1 /* $NetBSD: nsdispatch.c,v 1.9 1999/01/25 00:16:17 lukem Exp $ */
2
3 /*-
4 * SPDX-License-Identifier: BSD-2-Clause
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 "namespace.h"
66 #include <sys/param.h>
67 #include <sys/stat.h>
68
69 #include <dlfcn.h>
70 #include <errno.h>
71 #include <fcntl.h>
72 #define _NS_PRIVATE
73 #include <nsswitch.h>
74 #include <pthread.h>
75 #include <pthread_np.h>
76 #include <stdio.h>
77 #include <stdlib.h>
78 #include <string.h>
79 #include <syslog.h>
80 #include <unistd.h>
81 #include "un-namespace.h"
82 #include "nss_tls.h"
83 #include "libc_private.h"
84 #ifdef NS_CACHING
85 #include "nscache.h"
86 #endif
87
88 enum _nss_constants {
89 /* Number of elements allocated when we grow a vector */
90 ELEMSPERCHUNK = 8
91 };
92
93 /*
94 * Global NSS data structures are mostly read-only, but we update
95 * them when we read or re-read the nsswitch.conf.
96 */
97 static pthread_rwlock_t nss_lock = PTHREAD_RWLOCK_INITIALIZER;
98
99 /*
100 * Runtime determination of whether we are dynamically linked or not.
101 */
102 extern int _DYNAMIC __attribute__ ((weak));
103 #define is_dynamic() (&_DYNAMIC != NULL)
104
105 /*
106 * default sourcelist: `files'
107 */
108 const ns_src __nsdefaultsrc[] = {
109 { NSSRC_FILES, NS_SUCCESS },
110 { 0 },
111 };
112
113 /* Database, source mappings. */
114 static unsigned int _nsmapsize;
115 static ns_dbt *_nsmap = NULL;
116
117 /* NSS modules. */
118 static unsigned int _nsmodsize;
119 static ns_mod *_nsmod;
120
121 /* Placeholder for builtin modules' dlopen `handle'. */
122 static int __nss_builtin_handle;
123 static void *nss_builtin_handle = &__nss_builtin_handle;
124
125 #ifdef NS_CACHING
126 /*
127 * Cache lookup cycle prevention function - if !NULL then no cache lookups
128 * will be made
129 */
130 static void *nss_cache_cycle_prevention_func = NULL;
131 #endif
132
133 /*
134 * We keep track of nsdispatch() nesting depth in dispatch_depth. When a
135 * fallback method is invoked from nsdispatch(), we temporarily set
136 * fallback_depth to the current dispatch depth plus one. Subsequent
137 * calls at that exact depth will run in fallback mode (restricted to the
138 * same source as the call that was handled by the fallback method), while
139 * calls below that depth will be handled normally, allowing fallback
140 * methods to perform arbitrary lookups.
141 */
142 struct fb_state {
143 int dispatch_depth;
144 int fallback_depth;
145 };
146 static void fb_endstate(void *);
147 NSS_TLS_HANDLING(fb);
148
149 /*
150 * Attempt to spew relatively uniform messages to syslog.
151 */
152 #define nss_log(level, fmt, ...) \
153 syslog((level), "NSSWITCH(%s): " fmt, __func__, __VA_ARGS__)
154 #define nss_log_simple(level, s) \
155 syslog((level), "NSSWITCH(%s): " s, __func__)
156
157 /*
158 * Dynamically growable arrays are used for lists of databases, sources,
159 * and modules. The following `vector' interface is used to isolate the
160 * common operations.
161 */
162 typedef int (*vector_comparison)(const void *, const void *);
163 typedef void (*vector_free_elem)(void *);
164 static void vector_sort(void *, unsigned int, size_t,
165 vector_comparison);
166 static void vector_free(void *, unsigned int *, size_t,
167 vector_free_elem);
168 static void *vector_ref(unsigned int, void *, unsigned int, size_t);
169 static void *vector_search(const void *, void *, unsigned int, size_t,
170 vector_comparison);
171 static void *vector_append(const void *, void *, unsigned int *, size_t);
172
173
174 /*
175 * Internal interfaces.
