aboutsummaryrefslogtreecommitdiff
path: root/nss/nss_db/db-open.c
diff options
context:
space:
mode:
authorUlrich Drepper <drepper@gmail.com>2011-06-14 22:21:51 -0400
committerUlrich Drepper <drepper@gmail.com>2011-06-15 21:06:18 -0400
commit2666d441c2d8107b1987b869714189af64b954c6 (patch)
treec7b8877d691db280202b4c7655907a1165ec84fc /nss/nss_db/db-open.c
parent9ee76b5ae861ff9891e5586fc6906c94c447a9e0 (diff)
downloadglibc-2666d441c2d8107b1987b869714189af64b954c6.tar
glibc-2666d441c2d8107b1987b869714189af64b954c6.tar.gz
glibc-2666d441c2d8107b1987b869714189af64b954c6.tar.bz2
glibc-2666d441c2d8107b1987b869714189af64b954c6.zip
Reenable nss_db with a completely new implementation
No longer is Berkeley db used. Instead a simple hash function is used. The database files are not updated once they are created and therefore no complicated database is needed.
Diffstat (limited to 'nss/nss_db/db-open.c')
-rw-r--r--nss/nss_db/db-open.c377
1 files changed, 30 insertions, 347 deletions
diff --git a/nss/nss_db/db-open.c b/nss/nss_db/db-open.c
index 94dfe5b7da..36ce494d02 100644
--- a/nss/nss_db/db-open.c
+++ b/nss/nss_db/db-open.c
@@ -1,5 +1,5 @@
/* Common database routines for nss_db.
- Copyright (C) 2000 Free Software Foundation, Inc.
+ Copyright (C) 2000, 2011 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
@@ -22,368 +22,51 @@
#include <dlfcn.h>
#include <stdlib.h>
#include <string.h>
-#include <bits/libc-lock.h>
+#include <sys/mman.h>
+#include <not-cancel.h>
-#include "dummy-db.h"
+#include <kernel-features.h>
#include "nss_db.h"
-/* This file contains the functions used to open and close the databases
- read by the rest of libnss_db. Not all of them are thread safe;
- make sure the caller does the appropriate locking.
-
- We dynamically load the database library, so that it does not have
- to be present when glibc is compiled. Once loaded, the database
- library is never never unloaded again until the libnss_db module is
- unloaded (from the free_mem routine in nsswitch.c) -- we catch the
- unload by providing a shlib destructor. (XXX Does that actually
- work?) */
-
-/* Handle for the shared Berkeley DB library. If non-null, the
- database library is completely loaded and ready to be used by
- multithreaded code. */
-static void *libdb_handle;
-
-/* The version of the Berkeley DB library we are using. */
-enum {
- nodb,
- db24,
- db27,
- db30
-} libdb_version;
-
-/* Pointer to the db_open function. For use with DB 2.x. */
-static int (*libdb_db_open) (const char *, int,
- uint32_t, int, void *, void *, void **);
-
-/* Pointer to the db_create function. For use with DB 3.x. */
-static int (*libdb_db_create) (void *, void *, uint32_t);
-
-/* Constants which vary from version to version are actually variables
- here. */
-int db_first;
-int db_next;
-int db_nooverwrite;
-int db_truncate;
-int db_rdonly;
-/* Variables which keep track of the error values. */
-int db_keyexist;
-int db_notfound;
-
-/* Locks the static variables in this file. */
-__libc_lock_define_initialized (static, lock)
-
-/* Dynamically load the database library. Return zero if successful,
- non-zero if no suitable version of the library could be loaded.
- Must be called with the above lock held if it might run in a
- multithreaded context.
