1 /* Copyright (C) 1996-2012 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 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. */
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]))
74 /* Flags whether custom rules for database is set. */
75 bool __nss_database_custom[NSS_DBSIDX_max];
78 __libc_lock_define_initialized (static, lock)
80 #if !defined DO_STATIC_NSS || defined SHARED
81 /* String with revision number of the shared object files. */
82 static const char *const __nss_shlib_revision = LIBNSS_FILES_SO + 15;
85 /* The root of the whole data base. */
86 static name_database *service_table;
88 /* List of default service lists that were generated by glibc because
89 /etc/nsswitch.conf did not provide a value.
90 The list is only maintained so we can free such service lists in
92 static name_database_entry *defconfig_entries;
96 /* Nonzero if this is the nscd process. */
98 /* The callback passed to the init functions when nscd is used. */
99 static void (*nscd_init_cb) (size_t, struct traced_file *);
103 /* -1 == database not found
104 0 == database entry pointer stored */
106 __nss_database_lookup (const char *database, const char *alternate_name,
107 const char *defconfig, service_user **ni)
109 /* Prevent multiple threads to change the service table. */
110 __libc_lock_lock (lock);
112 /* Reconsider database variable in case some other thread called
113 `__nss_configure_lookup' while we waited for the lock. */
116 __libc_lock_unlock (lock);
120 /* Are we initialized yet? */
121 if (service_table == NULL)
122 /* Read config file. */
123 service_table = nss_parse_file (_PATH_NSSWITCH_CONF);
125 /* Test whether configuration data is available. */
126 if (service_table != NULL)
128 /* Return first `service_user' entry for DATABASE. */
129 name_database_entry *entry;
131 /* XXX Could use some faster mechanism here. But each database is
132 only requested once and so this might not be critical. */
133 for (entry = service_table->entry; entry != NULL; entry = entry->next)
134 if (strcmp (database, entry->name) == 0)
135 *ni = entry->service;
137 if (*ni == NULL && alternate_name != NULL)
138 /* We haven't found an entry so far. Try to find it with the
140 for (entry = service_table->entry; entry != NULL; entry = entry->next)
141 if (strcmp (alternate_name, entry->name) == 0)
142 *ni = entry->service;
145 /* No configuration data is available, either because nsswitch.conf
146 doesn't exist or because it doesn't have a line for this database.
148 DEFCONFIG specifies the default service list for this database,
149 or null to use the most common default. */
152 *ni = nss_parse_service_list (defconfig
153 ?: "nis [NOTFOUND=return] files");
156 /* Record the memory we've just allocated in defconfig_entries list,
157 so we can free it later. */
158 name_database_entry *entry;
160 /* Allocate ENTRY plus size of name (1 here). */
161 entry = (name_database_entry *) malloc (sizeof (*entry) + 1);
165 entry->next = defconfig_entries;
166 entry->service = *ni;
167 entry->name[0] = '\0';
168 defconfig_entries = entry;
173 __libc_lock_unlock (lock);
175 return *ni != NULL ? 0 : -1;
177 libc_hidden_def (__nss_database_lookup)
184 __nss_lookup (service_user **ni, const char *fct_name, const char *fct2_name,
187 *fctp = __nss_lookup_function (*ni, fct_name);
188 if (*fctp == NULL && fct2_name != NULL)
189 *fctp = __nss_lookup_function (*ni, fct2_name);
192 && nss_next_action (*ni, NSS_STATUS_UNAVAIL) == NSS_ACTION_CONTINUE
193 && (*ni)->next != NULL)
197 *fctp = __nss_lookup_function (*ni, fct_name);
198 if (*fctp == NULL && fct2_name != NULL)