176 */
177 static int string_compare(const void *, const void *);
178 static int mtab_compare(const void *, const void *);
179 static int nss_configure(void);
180 static void ns_dbt_free(ns_dbt *);
181 static void ns_mod_free(ns_mod *);
182 static void ns_src_free(ns_src **, int);
183 static void nss_load_builtin_modules(void);
184 static void nss_load_module(const char *, nss_module_register_fn);
185 static void nss_atexit(void);
186 /* nsparser */
187 extern FILE *_nsyyin;
188
189
190 /*
191 * The vector operations
192 */
193 static void
vector_sort(void * vec,unsigned int count,size_t esize,vector_comparison comparison)194 vector_sort(void *vec, unsigned int count, size_t esize,
195 vector_comparison comparison)
196 {
197 qsort(vec, count, esize, comparison);
198 }
199
200
201 static void *
vector_search(const void * key,void * vec,unsigned int count,size_t esize,vector_comparison comparison)202 vector_search(const void *key, void *vec, unsigned int count, size_t esize,
203 vector_comparison comparison)
204 {
205 return (bsearch(key, vec, count, esize, comparison));
206 }
207
208
209 static void *
vector_append(const void * elem,void * vec,unsigned int * count,size_t esize)210 vector_append(const void *elem, void *vec, unsigned int *count, size_t esize)
211 {
212 void *p;
213
214 if ((*count % ELEMSPERCHUNK) == 0) {
215 p = reallocarray(vec, *count + ELEMSPERCHUNK, esize);
216 if (p == NULL) {
217 nss_log_simple(LOG_ERR, "memory allocation failure");
218 return (vec);
219 }
220 vec = p;
221 }
222 memmove((void *)(((uintptr_t)vec) + (*count * esize)), elem, esize);
223 (*count)++;
224 return (vec);
225 }
226
227
228 static void *
vector_ref(unsigned int i,void * vec,unsigned int count,size_t esize)229 vector_ref(unsigned int i, void *vec, unsigned int count, size_t esize)
230 {
231 if (i < count)
232 return (void *)((uintptr_t)vec + (i * esize));
233 else
234 return (NULL);
235 }
236
237
238 #define VECTOR_FREE(v, c, s, f) \
239 do { vector_free(v, c, s, f); v = NULL; } while (0)
240 static void
vector_free(void * vec,unsigned int * count,size_t esize,vector_free_elem free_elem)241 vector_free(void *vec, unsigned int *count, size_t esize,
242 vector_free_elem free_elem)
243 {
244 unsigned int i;
245 void *elem;
246
247 for (i = 0; i < *count; i++) {
248 elem = vector_ref(i, vec, *count, esize);
249 if (elem != NULL)
250 free_elem(elem);
251 }
252 free(vec);
253 *count = 0;
254 }
255
256 /*
257 * Comparison functions for vector_search.
258 */
259 static int
string_compare(const void * a,const void * b)260 string_compare(const void *a, const void *b)
261 {
262 return (strcasecmp(*(const char * const *)a, *(const char * const *)b));
263 }
264
265
266 static int
mtab_compare(const void * a,const void * b)267 mtab_compare(const void *a, const void *b)
268 {
269 int cmp;
270
271 cmp = strcmp(((const ns_mtab *)a)->name, ((const ns_mtab *)b)->name);
272 if (cmp != 0)
273 return (cmp);
274 else
275 return (strcmp(((const ns_mtab *)a)->database,
276 ((const ns_mtab *)b)->database));
277 }
278
279 /*
280 * NSS nsmap management.
