1 /* $NetBSD: nsdispatch.c,v 1.9 1999/01/25 00:16:17 lukem Exp $ */
4 * Copyright (c) 1997, 1998, 1999 The NetBSD Foundation, Inc.
7 * This code is derived from software contributed to The NetBSD Foundation
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
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 * 3. All advertising materials mentioning features or use of this software
19 * must display the following acknowledgement:
20 * This product includes software developed by the NetBSD
21 * Foundation, Inc. and its contributors.
22 * 4. Neither the name of The NetBSD Foundation nor the names of its
23 * contributors may be used to endorse or promote products derived
24 * from this software without specific prior written permission.
26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36 * POSSIBILITY OF SUCH DAMAGE.
39 * Copyright (c) 2003 Networks Associates Technology, Inc.
40 * All rights reserved.
42 * Portions of this software were developed for the FreeBSD Project by
43 * Jacques A. Vidrine, Safeport Network Services, and Network
44 * Associates Laboratories, the Security Research Division of Network
45 * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035
46 * ("CBOSS"), as part of the DARPA CHATS research program.
48 * Redistribution and use in source and binary forms, with or without
49 * modification, are permitted provided that the following conditions
51 * 1. Redistributions of source code must retain the above copyright
52 * notice, this list of conditions and the following disclaimer.
53 * 2. Redistributions in binary form must reproduce the above copyright
54 * notice, this list of conditions and the following disclaimer in the
55 * documentation and/or other materials provided with the distribution.
57 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
58 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
59 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
60 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
61 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
62 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
63 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
64 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
65 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
66 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
70 #include <sys/cdefs.h>
71 __FBSDID("$FreeBSD$");
73 #include "namespace.h"
74 #include <sys/param.h>
88 #include "un-namespace.h"
89 #include "libc_private.h"
95 /* Number of elements allocated when we grow a vector */
100 * Global NSS data structures are mostly read-only, but we update
101 * them when we read or re-read the nsswitch.conf.
103 static pthread_rwlock_t nss_lock = PTHREAD_RWLOCK_INITIALIZER;
106 * Runtime determination of whether we are dynamically linked or not.
108 extern int _DYNAMIC __attribute__ ((weak));
109 #define is_dynamic() (&_DYNAMIC != NULL)
112 * default sourcelist: `files'
114 const ns_src __nsdefaultsrc[] = {
115 { NSSRC_FILES, NS_SUCCESS },
119 /* Database, source mappings. */
120 static unsigned int _nsmapsize;
121 static ns_dbt *_nsmap = NULL;
124 static unsigned int _nsmodsize;
125 static ns_mod *_nsmod;
127 /* Placeholder for builtin modules' dlopen `handle'. */
128 static int __nss_builtin_handle;
129 static void *nss_builtin_handle = &__nss_builtin_handle;
133 * Cache lookup cycle prevention function - if !NULL then no cache lookups
136 static void *nss_cache_cycle_prevention_func = NULL;
140 * Attempt to spew relatively uniform messages to syslog.
142 #define nss_log(level, fmt, ...) \
143 syslog((level), "NSSWITCH(%s): " fmt, __func__, __VA_ARGS__)
144 #define nss_log_simple(level, s) \
145 syslog((level), "NSSWITCH(%s): " s, __func__)
148 * Dynamically growable arrays are used for lists of databases, sources,
149 * and modules. The following `vector' interface is used to isolate the
152 typedef int (*vector_comparison)(const void *, const void *);
153 typedef void (*vector_free_elem)(void *);
154 static void vector_sort(void *, unsigned int, size_t,
156 static void vector_free(void *, unsigned int *, size_t,
158 static void *vector_ref(unsigned int, void *, unsigned int, size_t);
159 static void *vector_search(const void *, void *, unsigned int, size_t,
161 static void *vector_append(const void *, void *, unsigned int *, size_t);
165 * Internal interfaces.
