1 /* Copyright (C) 1996-2018 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"
45 #ifdef LINK_OBSOLETE_NSL
46 # define DEFAULT_CONFIG "compat [NOTFOUND=return] files"
47 # define DEFAULT_DEFCONFIG "nis [NOTFOUND=return] files"
49 # define DEFAULT_CONFIG "files"
50 # define DEFAULT_DEFCONFIG "files"
53 /* Prototypes for the local functions. */
54 static name_database
*nss_parse_file (const char *fname
);
55 static name_database_entry
*nss_getline (char *line
);
56 static service_user
*nss_parse_service_list (const char *line
);
57 #if !defined DO_STATIC_NSS || defined SHARED
58 static service_library
*nss_new_service (name_database
*database
,
63 /* Declare external database variables. */
64 #define DEFINE_DATABASE(name) \
65 extern service_user *__nss_##name##_database attribute_hidden; \
66 weak_extern (__nss_##name##_database)
67 #include "databases.def"
68 #undef DEFINE_DATABASE
70 /* Structure to map database name to variable. */
77 #define DEFINE_DATABASE(name) \
78 { #name, &__nss_##name##_database },
79 #include "databases.def"
80 #undef DEFINE_DATABASE
82 #define ndatabases (sizeof (databases) / sizeof (databases[0]))
85 /* Flags whether custom rules for database is set. */
86 bool __nss_database_custom
[NSS_DBSIDX_max
];
90 __libc_lock_define_initialized (static, lock
)
92 #if !defined DO_STATIC_NSS || defined SHARED
93 /* String with revision number of the shared object files. */
94 static const char *const __nss_shlib_revision
= LIBNSS_FILES_SO
+ 15;
97 /* The root of the whole data base. */
98 static name_database
*service_table
;
100 /* List of default service lists that were generated by glibc because
101 /etc/nsswitch.conf did not provide a value.
102 The list is only maintained so we can free such service lists in
104 static name_database_entry
*defconfig_entries
;
107 #if defined USE_NSCD && (!defined DO_STATIC_NSS || defined SHARED)
108 /* Nonzero if this is the nscd process. */
110 /* The callback passed to the init functions when nscd is used. */
111 static void (*nscd_init_cb
) (size_t, struct traced_file
*);
115 /* -1 == database not found
116 0 == database entry pointer stored */
118 __nss_database_lookup (const char *database
, const char *alternate_name
,
119 const char *defconfig
, service_user
**ni
)
121 /* Prevent multiple threads to change the service table. */
122 __libc_lock_lock (lock
);
124 /* Reconsider database variable in case some other thread called
125 `__nss_configure_lookup' while we waited for the lock. */
128 __libc_lock_unlock (lock
);
132 /* Are we initialized yet? */
133 if (service_table
== NULL
)
134 /* Read config file. */
135 service_table
= nss_parse_file (_PATH_NSSWITCH_CONF
);
137 /* Test whether configuration data is available. */
138 if (service_table
!= NULL
)
140 /* Return first `service_user' entry for DATABASE. */
141 name_database_entry
*entry
;
143 /* XXX Could use some faster mechanism here. But each database is
144 only requested once and so this might not be critical. */
145 for (entry
= service_table
->entry
; entry
!= NULL
; entry
= entry
->next
)
146 if (strcmp (database
, entry
->name
) == 0)
147 *ni
= entry
->service
;
149 if (*ni
== NULL
&& alternate_name
!= NULL
)
150 /* We haven't found an entry so far. Try to find it with the
152 for (entry
= service_table
->entry
; entry
!= NULL
; entry
= entry
->next
)
153 if (strcmp (alternate_name
, entry
->name
) == 0)
154 *ni
= entry
->service
;
157 /* No configuration data is available, either because nsswitch.conf
158 doesn't exist or because it doesn't have a line for this database.
