summaryrefslogtreecommitdiff
path: root/nss/digits_dots.c
blob: 0c1fa97e3977a81e2d13ab6783e9e11e1ed48422 (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
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
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
/* Copyright (C) 1997-2017 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by H.J. Lu <hjl@gnu.ai.mit.edu>, 1997.

   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
   <http://www.gnu.org/licenses/>.  */

#include <assert.h>
#include <errno.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>
#include <wctype.h>
#include <resolv/resolv-internal.h>
#include <resolv/resolv_context.h>
#include <netdb.h>
#include <arpa/inet.h>
#include "nsswitch.h"

#ifdef USE_NSCD
# define inet_aton __inet_aton
# include <nscd/nscd_proto.h>
#endif

int
__nss_hostname_digits_dots (const char *name, struct hostent *resbuf,
			    char **buffer, size_t *buffer_size,
			    size_t buflen, struct hostent **result,
			    enum nss_status *status, int af, int *h_errnop)
{
  /* We have to test for the use of IPv6 which can only be done by
     examining `_res'.  */
  struct resolv_context *ctx = __resolv_context_get ();
  if (ctx == NULL)
    {
      if (h_errnop)
	*h_errnop = NETDB_INTERNAL;
      if (buffer_size == NULL)
	*status = NSS_STATUS_TRYAGAIN;
      else
	*result = NULL;
      return -1;
    }
  int ret = __nss_hostname_digits_dots_context
    (ctx, name, resbuf, buffer, buffer_size, buflen,
     result, status, af, h_errnop);
  __resolv_context_put (ctx);
  return ret;
}

int
__nss_hostname_digits_dots_context (struct resolv_context *ctx,
				    const char *name, struct hostent *resbuf,
				    char **buffer, size_t *buffer_size,
				    size_t buflen, struct hostent **result,
				    enum nss_status *status, int af, int *h_errnop)
{
  int save;

  /*
   * disallow names consisting only of digits/dots, unless
   * they end in a dot.
   */
  if (isdigit (name[0]) || isxdigit (name[0]) || name[0] == ':')
    {
      const char *cp;
      char *hostname;
      typedef unsigned char host_addr_t[16];
      host_addr_t *host_addr;
      typedef char *host_addr_list_t[2];
      host_addr_list_t *h_addr_ptrs;
      char **h_alias_ptr;
      size_t size_needed;
      int addr_size;

      switch (af)
	{
	case AF_INET:
	  addr_size = INADDRSZ;
	  break;

	case AF_INET6:
	  addr_size = IN6ADDRSZ;
	  break;

	default:
	  af = res_use_inet6 () ? AF_INET6 : AF_INET;
	  addr_size = af == AF_INET6 ? IN6ADDRSZ : INADDRSZ;
	  break;
	}

      size_needed = (sizeof (*host_addr)
		     + sizeof (*h_addr_ptrs)
		     + sizeof (*h_alias_ptr) + strlen (name) + 1);

      if (buffer_size == NULL)
        {
	  if (buflen < size_needed)
	    {
	      *status = NSS_STATUS_TRYAGAIN;
	      if (h_errnop != NULL)
		*h_errnop = NETDB_INTERNAL;
	      __set_errno (ERANGE);
	      goto done;
	    }
	}
      else if (buffer_size != NULL && *buffer_size < size_needed)
	{
	  char *new_buf;
	  *buffer_size = size_needed;
	  new_buf = (char *) realloc (*buffer, *buffer_size);

	  if (new_buf == NULL)
	    {
	      save = errno;
	      free (*buffer);
	      *buffer = NULL;
	      *buffer_size = 0;
	      __set_errno (save);
	      if (h_errnop != NULL)
		*h_errnop = NETDB_INTERNAL;
	      *result = NULL;
	      goto done;
	    }
	  *buffer = new_buf;
	}

      memset (*buffer, '\0', size_needed);

      host_addr = (host_addr_t *) *buffer;
      h_addr_ptrs = (host_addr_list_t *)
	((char *) host_addr + sizeof (*host_addr));
      h_alias_ptr = (char **) ((char *) h_addr_ptrs + sizeof (*h_addr_ptrs));
      hostname = (char *) h_alias_ptr + sizeof (*h_alias_ptr);

      if (isdigit (name[0]))
	{
	  for (cp = name;; ++cp)
	    {
	      if (*cp == '\0')
		{
		  int ok;

		  if (*--cp == '.')
		    break;

