nsdispatch.c revision 1.38 1 1.38 christos /* $NetBSD: nsdispatch.c,v 1.38 2014/09/18 13:58:20 christos Exp $ */
2 1.2 lukem
3 1.2 lukem /*-
4 1.22 thorpej * Copyright (c) 1997, 1998, 1999, 2004 The NetBSD Foundation, Inc.
5 1.2 lukem * All rights reserved.
6 1.2 lukem *
7 1.2 lukem * This code is derived from software contributed to The NetBSD Foundation
8 1.22 thorpej * by Luke Mewburn; and by Jason R. Thorpe.
9 1.2 lukem *
10 1.2 lukem * Redistribution and use in source and binary forms, with or without
11 1.2 lukem * modification, are permitted provided that the following conditions
12 1.2 lukem * are met:
13 1.2 lukem * 1. Redistributions of source code must retain the above copyright
14 1.2 lukem * notice, this list of conditions and the following disclaimer.
15 1.2 lukem * 2. Redistributions in binary form must reproduce the above copyright
16 1.2 lukem * notice, this list of conditions and the following disclaimer in the
17 1.2 lukem * documentation and/or other materials provided with the distribution.
18 1.2 lukem *
19 1.2 lukem * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 1.2 lukem * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 1.2 lukem * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 1.2 lukem * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 1.2 lukem * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 1.2 lukem * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 1.2 lukem * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 1.2 lukem * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 1.2 lukem * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 1.2 lukem * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 1.2 lukem * POSSIBILITY OF SUCH DAMAGE.
30 1.2 lukem */
31 1.9 lukem
32 1.22 thorpej /*-
33 1.22 thorpej * Copyright (c) 2003 Networks Associates Technology, Inc.
34 1.22 thorpej * All rights reserved.
35 1.22 thorpej *
36 1.22 thorpej * Portions of this software were developed for the FreeBSD Project by
37 1.22 thorpej * Jacques A. Vidrine, Safeport Network Services, and Network
38 1.22 thorpej * Associates Laboratories, the Security Research Division of Network
39 1.22 thorpej * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035
40 1.22 thorpej * ("CBOSS"), as part of the DARPA CHATS research program.
41 1.22 thorpej *
42 1.22 thorpej * Redistribution and use in source and binary forms, with or without
43 1.22 thorpej * modification, are permitted provided that the following conditions
44 1.22 thorpej * are met:
45 1.22 thorpej * 1. Redistributions of source code must retain the above copyright
46 1.22 thorpej * notice, this list of conditions and the following disclaimer.
47 1.22 thorpej * 2. Redistributions in binary form must reproduce the above copyright
48 1.22 thorpej * notice, this list of conditions and the following disclaimer in the
49 1.22 thorpej * documentation and/or other materials provided with the distribution.
50 1.22 thorpej *
51 1.22 thorpej * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
52 1.22 thorpej * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
53 1.22 thorpej * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
54 1.22 thorpej * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
55 1.22 thorpej * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
56 1.22 thorpej * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
57 1.22 thorpej * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
58 1.22 thorpej * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
59 1.22 thorpej * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
60 1.22 thorpej * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
61 1.22 thorpej * SUCH DAMAGE.
62 1.22 thorpej */
63 1.22 thorpej
64 1.9 lukem #include <sys/cdefs.h>
65 1.9 lukem #if defined(LIBC_SCCS) && !defined(lint)
