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
88enum _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 */
97static	pthread_rwlock_t	nss_lock = PTHREAD_RWLOCK_INITIALIZER;
98
99/*
100 * Runtime determination of whether we are dynamically linked or not.
101 */
102extern	int		_DYNAMIC __attribute__ ((weak));
103#define	is_dynamic()	(&_DYNAMIC != NULL)
104
105/*
106 * default sourcelist: `files'
107 */
108const ns_src __nsdefaultsrc[] = {
109	{ NSSRC_FILES, NS_SUCCESS },
110	{ 0 },
111};
112
113/* Database, source mappings. */
114static	unsigned int		 _nsmapsize;
115static	ns_dbt			*_nsmap = NULL;
116
117/* NSS modules. */
118static	unsigned int		 _nsmodsize;
119static	ns_mod			*_nsmod;
120
121/* Placeholder for builtin modules' dlopen `handle'. */
122static	int			 __nss_builtin_handle;
123static	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 */
130static	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 */
142struct fb_state {
143	int	dispatch_depth;
144	int	fallback_depth;
145};
146static	void	fb_endstate(void *);
147NSS_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 */
162typedef	int	(*vector_comparison)(const void *, const void *);
163typedef	void	(*vector_free_elem)(void *);
164static	void	  vector_sort(void *, unsigned int, size_t,
165		    vector_comparison);
166static	void	  vector_free(void *, unsigned int *, size_t,
167		    vector_free_elem);
168static	void	 *vector_ref(unsigned int, void *, unsigned int, size_t);
169static	void	 *vector_search(const void *, void *, unsigned int, size_t,
170		    vector_comparison);
171static	void	 *vector_append(const void *, void *, unsigned int *, size_t);
172
173
174/*
175 * Internal interfaces.
176 */
177static	int	 string_compare(const void *, const void *);
178static	int	 mtab_compare(const void *, const void *);
179static	int	 nss_configure(void);
180static	void	 ns_dbt_free(ns_dbt *);
181static	void	 ns_mod_free(ns_mod *);
182static	void	 ns_src_free(ns_src **, int);
183static	void	 nss_load_builtin_modules(void);
184static	void	 nss_load_module(const char *, nss_module_register_fn);
185static	void	 nss_atexit(void);
186/* nsparser */
187extern	FILE	*_nsyyin;
188
189
190/*
191 * The vector operations
192 */
193static void
194vector_sort(void *vec, unsigned int count, size_t esize,
195    vector_comparison comparison)
196{
197	qsort(vec, count, esize, comparison);
198}
199
200
201static void *
202vector_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
209static void *
210vector_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
228static void *
229vector_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)
240static void
241vector_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 */
259static int
260string_compare(const void *a, const void *b)
261{
262      return (strcasecmp(*(const char * const *)a, *(const char * const *)b));
263}
264
265
266static int
267mtab_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 */
282void
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
297void
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 */
331static int
332nss_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
402fin:
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
412void
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
432static void
433ns_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
441static void
442ns_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) \
463ns_mtab	*reg(unsigned int *, nss_module_unregister_fn *);
464#include "nss_backends.h"
465#undef NSS_BACKEND
466
467static void
468nss_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 */
480static void
481nss_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);
545fin:
546	_nsmod = vector_append(&mod, _nsmod, &_nsmodsize, sizeof(*_nsmod));
547	vector_sort(_nsmod, _nsmodsize, sizeof(*_nsmod), string_compare);
548}
549
550static int exiting = 0;
551
552static void
553ns_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 */
568static void
569nss_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 */
588static nss_method
589nss_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
619static void
620fb_endstate(void *p)
621{
622	free(p);
623}
624
625__weak_reference(_nsdispatch, nsdispatch);
626
627int
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;
779fin:
780	errno = serrno;
781	return (result);
782}
783