167 static int string_compare(const void *, const void *);
168 static int mtab_compare(const void *, const void *);
169 static int nss_configure(void);
170 static void ns_dbt_free(ns_dbt *);
171 static void ns_mod_free(ns_mod *);
172 static void ns_src_free(ns_src **, int);
173 static void nss_load_builtin_modules(void);
174 static void nss_load_module(const char *, nss_module_register_fn);
175 static void nss_atexit(void);
177 extern FILE *_nsyyin;
181 * The vector operations
184 vector_sort(void *vec, unsigned int count, size_t esize,
185 vector_comparison comparison)
187 qsort(vec, count, esize, comparison);
192 vector_search(const void *key, void *vec, unsigned int count, size_t esize,
193 vector_comparison comparison)
195 return (bsearch(key, vec, count, esize, comparison));
200 vector_append(const void *elem, void *vec, unsigned int *count, size_t esize)
204 if ((*count % ELEMSPERCHUNK) == 0) {
205 p = realloc(vec, (*count + ELEMSPERCHUNK) * esize);
207 nss_log_simple(LOG_ERR, "memory allocation failure");
212 memmove((void *)(((uintptr_t)vec) + (*count * esize)), elem, esize);
219 vector_ref(unsigned int i, void *vec, unsigned int count, size_t esize)
222 return (void *)((uintptr_t)vec + (i * esize));
228 #define VECTOR_FREE(v, c, s, f) \
229 do { vector_free(v, c, s, f); v = NULL; } while (0)
231 vector_free(void *vec, unsigned int *count, size_t esize,
232 vector_free_elem free_elem)
237 for (i = 0; i < *count; i++) {
238 elem = vector_ref(i, vec, *count, esize);
247 * Comparison functions for vector_search.
250 string_compare(const void *a, const void *b)
252 return (strcasecmp(*(const char * const *)a, *(const char * const *)b));
257 mtab_compare(const void *a, const void *b)
261 cmp = strcmp(((const ns_mtab *)a)->name, ((const ns_mtab *)b)->name);
265 return (strcmp(((const ns_mtab *)a)->database,
266 ((const ns_mtab *)b)->database));
270 * NSS nsmap management.
273 _nsdbtaddsrc(ns_dbt *dbt, const ns_src *src)
277 dbt->srclist = vector_append(src, dbt->srclist, &dbt->srclistsize,
279 modp = vector_search(&src->name, _nsmod, _nsmodsize, sizeof(*_nsmod),
282 nss_load_module(src->name, NULL);
288 _nsdbtdump(const ns_dbt *dbt)
292 printf("%s (%d source%s):", dbt->name, dbt->srclistsize,
293 dbt->srclistsize == 1 ? "" : "s");
294 for (i = 0; i < (int)dbt->srclistsize; i++) {
295 printf(" %s", dbt->srclist[i].name);
296 if (!(dbt->srclist[i].flags &
297 (NS_UNAVAIL|NS_NOTFOUND|NS_TRYAGAIN)) &&
298 (dbt->srclist[i].flags & NS_SUCCESS))
301 if (!(dbt->srclist[i].flags & NS_SUCCESS))
302 printf(" SUCCESS=continue");
303 if (dbt->srclist[i].flags & NS_UNAVAIL)
304 printf(" UNAVAIL=return");
305 if (dbt->srclist[i].flags & NS_NOTFOUND)
306 printf(" NOTFOUND=return");
307 if (dbt->srclist[i].flags & NS_TRYAGAIN)
308 printf(" TRYAGAIN=return");
317 * The first time nsdispatch is called (during a process's lifetime,
318 * or after nsswitch.conf has been updated), nss_configure will
319 * prepare global data needed by NSS.
324 static pthread_mutex_t conf_lock = PTHREAD_MUTEX_INITIALIZER;
325 static time_t confmod;
327 int result, isthreaded;
334 isthreaded = __isthreaded;
335 #if defined(_NSS_DEBUG) && defined(_NSS_SHOOT_FOOT)
336 /* NOTE WELL: THIS IS A SECURITY HOLE. This must only be built
337 * for debugging purposes and MUST NEVER be used in production.