199 *fctp = __nss_lookup_function (*ni, fct2_name);
202 return *fctp != NULL ? 0 : (*ni)->next == NULL ? 1 : -1;
204 libc_hidden_def (__nss_lookup)
208 0 == adjusted for next function
211 __nss_next2 (service_user **ni, const char *fct_name, const char *fct2_name,
212 void **fctp, int status, int all_values)
216 if (nss_next_action (*ni, NSS_STATUS_TRYAGAIN) == NSS_ACTION_RETURN
217 && nss_next_action (*ni, NSS_STATUS_UNAVAIL) == NSS_ACTION_RETURN
218 && nss_next_action (*ni, NSS_STATUS_NOTFOUND) == NSS_ACTION_RETURN
219 && nss_next_action (*ni, NSS_STATUS_SUCCESS) == NSS_ACTION_RETURN)
224 /* This is really only for debugging. */
225 if (__builtin_expect (NSS_STATUS_TRYAGAIN > status
226 || status > NSS_STATUS_RETURN, 0))
227 __libc_fatal ("illegal status in __nss_next");
229 if (nss_next_action (*ni, status) == NSS_ACTION_RETURN)
233 if ((*ni)->next == NULL)
240 *fctp = __nss_lookup_function (*ni, fct_name);
241 if (*fctp == NULL && fct2_name != NULL)
242 *fctp = __nss_lookup_function (*ni, fct2_name);
245 && nss_next_action (*ni, NSS_STATUS_UNAVAIL) == NSS_ACTION_CONTINUE
246 && (*ni)->next != NULL);
248 return *fctp != NULL ? 0 : -1;
250 libc_hidden_def (__nss_next2)
254 attribute_compat_text_section
255 __nss_next (service_user **ni, const char *fct_name, void **fctp, int status,
258 return __nss_next2 (ni, fct_name, NULL, fctp, status, all_values);
263 __nss_configure_lookup (const char *dbname, const char *service_line)
265 service_user *new_db;
268 for (cnt = 0; cnt < ndatabases; ++cnt)
270 int cmp = strcmp (dbname, databases[cnt].name);
275 __set_errno (EINVAL);
280 if (cnt == ndatabases)
282 __set_errno (EINVAL);
286 /* Test whether it is really used. */
287 if (databases[cnt].dbp == NULL)
288 /* Nothing to do, but we could do. */
291 /* Try to generate new data. */
292 new_db = nss_parse_service_list (service_line);
295 /* Illegal service specification. */
296 __set_errno (EINVAL);
300 /* Prevent multiple threads to change the service table. */
301 __libc_lock_lock (lock);
303 /* Install new rules. */
304 *databases[cnt].dbp = new_db;
305 __nss_database_custom[cnt] = true;
307 __libc_lock_unlock (lock);
313 /* Comparison function for searching NI->known tree. */
315 known_compare (const void *p1, const void *p2)
317 return p1 == p2 ? 0 : strcmp (*(const char *const *) p1,
318 *(const char *const *) p2);
322 #if !defined DO_STATIC_NSS || defined SHARED
325 nss_load_library (service_user *ni)
327 if (ni->library == NULL)
329 /* This service has not yet been used. Fetch the service
330 library for it, creating a new one if need be. If there
331 is no service table from the file, this static variable
332 holds the head of the service_library list made from the
333 default configuration. */
334 static name_database default_table;
335 ni->library = nss_new_service (service_table ?: &default_table,
337 if (ni->library == NULL)
341 if (ni->library->lib_handle == NULL)
343 /* Load the shared library. */
344 size_t shlen = (7 + strlen (ni->name) + 3
345 + strlen (__nss_shlib_revision) + 1);
346 int saved_errno = errno;
347 char shlib_name[shlen];
349 /* Construct shared object name. */
350 __stpcpy (__stpcpy (__stpcpy (__stpcpy (shlib_name,
354 __nss_shlib_revision);
356 ni->library->lib_handle = __libc_dlopen (shlib_name);
357 if (ni->library->lib_handle == NULL)
359 /* Failed to load the library. */
360 ni->library->lib_handle = (void *) -1l;
361 __set_errno (saved_errno);
366 /* Call the init function when nscd is used. */
367 size_t initlen = (5 + strlen (ni->name)
368 + strlen ("_init") + 1);