66 1.38 christos __RCSID("$NetBSD: nsdispatch.c,v 1.38 2014/09/18 13:58:20 christos Exp $");
67 1.9 lukem #endif /* LIBC_SCCS and not lint */
68 1.2 lukem
69 1.6 lukem #include "namespace.h"
70 1.6 lukem
71 1.2 lukem #include <sys/types.h>
72 1.2 lukem #include <sys/param.h>
73 1.2 lukem #include <sys/stat.h>
74 1.23 thorpej #include <sys/queue.h>
75 1.2 lukem
76 1.12 lukem #include <assert.h>
77 1.22 thorpej #ifdef __ELF__
78 1.22 thorpej #include <dlfcn.h>
79 1.22 thorpej #endif /* __ELF__ */
80 1.2 lukem #include <err.h>
81 1.2 lukem #include <fcntl.h>
82 1.2 lukem #define _NS_PRIVATE
83 1.2 lukem #include <nsswitch.h>
84 1.18 wiz #include <stdarg.h>
85 1.2 lukem #include <stdio.h>
86 1.2 lukem #include <stdlib.h>
87 1.2 lukem #include <string.h>
88 1.2 lukem #include <unistd.h>
89 1.22 thorpej
90 1.22 thorpej #include "reentrant.h"
91 1.10 lukem
92 1.17 christos extern FILE *_nsyyin;
93 1.21 thorpej extern int _nsyyparse(void);
94 1.17 christos
95 1.17 christos
96 1.6 lukem #ifdef __weak_alias
97 1.16 mycroft __weak_alias(nsdispatch,_nsdispatch)
98 1.6 lukem #endif
99 1.2 lukem
100 1.2 lukem
101 1.5 lukem /*
102 1.5 lukem * default sourcelist: `files'
103 1.5 lukem */
104 1.5 lukem const ns_src __nsdefaultsrc[] = {
105 1.28 lukem { NSSRC_FILES, NS_SUCCESS },
106 1.31 christos { 0, 0 },
107 1.5 lukem };
108 1.5 lukem
109 1.28 lukem const ns_src __nsdefaultcompat[] = {
110 1.28 lukem { NSSRC_COMPAT, NS_SUCCESS },
111 1.31 christos { 0, 0 }
112 1.28 lukem };
113 1.28 lukem
114 1.28 lukem const ns_src __nsdefaultcompat_forceall[] = {
115 1.28 lukem { NSSRC_COMPAT, NS_SUCCESS | NS_FORCEALL },
116 1.31 christos { 0, 0 }
117 1.28 lukem };
118 1.28 lukem
119 1.28 lukem const ns_src __nsdefaultfiles[] = {
120 1.28 lukem { NSSRC_FILES, NS_SUCCESS },
121 1.31 christos { 0, 0 },
122 1.28 lukem };
123 1.28 lukem
124 1.28 lukem const ns_src __nsdefaultfiles_forceall[] = {
125 1.28 lukem { NSSRC_FILES, NS_SUCCESS | NS_FORCEALL },
126 1.31 christos { 0, 0 },
127 1.28 lukem };
128 1.28 lukem
129 1.28 lukem const ns_src __nsdefaultnis[] = {
130 1.28 lukem { NSSRC_NIS, NS_SUCCESS },
131 1.31 christos { 0, 0 }
132 1.28 lukem };
133 1.28 lukem
134 1.28 lukem const ns_src __nsdefaultnis_forceall[] = {
135 1.28 lukem { NSSRC_NIS, NS_SUCCESS | NS_FORCEALL },
136 1.31 christos { 0, 0 }
137 1.28 lukem };
138 1.28 lukem
139 1.28 lukem
140 1.22 thorpej /* Database, source mappings. */
141 1.22 thorpej static u_int _nsmapsize;
142 1.22 thorpej static ns_dbt *_nsmap;
143 1.22 thorpej
144 1.22 thorpej /* Nsswitch modules. */
145 1.22 thorpej static u_int _nsmodsize;
146 1.22 thorpej static ns_mod *_nsmod;
147 1.22 thorpej
148 1.22 thorpej /* Placeholder for built-in modules' dlopen() handles. */
149 1.22 thorpej static void *_nsbuiltin = &_nsbuiltin;
150 1.5 lukem
151 1.19 christos #ifdef _REENTRANT
152 1.22 thorpej /*
153 1.22 thorpej * Global nsswitch data structures are mostly read-only, but we update them
154 1.22 thorpej * when we read or re-read nsswitch.conf.
155 1.22 thorpej */
156 1.22 thorpej static rwlock_t _nslock = RWLOCK_INITIALIZER;
157 1.23 thorpej
158 1.23 thorpej /*
159 1.23 thorpej * List of threads currently in nsdispatch(). We use this to detect
160 1.23 thorpej * recursive calls and avoid reloading configuration in such cases,
161 1.23 thorpej * which could cause deadlock.
162 1.23 thorpej */
163 1.23 thorpej struct _ns_drec {
164 1.23 thorpej LIST_ENTRY(_ns_drec) list;
165 1.23 thorpej thr_t thr;
166 1.23 thorpej };
167 1.23 thorpej static LIST_HEAD(, _ns_drec) _ns_drec = LIST_HEAD_INITIALIZER(&_ns_drec);
168 1.23 thorpej static mutex_t _ns_drec_lock = MUTEX_INITIALIZER;
169 1.23 thorpej #endif /* _REENTRANT */
170 1.22 thorpej
171 1.22 thorpej
172 1.22 thorpej /*
173 1.22 thorpej * Runtime determination of whether we are dynamically linked or not.
