1 /* Copyright (C) 1996-2017 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 <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
);
46 static name_database_entry
*nss_getline (char *line
);
47 static service_user
*nss_parse_service_list (const char *line
);
48 #if !defined DO_STATIC_NSS || defined SHARED
49 static service_library
*nss_new_service (name_database
*database
,
54 /* Declare external database variables. */
55 #define DEFINE_DATABASE(name) \
56 extern service_user *__nss_##name##_database attribute_hidden; \
57 weak_extern (__nss_##name##_database)
58 #include "databases.def"
59 #undef DEFINE_DATABASE
61 /* Structure to map database name to variable. */
68 #define DEFINE_DATABASE(name) \
69 { #name, &__nss_##name##_database },
70 #include "databases.def"
71 #undef DEFINE_DATABASE
73 #define ndatabases (sizeof (databases) / sizeof (databases[0]))
76 /* Flags whether custom rules for database is set. */
77 bool __nss_database_custom
[NSS_DBSIDX_max
];
81 __libc_lock_define_initialized (static, lock
)
83 #if !defined DO_STATIC_NSS || defined SHARED
84 /* String with revision number of the shared object files. */
85 static const char *const __nss_shlib_revision
= LIBNSS_FILES_SO
+ 15;
88 /* The root of the whole data base. */
89 static name_database
*service_table
;
91 /* List of default service lists that were generated by glibc because
92 /etc/nsswitch.conf did not provide a value.
93 The list is only maintained so we can free such service lists in
95 static name_database_entry
*defconfig_entries
;
98 #if defined USE_NSCD && (!defined DO_STATIC_NSS || defined SHARED)
99 /* Nonzero if this is the nscd process. */
101 /* The callback passed to the init functions when nscd is used. */
102 static void (*nscd_init_cb
) (size_t, struct traced_file
*);
106 /* -1 == database not found
107 0 == database entry pointer stored */
109 __nss_database_lookup (const char *database
, const char *alternate_name
,
110 const char *defconfig
, service_user
**ni
)
112 /* Prevent multiple threads to change the service table. */
113 __libc_lock_lock (lock
);
115 /* Reconsider database variable in case some other thread called
116 `__nss_configure_lookup' while we waited for the lock. */
119 __libc_lock_unlock (lock
);
123 /* Are we initialized yet? */
124 if (service_table
== NULL
)
125 /* Read config file. */
126 service_table
= nss_parse_file (_PATH_NSSWITCH_CONF
);
128 /* Test whether configuration data is available. */
129 if (service_table
!= NULL
)
131 /* Return first `service_user' entry for DATABASE. */
132 name_database_entry
*entry
;
134 /* XXX Could use some faster mechanism here. But each database is
135 only requested once and so this might not be critical. */
136 for (entry
= service_table
->entry
; entry
!= NULL
; entry
= entry
->next
)
137 if (strcmp (database
, entry
->name
) == 0)
138 *ni
= entry
->service
;
140 if (*ni
== NULL
&& alternate_name
!= NULL
)
141 /* We haven't found an entry so far. Try to find it with the
143 for (entry
= service_table
->entry
; entry
!= NULL
; entry
= entry
->next
)
144 if (strcmp (alternate_name
, entry
->name
) == 0)
145 *ni
= entry
->service
;
148 /* No configuration data is available, either because nsswitch.conf
149 doesn't exist or because it doesn't have a line for this database.
