about summary refs log tree commit diff
path: root/nis/nss_nis/nis-pwd.c
blob: 89de350c4dab47d48d073a5a1f3d2231af9c9973 (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
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
/* Copyright (C) 1996-1998,2001-2003,2006,2009,2010
   Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Thorsten Kukuk <kukuk@vt.uni-paderborn.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, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#include <assert.h>
#include <ctype.h>
#include <errno.h>
#include <nss.h>
#include <pwd.h>
#include <string.h>
#include <bits/libc-lock.h>
#include <rpcsvc/yp.h>
#include <rpcsvc/ypclnt.h>

#include "nss-nis.h"
#include <libnsl.h>

/* Get the declaration of the parser function.  */
#define ENTNAME pwent
#define STRUCTURE passwd
#define EXTERN_PARSER
#include <nss/nss_files/files-parse.c>

/* Protect global state against multiple changers */
__libc_lock_define_initialized (static, lock)

static bool new_start = true;
static char *oldkey;
static int oldkeylen;
static intern_t intern;


int
_nis_saveit (int instatus, char *inkey, int inkeylen, char *inval,
	     int invallen, char *indata)
{
  intern_t *intern = (intern_t *) indata;

  if (instatus != YP_TRUE)
    return 1;

  if (inkey && inkeylen > 0 && inval && invallen > 0)
    {
      struct response_t *bucket = intern->next;

      if (__builtin_expect (bucket == NULL, 0))
	{
#define MINSIZE 4096 - 4 * sizeof (void *)
	  const size_t minsize = MAX (MINSIZE, 2 * (invallen + 1));
	  bucket = malloc (sizeof (struct response_t) + minsize);
	  if (bucket == NULL)
	    /* We have no error code for out of memory.  */
	    return 1;

	  bucket->next = NULL;
	  bucket->size = minsize;
	  intern->start = intern->next = bucket;
	  intern->offset = 0;
	}
      else if (__builtin_expect (invallen + 1 > bucket->size - intern->offset,
				 0))
	{
	  /* We need a new (larger) buffer.  */
	  const size_t newsize = 2 * MAX (bucket->size, invallen + 1);
	  struct response_t *newp = malloc (sizeof (struct response_t)
					    + newsize);
	  if (newp == NULL)
	    /* We have no error code for out of memory.  */
	    return 1;

	  /* Mark the old bucket as full.  */
	  bucket->size = intern->offset;

	  newp->next = NULL;
	  newp->size = newsize;
	  bucket = intern->next = bucket->next = newp;
	  intern->offset = 0;
	}

      char *p = mempcpy (&bucket->mem[intern->offset], inval, invallen);
      if (__builtin_expect (p[-1] != '\0', 0))
	{
	  *p = '\0';
	  ++invallen;
	}
      intern->offset += invallen;
    }

  return 0;
}


static void
internal_nis_endpwent (void)
{
  new_start = true;
  free (oldkey);
  oldkey = NULL;
  oldkeylen = 0;

  struct response_t *curr = intern.start;

  while (curr != NULL)
    {
      struct response_t *last = curr;
      curr = curr->next;
      free (last);
    }

  intern.next = intern.start = NULL;
}


enum nss_status
_nss_nis_endpwent (void)
{
  __libc_lock_lock (lock);

  internal_nis_endpwent ();

  __libc_lock_unlock (lock);

  return NSS_STATUS_SUCCESS;
}


enum nss_status
internal_nis_setpwent (void)
{
  /* We have to read all the data now.  */
  char *domain;
  if (__builtin_expect (yp_get_default_domain (&domain), 0))
    return NSS_STATUS_UNAVAIL;

  struct ypall_callback ypcb;

  ypcb.foreach = _nis_saveit;
  ypcb.data = (char *) &intern;
  enum nss_status status = yperr2nss (yp_all (domain, "passwd.byname", &ypcb));


  /* Mark the last buffer as full.  */
  if (intern.next != NULL)
    intern.next->size = intern.offset;

  intern.next = intern.start;
  intern.offset = 0;

  return status;
}


enum nss_status
_nss_nis_setpwent (int stayopen)
{
  enum nss_status result = NSS_STATUS_SUCCESS;