174 1.22 thorpej */
175 1.35 joerg #ifndef __ELF__
176 1.35 joerg #define is_dynamic() (0) /* don't bother - switch to ELF! */
177 1.36 joerg #else
178 1.36 joerg __weakref_visible int rtld_DYNAMIC __weak_reference(_DYNAMIC);
179 1.35 joerg #define is_dynamic() (&rtld_DYNAMIC != NULL)
180 1.35 joerg #endif
181 1.19 christos
182 1.2 lukem
183 1.2 lukem /*
184 1.22 thorpej * size of dynamic array chunk for _nsmap and _nsmap[x].srclist (and other
185 1.22 thorpej * growing arrays).
186 1.2 lukem */
187 1.2 lukem #define NSELEMSPERCHUNK 8
188 1.2 lukem
189 1.22 thorpej /*
190 1.22 thorpej * Dynamically growable arrays are used for lists of databases, sources,
191 1.22 thorpej * and modules. The following "vector" API is used to isolate the
192 1.22 thorpej * common operations.
193 1.22 thorpej */
194 1.22 thorpej typedef void (*_nsvect_free_elem)(void *);
195 1.22 thorpej
196 1.22 thorpej static void *
197 1.22 thorpej _nsvect_append(const void *elem, void *vec, u_int *count, size_t esize)
198 1.22 thorpej {
199 1.22 thorpej void *p;
200 1.22 thorpej
201 1.22 thorpej if ((*count % NSELEMSPERCHUNK) == 0) {
202 1.22 thorpej p = realloc(vec, (*count + NSELEMSPERCHUNK) * esize);
203 1.22 thorpej if (p == NULL)
204 1.22 thorpej return (NULL);
205 1.22 thorpej vec = p;
206 1.22 thorpej }
207 1.22 thorpej memmove((void *)(((uintptr_t)vec) + (*count * esize)), elem, esize);
208 1.22 thorpej (*count)++;
209 1.22 thorpej return (vec);
210 1.22 thorpej }
211 1.22 thorpej
212 1.22 thorpej static void *
213 1.22 thorpej _nsvect_elem(u_int i, void *vec, u_int count, size_t esize)
214 1.22 thorpej {
215 1.22 thorpej
216 1.22 thorpej if (i < count)
217 1.22 thorpej return ((void *)((uintptr_t)vec + (i * esize)));
218 1.22 thorpej else
219 1.22 thorpej return (NULL);
220 1.22 thorpej }
221 1.22 thorpej
222 1.22 thorpej static void
223 1.22 thorpej _nsvect_free(void *vec, u_int *count, size_t esize, _nsvect_free_elem free_elem)
224 1.22 thorpej {
225 1.22 thorpej void *elem;
226 1.22 thorpej u_int i;
227 1.22 thorpej
228 1.22 thorpej for (i = 0; i < *count; i++) {
229 1.22 thorpej elem = _nsvect_elem(i, vec, *count, esize);
230 1.22 thorpej if (elem != NULL)
231 1.22 thorpej (*free_elem)(elem);
232 1.22 thorpej }
233 1.22 thorpej if (vec != NULL)
234 1.22 thorpej free(vec);
235 1.22 thorpej *count = 0;
236 1.22 thorpej }
237 1.22 thorpej #define _NSVECT_FREE(v, c, s, f) \
238 1.22 thorpej do { \
239 1.22 thorpej _nsvect_free((v), (c), (s), (f)); \
240 1.22 thorpej (v) = NULL; \
241 1.22 thorpej } while (/*CONSTCOND*/0)
242 1.2 lukem
243 1.21 thorpej static int
244 1.22 thorpej _nsdbtcmp(const void *a, const void *b)
245 1.2 lukem {
246 1.22 thorpej
247 1.7 christos return (strcasecmp(((const ns_dbt *)a)->name,
248 1.7 christos ((const ns_dbt *)b)->name));
249 1.2 lukem }
250 1.2 lukem
251 1.22 thorpej static int
252 1.22 thorpej _nsmodcmp(const void *a, const void *b)
253 1.22 thorpej {
254 1.22 thorpej
255 1.22 thorpej return (strcasecmp(((const ns_mod *)a)->name,
256 1.22 thorpej ((const ns_mod *)b)->name));
257 1.22 thorpej }
258 1.22 thorpej
259 1.22 thorpej static int
260 1.22 thorpej _nsmtabcmp(const void *a, const void *b)
261 1.22 thorpej {
262 1.22 thorpej int cmp;
263 1.22 thorpej
264 1.22 thorpej cmp = strcmp(((const ns_mtab *)a)->name,
265 1.22 thorpej ((const ns_mtab *)b)->name);
266 1.22 thorpej if (cmp)
267 1.22 thorpej return (cmp);
268 1.22 thorpej
269 1.22 thorpej return (strcasecmp(((const ns_mtab *)a)->database,
270 1.22 thorpej ((const ns_mtab *)b)->database));
271 1.22 thorpej }
272 1.22 thorpej
273 1.22 thorpej static void
274 1.22 thorpej _nsmodfree(ns_mod *mod)
275 1.22 thorpej {
276 1.22 thorpej
277 1.30 christos free(__UNCONST(mod->name));
278 1.22 thorpej if (mod->handle == NULL)
279 1.22 thorpej return;
280 1.22 thorpej if (mod->unregister != NULL)
281 1.22 thorpej (*mod->unregister)(mod->mtab, mod->mtabsize);
282 1.22 thorpej #ifdef __ELF__
283 1.22 thorpej if (mod->handle != _nsbuiltin)
284 1.22 thorpej (void) dlclose(mod->handle);
285 1.22 thorpej #endif /* __ELF__ */
286 1.22 thorpej }
287 1.22 thorpej
288 1.22 thorpej /*
289 1.22 thorpej * Load a built-in or dyanamically linked module. If the `reg_fn'
290 1.22 thorpej * argument is non-NULL, assume a built-in module and use `reg_fn'
291 1.22 thorpej * to register it. Otherwise, search for a dynamic nsswitch module.