339 path = getenv("NSSWITCH_CONF");
342 path = _PATH_NS_CONF;
343 if (stat(path, &statbuf) != 0)
345 if (statbuf.st_mtime <= confmod)
348 result = _pthread_mutex_trylock(&conf_lock);
351 (void)_pthread_rwlock_unlock(&nss_lock);
352 result = _pthread_rwlock_wrlock(&nss_lock);
356 _nsyyin = fopen(path, "r");
359 VECTOR_FREE(_nsmap, &_nsmapsize, sizeof(*_nsmap),
360 (vector_free_elem)ns_dbt_free);
361 VECTOR_FREE(_nsmod, &_nsmodsize, sizeof(*_nsmod),
362 (vector_free_elem)ns_mod_free);
363 nss_load_builtin_modules();
365 (void)fclose(_nsyyin);
366 vector_sort(_nsmap, _nsmapsize, sizeof(*_nsmap), string_compare);
368 (void)atexit(nss_atexit);
369 confmod = statbuf.st_mtime;
372 handle = dlopen(NULL, RTLD_LAZY | RTLD_GLOBAL);
373 if (handle != NULL) {
374 nss_cache_cycle_prevention_func = dlsym(handle,
375 "_nss_cache_cycle_prevention_function");
381 (void)_pthread_rwlock_unlock(&nss_lock);
383 result = _pthread_rwlock_rdlock(&nss_lock);
387 (void)_pthread_mutex_unlock(&conf_lock);
393 _nsdbtput(const ns_dbt *dbt)
398 for (i = 0; i < _nsmapsize; i++) {
399 p = vector_ref(i, _nsmap, _nsmapsize, sizeof(*_nsmap));
400 if (string_compare(&dbt->name, &p->name) == 0) {
401 /* overwrite existing entry */
402 if (p->srclist != NULL)
403 ns_src_free(&p->srclist, p->srclistsize);
404 memmove(p, dbt, sizeof(*dbt));
408 _nsmap = vector_append(dbt, _nsmap, &_nsmapsize, sizeof(*_nsmap));
413 ns_dbt_free(ns_dbt *dbt)
415 ns_src_free(&dbt->srclist, dbt->srclistsize);
417 free((void *)dbt->name);
422 ns_src_free(ns_src **src, int srclistsize)
426 for (i = 0; i < srclistsize; i++)
427 if ((*src)[i].name != NULL)
428 /* This one was allocated by nslexer. You'll just
431 free((void *)((*src)[i].name));
439 * NSS module management.
441 /* The built-in NSS modules are all loaded at once. */
442 #define NSS_BACKEND(name, reg) \
443 ns_mtab *reg(unsigned int *, nss_module_unregister_fn *);
444 #include "nss_backends.h"
448 nss_load_builtin_modules(void)
450 #define NSS_BACKEND(name, reg) nss_load_module(#name, reg);
451 #include "nss_backends.h"
456 /* Load a built-in or dynamically linked module. If the `reg_fn'
457 * argument is non-NULL, assume a built-in module and use reg_fn to
458 * register it. Otherwise, search for a dynamic NSS module.
461 nss_load_module(const char *source, nss_module_register_fn reg_fn)
465 nss_module_register_fn fn;
467 memset(&mod, 0, sizeof(mod));
468 mod.name = strdup(source);
469 if (mod.name == NULL) {
470 nss_log_simple(LOG_ERR, "memory allocation failure");
473 if (reg_fn != NULL) {
474 /* The placeholder is required, as a NULL handle
475 * represents an invalid module.
477 mod.handle = nss_builtin_handle;
479 } else if (!is_dynamic())
482 if (snprintf(buf, sizeof(buf), "nss_%s.so.%d", mod.name,
483 NSS_MODULE_INTERFACE_VERSION) >= (int)sizeof(buf))
485 mod.handle = dlopen(buf, RTLD_LOCAL|RTLD_LAZY);
486 if (mod.handle == NULL) {
488 /* This gets pretty annoying since the built-in
489 * sources aren't modules yet.
491 nss_log(LOG_DEBUG, "%s, %s", mod.name, dlerror());
495 fn = (nss_module_register_fn)dlfunc(mod.handle,
496 "nss_module_register");
498 (void)dlclose(mod.handle);
500 nss_log(LOG_ERR, "%s, %s", mod.name, dlerror());
504 mod.mtab = fn(mod.name, &mod.mtabsize, &mod.unregister);
505 if (mod.mtab == NULL || mod.mtabsize == 0) {
506 if (mod.handle != nss_builtin_handle)
507 (void)dlclose(mod.handle);
509 nss_log(LOG_ERR, "%s, registration failed", mod.name);
512 if (mod.mtabsize > 1)
513 qsort(mod.mtab, mod.mtabsize, sizeof(mod.mtab[0]),
516 _nsmod = vector_append(&mod, _nsmod, &_nsmodsize, sizeof(*_nsmod));
517 vector_sort(_nsmod, _nsmodsize, sizeof(*_nsmod), string_compare);
523 ns_mod_free(ns_mod *mod)
527 if (mod->handle == NULL)
529 if (mod->unregister != NULL)
530 mod->unregister(mod->mtab, mod->mtabsize);
531 if (mod->handle != nss_builtin_handle)
532 (void)dlclose(mod->handle);
545 isthreaded = __isthreaded;
547 (void)_pthread_rwlock_wrlock(&nss_lock);
548 VECTOR_FREE(_nsmap, &_nsmapsize, sizeof(*_nsmap),
549 (vector_free_elem)ns_dbt_free);
550 VECTOR_FREE(_nsmod, &_nsmodsize, sizeof(*_nsmod),
551 (vector_free_elem)ns_mod_free);
553 (void)_pthread_rwlock_unlock(&nss_lock);
559 * Finally, the actual implementation.