  __libc_lock_lock (lock);

  internal_nis_endpwent ();

  if (_nsl_default_nss () & NSS_FLAG_SETENT_BATCH_READ)
    result = internal_nis_setpwent ();

  __libc_lock_unlock (lock);

  return result;
}


static enum nss_status
internal_nis_getpwent_r (struct passwd *pwd, char *buffer, size_t buflen,
			 int *errnop)
{
  /* If we read the entire database at setpwent time we just iterate
     over the data we have in memory.  */
  bool batch_read = intern.start != NULL;

  char *domain = NULL;
  if (!batch_read && __builtin_expect (yp_get_default_domain (&domain), 0))
    return NSS_STATUS_UNAVAIL;

  /* Get the next entry until we found a correct one. */
  int parse_res;
  do
    {
      char *result;
      char *outkey;
      int len;
      int keylen;

      if (batch_read)
	{
	  struct response_t *bucket;

	handle_batch_read:
	  bucket = intern.next;

	  if (__builtin_expect (intern.offset >= bucket->size, 0))
	    {
	      if (bucket->next == NULL)
		return NSS_STATUS_NOTFOUND;

	      /* We look at all the content in the current bucket.  Go on
		 to the next.  */
	      bucket = intern.next = bucket->next;
	      intern.offset = 0;
	    }

	  for (result = &bucket->mem[intern.offset]; isspace (*result);
	       ++result)
	    ++intern.offset;

	  len = strlen (result);
	}
      else
	{
	  int yperr;

	  if (new_start)
	    {
	      /* Maybe we should read the database in one piece.  */
	      if ((_nsl_default_nss () & NSS_FLAG_SETENT_BATCH_READ)
		  && internal_nis_setpwent () == NSS_STATUS_SUCCESS
		  && intern.start != NULL)
		{
		  batch_read = true;
		  goto handle_batch_read;
		}

	      yperr = yp_first (domain, "passwd.byname", &outkey, &keylen,
				&result, &len);
	    }
	  else
	    yperr = yp_next (domain, "passwd.byname", oldkey, oldkeylen,
			     &outkey, &keylen, &result, &len);

	  if (__builtin_expect (yperr != YPERR_SUCCESS, 0))
	    {
	      enum nss_status retval = yperr2nss (yperr);

	      if (retval == NSS_STATUS_TRYAGAIN)
		*errnop = errno;
	      return retval;
	    }
	}

      /* Check for adjunct style secret passwords.  They can be
	 recognized by a password starting with "##".  We do not use
	 it if the passwd.adjunct.byname table is supposed to be used
	 as a shadow.byname replacement.  */
      char *p = strchr (result, ':');
      size_t namelen;
      char *result2;
      int len2;
      if ((_nsl_default_nss () & NSS_FLAG_ADJUNCT_AS_SHADOW) == 0
	  && p != NULL	/* This better should be true in all cases.  */
	  && p[1] == '#' && p[2] == '#'
	  && (namelen = p - result,
	      yp_match (domain, "passwd.adjunct.byname", result, namelen,
			&result2, &len2)) == YPERR_SUCCESS)
	{
	  /* We found a passwd.adjunct.byname entry.  Merge encrypted
	     password therein into original result.  */
	  char *encrypted = strchr (result2, ':');
	  char *endp;
	  size_t restlen;

	  if (encrypted == NULL
	      || (endp = strchr (++encrypted, ':')) == NULL
	      || (p = strchr (p + 1, ':')) == NULL)
	    {
	      /* Invalid format of the entry.  This never should happen
		 unless the data from which the NIS table is generated is
		 wrong.  We simply ignore it.  */
	      free (result2);
	      goto non_adjunct;
	    }

	  restlen = len - (p - result);
	  if (__builtin_expect ((size_t) (namelen + (endp - encrypted)
					  + restlen + 2) > buflen, 0))
	    {
	      free (result2);
	      free (result);
	      *errnop = ERANGE;
	      return NSS_STATUS_TRYAGAIN;
	    }

