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
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
|
/* Copyright 2009 Google Inc.
*
* This 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.
*
* This 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 this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
* USA
*/
/* An NSS module which adds supports for file maps with a trailing .cache
* suffix (/etc/passwd.cache, /etc/group.cache, and /etc/shadow.cache)
*/
#include "nss_cache.h"
#include <sys/mman.h>
// Locking implementation: use pthreads.
#include <pthread.h>
static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
#pragma weak pthread_mutex_lock
#define NSS_CACHE_LOCK() do { \
if (&pthread_mutex_lock != NULL) pthread_mutex_lock(&mutex); \
} while (0)
#pragma weak pthread_mutex_unlock
#define NSS_CACHE_UNLOCK() do { \
if (&pthread_mutex_unlock != NULL) pthread_mutex_unlock(&mutex); \
} while (0)
static FILE *p_file = NULL;
static FILE *g_file = NULL;
static char p_filename[NSS_CACHE_PATH_LENGTH] = "/etc/passwd.cache";
static char g_filename[NSS_CACHE_PATH_LENGTH] = "/etc/group.cache";
#ifndef BSD
static FILE *s_file = NULL;
static char s_filename[NSS_CACHE_PATH_LENGTH] = "/etc/shadow.cache";
#else
extern int fgetpwent_r(FILE *, struct passwd *, char *, size_t, struct passwd **);
extern int fgetgrent_r(FILE *, struct group *, char *, size_t, struct group **);
#endif // ifndef BSD
/* Common return code routine for all *ent_r_locked functions.
* We need to return TRYAGAIN if the underlying files guy raises ERANGE,
* so that our caller knows to try again with a bigger buffer.
*/
static inline enum nss_status _nss_cache_ent_bad_return_code(int errnoval) {
enum nss_status ret;
switch (errnoval) {
case ERANGE:
DEBUG("ERANGE: Try again with a bigger buffer\n");
ret = NSS_STATUS_TRYAGAIN;
break;
case ENOENT:
default:
DEBUG("ENOENT or default case: Not found\n");
ret = NSS_STATUS_NOTFOUND;
};
return ret;
}
//
// Binary search routines below here
//
int _nss_cache_bsearch2_compare(const void *key, const void *value) {
struct nss_cache_args *args = (struct nss_cache_args *)key;
const char *value_text = (const char *)value;
// Using strcmp as the generation of the index sorts without
// locale awareness.
return strcmp(args->lookup_key, value_text);
}
enum nss_status _nss_cache_bsearch2(struct nss_cache_args *args, int *errnop) {
enum nss_cache_match (*lookup)(FILE *, struct nss_cache_args *) =
args->lookup_function;
FILE *file = NULL;
FILE *system_file_stream = NULL;
struct stat system_file;
struct stat sorted_file;
enum nss_status ret = 100;
long offset = 0;
void *mapped_data = NULL;
file = fopen(args->sorted_filename, "r");
if (file == NULL) {
DEBUG("error opening %s\n", args->sorted_filename);
return NSS_STATUS_UNAVAIL;
}
// if the sorted file is older than the system file, do not risk stale
// data and abort
// TODO(vasilios): should be a compile or runtime option
if (stat(args->system_filename, &system_file) != 0) {
DEBUG("failed to stat %s\n", args->system_filename);
fclose(file);
return NSS_STATUS_UNAVAIL;
}
if (fstat(fileno(file), &sorted_file) != 0) {
DEBUG("failed to stat %s\n", args->sorted_filename);
fclose(file);
return NSS_STATUS_UNAVAIL;
}
if (difftime(system_file.st_mtime, sorted_file.st_mtime) > 0) {
DEBUG("%s may be stale, aborting lookup\n", args->sorted_filename);