562 nss_method_lookup(const char *source, const char *database,
563 const char *method, const ns_dtab disp_tab[], void **mdata)
569 if (disp_tab != NULL)
570 for (i = 0; disp_tab[i].src != NULL; i++)
571 if (strcasecmp(source, disp_tab[i].src) == 0) {
572 *mdata = disp_tab[i].mdata;
573 return (disp_tab[i].method);
575 mod = vector_search(&source, _nsmod, _nsmodsize, sizeof(*_nsmod),
577 if (mod != NULL && mod->handle != NULL) {
578 key.database = database;
580 match = bsearch(&key, mod->mtab, mod->mtabsize,
581 sizeof(mod->mtab[0]), mtab_compare);
583 *mdata = match->mdata;
584 return (match->method);
588 nss_log(LOG_DEBUG, "%s, %s, %s, not found", source, database,
595 __weak_reference(_nsdispatch, nsdispatch);
598 _nsdispatch(void *retval, const ns_dtab disp_tab[], const char *database,
599 const char *method_name, const ns_src defaults[], ...)
603 const ns_src *srclist;
606 int isthreaded, serrno, i, result, srclistsize;
609 nss_cache_data cache_data;
610 nss_cache_data *cache_data_p;
614 isthreaded = __isthreaded;
617 result = _pthread_rwlock_rdlock(&nss_lock);
623 result = nss_configure();
628 dbt = vector_search(&database, _nsmap, _nsmapsize, sizeof(*_nsmap),
631 srclist = dbt->srclist;
632 srclistsize = dbt->srclistsize;
636 while (srclist[srclistsize].name != NULL)
644 for (i = 0; i < srclistsize; i++) {
645 result = NS_NOTFOUND;
646 method = nss_method_lookup(srclist[i].name, database,
647 method_name, disp_tab, &mdata);
649 if (method != NULL) {
651 if (strcmp(srclist[i].name, NSSRC_CACHE) == 0 &&
652 nss_cache_cycle_prevention_func == NULL) {
653 #ifdef NS_STRICT_LIBC_EID_CHECKING
654 if (issetugid() != 0)
659 memset(&cache_data, 0, sizeof(nss_cache_data));
660 cache_data.info = (nss_cache_info const *)mdata;
661 cache_data_p = &cache_data;
663 va_start(ap, defaults);
664 if (cache_data.info->id_func != NULL)
665 result = __nss_common_cache_read(retval,
667 else if (cache_data.info->marshal_func != NULL)
668 result = __nss_mp_cache_read(retval,
671 result = __nss_mp_cache_end(retval,
676 va_start(ap, defaults);
677 result = method(retval, mdata, ap);
680 #else /* NS_CACHING */
681 va_start(ap, defaults);
682 result = method(retval, mdata, ap);
684 #endif /* NS_CACHING */
686 if (result & (srclist[i].flags))
692 if (cache_data_p != NULL &&
693 (result & (NS_NOTFOUND | NS_SUCCESS)) && cache_flag == 0) {
694 va_start(ap, defaults);
695 if (result == NS_SUCCESS) {
696 if (cache_data.info->id_func != NULL)
697 __nss_common_cache_write(retval, cache_data_p,
699 else if (cache_data.info->marshal_func != NULL)
700 __nss_mp_cache_write(retval, cache_data_p, ap);
701 } else if (result == NS_NOTFOUND) {
702 if (cache_data.info->id_func == NULL) {
703 if (cache_data.info->marshal_func != NULL)
704 __nss_mp_cache_write_submit(retval,
707 __nss_common_cache_write_negative(cache_data_p);
711 #endif /* NS_CACHING */
714 (void)_pthread_rwlock_unlock(&nss_lock);