151 DEFCONFIG specifies the default service list for this database,
152 or null to use the most common default. */
155 *ni
= nss_parse_service_list (defconfig
156 ?: "nis [NOTFOUND=return] files");
159 /* Record the memory we've just allocated in defconfig_entries list,
160 so we can free it later. */
161 name_database_entry
*entry
;
163 /* Allocate ENTRY plus size of name (1 here). */
164 entry
= (name_database_entry
*) malloc (sizeof (*entry
) + 1);
168 entry
->next
= defconfig_entries
;
169 entry
->service
= *ni
;
170 entry
->name
[0] = '\0';
171 defconfig_entries
= entry
;
176 __libc_lock_unlock (lock
);
178 return *ni
!= NULL
? 0 : -1;
180 libc_hidden_def (__nss_database_lookup
)
187 __nss_lookup (service_user
**ni
, const char *fct_name
, const char *fct2_name
,
190 *fctp
= __nss_lookup_function (*ni
, fct_name
);
191 if (*fctp
== NULL
&& fct2_name
!= NULL
)
192 *fctp
= __nss_lookup_function (*ni
, fct2_name
);
195 && nss_next_action (*ni
, NSS_STATUS_UNAVAIL
) == NSS_ACTION_CONTINUE
196 && (*ni
)->next
!= NULL
)
200 *fctp
= __nss_lookup_function (*ni
, fct_name
);
201 if (*fctp
== NULL
&& fct2_name
!= NULL
)
202 *fctp
= __nss_lookup_function (*ni
, fct2_name
);
205 return *fctp
!= NULL
? 0 : (*ni
)->next
== NULL
? 1 : -1;
207 libc_hidden_def (__nss_lookup
)
211 0 == adjusted for next function
214 __nss_next2 (service_user
**ni
, const char *fct_name
, const char *fct2_name
,
215 void **fctp
, int status
, int all_values
)
219 if (nss_next_action (*ni
, NSS_STATUS_TRYAGAIN
) == NSS_ACTION_RETURN
220 && nss_next_action (*ni
, NSS_STATUS_UNAVAIL
) == NSS_ACTION_RETURN
221 && nss_next_action (*ni
, NSS_STATUS_NOTFOUND
) == NSS_ACTION_RETURN
222 && nss_next_action (*ni
, NSS_STATUS_SUCCESS
) == NSS_ACTION_RETURN
)
227 /* This is really only for debugging. */
228 if (__builtin_expect (NSS_STATUS_TRYAGAIN
> status
229 || status
> NSS_STATUS_RETURN
, 0))
230 __libc_fatal ("illegal status in __nss_next");
232 if (nss_next_action (*ni
, status
) == NSS_ACTION_RETURN
)
236 if ((*ni
)->next
== NULL
)
243 *fctp
= __nss_lookup_function (*ni
, fct_name
);
244 if (*fctp
== NULL
&& fct2_name
!= NULL
)
245 *fctp
= __nss_lookup_function (*ni
, fct2_name
);
248 && nss_next_action (*ni
, NSS_STATUS_UNAVAIL
) == NSS_ACTION_CONTINUE
249 && (*ni
)->next
!= NULL
);
251 return *fctp
!= NULL
? 0 : -1;
253 libc_hidden_def (__nss_next2
)
257 attribute_compat_text_section
258 __nss_next (service_user
**ni
, const char *fct_name
, void **fctp
, int status
,
261 return __nss_next2 (ni
, fct_name
, NULL
, fctp
, status
, all_values
);
266 __nss_configure_lookup (const char *dbname
, const char *service_line
)
268 service_user
*new_db
;
271 for (cnt
= 0; cnt
< ndatabases
; ++cnt
)
273 int cmp
= strcmp (dbname
, databases
[cnt
].name
);
278 __set_errno (EINVAL
);
283 if (cnt
== ndatabases
)
285 __set_errno (EINVAL
);
289 /* Test whether it is really used. */
290 if (databases
[cnt
].dbp
== NULL
)
291 /* Nothing to do, but we could do. */
294 /* Try to generate new data. */
295 new_db
= nss_parse_service_list (service_line
);
298 /* Illegal service specification. */
299 __set_errno (EINVAL
);
303 /* Prevent multiple threads to change the service table. */
304 __libc_lock_lock (lock
);
306 /* Install new rules. */
307 *databases
[cnt
].dbp
= new_db
;
309 __nss_database_custom
[cnt
] = true;
312 __libc_lock_unlock (lock
);
318 /* Comparison function for searching NI->known tree. */
320 known_compare (const void *p1
, const void *p2
)
322 return p1
== p2
? 0 : strcmp (*(const char *const *) p1
,
323 *(const char *const *) p2
);
327 #if !defined DO_STATIC_NSS || defined SHARED
330 nss_load_library (service_user
*ni
)
332 if (ni
->library
== NULL
)
334 /* This service has not yet been used. Fetch the service
335 library for it, creating a new one if need be. If there
336 is no service table from the file, this static variable
337 holds the head of the service_library list made from the
338 default configuration. */
339 static name_database default_table
;
340 ni
