ldb_tdb.c

samba最新软件

/* 
   ldb database library

   Copyright (C) Andrew Tridgell  2004
   Copyright (C) Stefan Metzmacher  2004
   Copyright (C) Simo Sorce       2006
   

     ** NOTE! The following LGPL license applies to the ldb
     ** library. This does NOT imply that all of Samba is released
     ** under the LGPL
   
   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 3 of the License, or (at your option) any later version.

   This library 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
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/

/*
 *  Name: ldb_tdb
 *
 *  Component: ldb tdb backend
 *
 *  Description: core functions for tdb backend
 *
 *  Author: Andrew Tridgell
 *  Author: Stefan Metzmacher
 *
 *  Modifications:
 *
 *  - description: make the module use asyncronous calls
 *    date: Feb 2006
 *    Author: Simo Sorce
 */

#include "ldb_includes.h"

#include "ldb_tdb.h"


/*
  map a tdb error code to a ldb error code
*/
static int ltdb_err_map(enum TDB_ERROR tdb_code)
{
	switch (tdb_code) {
	case TDB_SUCCESS:
		return LDB_SUCCESS;
	case TDB_ERR_CORRUPT:
	case TDB_ERR_OOM:
	case TDB_ERR_EINVAL:
		return LDB_ERR_OPERATIONS_ERROR;
	case TDB_ERR_IO:
		return LDB_ERR_PROTOCOL_ERROR;
	case TDB_ERR_LOCK:
	case TDB_ERR_NOLOCK:
		return LDB_ERR_BUSY;
	case TDB_ERR_LOCK_TIMEOUT:
		return LDB_ERR_TIME_LIMIT_EXCEEDED;
	case TDB_ERR_EXISTS:
		return LDB_ERR_ENTRY_ALREADY_EXISTS;
	case TDB_ERR_NOEXIST:
		return LDB_ERR_NO_SUCH_OBJECT;
	case TDB_ERR_RDONLY:
		return LDB_ERR_INSUFFICIENT_ACCESS_RIGHTS;
	}
	return LDB_ERR_OTHER;
}


struct ldb_handle *init_ltdb_handle(struct ltdb_private *ltdb, struct ldb_module *module,
				    struct ldb_request *req)
{
	struct ltdb_context *ac;
	struct ldb_handle *h;

	h = talloc_zero(req, struct ldb_handle);
	if (h == NULL) {
		ldb_set_errstring(module->ldb, "Out of Memory");
		return NULL;
	}

	h->module = module;

	ac = talloc_zero(h, struct ltdb_context);
	if (ac == NULL) {
		ldb_set_errstring(module->ldb, "Out of Memory");
		talloc_free(h);
		return NULL;
	}

	h->private_data = (void *)ac;

	h->state = LDB_ASYNC_INIT;
	h->status = LDB_SUCCESS;

	ac->module = module;
	ac->context = req->context;
	ac->callback = req->callback;

	return h;
}

/*
  form a TDB_DATA for a record key
  caller frees

  note that the key for a record can depend on whether the 
  dn refers to a case sensitive index record or not
*/
struct TDB_DATA ltdb_key(struct ldb_module *module, struct ldb_dn *dn)
{
	struct ldb_context *ldb = module->ldb;
	TDB_DATA key;
	char *key_str = NULL;
	const char *dn_folded = NULL;

	/*
	  most DNs are case insensitive. The exception is index DNs for
	  case sensitive attributes

	  there are 3 cases dealt with in this code:

	  1) if the dn doesn't start with @ then uppercase the attribute
             names and the attributes values of case insensitive attributes
	  2) if the dn starts with @ then leave it alone - the indexing code handles
	     the rest
	*/

	dn_folded = ldb_dn_get_casefold(dn);
	if (!dn_folded) {
		goto failed;
	}

	key_str = talloc_strdup(ldb, "DN=");
	if (!key_str) {
		goto failed;
	}

	key_str = talloc_strdup_append_buffer(key_str, dn_folded);
	if (!key_str) {
		goto failed;
	}

	key.dptr = (uint8_t *)key_str;
	key.dsize = strlen(key_str) + 1;

	return key;

failed:
	errno = ENOMEM;
	key.dptr = NULL;
	key.dsize = 0;
	return key;
}

/*
  check special dn's have valid attributes
  currently only @ATTRIBUTES is checked
*/
int ltdb_check_special_dn(struct ldb_module *module, const struct ldb_message *msg)
{
	int i, j;
 
	if (! ldb_dn_is_special(msg->dn) ||
	    ! ldb_dn_check_special(msg->dn, LTDB_ATTRIBUTES)) {
		return 0;
	}

	/* we have @ATTRIBUTES, let's check attributes are fine */
	/* should we check that we deny multivalued attributes ? */
	for (i = 0; i < msg->num_elements; i++) {
		for (j = 0; j < msg->elements[i].num_values; j++) {
			if (ltdb_check_at_attributes_values(&msg->elements[i].values[j]) != 0) {
				ldb_set_errstring(module->ldb, "Invalid attribute value in an @ATTRIBUTES entry");
				return LDB_ERR_INVALID_ATTRIBUTE_SYNTAX;
			}
		}
	}

	return 0;
}


/*
  we've made a modification to a dn - possibly reindex and 
  update sequence number
*/
static int ltdb_modified(struct ldb_module *module, struct ldb_dn *dn)
{
	int ret = LDB_SUCCESS;

	if (ldb_dn_is_special(dn) &&
	    (ldb_dn_check_special(dn, LTDB_INDEXLIST) ||
	     ldb_dn_check_special(dn, LTDB_ATTRIBUTES)) ) {
		ret = ltdb_reindex(module);
	}

	if (ret == LDB_SUCCESS &&
	    !(ldb_dn_is_special(dn) &&
	      ldb_dn_check_special(dn, LTDB_BASEINFO)) ) {
		ret = ltdb_increase_sequence_number(module);
	}

	return ret;
}

/*
  store a record into the db
*/
int ltdb_store(struct ldb_module *module, const struct ldb_message *msg, int flgs)
{
	struct ltdb_private *ltdb =
		talloc_get_type(module->private_data, struct ltdb_private);
	TDB_DATA tdb_key, tdb_data;
	int ret;

	tdb_key = ltdb_key(module, msg->dn);
	if (!tdb_key.dptr) {
		return LDB_ERR_OTHER;
	}

	ret = ltdb_pack_data(module, msg, &tdb_data);
	if (ret == -1) {
		talloc_free(tdb_key.dptr);
		return LDB_ERR_OTHER;
	}

	ret = tdb_store(ltdb->tdb, tdb_key, tdb_data, flgs);
	if (ret == -1) {
		ret = ltdb_err_map(tdb_error(ltdb->tdb));
		goto done;
	}
	
	ret = ltdb_index_add(module, msg);
	if (ret != LDB_SUCCESS) {
		tdb_delete(ltdb->tdb, tdb_key);
	}

done:
	talloc_free(tdb_key.dptr);
	talloc_free(tdb_data.dptr);

	return ret;
}


static int ltdb_add_internal(struct ldb_module *module, const struct ldb_message *msg)
{
	int ret;
	
	ret = ltdb_check_special_dn(module, msg);
	if (ret != LDB_SUCCESS) {
		return ret;
	}
	
	if (ltdb_cache_load(module) != 0) {
		return LDB_ERR_OPERATIONS_ERROR;
	}

	ret = ltdb_store(module, msg, TDB_INSERT);

	if (ret == LDB_ERR_ENTRY_ALREADY_EXISTS) {
		ldb_asprintf_errstring(module->ldb, "Entry %s already exists", ldb_dn_get_linearized(msg->dn));
		return ret;
	}
	