292 1.22 thorpej */
293 1.22 thorpej static int
294 1.22 thorpej _nsloadmod(const char *source, nss_module_register_fn reg_fn)
295 1.22 thorpej {
296 1.24 simonb #ifdef __ELF__
297 1.22 thorpej char buf[PATH_MAX];
298 1.24 simonb #endif
299 1.22 thorpej ns_mod mod, *new;
300 1.22 thorpej
301 1.22 thorpej memset(&mod, 0, sizeof(mod));
302 1.22 thorpej mod.name = strdup(source);
303 1.22 thorpej if (mod.name == NULL)
304 1.22 thorpej return (-1);
305 1.22 thorpej
306 1.22 thorpej if (reg_fn != NULL) {
307 1.22 thorpej /*
308 1.22 thorpej * The placeholder is required, as a NULL handle
309 1.22 thorpej * represents an invalid module.
310 1.22 thorpej */
311 1.22 thorpej mod.handle = _nsbuiltin;
312 1.22 thorpej } else if (!is_dynamic()) {
313 1.22 thorpej goto out;
314 1.22 thorpej } else {
315 1.22 thorpej #ifdef __ELF__
316 1.22 thorpej if (snprintf(buf, sizeof(buf), "nss_%s.so.%d", mod.name,
317 1.22 thorpej NSS_MODULE_INTERFACE_VERSION) >= (int)sizeof(buf))
318 1.22 thorpej goto out;
319 1.22 thorpej mod.handle = dlopen(buf, RTLD_LOCAL | RTLD_LAZY);
320 1.22 thorpej if (mod.handle == NULL) {
321 1.22 thorpej #ifdef _NSS_DEBUG
322 1.22 thorpej /*
323 1.22 thorpej * This gets pretty annoying, since the built-in
324 1.22 thorpej * sources are not yet modules.
325 1.22 thorpej */
326 1.22 thorpej /* XXX log some error? */
327 1.22 thorpej #endif
328 1.22 thorpej goto out;
329 1.22 thorpej }
330 1.22 thorpej reg_fn = (nss_module_register_fn) dlsym(mod.handle,
331 1.22 thorpej "nss_module_register");
332 1.22 thorpej if (reg_fn == NULL) {
333 1.22 thorpej (void) dlclose(mod.handle);
334 1.22 thorpej mod.handle = NULL;
335 1.22 thorpej /* XXX log some error? */
336 1.22 thorpej goto out;
337 1.22 thorpej }
338 1.22 thorpej #else /* ! __ELF__ */
339 1.22 thorpej mod.handle = NULL;
340 1.22 thorpej #endif /* __ELF__ */
341 1.22 thorpej }
342 1.22 thorpej mod.mtab = (*reg_fn)(mod.name, &mod.mtabsize, &mod.unregister);
343 1.22 thorpej if (mod.mtab == NULL || mod.mtabsize == 0) {
344 1.22 thorpej #ifdef __ELF__
345 1.22 thorpej if (mod.handle != _nsbuiltin)
346 1.22 thorpej (void) dlclose(mod.handle);
347 1.22 thorpej #endif /* __ELF__ */
348 1.22 thorpej mod.handle = NULL;
349 1.22 thorpej /* XXX log some error? */
350 1.22 thorpej goto out;
351 1.22 thorpej }
352 1.22 thorpej if (mod.mtabsize > 1)
353 1.22 thorpej qsort(mod.mtab, mod.mtabsize, sizeof(mod.mtab[0]),
354 1.22 thorpej _nsmtabcmp);
355 1.22 thorpej out:
356 1.22 thorpej new = _nsvect_append(&mod, _nsmod, &_nsmodsize, sizeof(*_nsmod));
357 1.22 thorpej if (new == NULL) {
358 1.22 thorpej _nsmodfree(&mod);
359 1.22 thorpej return (-1);
360 1.22 thorpej }
361 1.22 thorpej _nsmod = new;
362 1.22 thorpej /* _nsmodsize already incremented */
363 1.22 thorpej
364 1.22 thorpej qsort(_nsmod, _nsmodsize, sizeof(*_nsmod), _nsmodcmp);
365 1.22 thorpej return (0);
366 1.22 thorpej }
367 1.22 thorpej
368 1.22 thorpej static void
369 1.22 thorpej _nsloadbuiltin(void)
370 1.22 thorpej {
371 1.22 thorpej