160 DEFCONFIG specifies the default service list for this database,
161 or null to use the most common default. */
164 *ni
= nss_parse_service_list (defconfig
?: DEFAULT_DEFCONFIG
);
167 /* Record the memory we've just allocated in defconfig_entries list,
168 so we can free it later. */
169 name_database_entry
*entry
;
171 /* Allocate ENTRY plus size of name (1 here). */
172 entry
= (name_database_entry
*) malloc (sizeof (*entry
) + 1);
176 entry
->next
= defconfig_entries
;
177 entry
->service
= *ni
;
178 entry
->name
[0] = '\0';
179 defconfig_entries
= entry
;
184 __libc_lock_unlock (lock
);
186 return *ni
!= NULL
? 0 : -1;
188 libc_hidden_def (__nss_database_lookup
)
195 __nss_lookup (service_user
**ni
, const char *fct_name
, const char *fct2_name
,
198 *fctp
= __nss_lookup_function (*ni
, fct_name
);
199 if (*fctp
== NULL
&& fct2_name
!= NULL
)
200 *fctp
= __nss_lookup_function (*ni
, fct2_name
);
203 && nss_next_action (*ni
, NSS_STATUS_UNAVAIL
) == NSS_ACTION_CONTINUE
204 && (*ni
)->next
!= NULL
)
208 *fctp
= __nss_lookup_function (*ni
, fct_name
);
209 if (*fctp
== NULL
&& fct2_name
!= NULL
)
210 *fctp
= __nss_lookup_function (*ni
, fct2_name
);
213 return *fctp
!= NULL
? 0 : (*ni
)->next
== NULL
? 1 : -1;
215 libc_hidden_def (__nss_lookup
)
219 0 == adjusted for next function
222 __nss_next2 (service_user
**ni
, const char *fct_name
, const char *fct2_name
,
223 void **fctp
, int status
, int all_values
)
227 if (nss_next_action (*ni
, NSS_STATUS_TRYAGAIN
) == NSS_ACTION_RETURN
228 && nss_next_action (*ni
, NSS_STATUS_UNAVAIL
) == NSS_ACTION_RETURN
229 && nss_next_action (*ni
, NSS_STATUS_NOTFOUND
) == NSS_ACTION_RETURN
230 && nss_next_action (*ni
, NSS_STATUS_SUCCESS
) == NSS_ACTION_RETURN
)
235 /* This is really only for debugging. */
236 if (__builtin_expect (NSS_STATUS_TRYAGAIN
> status
237 || status
> NSS_STATUS_RETURN
, 0))
238 __libc_fatal ("illegal status in __nss_next");
240 if (nss_next_action (*ni
, status
) == NSS_ACTION_RETURN
)
244 if ((*ni
)->next
== NULL
)
251 *fctp
= __nss_lookup_function (*ni
, fct_name
);
252 if (*fctp
== NULL
&& fct2_name
!= NULL
)
253 *fctp
= __nss_lookup_function (*ni
, fct2_name
);
256 && nss_next_action (*ni
, NSS_STATUS_UNAVAIL
) == NSS_ACTION_CONTINUE
257 && (*ni
)->next
!= NULL
);
259 return *fctp
!= NULL
? 0 : -1;
261 libc_hidden_def (__nss_next2
)
265 attribute_compat_text_section
266 __nss_next (service_user
**ni
, const char *fct_name
, void **fctp
, int status
,
269 return __nss_next2 (ni
, fct_name
, NULL
, fctp
, status
, all_values
);
274 __nss_configure_lookup (const char *dbname
, const char *service_line
)
276 service_user
*new_db
;
279 for (cnt
= 0; cnt
< ndatabases
; ++cnt
)
281 int cmp
= strcmp (dbname
, databases
[cnt
].name
);
286 __set_errno (EINVAL
);
291 if (cnt
== ndatabases
)
293 __set_errno (EINVAL
);
297 /* Test whether it is really used. */
298 if (databases
[cnt
].dbp
== NULL
)
299 /* Nothing to do, but we could do. */
302 /* Try to generate new data. */
303 new_db
= nss_parse_service_list (service_line
);
306 /* Illegal service specification. */
307 __set_errno (EINVAL
);
311 /* Prevent multiple threads to change the service table. */
312 __libc_lock_lock (lock
);
314 /* Install new rules. */
315 *databases
[cnt
].dbp
= new_db