369 char init_name[initlen];
371 /* Construct the init function name. */
372 __stpcpy (__stpcpy (__stpcpy (init_name,
377 /* Find the optional init function. */
378 void (*ifct) (void (*) (size_t, struct traced_file *))
379 = __libc_dlsym (ni->library->lib_handle, init_name);
382 void (*cb) (size_t, struct traced_file *) = nscd_init_cb;
398 __nss_lookup_function (service_user *ni, const char *fct_name)
400 void **found, *result;
402 /* We now modify global data. Protect it. */
403 __libc_lock_lock (lock);
405 /* Search the tree of functions previously requested. Data in the
406 tree are `known_function' structures, whose first member is a
407 `const char *', the lookup key. The search returns a pointer to
408 the tree node structure; the first member of the is a pointer to
409 our structure (i.e. what will be a `known_function'); since the
410 first member of that is the lookup key string, &FCT_NAME is close
411 enough to a pointer to our structure to use as a lookup key that
412 will be passed to `known_compare' (above). */
414 found = __tsearch (&fct_name, &ni->known, &known_compare);
416 /* This means out-of-memory. */
418 else if (*found != &fct_name)
420 /* The search found an existing structure in the tree. */
421 result = ((known_function *) *found)->fct_ptr;
423 PTR_DEMANGLE (result);
428 /* This name was not known before. Now we have a node in the tree
429 (in the proper sorted position for FCT_NAME) that points to
430 &FCT_NAME instead of any real `known_function' structure.
431 Allocate a new structure and fill it in. */
433 known_function *known = malloc (sizeof *known);
437 /* Oops. We can't instantiate this node properly.
438 Remove it from the tree. */
439 __tdelete (&fct_name, &ni->known, &known_compare);
445 /* Point the tree node at this new structure. */
447 known->fct_name = fct_name;
449 #if !defined DO_STATIC_NSS || defined SHARED
450 /* Load the appropriate library. */
451 if (nss_load_library (ni) != 0)
452 /* This only happens when out of memory. */
453 goto remove_from_tree;
455 if (ni->library->lib_handle == (void *) -1l)
456 /* Library not found => function not found. */
460 /* Get the desired function. */
461 size_t namlen = (5 + strlen (ni->name) + 1
462 + strlen (fct_name) + 1);
465 /* Construct the function name. */
466 __stpcpy (__stpcpy (__stpcpy (__stpcpy (name, "_nss_"),
471 /* Look up the symbol. */
472 result = __libc_dlsym (ni->library->lib_handle, name);
475 /* We can't get function address dynamically in static linking. */
477 # define DEFINE_ENT(h,nm) \
478 { #h"_get"#nm"ent_r", _nss_##h##_get##nm##ent_r }, \
479 { #h"_end"#nm"ent", _nss_##h##_end##nm##ent }, \
480 { #h"_set"#nm"ent", _nss_##h##_set##nm##ent },
481 # define DEFINE_GET(h,nm) \
482 { #h"_get"#nm"_r", _nss_##h##_get##nm##_r },
483 # define DEFINE_GETBY(h,nm,ky) \
484 { #h"_get"#nm"by"#ky"_r", _nss_##h##_get##nm##by##ky##_r },
485 static struct fct_tbl { const char *fname; void *fp; } *tp, tbl[] =
487 # include "function.def"
490 size_t namlen = (5 + strlen (ni->name) + 1
491 + strlen (fct_name) + 1);
494 /* Construct the function name. */
495 __stpcpy (__stpcpy (__stpcpy (name, ni->name),
500 for (tp = &tbl[0]; tp->fname; tp++)
501 if (strcmp (tp->fname, name) == 0)
509 /* Remember function pointer for later calls. Even if null, we
510 record it so a second try needn't search the library again. */
511 known->fct_ptr = result;
513 PTR_MANGLE (known->fct_ptr);
518 /* Remove the lock. */
519 __libc_lock_unlock (lock);
523 libc_hidden_def (__nss_lookup_function)
526 static name_database *
528 nss_parse_file (const char *fname)
