* sysdeps/gnu/netinet/tcp.h: Define TCP_MD5SIG, TCP_MD5SIG_MAXKEYLEN,
[glibc.git] / nss / nsswitch.c
blob46965fd8ff862da1d0a7ad24eef598f0863c55b5
1 /* Copyright (C) 1996-1999, 2001-2006, 2007 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, write to the Free
17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
18 02111-1307 USA. */
20 #include <ctype.h>
21 #include <dlfcn.h>
22 #include <errno.h>
23 #include <netdb.h>
24 #include <bits/libc-lock.h>
25 #include <search.h>
26 #include <stdio.h>
27 #include <stdio_ext.h>
28 #include <stdlib.h>
29 #include <string.h>
31 #include <aliases.h>
32 #include <grp.h>
33 #include <netinet/ether.h>
34 #include <pwd.h>
35 #include <shadow.h>
37 #if !defined DO_STATIC_NSS || defined SHARED
38 # include <gnu/lib-names.h>
39 #endif
41 #include "nsswitch.h"
42 #include "../nscd/nscd_proto.h"
44 /* Prototypes for the local functions. */
45 static name_database *nss_parse_file (const char *fname) internal_function;
46 static name_database_entry *nss_getline (char *line) internal_function;
47 static service_user *nss_parse_service_list (const char *line)
48 internal_function;
49 static service_library *nss_new_service (name_database *database,
50 const char *name) internal_function;
53 /* Declare external database variables. */
54 #define DEFINE_DATABASE(name) \
55 extern service_user *__nss_##name##_database attribute_hidden; \
56 weak_extern (__nss_##name##_database)
57 #include "databases.def"
58 #undef DEFINE_DATABASE
60 /* Structure to map database name to variable. */
61 static const struct
63 const char name[10];
64 service_user **dbp;
65 } databases[] =
67 #define DEFINE_DATABASE(name) \
68 { #name, &__nss_##name##_database },
69 #include "databases.def"
70 #undef DEFINE_DATABASE
72 #define ndatabases (sizeof (databases) / sizeof (databases[0]))
75 __libc_lock_define_initialized (static, lock)
77 #if !defined DO_STATIC_NSS || defined SHARED
78 /* String with revision number of the shared object files. */
79 static const char *const __nss_shlib_revision = LIBNSS_FILES_SO + 15;
80 #endif
82 /* The root of the whole data base. */
83 static name_database *service_table;
86 /* -1 == database not found
87 0 == database entry pointer stored */
88 int
89 __nss_database_lookup (const char *database, const char *alternate_name,
90 const char *defconfig, service_user **ni)
92 /* Prevent multiple threads to change the service table. */
93 __libc_lock_lock (lock);
95 /* Reconsider database variable in case some other thread called
96 `__nss_configure_lookup' while we waited for the lock. */
97 if (*ni != NULL)
99 __libc_lock_unlock (lock);
100 return 0;
103 /* Are we initialized yet? */
104 if (service_table == NULL)
105 /* Read config file. */
106 service_table = nss_parse_file (_PATH_NSSWITCH_CONF);
108 /* Test whether configuration data is available. */
109 if (service_table != NULL)
111 /* Return first `service_user' entry for DATABASE. */
112 name_database_entry *entry;
114 /* XXX Could use some faster mechanism here. But each database is
115 only requested once and so this might not be critical. */
116 for (entry = service_table->entry; entry != NULL; entry = entry->next)
117 if (strcmp (database, entry->name) == 0)
118 *ni = entry->service;
120 if (*ni == NULL && alternate_name != NULL)
121 /* We haven't found an entry so far. Try to find it with the
122 alternative name. */
123 for (entry = service_table->entry; entry != NULL; entry = entry->next)
124 if (strcmp (alternate_name, entry->name) == 0)
125 *ni = entry->service;
128 /* No configuration data is available, either because nsswitch.conf
129 doesn't exist or because it doesn't has a line for this database.
