1 /* $NetBSD: nsdispatch.c,v 1.9 1999/01/25 00:16:17 lukem Exp $ */
2
3 /*-
4 * SPDX-License-Identifier: BSD-2-Clause-NetBSD
5 *
6 * Copyright (c) 1997, 1998, 1999 The NetBSD Foundation, Inc.
7 * All rights reserved.
8 *
9 * This code is derived from software contributed to The NetBSD Foundation
10 * by Luke Mewburn.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
22 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
23 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
24 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
25 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
26 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
27 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
29 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
30 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
31 * POSSIBILITY OF SUCH DAMAGE.
32 */
33 /*-
34 * Copyright (c) 2003 Networks Associates Technology, Inc.
35 * All rights reserved.
36 *
37 * Portions of this software were developed for the FreeBSD Project by
38 * Jacques A. Vidrine, Safeport Network Services, and Network
39 * Associates Laboratories, the Security Research Division of Network
40 * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035
41 * ("CBOSS"), as part of the DARPA CHATS research program.
42 *
43 * Redistribution and use in source and binary forms, with or without
44 * modification, are permitted provided that the following conditions
45 * are met:
46 * 1. Redistributions of source code must retain the above copyright
47 * notice, this list of conditions and the following disclaimer.
48 * 2. Redistributions in binary form must reproduce the above copyright
49 * notice, this list of conditions and the following disclaimer in the
50 * documentation and/or other materials provided with the distribution.
51 *
52 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
53 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
54 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
55 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
56 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
57 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
58 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
59 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
60 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
61 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
62 * SUCH DAMAGE.
63 *
64 */
65 #include <sys/cdefs.h>
66 __FBSDID("$FreeBSD$");
67
68 #include "namespace.h"
69 #include <sys/param.h>
70 #include <sys/stat.h>
71
72 #include <dlfcn.h>
73 #include <errno.h>
74 #include <fcntl.h>
75 #define _NS_PRIVATE
76 #include <nsswitch.h>
77 #include <pthread.h>
78 #include <pthread_np.h>
79 #include <stdio.h>
80 #include <stdlib.h>
81 #include <string.h>
82 #include <syslog.h>
83 #include <unistd.h>
84 #include "un-namespace.h"
85 #include "nss_tls.h"
86 #include "libc_private.h"
87 #ifdef NS_CACHING
88 #include "nscache.h"
89 #endif
90
91 enum _nss_constants {
92 /* Number of elements allocated when we grow a vector */
93 ELEMSPERCHUNK = 8
94 };
95
96 /*
97 * Global NSS data structures are mostly read-only, but we update
98 * them when we read or re-read the nsswitch.conf.
99 */
100 static pthread_rwlock_t nss_lock = PTHREAD_RWLOCK_INITIALIZER;
101
102 /*
103 * Runtime determination of whether we are dynamically linked or not.
104 */
105 extern int _DYNAMIC __attribute__ ((weak));
106 #define is_dynamic() (&_DYNAMIC != NULL)
107
108 /*
109 * default sourcelist: `files'
110 */
111 const ns_src __nsdefaultsrc[] = {
112 { NSSRC_FILES, NS_SUCCESS },
113 { 0 },
114 };
115
116 /* Database, source mappings. */
117 static unsigned int _nsmapsize;
118 static ns_dbt *_nsmap = NULL;
119
120 /* NSS modules. */
121 static unsigned int _nsmodsize;
122 static ns_mod *_nsmod;
123
124 /* Placeholder for builtin modules' dlopen `handle'. */
125 static int __nss_builtin_handle;
126 static void *nss_builtin_handle = &__nss_builtin_handle;
127
128 #ifdef NS_CACHING
129 /*
130 * Cache lookup cycle prevention function - if !NULL then no cache lookups
131 * will be made
132 */
133 static void *nss_cache_cycle_prevention_func = NULL;
134 #endif
135
136 /*
137 * We keep track of nsdispatch() nesting depth in dispatch_depth. When a
138 * fallback method is invoked from nsdispatch(), we temporarily set
139 * fallback_depth to the current dispatch depth plus one. Subsequent
140 * calls at that exact depth will run in fallback mode (restricted to the
141 * same source as the call that was handled by the fallback method), while
142 * calls below that depth will be handled normally, allowing fallback
143 * methods to perform arbitrary lookups.
