s3:groupmap revert to tdb storage

Group mapping needs to be cluster aware, and this means using the tdb backend.
Remove ldb group mapping as this is not cluster aware.

3 files changed, 268 insertions, 732 deletions

diff --git a/source3/groupdb/mapping.c b/source3/groupdb/mapping.c
index 579486b874..b648c58202 100644
--- a/source3/groupdb/mapping.c
+++ b/source3/groupdb/mapping.c
@@ -30,30 +30,12 @@ static const struct mapping_backend *backend;
  */
 static bool init_group_mapping(void)
 {
-	const char *backend_string;
-
 	if (backend != NULL) {
 		/* already initialised */
 		return True;
 	}
 
-	/*
-	 * default to using the ldb backend. This parameter should
-	 * disappear in future versions of Samba3.
-	 *
-	 * But it's needed for cluster setups, because it's
-	 * not yet possible to distribute a ldb inside a cluster.
-	 */
-	backend_string = lp_parm_const_string(-1, "groupdb", "backend", "ldb");
-
-	if (strcmp(backend_string, "ldb") == 0) {
-		backend = groupdb_ldb_init();
-	} else if (strcmp(backend_string, "tdb") == 0) {
-		backend = groupdb_tdb_init();
-	} else {
-		DEBUG(0,("Unknown groupdb backend '%s'\n", backend_string));
-		smb_panic("Unknown groupdb backend");
-	}
+        backend = groupdb_tdb_init();
 
 	return backend != NULL;
 }
diff --git a/source3/groupdb/mapping_ldb.c b/source3/groupdb/mapping_ldb.c
deleted file mode 100644
index 89966e1986..0000000000
--- a/source3/groupdb/mapping_ldb.c
+++ /dev/null
@@ -1,701 +0,0 @@
-/* 
- *  Unix SMB/CIFS implementation.
- *
- *  group mapping code on top of ldb
- *
- *  Copyright (C) Andrew Tridgell              2006
- *
- * based on tdb group mapping code from groupdb/mapping.c
- *  
- *  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/>.
- */
-
-#include "includes.h"
-#include "groupdb/mapping.h"
-#include "lib/ldb/include/ldb.h"
-#include "lib/ldb/include/ldb_errors.h"
-
-static struct ldb_context *ldb;
-
-static bool mapping_upgrade(const char *tdb_path);
-
-/*
-  connect to the group mapping ldb
-*/
-static bool init_group_mapping(void)
-{
-	bool existed;
-	const char *init_ldif[] = 
-		{ "dn: @ATTRIBUTES\n" \
-		  "ntName: CASE_INSENSITIVE\n" \
-		  "\n",
-		  "dn: @INDEXLIST\n" \
-		  "@IDXATTR: gidNumber\n" \
-		  "@IDXATTR: ntName\n" \
-		  "@IDXATTR: member\n" };
-	const char *db_path, *tdb_path;
-	int ret;
-	int flags = 0;
-
-	if (ldb != NULL) {
-		return True;
-	}
-
-	/* this is needed as Samba3 doesn't have this globally yet */
-	ldb_global_init();
-
-	db_path = state_path("group_mapping.ldb");
-
-	ldb = ldb_init(NULL, NULL);
-	if (ldb == NULL) goto failed;
-
-	/* Ensure this db is created read/write for root only. */
-	ldb_set_create_perms(ldb, 0600);