372 1.22 thorpej /* Do nothing, for now. */
373 1.22 thorpej }
374 1.2 lukem
375 1.15 lukem int
376 1.21 thorpej _nsdbtaddsrc(ns_dbt *dbt, const ns_src *src)
377 1.2 lukem {
378 1.22 thorpej void *new;
379 1.22 thorpej const ns_mod *mod;
380 1.22 thorpej ns_mod modkey;
381 1.12 lukem
382 1.12 lukem _DIAGASSERT(dbt != NULL);
383 1.12 lukem _DIAGASSERT(src != NULL);
384 1.12 lukem
385 1.22 thorpej new = _nsvect_append(src, dbt->srclist, &dbt->srclistsize,
386 1.22 thorpej sizeof(*src));
387 1.22 thorpej if (new == NULL)
388 1.22 thorpej return (-1);
389 1.22 thorpej dbt->srclist = new;
390 1.22 thorpej /* dbt->srclistsize already incremented */
391 1.22 thorpej
392 1.22 thorpej modkey.name = src->name;
393 1.37 christos mod = bsearch(&modkey, _nsmod, _nsmodsize, sizeof(*_nsmod), _nsmodcmp);
394 1.22 thorpej if (mod == NULL)
395 1.22 thorpej return (_nsloadmod(src->name, NULL));
396 1.15 lukem
397 1.15 lukem return (0);
398 1.2 lukem }
399 1.2 lukem
400 1.2 lukem void
401 1.21 thorpej _nsdbtdump(const ns_dbt *dbt)
402 1.2 lukem {
403 1.34 lukem unsigned int i;
404 1.2 lukem
405 1.12 lukem _DIAGASSERT(dbt != NULL);
406 1.12 lukem
407 1.2 lukem printf("%s (%d source%s):", dbt->name, dbt->srclistsize,
408 1.2 lukem dbt->srclistsize == 1 ? "" : "s");
409 1.2 lukem for (i = 0; i < dbt->srclistsize; i++) {
410 1.2 lukem printf(" %s", dbt->srclist[i].name);
411 1.2 lukem if (!(dbt->srclist[i].flags &
412 1.2 lukem (NS_UNAVAIL|NS_NOTFOUND|NS_TRYAGAIN)) &&
413 1.2 lukem (dbt->srclist[i].flags & NS_SUCCESS))
414 1.2 lukem continue;
415 1.2 lukem printf(" [");
416 1.2 lukem if (!(dbt->srclist[i].flags & NS_SUCCESS))
417 1.2 lukem printf(" SUCCESS=continue");
418 1.2 lukem if (dbt->srclist[i].flags & NS_UNAVAIL)
419 1.2 lukem printf(" UNAVAIL=return");
420 1.2 lukem if (dbt->srclist[i].flags & NS_NOTFOUND)
421 1.2 lukem printf(" NOTFOUND=return");
422 1.2 lukem if (dbt->srclist[i].flags & NS_TRYAGAIN)
423 1.2 lukem printf(" TRYAGAIN=return");
424 1.2 lukem printf(" ]");
425 1.2 lukem }
426 1.2 lukem printf("\n");
427 1.2 lukem }
428 1.2 lukem
429 1.22 thorpej static void
430 1.22 thorpej _nssrclist_free(ns_src **src, u_int srclistsize)
431 1.2 lukem {
432 1.22 thorpej u_int i;
433 1.2 lukem
434 1.22 thorpej for (i = 0; i < srclistsize; i++) {
435 1.30 christos if ((*src)[i].name != NULL)
436 1.30 christos free(__UNCONST((*src)[i].name));
437 1.22 thorpej }
438 1.22 thorpej free(*src);
439 1.22 thorpej *src = NULL;
440 1.22 thorpej }
441 1.2 lukem
442 1.22 thorpej static void
443 1.22 thorpej _nsdbtfree(ns_dbt *dbt)
444 1.22 thorpej {
445 1.2 lukem
446 1.22 thorpej _nssrclist_free(&dbt->srclist, dbt->srclistsize);
447 1.30 christos if (dbt->name != NULL)
448 1.30 christos free(__UNCONST(dbt->name));
449 1.2 lukem }
450 1.2 lukem
451 1.15 lukem int
452 1.21 thorpej _nsdbtput(const ns_dbt *dbt)
453 1.2 lukem {
454 1.22 thorpej ns_dbt *p;
455 1.22 thorpej void *new;
456 1.22 thorpej u_int i;
457 1.2 lukem
458 1.12 lukem _DIAGASSERT(dbt != NULL);