144 */
145 struct fb_state {
146 int dispatch_depth;
147 int fallback_depth;
148 };
149 static void fb_endstate(void *);
150 NSS_TLS_HANDLING(fb);
151
152 /*
153 * Attempt to spew relatively uniform messages to syslog.
154 */
155 #define nss_log(level, fmt, ...) \
156 syslog((level), "NSSWITCH(%s): " fmt, __func__, __VA_ARGS__)
157 #define nss_log_simple(level, s) \
158 syslog((level), "NSSWITCH(%s): " s, __func__)
159
160 /*
161 * Dynamically growable arrays are used for lists of databases, sources,
162 * and modules. The following `vector' interface is used to isolate the
163 * common operations.
164 */
165 typedef int (*vector_comparison)(const void *, const void *);
166 typedef void (*vector_free_elem)(void *);
167 static void vector_sort(void *, unsigned int, size_t,
168 vector_comparison);
169 static void vector_free(void *, unsigned int *, size_t,
170 vector_free_elem);
171 static void *vector_ref(unsigned int, void *, unsigned int, size_t);
172 static void *vector_search(const void *, void *, unsigned int, size_t,
173 vector_comparison);
174 static void *vector_append(const void *, void *, unsigned int *, size_t);
175
176
177 /*
178 * Internal interfaces.
179 */
180 static int string_compare(const void *, const void *);
181 static int mtab_compare(const void *, const void *);
182 static int nss_configure(void);
183 static void ns_dbt_free(ns_dbt *);
184 static void ns_mod_free(ns_mod *);
185 static void ns_src_free(ns_src **, int);
186 static void nss_load_builtin_modules(void);
187 static void nss_load_module(const char *, nss_module_register_fn);
188 static void nss_atexit(void);
189 /* nsparser */
190 extern FILE *_nsyyin;
191
192
193 /*
194 * The vector operations
195 */
196 static void
vector_sort(void * vec,unsigned int count,size_t esize,vector_comparison comparison)197 vector_sort(void *vec, unsigned int count, size_t esize,
198 vector_comparison comparison)
199 {
200 qsort(vec, count, esize, comparison);
201 }
202
203
204 static void *
vector_search(const void * key,void * vec,unsigned int count,size_t esize,vector_comparison comparison)205 vector_search(const void *key, void *vec, unsigned int count, size_t esize,
206 vector_comparison comparison)
207 {
208 return (bsearch(key, vec, count, esize, comparison));
209 }
210
211
212 static void *
vector_append(const void * elem,void * vec,unsigned int * count,size_t esize)213 vector_append(const void *elem, void *vec, unsigned int *count, size_t esize)
214 {
215 void *p;
216
217 if ((*count % ELEMSPERCHUNK) == 0) {
218 p = reallocarray(vec, *count + ELEMSPERCHUNK, esize);
219 if (p == NULL) {
220 nss_log_simple(LOG_ERR, "memory allocation failure");
221 return (vec);
222 }
223 vec = p;
224 }
225 memmove((void *)(((uintptr_t)vec) + (*count * esize)), elem, esize);
226 (*count)++;
227 return (vec);
228 }
229
230
231 static void *
vector_ref(unsigned int i,void * vec,unsigned int count,size_t esize)232 vector_ref(unsigned int i, void *vec, unsigned int count, size_t esize)
233 {
234 if (i < count)
235 return (void *)((uintptr_t)vec + (i * esize));
236 else
237 return (NULL);
238 }
239
240
241 #define VECTOR_FREE(v, c, s, f) \
242 do { vector_free(v, c, s, f); v = NULL; } while (0)
243 static void
vector_free(void * vec,unsigned int * count,size_t esize,vector_free_elem free_elem)244 vector_free(void *vec, unsigned int *count, size_t esize,
245 vector_free_elem free_elem)
246 {
247 unsigned int i;
248 void *elem;
249
250 for (i = 0; i < *count; i++) {
251 elem = vector_ref(i, vec, *count, esize);
252 if (elem != NULL)
253 free_elem(elem);
254 }
255 free(vec);
256 *count = 0;
257 }
258
259 /*
260 * Comparison functions for vector_search.