-
- We try currently:
- - libdb.so.3: the name used by glibc 2.1
- - libdb-3.0.so: the name used by db-3.0.x
- and maybe others in the future. */
-
+/* Open the database stored in FILE. If succesful, store either a
+ pointer to the mapped file or a file handle for the file in H and
+ return NSS_STATUS_SUCCESS. On failure, return the appropriate
+ lookup status. */
enum nss_status
-load_db (void)
-{
- static const char *libnames[] = { "libdb.so.3", "libdb-3.0.so" };
- int x;
-
- for (x = 0; x < sizeof (libnames) / sizeof (libnames[0]); ++x)
- {
- libdb_handle = dlopen (libnames[x], RTLD_LAZY);
- if (libdb_handle == NULL)
- continue;
-
- /* DB 3.0 has db_create instead of db_open. */
- libdb_db_create = dlsym (libdb_handle, "db_create");
-
- if (libdb_db_create == NULL)
- /* DB 2.x uses db_open. */
- libdb_db_open = dlsym (libdb_handle, "db_open");
-
- if (libdb_db_open != NULL || libdb_db_create != NULL)
- {
- /* Alright, we got a library. Now find out which version it is. */
- const char *(*db_version) (int *, int *, int *);
-
- db_version = dlsym (libdb_handle, "db_version");
- if (db_version != NULL)
- {
- /* Call the function and get the information. */
- int major, minor, subminor;
-
- DL_CALL_FCT (db_version, (&major, &minor, &subminor));
- switch (major)
- {
- case 2:
- /* Sanity check: Do we have db_open? */
- if (libdb_db_open != NULL)
- {
- if (minor < 6 || (minor == 6 && subminor < 4))
- {
- libdb_version = db24;
- db_first = DB24_FIRST;
- db_next = DB24_NEXT;
- db_nooverwrite = DB24_NOOVERWRITE;
- db_truncate = DB24_TRUNCATE;
- }
- else
- {
- libdb_version = db27;
- db_first = DB27_FIRST;
- db_next = DB27_NEXT;
- db_nooverwrite = DB27_NOOVERWRITE;
- db_truncate = DB27_TRUNCATE;
- }
- db_keyexist = DB2x_KEYEXIST;
- db_notfound = DB2x_NOTFOUND;
- db_rdonly = DB2x_RDONLY;
- }
- break;
-
- case 3:
- /* Sanity check: Do we have db_create? */
- if (libdb_db_create != NULL)
- {
- libdb_version = db30;
- db_first = DB30_FIRST;
- db_next = DB30_NEXT;
- db_keyexist = DB30_KEYEXIST;
- db_notfound = DB30_NOTFOUND;
- db_rdonly = DB30_RDONLY;
- }
- break;
-
- default:
- break;
- }
- }
-
- if (libdb_version != nodb)
- return NSS_STATUS_SUCCESS;
-
- /* Clear variables. */
- libdb_db_open = NULL;
- libdb_db_create = NULL;
- }
-
- dlclose (libdb_handle);
- }
-
- (void) dlerror ();
- return NSS_STATUS_UNAVAIL;
-}
-
-/* Set the `FD_CLOEXEC' flag of FD. Return 0 on success, or -1 on
- error with `errno' set. */
-static int
-set_cloexec_flag (int fd)
+internal_setent (const char *file, struct nss_db_map *mapping)
{
- int oldflags = fcntl (fd, F_GETFD, 0);
-
- if (oldflags < 0)
- return oldflags;
-
- oldflags |= FD_CLOEXEC;
-
- return fcntl (fd, F_SETFD, oldflags);
-}
-
-/* Make sure we don't use the library anymore once we are shutting down. */
-static void __attribute__ ((destructor))
-unload_db (void)
-{
- if (libdb_handle != NULL)
+ enum nss_status status = NSS_STATUS_UNAVAIL;
+
+ int mode = O_RDONLY | O_LARGEFILE;
+#ifdef O_CLOEXEC
+ mode |= O_CLOEXEC;
+#endif
+ int fd = open_not_cancel_2 (file, mode);
+ if (fd != -1)
{
- libdb_db_open = NULL;
- libdb_db_create = NULL;
- libdb_version = nodb;
- dlclose (libdb_handle);
- }
-}
-
-/* Open the database stored in FILE. If succesful, store the database
- handle in *DBP and return NSS_STATUS_SUCCESS. On failure, return
- the appropriate lookup status. */
-enum nss_status
-internal_setent (const char *file, NSS_DB **dbp)
-{
- enum nss_status status = NSS_STATUS_SUCCESS;
+ struct nss_db_header header;
- if (*dbp == NULL)
- {
- if (libdb_db_open == NULL && libdb_db_create == NULL)
+ if (read (fd, &header, sizeof (header)) == sizeof (header))
{
- __libc_lock_lock (lock);
-
- if (libdb_db_open == NULL && libdb_db_create == NULL)
- status = load_db ();
-
- __libc_lock_unlock (lock);