-
-	existed = file_exist(db_path);
-
-	if (lp_parm_bool(-1, "groupmap", "nosync", False)) {
-		flags |= LDB_FLG_NOSYNC;
-	}
-
-	if (!lp_use_mmap()) {
-		flags |= LDB_FLG_NOMMAP;
-	}
-
-	ret = ldb_connect(ldb, db_path, flags, NULL);
-	if (ret != LDB_SUCCESS) {
-		goto failed;
-	}
-
-	/* force the permissions on the ldb to 0600 - this will fix
-	   existing databases as well as new ones */
-	if (chmod(db_path, 0600) != 0) {
-		goto failed;
-	}
-
-	if (!existed) {
-		/* initialise the ldb with an index */
-		struct ldb_ldif *ldif;
-		int i;
-		for (i=0;i<ARRAY_SIZE(init_ldif);i++) {
-			ldif = ldb_ldif_read_string(ldb, &init_ldif[i]);
-			if (ldif == NULL) goto failed;
-			ret = ldb_add(ldb, ldif->msg);
-			talloc_free(ldif);
-			if (ret == -1) goto failed;
-		}
-	}
-
-	/* possibly upgrade */
-	tdb_path = state_path("group_mapping.tdb");
-	if (file_exist(tdb_path) && !mapping_upgrade(tdb_path)) {
-		unlink(state_path("group_mapping.ldb"));
-		goto failed;
-	}
-
-	return True;
-
-failed:
-	DEBUG(0,("Failed to open group mapping ldb '%s' - '%s'\n",
-		 db_path, ldb?ldb_errstring(ldb):strerror(errno)));
-	talloc_free(ldb);
-	ldb = NULL;
-	return False;
-}
-
-
-/*
-  form the DN for a mapping entry from a SID
- */
-static struct ldb_dn *mapping_dn(TALLOC_CTX *mem_ctx, const DOM_SID *sid)
-{
-	fstring string_sid;
-	uint32_t rid;
-	DOM_SID domsid;
-
-	sid_copy(&domsid, sid);
-	if (!sid_split_rid(&domsid, &rid)) {
-		return NULL;
-	}
-      	if (!sid_to_fstring(string_sid, &domsid)) {
-		return NULL;
-	}
-	/* we split by domain and rid so we can do a subtree search
-	   when we only want one domain */
-	return ldb_dn_new_fmt(mem_ctx, ldb, "rid=%u,domain=%s", 
-			      rid, string_sid);
-}
-
-/*
-  add a group mapping entry
- */
-static bool add_mapping_entry(GROUP_MAP *map, int flag)
-{
-	struct ldb_message *msg;	
-	int ret, i;
-	fstring string_sid;
-
-	msg = ldb_msg_new(ldb);
-	if (msg == NULL) {
-		return False;
-	}
-
-	msg->dn = mapping_dn(msg, &map->sid);
-	if (msg->dn == NULL) {
-		goto failed;
-	}
-
-	if (ldb_msg_add_string(msg, "objectClass", "groupMap") != LDB_SUCCESS ||
-	    ldb_msg_add_string(msg, "sid", 
-			       sid_to_fstring(string_sid, &map->sid)) != LDB_SUCCESS ||
-	    ldb_msg_add_fmt(msg, "gidNumber", "%u", (unsigned)map->gid) != LDB_SUCCESS ||
-	    ldb_msg_add_fmt(msg, "sidNameUse", "%u", (unsigned)map->sid_name_use) != LDB_SUCCESS ||
-	    ldb_msg_add_string(msg, "comment", map->comment) != LDB_SUCCESS ||
-	    ldb_msg_add_string(msg, "ntName", map->nt_name) != LDB_SUCCESS) {
-		goto failed;
-	}
-
-	ret = ldb_add(ldb, msg);
-
-	/* if it exists we update it. This is a hangover from the semantics the
-	   tdb backend had */
