1 /* Copyright (C) 1996-2015 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, see
17 <http://www.gnu.org/licenses/>. */
23 #include <bits/libc-lock.h>
26 #include <stdio_ext.h>
32 #include <netinet/ether.h>
36 #if !defined DO_STATIC_NSS || defined SHARED
37 # include <gnu/lib-names.h>
41 #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)
49 #if !defined DO_STATIC_NSS || defined SHARED
50 static service_library *nss_new_service (name_database *database,
51 const char *name) internal_function;
55 /* Declare external database variables. */
56 #define DEFINE_DATABASE(name) \
57 extern service_user *__nss_##name##_database attribute_hidden; \
58 weak_extern (__nss_##name##_database)
59 #include "databases.def"
60 #undef DEFINE_DATABASE
62 /* Structure to map database name to variable. */
69 #define DEFINE_DATABASE(name) \
70 { #name, &__nss_##name##_database },
71 #include "databases.def"
72 #undef DEFINE_DATABASE
74 #define ndatabases (sizeof (databases) / sizeof (databases[0]))
76 /* Flags whether custom rules for database is set. */
77 bool __nss_database_custom[NSS_DBSIDX_max];
80 __libc_lock_define_initialized (static, lock)
82 #if !defined DO_STATIC_NSS || defined SHARED
83 /* String with revision number of the shared object files. */
84 static const char *const __nss_shlib_revision = LIBNSS_FILES_SO + 15;
87 /* The root of the whole data base. */
88 static name_database *service_table;
90 /* List of default service lists that were generated by glibc because
91 /etc/nsswitch.conf did not provide a value.
92 The list is only maintained so we can free such service lists in
94 static name_database_entry *defconfig_entries;
98 /* Nonzero if this is the nscd process. */
100 /* The callback passed to the init functions when nscd is used. */
101 static void (*nscd_init_cb) (size_t, struct traced_file *);
105 /* -1 == database not found
106 0 == database entry pointer stored */
108 __nss_database_lookup (const char *database, const char *alternate_name,
109 const char *defconfig, service_user **ni)
111 /* Prevent multiple threads to change the service table. */
112 __libc_lock_lock (lock);
114 /* Reconsider database variable in case some other thread called
115 `__nss_configure_lookup' while we waited for the lock. */
118 __libc_lock_unlock (lock);
122 /* Are we initialized yet? */
123 if (service_table == NULL)
124 /* Read config file. */
125 service_table = nss_parse_file (_PATH_NSSWITCH_CONF);
127 /* Test whether configuration data is available. */
128 if (service_table != NULL)
130 /* Return first `service_user' entry for DATABASE. */
131 name_database_entry *entry;
133 /* XXX Could use some faster mechanism here. But each database is
134 only requested once and so this might not be critical. */
135 for (entry = service_table->entry; entry != NULL; entry = entry->next)
136 if (strcmp (database, entry->name) == 0)
137 *ni = entry->service;
139 if (*ni == NULL && alternate_name != NULL)
140 /* We haven't found an entry so far. Try to find it with the
142 for (entry = service_table->entry; entry != NULL; entry = entry->next)
143 if (strcmp (alternate_name, entry->name) == 0)
144 *ni = entry->service;
147 /* No configuration data is available, either because nsswitch.conf
148 doesn't exist or because it doesn't have a line for this database.
