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nsswitch: use new internal API (core)

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Core changes to switch the NSS internals to use the new API.

Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
This commit is contained in:
DJ Delorie 2020-11-09 22:06:57 -05:00
parent fa78feca47
commit f8847d83e1
8 changed files with 169 additions and 846 deletions
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4
malloc/set-freeres.c
View File

@ -20,7 +20,7 @@
#include <set-hooks.h>
#include <libc-internal.h>
#include "../nss/nss_module.h"
#include "../nss/nsswitch.h"
#include "../libio/libioP.h"
DEFINE_HOOK (__libc_subfreeres, (void));
@ -43,6 +43,8 @@ __libc_freeres (void)
void *const *p;
call_function_static_weak (__nss_module_freeres);
call_function_static_weak (__nss_action_freeres);
call_function_static_weak (__nss_database_freeres);
_IO_cleanup ();

3
nss/Makefile
View File

@ -66,7 +66,8 @@ tests-container = \
tst-nss-test3 \
tst-nss-files-hosts-long \
tst-nss-db-endpwent \
tst-nss-db-endgrent
tst-nss-db-endgrent \
tst-reload1
# Tests which need libdl
ifeq (yes,$(build-shared))

2
nss/nss_action.c
View File

@ -16,7 +16,7 @@
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <nss_action.h>
#include <nsswitch.h>
#include <string.h>
#include <libc-lock.h>

22
nss/nss_action_parse.c
View File

@ -16,8 +16,7 @@
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include "nss_action.h"
#include "nss_module.h"
#include <nsswitch.h>
#include <ctype.h>
#include <string.h>
@ -169,18 +168,13 @@ nss_action_list
action_list_init (&list);
if (nss_action_parse (line, &list))
{
size_t size = action_list_size (&list);
nss_action_list result
= malloc (sizeof (*result) * (size + 1));
if (result == NULL)
{
action_list_free (&list);
return NULL;
}
memcpy (result, action_list_begin (&list), sizeof (*result) * size);
/* Sentinel. */
result[size].module = NULL;
return result;
size_t size;
struct nss_action null_service
= { .module = NULL, };
action_list_add (&list, null_service);
size = action_list_size (&list);
return __nss_action_allocate (action_list_begin (&list), size);
}
else if (action_list_has_failed (&list))
{

40
nss/nss_database.c
View File

@ -226,6 +226,39 @@ process_line (struct nss_database_data *data, char *line)
return true;
}
int
__nss_configure_lookup (const char *dbname, const char *service_line)
{
int db;
nss_action_list result;
struct nss_database_state *local;
/* Convert named database to index. */
db = name_to_database_index (dbname);
if (db < 0)
/* Not our database (e.g., sudoers). */
return -1;
/* Force any load/cache/read whatever to happen, so we can override
it. */
__nss_database_get (db, &result);
local = nss_database_state_get ();
result = __nss_action_parse (service_line);
if (result == NULL)
return -1;
atomic_store_release (&local->data.reload_disabled, 1);
local->data.services[db] = result;
#ifdef USE_NSCD
__nss_database_custom[db] = true;
#endif
return 0;
}
/* Iterate over the lines in FP, parse them, and store them in DATA.
Return false on memory allocation failure, true on success. */
static bool
@ -326,8 +359,11 @@ nss_database_check_reload_and_get (struct nss_database_state *local,
may have loaded the configuration first, so synchronize with the
Release MO store there. */
if (atomic_load_acquire (&local->data.reload_disabled))
/* No reload, so there is no error. */
return true;
{
*result = local->data.services[database_index];
/* No reload, so there is no error. */
return true;
}
struct file_change_detection initial;
if (!__file_change_detection_for_path (&initial, _PATH_NSSWITCH_CONF))