-	if (ret == LDB_ERR_ENTRY_ALREADY_EXISTS) {
-		for (i=0;i<msg->num_elements;i++) {
-			msg->elements[i].flags = LDB_FLAG_MOD_REPLACE;
-		}
-		ret = ldb_modify(ldb, msg);
-	}
-
-	talloc_free(msg);
-
-	return ret == LDB_SUCCESS;
-
-failed:
-	talloc_free(msg);
-	return False;
-}
-
-/*
-  unpack a ldb message into a GROUP_MAP structure
-*/
-static bool msg_to_group_map(struct ldb_message *msg, GROUP_MAP *map)
-{
-	const char *sidstr;
-
-	map->gid          = ldb_msg_find_attr_as_int(msg, "gidNumber", -1);
-	map->sid_name_use = ldb_msg_find_attr_as_int(msg, "sidNameUse", -1);
-	fstrcpy(map->nt_name, ldb_msg_find_attr_as_string(msg, "ntName", NULL));
-	fstrcpy(map->comment, ldb_msg_find_attr_as_string(msg, "comment", NULL));
-	sidstr = ldb_msg_find_attr_as_string(msg, "sid", NULL);
-
-	if (!string_to_sid(&map->sid, sidstr) ||
-	    map->gid == (gid_t)-1 ||
-	    map->sid_name_use == (enum lsa_SidType)-1) {
-		DEBUG(0,("Unable to unpack group mapping\n"));
-		return False;
-	}
-
-	return True;
-}
-
-/*
- return a group map entry for a given sid
-*/
-static bool get_group_map_from_sid(DOM_SID sid, GROUP_MAP *map)
-{
-	int ret;
-	struct ldb_dn *dn;
-	struct ldb_result *res=NULL;
-	bool result = false;
-
-	dn = mapping_dn(talloc_tos(), &sid);
-	if (dn == NULL) {
-		goto failed;
-	}
-
-	ret = ldb_search(ldb, dn, &res, dn, LDB_SCOPE_BASE, NULL, NULL);
-	if (ret != LDB_SUCCESS || res->count != 1) {
-		goto failed;
-	}
-
-	if (!msg_to_group_map(res->msgs[0], map)) {
-		goto failed;
-	}
-
-	result = true;
- failed:
-	talloc_free(dn);
-	return result;
-}
-
-/*
- return a group map entry for a given gid
-*/
-static bool get_group_map_from_gid(gid_t gid, GROUP_MAP *map)
-{
-	int ret;
-	struct ldb_result *res=NULL;
-	bool result = false;
-
-	ret = ldb_search(ldb, talloc_tos(), &res, NULL, LDB_SCOPE_SUBTREE,
-			 NULL, "(&(gidNumber=%u)(objectClass=groupMap))",
-			 (unsigned)gid);
-	if (ret != LDB_SUCCESS || res->count != 1) {
-		goto failed;
-	}
-
-	if (!msg_to_group_map(res->msgs[0], map)) {
-		goto failed;
-	}
-
-	result = true;
-failed:
-	TALLOC_FREE(res);
-	return result;
-}
-
-/*
-  Return the sid and the type of the unix group.
-*/
-static bool get_group_map_from_ntname(const char *name, GROUP_MAP *map)
-{
-	int ret;
-	struct ldb_result *res=NULL;
-	bool result = false;
-
-	ret = ldb_search(ldb, talloc_tos(), &res, NULL, LDB_SCOPE_SUBTREE,
-			 NULL, "(&(ntName=%s)(objectClass=groupMap))", name);
-	if (ret != LDB_SUCCESS || res->count != 1) {
-		goto failed;
-	}
-
-	if (!msg_to_group_map(res->msgs[0], map)) {
-		goto failed;
-	}
-
-	result = true;
- failed:
-	TALLOC_FREE(res);
-	return result;
-}
-
-/*
- Remove a group mapping entry.
