summaryrefslogtreecommitdiff
path: root/inet/getnetgrent_r.c
blob: 62cdfda9cbbde7ab3ea0a09dde79c8d9a624cbb9 (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
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
/* Copyright (C) 1996-2014 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
   <http://www.gnu.org/licenses/>.  */

#include <assert.h>
#include <atomic.h>
#include <bits/libc-lock.h>
#include <errno.h>
#include <netdb.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include "netgroup.h"
#include "nsswitch.h"
#include <sysdep.h>
#include <nscd/nscd_proto.h>


/* Protect above variable against multiple uses at the same time.  */
__libc_lock_define_initialized (static, lock)

/* The whole information for the set/get/endnetgrent functions are
   kept in this structure.  */
static struct __netgrent dataset;

/* The lookup function for the first entry of this service.  */
extern int __nss_netgroup_lookup (service_user **nipp, const char *name,
				  void **fctp) internal_function;

/* Set up NIP to run through the services.  Return nonzero if there are no
   services (left).  */
static int
setup (void **fctp, service_user **nipp)
{
  /* Remember the first service_entry, it's always the same.  */
  static bool startp_initialized;
  static service_user *startp;
  int no_more;

  if (!startp_initialized)
    {
      /* Executing this more than once at the same time must yield the
	 same result every time.  So we need no locking.  */
      no_more = __nss_netgroup_lookup (nipp, "setnetgrent", fctp);
      startp = no_more ? (service_user *) -1 : *nipp;
#ifdef PTR_MANGLE
      PTR_MANGLE (startp);
#endif
      atomic_write_barrier ();
      startp_initialized = true;
    }
  else
    {
      service_user *nip = startp;
#ifdef PTR_DEMANGLE
      PTR_DEMANGLE (nip);
#endif
      if (nip == (service_user *) -1)
	/* No services at all.  */
	return 1;

      /* Reset to the beginning of the service list.  */
      *nipp = nip;
      /* Look up the first function.  */
      no_more = __nss_lookup (nipp, "setnetgrent", NULL, fctp);
    }
  return no_more;
}

/* Free used memory.  */
static void
free_memory (struct __netgrent *data)
{
  while (data->known_groups != NULL)
    {
      struct name_list *tmp = data->known_groups;
      data->known_groups = data->known_groups->next;
      free (tmp);
    }

  while (data->needed_groups != NULL)
    {
      struct name_list *tmp = data->needed_groups;
      data->needed_groups = data->needed_groups->next;
      free (tmp);
    }
}

static void
endnetgrent_hook (struct __netgrent *datap)
{
  enum nss_status (*endfct) (struct __netgrent *);

  if (datap->nip == NULL || datap->nip == (service_user *) -1l)
    return;

  endfct = __nss_lookup_function (datap->nip, "endnetgrent");
  if (endfct != NULL)
    (void) (*endfct) (datap);
  datap->nip = NULL;
}

static int
internal_function
__internal_setnetgrent_reuse (const char *group, struct __netgrent *datap,
			      int *errnop)
{
  union
  {
    enum nss_status (*f) (const char *, struct __netgrent *);
    void *ptr;
  } fct;
  enum nss_status status = NSS_STATUS_UNAVAIL;
  struct name_list *new_elem;

  /* Free data from previous service.  */
  endnetgrent_hook (datap);

  /* Cycle through all the services and run their setnetgrent functions.  */
  int no_more = setup (&fct.ptr, &datap->nip);
  while (! no_more)
    {
      assert (datap->data == NULL);

      /* Ignore status, we force check in `__nss_next2'.  */
      status = DL_CALL_FCT (*fct.f, (group, datap));

      service_user *old_nip = datap->nip;
      no_more = __nss_next2 (&datap->nip, "setnetgrent", NULL, &fct.ptr,
			     status, 0);

      if (status == NSS_STATUS_SUCCESS && ! no_more)
	{
	  enum nss_status (*endfct) (struct __netgrent *);

	  endfct = __nss_lookup_function (old_nip, "endnetgrent");
	  if (endfct != NULL)
	    (void) DL_CALL_FCT (*endfct, (datap));
	}
    }

  /* Add the current group to the list of known groups.  */
  size_t group_len = strlen (group) + 1;
  new_elem = (struct name_list *) malloc (sizeof (struct name_list)
					  + group_len);
  if (new_elem == NULL)
    {
      *errnop = errno;
      status = NSS_STATUS_TRYAGAIN;
    }
  else
    {
      new_elem->next = datap->known_groups;
      memcpy (new_elem->name, group, group_len);
      datap->known_groups = new_elem;
    }

  return status == NSS_STATUS_SUCCESS;
}

int
internal_function
__internal_setnetgrent (const char *group, struct __netgrent *datap)
{
  /* Free list of all netgroup names from last run.  */
  free_memory (datap);

  return __internal_setnetgrent_reuse (group, datap, &errno);
}
libc_hidden_def (__internal_setnetgrent)

static int
nscd_setnetgrent (const char *group)
{
#ifdef USE_NSCD
  if (__nss_not_use_nscd_netgroup > 0
      && ++__nss_not_use_nscd_netgroup > NSS_NSCD_RETRY)
    __nss_not_use_nscd_netgroup = 0;

  if (!__nss_not_use_nscd_netgroup
      && !__nss_database_custom[NSS_DBSIDX_netgroup])
    return __nscd_setnetgrent (group, &dataset);
#endif
  return -1;
}

int
setnetgrent (const char *group)
{
  int result;

