summaryrefslogtreecommitdiff
path: root/nis/nis_call.c
blob: 1684de1c6dfd672a943193d7a6d99807ea4d431f (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
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
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
/* Copyright (C) 1997-2019 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Thorsten Kukuk <kukuk@vt.uni-paderborn.de>, 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
   <https://www.gnu.org/licenses/>.  */

#include <errno.h>
#include <fcntl.h>
#include <string.h>
#include <libintl.h>
#include <rpc/rpc.h>
#include <rpc/auth.h>
#include <rpcsvc/nis.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <unistd.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <libc-lock.h>

#include "nis_xdr.h"
#include "nis_intern.h"
#include <libnsl.h>
#include <shlib-compat.h>

static const struct timeval RPCTIMEOUT = {10, 0};
static const struct timeval UDPTIMEOUT = {5, 0};

extern u_short __pmap_getnisport (struct sockaddr_in *address, u_long program,
				  u_long version, u_int protocol);

unsigned long int
inetstr2int (const char *str)
{
  size_t j = 0;
  for (size_t i = 0; str[i] != '\0'; ++i)
    if (str[i] == '.' && __builtin_expect (++j == 4, 0))
      {
	char buffer[i + 1];
	buffer[i] = '\0';
	return inet_addr (memcpy (buffer, str, i));
      }

  return inet_addr (str);
}

void
__nisbind_destroy (dir_binding *bind)
{
  if (bind->clnt != NULL)
    {
      if (bind->use_auth)
	auth_destroy (bind->clnt->cl_auth);
      clnt_destroy (bind->clnt);
    }
}
libnsl_hidden_nolink_def (__nisbind_destroy, GLIBC_2_1)

nis_error
__nisbind_next (dir_binding *bind)
{
  if (bind->clnt != NULL)
    {
      if (bind->use_auth)
	auth_destroy (bind->clnt->cl_auth);
      clnt_destroy (bind->clnt);
      bind->clnt = NULL;
    }

  if (bind->trys >= bind->server_len)
    return NIS_FAIL;

  for (u_int j = bind->current_ep + 1;
       j < bind->server_val[bind->server_used].ep.ep_len; ++j)
    if (strcmp (bind->server_val[bind->server_used].ep.ep_val[j].family,
		"inet") == 0)
      if (bind->server_val[bind->server_used].ep.ep_val[j].proto[0] == '-')
	{
	  bind->current_ep = j;
	  return NIS_SUCCESS;
	}

  ++bind->trys;
  ++bind->server_used;
  if (bind->server_used >= bind->server_len)
    bind->server_used = 0;

  for (u_int j = 0; j < bind->server_val[bind->server_used].ep.ep_len; ++j)
    if (strcmp (bind->server_val[bind->server_used].ep.ep_val[j].family,
		"inet") == 0)
      if (bind->server_val[bind->server_used].ep.ep_val[j].proto[0] == '-')
	{
	  bind->current_ep = j;
	  return NIS_SUCCESS;
	}

  return NIS_FAIL;
}
libnsl_hidden_nolink_def (__nisbind_next, GLIBC_2_1)

static struct ckey_cache_entry
{
  struct in_addr inaddr;
  in_port_t port;
  unsigned int protocol;
  des_block ckey;
} *ckey_cache;
static size_t ckey_cache_size;
static size_t ckey_cache_allocated;
static pid_t ckey_cache_pid;
static uid_t ckey_cache_euid;
__libc_lock_define_initialized (static, ckey_cache_lock)

static bool_t
get_ckey (des_block *ckey, struct sockaddr_in *addr, unsigned int protocol)
{
  size_t i;
  pid_t pid = getpid ();
  uid_t euid = geteuid ();
  bool_t ret = FALSE;

  __libc_lock_lock (ckey_cache_lock);

  if (ckey_cache_pid != pid || ckey_cache_euid != euid)
    {
      ckey_cache_size = 0;
      ckey_cache_pid = pid;
      ckey_cache_euid = euid;
    }

  for (i = 0; i < ckey_cache_size; ++i)
    if (ckey_cache[i].port == addr->sin_port
	&& ckey_cache[i].protocol == protocol
	&& memcmp (&ckey_cache[i].inaddr, &addr->sin_addr,
		   sizeof (addr->sin_addr)) == 0)
      {
	*ckey = ckey_cache[i].ckey;
	ret = TRUE;
	break;
      }