-*/
-static bool group_map_remove(const DOM_SID *sid)
-{
-	struct ldb_dn *dn;
-	int ret;
-	
-	dn = mapping_dn(ldb, sid);
-	if (dn == NULL) {
-		return False;
-	}
-	ret = ldb_delete(ldb, dn);
-	talloc_free(dn);
-
-	return ret == LDB_SUCCESS;
-}
-
-
-/*
-  Enumerate the group mappings for a domain
-*/
-static bool enum_group_mapping(const DOM_SID *domsid, enum lsa_SidType sid_name_use, 
-			       GROUP_MAP **pp_rmap,
-			       size_t *p_num_entries, bool unix_only)
-{
-	int i, ret;
-	fstring name;
-	struct ldb_result *res = NULL;
-	struct ldb_dn *basedn=NULL;
-	TALLOC_CTX *tmp_ctx;
-
-	tmp_ctx = talloc_new(ldb);
-	if (tmp_ctx == NULL) goto failed;
-
-	/* we do a subtree search on the domain */
-	if (domsid != NULL) {
-		sid_to_fstring(name, domsid);
-		basedn = ldb_dn_new_fmt(tmp_ctx, ldb, "domain=%s", name);
-		if (basedn == NULL) goto failed;
-	}
-
-	if (sid_name_use == SID_NAME_UNKNOWN) {
-		ret = ldb_search(ldb, tmp_ctx, &res, basedn, LDB_SCOPE_SUBTREE,
-				 NULL, "(&(objectClass=groupMap))");
-	} else {
-		ret = ldb_search(ldb, tmp_ctx, &res, basedn, LDB_SCOPE_SUBTREE,
-				 NULL, "(&(sidNameUse=%u)(objectClass=groupMap))",
-				 sid_name_use);
-	}
-
-	if (ret != LDB_SUCCESS) goto failed;
-
-	(*pp_rmap) = NULL;
-	*p_num_entries = 0;
-
-	for (i=0;i<res->count;i++) {
-		(*pp_rmap) = SMB_REALLOC_ARRAY((*pp_rmap), GROUP_MAP, 
-					       (*p_num_entries)+1);
-		if (!(*pp_rmap)) goto failed;
-
-		if (!msg_to_group_map(res->msgs[i], &(*pp_rmap)[*p_num_entries])) {
-			goto failed;
-		}
-
-		(*p_num_entries)++;
-	}
-
-	talloc_free(tmp_ctx);
-	return True;
-
-failed:
-	talloc_free(tmp_ctx);
-	return False;	
-}
-
-/* 
-   This operation happens on session setup, so it should better be fast. We
-   store a list of aliases a SID is member of hanging off MEMBEROF/SID. 
-*/
-static NTSTATUS one_alias_membership(const DOM_SID *member,
-				     DOM_SID **sids, size_t *num)
-{
-	const char *attrs[] = {
-		"sid",
-		NULL
-	};
-	DOM_SID alias;
-	int ret, i;
-	struct ldb_result *res=NULL;
-	fstring string_sid;
-	NTSTATUS status;
-
-      	if (!sid_to_fstring(string_sid, member)) {
-		return NT_STATUS_INVALID_PARAMETER;
-	}
-
-	ret = ldb_search(ldb, talloc_tos(), &res, NULL, LDB_SCOPE_SUBTREE,
-			 attrs, "(&(member=%s)(objectClass=groupMap))",
-			 string_sid);
-	if (ret != LDB_SUCCESS) {
-		status = NT_STATUS_INTERNAL_DB_CORRUPTION;
-		goto failed;
-	}
-
-	for (i=0;i<res->count;i++) {
-		struct ldb_message_element *el;
-		el = ldb_msg_find_element(res->msgs[i], "sid");
-		if (el == NULL || el->num_values != 1) {
-			status = NT_STATUS_INTERNAL_DB_CORRUPTION;
-			goto failed;
-		}
-		string_to_sid(&alias, (char *)el->values[0].data);
-		status = add_sid_to_array_unique(NULL, &alias, sids, num);
-		if (!NT_STATUS_IS_OK(status)) {