fclose(file);
return NSS_STATUS_UNAVAIL;
}
mapped_data =
mmap(NULL, sorted_file.st_size, PROT_READ, MAP_PRIVATE, fileno(file), 0);
if (mapped_data == MAP_FAILED) {
DEBUG("mmap failed\n");
fclose(file);
return NSS_STATUS_UNAVAIL;
}
const char *data = (const char *)mapped_data;
while (*data != '\n') {
++data;
}
long entry_size = data - (const char *)mapped_data + 1;
long entry_count = sorted_file.st_size / entry_size;
void *entry = bsearch(args, mapped_data, entry_count, entry_size,
&_nss_cache_bsearch2_compare);
if (entry != NULL) {
const char *entry_text = entry;
sscanf(entry_text + strlen(entry_text) + 1, "%ld", &offset);
}
if (munmap(mapped_data, sorted_file.st_size) == -1) {
DEBUG("munmap failed\n");
}
fclose(file);
if (entry == NULL) {
return NSS_STATUS_NOTFOUND;
}
system_file_stream = fopen(args->system_filename, "r");
if (system_file_stream == NULL) {
DEBUG("error opening %s\n", args->system_filename);
return NSS_STATUS_UNAVAIL;
}
if (fseek(system_file_stream, offset, SEEK_SET) != 0) {
DEBUG("fseek fail\n");
return NSS_STATUS_UNAVAIL;
}
switch (lookup(system_file_stream, args)) {
case NSS_CACHE_EXACT:
ret = NSS_STATUS_SUCCESS;
break;
case NSS_CACHE_ERROR:
if (errno == ERANGE) {
// let the caller retry
*errnop = errno;
ret = _nss_cache_ent_bad_return_code(*errnop);
}
break;
default:
ret = NSS_STATUS_UNAVAIL;
break;
}
fclose(system_file_stream);
return ret;
}
//
// Routines for passwd map defined below here
//
// _nss_cache_setpwent_path()
// Helper function for testing
extern char *_nss_cache_setpwent_path(const char *path) {
DEBUG("%s %s\n", "Setting p_filename to", path);
return strncpy(p_filename, path, NSS_CACHE_PATH_LENGTH - 1);
}
// _nss_cache_pwuid_wrap()
// Internal wrapper for binary searches, using uid-specific calls.
static enum nss_cache_match _nss_cache_pwuid_wrap(FILE *file,
struct nss_cache_args *args) {
struct passwd *result = args->lookup_result;
uid_t *uid = args->lookup_value;
if (fgetpwent_r(file, result, args->buffer, args->buflen, &result) == 0) {
if (result->pw_uid == *uid) {
DEBUG("SUCCESS: found user %d:%s\n", result->pw_uid, result->pw_name);
return NSS_CACHE_EXACT;
}
DEBUG("Failed match at uid %d\n", result->pw_uid);
if (result->pw_uid > *uid) {
return NSS_CACHE_HIGH;
} else {
return NSS_CACHE_LOW;
}
}
return NSS_CACHE_ERROR;
}
// _nss_cache_pwnam_wrap()
// Internal wrapper for binary searches, using username-specific calls.
static enum nss_cache_match _nss_cache_pwnam_wrap(FILE *file,
struct nss_cache_args *args) {
struct passwd *result = args->lookup_result;
char *name = args->lookup_value;
int ret;
if (fgetpwent_r(file, result, args->buffer, args->buflen, &result) == 0) {
ret = strcoll(result->pw_name, name);
if (ret == 0) {
DEBUG("SUCCESS: found user %s\n", result->pw_name);
return NSS_CACHE_EXACT;
}
DEBUG("Failed match at name %s\n", result->pw_name);
if (ret > 0) {
return NSS_CACHE_HIGH;
} else {
return NSS_CACHE_LOW;
}
}
return NSS_CACHE_ERROR;
}
// _nss_cache_setpwent_locked()
// Internal setup routine
static enum nss_status _nss_cache_setpwent_locked(void) {
DEBUG("%s %s\n", "Opening", p_filename);
p_file = fopen(p_filename, "r");
if (p_file) {
return NSS_STATUS_SUCCESS;
} else {
return NSS_STATUS_UNAVAIL;
}
}
// _nss_cache_setpwent()
// Called by NSS to open the passwd file
// 'stayopen' parameter is ignored.