  if (!ret && key_gendes (ckey) >= 0)
    {
      ret = TRUE;
      /* Don't grow the cache indefinitely.  */
      if (ckey_cache_size == 256)
	ckey_cache_size = 0;
      if (ckey_cache_size == ckey_cache_allocated)
	{
	  size_t size = ckey_cache_allocated ? ckey_cache_allocated * 2 : 16;
	  struct ckey_cache_entry *new_cache
	    = realloc (ckey_cache, size * sizeof (*ckey_cache));
	  if (new_cache != NULL)
	    {
	      ckey_cache = new_cache;
	      ckey_cache_allocated = size;
	    }
	}
      ckey_cache[ckey_cache_size].inaddr = addr->sin_addr;
      ckey_cache[ckey_cache_size].port = addr->sin_port;
      ckey_cache[ckey_cache_size].protocol = protocol;
      ckey_cache[ckey_cache_size++].ckey = *ckey;
    }

  __libc_lock_unlock (ckey_cache_lock);
  return ret;
}

nis_error
__nisbind_connect (dir_binding *dbp)
{
  nis_server *serv;
  u_short port;

  if (dbp == NULL)
    return NIS_FAIL;

  serv = &dbp->server_val[dbp->server_used];

  memset (&dbp->addr, '\0', sizeof (dbp->addr));
  dbp->addr.sin_family = AF_INET;

  dbp->addr.sin_addr.s_addr =
    inetstr2int (serv->ep.ep_val[dbp->current_ep].uaddr);

  if (dbp->addr.sin_addr.s_addr == INADDR_NONE)
    return NIS_FAIL;

  /* Check, if the host is online and rpc.nisd is running. Much faster
     then the clnt*_create functions: */
  port = __pmap_getnisport (&dbp->addr, NIS_PROG, NIS_VERSION,
			    dbp->use_udp ? IPPROTO_UDP : IPPROTO_TCP);
  if (port == 0)
    return NIS_RPCERROR;

  dbp->addr.sin_port = htons (port);
  dbp->socket = RPC_ANYSOCK;
  if (dbp->use_udp)
    dbp->clnt = clntudp_create (&dbp->addr, NIS_PROG, NIS_VERSION,
				 UDPTIMEOUT, &dbp->socket);
  else
    dbp->clnt = clnttcp_create (&dbp->addr, NIS_PROG, NIS_VERSION,
				 &dbp->socket, 0, 0);

  if (dbp->clnt == NULL)
    return NIS_RPCERROR;

  clnt_control (dbp->clnt, CLSET_TIMEOUT, (caddr_t) &RPCTIMEOUT);
  /* If the program exists, close the socket */
  if (fcntl (dbp->socket, F_SETFD, 1) == -1)
    perror ("fcntl: F_SETFD");

  if (dbp->use_auth)
    {
      if (serv->key_type == NIS_PK_DH)
	{
	  char netname[MAXNETNAMELEN + 1];
	  char *p;
	  des_block ckey;

	  p = stpcpy (netname, "unix@");
	  strncpy (p, serv->name, MAXNETNAMELEN - 5);
	  netname[MAXNETNAMELEN] = '\0';
	  dbp->clnt->cl_auth = NULL;
	  if (get_ckey (&ckey, &dbp->addr,
			dbp->use_udp ? IPPROTO_UDP : IPPROTO_TCP))
	    dbp->clnt->cl_auth =
	      authdes_pk_create (netname, &serv->pkey, 300, NULL, &ckey);
	  if (!dbp->clnt->cl_auth)
	    dbp->clnt->cl_auth = authunix_create_default ();
	}
      else
	dbp->clnt->cl_auth = authunix_create_default ();
    }

  return NIS_SUCCESS;
}
libnsl_hidden_nolink_def (__nisbind_connect, GLIBC_2_1)

nis_error
__nisbind_create (dir_binding *dbp, const nis_server *serv_val,
		  unsigned int serv_len, unsigned int server_used,
		  unsigned int current_ep, unsigned int flags)
{
  dbp->clnt = NULL;

  dbp->server_len = serv_len;
  dbp->server_val = (nis_server *)serv_val;

  if (flags & USE_DGRAM)
    dbp->use_udp = TRUE;
  else
    dbp->use_udp = FALSE;

  if (flags & NO_AUTHINFO)
    dbp->use_auth = FALSE;
  else
    dbp->use_auth = TRUE;

  if (flags & MASTER_ONLY)
    dbp->master_only = TRUE;
  else
    dbp->master_only = FALSE;