281 */
282 void
_nsdbtaddsrc(ns_dbt * dbt,const ns_src * src)283 _nsdbtaddsrc(ns_dbt *dbt, const ns_src *src)
284 {
285 const ns_mod *modp;
286
287 dbt->srclist = vector_append(src, dbt->srclist, &dbt->srclistsize,
288 sizeof(*src));
289 modp = vector_search(&src->name, _nsmod, _nsmodsize, sizeof(*_nsmod),
290 string_compare);
291 if (modp == NULL)
292 nss_load_module(src->name, NULL);
293 }
294
295
296 #ifdef _NSS_DEBUG
297 void
_nsdbtdump(const ns_dbt * dbt)298 _nsdbtdump(const ns_dbt *dbt)
299 {
300 int i;
301
302 printf("%s (%d source%s):", dbt->name, dbt->srclistsize,
303 dbt->srclistsize == 1 ? "" : "s");
304 for (i = 0; i < (int)dbt->srclistsize; i++) {
305 printf(" %s", dbt->srclist[i].name);
306 if (!(dbt->srclist[i].flags &
307 (NS_UNAVAIL|NS_NOTFOUND|NS_TRYAGAIN)) &&
308 (dbt->srclist[i].flags & NS_SUCCESS))
309 continue;
310 printf(" [");
311 if (!(dbt->srclist[i].flags & NS_SUCCESS))
312 printf(" SUCCESS=continue");
313 if (dbt->srclist[i].flags & NS_UNAVAIL)
314 printf(" UNAVAIL=return");
315 if (dbt->srclist[i].flags & NS_NOTFOUND)
316 printf(" NOTFOUND=return");
317 if (dbt->srclist[i].flags & NS_TRYAGAIN)
318 printf(" TRYAGAIN=return");
319 printf(" ]");
320 }
321 printf("\n");
322 }
323 #endif
324
325
326 /*
327 * The first time nsdispatch is called (during a process's lifetime,
328 * or after nsswitch.conf has been updated), nss_configure will
329 * prepare global data needed by NSS.
330 */
331 static int
nss_configure(void)332 nss_configure(void)
333 {
334 static time_t confmod;
335 #ifndef NS_REREAD_CONF
336 static int already_initialized = 0;
337 #endif
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 #ifndef NS_REREAD_CONF
356 /*
357 * Define NS_REREAD_CONF to have nsswitch notice changes
358 * to nsswitch.conf(5) during runtime. This involves calling
359 * stat(2) every time, which can result in performance hit.
360 */
361 if (already_initialized)
362 return (0);
363 already_initialized = 1;
364 #endif /* NS_REREAD_CONF */
365 if (stat(path, &statbuf) != 0)
366 return (0);
367 if (statbuf.st_mtime <= confmod)
368 return (0);
369 if (isthreaded) {
370 (void)_pthread_rwlock_unlock(&nss_lock);
371 result = _pthread_rwlock_wrlock(&nss_lock);
372 if (result != 0)
373 return (result);
374 if (stat(path, &statbuf) != 0)
375 goto fin;
376 if (statbuf.st_mtime <= confmod)
377 goto fin;
378 }
379 _nsyyin = fopen(path, "re");
380 if (_nsyyin == NULL)
381 goto fin;
382 VECTOR_FREE(_nsmap, &_nsmapsize, sizeof(*_nsmap),
383 (vector_free_elem)ns_dbt_free);
384 VECTOR_FREE(_nsmod, &_nsmodsize, sizeof(*_nsmod),
385 (vector_free_elem)ns_mod_free);
386 if (confmod == 0)
387 (void)atexit(nss_atexit);
388 nss_load_builtin_modules();
389 _nsyyparse();
390 (void)fclose(_nsyyin);
391 vector_sort(_nsmap, _nsmapsize, sizeof(*_nsmap), string_compare);
392 confmod = statbuf.st_mtime;
393
394 #ifdef NS_CACHING
395 handle = libc_dlopen(NULL, RTLD_LAZY | RTLD_GLOBAL);
396 if (handle != NULL) {
397 nss_cache_cycle_prevention_func = dlsym(handle,
398 "_nss_cache_cycle_prevention_function");
399 dlclose(handle);
400 }
401 #endif
402 fin:
403 if (isthreaded) {
404 (void)_pthread_rwlock_unlock(&nss_lock);
405 if (result == 0)
406 result = _pthread_rwlock_rdlock(&nss_lock);
407 }
408 return (result);
409 }
410
411
412 void
_nsdbtput(const ns_dbt * dbt)413 _nsdbtput(const ns_dbt *dbt)
414 {
415 unsigned int i;
416 ns_dbt *p;
417
418 for (i = 0; i < _nsmapsize; i++) {
419 p = vector_ref(i, _nsmap, _nsmapsize, sizeof(*_nsmap));
420 if (string_compare(&dbt->name, &p->name) == 0) {
421 /* overwrite existing entry */
422 if (p->srclist != NULL)
423 ns_src_free(&p->srclist, p->srclistsize);
424 memmove(p, dbt, sizeof(*dbt));
425 return;
426 }
427 }
428 _nsmap = vector_append(dbt, _nsmap, &_nsmapsize, sizeof(*_nsmap));
429 }
430
431
432 static void
ns_dbt_free(ns_dbt * dbt)433 ns_dbt_free(ns_dbt *dbt)
434 {
435 ns_src_free(&dbt->srclist, dbt->srclistsize);
436 if (dbt->name)
437 free((void *)dbt->name);
438 }
439
440
441 static void
ns_src_free(ns_src ** src,int srclistsize)442 ns_src_free(ns_src **src, int srclistsize)
443 {
444 int i;
445
446 for (i = 0; i < srclistsize; i++)
447 if ((*src)[i].name != NULL)
448 /* This one was allocated by nslexer. You'll just
449 * have to trust me.