64
nss/nss_module.c
View File

@ -16,7 +16,9 @@
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <nss_module.h>
#include <nsswitch.h>
#include <nscd/nscd.h>
#include <nscd/nscd_proto.h>
#include <array_length.h>
#include <assert.h>
@ -287,6 +289,66 @@ __nss_module_get_function (struct nss_module *module, const char *name)
return fptr;
}
#if defined SHARED && defined USE_NSCD
/* Load all libraries for the service. */
static void
nss_load_all_libraries (const char *service, const char *def)
{
nss_action_list ni = NULL;
if (__nss_database_lookup2 (service, NULL, def, &ni) == 0)
while (ni->module != NULL)
{
__nss_module_load (ni->module);
++ni;
}
}
define_traced_file (pwd, _PATH_NSSWITCH_CONF);
define_traced_file (grp, _PATH_NSSWITCH_CONF);
define_traced_file (hst, _PATH_NSSWITCH_CONF);
define_traced_file (serv, _PATH_NSSWITCH_CONF);
define_traced_file (netgr, _PATH_NSSWITCH_CONF);
/* Called by nscd and nscd alone. */
void
__nss_disable_nscd (void (*cb) (size_t, struct traced_file *))
{
void (*cb1) (size_t, struct traced_file *);
cb1 = cb;
# ifdef PTR_MANGLE
PTR_MANGLE (cb);
# endif
nscd_init_cb = cb;
is_nscd = true;
/* Find all the relevant modules so that the init functions are called. */
nss_load_all_libraries ("passwd", DEFAULT_CONFIG);
nss_load_all_libraries ("group", DEFAULT_CONFIG);
nss_load_all_libraries ("hosts", "dns [!UNAVAIL=return] files");
nss_load_all_libraries ("services", NULL);
/* Make sure NSCD purges its cache if nsswitch.conf changes. */
init_traced_file (&pwd_traced_file.file, _PATH_NSSWITCH_CONF, 0);
cb1 (pwddb, &pwd_traced_file.file);
init_traced_file (&grp_traced_file.file, _PATH_NSSWITCH_CONF, 0);
cb1 (grpdb, &grp_traced_file.file);
init_traced_file (&hst_traced_file.file, _PATH_NSSWITCH_CONF, 0);
cb1 (hstdb, &hst_traced_file.file);
init_traced_file (&serv_traced_file.file, _PATH_NSSWITCH_CONF, 0);
cb1 (servdb, &serv_traced_file.file);
init_traced_file (&netgr_traced_file.file, _PATH_NSSWITCH_CONF, 0);
cb1 (netgrdb, &netgr_traced_file.file);
/* Disable all uses of NSCD. */
__nss_not_use_nscd_passwd = -1;
__nss_not_use_nscd_group = -1;
__nss_not_use_nscd_hosts = -1;
__nss_not_use_nscd_services = -1;
__nss_not_use_nscd_netgroup = -1;
}
#endif
void __libc_freeres_fn_section
__nss_module_freeres (void)
{

