mirror of
https://sourceware.org/git/glibc.git
synced 2025-07-28 00:21:52 +03:00
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.
This commit is contained in:
@ -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)
|
||||
internal_setent (const char *file, struct nss_db_map *mapping)
|
||||
{
|
||||
static const char *libnames[] = { "libdb.so.3", "libdb-3.0.so" };
|
||||
int x;
|
||||
enum nss_status status = NSS_STATUS_UNAVAIL;
|
||||
|
||||
for (x = 0; x < sizeof (libnames) / sizeof (libnames[0]); ++x)
|
||||
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_handle = dlopen (libnames[x], RTLD_LAZY);
|
||||
if (libdb_handle == NULL)
|
||||
continue;
|
||||
struct nss_db_header header;
|
||||
|
||||
/* 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)
|
||||
if (read (fd, &header, sizeof (header)) == sizeof (header))
|
||||
{
|
||||
/* 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;
|
||||
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;
|
||||
}
|
||||
|
||||
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)
|
||||
{
|
||||
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)
|
||||
{
|
||||
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;
|
||||
|
||||
if (*dbp == NULL)
|
||||
{
|
||||
if (libdb_db_open == NULL && libdb_db_create == NULL)
|
||||
{
|
||||
__libc_lock_lock (lock);
|
||||
|
||||
if (libdb_db_open == NULL && libdb_db_create == NULL)
|
||||
status = load_db ();
|
||||
|
||||
__libc_lock_unlock (lock);
|
||||
}
|
||||
|
||||
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)
|
||||
internal_endent (struct nss_db_map *mapping)
|
||||
{
|
||||
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)
|
||||
{
|
||||
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);
|
||||
}
|
||||
|
Reference in New Issue
Block a user