150 DEFCONFIG specifies the default service list for this database,
151 or null to use the most common default. */
154 *ni = nss_parse_service_list (defconfig
155 ?: "nis [NOTFOUND=return] files");
158 /* Record the memory we've just allocated in defconfig_entries list,
159 so we can free it later. */
160 name_database_entry *entry;
162 /* Allocate ENTRY plus size of name (1 here). */
163 entry = (name_database_entry *) malloc (sizeof (*entry) + 1);
167 entry->next = defconfig_entries;
168 entry->service = *ni;
169 entry->name[0] = '\0';
170 defconfig_entries = entry;
175 __libc_lock_unlock (lock);
177 return *ni != NULL ? 0 : -1;
179 libc_hidden_def (__nss_database_lookup)
186 __nss_lookup (service_user **ni, const char *fct_name, const char *fct2_name,
189 *fctp = __nss_lookup_function (*ni, fct_name);
190 if (*fctp == NULL && fct2_name != NULL)
191 *fctp = __nss_lookup_function (*ni, fct2_name);
194 && nss_next_action (*ni, NSS_STATUS_UNAVAIL) == NSS_ACTION_CONTINUE
195 && (*ni)->next != NULL)
199 *fctp = __nss_lookup_function (*ni, fct_name);
200 if (*fctp == NULL && fct2_name != NULL)
201 *fctp = __nss_lookup_function (*ni, fct2_name);
204 return *fctp != NULL ? 0 : (*ni)->next == NULL ? 1 : -1;
206 libc_hidden_def (__nss_lookup)
210 0 == adjusted for next function
213 __nss_next2 (service_user **ni, const char *fct_name, const char *fct2_name,
214 void **fctp, int status, int all_values)
218 if (nss_next_action (*ni, NSS_STATUS_TRYAGAIN) == NSS_ACTION_RETURN
219 && nss_next_action (*ni, NSS_STATUS_UNAVAIL) == NSS_ACTION_RETURN
220 && nss_next_action (*ni, NSS_STATUS_NOTFOUND) == NSS_ACTION_RETURN
221 && nss_next_action (*ni, NSS_STATUS_SUCCESS) == NSS_ACTION_RETURN)
226 /* This is really only for debugging. */
227 if (__builtin_expect (NSS_STATUS_TRYAGAIN > status
228 || status > NSS_STATUS_RETURN, 0))
229 __libc_fatal ("illegal status in __nss_next");
231 if (nss_next_action (*ni, status) == NSS_ACTION_RETURN)
235 if ((*ni)->next == NULL)
242 *fctp = __nss_lookup_function (*ni, fct_name);
243 if (*fctp == NULL && fct2_name != NULL)
244 *fctp = __nss_lookup_function (*ni, fct2_name);
247 && nss_next_action (*ni, NSS_STATUS_UNAVAIL) == NSS_ACTION_CONTINUE
248 && (*ni)->next != NULL);
250 return *fctp != NULL ? 0 : -1;
252 libc_hidden_def (__nss_next2)
256 attribute_compat_text_section
257 __nss_next (service_user **ni, const char *fct_name, void **fctp, int status,
260 return __nss_next2 (ni, fct_name, NULL, fctp, status, all_values);
265 __nss_configure_lookup (const char *dbname, const char *service_line)
267 service_user *new_db;
270 for (cnt = 0; cnt < ndatabases; ++cnt)
272 int cmp = strcmp (dbname, databases[cnt].name);
277 __set_errno (EINVAL);
282 if (cnt == ndatabases)
284 __set_errno (EINVAL);
288 /* Test whether it is really used. */
289 if (databases[cnt].dbp == NULL)
290 /* Nothing to do, but we could do. */
293 /* Try to generate new data. */
294 new_db = nss_parse_service_list (service_line);
297 /* Illegal service specification. */
298 __set_errno (EINVAL);
302 /* Prevent multiple threads to change the service table. */
303 __libc_lock_lock (lock);
305 /* Install new rules. */
306 *databases[cnt].dbp = new_db;
307 __nss_database_custom[cnt] = true;
309 __libc_lock_unlock (lock);
315 /* Comparison function for searching NI->known tree. */
317 known_compare (const void *p1, const void *p2)
319 return p1 == p2 ? 0 : strcmp (*(const char *const *) p1,
320 *(const char *const *) p2);
324 #if !defined DO_STATIC_NSS || defined SHARED
327 nss_load_library (service_user *ni)
329 if (ni->library == NULL)
331 /* This service has not yet been used. Fetch the service
332 library for it, creating a new one if need be. If there
333 is no service table from the file, this static variable
334 holds the head of the service_library list made from the
335 default configuration. */
336 static name_database default_table;