531 name_database *result;
532 name_database_entry *last;
536 /* Open the configuration file. */
537 fp = fopen (fname, "rce");
541 /* No threads use this stream. */
542 __fsetlocking (fp, FSETLOCKING_BYCALLER);
544 result = (name_database *) malloc (sizeof (name_database));
551 result->entry = NULL;
552 result->library = NULL;
558 name_database_entry *this;
561 n = __getline (&line, &len, fp);
564 if (line[n - 1] == '\n')
567 /* Because the file format does not know any form of quoting we
568 can search forward for the next '#' character and if found
569 make it terminating the line. */
570 *__strchrnul (line, '#') = '\0';
572 /* If the line is blank it is ignored. */
576 /* Each line completely specifies the actions for a database. */
577 this = nss_getline (line);
583 result->entry = this;
588 while (!feof_unlocked (fp));
590 /* Free the buffer. */
592 /* Close configuration file. */
599 /* Read the source names:
600 `( <source> ( "[" "!"? (<status> "=" <action> )+ "]" )? )*'
602 static service_user *
604 nss_parse_service_list (const char *line)
606 service_user *result = NULL, **nextp = &result;
610 service_user *new_service;
613 while (isspace (line[0]))
616 /* No source specified. */
619 /* Read <source> identifier. */
621 while (line[0] != '\0' && !isspace (line[0]) && line[0] != '[')
627 new_service = (service_user *) malloc (sizeof (service_user)
628 + (line - name + 1));
629 if (new_service == NULL)
632 *((char *) __mempcpy (new_service->name, name, line - name)) = '\0';
634 /* Set default actions. */
635 new_service->actions[2 + NSS_STATUS_TRYAGAIN] = NSS_ACTION_CONTINUE;
636 new_service->actions[2 + NSS_STATUS_UNAVAIL] = NSS_ACTION_CONTINUE;
637 new_service->actions[2 + NSS_STATUS_NOTFOUND] = NSS_ACTION_CONTINUE;
638 new_service->actions[2 + NSS_STATUS_SUCCESS] = NSS_ACTION_RETURN;
639 new_service->actions[2 + NSS_STATUS_RETURN] = NSS_ACTION_RETURN;
640 new_service->library = NULL;
641 new_service->known = NULL;
642 new_service->next = NULL;
644 while (isspace (line[0]))
649 /* Read criterions. */
652 while (line[0] != '\0' && isspace (line[0]));
657 enum nss_status status;
658 lookup_actions action;
660 /* Grok ! before name to mean all statii but that one. */
661 not = line[0] == '!';
665 /* Read status name. */
667 while (line[0] != '\0' && !isspace (line[0]) && line[0] != '='
671 /* Compare with known statii. */
672 if (line - name == 7)
674 if (__strncasecmp (name, "SUCCESS", 7) == 0)
675 status = NSS_STATUS_SUCCESS;
676 else if (__strncasecmp (name, "UNAVAIL", 7) == 0)
677 status = NSS_STATUS_UNAVAIL;
681 else if (line - name == 8)
683 if (__strncasecmp (name, "NOTFOUND", 8) == 0)
684 status = NSS_STATUS_NOTFOUND;
685 else if (__strncasecmp (name, "TRYAGAIN", 8) == 0)
686 status = NSS_STATUS_TRYAGAIN;
693 while (isspace (line[0]))
699 while (isspace (line[0]));
702 while (line[0] != '\0' && !isspace (line[0]) && line[0] != '='
706 if (line - name == 6 && __strncasecmp (name, "RETURN", 6) == 0)
707 action = NSS_ACTION_RETURN;
708 else if (line - name == 8
709 && __strncasecmp (name, "CONTINUE", 8) == 0)
710 action = NSS_ACTION_CONTINUE;
716 /* Save the current action setting for this status,
717 set them all to the given action, and reset this one. */
718 const lookup_actions save = new_service->actions[2 + status];
719 new_service->actions[2 + NSS_STATUS_TRYAGAIN] = action;
720 new_service->actions[2 + NSS_STATUS_UNAVAIL] = action;
721 new_service->actions[2 + NSS_STATUS_NOTFOUND] = action;
722 new_service->actions[2 + NSS_STATUS_SUCCESS] = action;
723 new_service->actions[2 + status] = save;
726 new_service->actions[2 + status] = action;