261 */
262 static int
string_compare(const void * a,const void * b)263 string_compare(const void *a, const void *b)
264 {
265 return (strcasecmp(*(const char * const *)a, *(const char * const *)b));
266 }
267
268
269 static int
mtab_compare(const void * a,const void * b)270 mtab_compare(const void *a, const void *b)
271 {
272 int cmp;
273
274 cmp = strcmp(((const ns_mtab *)a)->name, ((const ns_mtab *)b)->name);
275 if (cmp != 0)
276 return (cmp);
277 else
278 return (strcmp(((const ns_mtab *)a)->database,
279 ((const ns_mtab *)b)->database));
280 }
281
282 /*
283 * NSS nsmap management.
284 */
285 void
_nsdbtaddsrc(ns_dbt * dbt,const ns_src * src)286 _nsdbtaddsrc(ns_dbt *dbt, const ns_src *src)
287 {
288 const ns_mod *modp;
289
290 dbt->srclist = vector_append(src, dbt->srclist, &dbt->srclistsize,
291 sizeof(*src));
292 modp = vector_search(&src->name, _nsmod, _nsmodsize, sizeof(*_nsmod),
293 string_compare);
294 if (modp == NULL)
295 nss_load_module(src->name, NULL);
296 }
297
298
299 #ifdef _NSS_DEBUG
300 void
_nsdbtdump(const ns_dbt * dbt)301 _nsdbtdump(const ns_dbt *dbt)
302 {
303 int i;
304
305 printf("%s (%d source%s):", dbt->name, dbt->srclistsize,
306 dbt->srclistsize == 1 ? "" : "s");
307 for (i = 0; i < (int)dbt->srclistsize; i++) {
308 printf(" %s", dbt->srclist[i].name);
309 if (!(dbt->srclist[i].flags &
310 (NS_UNAVAIL|NS_NOTFOUND|NS_TRYAGAIN)) &&
311 (dbt->srclist[i].flags & NS_SUCCESS))
312 continue;
313 printf(" [");
314 if (!(dbt->srclist[i].flags & NS_SUCCESS))
315 printf(" SUCCESS=continue");
316 if (dbt->srclist[i].flags & NS_UNAVAIL)
317 printf(" UNAVAIL=return");
318 if (dbt->srclist[i].flags & NS_NOTFOUND)
319 printf(" NOTFOUND=return");
320 if (dbt->srclist[i].flags & NS_TRYAGAIN)
321 printf(" TRYAGAIN=return");
322 printf(" ]");
323 }
324 printf("\n");
325 }
326 #endif
327
328
329 /*
330 * The first time nsdispatch is called (during a process's lifetime,
331 * or after nsswitch.conf has been updated), nss_configure will
332 * prepare global data needed by NSS.
333 */
334 static int
nss_configure(void)335 nss_configure(void)
336 {
337 static time_t confmod;
338 struct stat statbuf;
339 int result, isthreaded;
340 const char *path;
341 #ifdef NS_CACHING
342 void *handle;
343 #endif
344
345 result = 0;
346 isthreaded = __isthreaded;
347 #if defined(_NSS_DEBUG) && defined(_NSS_SHOOT_FOOT)
348 /* NOTE WELL: THIS IS A SECURITY HOLE. This must only be built
349 * for debugging purposes and MUST NEVER be used in production.
