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
) 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]))
77 /* Flags whether custom rules for database is set. */
78 bool __nss_database_custom
[NSS_DBSIDX_max
];
82 __libc_lock_define_initialized (static, lock
)
84 #if !defined DO_STATIC_NSS || defined SHARED
85 /* String with revision number of the shared object files. */
86 static const char *const __nss_shlib_revision
= LIBNSS_FILES_SO
+ 15;
89 /* The root of the whole data base. */
90 static name_database
*service_table
;
92 /* List of default service lists that were generated by glibc because
93 /etc/nsswitch.conf did not provide a value.
94 The list is only maintained so we can free such service lists in
96 static name_database_entry
*defconfig_entries
;
99 #if defined USE_NSCD && (!defined DO_STATIC_NSS || defined SHARED)
100 /* Nonzero if this is the nscd process. */
102 /* The callback passed to the init functions when nscd is used. */
103 static void (*nscd_init_cb
) (size_t, struct traced_file
*);
107 /* -1 == database not found
108 0 == database entry pointer stored */
110 __nss_database_lookup (const char *database
, const char *alternate_name
,
111 const char *defconfig
, service_user
**ni
)
113 /* Prevent multiple threads to change the service table. */
114 __libc_lock_lock (lock
);
116 /* Reconsider database variable in case some other thread called
117 `__nss_configure_lookup' while we waited for the lock. */
120 __libc_lock_unlock (lock
);
124 /* Are we initialized yet? */
125 if (service_table
== NULL
)
126 /* Read config file. */
127 service_table
= nss_parse_file (_PATH_NSSWITCH_CONF
);
129 /* Test whether configuration data is available. */
130 if (service_table
!= NULL
)
132 /* Return first `service_user' entry for DATABASE. */
133 name_database_entry
*entry
;
135 /* XXX Could use some faster mechanism here. But each database is
136 only requested once and so this might not be critical. */
137 for (entry
= service_table
->entry
; entry
!= NULL
; entry
= entry
->next
)
138 if (strcmp (database
, entry
->name
) == 0)
139 *ni
= entry
->service
;
141 if (*ni
== NULL
&& alternate_name
!= NULL
)
142 /* We haven't found an entry so far. Try to find it with the
144 for (entry
= service_table
->entry
; entry
!= NULL
; entry
= entry
->next
)
145 if (strcmp (alternate_name
, entry
->name
) == 0)
146 *ni
= entry
->service
;
149 /* No configuration data is available, either because nsswitch.conf
150 doesn't exist or because it doesn't have a line for this database.
152 DEFCONFIG specifies the default service list for this database,
153 or null to use the most common default. */
156 *ni
= nss_parse_service_list (defconfig
157 ?: "nis [NOTFOUND=return] files");
160 /* Record the memory we've just allocated in defconfig_entries list,
161 so we can free it later. */
162 name_database_entry
*entry
;
164 /* Allocate ENTRY plus size of name (1 here). */
165 entry
= (name_database_entry
*) malloc (sizeof (*entry
) + 1);
169 entry
->next
= defconfig_entries
;
170 entry
->service
= *ni
;
171 entry
->name
[0] = '\0';
172 defconfig_entries
= entry
;
177 __libc_lock_unlock (lock
);
179 return *ni
!= NULL
? 0 : -1;
181 libc_hidden_def (__nss_database_lookup
)
188 __nss_lookup (service_user
**ni
, const char *fct_name
, const char *fct2_name
,
191 *fctp
= __nss_lookup_function (*ni
, fct_name
);
192 if (*fctp
== NULL
&& fct2_name
!= NULL
)
193 *fctp
= __nss_lookup_function (*ni
, fct2_name
);
196 && nss_next_action (*ni
, NSS_STATUS_UNAVAIL
) == NSS_ACTION_CONTINUE
197 && (*ni
)->next
!= NULL
)
201 *fctp
= __nss_lookup_function (*ni
, fct_name
);
202 if (*fctp
== NULL
&& fct2_name
!= NULL
)
203 *fctp
= __nss_lookup_function (*ni
, fct2_name