-			goto failed;
-		}
-	}
-
-	status = NT_STATUS_OK;
- failed:
-	TALLOC_FREE(res);
-	return status;
-}
-
-/*
-  add/remove a member field
-*/
-static NTSTATUS modify_aliasmem(const DOM_SID *alias, const DOM_SID *member,
-				int operation)
-{
-	fstring string_sid;
-	int ret;
-	struct ldb_message msg;
-	struct ldb_message_element el;
-	struct ldb_val val;
-	TALLOC_CTX *tmp_ctx;
-	GROUP_MAP map;
-
-	if (!get_group_map_from_sid(*alias, &map)) {
-		sid_to_fstring(string_sid, alias);
-		return NT_STATUS_NO_SUCH_ALIAS;
-	}
-
-	if ((map.sid_name_use != SID_NAME_ALIAS) &&
-	    (map.sid_name_use != SID_NAME_WKN_GRP)) {
-		DEBUG(0,("sid_name_use=%d\n", map.sid_name_use));
-		return NT_STATUS_NO_SUCH_ALIAS;
-	}
-
-	tmp_ctx = talloc_new(NULL);
-	if (tmp_ctx == NULL) {
-		return NT_STATUS_NO_MEMORY;
-	}
-
-	msg.dn = mapping_dn(tmp_ctx, alias);
-	if (msg.dn == NULL) {
-		return NT_STATUS_NO_MEMORY;
-	}
-	msg.num_elements = 1;
-	msg.elements = &el;
-	el.flags = operation;
-	el.name = talloc_strdup(tmp_ctx, "member");
-	el.num_values = 1;
-	el.values = &val;
-	sid_to_fstring(string_sid, member);
-	val.data = (uint8_t *)string_sid;
-	val.length = strlen(string_sid);
-
-	ret = ldb_modify(ldb, &msg);
-	talloc_free(tmp_ctx);
-
-	if (ret == LDB_ERR_NO_SUCH_OBJECT) {
-		return NT_STATUS_NO_SUCH_ALIAS;
-	}
-
-	if (operation == LDB_FLAG_MOD_ADD &&
-	    ret == LDB_ERR_ATTRIBUTE_OR_VALUE_EXISTS) {
-		return NT_STATUS_MEMBER_IN_ALIAS;
-	}
-
-	return (ret == LDB_SUCCESS ? NT_STATUS_OK : NT_STATUS_ACCESS_DENIED);
-}
-
-static NTSTATUS add_aliasmem(const DOM_SID *alias, const DOM_SID *member)
-{
-	return modify_aliasmem(alias, member, LDB_FLAG_MOD_ADD);
-}
-
-static NTSTATUS del_aliasmem(const DOM_SID *alias, const DOM_SID *member)
-{
-	return modify_aliasmem(alias, member, LDB_FLAG_MOD_DELETE);
-}
-
-
-/*
-  enumerate sids that have the given alias set in member
-*/
-static NTSTATUS enum_aliasmem(const DOM_SID *alias, TALLOC_CTX *mem_ctx,
-			      DOM_SID **sids, size_t *num)
-{
-	const char *attrs[] = {
-		"member",
-		NULL
-	};
-	int ret, i;
-	NTSTATUS status = NT_STATUS_OK;
-	struct ldb_result *res=NULL;
-	struct ldb_dn *dn;
-	struct ldb_message_element *el;
-	
-	*sids = NULL;
-	*num = 0;
-
-	dn = mapping_dn(ldb, alias);
-	if (dn == NULL) {
-		return NT_STATUS_NO_MEMORY;
-	}
-
-	ret = ldb_search(ldb, ldb, &res, dn, LDB_SCOPE_BASE, attrs, NULL);
-	if (ret == LDB_SUCCESS && res->count == 0) {
-		talloc_free(res);
-		talloc_free(dn);
-		return NT_STATUS_OK;
-	}
-	if (ret != LDB_SUCCESS) {
-		talloc_free(dn);
-		return NT_STATUS_INTERNAL_DB_CORRUPTION;
-	}
-
-	talloc_steal(dn, res);
-	el = ldb_msg_find_element(res->msgs[0], "member");
-	if (el == NULL) {
-		talloc_free(dn);
-		return NT_STATUS_OK;
-	}
-	
-	for (i=0;i<el->num_values;i++) {
