about summary refs log tree commit diff
path: root/nis/nss_nis/nis-hosts.c
blob: d6192b1c771daad098be7f90cc338f6fc2551fbc (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
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
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
/* Copyright (C) 1996-2014 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Thorsten Kukuk <kukuk@suse.de>, 1996.

   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 <nss.h>
#include <ctype.h>
/* The following is an ugly trick to avoid a prototype declaration for
   _nss_nis_endgrent.  */
#define _nss_nis_endhostent _nss_nis_endhostent_XXX
#include <netdb.h>
#undef _nss_nis_endhostent
#include <string.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <resolv.h>
#include <bits/libc-lock.h>
#include <rpcsvc/yp.h>
#include <rpcsvc/ypclnt.h>

#include "nss-nis.h"

/* Get implementation for some internal functions. */
#include <resolv/mapv4v6addr.h>

#define ENTNAME         hostent
#define DATABASE        "hosts"
#define NEED_H_ERRNO

#define EXTRA_ARGS      , af, flags
#define EXTRA_ARGS_DECL , int af, int flags

#define ENTDATA hostent_data
struct hostent_data
  {
    unsigned char host_addr[16];	/* IPv4 or IPv6 address.  */
    char *h_addr_ptrs[2];	/* Points to that and null terminator.  */
  };

#define TRAILING_LIST_MEMBER            h_aliases
#define TRAILING_LIST_SEPARATOR_P       isspace
#include <nss/nss_files/files-parse.c>
LINE_PARSER
("#",
 {
   char *addr;

   STRING_FIELD (addr, isspace, 1);

   assert (af == AF_INET || af == AF_INET6 || af == AF_UNSPEC);

   /* Parse address.  */
   if (af != AF_INET6 && inet_pton (AF_INET, addr, entdata->host_addr) > 0)
     {
       assert ((flags & AI_V4MAPPED) == 0 || af != AF_UNSPEC);
       if (flags & AI_V4MAPPED)
	 {
	   map_v4v6_address ((char *) entdata->host_addr,
			     (char *) entdata->host_addr);
	   result->h_addrtype = AF_INET6;
	   result->h_length = IN6ADDRSZ;
	 }
       else
	 {
	   result->h_addrtype = AF_INET;
	   result->h_length = INADDRSZ;
	 }
     }
   else if (af != AF_INET
	    && inet_pton (AF_INET6, addr, entdata->host_addr) > 0)
     {
       result->h_addrtype = AF_INET6;
       result->h_length = IN6ADDRSZ;
     }
   else
     /* Illegal address: ignore line.  */
     return 0;

   /* Store a pointer to the address in the expected form.  */
   entdata->h_addr_ptrs[0] = (char *) entdata->host_addr;
   entdata->h_addr_ptrs[1] = NULL;
   result->h_addr_list = entdata->h_addr_ptrs;

   STRING_FIELD (result->h_name, isspace, 1);
 })


__libc_lock_define_initialized (static, lock)

static bool_t new_start = 1;
static char *oldkey = NULL;
static int oldkeylen = 0;


enum nss_status
_nss_nis_sethostent (int stayopen)
{
  __libc_lock_lock (lock);

  new_start = 1;
  if (oldkey != NULL)
    {
      free (oldkey);
      oldkey = NULL;
      oldkeylen = 0;
    }

  __libc_lock_unlock (lock);

  return NSS_STATUS_SUCCESS;
}
/* Make _nss_nis_endhostent an alias of _nss_nis_sethostent.  We do this
   even though the prototypes don't match.  The argument of sethostent
   is used so this makes no difference.  */
strong_alias (_nss_nis_sethostent, _nss_nis_endhostent)


/* The calling function always need to get a lock first. */
static enum nss_status
internal_nis_gethostent_r (struct hostent *host, char *buffer,
			   size_t buflen, int *errnop, int *h_errnop,
			   int af, int flags)
{
  char *domain;
  if (__glibc_unlikely (yp_get_default_domain (&domain)))
    return NSS_STATUS_UNAVAIL;

  uintptr_t pad = -(uintptr_t) buffer % __alignof__ (struct parser_data);
  buffer += pad;

  struct parser_data *data = (void *) buffer;
  if (__glibc_unlikely (buflen < sizeof *data + 1 + pad))
    {
      *errnop = ERANGE;
      *h_errnop = NETDB_INTERNAL;
      return NSS_STATUS_TRYAGAIN;
    }
  buflen -= pad;