  __libc_lock_lock (lock);

  result = nscd_setnetgrent (group);
  if (result < 0)
    result = __internal_setnetgrent (group, &dataset);

  __libc_lock_unlock (lock);

  return result;
}

void
internal_function
__internal_endnetgrent (struct __netgrent *datap)
{
  endnetgrent_hook (datap);
  /* Now free list of all netgroup names from last run.  */
  free_memory (datap);
}
libc_hidden_def (__internal_endnetgrent)


void
endnetgrent (void)
{
  __libc_lock_lock (lock);

  __internal_endnetgrent (&dataset);

  __libc_lock_unlock (lock);
}

#ifdef USE_NSCD
static enum nss_status
nscd_getnetgrent (struct __netgrent *datap, char *buffer, size_t buflen,
		  int *errnop)
{
  if (datap->cursor >= datap->data + datap->data_size)
    return NSS_STATUS_UNAVAIL;

  datap->type = triple_val;
  datap->val.triple.host = datap->cursor;
  datap->cursor = (char *) __rawmemchr (datap->cursor, '\0') + 1;
  datap->val.triple.user = datap->cursor;
  datap->cursor = (char *) __rawmemchr (datap->cursor, '\0') + 1;
  datap->val.triple.domain = datap->cursor;
  datap->cursor = (char *) __rawmemchr (datap->cursor, '\0') + 1;

  return NSS_STATUS_SUCCESS;
}
#endif

int
internal_function
__internal_getnetgrent_r (char **hostp, char **userp, char **domainp,
			  struct __netgrent *datap,
			  char *buffer, size_t buflen, int *errnop)
{
  enum nss_status (*fct) (struct __netgrent *, char *, size_t, int *);

  /* Initialize status to return if no more functions are found.  */
  enum nss_status status = NSS_STATUS_NOTFOUND;

  /* Run through available functions, starting with the same function last
     run.  We will repeat each function as long as it succeeds, and then go
     on to the next service action.  */
  int no_more = datap->nip == NULL;
  if (! no_more)
    {
#ifdef USE_NSCD
      /* This bogus function pointer is a special marker left by
         __nscd_setnetgrent to tell us to use the data it left
         before considering any modules.  */
      if (datap->nip == (service_user *) -1l)
	fct = nscd_getnetgrent;
      else
#endif
	{
	  fct = __nss_lookup_function (datap->nip, "getnetgrent_r");
	  no_more = fct == NULL;
	}
    }

  while (! no_more)
    {
      status = DL_CALL_FCT (*fct, (datap, buffer, buflen, &errno));

      if (status == NSS_STATUS_RETURN)
	{
	  /* This was the last one for this group.  Look at next group
	     if available.  */
	  int found = 0;
	  while (datap->needed_groups != NULL && ! found)
	    {
	      struct name_list *tmp = datap->needed_groups;
	      datap->needed_groups = datap->needed_groups->next;
	      tmp->next = datap->known_groups;
	      datap->known_groups = tmp;

	      found = __internal_setnetgrent_reuse (datap->known_groups->name,
						    datap, errnop);
	    }

	  if (found && datap->nip != NULL)
	    {
	      fct = __nss_lookup_function (datap->nip, "getnetgrent_r");
	      if (fct != NULL)
		continue;
	    }
	}
      else if (status == NSS_STATUS_SUCCESS && datap->type == group_val)
	{
	  /* The last entry was a name of another netgroup.  */
	  struct name_list *namep;

	  /* Ignore if we've seen the name before.  */
	  for (namep = datap->known_groups; namep != NULL;
	       namep = namep->next)
	    if (strcmp (datap->val.group, namep->name) == 0)
	      break;
	  if (namep == NULL)
	    for (namep = datap->needed_groups; namep != NULL;
		 namep = namep->next)
	      if (strcmp (datap->val.group, namep->name) == 0)
		break;
	  if (namep != NULL)
	    /* Really ignore.  */
	    continue;

	  size_t group_len = strlen (datap->val.group) + 1;
	  namep = (struct name_list *) malloc (sizeof (struct name_list)
					       + group_len);
	  if (namep == NULL)
	    /* We are out of memory.  */
	    status = NSS_STATUS_RETURN;
	  else
	    {
	      namep->next = datap->needed_groups;
	      memcpy (namep->name, datap->val.group, group_len);
	      datap->needed_groups = namep;
	      /* And get the next entry.  */
	      continue;
	    }
	}

      break;
    }

  if (status == NSS_STATUS_SUCCESS)
    {
      *hostp = (char *) datap->val.triple.host;
      *userp = (char *) datap->val.triple.user;
      *domainp = (char *) datap->val.triple.domain;
    }

  return status == NSS_STATUS_SUCCESS ? 1 : 0;
}
libc_hidden_def (__internal_getnetgrent_r)