-		DOM_SID sid;
-		string_to_sid(&sid, (const char *)el->values[i].data);
-		status = add_sid_to_array_unique(mem_ctx, &sid, sids, num);
-		if (!NT_STATUS_IS_OK(status)) {
-			goto done;
-		}
-	}
-
-done:
-	talloc_free(dn);
-	return status;
-}
-
-/*
-  upgrade one group mapping record from the old tdb format
-*/
-static int upgrade_map_record(TDB_CONTEXT *tdb_ctx, TDB_DATA key, 
-			      TDB_DATA data, void *state)
-{
-	int ret;
-	GROUP_MAP map;
-
-	if (strncmp((char *)key.dptr, GROUP_PREFIX, 
-		    MIN(key.dsize, strlen(GROUP_PREFIX))) != 0) {
-		return 0;
-	}
-
-	if (!string_to_sid(&map.sid, strlen(GROUP_PREFIX) + (const char *)key.dptr)) {
-		DEBUG(0,("Bad sid key '%s' during upgrade\n", (const char *)key.dptr));
-		*(int *)state = -1;
-		return -1;
-	}
-
-	ret = tdb_unpack(data.dptr, data.dsize, "ddff",
-			 &map.gid, &map.sid_name_use, &map.nt_name, &map.comment);
-	if (ret == -1) {
-		DEBUG(0,("Failed to unpack group map record during upgrade\n"));
-		*(int *)state = -1;
-		return -1;
-	}
-
-	if ((int)map.gid == -1) {
-		/*
-		 * Ignore old invalid mappings
-		 */
-		return 0;
-	}
-
-	if (!add_mapping_entry(&map, 0)) {
-		DEBUG(0,("Failed to add mapping entry during upgrade\n"));
-		*(int *)state = -1;
-		return -1;
-	}
-
-	return 0;
-}
-
-/*
-  upgrade one alias record from the old tdb format
-*/
-static int upgrade_alias_record(TDB_CONTEXT *tdb_ctx, TDB_DATA key, 
-				TDB_DATA data, void *state)
-{
-	const char *p = (const char *)data.dptr;
-	char *string_sid;
-	DOM_SID member;
-	TALLOC_CTX *frame;
-
-	if (strncmp((char *)key.dptr, MEMBEROF_PREFIX, 
-		    MIN(key.dsize, strlen(MEMBEROF_PREFIX))) != 0) {
-		return 0;
-	}
-
-	if (!string_to_sid(&member, strlen(MEMBEROF_PREFIX) + (const char *)key.dptr)) {
-		DEBUG(0,("Bad alias key %s during upgrade\n",
-			 (const char *)key.dptr));
-		*(int *)state = -1;
-	}
-
-	frame = talloc_stackframe();
-	while (next_token_talloc(frame,&p, &string_sid, " ")) {
-		DOM_SID alias;
-		NTSTATUS status;
-		string_to_sid(&alias, string_sid);
-		status = add_aliasmem(&alias, &member);
-		if (NT_STATUS_EQUAL(status, NT_STATUS_NO_SUCH_ALIAS)) {
-			DEBUG(0,("Ignoring orphaned alias record '%s'\n", 
-				 string_sid));
-		} else if (!NT_STATUS_IS_OK(status)) {
-			DEBUG(0,("Failed to add alias member during upgrade - %s\n",
-				 nt_errstr(status)));
-			*(int *)state = -1;
-			TALLOC_FREE(frame);
-			return -1;
-		}
-	}
-	TALLOC_FREE(frame);
-	return 0;
-}
-
-/*
-  upgrade from a old style tdb
-*/
-static bool mapping_upgrade(const char *tdb_path)
-{
-	static TDB_CONTEXT *tdb;
-	int ret, status=0;
-
-	tdb = tdb_open_log(tdb_path, 0, TDB_DEFAULT, O_RDWR, 0600);
-	if (tdb == NULL) goto failed;
-
-	/* we have to do the map records first, as alias records may