->library
= nss_new_service (service_table
?: &default_table
,
342 if (ni
->library
== NULL
)
346 if (ni
->library
->lib_handle
== NULL
)
348 /* Load the shared library. */
349 size_t shlen
= (7 + strlen (ni
->name
) + 3
350 + strlen (__nss_shlib_revision
) + 1);
351 int saved_errno
= errno
;
352 char shlib_name
[shlen
];
354 /* Construct shared object name. */
355 __stpcpy (__stpcpy (__stpcpy (__stpcpy (shlib_name
,
359 __nss_shlib_revision
);
361 ni
->library
->lib_handle
= __libc_dlopen (shlib_name
);
362 if (ni
->library
->lib_handle
== NULL
)
364 /* Failed to load the library. */
365 ni
->library
->lib_handle
= (void *) -1l;
366 __set_errno (saved_errno
);
371 /* Call the init function when nscd is used. */
372 size_t initlen
= (5 + strlen (ni
->name
)
373 + strlen ("_init") + 1);
374 char init_name
[initlen
];
376 /* Construct the init function name. */
377 __stpcpy (__stpcpy (__stpcpy (init_name
,
382 /* Find the optional init function. */
383 void (*ifct
) (void (*) (size_t, struct traced_file
*))
384 = __libc_dlsym (ni
->library
->lib_handle
, init_name
);
387 void (*cb
) (size_t, struct traced_file
*) = nscd_init_cb
;
403 __nss_lookup_function (service_user
*ni
, const char *fct_name
)
405 void **found
, *result
;
407 /* We now modify global data. Protect it. */
408 __libc_lock_lock (lock
);
410 /* Search the tree of functions previously requested. Data in the
411 tree are `known_function' structures, whose first member is a
412 `const char *', the lookup key. The search returns a pointer to
413 the tree node structure; the first member of the is a pointer to
414 our structure (i.e. what will be a `known_function'); since the
415 first member of that is the lookup key string, &FCT_NAME is close
416 enough to a pointer to our structure to use as a lookup key that
417 will be passed to `known_compare' (above). */
419 found
= __tsearch (&fct_name
, &ni
->known
, &known_compare
);
421 /* This means out-of-memory. */
423 else if (*found
!= &fct_name
)
425 /* The search found an existing structure in the tree. */
426 result
= ((known_function
*) *found
)->fct_ptr
;
428 PTR_DEMANGLE (result
);
433 /* This name was not known before. Now we have a node in the tree
434 (in the proper sorted position for FCT_NAME) that points to
435 &FCT_NAME instead of any real `known_function' structure.
436 Allocate a new structure and fill it in. */
438 known_function
*known
= malloc (sizeof *known
);
441 #if !defined DO_STATIC_NSS || defined SHARED
444 /* Oops. We can't instantiate this node properly.
445 Remove it from the tree. */
446 __tdelete (&fct_name
, &ni
->known
, &known_compare
);
452 /* Point the tree node at this new structure. */
454 known
->fct_name
= fct_name
;
456 #if !defined DO_STATIC_NSS || defined SHARED
457 /* Load the appropriate library. */
458 if (nss_load_library (ni
) != 0)
459 /* This only happens when out of memory. */
460 goto remove_from_tree
;
462 if (ni
->library
->lib_handle
== (void *) -1l)
463 /* Library not found => function not found. */
467 /* Get the desired function. */
468 size_t namlen
= (5 + strlen (ni
->name
) + 1
469 + strlen (fct_name
) + 1);
472 /* Construct the function name. */
473 __stpcpy (__stpcpy (__stpcpy (__stpcpy (name
, "_nss_"),
478 /* Look up the symbol. */
479 result
= __libc_dlsym (ni
->library
->lib_handle
, name
);
482 /* We can't get function address dynamically in static linking. */
484 # define DEFINE_ENT(h,nm) \
485 { #h"_get"#nm"ent_r", _nss_##h##_get##nm##ent_r }, \
486 { #h"_end"#nm"ent", _nss_##h##_end##nm##ent }, \
487 { #h"_set"#nm"ent", _nss_##h##_set##nm##ent },
488 # define DEFINE_GET(h,nm) \
489 { #h"_get"#nm"_r", _nss_##h##_get##nm##_r },
490 # define DEFINE_GETBY(h,nm,ky) \
491 { #h"_get"#nm"by"#ky"_r", _nss_##h##_get##nm##by##ky##_r },
492 static struct fct_tbl
{ const char *fname
; void *fp
; } *tp
, tbl
[] =
494 # include "function.def"
497 size_t namlen
= (5 + strlen (ni
->name
) + 1
498 + strlen (fct_name
) + 1);
501 /* Construct the function name. */