350 */
351 path = getenv("NSSWITCH_CONF");
352 if (path == NULL)
353 #endif
354 path = _PATH_NS_CONF;
355 if (stat(path, &statbuf) != 0)
356 return (0);
357 if (statbuf.st_mtime <= confmod)
358 return (0);
359 if (isthreaded) {
360 (void)_pthread_rwlock_unlock(&nss_lock);
361 result = _pthread_rwlock_wrlock(&nss_lock);
362 if (result != 0)
363 return (result);
364 if (stat(path, &statbuf) != 0)
365 goto fin;
366 if (statbuf.st_mtime <= confmod)
367 goto fin;
368 }
369 _nsyyin = fopen(path, "re");
370 if (_nsyyin == NULL)
371 goto fin;
372 VECTOR_FREE(_nsmap, &_nsmapsize, sizeof(*_nsmap),
373 (vector_free_elem)ns_dbt_free);
374 VECTOR_FREE(_nsmod, &_nsmodsize, sizeof(*_nsmod),
375 (vector_free_elem)ns_mod_free);
376 if (confmod == 0)
377 (void)atexit(nss_atexit);
378 nss_load_builtin_modules();
379 _nsyyparse();
380 (void)fclose(_nsyyin);
381 vector_sort(_nsmap, _nsmapsize, sizeof(*_nsmap), string_compare);
382 confmod = statbuf.st_mtime;
383
384 #ifdef NS_CACHING
385 handle = libc_dlopen(NULL, RTLD_LAZY | RTLD_GLOBAL);
386 if (handle != NULL) {
387 nss_cache_cycle_prevention_func = dlsym(handle,
388 "_nss_cache_cycle_prevention_function");
389 dlclose(handle);
390 }
391 #endif
392 fin:
393 if (isthreaded) {
394 (void)_pthread_rwlock_unlock(&nss_lock);
395 if (result == 0)
396 result = _pthread_rwlock_rdlock(&nss_lock);
397 }
398 return (result);
399 }
400
401
402 void
_nsdbtput(const ns_dbt * dbt)403 _nsdbtput(const ns_dbt *dbt)
404 {
405 unsigned int i;
406 ns_dbt *p;
407
408 for (i = 0; i < _nsmapsize; i++) {
409 p = vector_ref(i, _nsmap, _nsmapsize, sizeof(*_nsmap));
410 if (string_compare(&dbt->name, &p->name) == 0) {
411 /* overwrite existing entry */
412 if (p->srclist != NULL)
413 ns_src_free(&p->srclist, p->srclistsize);
414 memmove(p, dbt, sizeof(*dbt));
415 return;
416 }
417 }
418 _nsmap = vector_append(dbt, _nsmap, &_nsmapsize, sizeof(*_nsmap));
419 }
420
421
422 static void
ns_dbt_free(ns_dbt * dbt)423 ns_dbt_free(ns_dbt *dbt)
424 {
425 ns_src_free(&dbt->srclist, dbt->srclistsize);
426 if (dbt->name)
427 free((void *)dbt->name);
428 }
429
430
431 static void
ns_src_free(ns_src ** src,int srclistsize)432 ns_src_free(ns_src **src, int srclistsize)
433 {
434 int i;
435
436 for (i = 0; i < srclistsize; i++)
437 if ((*src)[i].name != NULL)
438 /* This one was allocated by nslexer. You'll just
439 * have to trust me.
440 */
441 free((void *)((*src)[i].name));
442 free(*src);
443 *src = NULL;
444 }
445
446
447
448 /*
449 * NSS module management.