  /* We try the first server */
  dbp->trys = 1;

  dbp->class = -1;
  if (server_used == ~0)
    {
      if (__nis_findfastest (dbp) < 1)
	return NIS_NAMEUNREACHABLE;
    }
  else
    {
      dbp->server_used = server_used;
      dbp->current_ep = current_ep;
    }

  return NIS_SUCCESS;
}
libnsl_hidden_nolink_def (__nisbind_create, GLIBC_2_1)

/* __nisbind_connect (dbp) must be run before calling this function !
   So we could use the same binding twice */
nis_error
__do_niscall3 (dir_binding *dbp, u_long prog, xdrproc_t xargs, caddr_t req,
	       xdrproc_t xres, caddr_t resp, unsigned int flags, nis_cb *cb)
{
  enum clnt_stat result;
  nis_error retcode;

  if (dbp == NULL)
    return NIS_NAMEUNREACHABLE;

  do
    {
    again:
      result = clnt_call (dbp->clnt, prog, xargs, req, xres, resp, RPCTIMEOUT);

      if (result != RPC_SUCCESS)
	retcode = NIS_RPCERROR;
      else
	{
	  switch (prog)
	    {
	    case NIS_IBLIST:
	      if ((((nis_result *)resp)->status == NIS_CBRESULTS)
		  && (cb != NULL))
		{
		  __nis_do_callback (dbp, &((nis_result *) resp)->cookie, cb);
		  break;
		}
	      /* Yes, the missing break is correct. If we doesn't have to
		 start a callback, look if we have to search another server */
	      /* Fall through.  */
	    case NIS_LOOKUP:
	    case NIS_ADD:
	    case NIS_MODIFY:
	    case NIS_REMOVE:
	    case NIS_IBADD:
	    case NIS_IBMODIFY:
	    case NIS_IBREMOVE:
	    case NIS_IBFIRST:
	    case NIS_IBNEXT:
	      if (((nis_result *)resp)->status == NIS_SYSTEMERROR
		  || ((nis_result *)resp)->status == NIS_NOSUCHNAME
		  || ((nis_result *)resp)->status == NIS_NOT_ME)
		{
		next_server:
		  if (__nisbind_next (dbp) == NIS_SUCCESS)
		    {
		      while (__nisbind_connect (dbp) != NIS_SUCCESS)
			{
			  if (__nisbind_next (dbp) != NIS_SUCCESS)
			      return NIS_SUCCESS;
			}
		    }
		  else
		    break; /* No more servers to search in */
		  goto again;
		}
	      break;
	    case NIS_FINDDIRECTORY:
	      if (((fd_result *)resp)->status == NIS_SYSTEMERROR
		  || ((fd_result *)resp)->status == NIS_NOSUCHNAME
		  || ((fd_result *)resp)->status == NIS_NOT_ME)
		goto next_server;
	      break;
	    case NIS_DUMPLOG: /* log_result */
	    case NIS_DUMP:
	      if (((log_result *)resp)->lr_status == NIS_SYSTEMERROR
		  || ((log_result *)resp)->lr_status == NIS_NOSUCHNAME
		  || ((log_result *)resp)->lr_status == NIS_NOT_ME)
		goto next_server;
	      break;
	    default:
	      break;
	    }
	  retcode = NIS_SUCCESS;
	}
    }
  while ((flags & HARD_LOOKUP) && retcode == NIS_RPCERROR);

  return retcode;
}
libnsl_hidden_nolink_def (__do_niscall3, GLIBC_PRIVATE)


nis_error
__do_niscall2 (const nis_server *server, u_int server_len, u_long prog,
	       xdrproc_t xargs, caddr_t req, xdrproc_t xres, caddr_t resp,
	       unsigned int flags, nis_cb *cb)
{
  dir_binding dbp;
  nis_error status;

  if (flags & MASTER_ONLY)
    server_len = 1;

  status = __nisbind_create (&dbp, server, server_len, ~0, ~0, flags);
  if (status != NIS_SUCCESS)
    return status;

  while (__nisbind_connect (&dbp) != NIS_SUCCESS)
    if (__nisbind_next (&dbp) != NIS_SUCCESS)
      return NIS_NAMEUNREACHABLE;

  status = __do_niscall3 (&dbp, prog, xargs, req, xres, resp, flags, cb);

  __nisbind_destroy (&dbp);

  return status;