  /* Get the next entry until we found a correct one. */
  const size_t linebuflen = buffer + buflen - data->linebuffer;
  int parse_res;
  do
    {
      char *result;
      int len;
      char *outkey;
      int keylen;
      int yperr;
      if (new_start)
	yperr = yp_first (domain, "hosts.byname", &outkey, &keylen, &result,
			  &len);
      else
	yperr = yp_next (domain, "hosts.byname", oldkey, oldkeylen, &outkey,
			 &keylen, &result, &len);

      if (__glibc_unlikely (yperr != YPERR_SUCCESS))
	{
	  enum nss_status retval = yperr2nss (yperr);

	  switch (retval)
	    {
	    case NSS_STATUS_TRYAGAIN:
	      *errnop = errno;
	      *h_errnop = TRY_AGAIN;
	      break;
	    case NSS_STATUS_NOTFOUND:
	      *h_errnop = HOST_NOT_FOUND;
	      break;
	    default:
	      *h_errnop = NO_RECOVERY;
	      break;
	    }
	  return retval;
	}

      if (__glibc_unlikely ((size_t) (len + 1) > linebuflen))
	{
	  free (result);
	  *h_errnop = NETDB_INTERNAL;
	  *errnop = ERANGE;
	  return NSS_STATUS_TRYAGAIN;
	}

      char *p = strncpy (data->linebuffer, result, len);
      data->linebuffer[len] = '\0';
      while (isspace (*p))
	++p;
      free (result);

      parse_res = parse_line (p, host, data, buflen, errnop, af, flags);
      if (__glibc_unlikely (parse_res == -1))
	{
	  free (outkey);
	  *h_errnop = NETDB_INTERNAL;
	  *errnop = ERANGE;
	  return NSS_STATUS_TRYAGAIN;
	}
      free (oldkey);
      oldkey = outkey;
      oldkeylen = keylen;
      new_start = 0;
    }
  while (!parse_res);

  *h_errnop = NETDB_SUCCESS;
  return NSS_STATUS_SUCCESS;
}


enum nss_status
_nss_nis_gethostent_r (struct hostent *host, char *buffer, size_t buflen,
		       int *errnop, int *h_errnop)
{
  enum nss_status status;

  __libc_lock_lock (lock);

  status = internal_nis_gethostent_r (host, buffer, buflen, errnop, h_errnop,
			((_res.options & RES_USE_INET6) ? AF_INET6 : AF_INET),
			((_res.options & RES_USE_INET6) ? AI_V4MAPPED : 0 ));

  __libc_lock_unlock (lock);

  return status;
}


static enum nss_status
internal_gethostbyname2_r (const char *name, int af, struct hostent *host,
			   char *buffer, size_t buflen, int *errnop,
			   int *h_errnop, int flags)
{
  uintptr_t pad = -(uintptr_t) buffer % __alignof__ (struct parser_data);
  buffer += pad;

  struct parser_data *data = (void *) buffer;

  if (name == NULL)
    {
      *errnop = EINVAL;
      return NSS_STATUS_UNAVAIL;
    }

  char *domain;
  if (yp_get_default_domain (&domain))
    return NSS_STATUS_UNAVAIL;

  if (buflen < sizeof *data + 1 + pad)
    {
      *h_errnop = NETDB_INTERNAL;
      *errnop = ERANGE;
      return NSS_STATUS_TRYAGAIN;
    }
  buflen -= pad;

  /* Convert name to lowercase.  */
  size_t namlen = strlen (name);
  /* Limit name length to the maximum size of an RPC packet.  */
  if (namlen > UDPMSGSIZE)
    {
      *errnop = ERANGE;
      return NSS_STATUS_UNAVAIL;
    }

  char name2[namlen + 1];
  size_t i;

  for (i = 0; i < namlen; ++i)
    name2[i] = tolower (name[i]);
  name2[i] = '\0';

  char *result;
  int len;
  int yperr = yp_match (domain, "hosts.byname", name2, namlen, &result, &len);

  if (__glibc_unlikely (yperr != YPERR_SUCCESS))
    {
      enum nss_status retval = yperr2nss (yperr);