enum nss_status _nss_cache_setpwent(int stayopen) {
enum nss_status ret;
NSS_CACHE_LOCK();
ret = _nss_cache_setpwent_locked();
NSS_CACHE_UNLOCK();
return ret;
}
// _nss_cache_endpwent_locked()
// Internal close routine
static enum nss_status _nss_cache_endpwent_locked(void) {
DEBUG("Closing passwd.cache\n");
if (p_file) {
fclose(p_file);
p_file = NULL;
}
return NSS_STATUS_SUCCESS;
}
// _nss_cache_endpwent()
// Called by NSS to close the passwd file
enum nss_status _nss_cache_endpwent(void) {
enum nss_status ret;
NSS_CACHE_LOCK();
ret = _nss_cache_endpwent_locked();
NSS_CACHE_UNLOCK();
return ret;
}
// _nss_cache_getpwent_r_locked()
// Called internally to return the next entry from the passwd file
static enum nss_status _nss_cache_getpwent_r_locked(struct passwd *result,
char *buffer, size_t buflen,
int *errnop) {
enum nss_status ret = NSS_STATUS_SUCCESS;
if (p_file == NULL) {
DEBUG("p_file == NULL, going to setpwent\n");
ret = _nss_cache_setpwent_locked();
}
if (ret == NSS_STATUS_SUCCESS) {
if (fgetpwent_r(p_file, result, buffer, buflen, &result) == 0) {
DEBUG("Returning user %d:%s\n", result->pw_uid, result->pw_name);
} else {
if (errno == ENOENT) {
errno = 0;
}
*errnop = errno;
ret = _nss_cache_ent_bad_return_code(*errnop);
}
}
return ret;
}
// _nss_cache_getpwent_r()
// Called by NSS to look up next entry in passwd file
enum nss_status _nss_cache_getpwent_r(struct passwd *result, char *buffer,
size_t buflen, int *errnop) {
enum nss_status ret;
NSS_CACHE_LOCK();
ret = _nss_cache_getpwent_r_locked(result, buffer, buflen, errnop);
NSS_CACHE_UNLOCK();
return ret;
}
// _nss_cache_getpwuid_r()
// Find a user account by uid
enum nss_status _nss_cache_getpwuid_r(uid_t uid, struct passwd *result,
char *buffer, size_t buflen,
int *errnop) {
char filename[NSS_CACHE_PATH_LENGTH];
struct nss_cache_args args;
enum nss_status ret;
strncpy(filename, p_filename, NSS_CACHE_PATH_LENGTH - 1);
if (strlen(filename) > NSS_CACHE_PATH_LENGTH - 7) {
DEBUG("filename too long\n");
return NSS_STATUS_UNAVAIL;
}
strncat(filename, ".ixuid", 6);
args.sorted_filename = filename;
args.system_filename = p_filename;
args.lookup_function = _nss_cache_pwuid_wrap;
args.lookup_value = &uid;
args.lookup_result = result;
args.buffer = buffer;
args.buflen = buflen;
char uid_text[11];
snprintf(uid_text, sizeof(uid_text), "%d", uid);
args.lookup_key = uid_text;
args.lookup_key_length = strlen(uid_text);
DEBUG("Binary search for uid %d\n", uid);
NSS_CACHE_LOCK();
ret = _nss_cache_bsearch2(&args, errnop);
if (ret == NSS_STATUS_UNAVAIL) {
DEBUG("Binary search failed, falling back to full linear search\n");
ret = _nss_cache_setpwent_locked();
if (ret == NSS_STATUS_SUCCESS) {
while ((ret = _nss_cache_getpwent_r_locked(
result, buffer, buflen, errnop)) == NSS_STATUS_SUCCESS) {
if (result->pw_uid == uid)
break;
}
}
}
_nss_cache_endpwent_locked();
NSS_CACHE_UNLOCK();
return ret;
}
// _nss_cache_getpwnam_r()
// Find a user account by name
enum nss_status _nss_cache_getpwnam_r(const char *name, struct passwd *result,
char *buffer, size_t buflen,
int *errnop) {
char *pw_name;
char filename[NSS_CACHE_PATH_LENGTH];
struct nss_cache_args args;