}

static directory_obj *
rec_dirsearch (const_nis_name name, directory_obj *dir, nis_error *status)
{
  fd_result *fd_res;
  XDR xdrs;

  switch (nis_dir_cmp (name, dir->do_name))
    {
    case SAME_NAME:
      *status = NIS_SUCCESS;
      return dir;
    case NOT_SEQUENTIAL:
      /* NOT_SEQUENTIAL means, go one up and try it there ! */
    case HIGHER_NAME:
      { /* We need data from a parent domain */
	directory_obj *obj;
	const char *ndomain = __nis_domain_of (dir->do_name);

	/* The root server of our domain is a replica of the parent
	   domain ! (Now I understand why a root server must be a
	   replica of the parent domain) */
	fd_res = __nis_finddirectory (dir, ndomain);
	if (fd_res == NULL)
	  {
	    nis_free_directory (dir);
	    *status = NIS_NOMEMORY;
	    return NULL;
	  }
	*status = fd_res->status;
	if (fd_res->status != NIS_SUCCESS)
	  {
	    /* Try the current directory obj, maybe it works */
	    __free_fdresult (fd_res);
	    return dir;
	  }
	nis_free_directory (dir);
	obj = calloc (1, sizeof (directory_obj));
	if (obj == NULL)
	  {
	    __free_fdresult (fd_res);
	    *status = NIS_NOMEMORY;
	    return NULL;
	  }
	xdrmem_create (&xdrs, fd_res->dir_data.dir_data_val,
		       fd_res->dir_data.dir_data_len, XDR_DECODE);
	_xdr_directory_obj (&xdrs, obj);
	xdr_destroy (&xdrs);
	__free_fdresult (fd_res);

	/* We have found a NIS+ server serving ndomain, now
	   let us search for "name" */
	return rec_dirsearch (name, obj, status);
      }
      break;
    case LOWER_NAME:
      {
	directory_obj *obj;
	size_t namelen = strlen (name);
	char leaf[namelen + 3];
	char domain[namelen + 3];
	const char *ndomain;
	char *cp;

	strcpy (domain, name);

	do
	  {
	    if (domain[0] == '\0')
	      {
		nis_free_directory (dir);
		return NULL;
	      }
	    nis_leaf_of_r (domain, leaf, sizeof (leaf));
	    ndomain = __nis_domain_of (domain);
	    memmove (domain, ndomain, strlen (ndomain) + 1);
	  }
	while (nis_dir_cmp (domain, dir->do_name) != SAME_NAME);

	cp = rawmemchr (leaf, '\0');
	*cp++ = '.';
	strcpy (cp, domain);

	fd_res = __nis_finddirectory (dir, leaf);
	if (fd_res == NULL)
	  {
	    nis_free_directory (dir);
	    *status = NIS_NOMEMORY;
	    return NULL;
	  }
	*status = fd_res->status;
	if (fd_res->status != NIS_SUCCESS)
	  {
	    /* Try the current directory object, maybe it works */
	    __free_fdresult (fd_res);
	    return dir;
	  }
	nis_free_directory (dir);
	obj = calloc (1, sizeof (directory_obj));
	if (obj == NULL)
	  {
	    __free_fdresult (fd_res);
	    *status = NIS_NOMEMORY;
	    return NULL;
	  }
	xdrmem_create (&xdrs, fd_res->dir_data.dir_data_val,
		       fd_res->dir_data.dir_data_len, XDR_DECODE);
	_xdr_directory_obj (&xdrs, obj);
	xdr_destroy (&xdrs);
	__free_fdresult (fd_res);
	/* We have found a NIS+ server serving ndomain, now
	   let us search for "name" */
	return rec_dirsearch (name, obj, status);
      }
      break;
    case BAD_NAME:
      nis_free_directory (dir);
      *status = NIS_BADNAME;
      return NULL;
    }
  nis_free_directory (dir);
  *status = NIS_FAIL;
  return NULL;
}

/* We try to query the current server for the searched object,
   maybe he know about it ? */
static directory_obj *
first_shoot (const_nis_name name, directory_obj *dir)
{
  directory_obj *obj = NULL;
  fd_result *fd_res;
  XDR xdrs;

  if (nis_dir_cmp (name, dir->do_name) == SAME_NAME)
    return dir;

  fd_res = __nis_finddirectory (dir, name);
  if (fd_res == NULL)
    return NULL;
  if (fd_res->status == NIS_SUCCESS
      && (obj = calloc (1, sizeof (directory_obj))) != NULL)
    {
      xdrmem_create (&xdrs, fd_res->dir_data.dir_data_val,
		     fd_res->dir_data.dir_data_len, XDR_DECODE);
      _xdr_directory_obj (&xdrs, obj);
      xdr_destroy (&xdrs);

      if (strcmp (dir->do_name, obj->do_name) != 0)
	{
	  nis_free_directory (obj);
	  obj = NULL;
	}
    }