337 ni->library = nss_new_service (service_table ?: &default_table,
339 if (ni->library == NULL)
343 if (ni->library->lib_handle == NULL)
345 /* Load the shared library. */
346 size_t shlen = (7 + strlen (ni->name) + 3
347 + strlen (__nss_shlib_revision) + 1);
348 int saved_errno = errno;
349 char shlib_name[shlen];
351 /* Construct shared object name. */
352 __stpcpy (__stpcpy (__stpcpy (__stpcpy (shlib_name,
356 __nss_shlib_revision);
358 ni->library->lib_handle = __libc_dlopen (shlib_name);
359 if (ni->library->lib_handle == NULL)
361 /* Failed to load the library. */
362 ni->library->lib_handle = (void *) -1l;
363 __set_errno (saved_errno);
368 /* Call the init function when nscd is used. */
369 size_t initlen = (5 + strlen (ni->name)
370 + strlen ("_init") + 1);
371 char init_name[initlen];
373 /* Construct the init function name. */
374 __stpcpy (__stpcpy (__stpcpy (init_name,
379 /* Find the optional init function. */
380 void (*ifct) (void (*) (size_t, struct traced_file *))
381 = __libc_dlsym (ni->library->lib_handle, init_name);
384 void (*cb) (size_t, struct traced_file *) = nscd_init_cb;
400 __nss_lookup_function (service_user *ni, const char *fct_name)
402 void **found, *result;
404 /* We now modify global data. Protect it. */
405 __libc_lock_lock (lock);
407 /* Search the tree of functions previously requested. Data in the
408 tree are `known_function' structures, whose first member is a
409 `const char *', the lookup key. The search returns a pointer to
410 the tree node structure; the first member of the is a pointer to
411 our structure (i.e. what will be a `known_function'); since the
412 first member of that is the lookup key string, &FCT_NAME is close
413 enough to a pointer to our structure to use as a lookup key that
414 will be passed to `known_compare' (above). */
416 found = __tsearch (&fct_name, &ni->known, &known_compare);
418 /* This means out-of-memory. */
420 else if (*found != &fct_name)
422 /* The search found an existing structure in the tree. */
423 result = ((known_function *) *found)->fct_ptr;
425 PTR_DEMANGLE (result);
430 /* This name was not known before. Now we have a node in the tree
431 (in the proper sorted position for FCT_NAME) that points to
432 &FCT_NAME instead of any real `known_function' structure.
433 Allocate a new structure and fill it in. */
435 known_function *known = malloc (sizeof *known);
438 #if !defined DO_STATIC_NSS || defined SHARED
441 /* Oops. We can't instantiate this node properly.
442 Remove it from the tree. */
443 __tdelete (&fct_name, &ni->known, &known_compare);
449 /* Point the tree node at this new structure. */
451 known->fct_name = fct_name;
453 #if !defined DO_STATIC_NSS || defined SHARED
454 /* Load the appropriate library. */
455 if (nss_load_library (ni) != 0)
456 /* This only happens when out of memory. */
457 goto remove_from_tree;
459 if (ni->library->lib_handle == (void *) -1l)
460 /* Library not found => function not found. */
464 /* Get the desired function. */
465 size_t namlen = (5 + strlen (ni->name) + 1
466 + strlen (fct_name) + 1);
469 /* Construct the function name. */
470 __stpcpy (__stpcpy (__stpcpy (__stpcpy (name, "_nss_"),
475 /* Look up the symbol. */
476 result = __libc_dlsym (ni->library->lib_handle, name);
479 /* We can't get function address dynamically in static linking. */
481 # define DEFINE_ENT(h,nm) \
482 { #h"_get"#nm"ent_r", _nss_##h##_get##nm##ent_r }, \
483 { #h"_end"#nm"ent", _nss_##h##_end##nm##ent }, \
484 { #h"_set"#nm"ent", _nss_##h##_set##nm##ent },
485 # define DEFINE_GET(h,nm) \
486 { #h"_get"#nm"_r", _nss_##h##_get##nm##_r },
487 # define DEFINE_GETBY(h,nm,ky) \
488 { #h"_get"#nm"by"#ky"_r", _nss_##h##_get##nm##by##ky##_r },
489 static struct fct_tbl { const char *fname; void *fp; } *tp, tbl[] =
491 # include "function.def"
494 size_t namlen = (5 + strlen (ni->name) + 1