enum nss_status ret;
NSS_CACHE_LOCK();
// name is a const char, we need a non-const copy
pw_name = malloc(strlen(name) + 1);
if (pw_name == NULL) {
DEBUG("malloc error\n");
return NSS_STATUS_UNAVAIL;
}
strncpy(pw_name, name, strlen(name) + 1);
strncpy(filename, p_filename, NSS_CACHE_PATH_LENGTH - 1);
if (strlen(filename) > NSS_CACHE_PATH_LENGTH - 8) {
DEBUG("filename too long\n");
free(pw_name);
return NSS_STATUS_UNAVAIL;
}
strncat(filename, ".ixname", 7);
args.sorted_filename = filename;
args.system_filename = p_filename;
args.lookup_function = _nss_cache_pwnam_wrap;
args.lookup_value = pw_name;
args.lookup_result = result;
args.buffer = buffer;
args.buflen = buflen;
args.lookup_key = pw_name;
args.lookup_key_length = strlen(pw_name);
DEBUG("Binary search for user %s\n", pw_name);
ret = _nss_cache_bsearch2(&args, errnop);
if (ret == NSS_STATUS_UNAVAIL) {
DEBUG("Binary search failed, falling back to full linear search\n");
ret = _nss_cache_setpwent_locked();
if (ret == NSS_STATUS_SUCCESS) {
while ((ret = _nss_cache_getpwent_r_locked(
result, buffer, buflen, errnop)) == NSS_STATUS_SUCCESS) {
if (!strcmp(result->pw_name, name))
break;
}
}
}
free(pw_name);
_nss_cache_endpwent_locked();
NSS_CACHE_UNLOCK();
return ret;
}
//
// Routines for group map defined here.
//
// _nss_cache_setgrent_path()
// Helper function for testing
extern char *_nss_cache_setgrent_path(const char *path) {
DEBUG("%s %s\n", "Setting g_filename to", path);
return strncpy(g_filename, path, NSS_CACHE_PATH_LENGTH - 1);
}
// _nss_cache_setgrent_locked()
// Internal setup routine
static enum nss_status _nss_cache_setgrent_locked(void) {
DEBUG("%s %s\n", "Opening", g_filename);
g_file = fopen(g_filename, "r");
if (g_file) {
return NSS_STATUS_SUCCESS;
} else {
return NSS_STATUS_UNAVAIL;
}
}
// _nss_cache_grgid_wrap()
// Internal wrapper for binary searches, using gid-specific calls.
static enum nss_cache_match _nss_cache_grgid_wrap(FILE *file,
struct nss_cache_args *args) {
struct group *result = args->lookup_result;
gid_t *gid = args->lookup_value;
if (fgetgrent_r(file, result, args->buffer, args->buflen, &result) == 0) {
if (result->gr_gid == *gid) {
DEBUG("SUCCESS: found group %d:%s\n", result->gr_gid, result->gr_name);
return NSS_CACHE_EXACT;
}
DEBUG("Failed match at gid %d\n", result->gr_gid);
if (result->gr_gid > *gid) {
return NSS_CACHE_HIGH;
} else {
return NSS_CACHE_LOW;
}
}
return NSS_CACHE_ERROR;
}
// _nss_cache_grnam_wrap()
// Internal wrapper for binary searches, using groupname-specific calls.
static enum nss_cache_match _nss_cache_grnam_wrap(FILE *file,
struct nss_cache_args *args) {
struct group *result = args->lookup_result;
char *name = args->lookup_value;
int ret;
if (fgetgrent_r(file, result, args->buffer, args->buflen, &result) == 0) {
ret = strcoll(result->gr_name, name);
if (ret == 0) {
DEBUG("SUCCESS: found group %s\n", result->gr_name);
return NSS_CACHE_EXACT;
}
DEBUG("Failed match at name %s\n", result->gr_name);
if (ret > 0) {
return NSS_CACHE_HIGH;
} else {
return NSS_CACHE_LOW;
}
}
return NSS_CACHE_ERROR;
}
// _nss_cache_setgrent()
// Called by NSS to open the group file
// 'stayopen' parameter is ignored.
