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samba-mirror/source4/lib/ldb-samba/ldb_wrap.c

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/*
Unix SMB/CIFS implementation.
LDB wrap functions
Copyright (C) Andrew Tridgell 2004-2009
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/*
the stupidity of the unix fcntl locking design forces us to never
allow a database file to be opened twice in the same process. These
wrappers provide convenient access to a tdb or ldb, taking advantage
of talloc destructors to ensure that only a single open is done
*/
#include "includes.h"
#include "lib/events/events.h"
#include <ldb.h>
#include <ldb_errors.h>
#include "lib/ldb-samba/ldif_handlers.h"
#include "ldb_wrap.h"
#include "dsdb/samdb/samdb.h"
#include "param/param.h"
#include "../lib/util/dlinklist.h"
#include <tdb.h>
/*
this is used to catch debug messages from ldb
*/
static void ldb_wrap_debug(void *context, enum ldb_debug_level level,
const char *fmt, va_list ap) PRINTF_ATTRIBUTE(3,0);
static void ldb_wrap_debug(void *context, enum ldb_debug_level level,
const char *fmt, va_list ap)
{
int samba_level = -1;
char *s = NULL;
switch (level) {
case LDB_DEBUG_FATAL:
samba_level = 0;
break;
case LDB_DEBUG_ERROR:
samba_level = 1;
break;
case LDB_DEBUG_WARNING:
samba_level = 2;
break;
case LDB_DEBUG_TRACE:
samba_level = 5;
break;
};
vasprintf(&s, fmt, ap);
if (!s) return;
DEBUG(samba_level, ("ldb: %s\n", s));
free(s);
}
/*
connecting to a ldb can be a relatively expensive operation because
of the schema and partition loads. We keep a list of open ldb
contexts here, and try to re-use when possible.
This means callers of ldb_wrap_connect() must use talloc_unlink() or
the free of a parent to destroy the context
*/
static struct ldb_wrap {
struct ldb_wrap *next, *prev;
struct ldb_wrap_context {
/* the context is what we use to tell if two ldb
* connections are exactly equivalent
*/
const char *url;
struct tevent_context *ev;
struct loadparm_context *lp_ctx;
struct auth_session_info *session_info;
struct cli_credentials *credentials;
unsigned int flags;
} context;
struct ldb_context *ldb;
} *ldb_wrap_list;
/*
free a ldb_wrap structure
*/
static int ldb_wrap_destructor(struct ldb_wrap *w)
{
DLIST_REMOVE(ldb_wrap_list, w);
return 0;
}
/*
* The casefolder for s4's LDB databases - Unicode-safe
*/
char *wrap_casefold(void *context, void *mem_ctx, const char *s, size_t n)
{
return strupper_talloc_n(mem_ctx, s, n);
}
struct ldb_context *samba_ldb_init(TALLOC_CTX *mem_ctx,
struct tevent_context *ev,
struct loadparm_context *lp_ctx,
struct auth_session_info *session_info,
struct cli_credentials *credentials)
{
struct ldb_context *ldb;
int ret;
ldb = ldb_init(mem_ctx, ev);
if (ldb == NULL) {
return NULL;
}
ldb_set_modules_dir(ldb,
talloc_asprintf(ldb,
"%s/ldb",
lpcfg_modulesdir(lp_ctx)));
ldb_set_debug(ldb, ldb_wrap_debug, NULL);
ldb_set_utf8_fns(ldb, NULL, wrap_casefold);
if (session_info) {
if (ldb_set_opaque(ldb, "sessionInfo", session_info)) {
talloc_free(ldb);
return NULL;
}
}
if (credentials) {
if (ldb_set_opaque(ldb, "credentials", credentials)) {
talloc_free(ldb);
return NULL;
}
}
if (ldb_set_opaque(ldb, "loadparm", lp_ctx)) {
talloc_free(ldb);
return NULL;
}
/* This must be done before we load the schema, as these
* handlers for objectSid and objectGUID etc must take
* precedence over the 'binary attribute' declaration in the
* schema */
ret = ldb_register_samba_handlers(ldb);
if (ret != LDB_SUCCESS) {
talloc_free(ldb);
return NULL;
}
/* we usually want Samba databases to be private. If we later
find we need one public, we will need to add a parameter to
ldb_wrap_connect() */
ldb_set_create_perms(ldb, 0600);
return ldb;
}
struct ldb_context *ldb_wrap_find(const char *url,
struct tevent_context *ev,
struct loadparm_context *lp_ctx,
struct auth_session_info *session_info,
struct cli_credentials *credentials,
int flags)
{
struct ldb_wrap *w;
/* see if we can re-use an existing ldb */