);
206 return *fctp
!= NULL
? 0 : (*ni
)->next
== NULL
? 1 : -1;
208 libc_hidden_def (__nss_lookup
)
212 0 == adjusted for next function
215 __nss_next2 (service_user
**ni
, const char *fct_name
, const char *fct2_name
,
216 void **fctp
, int status
, int all_values
)
220 if (nss_next_action (*ni
, NSS_STATUS_TRYAGAIN
) == NSS_ACTION_RETURN
221 && nss_next_action (*ni
, NSS_STATUS_UNAVAIL
) == NSS_ACTION_RETURN
222 && nss_next_action (*ni
, NSS_STATUS_NOTFOUND
) == NSS_ACTION_RETURN
223 && nss_next_action (*ni
, NSS_STATUS_SUCCESS
) == NSS_ACTION_RETURN
)
228 /* This is really only for debugging. */
229 if (__builtin_expect (NSS_STATUS_TRYAGAIN
> status
230 || status
> NSS_STATUS_RETURN
, 0))
231 __libc_fatal ("illegal status in __nss_next");
233 if (nss_next_action (*ni
, status
) == NSS_ACTION_RETURN
)
237 if ((*ni
)->next
== NULL
)
244 *fctp
= __nss_lookup_function (*ni
, fct_name
);
245 if (*fctp
== NULL
&& fct2_name
!= NULL
)
246 *fctp
= __nss_lookup_function (*ni
, fct2_name
);
249 && nss_next_action (*ni
, NSS_STATUS_UNAVAIL
) == NSS_ACTION_CONTINUE
250 && (*ni
)->next
!= NULL
);
252 return *fctp
!= NULL
? 0 : -1;
254 libc_hidden_def (__nss_next2
)
258 attribute_compat_text_section
259 __nss_next (service_user
**ni
, const char *fct_name
, void **fctp
, int status
,
262 return __nss_next2 (ni
, fct_name
, NULL
, fctp
, status
, all_values
);
267 __nss_configure_lookup (const char *dbname
, const char *service_line
)
269 service_user
*new_db
;
272 for (cnt
= 0; cnt
< ndatabases
; ++cnt
)
274 int cmp
= strcmp (dbname
, databases
[cnt
].name
);
279 __set_errno (EINVAL
);
284 if (cnt
== ndatabases
)
286 __set_errno (EINVAL
);
290 /* Test whether it is really used. */
291 if (databases
[cnt
].dbp
== NULL
)
292 /* Nothing to do, but we could do. */
295 /* Try to generate new data. */
296 new_db
= nss_parse_service_list (service_line
);
299 /* Illegal service specification. */
300 __set_errno (EINVAL
);
304 /* Prevent multiple threads to change the service table. */
305 __libc_lock_lock (lock
);
307 /* Install new rules. */
308 *databases
[cnt
].dbp
= new_db
;
310 __nss_database_custom
[cnt
] = true;
313 __libc_lock_unlock (lock
);
319 /* Comparison function for searching NI->known tree. */
321 known_compare (const void *p1
, const void *p2
)
323 return p1
== p2
? 0 : strcmp (*(const char *const *) p1
,
324 *(const char *const *) p2
);
328 #if !defined DO_STATIC_NSS || defined SHARED
331 nss_load_library (service_user
*ni
)
333 if (ni
->library
== NULL
)
335 /* This service has not yet been used. Fetch the service
336 library for it, creating a new one if need be. If there
337 is no service table from the file, this static variable
338 holds the head of the service_library list made from the
339 default configuration. */
340 static name_database default_table
;
341 ni
->library
= nss_new_service (service_table
?: &default_table
,
343 if (ni
->library
== NULL
)
347 if (ni
->library
->lib_handle
== NULL
)
349 /* Load the shared library. */
350 size_t shlen
= (7 + strlen (ni
->name
) + 3
351 + strlen (__nss_shlib_revision
) + 1);
352 int saved_errno
= errno
;
353 char shlib_name
[shlen
];
355 /* Construct shared object name. */
356 __stpcpy (__stpcpy (__stpcpy (__stpcpy (shlib_name
,
360 __nss_shlib_revision
);
362 ni
->library
->lib_handle
= __libc_dlopen (shlib_name
);
363 if (ni
->library
->lib_handle
== NULL
)
365 /* Failed to load the library. */
366 ni
->library
->lib_handle
= (void *) -1l;
367 __set_errno (saved_errno
);
372 /* Call the init function when nscd is used. */
373 size_t initlen
= (5 + strlen (ni
->name
)
374 + strlen ("_init") + 1);
375 char init_name
[initlen
];
377 /* Construct the init function name. */