enum nss_status _nss_cache_setgrent(int stayopen) {
enum nss_status ret;
NSS_CACHE_LOCK();
ret = _nss_cache_setgrent_locked();
NSS_CACHE_UNLOCK();
return ret;
}
// _nss_cache_endgrent_locked()
// Internal close routine
static enum nss_status _nss_cache_endgrent_locked(void) {
DEBUG("Closing group.cache\n");
if (g_file) {
fclose(g_file);
g_file = NULL;
}
return NSS_STATUS_SUCCESS;
}
// _nss_cache_endgrent()
// Called by NSS to close the group file
enum nss_status _nss_cache_endgrent(void) {
enum nss_status ret;
NSS_CACHE_LOCK();
ret = _nss_cache_endgrent_locked();
NSS_CACHE_UNLOCK();
return ret;
}
// _nss_cache_getgrent_r_locked()
// Called internally to return the next entry from the group file
static enum nss_status _nss_cache_getgrent_r_locked(struct group *result,
char *buffer, size_t buflen,
int *errnop) {
enum nss_status ret = NSS_STATUS_SUCCESS;
if (g_file == NULL) {
DEBUG("g_file == NULL, going to setgrent\n");
ret = _nss_cache_setgrent_locked();
}
if (ret == NSS_STATUS_SUCCESS) {
fpos_t position;
fgetpos(g_file, &position);
if (fgetgrent_r(g_file, result, buffer, buflen, &result) == 0) {
DEBUG("Returning group %s (%d)\n", result->gr_name, result->gr_gid);
} else {
/* Rewind back to where we were just before, otherwise the data read
* into the buffer is probably going to be lost because there's no
* guarantee that the caller is going to have preserved the line we
* just read. Note that glibc's nss/nss_files/files-XXX.c does
* something similar in CONCAT(_nss_files_get,ENTNAME_r) (around
* line 242 in glibc 2.4 sources).
*/
if (errno == ENOENT) {
errno = 0;
} else {
fsetpos(g_file, &position);
}
*errnop = errno;
ret = _nss_cache_ent_bad_return_code(*errnop);
}
}
return ret;
}
// _nss_cache_getgrent_r()
// Called by NSS to look up next entry in group file
enum nss_status _nss_cache_getgrent_r(struct group *result, char *buffer,
size_t buflen, int *errnop) {
enum nss_status ret;
NSS_CACHE_LOCK();
ret = _nss_cache_getgrent_r_locked(result, buffer, buflen, errnop);
NSS_CACHE_UNLOCK();
return ret;
}
// _nss_cache_getgrgid_r()
// Find a group by gid
enum nss_status _nss_cache_getgrgid_r(gid_t gid, struct group *result,
char *buffer, size_t buflen,
int *errnop) {
char filename[NSS_CACHE_PATH_LENGTH];
struct nss_cache_args args;
enum nss_status ret;
// Since we binary search over the groups using the user provided
// buffer, we do not start searching before we have a buffer that
// is big enough to have a high chance of succeeding.
