summary refs log tree commit diff
path: root/resolv/inet_pton.c
blob: 163d5a64324aece8778bcb7de2ee23475ae9d6e3 (plain) (blame)
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
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
/* Copyright (C) 1996-2020 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <https://www.gnu.org/licenses/>.  */

/*
 * Copyright (c) 1996,1999 by 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.
 */

#include <arpa/inet.h>
#include <arpa/nameser.h>
#include <ctype.h>
#include <errno.h>
#include <netinet/in.h>
#include <resolv/resolv-internal.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/types.h>

static int inet_pton4 (const char *src, const char *src_end, u_char *dst);
static int inet_pton6 (const char *src, const char *src_end, u_char *dst);

int
__inet_pton_length (int af, const char *src, size_t srclen, void *dst)
{
  switch (af)
    {
    case AF_INET:
      return inet_pton4 (src, src + srclen, dst);
    case AF_INET6:
      return inet_pton6 (src, src + srclen, dst);
    default:
      __set_errno (EAFNOSUPPORT);
      return -1;
    }
}
libc_hidden_def (__inet_pton_length)

/* Like __inet_pton_length, but use strlen (SRC) as the length of
   SRC.  */
int
__inet_pton (int af, const char *src, void *dst)
{
  return __inet_pton_length (af, src, strlen (src), dst);
}
libc_hidden_def (__inet_pton)
weak_alias (__inet_pton, inet_pton)
libc_hidden_weak (inet_pton)

/* Like inet_aton but without all the hexadecimal, octal and shorthand
   (and trailing garbage is not ignored).  Return 1 if SRC is a valid
   dotted quad, else 0.  This function does not touch DST unless it's
   returning 1.
   Author: Paul Vixie, 1996.  */
static int
inet_pton4 (const char *src, const char *end, unsigned char *dst)
{
  int saw_digit, octets, ch;
  unsigned char tmp[NS_INADDRSZ], *tp;

  saw_digit = 0;
  octets = 0;
  *(tp = tmp) = 0;
  while (src < end)
    {
      ch = *src++;
      if (ch >= '0' && ch <= '9')
        {
          unsigned int new = *tp * 10 + (ch - '0');

          if (saw_digit && *tp == 0)
            return 0;
          if (new > 255)
            return 0;
          *tp = new;
          if (! saw_digit)
            {
              if (++octets > 4)
                return 0;
              saw_digit = 1;
            }
        }
      else if (ch == '.' && saw_digit)
        {
          if (octets == 4)
            return 0;
          *++tp = 0;
          saw_digit = 0;
        }
      else
        return 0;
    }
  if (octets < 4)
    return 0;
  memcpy (dst, tmp, NS_INADDRSZ);
  return 1;
}

/* Return the value of CH as a hexademical digit, or -1 if it is a
   different type of character.  */
static int
hex_digit_value (char ch)
{
  if ('0' <= ch && ch <= '9')
    return ch - '0';
  if ('a' <= ch && ch <= 'f')
    return ch - 'a' + 10;
  if ('A' <= ch && ch <= 'F')
    return ch - 'A' + 10;
  return -1;
}

/* Convert presentation-level IPv6 address to network order binary
   form.  Return 1 if SRC is a valid [RFC1884 2.2] address, else 0.
   This function does not touch DST unless it's returning 1.
   Author: Paul Vixie, 1996.  Inspired by Mark Andrews.  */
static int
inet_pton6 (const char *src, const char *src_endp, unsigned char *dst)
{
  unsigned char tmp[NS_IN6ADDRSZ], *tp, *endp, *colonp;
  const char *curtok;
  int ch;
  size_t xdigits_seen;	/* Number of hex digits since colon.  */
  unsigned int val;

  tp = memset (tmp, '\0', NS_IN6ADDRSZ);
  endp = tp + NS_IN6ADDRSZ;
  colonp = NULL;

  /* Leading :: requires some special handling.  */
  if (src == src_endp)
    return 0;
  if (*src == ':')
    {
      ++src;
      if (src == src_endp || *src != ':')
        return 0;
    }

  curtok = src;
  xdigits_seen = 0;
  val = 0;
  while (src < src_endp)
    {
      ch = *src++;
      int digit = hex_digit_value (ch);
      if (digit >= 0)
	{
	  if (xdigits_seen == 4)
	    return 0;
	  val <<= 4;
	  val |= digit;
	  if (val > 0xffff)
	    return 0;
	  ++xdigits_seen;
	  continue;
	}
      if (ch == ':')
	{
	  curtok = src;
	  if (xdigits_seen == 0)
	    {
	      if (colonp)
		return 0;
	      colonp = tp;
	      continue;
	    }
	  else if (src == src_endp)
            return 0;
	  if (tp + NS_INT16SZ > endp)
	    return 0;
	  *tp++ = (unsigned char) (val >> 8) & 0xff;
	  *tp++ = (unsigned char) val & 0xff;
	  xdigits_seen = 0;
	  val = 0;
	  continue;
	}
      if (ch == '.' && ((tp + NS_INADDRSZ) <= endp)
          && inet_pton4 (curtok, src_endp, tp) > 0)
	{
	  tp += NS_INADDRSZ;
	  xdigits_seen = 0;
	  break;  /* '\0' was seen by inet_pton4.  */
	}
      return 0;
    }
  if (xdigits_seen > 0)
    {
      if (tp + NS_INT16SZ > endp)
	return 0;
      *tp++ = (unsigned char) (val >> 8) & 0xff;
      *tp++ = (unsigned char) val & 0xff;
    }
  if (colonp != NULL)
    {
      /* Replace :: with zeros.  */
      if (tp == endp)
        /* :: would expand to a zero-width field.  */
        return 0;
      size_t n = tp - colonp;
      memmove (endp - n, colonp, n);
      memset (colonp, 0, endp - n - colonp);
      tp = endp;
    }
  if (tp != endp)
    return 0;
  memcpy (dst, tmp, NS_IN6ADDRSZ);
  return 1;
}