/* The real entry point.  */
int
__getnetgrent_r (char **hostp, char **userp, char **domainp,
		 char *buffer, size_t buflen)
{
  enum nss_status status;

  __libc_lock_lock (lock);

  status = __internal_getnetgrent_r (hostp, userp, domainp, &dataset,
                                     buffer, buflen, &errno);

  __libc_lock_unlock (lock);

  return status;
}
weak_alias (__getnetgrent_r, getnetgrent_r)

/* Test whether given (host,user,domain) triple is in NETGROUP.  */
int
innetgr (const char *netgroup, const char *host, const char *user,
	 const char *domain)
{
#ifdef USE_NSCD
  if (__nss_not_use_nscd_netgroup > 0
      && ++__nss_not_use_nscd_netgroup > NSS_NSCD_RETRY)
    __nss_not_use_nscd_netgroup = 0;

  if (!__nss_not_use_nscd_netgroup
      && !__nss_database_custom[NSS_DBSIDX_netgroup])
    {
      int result = __nscd_innetgr (netgroup, host, user, domain);
      if (result >= 0)
	return result;
    }
#endif

  union
  {
    enum nss_status (*f) (const char *, struct __netgrent *);
    void *ptr;
  } setfct;
  void (*endfct) (struct __netgrent *);
  int (*getfct) (struct __netgrent *, char *, size_t, int *);
  struct __netgrent entry;
  int result = 0;
  const char *current_group = netgroup;

  memset (&entry, '\0', sizeof (entry));

  /* Walk through the services until we found an answer or we shall
     not work further.  We can do some optimization here.  Since all
     services must provide the `setnetgrent' function we can do all
     the work during one walk through the service list.  */
  while (1)
    {
      int no_more = setup (&setfct.ptr, &entry.nip);
      while (! no_more)
	{
	  assert (entry.data == NULL);

	  /* Open netgroup.  */
	  enum nss_status status = DL_CALL_FCT (*setfct.f,
						(current_group, &entry));

	  if (status == NSS_STATUS_SUCCESS
	      && (getfct = __nss_lookup_function (entry.nip, "getnetgrent_r"))
		 != NULL)
	    {
	      char buffer[1024];

	      while (DL_CALL_FCT (*getfct,
				  (&entry, buffer, sizeof buffer, &errno))
		     == NSS_STATUS_SUCCESS)
		{
		  if (entry.type == group_val)
		    {
		      /* Make sure we haven't seen the name before.  */
		      struct name_list *namep;

		      for (namep = entry.known_groups; namep != NULL;
			   namep = namep->next)
			if (strcmp (entry.val.group, namep->name) == 0)
			  break;
		      if (namep == NULL)
			for (namep = entry.needed_groups; namep != NULL;
			     namep = namep->next)
			  if (strcmp (entry.val.group, namep->name) == 0)
			    break;
		      if (namep == NULL
			  && strcmp (netgroup, entry.val.group) != 0)
			{
			  size_t group_len = strlen (entry.val.group) + 1;
			  namep =
			    (struct name_list *) malloc (sizeof (*namep)
							 + group_len);
			  if (namep == NULL)
			    {
			      /* Out of memory, simply return.  */
			      result = -1;
			      break;
			    }

			  namep->next = entry.needed_groups;
			  memcpy (namep->name, entry.val.group, group_len);
			  entry.needed_groups = namep;
			}
		    }
		  else
		    {
		      if ((entry.val.triple.host == NULL || host == NULL
			   || __strcasecmp (entry.val.triple.host, host) == 0)
			  && (entry.val.triple.user == NULL || user == NULL
			      || strcmp (entry.val.triple.user, user) == 0)
			  && (entry.val.triple.domain == NULL || domain == NULL
			      || __strcasecmp (entry.val.triple.domain,
					       domain) == 0))
			{
			  result = 1;
			  break;
			}
		    }
		}

	      /* If we found one service which does know the given
		 netgroup we don't try further.  */
	      status = NSS_STATUS_RETURN;
	    }

	  /* Free all resources of the service.  */
	  endfct = __nss_lookup_function (entry.nip, "endnetgrent");
	  if (endfct != NULL)
	    DL_CALL_FCT (*endfct, (&entry));

	  if (result != 0)
	    break;

	  /* Look for the next service.  */
	  no_more = __nss_next2 (&entry.nip, "setnetgrent", NULL,
				 &setfct.ptr, status, 0);
	}

      if (result == 0 && entry.needed_groups != NULL)
	{
	  struct name_list *tmp = entry.needed_groups;
	  entry.needed_groups = tmp->next;
	  tmp->next = entry.known_groups;
	  entry.known_groups = tmp;
	  current_group = tmp->name;
	  continue;
	}

      /* No way out.  */
      break;
    }

  /* Free the memory.  */
  free_memory (&entry);

  return result == 1;
}
libc_hidden_def (innetgr)