		  /* All-numeric, no dot at the end. Fake up a hostent as if
		     we'd actually done a lookup.  What if someone types
		     255.255.255.255?  The test below will succeed
		     spuriously... ???  */
		  if (af == AF_INET)
		    ok = __inet_aton (name, (struct in_addr *) host_addr);
		  else
		    {
		      assert (af == AF_INET6);
		      ok = inet_pton (af, name, host_addr) > 0;
		    }
		  if (! ok)
		    {
		      *h_errnop = HOST_NOT_FOUND;
		      if (buffer_size == NULL)
			*status = NSS_STATUS_NOTFOUND;
		      else
			*result = NULL;
		      goto done;
		    }

		  resbuf->h_name = strcpy (hostname, name);
		  h_alias_ptr[0] = NULL;
		  resbuf->h_aliases = h_alias_ptr;
		  (*h_addr_ptrs)[0] = (char *) host_addr;
		  (*h_addr_ptrs)[1] = NULL;
		  resbuf->h_addr_list = *h_addr_ptrs;
		  if (af == AF_INET && res_use_inet6 ())
		    {
		      /* We need to change the IP v4 address into the
			 IP v6 address.  */
		      char tmp[INADDRSZ];
		      char *p = (char *) host_addr;
		      int i;

		      /* Save a copy of the IP v4 address. */
		      memcpy (tmp, host_addr, INADDRSZ);
		      /* Mark this ipv6 addr as a mapped ipv4. */
		      for (i = 0; i < 10; i++)
			*p++ = 0x00;
		      *p++ = 0xff;
		      *p++ = 0xff;
		      /* Copy the IP v4 address. */
		      memcpy (p, tmp, INADDRSZ);
		      resbuf->h_addrtype = AF_INET6;
		      resbuf->h_length = IN6ADDRSZ;
		    }
		  else
		    {
		      resbuf->h_addrtype = af;
		      resbuf->h_length = addr_size;
		    }
		  if (h_errnop != NULL)
		    *h_errnop = NETDB_SUCCESS;
		  if (buffer_size == NULL)
		    *status = NSS_STATUS_SUCCESS;
		  else
		    *result = resbuf;
		  goto done;
		}

	      if (!isdigit (*cp) && *cp != '.')
		break;
	    }
	}

      if ((isxdigit (name[0]) && strchr (name, ':') != NULL) || name[0] == ':')
	{
	  switch (af)
	    {
	    default:
	      af = res_use_inet6 () ? AF_INET6 : AF_INET;
	      if (af == AF_INET6)
		{
		  addr_size = IN6ADDRSZ;
		  break;
		}
	      /* FALLTHROUGH */

	    case AF_INET:
	      /* This is not possible.  We cannot represent an IPv6 address
		 in an `struct in_addr' variable.  */
	      *h_errnop = HOST_NOT_FOUND;
	      if (buffer_size == NULL)
		*status = NSS_STATUS_NOTFOUND;
	      else
		*result = NULL;
	      goto done;

	    case AF_INET6:
	      addr_size = IN6ADDRSZ;
	      break;
	    }

	  for (cp = name;; ++cp)
	    {
	      if (!*cp)
		{
		  if (*--cp == '.')
		    break;

		  /* All-IPv6-legal, no dot at the end. Fake up a
		     hostent as if we'd actually done a lookup.  */
		  if (inet_pton (AF_INET6, name, host_addr) <= 0)
		    {
		      *h_errnop = HOST_NOT_FOUND;
		      if (buffer_size == NULL)
			*status = NSS_STATUS_NOTFOUND;
		      else
			*result = NULL;
		      goto done;
		    }

		  resbuf->h_name = strcpy (hostname, name);
		  h_alias_ptr[0] = NULL;
		  resbuf->h_aliases = h_alias_ptr;
		  (*h_addr_ptrs)[0] = (char *) host_addr;
		  (*h_addr_ptrs)[1] = (char *) 0;
		  resbuf->h_addr_list = *h_addr_ptrs;
		  resbuf->h_addrtype = AF_INET6;
		  resbuf->h_length = addr_size;
		  *h_errnop = NETDB_SUCCESS;
		  if (buffer_size == NULL)
		    *status = NSS_STATUS_SUCCESS;
		  else
		    *result = resbuf;
		  goto done;
		}

	      if (!isxdigit (*cp) && *cp != ':' && *cp != '.')
		break;
	    }
	}
    }

  return 0;

done:
  return 1;
}
libc_hidden_def (__nss_hostname_digits_dots)