131 DEFCONFIG specifies the default service list for this database,
132 or null to use the most common default. */
133 if (*ni == NULL)
134 *ni = nss_parse_service_list (defconfig
135 ?: "nis [NOTFOUND=return] files");
137 __libc_lock_unlock (lock);
139 return 0;
141 libc_hidden_def (__nss_database_lookup)
144 /* -1 == not found
145 0 == function found
146 1 == finished */
148 __nss_lookup (service_user **ni, const char *fct_name, void **fctp)
150 *fctp = __nss_lookup_function (*ni, fct_name);
152 while (*fctp == NULL
153 && nss_next_action (*ni, NSS_STATUS_UNAVAIL) == NSS_ACTION_CONTINUE
154 && (*ni)->next != NULL)
156 *ni = (*ni)->next;
158 *fctp = __nss_lookup_function (*ni, fct_name);
161 return *fctp != NULL ? 0 : (*ni)->next == NULL ? 1 : -1;
165 /* -1 == not found
166 0 == adjusted for next function
167 1 == finished */
169 __nss_next (service_user **ni, const char *fct_name, void **fctp, int status,
170 int all_values)
172 if (all_values)
174 if (nss_next_action (*ni, NSS_STATUS_TRYAGAIN) == NSS_ACTION_RETURN
175 && nss_next_action (*ni, NSS_STATUS_UNAVAIL) == NSS_ACTION_RETURN
176 && nss_next_action (*ni, NSS_STATUS_NOTFOUND) == NSS_ACTION_RETURN
177 && nss_next_action (*ni, NSS_STATUS_SUCCESS) == NSS_ACTION_RETURN)
178 return 1;
180 else
182 /* This is really only for debugging. */
183 if (NSS_STATUS_TRYAGAIN > status || status > NSS_STATUS_RETURN)
184 __libc_fatal ("illegal status in __nss_next");
186 if (nss_next_action (*ni, status) == NSS_ACTION_RETURN)
187 return 1;
190 if ((*ni)->next == NULL)
191 return -1;
195 *ni = (*ni)->next;
197 *fctp = __nss_lookup_function (*ni, fct_name);
199 while (*fctp == NULL
200 && nss_next_action (*ni, NSS_STATUS_UNAVAIL) == NSS_ACTION_CONTINUE
201 && (*ni)->next != NULL);
203 return *fctp != NULL ? 0 : -1;
205 libc_hidden_def (__nss_next)
209 __nss_configure_lookup (const char *dbname, const char *service_line)
211 service_user *new_db;
212 size_t cnt;
214 for (cnt = 0; cnt < ndatabases; ++cnt)
216 int cmp = strcmp (dbname, databases[cnt].name);
217 if (cmp == 0)
218 break;
219 if (cmp < 0)
221 __set_errno (EINVAL);
222 return -1;
226 if (cnt == ndatabases)
228 __set_errno (EINVAL);
229 return -1;
232 /* Test whether it is really used. */
233 if (databases[cnt].dbp == NULL)
234 /* Nothing to do, but we could do. */
235 return 0;
237 /* Try to generate new data. */
238 new_db = nss_parse_service_list (service_line);
239 if (new_db == NULL)
241 /* Illegal service specification. */
242 __set_errno (EINVAL);
243 return -1;
246 /* Prevent multiple threads to change the service table. */
247 __libc_lock_lock (lock);
249 /* Install new rules. */
250 *databases[cnt].dbp = new_db;
252 __libc_lock_unlock (lock);
254 return 0;
258 /* Comparison function for searching NI->known tree. */
259 static int
260 known_compare (const void *p1, const void *p2)
262 return p1 == p2 ? 0 : strcmp (*(const char *const *) p1,
263 *(const char *const *) p2);
267 void *
268 __nss_lookup_function (service_user *ni, const char *fct_name)
270 void **found, *result;
272 /* We now modify global data. Protect it. */
273 __libc_lock_lock (lock);
275 /* Search the tree of functions previously requested. Data in the
276 tree are `known_function' structures, whose first member is a
277 `const char *', the lookup key. The search returns a pointer to
278 the tree node structure; the first member of the is a pointer to
279 our structure (i.e. what will be a `known_function'); since the
280 first member of that is the lookup key string, &FCT_NAME is close
281 enough to a pointer to our structure to use as a lookup key that
282 will be passed to `known_compare' (above). */
284 found = __tsearch (&fct_name, &ni->known, &known_compare);
285 if (*found != &fct_name)
286 /* The search found an existing structure in the tree. */
287 result = ((known_function *) *found)->fct_ptr;
288 else
290 /* This name was not known before. Now we have a node in the tree
291 (in the proper sorted position for FCT_NAME) that points to
292 &FCT_NAME instead of any real `known_function' structure.