378 __stpcpy (__stpcpy (__stpcpy (init_name
,
383 /* Find the optional init function. */
384 void (*ifct
) (void (*) (size_t, struct traced_file
*))
385 = __libc_dlsym (ni
->library
->lib_handle
, init_name
);
388 void (*cb
) (size_t, struct traced_file
*) = nscd_init_cb
;
404 __nss_lookup_function (service_user
*ni
, const char *fct_name
)
406 void **found
, *result
;
408 /* We now modify global data. Protect it. */
409 __libc_lock_lock (lock
);
411 /* Search the tree of functions previously requested. Data in the
412 tree are `known_function' structures, whose first member is a
413 `const char *', the lookup key. The search returns a pointer to
414 the tree node structure; the first member of the is a pointer to
415 our structure (i.e. what will be a `known_function'); since the
416 first member of that is the lookup key string, &FCT_NAME is close
417 enough to a pointer to our structure to use as a lookup key that
418 will be passed to `known_compare' (above). */
420 found
= __tsearch (&fct_name
, &ni
->known
, &known_compare
);
422 /* This means out-of-memory. */
424 else if (*found
!= &fct_name
)
426 /* The search found an existing structure in the tree. */
427 result
= ((known_function
*) *found
)->fct_ptr
;
429 PTR_DEMANGLE (result
);
434 /* This name was not known before. Now we have a node in the tree
435 (in the proper sorted position for FCT_NAME) that points to
436 &FCT_NAME instead of any real `known_function' structure.
437 Allocate a new structure and fill it in. */
439 known_function
*known
= malloc (sizeof *known
);
442 #if !defined DO_STATIC_NSS || defined SHARED
445 /* Oops. We can't instantiate this node properly.
446 Remove it from the tree. */
447 __tdelete (&fct_name
, &ni
->known
, &known_compare
);
453 /* Point the tree node at this new structure. */
455 known
->fct_name
= fct_name
;
457 #if !defined DO_STATIC_NSS || defined SHARED
458 /* Load the appropriate library. */
459 if (nss_load_library (ni
) != 0)
460 /* This only happens when out of memory. */
461 goto remove_from_tree
;
463 if (ni
->library
->lib_handle
== (void *) -1l)
464 /* Library not found => function not found. */
468 /* Get the desired function. */
469 size_t namlen
= (5 + strlen (ni
->name
) + 1
470 + strlen (fct_name
) + 1);
473 /* Construct the function name. */
474 __stpcpy (__stpcpy (__stpcpy (__stpcpy (name
, "_nss_"),
479 /* Look up the symbol. */
480 result
= __libc_dlsym (ni
->library
->lib_handle
, name
);
483 /* We can't get function address dynamically in static linking. */
485 # define DEFINE_ENT(h,nm) \
486 { #h"_get"#nm"ent_r", _nss_##h##_get##nm##ent_r }, \
487 { #h"_end"#nm"ent", _nss_##h##_end##nm##ent }, \
488 { #h"_set"#nm"ent", _nss_##h##_set##nm##ent },
489 # define DEFINE_GET(h,nm) \
490 { #h"_get"#nm"_r", _nss_##h##_get##nm##_r },
491 # define DEFINE_GETBY(h,nm,ky) \
492 { #h"_get"#nm"by"#ky"_r", _nss_##h##_get##nm##by##ky##_r },
493 static struct fct_tbl
{ const char *fname
; void *fp
; } *tp
, tbl
[] =
495 # include "function.def"
498 size_t namlen
= (5 + strlen (ni
->name
) + 1
499 + strlen (fct_name
) + 1);
502 /* Construct the function name. */
503 __stpcpy (__stpcpy (__stpcpy (name
, ni
->name
),
508 for (tp
= &tbl
[0]; tp
->fname
; tp
++)
509 if (strcmp (tp
->fname
, name
) == 0)
517 /* Remember function pointer for later calls. Even if null, we
518 record it so a second try needn't search the library again. */
519 known
->fct_ptr
= result
;
521 PTR_MANGLE (known
->fct_ptr
);
526 /* Remove the lock. */
527 __libc_lock_unlock (lock
);
531 libc_hidden_def (__nss_lookup_function
)
534 static name_database
*
536 nss_parse_file (const char *fname
)
539 name_database
*result
;
540 name_database_entry
*last
;
544 /* Open the configuration file. */