811
nss/nsswitch.c
View File

@ -32,6 +32,7 @@
#include <netinet/ether.h>
#include <pwd.h>
#include <shadow.h>
#include <unistd.h>
#if !defined DO_STATIC_NSS || defined SHARED
# include <gnu/lib-names.h>
@ -42,36 +43,20 @@
#include <sysdep.h>
#include <config.h>
/* Prototypes for the local functions. */
static name_database *nss_parse_file (const char *fname);
static name_database_entry *nss_getline (char *line);
static service_user *nss_parse_service_list (const char *line);
#if !defined DO_STATIC_NSS || defined SHARED
static service_library *nss_new_service (name_database *database,
const char *name);
#endif
/* Declare external database variables. */
#define DEFINE_DATABASE(name) \
service_user *__nss_##name##_database attribute_hidden; \
nss_action_list __nss_##name##_database attribute_hidden; \
weak_extern (__nss_##name##_database)
#include "databases.def"
#undef DEFINE_DATABASE
/* Structure to map database name to variable. */
static const struct
{
const char name[10];
service_user **dbp;
} databases[] =
{
#define DEFINE_DATABASE(name) \
{ #name, &__nss_##name##_database },
#include "databases.def"
#undef DEFINE_DATABASE
#define DEFINE_DATABASE(name) #name,
static const char * database_names[] = {
#include "databases.def"
NULL
};
#define ndatabases (sizeof (databases) / sizeof (databases[0]))
#ifdef USE_NSCD
/* Flags whether custom rules for database is set. */
@ -79,103 +64,33 @@ bool __nss_database_custom[NSS_DBSIDX_max];
#endif
__libc_lock_define_initialized (static, lock)
#if !defined DO_STATIC_NSS || defined SHARED
/* String with revision number of the shared object files. */
static const char *const __nss_shlib_revision = LIBNSS_FILES_SO + 15;
#endif
/* The root of the whole data base. */
static name_database *service_table;
/* List of default service lists that were generated by glibc because
/etc/nsswitch.conf did not provide a value.
The list is only maintained so we can free such service lists in
__libc_freeres. */
static name_database_entry *defconfig_entries;
#if defined USE_NSCD && (!defined DO_STATIC_NSS || defined SHARED)
/* Nonzero if this is the nscd process. */
static bool is_nscd;
/* The callback passed to the init functions when nscd is used. */
static void (*nscd_init_cb) (size_t, struct traced_file *);
#endif
/*__libc_lock_define_initialized (static, lock)*/
/* -1 == database not found
0 == database entry pointer stored */
int
__nss_database_lookup2 (const char *database, const char *alternate_name,
const char *defconfig, service_user **ni)
const char *defconfig, nss_action_list *ni)
{
/* Prevent multiple threads to change the service table. */
__libc_lock_lock (lock);
int database_id;
/* Reconsider database variable in case some other thread called
`__nss_configure_lookup' while we waited for the lock. */
if (*ni != NULL)
for (database_id = 0; database_names[database_id]; database_id++)
if (strcmp (database_names[database_id], database) == 0)
break;
if (database_names[database_id] == NULL)
return -1;
if (__nss_database_get (database_id, ni))
{
__libc_lock_unlock (lock);
/* Success. */
return 0;
}
/* Are we initialized yet? */
if (service_table == NULL)
/* Read config file. */
service_table = nss_parse_file (_PATH_NSSWITCH_CONF);
/* Test whether configuration data is available. */
if (service_table != NULL)
else
{
/* Return first `service_user' entry for DATABASE. */
name_database_entry *entry;
/* XXX Could use some faster mechanism here. But each database is
only requested once and so this might not be critical. */
for (entry = service_table->entry; entry != NULL; entry = entry->next)
if (strcmp (database, entry->name) == 0)
*ni = entry->service;
if (*ni == NULL && alternate_name != NULL)
/* We haven't found an entry so far. Try to find it with the
alternative name. */
for (entry = service_table->entry; entry != NULL; entry = entry->next)
if (strcmp (alternate_name, entry->name) == 0)
*ni = entry->service;
/* Failure. */
return -1;
}
/* No configuration data is available, either because nsswitch.conf
doesn't exist or because it doesn't have a line for this database.
DEFCONFIG specifies the default service list for this database,
or null to use the most common default. */