;
317 __nss_database_custom
[cnt
] = true;
320 __libc_lock_unlock (lock
);
326 /* Comparison function for searching NI->known tree. */
328 known_compare (const void *p1
, const void *p2
)
330 return p1
== p2
? 0 : strcmp (*(const char *const *) p1
,
331 *(const char *const *) p2
);
335 #if !defined DO_STATIC_NSS || defined SHARED
338 nss_load_library (service_user
*ni
)
340 if (ni
->library
== NULL
)
342 /* This service has not yet been used. Fetch the service
343 library for it, creating a new one if need be. If there
344 is no service table from the file, this static variable
345 holds the head of the service_library list made from the
346 default configuration. */
347 static name_database default_table
;
348 ni
->library
= nss_new_service (service_table
?: &default_table
,
350 if (ni
->library
== NULL
)
354 if (ni
->library
->lib_handle
== NULL
)
356 /* Load the shared library. */
357 size_t shlen
= (7 + strlen (ni
->name
) + 3
358 + strlen (__nss_shlib_revision
) + 1);
359 int saved_errno
= errno
;
360 char shlib_name
[shlen
];
362 /* Construct shared object name. */
363 __stpcpy (__stpcpy (__stpcpy (__stpcpy (shlib_name
,
367 __nss_shlib_revision
);
369 ni
->library
->lib_handle
= __libc_dlopen (shlib_name
);
370 if (ni
->library
->lib_handle
== NULL
)
372 /* Failed to load the library. */
373 ni
->library
->lib_handle
= (void *) -1l;
374 __set_errno (saved_errno
);
379 /* Call the init function when nscd is used. */
380 size_t initlen
= (5 + strlen (ni
->name
)
381 + strlen ("_init") + 1);
382 char init_name
[initlen
];
384 /* Construct the init function name. */
385 __stpcpy (__stpcpy (__stpcpy (init_name
,
390 /* Find the optional init function. */
391 void (*ifct
) (void (*) (size_t, struct traced_file
*))
392 = __libc_dlsym (ni
->library
->lib_handle
, init_name
);
395 void (*cb
) (size_t, struct traced_file
*) = nscd_init_cb
;
411 __nss_lookup_function (service_user
*ni
, const char *fct_name
)
413 void **found
, *result
;
415 /* We now modify global data. Protect it. */
416 __libc_lock_lock (lock
);
418 /* Search the tree of functions previously requested. Data in the
419 tree are `known_function' structures, whose first member is a
420 `const char *', the lookup key. The search returns a pointer to
421 the tree node structure; the first member of the is a pointer to
422 our structure (i.e. what will be a `known_function'); since the
423 first member of that is the lookup key string, &FCT_NAME is close
424 enough to a pointer to our structure to use as a lookup key that
425 will be passed to `known_compare' (above). */
427 found
= __tsearch (&fct_name
, &ni
->known
, &known_compare
);
429 /* This means out-of-memory. */
431 else if (*found
!= &fct_name
)
433 /* The search found an existing structure in the tree. */
434 result
= ((known_function
*) *found
)->fct_ptr
;
436 PTR_DEMANGLE (result
);
441 /* This name was not known before. Now we have a node in the tree
442 (in the proper sorted position for FCT_NAME) that points to
443 &FCT_NAME instead of any real `known_function' structure.
444 Allocate a new structure and fill it in. */
446 known_function
*known
= malloc (sizeof *known
);
449 #if !defined DO_STATIC_NSS || defined SHARED
452 /* Oops. We can't instantiate this node properly.
