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 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 * 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 * 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 * 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 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 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 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 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 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 335 nss_configure(void) 336 { 337 static time_t confmod; 338 static int already_initialized = 0; 339 struct stat statbuf; 340 int result, isthreaded; 341 const char *path; 342 #ifdef NS_CACHING 343 void *handle; 344 #endif 345 346 result = 0; 347 isthreaded = __isthreaded; 348 #if defined(_NSS_DEBUG) && defined(_NSS_SHOOT_FOOT) 349 /* NOTE WELL: THIS IS A SECURITY HOLE. This must only be built 350 * for debugging purposes and MUST NEVER be used in production. 351 */ 352 path = getenv("NSSWITCH_CONF"); 353 if (path == NULL) 354 #endif 355 path = _PATH_NS_CONF; 356 #ifndef NS_REREAD_CONF 357 /* 358 * Define NS_REREAD_CONF to have nsswitch notice changes 359 * to nsswitch.conf(5) during runtime. This involves calling 360 * stat(2) every time, which can result in performance hit. 361 */ 362 if (already_initialized) 363 return (0); 364 already_initialized = 1; 365 #endif /* NS_REREAD_CONF */ 366 if (stat(path, &statbuf) != 0) 367 return (0); 368 if (statbuf.st_mtime <= confmod) 369 return (0); 370 if (isthreaded) { 371 (void)_pthread_rwlock_unlock(&nss_lock); 372 result = _pthread_rwlock_wrlock(&nss_lock); 373 if (result != 0) 374 return (result); 375 if (stat(path, &statbuf) != 0) 376 goto fin; 377 if (statbuf.st_mtime <= confmod) 378 goto fin; 379 } 380 _nsyyin = fopen(path, "re"); 381 if (_nsyyin == NULL) 382 goto fin; 383 VECTOR_FREE(_nsmap, &_nsmapsize, sizeof(*_nsmap), 384 (vector_free_elem)ns_dbt_free); 385 VECTOR_FREE(_nsmod, &_nsmodsize, sizeof(*_nsmod), 386 (vector_free_elem)ns_mod_free); 387 if (confmod == 0) 388 (void)atexit(nss_atexit); 389 nss_load_builtin_modules(); 390 _nsyyparse(); 391 (void)fclose(_nsyyin); 392 vector_sort(_nsmap, _nsmapsize, sizeof(*_nsmap), string_compare); 393 confmod = statbuf.st_mtime; 394 395 #ifdef NS_CACHING 396 handle = libc_dlopen(NULL, RTLD_LAZY | RTLD_GLOBAL); 397 if (handle != NULL) { 398 nss_cache_cycle_prevention_func = dlsym(handle, 399 "_nss_cache_cycle_prevention_function"); 400 dlclose(handle); 401 } 402 #endif 403 fin: 404 if (isthreaded) { 405 (void)_pthread_rwlock_unlock(&nss_lock); 406 if (result == 0) 407 result = _pthread_rwlock_rdlock(&nss_lock); 408 } 409 return (result); 410 } 411 412 413 void 414 _nsdbtput(const ns_dbt *dbt) 415 { 416 unsigned int i; 417 ns_dbt *p; 418 419 for (i = 0; i < _nsmapsize; i++) { 420 p = vector_ref(i, _nsmap, _nsmapsize, sizeof(*_nsmap)); 421 if (string_compare(&dbt->name, &p->name) == 0) { 422 /* overwrite existing entry */ 423 if (p->srclist != NULL) 424 ns_src_free(&p->srclist, p->srclistsize); 