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