453 Remove it from the tree. */
454 __tdelete (&fct_name
, &ni
->known
, &known_compare
);
460 /* Point the tree node at this new structure. */
462 known
->fct_name
= fct_name
;
464 #if !defined DO_STATIC_NSS || defined SHARED
465 /* Load the appropriate library. */
466 if (nss_load_library (ni
) != 0)
467 /* This only happens when out of memory. */
468 goto remove_from_tree
;
470 if (ni
->library
->lib_handle
== (void *) -1l)
471 /* Library not found => function not found. */
475 /* Get the desired function. */
476 size_t namlen
= (5 + strlen (ni
->name
) + 1
477 + strlen (fct_name
) + 1);
480 /* Construct the function name. */
481 __stpcpy (__stpcpy (__stpcpy (__stpcpy (name
, "_nss_"),
486 /* Look up the symbol. */
487 result
= __libc_dlsym (ni
->library
->lib_handle
, name
);
490 /* We can't get function address dynamically in static linking. */
492 # define DEFINE_ENT(h,nm) \
493 { #h"_get"#nm"ent_r", _nss_##h##_get##nm##ent_r }, \
494 { #h"_end"#nm"ent", _nss_##h##_end##nm##ent }, \
495 { #h"_set"#nm"ent", _nss_##h##_set##nm##ent },
496 # define DEFINE_GET(h,nm) \
497 { #h"_get"#nm"_r", _nss_##h##_get##nm##_r },
498 # define DEFINE_GETBY(h,nm,ky) \
499 { #h"_get"#nm"by"#ky"_r", _nss_##h##_get##nm##by##ky##_r },
500 static struct fct_tbl
{ const char *fname
; void *fp
; } *tp
, tbl
[] =
502 # include "function.def"
505 size_t namlen
= (5 + strlen (ni
->name
) + 1
506 + strlen (fct_name
) + 1);
509 /* Construct the function name. */
510 __stpcpy (__stpcpy (__stpcpy (name
, ni
->name
),
515 for (tp
= &tbl
[0]; tp
->fname
; tp
++)
516 if (strcmp (tp
->fname
, name
) == 0)
524 /* Remember function pointer for later calls. Even if null, we
525 record it so a second try needn't search the library again. */
526 known
->fct_ptr
= result
;
528 PTR_MANGLE (known
->fct_ptr
);
533 /* Remove the lock. */
534 __libc_lock_unlock (lock
);
538 libc_hidden_def (__nss_lookup_function
)
541 static name_database
*
542 nss_parse_file (const char *fname
)
545 name_database
*result
;
546 name_database_entry
*last
;
550 /* Open the configuration file. */
551 fp
= fopen (fname
, "rce");
555 /* No threads use this stream. */
556 __fsetlocking (fp
, FSETLOCKING_BYCALLER
);
558 result
= (name_database
*) malloc (sizeof (name_database
));
565 result
->entry
= NULL
;
566 result
->library
= NULL
;
572 name_database_entry
*this;
575 n
= __getline (&line
, &len
, fp
);
578 if (line
[n
- 1] == '\n')
581 /* Because the file format does not know any form of quoting we
582 can search forward for the next '#' character and if found
583 make it terminating the line. */
584 *__strchrnul (line
, '#') = '\0';
586 /* If the line is blank it is ignored. */
590 /* Each line completely specifies the actions for a database. */
591 this = nss_getline (line
);
597 result
->entry
= this;
602 while (!__feof_unlocked (fp
));
604 /* Free the buffer. */
606 /* Close configuration file. */
613 /* Read the source names:
614 `( <source> ( "[" "!"? (<status> "=" <action> )+ "]" )? )*'
616 static service_user
*
617 nss_parse_service_list (const char *line
)
619 service_user
*result
= NULL
, **nextp
= &result
;
623 service_user
*new_service
;