      if (retval == NSS_STATUS_TRYAGAIN)
	{
	  *h_errnop = TRY_AGAIN;
	  *errnop = errno;
	}
      if (retval == NSS_STATUS_NOTFOUND)
	*h_errnop = HOST_NOT_FOUND;
      return retval;
    }

  const size_t linebuflen = buffer + buflen - data->linebuffer;
  if (__glibc_unlikely ((size_t) (len + 1) > linebuflen))
    {
      free (result);
      *h_errnop = NETDB_INTERNAL;
      *errnop = ERANGE;
      return NSS_STATUS_TRYAGAIN;
    }

  char *p = strncpy (data->linebuffer, result, len);
  data->linebuffer[len] = '\0';
  while (isspace (*p))
    ++p;
  free (result);

  int parse_res = parse_line (p, host, data, buflen, errnop, af, flags);

  if (__glibc_unlikely (parse_res < 1 || host->h_addrtype != af))
    {
      if (parse_res == -1)
	{
	  *h_errnop = NETDB_INTERNAL;
	  return NSS_STATUS_TRYAGAIN;
	}
      else
	{
	  *h_errnop = HOST_NOT_FOUND;
	  return NSS_STATUS_NOTFOUND;
	}
    }

  *h_errnop = NETDB_SUCCESS;
  return NSS_STATUS_SUCCESS;
}


enum nss_status
_nss_nis_gethostbyname2_r (const char *name, int af, struct hostent *host,
			   char *buffer, size_t buflen, int *errnop,
			   int *h_errnop)
{
  if (af != AF_INET && af != AF_INET6)
    {
      *h_errnop = HOST_NOT_FOUND;
      return NSS_STATUS_NOTFOUND;
    }

  return internal_gethostbyname2_r (name, af, host, buffer, buflen, errnop,
				    h_errnop,
			((_res.options & RES_USE_INET6) ? AI_V4MAPPED : 0));
}


enum nss_status
_nss_nis_gethostbyname_r (const char *name, struct hostent *host, char *buffer,
			  size_t buflen, int *errnop, int *h_errnop)
{
  if (_res.options & RES_USE_INET6)
    {
      enum nss_status status;

      status = internal_gethostbyname2_r (name, AF_INET6, host, buffer, buflen,
					  errnop, h_errnop, AI_V4MAPPED);
      if (status == NSS_STATUS_SUCCESS)
	return status;
    }

  return internal_gethostbyname2_r (name, AF_INET, host, buffer, buflen,
				    errnop, h_errnop, 0);
}


enum nss_status
_nss_nis_gethostbyaddr_r (const void *addr, socklen_t addrlen, int af,
			  struct hostent *host, char *buffer, size_t buflen,
			  int *errnop, int *h_errnop)
{
  char *domain;
  if (__glibc_unlikely (yp_get_default_domain (&domain)))
    return NSS_STATUS_UNAVAIL;

  uintptr_t pad = -(uintptr_t) buffer % __alignof__ (struct parser_data);
  buffer += pad;

  struct parser_data *data = (void *) buffer;
  if (__glibc_unlikely (buflen < sizeof *data + 1 + pad))
    {
      *errnop = ERANGE;
      *h_errnop = NETDB_INTERNAL;
      return NSS_STATUS_TRYAGAIN;
    }
  buflen -= pad;

  char *buf = inet_ntoa (*(const struct in_addr *) addr);

  char *result;
  int len;
  int yperr = yp_match (domain, "hosts.byaddr", buf, strlen (buf), &result,
			&len);

  if (__glibc_unlikely (yperr != YPERR_SUCCESS))
    {
      enum nss_status retval = yperr2nss (yperr);

      if (retval == NSS_STATUS_TRYAGAIN)
	{
	  *h_errnop = TRY_AGAIN;
	  *errnop = errno;
	}
      else if (retval == NSS_STATUS_NOTFOUND)
	*h_errnop = HOST_NOT_FOUND;

      return retval;
    }

  const size_t linebuflen = buffer + buflen - data->linebuffer;
  if (__glibc_unlikely ((size_t) (len + 1) > linebuflen))
    {
      free (result);
      *errnop = ERANGE;
      *h_errnop = NETDB_INTERNAL;
      return NSS_STATUS_TRYAGAIN;
    }