	if (ret == LDB_SUCCESS) {
		ret = ltdb_index_one(module, msg, 1);
		if (ret != LDB_SUCCESS) {
			return ret;
		}

		ret = ltdb_modified(module, msg->dn);
		if (ret != LDB_SUCCESS) {
			return ret;
		}
	}

	return ret;
}

/*
  add a record to the database
*/
static int ltdb_add(struct ldb_module *module, struct ldb_request *req)
{
	struct ltdb_private *ltdb = talloc_get_type(module->private_data, struct ltdb_private);
	struct ltdb_context *ltdb_ac;
	int tret, ret = LDB_SUCCESS;

	if (check_critical_controls(req->controls)) {
		return LDB_ERR_UNSUPPORTED_CRITICAL_EXTENSION;
	}
	
	req->handle = init_ltdb_handle(ltdb, module, req);
	if (req->handle == NULL) {
		return LDB_ERR_OPERATIONS_ERROR;
	}
	ltdb_ac = talloc_get_type(req->handle->private_data, struct ltdb_context);

	tret = ltdb_add_internal(module, req->op.add.message);
	if (tret != LDB_SUCCESS) {
		req->handle->status = tret;
		goto done;
	}
	
	if (ltdb_ac->callback) {
		ret = ltdb_ac->callback(module->ldb, ltdb_ac->context, NULL);
	}
done:
	req->handle->state = LDB_ASYNC_DONE;
	return ret;
}

/*
  delete a record from the database, not updating indexes (used for deleting
  index records)
*/
int ltdb_delete_noindex(struct ldb_module *module, struct ldb_dn *dn)
{
	struct ltdb_private *ltdb =
		talloc_get_type(module->private_data, struct ltdb_private);
	TDB_DATA tdb_key;
	int ret;

	tdb_key = ltdb_key(module, dn);
	if (!tdb_key.dptr) {
		return LDB_ERR_OTHER;
	}

	ret = tdb_delete(ltdb->tdb, tdb_key);
	talloc_free(tdb_key.dptr);

	if (ret != 0) {
		ret = ltdb_err_map(tdb_error(ltdb->tdb));
	}

	return ret;
}

static int ltdb_delete_internal(struct ldb_module *module, struct ldb_dn *dn)
{
	struct ldb_message *msg;
	int ret;

	msg = talloc(module, struct ldb_message);
	if (msg == NULL) {
		return LDB_ERR_OPERATIONS_ERROR;
	}

	/* in case any attribute of the message was indexed, we need
	   to fetch the old record */
	ret = ltdb_search_dn1(module, dn, msg);
	if (ret != LDB_SUCCESS) {
		/* not finding the old record is an error */
		goto done;
	}

	ret = ltdb_delete_noindex(module, dn);
	if (ret != LDB_SUCCESS) {
		goto done;
	}

	/* remove one level attribute */
	ret = ltdb_index_one(module, msg, 0);
	if (ret != LDB_SUCCESS) {
		goto done;
	}

	/* remove any indexed attributes */
	ret = ltdb_index_del(module, msg);
	if (ret != LDB_SUCCESS) {
		goto done;
	}

	ret = ltdb_modified(module, dn);
	if (ret != LDB_SUCCESS) {
		goto done;
	}

done:
	talloc_free(msg);
	return ret;
}

/*
  delete a record from the database
*/
static int ltdb_delete(struct ldb_module *module, struct ldb_request *req)
{
	struct ltdb_private *ltdb = talloc_get_type(module->private_data, struct ltdb_private);
	struct ltdb_context *ltdb_ac;
	int tret, ret = LDB_SUCCESS;

	if (check_critical_controls(req->controls)) {
		return LDB_ERR_UNSUPPORTED_CRITICAL_EXTENSION;
	}
	
	req->handle = NULL;