626 while (isspace (line
[0]))
629 /* No source specified. */
632 /* Read <source> identifier. */
634 while (line
[0] != '\0' && !isspace (line
[0]) && line
[0] != '[')
640 new_service
= (service_user
*) malloc (sizeof (service_user
)
641 + (line
- name
+ 1));
642 if (new_service
== NULL
)
645 *((char *) __mempcpy (new_service
->name
, name
, line
- name
)) = '\0';
647 /* Set default actions. */
648 new_service
->actions
[2 + NSS_STATUS_TRYAGAIN
] = NSS_ACTION_CONTINUE
;
649 new_service
->actions
[2 + NSS_STATUS_UNAVAIL
] = NSS_ACTION_CONTINUE
;
650 new_service
->actions
[2 + NSS_STATUS_NOTFOUND
] = NSS_ACTION_CONTINUE
;
651 new_service
->actions
[2 + NSS_STATUS_SUCCESS
] = NSS_ACTION_RETURN
;
652 new_service
->actions
[2 + NSS_STATUS_RETURN
] = NSS_ACTION_RETURN
;
653 new_service
->library
= NULL
;
654 new_service
->known
= NULL
;
655 new_service
->next
= NULL
;
657 while (isspace (line
[0]))
662 /* Read criterions. */
665 while (line
[0] != '\0' && isspace (line
[0]));
670 enum nss_status status
;
671 lookup_actions action
;
673 /* Grok ! before name to mean all statii but that one. */
674 not = line
[0] == '!';
678 /* Read status name. */
680 while (line
[0] != '\0' && !isspace (line
[0]) && line
[0] != '='
684 /* Compare with known statii. */
685 if (line
- name
== 7)
687 if (__strncasecmp (name
, "SUCCESS", 7) == 0)
688 status
= NSS_STATUS_SUCCESS
;
689 else if (__strncasecmp (name
, "UNAVAIL", 7) == 0)
690 status
= NSS_STATUS_UNAVAIL
;
694 else if (line
- name
== 8)
696 if (__strncasecmp (name
, "NOTFOUND", 8) == 0)
697 status
= NSS_STATUS_NOTFOUND
;
698 else if (__strncasecmp (name
, "TRYAGAIN", 8) == 0)
699 status
= NSS_STATUS_TRYAGAIN
;
706 while (isspace (line
[0]))
712 while (isspace (line
[0]));
715 while (line
[0] != '\0' && !isspace (line
[0]) && line
[0] != '='
719 if (line
- name
== 6 && __strncasecmp (name
, "RETURN", 6) == 0)
720 action
= NSS_ACTION_RETURN
;
721 else if (line
- name
== 8
722 && __strncasecmp (name
, "CONTINUE", 8) == 0)
723 action
= NSS_ACTION_CONTINUE
;
724 else if (line
- name
== 5
725 && __strncasecmp (name
, "MERGE", 5) == 0)
726 action
= NSS_ACTION_MERGE
;
732 /* Save the current action setting for this status,
733 set them all to the given action, and reset this one. */
734 const lookup_actions save
= new_service
->actions
[2 + status
];
735 new_service
->actions
[2 + NSS_STATUS_TRYAGAIN
] = action
;
736 new_service
->actions
[2 + NSS_STATUS_UNAVAIL
] = action
;
737 new_service
->actions
[2 + NSS_STATUS_NOTFOUND
] = action
;
738 new_service
->actions
[2 + NSS_STATUS_SUCCESS
] = action
;
739 new_service
->actions
[2 + status
] = save
;
742 new_service
->actions
[2 + status
] = action
;
744 /* Skip white spaces. */
745 while (isspace (line
[0]))
748 while (line
[0] != ']');
754 *nextp
= new_service
;
755 nextp
= &new_service
->next
;
764 static name_database_entry
*
765 nss_getline (char *line
)
768 name_database_entry
*result
;
771 /* Ignore leading white spaces. ATTENTION: this is different from
772 what is implemented in Solaris. The Solaris man page says a line
773 beginning with a white space character is ignored. We regard