459 1.12 lukem
460 1.2 lukem for (i = 0; i < _nsmapsize; i++) {
461 1.22 thorpej p = _nsvect_elem(i, _nsmap, _nsmapsize, sizeof(*_nsmap));
462 1.22 thorpej if (strcasecmp(dbt->name, p->name) == 0) {
463 1.2 lukem /* overwrite existing entry */
464 1.22 thorpej if (p->srclist != NULL)
465 1.22 thorpej _nssrclist_free(&p->srclist, p->srclistsize);
466 1.22 thorpej memmove(p, dbt, sizeof(*dbt));
467 1.15 lukem return (0);
468 1.2 lukem }
469 1.2 lukem }
470 1.22 thorpej new = _nsvect_append(dbt, _nsmap, &_nsmapsize, sizeof(*_nsmap));
471 1.22 thorpej if (new == NULL)
472 1.22 thorpej return (-1);
473 1.22 thorpej _nsmap = new;
474 1.22 thorpej /* _nsmapsize already incremented */
475 1.2 lukem
476 1.22 thorpej return (0);
477 1.22 thorpej }
478 1.22 thorpej
479 1.22 thorpej /*
480 1.22 thorpej * This function is called each time nsdispatch() is called. If this
481 1.22 thorpej * is the first call, or if the configuration has changed, (re-)prepare
482 1.22 thorpej * the global data used by NSS.
483 1.22 thorpej */
484 1.22 thorpej static int
485 1.22 thorpej _nsconfigure(void)
486 1.22 thorpej {
487 1.22 thorpej #ifdef _REENTRANT
488 1.22 thorpej static mutex_t _nsconflock = MUTEX_INITIALIZER;
489 1.22 thorpej #endif
490 1.22 thorpej static time_t _nsconfmod;
491 1.22 thorpej struct stat statbuf;
492 1.15 lukem
493 1.22 thorpej mutex_lock(&_nsconflock);
494 1.22 thorpej
495 1.22 thorpej if (stat(_PATH_NS_CONF, &statbuf) == -1) {
496 1.22 thorpej /*
497 1.22 thorpej * No nsswitch.conf; just use whatever configuration we
498 1.22 thorpej * currently have, or fall back on the defaults specified
499 1.22 thorpej * by the caller.
500 1.22 thorpej */
501 1.22 thorpej mutex_unlock(&_nsconflock);
502 1.22 thorpej return (0);
503 1.22 thorpej }
504 1.22 thorpej
505 1.22 thorpej if (statbuf.st_mtime <= _nsconfmod) {
506 1.22 thorpej /* Internal state is up-to-date with nsswitch.conf. */
507 1.22 thorpej mutex_unlock(&_nsconflock);
508 1.22 thorpej return (0);
509 1.22 thorpej }
510 1.22 thorpej
511 1.22 thorpej /*
512 1.22 thorpej * Ok, we've decided we need to update the nsswitch configuration
513 1.23 thorpej * structures. Acquire a write-lock on _nslock while continuing
514 1.23 thorpej * to hold _nsconflock. Acquiring a write-lock blocks while
515 1.23 thorpej * waiting for other threads already holding a read-lock to clear.
516 1.23 thorpej * We hold _nsconflock for the duration, and update the time stamp
517 1.23 thorpej * at the end of the update operation, at which time we release
518 1.23 thorpej * both locks.
519 1.22 thorpej */
520 1.22 thorpej rwlock_wrlock(&_nslock);
521 1.22 thorpej
522 1.38 christos _nsyyin = fopen(_PATH_NS_CONF, "re");
523 1.22 thorpej if (_nsyyin == NULL) {
524 1.22 thorpej /*
525 1.22 thorpej * Unable to open nsswitch.conf; behave as though the
526 1.22 thorpej * stat() above failed. Even though we have already
527 1.22 thorpej * updated _nsconfmod, if the file reappears, the
528 1.22 thorpej * mtime will change.