if (*ni == NULL)
{
*ni = nss_parse_service_list (defconfig ?: "files");
if (*ni != NULL)
{
/* Record the memory we've just allocated in defconfig_entries list,
so we can free it later. */
name_database_entry *entry;
/* Allocate ENTRY plus size of name (1 here). */
entry = (name_database_entry *) malloc (sizeof (*entry) + 1);
if (entry != NULL)
{
entry->next = defconfig_entries;
entry->service = *ni;
entry->name[0] = '\0';
defconfig_entries = entry;
}
}
}
__libc_lock_unlock (lock);
return *ni != NULL ? 0 : -1;
}
libc_hidden_def (__nss_database_lookup2)
@ -184,7 +99,7 @@ libc_hidden_def (__nss_database_lookup2)
0 == function found
1 == finished */
int
__nss_lookup (service_user **ni, const char *fct_name, const char *fct2_name,
__nss_lookup (nss_action_list *ni, const char *fct_name, const char *fct2_name,
void **fctp)
{
*fctp = __nss_lookup_function (*ni, fct_name);
@ -193,16 +108,16 @@ __nss_lookup (service_user **ni, const char *fct_name, const char *fct2_name,
while (*fctp == NULL
&& nss_next_action (*ni, NSS_STATUS_UNAVAIL) == NSS_ACTION_CONTINUE
&& (*ni)->next != NULL)
&& (*ni)[1].module != NULL)
{
*ni = (*ni)->next;
++(*ni);
*fctp = __nss_lookup_function (*ni, fct_name);
if (*fctp == NULL && fct2_name != NULL)
*fctp = __nss_lookup_function (*ni, fct2_name);
}
return *fctp != NULL ? 0 : (*ni)->next == NULL ? 1 : -1;
return *fctp != NULL ? 0 : (*ni)[1].module == NULL ? 1 : -1;
}
libc_hidden_def (__nss_lookup)
@ -211,7 +126,7 @@ libc_hidden_def (__nss_lookup)
0 == adjusted for next function
1 == finished */
int
__nss_next2 (service_user **ni, const char *fct_name, const char *fct2_name,
__nss_next2 (nss_action_list *ni, const char *fct_name, const char *fct2_name,
void **fctp, int status, int all_values)
{
if (all_values)
@ -233,12 +148,12 @@ __nss_next2 (service_user **ni, const char *fct_name, const char *fct2_name,
return 1;
}
if ((*ni)->next == NULL)
if ((*ni)[1].module == NULL)
return -1;
do
{
*ni = (*ni)->next;
++(*ni);
*fctp = __nss_lookup_function (*ni, fct_name);
if (*fctp == NULL && fct2_name != NULL)
@ -246,675 +161,17 @@ __nss_next2 (service_user **ni, const char *fct_name, const char *fct2_name,
}
while (*fctp == NULL
&& nss_next_action (*ni, NSS_STATUS_UNAVAIL) == NSS_ACTION_CONTINUE
&& (*ni)->next != NULL);
&& (*ni)[1].module != NULL);
return *fctp != NULL ? 0 : -1;
}
libc_hidden_def (__nss_next2)
int
__nss_configure_lookup (const char *dbname, const char *service_line)
{
service_user *new_db;
size_t cnt;
for (cnt = 0; cnt < ndatabases; ++cnt)
{
int cmp = strcmp (dbname, databases[cnt].name);
if (cmp == 0)
break;
if (cmp < 0)
{
__set_errno (EINVAL);
return -1;
}
}
if (cnt == ndatabases)
{
__set_errno (EINVAL);
return -1;
}
/* Test whether it is really used. */
if (databases[cnt].dbp == NULL)
/* Nothing to do, but we could do. */
return 0;
/* Try to generate new data. */
new_db = nss_parse_service_list (service_line);
if (new_db == NULL)
{
/* Illegal service specification. */
__set_errno (EINVAL);
return -1;
}
/* Prevent multiple threads to change the service table. */
__libc_lock_lock (lock);
/* Install new rules. */
*databases[cnt].dbp = new_db;
#ifdef USE_NSCD
__nss_database_custom[cnt] = true;
#endif
__libc_lock_unlock (lock);
return 0;
}
/* Comparison function for searching NI->known tree. */
static int
known_compare (const void *p1, const void *p2)
{
return p1 == p2 ? 0 : strcmp (*(const char *const *) p1,
*(const char *const *) p2);
}
#if !defined DO_STATIC_NSS || defined SHARED
/* Load library. */
static int
nss_load_library (service_user *ni)
{
if (ni->library == NULL)
{
/* This service has not yet been used. Fetch the service
library for it, creating a new one if need be. If there
is no service table from the file, this static variable
holds the head of the service_library list made from the
default configuration. */
static name_database default_table;
ni->library = nss_new_service (service_table ?: &default_table,
ni->name);
if (ni->library == NULL)
return -1;
}
if (ni->library->lib_handle == NULL)
{
/* Load the shared library. */
size_t shlen = (7 + strlen (ni->name) + 3
+ strlen (__nss_shlib_revision) + 1);
int saved_errno = errno;
char shlib_name[shlen];
/* Construct shared object name. */