450 */
451 free((void *)((*src)[i].name));
452 free(*src);
453 *src = NULL;
454 }
455
456
457
458 /*
459 * NSS module management.
460 */
461 /* The built-in NSS modules are all loaded at once. */
462 #define NSS_BACKEND(name, reg) \
463 ns_mtab *reg(unsigned int *, nss_module_unregister_fn *);
464 #include "nss_backends.h"
465 #undef NSS_BACKEND
466
467 static void
nss_load_builtin_modules(void)468 nss_load_builtin_modules(void)
469 {
470 #define NSS_BACKEND(name, reg) nss_load_module(#name, reg);
471 #include "nss_backends.h"
472 #undef NSS_BACKEND
473 }
474
475
476 /* Load a built-in or dynamically linked module. If the `reg_fn'
477 * argument is non-NULL, assume a built-in module and use reg_fn to
478 * register it. Otherwise, search for a dynamic NSS module.
479 */
480 static void
nss_load_module(const char * source,nss_module_register_fn reg_fn)481 nss_load_module(const char *source, nss_module_register_fn reg_fn)
482 {
483 char buf[PATH_MAX];
484 ns_mod mod;
485 nss_module_register_fn fn;
486
487 memset(&mod, 0, sizeof(mod));
488 mod.name = strdup(source);
489 if (mod.name == NULL) {
490 nss_log_simple(LOG_ERR, "memory allocation failure");
491 return;
492 }
493 if (reg_fn != NULL) {
494 /* The placeholder is required, as a NULL handle
495 * represents an invalid module.
496 */
497 mod.handle = nss_builtin_handle;
498 fn = reg_fn;
499 } else if (!is_dynamic()) {
500 goto fin;
501 } else if (strcmp(source, NSSRC_CACHE) == 0 ||
502 strcmp(source, NSSRC_COMPAT) == 0 ||
503 strcmp(source, NSSRC_DB) == 0 ||
504 strcmp(source, NSSRC_DNS) == 0 ||
505 strcmp(source, NSSRC_FILES) == 0 ||
506 strcmp(source, NSSRC_NIS) == 0) {
507 /*
508 * Avoid calling dlopen(3) for built-in modules.
509 */
510 goto fin;
511 } else {
512 if (snprintf(buf, sizeof(buf), "nss_%s.so.%d", mod.name,
513 NSS_MODULE_INTERFACE_VERSION) >= (int)sizeof(buf))
514 goto fin;
515 mod.handle = libc_dlopen(buf, RTLD_LOCAL|RTLD_LAZY);
516 if (mod.handle == NULL) {
517 #ifdef _NSS_DEBUG
518 /* This gets pretty annoying since the built-in
519 * sources aren't modules yet.