	  mempcpy (mempcpy (mempcpy (mempcpy (buffer, result, namelen),
				     ":", 1),
			    encrypted, endp - encrypted),
		   p, restlen + 1);
	  p = buffer;

	  free (result2);
	}
      else
	{
	non_adjunct:
	  if (__builtin_expect ((size_t) (len + 1) > buflen, 0))
	    {
	      free (result);
	      *errnop = ERANGE;
	      return NSS_STATUS_TRYAGAIN;
	    }

	  p = buffer;
	  *((char *) mempcpy (buffer, result, len)) = '\0';
	}

      while (isspace (*p))
	++p;
      if (!batch_read)
	free (result);

      parse_res = _nss_files_parse_pwent (p, pwd, (void *) buffer, buflen,
					  errnop);
      if (__builtin_expect (parse_res == -1, 0))
	{
	  if (!batch_read)
	    free (outkey);
	  *errnop = ERANGE;
	  return NSS_STATUS_TRYAGAIN;
	}

      if (batch_read)
	intern.offset += len + 1;
      else
	{
	  free (oldkey);
	  oldkey = outkey;
	  oldkeylen = keylen;
	  new_start = false;
	}
    }
  while (parse_res < 1);

  return NSS_STATUS_SUCCESS;
}

enum nss_status
_nss_nis_getpwent_r (struct passwd *result, char *buffer, size_t buflen,
		     int *errnop)
{
  int status;

  __libc_lock_lock (lock);

  status = internal_nis_getpwent_r (result, buffer, buflen, errnop);

  __libc_lock_unlock (lock);

  return status;
}

enum nss_status
_nss_nis_getpwnam_r (const char *name, struct passwd *pwd,
		     char *buffer, size_t buflen, int *errnop)
{
  if (name == NULL)
    {
      *errnop = EINVAL;
      return NSS_STATUS_UNAVAIL;
    }

  char *domain;
  if (__builtin_expect (yp_get_default_domain (&domain), 0))
    return NSS_STATUS_UNAVAIL;

  size_t namelen = strlen (name);

  char *result;
  int len;
  int yperr = yp_match (domain, "passwd.byname", name, namelen, &result, &len);

  if (__builtin_expect (yperr != YPERR_SUCCESS, 0))
    {
      enum nss_status retval = yperr2nss (yperr);

      if (retval == NSS_STATUS_TRYAGAIN)
	*errnop = errno;
      return retval;
    }

  /* Check for adjunct style secret passwords.  They can be recognized
     by a password starting with "##". We do not use it if the
     passwd.adjunct.byname table is supposed to be used as a shadow.byname
     replacement.  */
  char *result2;
  int len2;
  char *p = strchr (result, ':');
  if ((_nsl_default_nss () & NSS_FLAG_ADJUNCT_AS_SHADOW) == 0
      && p != NULL	/* This better should be true in all cases.  */
      && p[1] == '#' && p[2] == '#'
      && yp_match (domain, "passwd.adjunct.byname", name, namelen,
		   &result2, &len2) == YPERR_SUCCESS)
    {
      /* We found a passwd.adjunct.byname entry.  Merge encrypted password
	 therein into original result.  */
      char *encrypted = strchr (result2, ':');
      char *endp;

      if (encrypted == NULL
	  || (endp = strchr (++encrypted, ':')) == NULL
	  || (p = strchr (p + 1, ':')) == NULL)
	{
	  /* Invalid format of the entry.  This never should happen
	     unless the data from which the NIS table is generated is
	     wrong.  We simply ignore it.  */
	  free (result2);
	  goto non_adjunct;
	}

      size_t restlen = len - (p - result);
      if (__builtin_expect ((size_t) (namelen + (endp - encrypted)
				      + restlen + 2) > buflen, 0))
	{
	  free (result2);
	  free (result);
	  *errnop = ERANGE;
	  return NSS_STATUS_TRYAGAIN;
	}