545 fp
= fopen (fname
, "rce");
549 /* No threads use this stream. */
550 __fsetlocking (fp
, FSETLOCKING_BYCALLER
);
552 result
= (name_database
*) malloc (sizeof (name_database
));
559 result
->entry
= NULL
;
560 result
->library
= NULL
;
566 name_database_entry
*this;
569 n
= __getline (&line
, &len
, fp
);
572 if (line
[n
- 1] == '\n')
575 /* Because the file format does not know any form of quoting we
576 can search forward for the next '#' character and if found
577 make it terminating the line. */
578 *__strchrnul (line
, '#') = '\0';
580 /* If the line is blank it is ignored. */
584 /* Each line completely specifies the actions for a database. */
585 this = nss_getline (line
);
591 result
->entry
= this;
596 while (!feof_unlocked (fp
));
598 /* Free the buffer. */
600 /* Close configuration file. */
607 /* Read the source names:
608 `( <source> ( "[" "!"? (<status> "=" <action> )+ "]" )? )*'
610 static service_user
*
612 nss_parse_service_list (const char *line
)
614 service_user
*result
= NULL
, **nextp
= &result
;
618 service_user
*new_service
;
621 while (isspace (line
[0]))
624 /* No source specified. */
627 /* Read <source> identifier. */
629 while (line
[0] != '\0' && !isspace (line
[0]) && line
[0] != '[')
635 new_service
= (service_user
*) malloc (sizeof (service_user
)
636 + (line
- name
+ 1));
637 if (new_service
== NULL
)
640 *((char *) __mempcpy (new_service
->name
, name
, line
- name
)) = '\0';
642 /* Set default actions. */
643 new_service
->actions
[2 + NSS_STATUS_TRYAGAIN
] = NSS_ACTION_CONTINUE
;
644 new_service
->actions
[2 + NSS_STATUS_UNAVAIL
] = NSS_ACTION_CONTINUE
;
645 new_service
->actions
[2 + NSS_STATUS_NOTFOUND
] = NSS_ACTION_CONTINUE
;
646 new_service
->actions
[2 + NSS_STATUS_SUCCESS
] = NSS_ACTION_RETURN
;
647 new_service
->actions
[2 + NSS_STATUS_RETURN
] = NSS_ACTION_RETURN
;
648 new_service
->library
= NULL
;
649 new_service
->known
= NULL
;
650 new_service
->next
= NULL
;
652 while (isspace (line
[0]))
657 /* Read criterions. */
660 while (line
[0] != '\0' && isspace (line
[0]));
665 enum nss_status status
;
666 lookup_actions action
;
668 /* Grok ! before name to mean all statii but that one. */
669 not = line
[0] == '!';
673 /* Read status name. */
675 while (line
[0] != '\0' && !isspace (line
[0]) && line
[0] != '='
679 /* Compare with known statii. */
680 if (line
- name
== 7)
682 if (__strncasecmp (name
, "SUCCESS", 7) == 0)
683 status
= NSS_STATUS_SUCCESS
;
684 else if (__strncasecmp (name
, "UNAVAIL", 7) == 0)
685 status
= NSS_STATUS_UNAVAIL
;
689 else if (line
- name
== 8)
691 if (__strncasecmp (name
, "NOTFOUND", 8) == 0)
692 status
= NSS_STATUS_NOTFOUND
;
693 else if (__strncasecmp (name
, "TRYAGAIN", 8) == 0)
694 status
= NSS_STATUS_TRYAGAIN
;
701 while (isspace (line
[0]))
707 while (isspace (line
[0]));
710 while (line
[0] != '\0' && !isspace (line
[0]) && line
[0] != '='
714 if (line
- name
== 6 && __strncasecmp (name
, "RETURN", 6) == 0)
715 action
= NSS_ACTION_RETURN
;
716 else if (line
- name
== 8
717 && __strncasecmp (name
, "CONTINUE", 8) == 0)
718 action
= NSS_ACTION_CONTINUE
;
719 else if (line
- name
== 5
720 && __strncasecmp (name
, "MERGE", 5) == 0)
721 action
= NSS_ACTION_MERGE
;
727 /* Save the current action setting for this status,
728 set them all to the given action, and reset this one. */
729 const lookup_actions save
= new_service
->actions
[2 + status
];
730 new_service
->actions
[2 + NSS_STATUS_TRYAGAIN
] = action
;
731 new_service
->actions
[2 + NSS_STATUS_UNAVAIL
] = action
;
732 new_service
->actions
[2 + NSS_STATUS_NOTFOUND
] = action
;
733 new_service
->actions
[2 + NSS_STATUS_SUCCESS
] = action
;
734 new_service
->actions
[2 + status
] = save
;