+ mapping->header = mmap (NULL, header.allocate, PROT_READ,
+ MAP_PRIVATE, fd, 0);
+ mapping->len = header.allocate;
+ if (mapping->header != MAP_FAILED)
+ status = NSS_STATUS_SUCCESS;
+ else if (errno == ENOMEM)
+ status = NSS_STATUS_TRYAGAIN;
}
- if (status == NSS_STATUS_SUCCESS)
- status = dbopen (file, db_rdonly, 0, dbp);
+ close_not_cancel_no_status (fd);
}
return status;
}
-/* Close the database *DBP. */
+/* Close the database. */
void
-internal_endent (NSS_DB **dbp)
-{
- NSS_DB *db = *dbp;
-
- if (db != NULL)
- {
- DL_CALL_FCT (db->close, (db->db, 0));
- *dbp = NULL;
- }
-}
-
-/* Allocate a cursor for database DB and transaction TXN. On success,
- store the cursor in *DBCP and return zero. Otherwise return an
- error value. */
-int
-db_cursor (void *db, void *txn, NSS_DBC **dbcp)
-{
- NSS_DBC *dbc;
- int ret;
-
- dbc = (NSS_DBC *) malloc (sizeof (NSS_DBC));
- if (dbc == NULL)
- return ENOMEM;
-
- switch (libdb_version)
- {
- case db24:
- ret = ((struct db24 *) db)->cursor (db, txn, &dbc->cursor);
-
- if (ret == 0)
- dbc->c_get = ((struct dbc24 *) dbc->cursor)->c_get;
- break;
-
- case db27:
- ret = ((struct db27 *) db)->cursor (db, txn, &dbc->cursor, 0);
-
- if (ret == 0)
- dbc->c_get = ((struct dbc27 *) dbc->cursor)->c_get;
- break;
-
- case db30:
- ret = ((struct db30 *) db)->cursor (db, txn, &dbc->cursor, 0);
-
- if (ret == 0)
- dbc->c_get = ((struct dbc30 *) dbc->cursor)->c_get;
- break;
-
- default:
- abort ();
- }
-
- if (ret != 0)
- {
- free (dbc);
- return ret;
- }
-
- *dbcp = dbc;
-
- return 0;
-}
-
-
-/* Open the database in FNAME, for access specified by FLAGS. If
- opening the database causes the file FNAME to be created, it is
- created with MODE. If succesful, store the database handle in *DBP
- and return NSS_STATUS_SUCCESS. On failure, return the appropriate
- lookup status. */
-int
-dbopen (const char *fname, int oper, int mode, NSS_DB **dbp)
+internal_endent (struct nss_db_map *mapping)
{
- int err;
- int fd;
- NSS_DB *db;
-
- /* Construct the object we pass up. */
- db = (NSS_DB *) calloc (1, sizeof (NSS_DB));
- if (db == NULL)
- return NSS_STATUS_UNAVAIL;
-
- /* Initialize the object. */
- db->cursor = db_cursor;
-
- /* Actually open the database. */
- switch (libdb_version)
- {
- case db24:
- case db27:
- err = DL_CALL_FCT (libdb_db_open,
- (fname, DB_BTREE, oper, mode, NULL, NULL, &db->db));
- if (err != 0)
- goto fail;
-
- if (libdb_version)
- {
- db->close = ((struct db24 *) db->db)->close;
- db->fd = ((struct db24 *) db->db)->fd;
- db->get = ((struct db24 *) db->db)->get;
- db->put = ((struct db24 *) db->db)->put;
- }
- else
- {
- db->close = ((struct db27 *) db->db)->close;
- db->fd = ((struct db27 *) db->db)->fd;
- db->get = ((struct db27 *) db->db)->get;
- db->put = ((struct db27 *) db->db)->put;
- }
- break;
-
- case db30:
- err = DL_CALL_FCT (libdb_db_create, (db->db, NULL, 0));
- if (err != 0)
- goto fail;
-
- db->close = ((struct db30 *) db->db)->close;
- db->fd = ((struct db30 *) db->db)->fd;
- db->get = ((struct db30 *) db->db)->get;
- db->put = ((struct db30 *) db->db)->put;
-
- err = ((struct db30 *) db->db)->open (db->db, fname, NULL, DB_BTREE,
- oper, mode);
- if (err != 0)
- goto fail;
- break;
-
- default:
- abort ();
- }
-
- /* We have to make sure the file is `closed on exec'. */
- err = DL_CALL_FCT (db->fd, (db->db, &fd));
- if (err != 0)
- goto fail;
- if (set_cloexec_flag (fd) < 0)
- goto fail;
-
- *dbp = db;
-
- return NSS_STATUS_UNAVAIL;
-
- fail:
- /* Something went wrong. Close the database if necessary. */
- if (db)
- {
- if (db->db && db->close)
- DL_CALL_FCT (db->close, (db->db, 0));
- free (db);
- }
-
- /* Make sure `errno' is set. */
- if (err)
- __set_errno (err);
-
- return err == EAGAIN ? NSS_STATUS_TRYAGAIN : NSS_STATUS_UNAVAIL;
+ munmap (mapping->header, mapping->len);
}