      __mempcpy (__mempcpy (__mempcpy (__mempcpy (buffer, name, namelen),
				       ":", 1),
			    encrypted, endp - encrypted),
		 p, restlen + 1);
      p = buffer;

      free (result2);
    }
  else
    {
    non_adjunct:
      if (__builtin_expect ((size_t) (len + 1) > buflen, 0))
	{
	  free (result);
	  *errnop = ERANGE;
	  return NSS_STATUS_TRYAGAIN;
	}

      p = strncpy (buffer, result, len);
      buffer[len] = '\0';
    }

  while (isspace (*p))
    ++p;
  free (result);

  int parse_res = _nss_files_parse_pwent (p, pwd, (void *) buffer, buflen,
					  errnop);
  if (__builtin_expect (parse_res < 1, 0))
    {
      if (parse_res == -1)
	return NSS_STATUS_TRYAGAIN;
      else
	return NSS_STATUS_NOTFOUND;
    }
  else
    return NSS_STATUS_SUCCESS;
}

enum nss_status
_nss_nis_getpwuid_r (uid_t uid, struct passwd *pwd,
		     char *buffer, size_t buflen, int *errnop)
{
  char *domain;
  if (__builtin_expect (yp_get_default_domain (&domain), 0))
    return NSS_STATUS_UNAVAIL;

  char buf[32];
  int nlen = snprintf (buf, sizeof (buf), "%lu", (unsigned long int) uid);

  char *result;
  int len;
  int yperr = yp_match (domain, "passwd.byuid", buf, nlen, &result, &len);

  if (__builtin_expect (yperr != YPERR_SUCCESS, 0))
    {
      enum nss_status retval = yperr2nss (yperr);

      if (retval == NSS_STATUS_TRYAGAIN)
	*errnop = errno;
      return retval;
    }

  /* Check for adjunct style secret passwords.  They can be recognized
     by a password starting with "##".  We do not use it if the
     passwd.adjunct.byname table is supposed to be used as a shadow.byname
     replacement.  */
  char *result2;
  int len2;
  size_t namelen;
  char *p = strchr (result, ':');
  if ((_nsl_default_nss () & NSS_FLAG_ADJUNCT_AS_SHADOW) == 0
      && p != NULL	/* This better should be true in all cases.  */
      && p[1] == '#' && p[2] == '#'
      && (namelen = p - result,
	  yp_match (domain, "passwd.adjunct.byname", result, namelen,
		    &result2, &len2)) == YPERR_SUCCESS)
    {
      /* We found a passwd.adjunct.byname entry.  Merge encrypted password
	 therein into original result.  */
      char *encrypted = strchr (result2, ':');
      char *endp;
      size_t restlen;

      if (encrypted == NULL
	  || (endp = strchr (++encrypted, ':')) == NULL
	  || (p = strchr (p + 1, ':')) == NULL)
	{
	  /* Invalid format of the entry.  This never should happen
	     unless the data from which the NIS table is generated is
	     wrong.  We simply ignore it.  */
	  free (result2);
	  goto non_adjunct;
	}

      restlen = len - (p - result);
      if (__builtin_expect ((size_t) (namelen + (endp - encrypted)
				      + restlen + 2) > buflen, 0))
	{
	  free (result2);
	  free (result);
	  *errnop = ERANGE;
	  return NSS_STATUS_TRYAGAIN;
	}

      __mempcpy (__mempcpy (__mempcpy (__mempcpy (buffer, result, namelen),
				       ":", 1),
			    encrypted, endp - encrypted),
		 p, restlen + 1);
      p = buffer;

      free (result2);
    }
  else
    {
    non_adjunct:
      if (__builtin_expect ((size_t) (len + 1) > buflen, 0))
	{
	  free (result);
	  *errnop = ERANGE;
	  return NSS_STATUS_TRYAGAIN;
	}

      p = strncpy (buffer, result, len);
      buffer[len] = '\0';
    }

  while (isspace (*p))
    ++p;
  free (result);

  int parse_res = _nss_files_parse_pwent (p, pwd, (void *) buffer, buflen,
					  errnop);
  if (__builtin_expect (parse_res < 1, 0))
    {
      if (parse_res == -1)
	return NSS_STATUS_TRYAGAIN;
     else
       return NSS_STATUS_NOTFOUND;
    }
  else
    return NSS_STATUS_SUCCESS;
}