425 memmove(p, dbt, sizeof(*dbt)); 426 return; 427 } 428 } 429 _nsmap = vector_append(dbt, _nsmap, &_nsmapsize, sizeof(*_nsmap)); 430 } 431 432 433 static void 434 ns_dbt_free(ns_dbt *dbt) 435 { 436 ns_src_free(&dbt->srclist, dbt->srclistsize); 437 if (dbt->name) 438 free((void *)dbt->name); 439 } 440 441 442 static void 443 ns_src_free(ns_src **src, int srclistsize) 444 { 445 int i; 446 447 for (i = 0; i < srclistsize; i++) 448 if ((*src)[i].name != NULL) 449 /* This one was allocated by nslexer. You'll just 450 * have to trust me. 451 */ 452 free((void *)((*src)[i].name)); 453 free(*src); 454 *src = NULL; 455 } 456 457 458 459 /* 460 * NSS module management. 461 */ 462 /* The built-in NSS modules are all loaded at once. */ 463 #define NSS_BACKEND(name, reg) \ 464 ns_mtab *reg(unsigned int *, nss_module_unregister_fn *); 465 #include "nss_backends.h" 466 #undef NSS_BACKEND 467 468 static void 469 nss_load_builtin_modules(void) 470 { 471 #define NSS_BACKEND(name, reg) nss_load_module(#name, reg); 472 #include "nss_backends.h" 473 #undef NSS_BACKEND 474 } 475 476 477 /* Load a built-in or dynamically linked module. If the `reg_fn' 478 * argument is non-NULL, assume a built-in module and use reg_fn to 479 * register it. Otherwise, search for a dynamic NSS module. 480 */ 481 static void 482 nss_load_module(const char *source, nss_module_register_fn reg_fn) 483 { 484 char buf[PATH_MAX]; 485 ns_mod mod; 486 nss_module_register_fn fn; 487 488 memset(&mod, 0, sizeof(mod)); 489 mod.name = strdup(source); 490 if (mod.name == NULL) { 491 nss_log_simple(LOG_ERR, "memory allocation failure"); 492 return; 493 } 494 if (reg_fn != NULL) { 495 /* The placeholder is required, as a NULL handle 496 * represents an invalid module. 497 */ 498 mod.handle = nss_builtin_handle; 499 fn = reg_fn; 500 } else if (!is_dynamic()) { 501 goto fin; 502 } else if (strcmp(source, NSSRC_CACHE) == 0 || 503 strcmp(source, NSSRC_COMPAT) == 0 || 504 strcmp(source, NSSRC_DB) == 0 || 505 strcmp(source, NSSRC_DNS) == 0 || 506 strcmp(source, NSSRC_FILES) == 0 || 507 strcmp(source, NSSRC_NIS) == 0) { 508 /* 509 * Avoid calling dlopen(3) for built-in modules. 510 */ 511 goto fin; 512 } else { 513 if (snprintf(buf, sizeof(buf), "nss_%s.so.%d", mod.name, 514 NSS_MODULE_INTERFACE_VERSION) >= (int)sizeof(buf)) 515 goto fin; 516 mod.handle = libc_dlopen(buf, RTLD_LOCAL|RTLD_LAZY); 517 if (mod.handle == NULL) { 518 #ifdef _NSS_DEBUG 519 /* This gets pretty annoying since the built-in 520 * sources aren't modules yet. 521 */ 522 nss_log(LOG_DEBUG, "%s, %s", mod.name, dlerror()); 523 #endif 524 goto fin; 525 } 526 fn = (nss_module_register_fn)dlfunc(mod.handle, 527 "nss_module_register"); 528 if (fn == NULL) { 529 (void)dlclose(mod.handle); 530 mod.handle = NULL; 531 nss_log(LOG_ERR, "%s, %s", mod.name, dlerror()); 532 goto fin; 533 } 534 } 535 mod.mtab = fn(mod.name, &mod.mtabsize, &mod.unregister); 536 if (mod.mtab == NULL || mod.mtabsize == 0) { 537 if (mod.handle != nss_builtin_handle) 538 (void)dlclose(mod.handle); 539 mod.handle = NULL; 540 nss_log(LOG_ERR, "%s, registration