737 new_service
->actions
[2 + status
] = action
;
739 /* Skip white spaces. */
740 while (isspace (line
[0]))
743 while (line
[0] != ']');
749 *nextp
= new_service
;
750 nextp
= &new_service
->next
;
759 static name_database_entry
*
761 nss_getline (char *line
)
764 name_database_entry
*result
;
767 /* Ignore leading white spaces. ATTENTION: this is different from
768 what is implemented in Solaris. The Solaris man page says a line
769 beginning with a white space character is ignored. We regard
770 this as just another misfeature in Solaris. */
771 while (isspace (line
[0]))
774 /* Recognize `<database> ":"'. */
776 while (line
[0] != '\0' && !isspace (line
[0]) && line
[0] != ':')
778 if (line
[0] == '\0' || name
== line
)
783 len
= strlen (name
) + 1;
785 result
= (name_database_entry
*) malloc (sizeof (name_database_entry
) + len
);
789 /* Save the database name. */
790 memcpy (result
->name
, name
, len
);
792 /* Parse the list of services. */
793 result
->service
= nss_parse_service_list (line
);
800 #if !defined DO_STATIC_NSS || defined SHARED
801 static service_library
*
803 nss_new_service (name_database
*database
, const char *name
)
805 service_library
**currentp
= &database
->library
;
807 while (*currentp
!= NULL
)
809 if (strcmp ((*currentp
)->name
, name
) == 0)
811 currentp
= &(*currentp
)->next
;
814 /* We have to add the new service. */
815 *currentp
= (service_library
*) malloc (sizeof (service_library
));
816 if (*currentp
== NULL
)
819 (*currentp
)->name
= name
;
820 (*currentp
)->lib_handle
= NULL
;
821 (*currentp
)->next
= NULL
;
828 #if defined SHARED && defined USE_NSCD
829 /* Load all libraries for the service. */
831 nss_load_all_libraries (const char *service
, const char *def
)
833 service_user
*ni
= NULL
;
835 if (__nss_database_lookup (service
, NULL
, def
, &ni
) == 0)
838 nss_load_library (ni
);
844 /* Called by nscd and nscd alone. */
846 __nss_disable_nscd (void (*cb
) (size_t, struct traced_file
*))
854 /* Find all the relevant modules so that the init functions are called. */
855 nss_load_all_libraries ("passwd", "compat [NOTFOUND=return] files");
856 nss_load_all_libraries ("group", "compat [NOTFOUND=return] files");
857 nss_load_all_libraries ("hosts", "dns [!UNAVAIL=return] files");
858 nss_load_all_libraries ("services", NULL
);
860 /* Disable all uses of NSCD. */
861 __nss_not_use_nscd_passwd
= -1;
862 __nss_not_use_nscd_group
= -1;
863 __nss_not_use_nscd_hosts
= -1;
864 __nss_not_use_nscd_services
= -1;
865 __nss_not_use_nscd_netgroup
= -1;
870 free_database_entries (name_database_entry
*entry
)
872 while (entry
!= NULL
)
874 name_database_entry
*olde
= entry
;
875 service_user
*service
= entry
->service
;
877 while (service
!= NULL
)
879 service_user
*olds
= service
;
881 if (service
->known
!= NULL
)
882 __tdestroy (service
->known
, free
);
884 service
= service
->next
;
893 /* Free all resources if necessary. */
894 libc_freeres_fn (free_defconfig
)
896 name_database_entry
*entry
= defconfig_entries
;
899 /* defconfig was not used. */
902 /* Don't disturb ongoing other threads (if there are any). */
903 defconfig_entries
= NULL
;
905 free_database_entries (entry
);
908 libc_freeres_fn (free_mem
)
910 name_database
*top
= service_table
;
911 service_library
*library
;
914 /* Maybe we have not read the nsswitch.conf file. */
917 /* Don't disturb ongoing other threads (if there are any). */
918 service_table
= NULL
;
920 free_database_entries (top
->entry
);
922 library
= top
->library
;
923 while (library
!= NULL
)
925 service_library
*oldl
= library
;
927 if (library
->lib_handle
&& library
->lib_handle
!= (void *) -1l)
928 __libc_dlclose (library
->lib_handle
);
930 library
= library
->next
;