293 Allocate a new structure and fill it in. */
295 known_function *known = malloc (sizeof *known);
296 if (! known)
298 remove_from_tree:
299 /* Oops. We can't instantiate this node properly.
300 Remove it from the tree. */
301 __tdelete (&fct_name, &ni->known, &known_compare);
302 result = NULL;
304 else
306 /* Point the tree node at this new structure. */
307 *found = known;
308 known->fct_name = fct_name;
310 if (ni->library == NULL)
312 /* This service has not yet been used. Fetch the service
313 library for it, creating a new one if need be. If there
314 is no service table from the file, this static variable
315 holds the head of the service_library list made from the
316 default configuration. */
317 static name_database default_table;
318 ni->library = nss_new_service (service_table ?: &default_table,
319 ni->name);
320 if (ni->library == NULL)
322 /* This only happens when out of memory. */
323 free (known);
324 goto remove_from_tree;
328 #if !defined DO_STATIC_NSS || defined SHARED
329 if (ni->library->lib_handle == NULL)
331 /* Load the shared library. */
332 size_t shlen = (7 + strlen (ni->library->name) + 3
333 + strlen (__nss_shlib_revision) + 1);
334 int saved_errno = errno;
335 char shlib_name[shlen];
337 /* Construct shared object name. */
338 __stpcpy (__stpcpy (__stpcpy (__stpcpy (shlib_name,
339 "libnss_"),
340 ni->library->name),
341 ".so"),
342 __nss_shlib_revision);
344 ni->library->lib_handle = __libc_dlopen (shlib_name);
345 if (ni->library->lib_handle == NULL)
347 /* Failed to load the library. */
348 ni->library->lib_handle = (void *) -1l;
349 __set_errno (saved_errno);
353 if (ni->library->lib_handle == (void *) -1l)
354 /* Library not found => function not found. */
355 result = NULL;
356 else
358 /* Get the desired function. */
359 size_t namlen = (5 + strlen (ni->library->name) + 1
360 + strlen (fct_name) + 1);
361 char name[namlen];
363 /* Construct the function name. */
364 __stpcpy (__stpcpy (__stpcpy (__stpcpy (name, "_nss_"),
365 ni->library->name),
366 "_"),
367 fct_name);
369 /* Look up the symbol. */
370 result = __libc_dlsym (ni->library->lib_handle, name);
372 #else
373 /* We can't get function address dynamically in static linking. */
375 # define DEFINE_ENT(h,nm) \
376 { #h"_get"#nm"ent_r", _nss_##h##_get##nm##ent_r }, \
377 { #h"_end"#nm"ent", _nss_##h##_end##nm##ent }, \
378 { #h"_set"#nm"ent", _nss_##h##_set##nm##ent },
379 # define DEFINE_GET(h,nm) \
380 { #h"_get"#nm"_r", _nss_##h##_get##nm##_r },
381 # define DEFINE_GETBY(h,nm,ky) \
382 { #h"_get"#nm"by"#ky"_r", _nss_##h##_get##nm##by##ky##_r },
383 static struct fct_tbl { const char *fname; void *fp; } *tp, tbl[] =
385 # include "function.def"
386 { NULL, NULL }
388 size_t namlen = (5 + strlen (ni->library->name) + 1
389 + strlen (fct_name) + 1);
390 char name[namlen];
392 /* Construct the function name. */
393 __stpcpy (__stpcpy (__stpcpy (name, ni->library->name),
394 "_"),
395 fct_name);
397 result = NULL;
398 for (tp = &tbl[0]; tp->fname; tp++)
399 if (strcmp (tp->fname, name) == 0)
401 result = tp->fp;
402 break;
405 #endif
407 /* Remember function pointer for later calls. Even if null, we
408 record it so a second try needn't search the library again. */
409 known->fct_ptr = result;
413 /* Remove the lock. */
414 __libc_lock_unlock (lock);
416 return result;
418 libc_hidden_def (__nss_lookup_function)
421 static name_database *
422 internal_function
423 nss_parse_file (const char *fname)
425 FILE *fp;
426 name_database *result;
427 name_database_entry *last;
428 char *line;
429 size_t len;
431 /* Open the configuration file. */
432 fp = fopen (fname, "rc");
433 if (fp == NULL)
434 return NULL;
436 /* No threads use this stream. */
