format.
 *
 * Returns pointer to presentation format address (`buf').
 * Returns NULL on error and errno set with the specific
 * error, EAFNOSUPPORT or ENOSPC.
 *
 * On Windows we store the error in the thread errno, not
 * in the winsock error code. This is to avoid losing the
 * actual last winsock error. So when this function returns
 * NULL, check errno not SOCKERRNO.
 */
char *Curl_inet_ntop(int af, const void *src, char *buf, size_t size)
{
  switch(af) {
  case AF_INET:
    return inet_ntop4((const unsigned char *)src, buf, size);
#ifdef ENABLE_IPV6
  case AF_INET6:
    return inet_ntop6((const unsigned char *)src, buf, size);
#endif
  default:
    errno = EAFNOSUPPORT;
    return NULL;
  }
}
#endif  /* HAVE_INET_NTOP */