495 + strlen (fct_name) + 1);
498 /* Construct the function name. */
499 __stpcpy (__stpcpy (__stpcpy (name, ni->name),
504 for (tp = &tbl[0]; tp->fname; tp++)
505 if (strcmp (tp->fname, name) == 0)
513 /* Remember function pointer for later calls. Even if null, we
514 record it so a second try needn't search the library again. */
515 known->fct_ptr = result;
517 PTR_MANGLE (known->fct_ptr);
522 /* Remove the lock. */
523 __libc_lock_unlock (lock);
527 libc_hidden_def (__nss_lookup_function)
530 static name_database *
532 nss_parse_file (const char *fname)
535 name_database *result;
536 name_database_entry *last;
540 /* Open the configuration file. */
541 fp = fopen (fname, "rce");
545 /* No threads use this stream. */
546 __fsetlocking (fp, FSETLOCKING_BYCALLER);
548 result = (name_database *) malloc (sizeof (name_database));
555 result->entry = NULL;
556 result->library = NULL;
562 name_database_entry *this;
565 n = __getline (&line, &len, fp);
568 if (line[n - 1] == '\n')
571 /* Because the file format does not know any form of quoting we
572 can search forward for the next '#' character and if found
573 make it terminating the line. */
574 *__strchrnul (line, '#') = '\0';
576 /* If the line is blank it is ignored. */
580 /* Each line completely specifies the actions for a database. */
581 this = nss_getline (line);
587 result->entry = this;
592 while (!feof_unlocked (fp));
594 /* Free the buffer. */
596 /* Close configuration file. */
603 /* Read the source names:
604 `( <source> ( "[" "!"? (<status> "=" <action> )+ "]" )? )*'
606 static service_user *
608 nss_parse_service_list (const char *line)
610 service_user *result = NULL, **nextp = &result;
614 service_user *new_service;
617 while (isspace (line[0]))
620 /* No source specified. */
623 /* Read <source> identifier. */
625 while (line[0] != '\0' && !isspace (line[0]) && line[0] != '[')
631 new_service = (service_user *) malloc (sizeof (service_user)
632 + (line - name + 1));
633 if (new_service == NULL)
636 *((char *) __mempcpy (new_service->name, name, line - name)) = '\0';
638 /* Set default actions. */
639 new_service->actions[2 + NSS_STATUS_TRYAGAIN] = NSS_ACTION_CONTINUE;
640 new_service->actions[2 + NSS_STATUS_UNAVAIL] = NSS_ACTION_CONTINUE;
641 new_service->actions[2 + NSS_STATUS_NOTFOUND] = NSS_ACTION_CONTINUE;
642 new_service->actions[2 + NSS_STATUS_SUCCESS] = NSS_ACTION_RETURN;
643 new_service->actions[2 + NSS_STATUS_RETURN] = NSS_ACTION_RETURN;
644 new_service->library = NULL;
645 new_service->known = NULL;
646 new_service->next = NULL;
648 while (isspace (line[0]))
653 /* Read criterions. */
656 while (line[0] != '\0' && isspace (line[0]));
661 enum nss_status status;
662 lookup_actions action;
664 /* Grok ! before name to mean all statii but that one. */
665 not = line[0] == '!';
669 /* Read status name. */
671 while (line[0] != '\0' && !isspace (line[0]) && line[0] != '='
675 /* Compare with known statii. */
676 if (line - name == 7)
678 if (__strncasecmp (name, "SUCCESS", 7) == 0)
679 status = NSS_STATUS_SUCCESS;
680 else if (__strncasecmp (name, "UNAVAIL", 7) == 0)
681 status = NSS_STATUS_UNAVAIL;
685 else if (line - name == 8)
687 if (__strncasecmp (name, "NOTFOUND", 8) == 0)
688 status = NSS_STATUS_NOTFOUND;
689 else if (__strncasecmp (name, "TRYAGAIN", 8) == 0)
690 status = NSS_STATUS_TRYAGAIN;
697 while (isspace (line[0]))
703 while (isspace (line[0]));
706 while (line[0] != '\0' && !isspace (line[0]) && line[0] != '='
710 if (line - name == 6 && __strncasecmp (name, "RETURN", 6) == 0)
711 action = NSS_ACTION_RETURN;
712 else if (line - name == 8
713 && __strncasecmp (name, "CONTINUE", 8) == 0)
714 action = NSS_ACTION_CONTINUE;
720 /* Save the current action setting for this status,
721 set them all to the given action, and reset this one. */
722 const lookup_actions save = new_service->actions[2 + status];