	if (ltdb_cache_load(module) != 0) {
		return LDB_ERR_OPERATIONS_ERROR;
	}

	req->handle = init_ltdb_handle(ltdb, module, req);
	if (req->handle == NULL) {
		return LDB_ERR_OPERATIONS_ERROR;
	}
	ltdb_ac = talloc_get_type(req->handle->private_data, struct ltdb_context);

	tret = ltdb_delete_internal(module, req->op.del.dn);
	if (tret != LDB_SUCCESS) {
		req->handle->status = tret; 
		goto done;
	}

	if (ltdb_ac->callback) {
		ret = ltdb_ac->callback(module->ldb, ltdb_ac->context, NULL);
	}
done:
	req->handle->state = LDB_ASYNC_DONE;
	return ret;
}

/*
  find an element by attribute name. At the moment this does a linear search, it should
  be re-coded to use a binary search once all places that modify records guarantee
  sorted order

  return the index of the first matching element if found, otherwise -1
*/
static int find_element(const struct ldb_message *msg, const char *name)
{
	unsigned int i;
	for (i=0;i<msg->num_elements;i++) {
		if (ldb_attr_cmp(msg->elements[i].name, name) == 0) {
			return i;
		}
	}
	return -1;
}


/*
  add an element to an existing record. Assumes a elements array that we
  can call re-alloc on, and assumed that we can re-use the data pointers from the 
  passed in additional values. Use with care!

  returns 0 on success, -1 on failure (and sets errno)
*/
static int msg_add_element(struct ldb_context *ldb,
			   struct ldb_message *msg, struct ldb_message_element *el)
{
	struct ldb_message_element *e2;
	unsigned int i;

	e2 = talloc_realloc(msg, msg->elements, struct ldb_message_element, 
			      msg->num_elements+1);
	if (!e2) {
		errno = ENOMEM;
		return -1;
	}

	msg->elements = e2;

	e2 = &msg->elements[msg->num_elements];

	e2->name = el->name;
	e2->flags = el->flags;
	e2->values = NULL;
	if (el->num_values != 0) {
		e2->values = talloc_array(msg->elements, struct ldb_val, el->num_values);
		if (!e2->values) {
			errno = ENOMEM;
			return -1;
		}
	}
	for (i=0;i<el->num_values;i++) {
		e2->values[i] = el->values[i];
	}
	e2->num_values = el->num_values;

	msg->num_elements++;

	return 0;
}

/*
  delete all elements having a specified attribute name
*/
static int msg_delete_attribute(struct ldb_module *module,
				struct ldb_context *ldb,
				struct ldb_message *msg, const char *name)
{
	const char *dn;
	unsigned int i, j;

	dn = ldb_dn_get_linearized(msg->dn);
	if (dn == NULL) {
		return -1;
	}

	for (i=0;i<msg->num_elements;i++) {
		if (ldb_attr_cmp(msg->elements[i].name, name) == 0) {
			for (j=0;j<msg->elements[i].num_values;j++) {
				ltdb_index_del_value(module, dn, &msg->elements[i], j);
			}
			talloc_free(msg->elements[i].values);
			if (msg->num_elements > (i+1)) {
				memmove(&msg->elements[i], 
					&msg->elements[i+1], 
					sizeof(struct ldb_message_element)*
					(msg->num_elements - (i+1)));
			}
			msg->num_elements--;
			i--;
			msg->elements = talloc_realloc(msg, msg->elements, 
							 struct ldb_message_element, 
							 msg->num_elements);
		}
	}

	return 0;
}

/*
  delete all elements matching an attribute name/value 

  return 0 on success, -1 on failure
*/
static int msg_delete_element(struct ldb_module *module,
			      struct ldb_message *msg, 
			      const char *name,
			      const struct ldb_val *val)
{
	struct ldb_context *ldb = module->ldb;
	unsigned int i;
	int found;
	struct ldb_message_element *el;
	const struct ldb_schema_attribute *a;

	found = find_element(msg, name);
	if (found == -1) {
		return -1;
	}

	el = &msg->elements[found];