437 __fsetlocking (fp, FSETLOCKING_BYCALLER);
439 result = (name_database *) malloc (sizeof (name_database));
440 if (result == NULL)
441 return NULL;
443 result->entry = NULL;
444 result->library = NULL;
445 last = NULL;
446 line = NULL;
447 len = 0;
450 name_database_entry *this;
451 ssize_t n;
453 n = __getline (&line, &len, fp);
454 if (n < 0)
455 break;
456 if (line[n - 1] == '\n')
457 line[n - 1] = '\0';
459 /* Because the file format does not know any form of quoting we
460 can search forward for the next '#' character and if found
461 make it terminating the line. */
462 *__strchrnul (line, '#') = '\0';
464 /* If the line is blank it is ignored. */
465 if (line[0] == '\0')
466 continue;
468 /* Each line completely specifies the actions for a database. */
469 this = nss_getline (line);
470 if (this != NULL)
472 if (last != NULL)
473 last->next = this;
474 else
475 result->entry = this;
477 last = this;
480 while (!feof_unlocked (fp));
482 /* Free the buffer. */
483 free (line);
484 /* Close configuration file. */
485 fclose (fp);
487 return result;
491 /* Read the source names:
492 `( <source> ( "[" "!"? (<status> "=" <action> )+ "]" )? )*'
494 static service_user *
495 internal_function
496 nss_parse_service_list (const char *line)
498 service_user *result = NULL, **nextp = &result;
500 while (1)
502 service_user *new_service;
503 const char *name;
505 while (isspace (line[0]))
506 ++line;
507 if (line[0] == '\0')
508 /* No source specified. */
509 return result;
511 /* Read <source> identifier. */
512 name = line;
513 while (line[0] != '\0' && !isspace (line[0]) && line[0] != '[')
514 ++line;
515 if (name == line)
516 return result;
519 new_service = (service_user *) malloc (sizeof (service_user)
520 + (line - name + 1));
521 if (new_service == NULL)
522 return result;
524 *((char *) __mempcpy (new_service->name, name, line - name)) = '\0';
526 /* Set default actions. */
527 new_service->actions[2 + NSS_STATUS_TRYAGAIN] = NSS_ACTION_CONTINUE;
528 new_service->actions[2 + NSS_STATUS_UNAVAIL] = NSS_ACTION_CONTINUE;
529 new_service->actions[2 + NSS_STATUS_NOTFOUND] = NSS_ACTION_CONTINUE;
530 new_service->actions[2 + NSS_STATUS_SUCCESS] = NSS_ACTION_RETURN;
531 new_service->actions[2 + NSS_STATUS_RETURN] = NSS_ACTION_RETURN;
532 new_service->library = NULL;
533 new_service->known = NULL;
534 new_service->next = NULL;
536 while (isspace (line[0]))
537 ++line;
539 if (line[0] == '[')
541 /* Read criterions. */
543 ++line;
544 while (line[0] != '\0' && isspace (line[0]));
548 int not;
549 enum nss_status status;
550 lookup_actions action;
552 /* Grok ! before name to mean all statii but that one. */
553 not = line[0] == '!';
554 if (not)
555 ++line;
557 /* Read status name. */
558 name = line;
559 while (line[0] != '\0' && !isspace (line[0]) && line[0] != '='
560 && line[0] != ']')
561 ++line;
563 /* Compare with known statii. */
564 if (line - name == 7)
566 if (__strncasecmp (name, "SUCCESS", 7) == 0)
567 status = NSS_STATUS_SUCCESS;
568 else if (__strncasecmp (name, "UNAVAIL", 7) == 0)
569 status = NSS_STATUS_UNAVAIL;
570 else
571 return result;
573 else if (line - name == 8)
575 if (__strncasecmp (name, "NOTFOUND", 8) == 0)
576 status = NSS_STATUS_NOTFOUND;
577 else if (__strncasecmp (name, "TRYAGAIN", 8) == 0)
578 status = NSS_STATUS_TRYAGAIN;
579 else
580 return result;
582 else
583 return result;
585 while (isspace (line[0]))
586 ++line;
587 if (line[0] != '=')
588 return result;
590 ++line;
591 while (isspace (line[0]));
593 name = line;
594 while (line[0] != '\0' && !isspace (line[0]) && line[0] != '='
595 && line[0] != ']')
596 ++line;
598 if (line - name == 6 && __strncasecmp (name, "RETURN", 6) == 0)
599 action = NSS_ACTION_RETURN;