774 this as just another misfeature in Solaris. */
775 while (isspace (line
[0]))
778 /* Recognize `<database> ":"'. */
780 while (line
[0] != '\0' && !isspace (line
[0]) && line
[0] != ':')
782 if (line
[0] == '\0' || name
== line
)
787 len
= strlen (name
) + 1;
789 result
= (name_database_entry
*) malloc (sizeof (name_database_entry
) + len
);
793 /* Save the database name. */
794 memcpy (result
->name
, name
, len
);
796 /* Parse the list of services. */
797 result
->service
= nss_parse_service_list (line
);
804 #if !defined DO_STATIC_NSS || defined SHARED
805 static service_library
*
806 nss_new_service (name_database
*database
, const char *name
)
808 service_library
**currentp
= &database
->library
;
810 while (*currentp
!= NULL
)
812 if (strcmp ((*currentp
)->name
, name
) == 0)
814 currentp
= &(*currentp
)->next
;
817 /* We have to add the new service. */
818 *currentp
= (service_library
*) malloc (sizeof (service_library
));
819 if (*currentp
== NULL
)
822 (*currentp
)->name
= name
;
823 (*currentp
)->lib_handle
= NULL
;
824 (*currentp
)->next
= NULL
;
831 #if defined SHARED && defined USE_NSCD
832 /* Load all libraries for the service. */
834 nss_load_all_libraries (const char *service
, const char *def
)
836 service_user
*ni
= NULL
;
838 if (__nss_database_lookup (service
, NULL
, def
, &ni
) == 0)
841 nss_load_library (ni
);
847 /* Called by nscd and nscd alone. */
849 __nss_disable_nscd (void (*cb
) (size_t, struct traced_file
*))
857 /* Find all the relevant modules so that the init functions are called. */
858 nss_load_all_libraries ("passwd", DEFAULT_CONFIG
);
859 nss_load_all_libraries ("group", DEFAULT_CONFIG
);
860 nss_load_all_libraries ("hosts", "dns [!UNAVAIL=return] files");
861 nss_load_all_libraries ("services", NULL
);
863 /* Disable all uses of NSCD. */
864 __nss_not_use_nscd_passwd
= -1;
865 __nss_not_use_nscd_group
= -1;
866 __nss_not_use_nscd_hosts
= -1;
867 __nss_not_use_nscd_services
= -1;
868 __nss_not_use_nscd_netgroup
= -1;
873 free_database_entries (name_database_entry
*entry
)
875 while (entry
!= NULL
)
877 name_database_entry
*olde
= entry
;
878 service_user
*service
= entry
->service
;
880 while (service
!= NULL
)
882 service_user
*olds
= service
;
884 if (service
->known
!= NULL
)
885 __tdestroy (service
->known
, free
);
887 service
= service
->next
;
896 /* Free all resources if necessary. */
897 libc_freeres_fn (free_defconfig
)
899 name_database_entry
*entry
= defconfig_entries
;
902 /* defconfig was not used. */
905 /* Don't disturb ongoing other threads (if there are any). */
906 defconfig_entries
= NULL
;
908 free_database_entries (entry
);
911 libc_freeres_fn (free_mem
)
913 name_database
*top
= service_table
;
914 service_library
*library
;
917 /* Maybe we have not read the nsswitch.conf file. */
920 /* Don't disturb ongoing other threads (if there are any). */
921 service_table
= NULL
;
923 free_database_entries (top
->entry
);
925 library
= top
->library
;
926 while (library
!= NULL
)
928 service_library
*oldl
= library
;
930 if (library
->lib_handle
&& library
->lib_handle
!= (void *) -1l)
931 __libc_dlclose (library
->lib_handle
);
933 library
= library
->next
;