if (buflen < (1 << 20)) {
*errnop = ERANGE;
return NSS_STATUS_TRYAGAIN;
}
strncpy(filename, g_filename, NSS_CACHE_PATH_LENGTH - 1);
if (strlen(filename) > NSS_CACHE_PATH_LENGTH - 7) {
DEBUG("filename too long\n");
return NSS_STATUS_UNAVAIL;
}
strncat(filename, ".ixgid", 6);
args.sorted_filename = filename;
args.system_filename = g_filename;
args.lookup_function = _nss_cache_grgid_wrap;
args.lookup_value = &gid;
args.lookup_result = result;
args.buffer = buffer;
args.buflen = buflen;
char gid_text[11];
snprintf(gid_text, sizeof(gid_text), "%d", gid);
args.lookup_key = gid_text;
args.lookup_key_length = strlen(gid_text);
DEBUG("Binary search for gid %d\n", gid);
NSS_CACHE_LOCK();
ret = _nss_cache_bsearch2(&args, errnop);
if (ret == NSS_STATUS_UNAVAIL) {
DEBUG("Binary search failed, falling back to full linear search\n");
ret = _nss_cache_setgrent_locked();
if (ret == NSS_STATUS_SUCCESS) {
while ((ret = _nss_cache_getgrent_r_locked(
result, buffer, buflen, errnop)) == NSS_STATUS_SUCCESS) {
if (result->gr_gid == gid)
break;
}
}
}
_nss_cache_endgrent_locked();
NSS_CACHE_UNLOCK();
return ret;
}
// _nss_cache_getgrnam_r()
// Find a group by name
enum nss_status _nss_cache_getgrnam_r(const char *name, struct group *result,
char *buffer, size_t buflen,
int *errnop) {
char *gr_name;
char filename[NSS_CACHE_PATH_LENGTH];
struct nss_cache_args args;
enum nss_status ret;
NSS_CACHE_LOCK();
// name is a const char, we need a non-const copy
gr_name = malloc(strlen(name) + 1);
if (gr_name == NULL) {
DEBUG("malloc error\n");
return NSS_STATUS_UNAVAIL;
}
strncpy(gr_name, name, strlen(name) + 1);
strncpy(filename, g_filename, NSS_CACHE_PATH_LENGTH - 1);
if (strlen(filename) > NSS_CACHE_PATH_LENGTH - 8) {
DEBUG("filename too long\n");
free(gr_name);
return NSS_STATUS_UNAVAIL;
}
strncat(filename, ".ixname", 7);
args.sorted_filename = filename;
args.system_filename = g_filename;
args.lookup_function = _nss_cache_grnam_wrap;
args.lookup_value = gr_name;
args.lookup_result = result;
args.buffer = buffer;
args.buflen = buflen;
args.lookup_key = gr_name;
args.lookup_key_length = strlen(gr_name);
DEBUG("Binary search for group %s\n", gr_name);
ret = _nss_cache_bsearch2(&args, errnop);
if (ret == NSS_STATUS_UNAVAIL) {
DEBUG("Binary search failed, falling back to full linear search\n");
ret = _nss_cache_setgrent_locked();
if (ret == NSS_STATUS_SUCCESS) {
while ((ret = _nss_cache_getgrent_r_locked(
result, buffer, buflen, errnop)) == NSS_STATUS_SUCCESS) {
if (!strcmp(result->gr_name, name))
break;
}
}
}
free(gr_name);
_nss_cache_endgrent_locked();
NSS_CACHE_UNLOCK();
return ret;
}
//
// Routines for shadow map defined here.
//
#ifndef BSD
// _nss_cache_setspent_path()
// Helper function for testing
extern char *_nss_cache_setspent_path(const char *path) {
DEBUG("%s %s\n", "Setting s_filename to", path);
return strncpy(s_filename, path, NSS_CACHE_PATH_LENGTH - 1);
}
// _nss_cache_setspent_locked()
// Internal setup routine
static enum nss_status _nss_cache_setspent_locked(void) {
DEBUG("%s %s\n", "Opening", g_filename);
s_file = fopen(s_filename, "r");
if (s_file) {
return NSS_STATUS_SUCCESS;
} else {
return NSS_STATUS_UNAVAIL;
}
}
// _nss_cache_spnam_wrap()
// Internal wrapper for binary searches, using shadow-specific calls.
static enum nss_cache_match _nss_cache_spnam_wrap(FILE *file,
struct nss_cache_args *args) {
struct spwd *result = args->lookup_result;
char *name = args->lookup_value;
int ret;
if (fgetspent_r(file, result, args->buffer, args->buflen, &result) == 0) {
ret = strcoll(result->sp_namp, name);
if (ret == 0) {
DEBUG("SUCCESS: found user %s\n", result->sp_namp);
return NSS_CACHE_EXACT;
}
DEBUG("Failed match at name %s\n", result->sp_namp);
if (ret > 0) {
return NSS_CACHE_HIGH;
} else {
return NSS_CACHE_LOW;
}
}
return NSS_CACHE_ERROR;
}
// _nss_cache_setspent()
// Called by NSS to open the shadow file
// 'stayopen' parameter is ignored.