450 */
451 /* The built-in NSS modules are all loaded at once. */
452 #define NSS_BACKEND(name, reg) \
453 ns_mtab *reg(unsigned int *, nss_module_unregister_fn *);
454 #include "nss_backends.h"
455 #undef NSS_BACKEND
456
457 static void
nss_load_builtin_modules(void)458 nss_load_builtin_modules(void)
459 {
460 #define NSS_BACKEND(name, reg) nss_load_module(#name, reg);
461 #include "nss_backends.h"
462 #undef NSS_BACKEND
463 }
464
465
466 /* Load a built-in or dynamically linked module. If the `reg_fn'
467 * argument is non-NULL, assume a built-in module and use reg_fn to
468 * register it. Otherwise, search for a dynamic NSS module.
469 */
470 static void
nss_load_module(const char * source,nss_module_register_fn reg_fn)471 nss_load_module(const char *source, nss_module_register_fn reg_fn)
472 {
473 char buf[PATH_MAX];
474 ns_mod mod;
475 nss_module_register_fn fn;
476
477 memset(&mod, 0, sizeof(mod));
478 mod.name = strdup(source);
479 if (mod.name == NULL) {
480 nss_log_simple(LOG_ERR, "memory allocation failure");
481 return;
482 }
483 if (reg_fn != NULL) {
484 /* The placeholder is required, as a NULL handle
485 * represents an invalid module.
486 */
487 mod.handle = nss_builtin_handle;
488 fn = reg_fn;
489 } else if (!is_dynamic()) {
490 goto fin;
491 } else if (strcmp(source, NSSRC_CACHE) == 0 ||
492 strcmp(source, NSSRC_COMPAT) == 0 ||
493 strcmp(source, NSSRC_DB) == 0 ||
494 strcmp(source, NSSRC_DNS) == 0 ||
495 strcmp(source, NSSRC_FILES) == 0 ||
496 strcmp(source, NSSRC_NIS) == 0) {
497 /*
498 * Avoid calling dlopen(3) for built-in modules.
499 */
500 goto fin;
501 } else {
502 if (snprintf(buf, sizeof(buf), "nss_%s.so.%d", mod.name,
503 NSS_MODULE_INTERFACE_VERSION) >= (int)sizeof(buf))
504 goto fin;
505 mod.handle = libc_dlopen(buf, RTLD_LOCAL|RTLD_LAZY);
506 if (mod.handle == NULL) {
507 #ifdef _NSS_DEBUG
508 /* This gets pretty annoying since the built-in
509 * sources aren't modules yet.
510 */
511 nss_log(LOG_DEBUG, "%s, %s", mod.name, dlerror());
512 #endif
513 goto fin;
514 }
515 fn = (nss_module_register_fn)dlfunc(mod.handle,
516 "nss_module_register");
517 if (fn == NULL) {
518 (void)dlclose(mod.handle);
519 mod.handle = NULL;
520 nss_log(LOG_ERR, "%s, %s", mod.name, dlerror());
521 goto fin;
522 }
523 }
524 mod.mtab = fn(mod.name, &mod.mtabsize, &mod.unregister);
525 if (mod.mtab == NULL || mod.mtabsize == 0) {
526 if (mod.handle != nss_builtin_handle)
527 (void)dlclose(mod.handle);
528 mod.handle = NULL;
529 nss_log(LOG_ERR, "%s, registration failed", mod.name);
530 goto fin;
531 }
532 if (mod.mtabsize > 1)
533 qsort(mod.mtab, mod.mtabsize, sizeof(mod.mtab[0]),
534 mtab_compare);
535 fin:
536 _nsmod = vector_append(&mod, _nsmod, &_nsmodsize, sizeof(*_nsmod));
537 vector_sort(_nsmod, _nsmodsize, sizeof(*_nsmod), string_compare);
538 }
539
540 static int exiting = 0;
541
542 static void
ns_mod_free(ns_mod * mod)543 ns_mod_free(ns_mod *mod)
544 {
545
546 free(mod->name);
547 if (mod->handle == NULL)
548 return;
549 if (mod->unregister != NULL)
550 mod->unregister(mod->mtab, mod->mtabsize);
551 if (mod->handle != nss_builtin_handle && !exiting)
552 (void)dlclose(mod->handle);
553 }
554
555 /*
556 * Cleanup
557 */
558 static void
nss_atexit(void)559 nss_atexit(void)
560 {
561 int isthreaded;
562
563 exiting = 1;
564 isthreaded = __isthreaded;
565 if (isthreaded)
566 (void)_pthread_rwlock_wrlock(&nss_lock);
567 VECTOR_FREE(_nsmap, &_nsmapsize, sizeof(*_nsmap),
568 (vector_free_elem)ns_dbt_free);
569 VECTOR_FREE(_nsmod, &_nsmodsize, sizeof(*_nsmod),
570 (vector_free_elem)ns_mod_free);
571 if (isthreaded)
572 (void)_pthread_rwlock_unlock(&nss_lock);
573 }
574
575 /*
576 * Finally, the actual implementation.