  __free_fdresult (fd_res);

  if (obj != NULL)
    nis_free_directory (dir);

  return obj;
}

static struct nis_server_cache
{
  int search_parent;
  int uses;
  unsigned int size;
  unsigned int server_used;
  unsigned int current_ep;
  time_t expires;
  char name[];
} *nis_server_cache[16];
static time_t nis_cold_start_mtime;
__libc_lock_define_initialized (static, nis_server_cache_lock)

static directory_obj *
nis_server_cache_search (const_nis_name name, int search_parent,
			 unsigned int *server_used, unsigned int *current_ep,
			 struct timeval *now)
{
  directory_obj *ret = NULL;
  int i;
  char *addr;
  XDR xdrs;
  struct stat64 st;

  int saved_errno = errno;
  if (stat64 ("/var/nis/NIS_COLD_START", &st) < 0)
    st.st_mtime = nis_cold_start_mtime + 1;
  __set_errno (saved_errno);

  __libc_lock_lock (nis_server_cache_lock);

  for (i = 0; i < 16; ++i)
    if (nis_server_cache[i] == NULL)
      continue;
    else if (st.st_mtime != nis_cold_start_mtime
	     || now->tv_sec > nis_server_cache[i]->expires)
      {
	free (nis_server_cache[i]);
	nis_server_cache[i] = NULL;
      }
    else if (nis_server_cache[i]->search_parent == search_parent
	     && strcmp (nis_server_cache[i]->name, name) == 0)
      {
	ret = calloc (1, sizeof (directory_obj));
	if (ret == NULL)
	  break;

	addr = rawmemchr (nis_server_cache[i]->name, '\0') + 8;
	addr = (char *) ((uintptr_t) addr & ~(uintptr_t) 7);
	xdrmem_create (&xdrs, addr, nis_server_cache[i]->size, XDR_DECODE);
	if (!_xdr_directory_obj (&xdrs, ret))
	  {
	    xdr_destroy (&xdrs);
	    free (ret);
	    ret = NULL;
	    free (nis_server_cache[i]);
	    nis_server_cache[i] = NULL;
	    break;
	  }
	xdr_destroy (&xdrs);
	*server_used = nis_server_cache[i]->server_used;
	*current_ep = nis_server_cache[i]->current_ep;
	break;
      }

  nis_cold_start_mtime = st.st_mtime;

  __libc_lock_unlock (nis_server_cache_lock);
  return ret;
}

static void
nis_server_cache_add (const_nis_name name, int search_parent,
		      directory_obj *dir, unsigned int server_used,
		      unsigned int current_ep, struct timeval *now)
{
  struct nis_server_cache **loc;
  struct nis_server_cache *new;
  struct nis_server_cache *old;
  int i;
  char *addr;
  unsigned int size;
  XDR xdrs;

  if (dir == NULL)
    return;

  size = xdr_sizeof ((xdrproc_t) _xdr_directory_obj, (char *) dir);
  new = calloc (1, sizeof (*new) + strlen (name) + 8 + size);
  if (new == NULL)
    return;
  new->search_parent = search_parent;
  new->uses = 1;
  new->expires = now->tv_sec + dir->do_ttl;
  new->size = size;
  new->server_used = server_used;
  new->current_ep = current_ep;
  addr = stpcpy (new->name, name) + 8;
  addr = (char *) ((uintptr_t) addr & ~(uintptr_t) 7);

  xdrmem_create(&xdrs, addr, size, XDR_ENCODE);
  if (!_xdr_directory_obj (&xdrs, dir))
    {
      xdr_destroy (&xdrs);
      free (new);
      return;
    }
  xdr_destroy (&xdrs);

  __libc_lock_lock (nis_server_cache_lock);

  /* Choose which entry should be evicted from the cache.  */
  loc = &nis_server_cache[0];
  if (*loc != NULL)
    {
      for (i = 1; i < 16; ++i)
	if (nis_server_cache[i] == NULL)
	  {
	    loc = &nis_server_cache[i];
	    break;
	  }
	else if ((*loc)->uses > nis_server_cache[i]->uses
		 || ((*loc)->uses == nis_server_cache[i]->uses
		     && (*loc)->expires > nis_server_cache[i]->expires))
	  loc = &nis_server_cache[i];
    }
  old = *loc;
  *loc = new;