723 new_service->actions[2 + NSS_STATUS_TRYAGAIN] = action;
724 new_service->actions[2 + NSS_STATUS_UNAVAIL] = action;
725 new_service->actions[2 + NSS_STATUS_NOTFOUND] = action;
726 new_service->actions[2 + NSS_STATUS_SUCCESS] = action;
727 new_service->actions[2 + status] = save;
730 new_service->actions[2 + status] = action;
732 /* Skip white spaces. */
733 while (isspace (line[0]))
736 while (line[0] != ']');
742 *nextp = new_service;
743 nextp = &new_service->next;
752 static name_database_entry *
754 nss_getline (char *line)
757 name_database_entry *result;
760 /* Ignore leading white spaces. ATTENTION: this is different from
761 what is implemented in Solaris. The Solaris man page says a line
762 beginning with a white space character is ignored. We regard
763 this as just another misfeature in Solaris. */
764 while (isspace (line[0]))
767 /* Recognize `<database> ":"'. */
769 while (line[0] != '\0' && !isspace (line[0]) && line[0] != ':')
771 if (line[0] == '\0' || name == line)
776 len = strlen (name) + 1;
778 result = (name_database_entry *) malloc (sizeof (name_database_entry) + len);
782 /* Save the database name. */
783 memcpy (result->name, name, len);
785 /* Parse the list of services. */
786 result->service = nss_parse_service_list (line);
793 #if !defined DO_STATIC_NSS || defined SHARED
794 static service_library *
796 nss_new_service (name_database *database, const char *name)
798 service_library **currentp = &database->library;
800 while (*currentp != NULL)
802 if (strcmp ((*currentp)->name, name) == 0)
804 currentp = &(*currentp)->next;
807 /* We have to add the new service. */
808 *currentp = (service_library *) malloc (sizeof (service_library));
809 if (*currentp == NULL)
812 (*currentp)->name = name;
813 (*currentp)->lib_handle = NULL;
814 (*currentp)->next = NULL;
821 #if defined SHARED && defined USE_NSCD
822 /* Load all libraries for the service. */
824 nss_load_all_libraries (const char *service, const char *def)
826 service_user *ni = NULL;
828 if (__nss_database_lookup (service, NULL, def, &ni) == 0)
831 nss_load_library (ni);
837 /* Called by nscd and nscd alone. */
839 __nss_disable_nscd (void (*cb) (size_t, struct traced_file *))
847 /* Find all the relevant modules so that the init functions are called. */
848 nss_load_all_libraries ("passwd", "compat [NOTFOUND=return] files");
849 nss_load_all_libraries ("group", "compat [NOTFOUND=return] files");
850 nss_load_all_libraries ("hosts", "dns [!UNAVAIL=return] files");
851 nss_load_all_libraries ("services", NULL);
853 /* Disable all uses of NSCD. */
854 __nss_not_use_nscd_passwd = -1;
855 __nss_not_use_nscd_group = -1;
856 __nss_not_use_nscd_hosts = -1;
857 __nss_not_use_nscd_services = -1;
858 __nss_not_use_nscd_netgroup = -1;
863 free_database_entries (name_database_entry *entry)
865 while (entry != NULL)
867 name_database_entry *olde = entry;
868 service_user *service = entry->service;
870 while (service != NULL)
872 service_user *olds = service;
874 if (service->known != NULL)
875 __tdestroy (service->known, free);
877 service = service->next;
886 /* Free all resources if necessary. */
887 libc_freeres_fn (free_defconfig)
889 name_database_entry *entry = defconfig_entries;
892 /* defconfig was not used. */
895 /* Don't disturb ongoing other threads (if there are any). */
896 defconfig_entries = NULL;
898 free_database_entries (entry);
901 libc_freeres_fn (free_mem)
903 name_database *top = service_table;
904 service_library *library;
907 /* Maybe we have not read the nsswitch.conf file. */
910 /* Don't disturb ongoing other threads (if there are any). */
911 service_table = NULL;
913 free_database_entries (top->entry);
915 library = top->library;
916 while (library != NULL)
918 service_library *oldl = library;
920 if (library->lib_handle && library->lib_handle != (void *) -1l)
921 __libc_dlclose (library->lib_handle);
923 library = library->next;