600 else if (line - name == 8
601 && __strncasecmp (name, "CONTINUE", 8) == 0)
602 action = NSS_ACTION_CONTINUE;
603 else
604 return result;
606 if (not)
608 /* Save the current action setting for this status,
609 set them all to the given action, and reset this one. */
610 const lookup_actions save = new_service->actions[2 + status];
611 new_service->actions[2 + NSS_STATUS_TRYAGAIN] = action;
612 new_service->actions[2 + NSS_STATUS_UNAVAIL] = action;
613 new_service->actions[2 + NSS_STATUS_NOTFOUND] = action;
614 new_service->actions[2 + NSS_STATUS_SUCCESS] = action;
615 new_service->actions[2 + status] = save;
617 else
618 new_service->actions[2 + status] = action;
620 /* Skip white spaces. */
621 while (isspace (line[0]))
622 ++line;
624 while (line[0] != ']');
626 /* Skip the ']'. */
627 ++line;
630 *nextp = new_service;
631 nextp = &new_service->next;
635 static name_database_entry *
636 internal_function
637 nss_getline (char *line)
639 const char *name;
640 name_database_entry *result;
641 size_t len;
643 /* Ignore leading white spaces. ATTENTION: this is different from
644 what is implemented in Solaris. The Solaris man page says a line
645 beginning with a white space character is ignored. We regard
646 this as just another misfeature in Solaris. */
647 while (isspace (line[0]))
648 ++line;
650 /* Recognize `<database> ":"'. */
651 name = line;
652 while (line[0] != '\0' && !isspace (line[0]) && line[0] != ':')
653 ++line;
654 if (line[0] == '\0' || name == line)
655 /* Syntax error. */
656 return NULL;
657 *line++ = '\0';
659 len = strlen (name) + 1;
661 result = (name_database_entry *) malloc (sizeof (name_database_entry) + len);
662 if (result == NULL)
663 return NULL;
665 /* Save the database name. */
666 memcpy (result->name, name, len);
668 /* Parse the list of services. */
669 result->service = nss_parse_service_list (line);
671 result->next = NULL;
672 return result;
676 static service_library *
677 internal_function
678 nss_new_service (name_database *database, const char *name)
680 service_library **currentp = &database->library;
682 while (*currentp != NULL)
684 if (strcmp ((*currentp)->name, name) == 0)
685 return *currentp;
686 currentp = &(*currentp)->next;
689 /* We have to add the new service. */
690 *currentp = (service_library *) malloc (sizeof (service_library));
691 if (*currentp == NULL)
692 return NULL;
694 (*currentp)->name = name;
695 (*currentp)->lib_handle = NULL;
696 (*currentp)->next = NULL;
698 return *currentp;
702 /* Called by nscd and nscd alone. */
703 void
704 __nss_disable_nscd (void)
706 /* Disable all uses of NSCD. */
707 __nss_not_use_nscd_passwd = -1;
708 __nss_not_use_nscd_group = -1;
709 __nss_not_use_nscd_hosts = -1;
710 __nss_not_use_nscd_services = -1;
714 /* Free all resources if necessary. */
715 libc_freeres_fn (free_mem)
717 name_database *top = service_table;
718 name_database_entry *entry;
719 service_library *library;
721 if (top == NULL)
722 /* Maybe we have not read the nsswitch.conf file. */
723 return;
725 /* Don't disturb ongoing other threads (if there are any). */
726 service_table = NULL;
728 entry = top->entry;
729 while (entry != NULL)
731 name_database_entry *olde = entry;
732 service_user *service = entry->service;
734 while (service != NULL)
736 service_user *olds = service;
738 if (service->known != NULL)
739 __tdestroy (service->known, free);
741 service = service->next;
742 free (olds);
745 entry = entry->next;
746 free (olde);
749 library = top->library;
750 while (library != NULL)
752 service_library *oldl = library;
754 if (library->lib_handle && library->lib_handle != (void *) -1l)
755 __libc_dlclose (library->lib_handle);
757 library = library->next;
758 free (oldl);
761 free (top);