for (w=ldb_wrap_list; w; w=w->next) {
if (w->context.ev == ev &&
w->context.lp_ctx == lp_ctx &&
w->context.session_info == session_info &&
w->context.credentials == credentials &&
w->context.flags == flags &&
(w->context.url == url || strcmp(w->context.url, url) == 0))
return w->ldb;
}
return NULL;
}
int samba_ldb_connect(struct ldb_context *ldb, struct loadparm_context *lp_ctx,
const char *url, int flags)
{
int ret;
char *real_url = NULL;
/* allow admins to force non-sync ldb for all databases */
if (lpcfg_parm_bool(lp_ctx, NULL, "ldb", "nosync", false)) {
flags |= LDB_FLG_NOSYNC;
}
if (DEBUGLVL(10)) {
flags |= LDB_FLG_ENABLE_TRACING;
}
real_url = private_path(ldb, lp_ctx, url);
if (real_url == NULL) {
return LDB_ERR_OPERATIONS_ERROR;
}
ret = ldb_connect(ldb, real_url, flags, NULL);
if (ret != LDB_SUCCESS) {
return ret;
}
/* setup for leak detection */
ldb_set_opaque(ldb, "wrap_url", real_url);
return LDB_SUCCESS;
}
bool ldb_wrap_add(const char *url, struct tevent_context *ev,
struct loadparm_context *lp_ctx,
struct auth_session_info *session_info,
struct cli_credentials *credentials,
int flags,
struct ldb_context *ldb)
{
struct ldb_wrap *w;
struct ldb_wrap_context c;
/* add to the list of open ldb contexts */
w = talloc(ldb, struct ldb_wrap);
if (w == NULL) {
return false;
}
c.url = url;
c.ev = ev;
c.lp_ctx = lp_ctx;
c.session_info = session_info;
c.credentials = credentials;
c.flags = flags;
w->context = c;
w->context.url = talloc_strdup(w, url);
if (w->context.url == NULL) {
return false;
}
if (session_info) {
/* take a reference to the session_info, as it is
* possible for the ldb to live longer than the
* session_info. This happens when a DRS DsBind call
* reuses a handle, but the original connection is
* shutdown. The token for the new connection is still
* valid, so we need the session_info to remain valid for
* ldb modules to use
*/
if (talloc_reference(w, session_info) == NULL) {
return false;
}
}
w->ldb = ldb;
DLIST_ADD(ldb_wrap_list, w);
talloc_set_destructor(w, ldb_wrap_destructor);
return true;
}
/*
wrapped connection to a ldb database
to close just talloc_free() the returned ldb_context
TODO: We need an error_string parameter
*/
struct ldb_context *ldb_wrap_connect(TALLOC_CTX *mem_ctx,
struct tevent_context *ev,
struct loadparm_context *lp_ctx,
const char *url,
struct auth_session_info *session_info,
struct cli_credentials *credentials,
unsigned int flags)
{
struct ldb_context *ldb;
int ret;
ldb = ldb_wrap_find(url, ev, lp_ctx, session_info, credentials, flags);
if (ldb != NULL)
return talloc_reference(mem_ctx, ldb);
ldb = samba_ldb_init(mem_ctx, ev, lp_ctx, session_info, credentials);
if (ldb == NULL)
return NULL;
ret = samba_ldb_connect(ldb, lp_ctx, url, flags);
if (ret != LDB_SUCCESS) {
talloc_free(ldb);
return NULL;
}
if (!ldb_wrap_add(url, ev, lp_ctx, session_info, credentials, flags, ldb)) {
talloc_free(ldb);
return NULL;
}
DEBUG(3,("ldb_wrap open of %s\n", url));
return ldb;
}
/*
when we fork() we need to make sure that any open ldb contexts have
any open transactions cancelled
*/
void ldb_wrap_fork_hook(void)
{
struct ldb_wrap *w;
for (w=ldb_wrap_list; w; w=w->next) {
if (ldb_transaction_cancel_noerr(w->ldb) != LDB_SUCCESS) {
smb_panic("Failed to cancel child transactions\n");
}
}
if (tdb_reopen_all(1) == -1) {
smb_panic("tdb_reopen_all failed\n");
}
}
char *ldb_relative_path(struct ldb_context *ldb,
TALLOC_CTX *mem_ctx,
const char *name)
{
const char *base_url =
(const char *)ldb_get_opaque(ldb, "ldb_url");
char *path, *p, *full_name;
if (name == NULL) {
return NULL;
}
if (strncmp("tdb://", base_url, 6) == 0) {
base_url = base_url+6;
}
path = talloc_strdup(mem_ctx, base_url);
if (path == NULL) {
return NULL;
}
if ( (p = strrchr(path, '/')) != NULL) {
p[0] = '\0';
full_name = talloc_asprintf(mem_ctx, "%s/%s", path, name);
} else {
full_name = talloc_asprintf(mem_ctx, "./%s", name);
}
talloc_free(path);
return full_name;
}