520 */
521 nss_log(LOG_DEBUG, "%s, %s", mod.name, dlerror());
522 #endif
523 goto fin;
524 }
525 fn = (nss_module_register_fn)dlfunc(mod.handle,
526 "nss_module_register");
527 if (fn == NULL) {
528 (void)dlclose(mod.handle);
529 mod.handle = NULL;
530 nss_log(LOG_ERR, "%s, %s", mod.name, dlerror());
531 goto fin;
532 }
533 }
534 mod.mtab = fn(mod.name, &mod.mtabsize, &mod.unregister);
535 if (mod.mtab == NULL || mod.mtabsize == 0) {
536 if (mod.handle != nss_builtin_handle)
537 (void)dlclose(mod.handle);
538 mod.handle = NULL;
539 nss_log(LOG_ERR, "%s, registration failed", mod.name);
540 goto fin;
541 }
542 if (mod.mtabsize > 1)
543 qsort(mod.mtab, mod.mtabsize, sizeof(mod.mtab[0]),
544 mtab_compare);
545 fin:
546 _nsmod = vector_append(&mod, _nsmod, &_nsmodsize, sizeof(*_nsmod));
547 vector_sort(_nsmod, _nsmodsize, sizeof(*_nsmod), string_compare);
548 }
549
550 static int exiting = 0;
551
552 static void
ns_mod_free(ns_mod * mod)553 ns_mod_free(ns_mod *mod)
554 {
555
556 free(mod->name);
557 if (mod->handle == NULL)
558 return;
559 if (mod->unregister != NULL)
560 mod->unregister(mod->mtab, mod->mtabsize);
561 if (mod->handle != nss_builtin_handle && !exiting)
562 (void)dlclose(mod->handle);
563 }
564
565 /*
566 * Cleanup
567 */
568 static void
nss_atexit(void)569 nss_atexit(void)
570 {
571 int isthreaded;
572
573 exiting = 1;
574 isthreaded = __isthreaded;
575 if (isthreaded)
576 (void)_pthread_rwlock_wrlock(&nss_lock);
577 VECTOR_FREE(_nsmap, &_nsmapsize, sizeof(*_nsmap),
578 (vector_free_elem)ns_dbt_free);
579 VECTOR_FREE(_nsmod, &_nsmodsize, sizeof(*_nsmod),
580 (vector_free_elem)ns_mod_free);
581 if (isthreaded)
582 (void)_pthread_rwlock_unlock(&nss_lock);
583 }
584
585 /*
586 * Finally, the actual implementation.
587 */
588 static nss_method
nss_method_lookup(const char * source,const char * database,const char * method,const ns_dtab disp_tab[],void ** mdata)589 nss_method_lookup(const char *source, const char *database,
590 const char *method, const ns_dtab disp_tab[], void **mdata)
591 {
592 ns_mod *mod;
593 ns_mtab *match, key;
594 int i;
595
596 if (disp_tab != NULL)
597 for (i = 0; disp_tab[i].src != NULL; i++)
598 if (strcasecmp(source, disp_tab[i].src) == 0) {
599 *mdata = disp_tab[i].mdata;
600 return (disp_tab[i].method);
601 }
602 mod = vector_search(&source, _nsmod, _nsmodsize, sizeof(*_nsmod),
603 string_compare);
604 if (mod != NULL && mod->handle != NULL) {
605 key.database = database;
606 key.name = method;
607 match = bsearch(&key, mod->mtab, mod->mtabsize,
608 sizeof(mod->mtab[0]), mtab_compare);
609 if (match != NULL) {
610 *mdata = match->mdata;
611 return (match->method);
612 }
613 }
614
615 *mdata = NULL;
616 return (NULL);
617 }
618
619 static void
fb_endstate(void * p)620 fb_endstate(void *p)
621 {
622 free(p);
623 }
624
625 __weak_reference(_nsdispatch, nsdispatch);
626
627 int
_nsdispatch(void * retval,const ns_dtab disp_tab[],const char * database,const char * method_name,const ns_src defaults[],...)628 _nsdispatch(void *retval, const ns_dtab disp_tab[], const char *database,
629 const char *method_name, const ns_src defaults[], ...)