__stpcpy (__stpcpy (__stpcpy (__stpcpy (shlib_name,
"libnss_"),
ni->name),
".so"),
__nss_shlib_revision);
ni->library->lib_handle = __libc_dlopen (shlib_name);
if (ni->library->lib_handle == NULL)
{
/* Failed to load the library. */
ni->library->lib_handle = (void *) -1l;
__set_errno (saved_errno);
}
# ifdef USE_NSCD
else if (is_nscd)
{
/* Call the init function when nscd is used. */
size_t initlen = (5 + strlen (ni->name)
+ strlen ("_init") + 1);
char init_name[initlen];
/* Construct the init function name. */
__stpcpy (__stpcpy (__stpcpy (init_name,
"_nss_"),
ni->name),
"_init");
/* Find the optional init function. */
void (*ifct) (void (*) (size_t, struct traced_file *))
= __libc_dlsym (ni->library->lib_handle, init_name);
if (ifct != NULL)
{
void (*cb) (size_t, struct traced_file *) = nscd_init_cb;
# ifdef PTR_DEMANGLE
PTR_DEMANGLE (cb);
# endif
ifct (cb);
}
}
# endif
}
return 0;
}
#endif
void *
__nss_lookup_function (service_user *ni, const char *fct_name)
__nss_lookup_function (nss_action_list ni, const char *fct_name)
{
void **found, *result;
/* We now modify global data. Protect it. */
__libc_lock_lock (lock);
/* Search the tree of functions previously requested. Data in the
tree are `known_function' structures, whose first member is a
`const char *', the lookup key. The search returns a pointer to
the tree node structure; the first member of the is a pointer to
our structure (i.e. what will be a `known_function'); since the
first member of that is the lookup key string, &FCT_NAME is close
enough to a pointer to our structure to use as a lookup key that
will be passed to `known_compare' (above). */
found = __tsearch (&fct_name, &ni->known, &known_compare);
if (found == NULL)
/* This means out-of-memory. */
result = NULL;
else if (*found != &fct_name)
{
/* The search found an existing structure in the tree. */
result = ((known_function *) *found)->fct_ptr;
#ifdef PTR_DEMANGLE
PTR_DEMANGLE (result);
#endif
}
else
{
/* This name was not known before. Now we have a node in the tree
(in the proper sorted position for FCT_NAME) that points to
&FCT_NAME instead of any real `known_function' structure.
Allocate a new structure and fill it in. */
known_function *known = malloc (sizeof *known);
if (! known)
{
#if !defined DO_STATIC_NSS || defined SHARED
remove_from_tree:
#endif
/* Oops. We can't instantiate this node properly.
Remove it from the tree. */
__tdelete (&fct_name, &ni->known, &known_compare);
free (known);
result = NULL;
}
else
{
/* Point the tree node at this new structure. */
*found = known;
known->fct_name = fct_name;
#if !defined DO_STATIC_NSS || defined SHARED
/* Load the appropriate library. */
if (nss_load_library (ni) != 0)
/* This only happens when out of memory. */
goto remove_from_tree;
if (ni->library->lib_handle == (void *) -1l)
/* Library not found => function not found. */
result = NULL;
else
{
/* Get the desired function. */
size_t namlen = (5 + strlen (ni->name) + 1
+ strlen (fct_name) + 1);
char name[namlen];
/* Construct the function name. */
__stpcpy (__stpcpy (__stpcpy (__stpcpy (name, "_nss_"),
ni->name),
"_"),
fct_name);
/* Look up the symbol. */
result = __libc_dlsym (ni->library->lib_handle, name);
}
#else
/* We can't get function address dynamically in static linking. */
{
# define DEFINE_ENT(h,nm) \
{ #h"_get"#nm"ent_r", _nss_##h##_get##nm##ent_r }, \
{ #h"_end"#nm"ent", _nss_##h##_end##nm##ent }, \
{ #h"_set"#nm"ent", _nss_##h##_set##nm##ent },
# define DEFINE_GET(h,nm) \
{ #h"_get"#nm"_r", _nss_##h##_get##nm##_r },
# define DEFINE_GETBY(h,nm,ky) \
{ #h"_get"#nm"by"#ky"_r", _nss_##h##_get##nm##by##ky##_r },
static struct fct_tbl { const char *fname; void *fp; } *tp, tbl[] =
{
# include "function.def"
{ NULL, NULL }
};
size_t namlen = (5 + strlen (ni->name) + 1
+ strlen (fct_name) + 1);
char name[namlen];
/* Construct the function name. */
__stpcpy (__stpcpy (__stpcpy (name, ni->name),
"_"),
fct_name);
result = NULL;
for (tp = &tbl[0]; tp->fname; tp++)
if (strcmp (tp->fname, name) == 0)
{
result = tp->fp;
break;
}
}
#endif
/* Remember function pointer for later calls. Even if null, we
record it so a second try needn't search the library again. */
known->fct_ptr = result;