failed", mod.name); 541 goto fin; 542 } 543 if (mod.mtabsize > 1) 544 qsort(mod.mtab, mod.mtabsize, sizeof(mod.mtab[0]), 545 mtab_compare); 546 fin: 547 _nsmod = vector_append(&mod, _nsmod, &_nsmodsize, sizeof(*_nsmod)); 548 vector_sort(_nsmod, _nsmodsize, sizeof(*_nsmod), string_compare); 549 } 550 551 static int exiting = 0; 552 553 static void 554 ns_mod_free(ns_mod *mod) 555 { 556 557 free(mod->name); 558 if (mod->handle == NULL) 559 return; 560 if (mod->unregister != NULL) 561 mod->unregister(mod->mtab, mod->mtabsize); 562 if (mod->handle != nss_builtin_handle && !exiting) 563 (void)dlclose(mod->handle); 564 } 565 566 /* 567 * Cleanup 568 */ 569 static void 570 nss_atexit(void) 571 { 572 int isthreaded; 573 574 exiting = 1; 575 isthreaded = __isthreaded; 576 if (isthreaded) 577 (void)_pthread_rwlock_wrlock(&nss_lock); 578 VECTOR_FREE(_nsmap, &_nsmapsize, sizeof(*_nsmap), 579 (vector_free_elem)ns_dbt_free); 580 VECTOR_FREE(_nsmod, &_nsmodsize, sizeof(*_nsmod), 581 (vector_free_elem)ns_mod_free); 582 if (isthreaded) 583 (void)_pthread_rwlock_unlock(&nss_lock); 584 } 585 586 /* 587 * Finally, the actual implementation. 588 */ 589 static nss_method 590 nss_method_lookup(const char *source, const char *database, 591 const char *method, const ns_dtab disp_tab[], void **mdata) 592 { 593 ns_mod *mod; 594 ns_mtab *match, key; 595 int i; 596 597 if (disp_tab != NULL) 598 for (i = 0; disp_tab[i].src != NULL; i++) 599 if (strcasecmp(source, disp_tab[i].src) == 0) { 600 *mdata = disp_tab[i].mdata; 601 return (disp_tab[i].method); 602 } 603 mod = vector_search(&source, _nsmod, _nsmodsize, sizeof(*_nsmod), 604 string_compare); 605 if (mod != NULL && mod->handle != NULL) { 606 key.database = database; 607 key.name = method; 608 match = bsearch(&key, mod->mtab, mod->mtabsize, 609 sizeof(mod->mtab[0]), mtab_compare); 610 if (match != NULL) { 611 *mdata = match->mdata; 612 return (match->method); 613 } 614 } 615 616 *mdata = NULL; 617 return (NULL); 618 } 619 620 static void 621 fb_endstate(void *p) 622 { 623 free(p); 624 } 625 626 __weak_reference(_nsdispatch, nsdispatch); 627 628 int 629 _nsdispatch(void *retval, const ns_dtab disp_tab[], const char *database, 630 const char *method_name, const ns_src defaults[], ...) 631 { 632 va_list ap; 633 const ns_dbt *dbt; 634 const ns_src *srclist; 635 nss_method method, fb_method; 636 void *mdata; 637 int isthreaded, serrno, i, result, srclistsize; 638 struct fb_state *st; 639 int saved_depth; 640 641 #ifdef NS_CACHING 642 nss_cache_data cache_data; 643 nss_cache_data *cache_data_p; 644 int cache_flag; 645 #endif 646 647 dbt = NULL; 648 fb_method = NULL; 649 650 isthreaded = __isthreaded; 651 serrno = errno; 652 if (isthreaded) { 653 result = _pthread_rwlock_rdlock(&nss_lock); 654 if (result != 0) { 655 result = NS_UNAVAIL; 656 goto fin; 657 } 658 } 659 660 result = fb_getstate(&st); 661 if (result != 0) { 662 result = NS_UNAVAIL; 663 goto fin; 664 } 665 666 result = nss_configure(); 667 if (result != 0) { 668 result = NS_UNAVAIL; 669 goto fin; 670 } 671 ++st->dispatch_depth; 672 if (st->dispatch_depth > st->fallback_depth) { 673 dbt = vector_search(&database, _nsmap, _nsmapsize, sizeof(*_nsmap), 674 string_compare); 675 fb_method = nss_method_lookup(NSSRC_FALLBACK, database, 676 method_name, disp_tab, &mdata); 677 } 678 679 if (dbt != NULL) { 680 srclist = dbt->srclist; 681 srclistsize = dbt->srclistsize; 682 } else { 683 srclist = defaults; 684 srclistsize = 0; 685 while (srclist[srclistsize].name != NULL) 686 srclistsize++; 687 } 688 689 #ifdef NS_CACHING 690 cache_data_p = NULL; 691 cache_flag = 0; 692 #endif 693 for (i = 0; i < srclistsize; i++) { 694 result = NS_NOTFOUND; 695 method = nss_method_lookup(srclist[i].name, database, 696 method_name, disp_tab, &mdata); 697 698 if (method != NULL) { 699 #ifdef NS_CACHING 700 if (strcmp(srclist[i].name, NSSRC_CACHE) == 0 && 701 nss_cache_cycle_prevention_func == NULL) { 702 #ifdef NS_STRICT_LIBC_EID_CHECKING 703 if (issetugid() != 0) 704 continue; 705 #endif 706 cache_flag = 1; 707 708 memset(&cache_data, 0, sizeof(nss_cache_data)); 709 cache_data.info = (nss_cache_info const *)mdata; 710 cache_data_p = &cache_data; 711 712 va_start(ap, defaults); 713 if (cache_data.info->id_func != NULL) 714 result = __nss_common_cache_read(retval, 715 cache_data_p, ap); 716 else if (cache_data.info->marshal_func != NULL) 717 result = __nss_mp_cache_read(retval, 718 cache_data_p, ap); 719 else 720 result = __nss_mp_cache_end(retval, 721 cache_data_p, ap); 722 va_end(ap); 723 } else { 724 cache_flag = 0; 725 errno = 0; 726 va_start(ap, defaults); 727 result = method(retval, mdata, ap); 728 va_end(ap); 729 } 730 #else /* NS_CACHING */ 731 errno = 0; 732 va_start(ap, defaults); 733 result = method(retval, mdata, ap); 734 va_end(ap); 735 #endif /* NS_CACHING */ 736 737 if (result & (srclist[i].flags)) 738 break; 739 } else { 740 if (fb_method != NULL) { 741 saved_depth = st->fallback_depth; 742 st->fallback_depth = st->dispatch_depth + 1; 743 va_start(ap, defaults); 744 result = fb_method(retval, 745 (void *)srclist[i].name, ap); 746 va_end(ap); 747 st->fallback_depth = saved_depth; 748 } else 749 nss_log(LOG_DEBUG, "%s, %s, %s, not found, " 750 "and no fallback provided", 751 srclist[i].name, database, method_name); 752 } 753 } 754 755 #ifdef NS_CACHING 756 if (cache_data_p != NULL && 757 (result & (NS_NOTFOUND | NS_SUCCESS)) && cache_flag == 0) { 758 va_start(ap, defaults); 759 if (result == NS_SUCCESS) { 760 if (cache_data.info->id_func != NULL) 761 __nss_common_cache_write(retval, cache_data_p, 762 ap); 763 else if (cache_data.info->marshal_func != NULL) 764 __nss_mp_cache_write(retval, cache_data_p, ap); 765 } else if (result == NS_NOTFOUND) { 766 if (cache_data.info->id_func == NULL) { 767 if (cache_data.info->marshal_func != NULL) 768 __nss_mp_cache_write_submit(retval, 769 cache_data_p, ap); 770 } else 771 __nss_common_cache_write_negative(cache_data_p); 772 } 773 va_end(ap); 774 } 775 #endif /* NS_CACHING */ 776 777 if (isthreaded) 778 (void)_pthread_rwlock_unlock(&nss_lock); 779 --st->dispatch_depth; 780 fin: 781 errno = serrno; 782 return (result); 783 } 784