630 {
631 va_list ap;
632 const ns_dbt *dbt;
633 const ns_src *srclist;
634 nss_method method, fb_method;
635 void *mdata;
636 int isthreaded, serrno, i, result, srclistsize;
637 struct fb_state *st;
638 int saved_depth;
639
640 #ifdef NS_CACHING
641 nss_cache_data cache_data;
642 nss_cache_data *cache_data_p;
643 int cache_flag;
644 #endif
645
646 dbt = NULL;
647 fb_method = NULL;
648
649 isthreaded = __isthreaded;
650 serrno = errno;
651 if (isthreaded) {
652 result = _pthread_rwlock_rdlock(&nss_lock);
653 if (result != 0) {
654 result = NS_UNAVAIL;
655 goto fin;
656 }
657 }
658
659 result = fb_getstate(&st);
660 if (result != 0) {
661 result = NS_UNAVAIL;
662 goto fin;
663 }
664
665 result = nss_configure();
666 if (result != 0) {
667 result = NS_UNAVAIL;
668 goto fin;
669 }
670 ++st->dispatch_depth;
671 if (st->dispatch_depth > st->fallback_depth) {
672 dbt = vector_search(&database, _nsmap, _nsmapsize, sizeof(*_nsmap),
673 string_compare);
674 fb_method = nss_method_lookup(NSSRC_FALLBACK, database,
675 method_name, disp_tab, &mdata);
676 }
677
678 if (dbt != NULL) {
679 srclist = dbt->srclist;
680 srclistsize = dbt->srclistsize;
681 } else {
682 srclist = defaults;
683 srclistsize = 0;
684 while (srclist[srclistsize].name != NULL)
685 srclistsize++;
686 }
687
688 #ifdef NS_CACHING
689 cache_data_p = NULL;
690 cache_flag = 0;
691 #endif
692 for (i = 0; i < srclistsize; i++) {
693 result = NS_NOTFOUND;
694 method = nss_method_lookup(srclist[i].name, database,
695 method_name, disp_tab, &mdata);
696
697 if (method != NULL) {
698 #ifdef NS_CACHING
699 if (strcmp(srclist[i].name, NSSRC_CACHE) == 0 &&
700 nss_cache_cycle_prevention_func == NULL) {
701 #ifdef NS_STRICT_LIBC_EID_CHECKING
702 if (issetugid() != 0)
703 continue;
704 #endif
705 cache_flag = 1;
706
707 memset(&cache_data, 0, sizeof(nss_cache_data));
708 cache_data.info = (nss_cache_info const *)mdata;
709 cache_data_p = &cache_data;
710
711 va_start(ap, defaults);
712 if (cache_data.info->id_func != NULL)
713 result = __nss_common_cache_read(retval,
714 cache_data_p, ap);
715 else if (cache_data.info->marshal_func != NULL)
716 result = __nss_mp_cache_read(retval,
717 cache_data_p, ap);
718 else
719 result = __nss_mp_cache_end(retval,
720 cache_data_p, ap);
721 va_end(ap);
722 } else {
723 cache_flag = 0;
724 errno = 0;
725 va_start(ap, defaults);
726 result = method(retval, mdata, ap);
727 va_end(ap);
728 }
729 #else /* NS_CACHING */
730 errno = 0;
731 va_start(ap, defaults);
732 result = method(retval, mdata, ap);
733 va_end(ap);
734 #endif /* NS_CACHING */
735
736 if (result & (srclist[i].flags))
737 break;
738 } else {
739 if (fb_method != NULL) {
740 saved_depth = st->fallback_depth;
741 st->fallback_depth = st->dispatch_depth + 1;
742 va_start(ap, defaults);
743 result = fb_method(retval,
744 (void *)srclist[i].name, ap);
745 va_end(ap);
746 st->fallback_depth = saved_depth;
747 } else
748 nss_log(LOG_DEBUG, "%s, %s, %s, not found, "
749 "and no fallback provided",
750 srclist[i].name, database, method_name);
751 }
752 }
753
754 #ifdef NS_CACHING
755 if (cache_data_p != NULL &&
756 (result & (NS_NOTFOUND | NS_SUCCESS)) && cache_flag == 0) {
757 va_start(ap, defaults);
758 if (result == NS_SUCCESS) {
759 if (cache_data.info->id_func != NULL)
760 __nss_common_cache_write(retval, cache_data_p,
761 ap);
762 else if (cache_data.info->marshal_func != NULL)
763 __nss_mp_cache_write(retval, cache_data_p, ap);
764 } else if (result == NS_NOTFOUND) {
765 if (cache_data.info->id_func == NULL) {
766 if (cache_data.info->marshal_func != NULL)
767 __nss_mp_cache_write_submit(retval,
768 cache_data_p, ap);
769 } else
770 __nss_common_cache_write_negative(cache_data_p);
771 }
772 va_end(ap);
773 }
774 #endif /* NS_CACHING */
775
776 if (isthreaded)
777 (void)_pthread_rwlock_unlock(&nss_lock);
778 --st->dispatch_depth;
779 fin:
780 errno = serrno;
781 return (result);
782 }
783