#ifdef PTR_MANGLE
PTR_MANGLE (known->fct_ptr);
#endif
}
}
/* Remove the lock. */
__libc_lock_unlock (lock);
return result;
if (ni->module == NULL)
return NULL;
return __nss_module_get_function (ni->module, fct_name);
}
libc_hidden_def (__nss_lookup_function)
static name_database *
nss_parse_file (const char *fname)
{
FILE *fp;
name_database *result;
name_database_entry *last;
char *line;
size_t len;
/* Open the configuration file. */
fp = fopen (fname, "rce");
if (fp == NULL)
return NULL;
/* No threads use this stream. */
__fsetlocking (fp, FSETLOCKING_BYCALLER);
result = (name_database *) malloc (sizeof (name_database));
if (result == NULL)
{
fclose (fp);
return NULL;
}
result->entry = NULL;
result->library = NULL;
last = NULL;
line = NULL;
len = 0;
do
{
name_database_entry *this;
ssize_t n;
n = __getline (&line, &len, fp);
if (n < 0)
break;
if (line[n - 1] == '\n')
line[n - 1] = '\0';
/* Because the file format does not know any form of quoting we
can search forward for the next '#' character and if found
make it terminating the line. */
*__strchrnul (line, '#') = '\0';
/* If the line is blank it is ignored. */
if (line[0] == '\0')
continue;
/* Each line completely specifies the actions for a database. */
this = nss_getline (line);
if (this != NULL)
{
if (last != NULL)
last->next = this;
else
result->entry = this;
last = this;
}
}
while (!__feof_unlocked (fp));
/* Free the buffer. */
free (line);
/* Close configuration file. */
fclose (fp);
return result;
}
/* Read the source names:
`( <source> ( "[" "!"? (<status> "=" <action> )+ "]" )? )*'
*/
static service_user *
nss_parse_service_list (const char *line)
{
service_user *result = NULL, **nextp = &result;
while (1)
{
service_user *new_service;
const char *name;
while (isspace (line[0]))
++line;
if (line[0] == '\0')
/* No source specified. */
return result;
/* Read <source> identifier. */
name = line;
while (line[0] != '\0' && !isspace (line[0]) && line[0] != '[')
++line;
if (name == line)
return result;
new_service = (service_user *) malloc (sizeof (service_user)
+ (line - name + 1));
if (new_service == NULL)
return result;
*((char *) __mempcpy (new_service->name, name, line - name)) = '\0';
/* Set default actions. */
new_service->actions[2 + NSS_STATUS_TRYAGAIN] = NSS_ACTION_CONTINUE;
new_service->actions[2 + NSS_STATUS_UNAVAIL] = NSS_ACTION_CONTINUE;
new_service->actions[2 + NSS_STATUS_NOTFOUND] = NSS_ACTION_CONTINUE;
new_service->actions[2 + NSS_STATUS_SUCCESS] = NSS_ACTION_RETURN;
new_service->actions[2 + NSS_STATUS_RETURN] = NSS_ACTION_RETURN;
new_service->library = NULL;
new_service->known = NULL;
new_service->next = NULL;
while (isspace (line[0]))
++line;
if (line[0] == '[')
{
/* Read criterions. */
do
++line;
while (line[0] != '\0' && isspace (line[0]));
do
{
int not;
enum nss_status status;
lookup_actions action;
/* Grok ! before name to mean all statii but that one. */
not = line[0] == '!';
if (not)
++line;
/* Read status name. */
name = line;
while (line[0] != '\0' && !isspace (line[0]) && line[0] != '='
&& line[0] != ']')
++line;
/* Compare with known statii. */
if (line - name == 7)
{
if (__strncasecmp (name, "SUCCESS", 7) == 0)
status = NSS_STATUS_SUCCESS;
else if (__strncasecmp (name, "UNAVAIL", 7) == 0)
status = NSS_STATUS_UNAVAIL;
else
goto finish;
}
else if (line - name == 8)
{
if (__strncasecmp (name, "NOTFOUND", 8) == 0)
status = NSS_STATUS_NOTFOUND;
else if (__strncasecmp (name, "TRYAGAIN", 8) == 0)
status = NSS_STATUS_TRYAGAIN;
else
goto finish;
}
else
goto finish;
while (isspace (line[0]))
++line;
if (line[0] != '=')
goto finish;
do
++line;
while (isspace (line[0]));
name = line;
while (line[0] != '\0' && !isspace (line[0]) && line[0] != '='
&& line[0] != ']')
++line;
if (line - name == 6 && __strncasecmp (name, "RETURN", 6) == 0)
action = NSS_ACTION_RETURN;
else if (line - name == 8
&& __strncasecmp (name, "CONTINUE", 8) == 0)
action = NSS_ACTION_CONTINUE;
else if (line - name == 5
&& __strncasecmp (name, "MERGE", 5) == 0)
action = NSS_ACTION_MERGE;
else
goto finish;
if (not)
{
/* Save the current action setting for this status,
set them all to the given action, and reset this one. */
const lookup_actions save = new_service->actions[2 + status];