502 __stpcpy (__stpcpy (__stpcpy (name
, ni
->name
),
507 for (tp
= &tbl
[0]; tp
->fname
; tp
++)
508 if (strcmp (tp
->fname
, name
) == 0)
516 /* Remember function pointer for later calls. Even if null, we
517 record it so a second try needn't search the library again. */
518 known
->fct_ptr
= result
;
520 PTR_MANGLE (known
->fct_ptr
);
525 /* Remove the lock. */
526 __libc_lock_unlock (lock
);
530 libc_hidden_def (__nss_lookup_function
)
533 static name_database
*
534 nss_parse_file (const char *fname
)
537 name_database
*result
;
538 name_database_entry
*last
;
542 /* Open the configuration file. */
543 fp
= fopen (fname
, "rce");
547 /* No threads use this stream. */
548 __fsetlocking (fp
, FSETLOCKING_BYCALLER
);
550 result
= (name_database
*) malloc (sizeof (name_database
));
557 result
->entry
= NULL
;
558 result
->library
= NULL
;
564 name_database_entry
*this;
567 n
= __getline (&line
, &len
, fp
);
570 if (line
[n
- 1] == '\n')
573 /* Because the file format does not know any form of quoting we
574 can search forward for the next '#' character and if found
575 make it terminating the line. */
576 *__strchrnul (line
, '#') = '\0';
578 /* If the line is blank it is ignored. */
582 /* Each line completely specifies the actions for a database. */
583 this = nss_getline (line
);
589 result
->entry
= this;
594 while (!feof_unlocked (fp
));
596 /* Free the buffer. */
598 /* Close configuration file. */
605 /* Read the source names:
606 `( <source> ( "[" "!"? (<status> "=" <action> )+ "]" )? )*'
608 static service_user
*
609 nss_parse_service_list (const char *line
)
611 service_user
*result
= NULL
, **nextp
= &result
;
615 service_user
*new_service
;
618 while (isspace (line
[0]))
621 /* No source specified. */
624 /* Read <source> identifier. */
626 while (line
[0] != '\0' && !isspace (line
[0]) && line
[0] != '[')
632 new_service
= (service_user
*) malloc (sizeof (service_user
)
633 + (line
- name
+ 1));
634 if (new_service
== NULL
)
637 *((char *) __mempcpy (new_service
->name
, name
, line
- name
)) = '\0';
639 /* Set default actions. */
640 new_service
->actions
[2 + NSS_STATUS_TRYAGAIN
] = NSS_ACTION_CONTINUE
;
641 new_service
->actions
[2 + NSS_STATUS_UNAVAIL
] = NSS_ACTION_CONTINUE
;
642 new_service
->actions
[2 + NSS_STATUS_NOTFOUND
] = NSS_ACTION_CONTINUE
;
643 new_service
->actions
[2 + NSS_STATUS_SUCCESS
] = NSS_ACTION_RETURN
;
644 new_service
->actions
[2 + NSS_STATUS_RETURN
] = NSS_ACTION_RETURN
;
645 new_service
->library
= NULL
;
646 new_service
->known
= NULL
;
647 new_service
->next
= NULL
;
649 while (isspace (line
[0]))
654 /* Read criterions. */
657 while (line
[0] != '\0' && isspace (line
[0]));
662 enum nss_status status
;
663 lookup_actions action
;
665 /* Grok ! before name to mean all statii but that one. */
666 not = line
[0] == '!';
670 /* Read status name. */
672 while (line
[0] != '\0' && !isspace (line
[0]) && line
[0] != '='
676 /* Compare with known statii. */
677 if (line
- name
== 7)
679 if (__strncasecmp (name
, "SUCCESS", 7) == 0)
680 status
= NSS_STATUS_SUCCESS
;
681 else if (__strncasecmp (name
, "UNAVAIL", 7) == 0)
682 status
= NSS_STATUS_UNAVAIL
;
686 else if (line
- name
== 8)
688 if (__strncasecmp (name
, "NOTFOUND", 8) == 0)
689 status
= NSS_STATUS_NOTFOUND
;
690 else if (__strncasecmp (name
, "TRYAGAIN", 8) == 0)
691 status
= NSS_STATUS_TRYAGAIN
;
698 while (isspace (line
[0]))
704 while (isspace (line
[0]));
707 while (line
[0] != '\0' && !isspace (line
[0]) && line
[0] != '='
711 if (line
- name
== 6 && __strncasecmp (name
, "RETURN", 6) == 0)
712 action
= NSS_ACTION_RETURN
;
713 else if (line
- name
== 8
714 && __strncasecmp (name
, "CONTINUE", 8) == 0)
715 action
= NSS_ACTION_CONTINUE
;
716 else if (line
- name
== 5
717 && __strncasecmp (name
, "MERGE", 5) == 0)
718 action
= NSS_ACTION_MERGE
;
724 /* Save the current action setting for this status,
725 set them all to the given action, and reset this one. */
726 const lookup_actions save
= new_service
->actions
[2 + status
];