529 1.22 thorpej */
530 1.23 thorpej goto out;
531 1.2 lukem }
532 1.22 thorpej
533 1.22 thorpej _NSVECT_FREE(_nsmap, &_nsmapsize, sizeof(*_nsmap),
534 1.22 thorpej (_nsvect_free_elem) _nsdbtfree);
535 1.22 thorpej _NSVECT_FREE(_nsmod, &_nsmodsize, sizeof(*_nsmod),
536 1.22 thorpej (_nsvect_free_elem) _nsmodfree);
537 1.22 thorpej
538 1.22 thorpej _nsloadbuiltin();
539 1.22 thorpej
540 1.22 thorpej _nsyyparse();
541 1.22 thorpej (void) fclose(_nsyyin);
542 1.22 thorpej if (_nsmapsize != 0)
543 1.22 thorpej qsort(_nsmap, _nsmapsize, sizeof(*_nsmap), _nsdbtcmp);
544 1.23 thorpej
545 1.23 thorpej _nsconfmod = statbuf.st_mtime;
546 1.23 thorpej
547 1.23 thorpej out:
548 1.22 thorpej rwlock_unlock(&_nslock);
549 1.23 thorpej mutex_unlock(&_nsconflock);
550 1.15 lukem return (0);
551 1.2 lukem }
552 1.2 lukem
553 1.22 thorpej static nss_method
554 1.22 thorpej _nsmethod(const char *source, const char *database, const char *method,
555 1.22 thorpej const ns_dtab disp_tab[], void **cb_data)
556 1.22 thorpej {
557 1.22 thorpej int curdisp;
558 1.22 thorpej ns_mod *mod, modkey;
559 1.22 thorpej ns_mtab *mtab, mtabkey;
560 1.22 thorpej
561 1.22 thorpej if (disp_tab != NULL) {
562 1.22 thorpej for (curdisp = 0; disp_tab[curdisp].src != NULL; curdisp++) {
563 1.22 thorpej if (strcasecmp(source, disp_tab[curdisp].src) == 0) {
564 1.22 thorpej *cb_data = disp_tab[curdisp].cb_data;
565 1.22 thorpej return (disp_tab[curdisp].callback);
566 1.22 thorpej }
567 1.22 thorpej }
568 1.22 thorpej }
569 1.22 thorpej
570 1.22 thorpej modkey.name = source;
571 1.22 thorpej mod = bsearch(&modkey, _nsmod, _nsmodsize, sizeof(*_nsmod),
572 1.22 thorpej _nsmodcmp);
573 1.22 thorpej if (mod != NULL && mod->handle != NULL) {
574 1.22 thorpej mtabkey.database = database;
575 1.22 thorpej mtabkey.name = method;
576 1.22 thorpej mtab = bsearch(&mtabkey, mod->mtab, mod->mtabsize,
577 1.22 thorpej sizeof(mod->mtab[0]), _nsmtabcmp);
578 1.22 thorpej if (mtab != NULL) {
579 1.22 thorpej *cb_data = mtab->mdata;
580 1.22 thorpej return (mtab->method);
581 1.22 thorpej }
582 1.22 thorpej }
583 1.22 thorpej
584 1.22 thorpej *cb_data = NULL;
585 1.22 thorpej return (NULL);
586 1.22 thorpej }
587 1.2 lukem
588 1.2 lukem int
589 1.11 christos /*ARGSUSED*/
590 1.5 lukem nsdispatch(void *retval, const ns_dtab disp_tab[], const char *database,
591 1.5 lukem const char *method, const ns_src defaults[], ...)
592 1.2 lukem {
593 1.23 thorpej static int _nsdispatching;
594 1.23 thorpej #ifdef _REENTRANT
595 1.23 thorpej struct _ns_drec drec, *ldrec;
596 1.23 thorpej #endif
597 1.2 lukem va_list ap;
598 1.22 thorpej int i, result;
599 1.22 thorpej ns_dbt key;
600 1.2 lukem const ns_dbt *dbt;
601 1.5 lukem const ns_src *srclist;
602 1.5 lukem int srclistsize;
603 1.22 thorpej nss_method cb;
604 1.22 thorpej void *cb_data;
605 1.12 lukem
606 1.25 lukem /* retval may be NULL */
607 1.25 lukem /* disp_tab may be NULL */
608 1.12 lukem _DIAGASSERT(database != NULL);
609 1.12 lukem _DIAGASSERT(method != NULL);
610 1.25 lukem _DIAGASSERT(defaults != NULL);
611 1.25 lukem if (database == NULL || method == NULL || defaults == NULL)
612 1.12 lukem return (NS_UNAVAIL);
613 1.2 lukem
614 1.23 thorpej /*
615 1.23 thorpej * In both the threaded and non-threaded cases, avoid reloading
616 1.23 thorpej * the configuration if the current thread is already running
617 1.23 thorpej * nsdispatch() (i.e. recursive call).