  char *p = strncpy (data->linebuffer, result, len);
  data->linebuffer[len] = '\0';
  while (isspace (*p))
    ++p;
  free (result);

  int parse_res = parse_line (p, host, data, buflen, errnop, af,
			      ((_res.options & RES_USE_INET6)
			       ? AI_V4MAPPED : 0));
  if (__glibc_unlikely (parse_res < 1))
    {
      if (parse_res == -1)
	{
	  *h_errnop = NETDB_INTERNAL;
	  return NSS_STATUS_TRYAGAIN;
	}
      else
	{
	  *h_errnop = HOST_NOT_FOUND;
	  return NSS_STATUS_NOTFOUND;
	}
    }

  *h_errnop = NETDB_SUCCESS;
  return NSS_STATUS_SUCCESS;
}


enum nss_status
_nss_nis_gethostbyname4_r (const char *name, struct gaih_addrtuple **pat,
			   char *buffer, size_t buflen, int *errnop,
			   int *herrnop, int32_t *ttlp)
{
  char *domain;
  if (yp_get_default_domain (&domain))
    {
      *herrnop = NO_DATA;
      return NSS_STATUS_UNAVAIL;
    }

  /* Convert name to lowercase.  */
  size_t namlen = strlen (name);
  /* Limit name length to the maximum size of an RPC packet.  */
  if (namlen > UDPMSGSIZE)
    {
      *errnop = ERANGE;
      return NSS_STATUS_UNAVAIL;
    }

  char name2[namlen + 1];
  size_t i;

  for (i = 0; i < namlen; ++i)
    name2[i] = tolower (name[i]);
  name2[i] = '\0';

  char *result;
  int len;
  int yperr = yp_match (domain, "hosts.byname", name2, namlen, &result, &len);

  if (__glibc_unlikely (yperr != YPERR_SUCCESS))
    {
      enum nss_status retval = yperr2nss (yperr);

      if (retval == NSS_STATUS_TRYAGAIN)
	{
	  *herrnop = TRY_AGAIN;
	  *errnop = errno;
	}
      if (retval == NSS_STATUS_NOTFOUND)
	*herrnop = HOST_NOT_FOUND;
      return retval;
    }

  if (*pat == NULL)
    {
      uintptr_t pad = (-(uintptr_t) buffer
		       % __alignof__ (struct gaih_addrtuple));
      buffer += pad;
      buflen = buflen > pad ? buflen - pad : 0;

      if (__glibc_unlikely (buflen < sizeof (struct gaih_addrtuple)))
	{
	erange:
	  free (result);
	  *errnop = ERANGE;
	  *herrnop = NETDB_INTERNAL;
	  return NSS_STATUS_TRYAGAIN;
	}

      *pat = (struct gaih_addrtuple *) buffer;
      buffer += sizeof (struct gaih_addrtuple);
      buflen -= sizeof (struct gaih_addrtuple);
    }

  uintptr_t pad = -(uintptr_t) buffer % __alignof__ (struct parser_data);
  buffer += pad;

  struct parser_data *data = (void *) buffer;

  if (__glibc_unlikely (buflen < sizeof *data + 1 + pad))
    goto erange;
  buflen -= pad;

  struct hostent host;
  int parse_res = parse_line (result, &host, data, buflen, errnop, AF_UNSPEC,
			      0);
  if (__glibc_unlikely (parse_res < 1))
    {
      if (parse_res == -1)
	{
	  *herrnop = NETDB_INTERNAL;
	  return NSS_STATUS_TRYAGAIN;
	}
      else
	{
	  *herrnop = HOST_NOT_FOUND;
	  return NSS_STATUS_NOTFOUND;
	}
    }

  (*pat)->next = NULL;
  (*pat)->family = host.h_addrtype;
  memcpy ((*pat)->addr, host.h_addr_list[0], host.h_length);
  (*pat)->scopeid = 0;
  assert (host.h_addr_list[1] == NULL);

  /* Undo the alignment for parser_data.  */
  buffer -= pad;
  buflen += pad;

  size_t h_name_len = strlen (host.h_name) + 1;
  if (h_name_len >= buflen)
    goto erange;
  (*pat)->name = memcpy (buffer, host.h_name, h_name_len);

  free (result);

  return NSS_STATUS_SUCCESS;
}