727 new_service
->actions
[2 + NSS_STATUS_TRYAGAIN
] = action
;
728 new_service
->actions
[2 + NSS_STATUS_UNAVAIL
] = action
;
729 new_service
->actions
[2 + NSS_STATUS_NOTFOUND
] = action
;
730 new_service
->actions
[2 + NSS_STATUS_SUCCESS
] = action
;
731 new_service
->actions
[2 + status
] = save
;
734 new_service
->actions
[2 + status
] = action
;
736 /* Skip white spaces. */
737 while (isspace (line
[0]))
740 while (line
[0] != ']');
746 *nextp
= new_service
;
747 nextp
= &new_service
->next
;
756 static name_database_entry
*
757 nss_getline (char *line
)
760 name_database_entry
*result
;
763 /* Ignore leading white spaces. ATTENTION: this is different from
764 what is implemented in Solaris. The Solaris man page says a line
765 beginning with a white space character is ignored. We regard
766 this as just another misfeature in Solaris. */
767 while (isspace (line
[0]))
770 /* Recognize `<database> ":"'. */
772 while (line
[0] != '\0' && !isspace (line
[0]) && line
[0] != ':')
774 if (line
[0] == '\0' || name
== line
)
779 len
= strlen (name
) + 1;
781 result
= (name_database_entry
*) malloc (sizeof (name_database_entry
) + len
);
785 /* Save the database name. */
786 memcpy (result
->name
, name
, len
);
788 /* Parse the list of services. */
789 result
->service
= nss_parse_service_list (line
);
796 #if !defined DO_STATIC_NSS || defined SHARED
797 static service_library
*
798 nss_new_service (name_database
*database
, const char *name
)
800 service_library
**currentp
= &database
->library
;
802 while (*currentp
!= NULL
)
804 if (strcmp ((*currentp
)->name
, name
) == 0)
806 currentp
= &(*currentp
)->next
;
809 /* We have to add the new service. */
810 *currentp
= (service_library
*) malloc (sizeof (service_library
));
811 if (*currentp
== NULL
)
814 (*currentp
)->name
= name
;
815 (*currentp
)->lib_handle
= NULL
;
816 (*currentp
)->next
= NULL
;
823 #if defined SHARED && defined USE_NSCD
824 /* Load all libraries for the service. */
826 nss_load_all_libraries (const char *service
, const char *def
)
828 service_user
*ni
= NULL
;
830 if (__nss_database_lookup (service
, NULL
, def
, &ni
) == 0)
833 nss_load_library (ni
);
839 /* Called by nscd and nscd alone. */
841 __nss_disable_nscd (void (*cb
) (size_t, struct traced_file
*))
849 /* Find all the relevant modules so that the init functions are called. */
850 nss_load_all_libraries ("passwd", "compat [NOTFOUND=return] files");
851 nss_load_all_libraries ("group", "compat [NOTFOUND=return] files");
852 nss_load_all_libraries ("hosts", "dns [!UNAVAIL=return] files");
853 nss_load_all_libraries ("services", NULL
);
855 /* Disable all uses of NSCD. */
856 __nss_not_use_nscd_passwd
= -1;
857 __nss_not_use_nscd_group
= -1;
858 __nss_not_use_nscd_hosts
= -1;
859 __nss_not_use_nscd_services
= -1;
860 __nss_not_use_nscd_netgroup
= -1;
865 free_database_entries (name_database_entry
*entry
)
867 while (entry
!= NULL
)
869 name_database_entry
*olde
= entry
;
870 service_user
*service
= entry
->service
;
872 while (service
!= NULL
)
874 service_user
*olds
= service
;
876 if (service
->known
!= NULL
)
877 __tdestroy (service
->known
, free
);
879 service
= service
->next
;
888 /* Free all resources if necessary. */
889 libc_freeres_fn (free_defconfig
)
891 name_database_entry
*entry
= defconfig_entries
;
894 /* defconfig was not used. */
897 /* Don't disturb ongoing other threads (if there are any). */
898 defconfig_entries
= NULL
;
900 free_database_entries (entry
);
903 libc_freeres_fn (free_mem
)
905 name_database
*top
= service_table
;
906 service_library
*library
;
909 /* Maybe we have not read the nsswitch.conf file. */
912 /* Don't disturb ongoing other threads (if there are any). */
913 service_table
= NULL
;
915 free_database_entries (top
->entry
);
917 library
= top
->library
;
918 while (library
!= NULL
)
920 service_library
*oldl
= library
;
922 if (library
->lib_handle
&& library
->lib_handle
!= (void *) -1l)
923 __libc_dlclose (library
->lib_handle
);
925 library
= library
->next
;