-	   reference them */
-	ret = tdb_traverse(tdb, upgrade_map_record, &status);
-	if (ret == -1 || status == -1) goto failed;
-
-	ret = tdb_traverse(tdb, upgrade_alias_record, &status);
-	if (ret == -1 || status == -1) goto failed;
-
-	if (tdb) {
-		tdb_close(tdb);
-		tdb = NULL;
-	}
-
-	{
-		const char *old_path = tdb_path;
-		char *new_path = state_path("group_mapping.tdb.upgraded");
-
-		if (!new_path) {
-			goto failed;
-		}
-		if (rename(old_path, new_path) != 0) {
-			DEBUG(0,("Failed to rename old group mapping database\n"));
-			goto failed;
-		}
-	}
-	return True;
-
-failed:
-	DEBUG(0,("Failed to upgrade group mapping database\n"));
-	if (tdb) tdb_close(tdb);
-	return False;
-}
-
-
-
-static const struct mapping_backend ldb_backend = {
-	.add_mapping_entry         = add_mapping_entry,
-	.get_group_map_from_sid    = get_group_map_from_sid,
-	.get_group_map_from_gid    = get_group_map_from_gid,
-	.get_group_map_from_ntname = get_group_map_from_ntname,
-	.group_map_remove          = group_map_remove,
-	.enum_group_mapping        = enum_group_mapping,
-	.one_alias_membership      = one_alias_membership,
-	.add_aliasmem              = add_aliasmem,
-	.del_aliasmem              = del_aliasmem,
-	.enum_aliasmem             = enum_aliasmem	
-};
-
-/*
-  initialise the ldb mapping backend
- */
-const struct mapping_backend *groupdb_ldb_init(void)
-{
-	if (!init_group_mapping()) {
-		DEBUG(0,("Failed to initialise ldb mapping backend\n"));
-		return NULL;
-	}
-
-	return &ldb_backend;
-}
diff --git a/source3/groupdb/mapping_tdb.c b/source3/groupdb/mapping_tdb.c
index 8498f0c821..06d35fe7c2 100644
--- a/source3/groupdb/mapping_tdb.c
+++ b/source3/groupdb/mapping_tdb.c
@@ -25,15 +25,22 @@
 
 static struct db_context *db; /* used for driver files */
 
-static bool enum_group_mapping(const DOM_SID *domsid, enum lsa_SidType sid_name_use, GROUP_MAP **pp_rmap,
-			       size_t *p_num_entries, bool unix_only);
+static bool enum_group_mapping(const DOM_SID *domsid,
+			       enum lsa_SidType sid_name_use,
+			       GROUP_MAP **pp_rmap,
+			       size_t *p_num_entries,
+			       bool unix_only);
 static bool group_map_remove(const DOM_SID *sid);
-	
+
+static bool mapping_switch(const char *ldb_path);
+
 /****************************************************************************
  Open the group mapping tdb.
 ****************************************************************************/
 static bool init_group_mapping(void)
 {
+	const char *ldb_path;
+
 	if (db != NULL) {
 		return true;
 	}
@@ -46,13 +53,14 @@ static bool init_group_mapping(void)
 		return false;
 	}
 
-#if 0
-	/*
-	 * This code was designed to handle a group mapping version
-	 * upgrade. mapping_tdb is not active by default anymore, so ignore
-	 * this here.