new_service->actions[2 + NSS_STATUS_TRYAGAIN] = action;
new_service->actions[2 + NSS_STATUS_UNAVAIL] = action;
new_service->actions[2 + NSS_STATUS_NOTFOUND] = action;
new_service->actions[2 + NSS_STATUS_SUCCESS] = action;
new_service->actions[2 + status] = save;
}
else
new_service->actions[2 + status] = action;
/* Skip white spaces. */
while (isspace (line[0]))
++line;
}
while (line[0] != ']');
/* Skip the ']'. */
++line;
}
*nextp = new_service;
nextp = &new_service->next;
continue;
finish:
free (new_service);
return result;
}
}
static name_database_entry *
nss_getline (char *line)
{
const char *name;
name_database_entry *result;
size_t len;
/* Ignore leading white spaces. ATTENTION: this is different from
what is implemented in Solaris. The Solaris man page says a line
beginning with a white space character is ignored. We regard
this as just another misfeature in Solaris. */
while (isspace (line[0]))
++line;
/* Recognize `<database> ":"'. */
name = line;
while (line[0] != '\0' && !isspace (line[0]) && line[0] != ':')
++line;
if (line[0] == '\0' || name == line)
/* Syntax error. */
return NULL;
*line++ = '\0';
len = strlen (name) + 1;
result = (name_database_entry *) malloc (sizeof (name_database_entry) + len);
if (result == NULL)
return NULL;
/* Save the database name. */
memcpy (result->name, name, len);
/* Parse the list of services. */
result->service = nss_parse_service_list (line);
result->next = NULL;
return result;
}
#if !defined DO_STATIC_NSS || defined SHARED
static service_library *
nss_new_service (name_database *database, const char *name)
{
service_library **currentp = &database->library;
while (*currentp != NULL)
{
if (strcmp ((*currentp)->name, name) == 0)
return *currentp;
currentp = &(*currentp)->next;
}
/* We have to add the new service. */
*currentp = (service_library *) malloc (sizeof (service_library));
if (*currentp == NULL)
return NULL;
(*currentp)->name = name;
(*currentp)->lib_handle = NULL;
(*currentp)->next = NULL;
return *currentp;
}
#endif
#if defined SHARED && defined USE_NSCD
/* Load all libraries for the service. */
static void
nss_load_all_libraries (const char *service, const char *def)
{
service_user *ni = NULL;
if (__nss_database_lookup2 (service, NULL, def, &ni) == 0)
while (ni != NULL)
{
nss_load_library (ni);
ni = ni->next;
}
}
/* Called by nscd and nscd alone. */
void
__nss_disable_nscd (void (*cb) (size_t, struct traced_file *))
{
# ifdef PTR_MANGLE
PTR_MANGLE (cb);
# endif
nscd_init_cb = cb;
is_nscd = true;
/* Find all the relevant modules so that the init functions are called. */
nss_load_all_libraries ("passwd", "files");
nss_load_all_libraries ("group", "files");
nss_load_all_libraries ("hosts", "dns [!UNAVAIL=return] files");
nss_load_all_libraries ("services", NULL);
/* Disable all uses of NSCD. */
__nss_not_use_nscd_passwd = -1;
__nss_not_use_nscd_group = -1;
__nss_not_use_nscd_hosts = -1;
__nss_not_use_nscd_services = -1;
__nss_not_use_nscd_netgroup = -1;
}
#endif
static void
free_database_entries (name_database_entry *entry)
{
while (entry != NULL)
{
name_database_entry *olde = entry;
service_user *service = entry->service;
while (service != NULL)
{
service_user *olds = service;
if (service->known != NULL)
__tdestroy (service->known, free);
service = service->next;
free (olds);
}
entry = entry->next;
free (olde);
}
}
/* Free all resources if necessary. */
libc_freeres_fn (free_defconfig)
{
name_database_entry *entry = defconfig_entries;
if (entry == NULL)
/* defconfig was not used. */
return;
/* Don't disturb ongoing other threads (if there are any). */
defconfig_entries = NULL;
free_database_entries (entry);
}
libc_freeres_fn (free_mem)
{
name_database *top = service_table;
service_library *library;
if (top == NULL)
/* Maybe we have not read the nsswitch.conf file. */
return;
/* Don't disturb ongoing other threads (if there are any). */
service_table = NULL;
free_database_entries (top->entry);
library = top->library;
while (library != NULL)
{
service_library *oldl = library;
if (library->lib_handle && library->lib_handle != (void *) -1l)
__libc_dlclose (library->lib_handle);
library = library->next;
free (oldl);
}
free (top);
}