618 1.23 thorpej *
619 1.23 thorpej * In the non-threaded case, this avoids changing the data structures
620 1.23 thorpej * while we're using them.
621 1.23 thorpej *
622 1.23 thorpej * In the threaded case, this avoids trying to take a write lock
623 1.23 thorpej * while the current thread holds a read lock (which would result
624 1.23 thorpej * in deadlock).
625 1.23 thorpej */
626 1.23 thorpej #ifdef _REENTRANT
627 1.23 thorpej if (__isthreaded) {
628 1.23 thorpej drec.thr = thr_self();
629 1.23 thorpej mutex_lock(&_ns_drec_lock);
630 1.23 thorpej LIST_FOREACH(ldrec, &_ns_drec, list) {
631 1.23 thorpej if (ldrec->thr == drec.thr)
632 1.23 thorpej break;
633 1.23 thorpej }
634 1.23 thorpej LIST_INSERT_HEAD(&_ns_drec, &drec, list);
635 1.23 thorpej mutex_unlock(&_ns_drec_lock);
636 1.23 thorpej if (ldrec == NULL && _nsconfigure()) {
637 1.23 thorpej mutex_lock(&_ns_drec_lock);
638 1.23 thorpej LIST_REMOVE(&drec, list);
639 1.23 thorpej mutex_unlock(&_ns_drec_lock);
640 1.23 thorpej return (NS_UNAVAIL);
641 1.23 thorpej }
642 1.29 thorpej } else
643 1.29 thorpej #endif /* _REENTRANT */
644 1.29 thorpej if (_nsdispatching++ == 0 && _nsconfigure()) {
645 1.29 thorpej _nsdispatching--;
646 1.29 thorpej return (NS_UNAVAIL);
647 1.23 thorpej }
648 1.22 thorpej
649 1.22 thorpej rwlock_rdlock(&_nslock);
650 1.22 thorpej
651 1.22 thorpej key.name = database;
652 1.22 thorpej dbt = bsearch(&key, _nsmap, _nsmapsize, sizeof(*_nsmap), _nsdbtcmp);
653 1.5 lukem if (dbt != NULL) {
654 1.5 lukem srclist = dbt->srclist;
655 1.5 lukem srclistsize = dbt->srclistsize;
656 1.5 lukem } else {
657 1.5 lukem srclist = defaults;
658 1.5 lukem srclistsize = 0;
659 1.5 lukem while (srclist[srclistsize].name != NULL)
660 1.5 lukem srclistsize++;
661 1.5 lukem }
662 1.2 lukem result = 0;
663 1.2 lukem
664 1.5 lukem for (i = 0; i < srclistsize; i++) {
665 1.22 thorpej cb = _nsmethod(srclist[i].name, database, method,
666 1.22 thorpej disp_tab, &cb_data);
667 1.2 lukem result = 0;
668 1.22 thorpej if (cb != NULL) {
669 1.5 lukem va_start(ap, defaults);
670 1.22 thorpej result = (*cb)(retval, cb_data, ap);
671 1.2 lukem va_end(ap);
672 1.26 lukem if (defaults[0].flags & NS_FORCEALL)
673 1.26 lukem continue;
674 1.22 thorpej if (result & srclist[i].flags)
675 1.2 lukem break;
676 1.2 lukem }
677 1.2 lukem }
678 1.27 lukem result &= NS_STATUSMASK; /* clear private flags in result */
679 1.22 thorpej
680 1.22 thorpej rwlock_unlock(&_nslock);
681 1.22 thorpej
682 1.23 thorpej #ifdef _REENTRANT
683 1.23 thorpej if (__isthreaded) {
684 1.23 thorpej mutex_lock(&_ns_drec_lock);
685 1.23 thorpej LIST_REMOVE(&drec, list);
686 1.23 thorpej mutex_unlock(&_ns_drec_lock);
687 1.23 thorpej } else
688 1.23 thorpej #endif /* _REENTRANT */
689 1.29 thorpej _nsdispatching--;
690 1.23 thorpej
691 1.2 lukem return (result ? result : NS_NOTFOUND);
692 1.2 lukem }
693