728 /* Skip white spaces. */
729 while (isspace (line[0]))
732 while (line[0] != ']');
738 *nextp = new_service;
739 nextp = &new_service->next;
748 static name_database_entry *
750 nss_getline (char *line)
753 name_database_entry *result;
756 /* Ignore leading white spaces. ATTENTION: this is different from
757 what is implemented in Solaris. The Solaris man page says a line
758 beginning with a white space character is ignored. We regard
759 this as just another misfeature in Solaris. */
760 while (isspace (line[0]))
763 /* Recognize `<database> ":"'. */
765 while (line[0] != '\0' && !isspace (line[0]) && line[0] != ':')
767 if (line[0] == '\0' || name == line)
772 len = strlen (name) + 1;
774 result = (name_database_entry *) malloc (sizeof (name_database_entry) + len);
778 /* Save the database name. */
779 memcpy (result->name, name, len);
781 /* Parse the list of services. */
782 result->service = nss_parse_service_list (line);
789 #if !defined DO_STATIC_NSS || defined SHARED
790 static service_library *
792 nss_new_service (name_database *database, const char *name)
794 service_library **currentp = &database->library;
796 while (*currentp != NULL)
798 if (strcmp ((*currentp)->name, name) == 0)
800 currentp = &(*currentp)->next;
803 /* We have to add the new service. */
804 *currentp = (service_library *) malloc (sizeof (service_library));
805 if (*currentp == NULL)
808 (*currentp)->name = name;
809 (*currentp)->lib_handle = NULL;
810 (*currentp)->next = NULL;
817 #if defined SHARED && defined USE_NSCD
818 /* Load all libraries for the service. */
820 nss_load_all_libraries (const char *service, const char *def)
822 service_user *ni = NULL;
824 if (__nss_database_lookup (service, NULL, def, &ni) == 0)
827 nss_load_library (ni);
833 /* Called by nscd and nscd alone. */
835 __nss_disable_nscd (void (*cb) (size_t, struct traced_file *))
843 /* Find all the relevant modules so that the init functions are called. */
844 nss_load_all_libraries ("passwd", "compat [NOTFOUND=return] files");
845 nss_load_all_libraries ("group", "compat [NOTFOUND=return] files");
846 nss_load_all_libraries ("hosts", "dns [!UNAVAIL=return] files");
847 nss_load_all_libraries ("services", NULL);
849 /* Disable all uses of NSCD. */
850 __nss_not_use_nscd_passwd = -1;
851 __nss_not_use_nscd_group = -1;
852 __nss_not_use_nscd_hosts = -1;
853 __nss_not_use_nscd_services = -1;
854 __nss_not_use_nscd_netgroup = -1;
859 free_database_entries (name_database_entry *entry)
861 while (entry != NULL)
863 name_database_entry *olde = entry;
864 service_user *service = entry->service;
866 while (service != NULL)
868 service_user *olds = service;
870 if (service->known != NULL)
871 __tdestroy (service->known, free);
873 service = service->next;
882 /* Free all resources if necessary. */
883 libc_freeres_fn (free_defconfig)
885 name_database_entry *entry = defconfig_entries;
888 /* defconfig was not used. */
891 /* Don't disturb ongoing other threads (if there are any). */
892 defconfig_entries = NULL;
894 free_database_entries (entry);
897 libc_freeres_fn (free_mem)
899 name_database *top = service_table;
900 service_library *library;
903 /* Maybe we have not read the nsswitch.conf file. */
906 /* Don't disturb ongoing other threads (if there are any). */
907 service_table = NULL;
909 free_database_entries (top->entry);
911 library = top->library;
912 while (library != NULL)
914 service_library *oldl = library;
916 if (library->lib_handle && library->lib_handle != (void *) -1l)
917 __libc_dlclose (library->lib_handle);
919 library = library->next;