69
nss/nsswitch.h
View File

@ -36,6 +36,7 @@ typedef enum
NSS_ACTION_MERGE
} lookup_actions;
struct nss_action;
typedef struct service_library
{
@ -58,42 +59,8 @@ typedef struct
} known_function;
typedef struct service_user
{
/* And the link to the next entry. */
struct service_user *next;
/* Action according to result. */
lookup_actions actions[5];
/* Link to the underlying library object. */
service_library *library;
/* Collection of known functions. */
void *known;
/* Name of the service (`files', `dns', `nis', ...). */
char name[0];
} service_user;
/* To access the action based on the status value use this macro. */
#define nss_next_action(ni, status) ((ni)->actions[2 + status])
typedef struct name_database_entry
{
/* And the link to the next entry. */
struct name_database_entry *next;
/* List of service to be used. */
service_user *service;
/* Name of the database. */
char name[0];
} name_database_entry;
typedef struct name_database
{
/* List of all known databases. */
name_database_entry *entry;
/* List of libraries with service implementation. */
service_library *library;
} name_database;
#define nss_next_action(ni, status) nss_action_get (ni, status)
#ifdef USE_NSCD
@ -127,13 +94,13 @@ extern bool __nss_database_custom[NSS_DBSIDX_max] attribute_hidden;
than one function can use the database. */
extern int __nss_database_lookup2 (const char *database,
const char *alternative_name,
const char *defconfig, service_user **ni);
const char *defconfig, struct nss_action **ni);
libc_hidden_proto (__nss_database_lookup2)
/* Put first function with name FCT_NAME for SERVICE in FCTP. The
position is remembered in NI. The function returns a value < 0 if
an error occurred or no such function exists. */
extern int __nss_lookup (service_user **ni, const char *fct_name,
extern int __nss_lookup (struct nss_action **ni, const char *fct_name,
const char *fct2_name, void **fctp);
libc_hidden_proto (__nss_lookup)
@ -150,16 +117,16 @@ libc_hidden_proto (__nss_lookup)
services. In other words, only if all four lookup results have
the action RETURN associated the lookup process stops before the
natural end. */
extern int __nss_next2 (service_user **ni, const char *fct_name,
extern int __nss_next2 (struct nss_action **ni, const char *fct_name,
const char *fct2_name, void **fctp, int status,
int all_values) attribute_hidden;
libc_hidden_proto (__nss_next2)
extern int __nss_next (service_user **ni, const char *fct_name, void **fctp,
extern int __nss_next (struct nss_action **ni, const char *fct_name, void **fctp,
int status, int all_values);
/* Search for the service described in NI for a function named FCT_NAME
and return a pointer to this function if successful. */
extern void *__nss_lookup_function (service_user *ni, const char *fct_name);
extern void *__nss_lookup_function (struct nss_action *ni, const char *fct_name);
libc_hidden_proto (__nss_lookup_function)
@ -169,7 +136,7 @@ struct traced_file;
extern void __nss_disable_nscd (void (*) (size_t, struct traced_file *));
typedef int (*db_lookup_function) (service_user **, const char *, const char *,
typedef int (*db_lookup_function) (struct nss_action **, const char *, const char *,
void **);
typedef enum nss_status (*setent_function) (int);
typedef enum nss_status (*endent_function) (void);
@ -180,20 +147,20 @@ typedef int (*getent_r_function) (void *, char *, size_t,
extern void __nss_setent (const char *func_name,
db_lookup_function lookup_fct,
service_user **nip, service_user **startp,
service_user **last_nip, int stayon,
struct nss_action **nip, struct nss_action **startp,
struct nss_action **last_nip, int stayon,
int *stayon_tmp, int res)
attribute_hidden;
extern void __nss_endent (const char *func_name,
db_lookup_function lookup_fct,
service_user **nip, service_user **startp,
service_user **last_nip, int res)
struct nss_action **nip, struct nss_action **startp,
struct nss_action **last_nip, int res)
attribute_hidden;
extern int __nss_getent_r (const char *getent_func_name,
const char *setent_func_name,
db_lookup_function lookup_fct,
service_user **nip, service_user **startp,
service_user **last_nip, int *stayon_tmp,
struct nss_action **nip, struct nss_action **startp,
struct nss_action **last_nip, int *stayon_tmp,
int res,
void *resbuf, char *buffer, size_t buflen,
void **result, int *h_errnop)
@ -227,11 +194,15 @@ libc_hidden_proto (__nss_hostname_digits_dots)
/* Prototypes for __nss_*_lookup2 functions. */
#define DEFINE_DATABASE(arg) \
extern service_user *__nss_##arg##_database attribute_hidden; \
int __nss_##arg##_lookup2 (service_user **, const char *, \
extern struct nss_action *__nss_##arg##_database attribute_hidden; \
int __nss_##arg##_lookup2 (struct nss_action **, const char *, \
const char *, void **); \
libc_hidden_proto (__nss_##arg##_lookup2)
#include "databases.def"
#undef DEFINE_DATABASE
#include <nss/nss_module.h>
#include <nss/nss_action.h>
#include <nss/nss_database.h>
#endif /* nsswitch.h */