  __libc_lock_unlock (nis_server_cache_lock);
  free (old);
}

nis_error
__nisfind_server (const_nis_name name, int search_parent,
		  directory_obj **dir, dir_binding *dbp, unsigned int flags)
{
  nis_error result = NIS_SUCCESS;
  nis_error status;
  directory_obj *obj;
  struct timeval now;
  unsigned int server_used = ~0;
  unsigned int current_ep = ~0;

  if (name == NULL)
    return NIS_BADNAME;

  if (*dir != NULL)
    return NIS_SUCCESS;

  (void) gettimeofday (&now, NULL);

  if ((flags & NO_CACHE) == 0)
    *dir = nis_server_cache_search (name, search_parent, &server_used,
				    &current_ep, &now);
  if (*dir != NULL)
    {
      unsigned int server_len = (*dir)->do_servers.do_servers_len;
      if (flags & MASTER_ONLY)
	{
	  server_len = 1;
	  if (server_used != 0)
	    {
	      server_used = ~0;
	      current_ep = ~0;
	    }
	}
      result = __nisbind_create (dbp, (*dir)->do_servers.do_servers_val,
				 server_len, server_used, current_ep, flags);
      if (result != NIS_SUCCESS)
	{
	  nis_free_directory (*dir);
	  *dir = NULL;
	}
      return result;
    }

  int saved_errno = errno;
  *dir = readColdStartFile ();
  __set_errno (saved_errno);
  if (*dir == NULL)
    /* No /var/nis/NIS_COLD_START->no NIS+ installed.  */
    return NIS_UNAVAIL;

  /* Try at first, if servers in "dir" know our object */
  const char *search_name = name;
  if (search_parent)
    search_name = __nis_domain_of (name);
  obj = first_shoot (search_name, *dir);
  if (obj == NULL)
    {
      obj = rec_dirsearch (search_name, *dir, &status);
      if (obj == NULL)
	result = status;
    }

  if (result == NIS_SUCCESS)
    {
      unsigned int server_len = obj->do_servers.do_servers_len;
      if (flags & MASTER_ONLY)
	server_len = 1;
      result = __nisbind_create (dbp, obj->do_servers.do_servers_val,
				 server_len, ~0, ~0, flags);
      if (result == NIS_SUCCESS)
	{
	  if ((flags & MASTER_ONLY) == 0
	      || obj->do_servers.do_servers_len == 1)
	    {
	      server_used = dbp->server_used;
	      current_ep = dbp->current_ep;
	    }
	  if ((flags & NO_CACHE) == 0)
	    nis_server_cache_add (name, search_parent, obj,
				  server_used, current_ep, &now);
	}
      else
	{
	  nis_free_directory (obj);
	  obj = NULL;
	}
    }

  *dir = obj;

  return result;
}


nis_error
__prepare_niscall (const_nis_name name, directory_obj **dirp,
		   dir_binding *bptrp, unsigned int flags)
{
  nis_error retcode = __nisfind_server (name, 1, dirp, bptrp, flags);
  if (__glibc_unlikely (retcode != NIS_SUCCESS))
    return retcode;

  do
    if (__nisbind_connect (bptrp) == NIS_SUCCESS)
      return NIS_SUCCESS;
  while (__nisbind_next (bptrp) == NIS_SUCCESS);

  __nisbind_destroy (bptrp);
  memset (bptrp, '\0', sizeof (*bptrp));

  retcode = NIS_NAMEUNREACHABLE;
  nis_free_directory (*dirp);
  *dirp = NULL;

  return retcode;
}
libnsl_hidden_nolink_def (__prepare_niscall, GLIBC_PRIVATE)


nis_error
__do_niscall (const_nis_name name, u_long prog, xdrproc_t xargs,
	      caddr_t req, xdrproc_t xres, caddr_t resp, unsigned int flags,
	      nis_cb *cb)
{
  dir_binding bptr;
  directory_obj *dir = NULL;
  int saved_errno = errno;

  nis_error retcode = __prepare_niscall (name, &dir, &bptr, flags);
  if (retcode == NIS_SUCCESS)
    {
      retcode = __do_niscall3 (&bptr, prog, xargs, req, xres, resp, flags, cb);

      __nisbind_destroy (&bptr);

      nis_free_directory (dir);
    }

  __set_errno (saved_errno);

  return retcode;
}