577 */
578 static nss_method
nss_method_lookup(const char * source,const char * database,const char * method,const ns_dtab disp_tab[],void ** mdata)579 nss_method_lookup(const char *source, const char *database,
580 const char *method, const ns_dtab disp_tab[], void **mdata)
581 {
582 ns_mod *mod;
583 ns_mtab *match, key;
584 int i;
585
586 if (disp_tab != NULL)
587 for (i = 0; disp_tab[i].src != NULL; i++)
588 if (strcasecmp(source, disp_tab[i].src) == 0) {
589 *mdata = disp_tab[i].mdata;
590 return (disp_tab[i].method);
591 }
592 mod = vector_search(&source, _nsmod, _nsmodsize, sizeof(*_nsmod),
593 string_compare);
594 if (mod != NULL && mod->handle != NULL) {
595 key.database = database;
596 key.name = method;
597 match = bsearch(&key, mod->mtab, mod->mtabsize,
598 sizeof(mod->mtab[0]), mtab_compare);
599 if (match != NULL) {
600 *mdata = match->mdata;
601 return (match->method);
602 }
603 }
604
605 *mdata = NULL;
606 return (NULL);
607 }
608
609 static void
fb_endstate(void * p)610 fb_endstate(void *p)
611 {
612 free(p);
613 }
614
615 __weak_reference(_nsdispatch, nsdispatch);
616
617 int
_nsdispatch(void * retval,const ns_dtab disp_tab[],const char * database,const char * method_name,const ns_src defaults[],...)618 _nsdispatch(void *retval, const ns_dtab disp_tab[], const char *database,
619 const char *method_name, const ns_src defaults[], ...)
620 {
621 va_list ap;
622 const ns_dbt *dbt;
623 const ns_src *srclist;
624 nss_method method, fb_method;
625 void *mdata;
626 int isthreaded, serrno, i, result, srclistsize;
627 struct fb_state *st;
628 int saved_depth;
629
630 #ifdef NS_CACHING
631 nss_cache_data cache_data;
632 nss_cache_data *cache_data_p;
633 int cache_flag;
634 #endif
635
636 dbt = NULL;
637 fb_method = NULL;
638
639 isthreaded = __isthreaded;
640 serrno = errno;
641 if (isthreaded) {
642 result = _pthread_rwlock_rdlock(&nss_lock);
643 if (result != 0) {
644 result = NS_UNAVAIL;
645 goto fin;
646 }
647 }
648
649 result = fb_getstate(&st);
650 if (result != 0) {
651 result = NS_UNAVAIL;
652 goto fin;
653 }
654
655 result = nss_configure();
656 if (result != 0) {
657 result = NS_UNAVAIL;
658 goto fin;
659 }
660 ++st->dispatch_depth;
661 if (st->dispatch_depth > st->fallback_depth) {
662 dbt = vector_search(&database, _nsmap, _nsmapsize, sizeof(*_nsmap),
663 string_compare);
664 fb_method = nss_method_lookup(NSSRC_FALLBACK, database,
665 method_name, disp_tab, &mdata);
666 }
667
668 if (dbt != NULL) {
669 srclist = dbt->srclist;
670 srclistsize = dbt->srclistsize;
671 } else {
672 srclist = defaults;
673 srclistsize = 0;
674 while (srclist[srclistsize].name != NULL)