enum nss_status _nss_cache_setspent(int stayopen) {
enum nss_status ret;
NSS_CACHE_LOCK();
ret = _nss_cache_setspent_locked();
NSS_CACHE_UNLOCK();
return ret;
}
// _nss_cache_endspent_locked()
// Internal close routine
static enum nss_status _nss_cache_endspent_locked(void) {
DEBUG("Closing shadow.cache\n");
if (s_file) {
fclose(s_file);
s_file = NULL;
}
return NSS_STATUS_SUCCESS;
}
// _nss_cache_endspent()
// Called by NSS to close the shadow file
enum nss_status _nss_cache_endspent(void) {
enum nss_status ret;
NSS_CACHE_LOCK();
ret = _nss_cache_endspent_locked();
NSS_CACHE_UNLOCK();
return ret;
}
// _nss_cache_getspent_r_locked()
// Called internally to return the next entry from the shadow file
static enum nss_status _nss_cache_getspent_r_locked(struct spwd *result,
char *buffer, size_t buflen,
int *errnop) {
enum nss_status ret = NSS_STATUS_SUCCESS;
if (s_file == NULL) {
DEBUG("s_file == NULL, going to setspent\n");
ret = _nss_cache_setspent_locked();
}
if (ret == NSS_STATUS_SUCCESS) {
if (fgetspent_r(s_file, result, buffer, buflen, &result) == 0) {
DEBUG("Returning shadow entry %s\n", result->sp_namp);
} else {
if (errno == ENOENT) {
errno = 0;
}
*errnop = errno;
ret = _nss_cache_ent_bad_return_code(*errnop);
}
}
return ret;
}
// _nss_cache_getspent_r()
// Called by NSS to look up next entry in the shadow file
enum nss_status _nss_cache_getspent_r(struct spwd *result, char *buffer,
size_t buflen, int *errnop) {
enum nss_status ret;
NSS_CACHE_LOCK();
ret = _nss_cache_getspent_r_locked(result, buffer, buflen, errnop);
NSS_CACHE_UNLOCK();
return ret;
}
// _nss_cache_getspnam_r()
// Find a user by name
enum nss_status _nss_cache_getspnam_r(const char *name, struct spwd *result,
char *buffer, size_t buflen,
int *errnop) {
char *sp_namp;
char filename[NSS_CACHE_PATH_LENGTH];
struct nss_cache_args args;
enum nss_status ret;
NSS_CACHE_LOCK();
// name is a const char, we need a non-const copy
sp_namp = malloc(strlen(name) + 1);
if (sp_namp == NULL) {
DEBUG("malloc error\n");
return NSS_STATUS_UNAVAIL;
}
strncpy(sp_namp, name, strlen(name) + 1);
strncpy(filename, s_filename, NSS_CACHE_PATH_LENGTH - 1);
if (strlen(filename) > NSS_CACHE_PATH_LENGTH - 8) {
DEBUG("filename too long\n");
free(sp_namp);
return NSS_STATUS_UNAVAIL;
}
strncat(filename, ".ixname", 7);
args.sorted_filename = filename;
args.system_filename = s_filename;
args.lookup_function = _nss_cache_spnam_wrap;
args.lookup_value = sp_namp;
args.lookup_result = result;
args.buffer = buffer;
args.buflen = buflen;
args.lookup_key = sp_namp;
args.lookup_key_length = strlen(sp_namp);
DEBUG("Binary search for user %s\n", sp_namp);
ret = _nss_cache_bsearch2(&args, errnop);
if (ret == NSS_STATUS_UNAVAIL) {
DEBUG("Binary search failed, falling back to full linear search\n");
ret = _nss_cache_setspent_locked();
if (ret == NSS_STATUS_SUCCESS) {
while ((ret = _nss_cache_getspent_r_locked(
result, buffer, buflen, errnop)) == NSS_STATUS_SUCCESS) {
if (!strcmp(result->sp_namp, name))
break;
}
}
}
free(sp_namp);
_nss_cache_endspent_locked();
NSS_CACHE_UNLOCK();
return ret;
}
#else
#include "bsdnss.c"
#endif // ifndef BSD
|