675 srclistsize++;
676 }
677
678 #ifdef NS_CACHING
679 cache_data_p = NULL;
680 cache_flag = 0;
681 #endif
682 for (i = 0; i < srclistsize; i++) {
683 result = NS_NOTFOUND;
684 method = nss_method_lookup(srclist[i].name, database,
685 method_name, disp_tab, &mdata);
686
687 if (method != NULL) {
688 #ifdef NS_CACHING
689 if (strcmp(srclist[i].name, NSSRC_CACHE) == 0 &&
690 nss_cache_cycle_prevention_func == NULL) {
691 #ifdef NS_STRICT_LIBC_EID_CHECKING
692 if (issetugid() != 0)
693 continue;
694 #endif
695 cache_flag = 1;
696
697 memset(&cache_data, 0, sizeof(nss_cache_data));
698 cache_data.info = (nss_cache_info const *)mdata;
699 cache_data_p = &cache_data;
700
701 va_start(ap, defaults);
702 if (cache_data.info->id_func != NULL)
703 result = __nss_common_cache_read(retval,
704 cache_data_p, ap);
705 else if (cache_data.info->marshal_func != NULL)
706 result = __nss_mp_cache_read(retval,
707 cache_data_p, ap);
708 else
709 result = __nss_mp_cache_end(retval,
710 cache_data_p, ap);
711 va_end(ap);
712 } else {
713 cache_flag = 0;
714 errno = 0;
715 va_start(ap, defaults);
716 result = method(retval, mdata, ap);
717 va_end(ap);
718 }
719 #else /* NS_CACHING */
720 errno = 0;
721 va_start(ap, defaults);
722 result = method(retval, mdata, ap);
723 va_end(ap);
724 #endif /* NS_CACHING */
725
726 if (result & (srclist[i].flags))
727 break;
728 } else {
729 if (fb_method != NULL) {
730 saved_depth = st->fallback_depth;
731 st->fallback_depth = st->dispatch_depth + 1;
732 va_start(ap, defaults);
733 result = fb_method(retval,
734 (void *)srclist[i].name, ap);
735 va_end(ap);
736 st->fallback_depth = saved_depth;
737 } else
738 nss_log(LOG_DEBUG, "%s, %s, %s, not found, "
739 "and no fallback provided",
740 srclist[i].name, database, method_name);
741 }
742 }
743
744 #ifdef NS_CACHING
745 if (cache_data_p != NULL &&
746 (result & (NS_NOTFOUND | NS_SUCCESS)) && cache_flag == 0) {
747 va_start(ap, defaults);
748 if (result == NS_SUCCESS) {
749 if (cache_data.info->id_func != NULL)
750 __nss_common_cache_write(retval, cache_data_p,
751 ap);
752 else if (cache_data.info->marshal_func != NULL)
753 __nss_mp_cache_write(retval, cache_data_p, ap);
754 } else if (result == NS_NOTFOUND) {
755 if (cache_data.info->id_func == NULL) {
756 if (cache_data.info->marshal_func != NULL)
757 __nss_mp_cache_write_submit(retval,
758 cache_data_p, ap);
759 } else
760 __nss_common_cache_write_negative(cache_data_p);
761 }
762 va_end(ap);
763 }
764 #endif /* NS_CACHING */
765
766 if (isthreaded)
767 (void)_pthread_rwlock_unlock(&nss_lock);
768 --st->dispatch_depth;
769 fin:
770 errno = serrno;
771 return (result);
772 }
773