-	 */
-	{
+	ldb_path = state_path("group_mapping.ldb");
+	if (file_exist(ldb_path) && !mapping_switch(ldb_path)) {
+		unlink(state_path("group_mapping.tdb"));
+		return false;
+
+	} else {
+		/* handle upgrade from old versions of the database */
+#if 0 /* -- Needs conversion to dbwrap -- */
 		const char *vstring = "INFO/version";
 		int32 vers_id;
 		GROUP_MAP *map_table = NULL;
@@ -96,9 +104,8 @@ static bool init_group_mapping(void)
 
 			SAFE_FREE( map_table );
 		}
-	}
 #endif
-
+	}
 	return true;
 }
 
@@ -719,6 +726,254 @@ static NTSTATUS del_aliasmem(const DOM_SID *alias, const DOM_SID *member)
 	return status;
 }
 
+
+/* -- ldb->tdb switching code -------------------------------------------- */
+
+/* change this if the data format ever changes */
+#define LTDB_PACKING_FORMAT 0x26011967
+
+/* old packing formats (not supported for now,
+ * it was never used for group mapping AFAIK) */
+#define LTDB_PACKING_FORMAT_NODN 0x26011966
+
+static unsigned int pull_uint32(uint8_t *p, int ofs)
+{
+	p += ofs;
+	return p[0] | (p[1]<<8) | (p[2]<<16) | (p[3]<<24);
+}
+
+/*
+  unpack a ldb message from a linear buffer in TDB_DATA
+*/
+static int convert_ldb_record(TDB_CONTEXT *ltdb, TDB_DATA key,
+			      TDB_DATA data, void *ptr)
+{
+	TALLOC_CTX *tmp_ctx = talloc_tos();
+	GROUP_MAP map;
+	uint8_t *p;
+	uint32_t format;
+	uint32_t num_el;
+	unsigned int remaining;
+	unsigned int i, j;
+	size_t len;
+	char *name;
+	char *val;
+	char *q;
+	uint32_t num_mem = 0;
+	DOM_SID *members;
+
+	p = (uint8_t *)data.dptr;
+	if (data.dsize < 8) {
+		errno = EIO;
+		goto failed;
+	}
+
+	format = pull_uint32(p, 0);
+	num_el = pull_uint32(p, 4);
+	p += 8;
+
+	remaining = data.dsize - 8;
+
+	switch (format) {
+	case LTDB_PACKING_FORMAT:
+		len = strnlen((char *)p, remaining);
+		if (len == remaining) {
+			errno = EIO;
+			goto failed;
+		}
+
+		if (*p == '@') {
+			/* ignore special LDB attributes */
+			return 0;
+		}
+
+		if (strncmp((char *)p, "rid=", 4)) {
+			/* unknown entry, ignore */
+			DEBUG(3, ("Found unknown entry in group mapping "
+				  "database named [%s]\n", (char *)p));
+			return 0;
+		}
+
+		remaining -= len + 1;
+		p += len + 1;
+		break;
+
+	case LTDB_PACKING_FORMAT_NODN:
+	default:
+		errno = EIO;
+		goto failed;
+	}
+
+	if (num_el == 0) {
+		/* bad entry, ignore */
+		return 0;
+	}
+
+	if (num_el > remaining / 6) {
+		errno = EIO;
+		goto failed;
+	}
+
+	ZERO_STRUCT(map);
+
+	for (i = 0; i < num_el; i++) {
+		uint32_t num_vals;
+
+		if (remaining < 10) {
+			errno = EIO;
+			goto failed;
+		}
+		len = strnlen((char *)p, remaining - 6);
+		if (len == remaining - 6) {
+			errno = EIO;
+			goto failed;
+		}
+		name = talloc_strndup(tmp_ctx, (char *)p, len);
+		if (name == NULL) {
+			errno = ENOMEM;
+			goto failed;
+		}
+		remaining -= len + 1;
+		p += len + 1;
+
+		num_vals = pull_uint32(p, 0);
+		if (StrCaseCmp(name, "member") == 0) {
+			num_mem = num_vals;
+			members = talloc_array(tmp_ctx, DOM_SID, num_mem);
+			if (members == NULL) {
+				errno = ENOMEM;
+				goto failed;
+			}
+		} else if (num_vals != 1) {
+			errno = EIO;
+			goto failed;
+		}
+
+		p += 4;
+		remaining -= 4;
+
+		for (j = 0; j < num_vals; j++) {
+			len = pull_uint32(p, 0);
+			if (len > remaining-5) {
+				errno = EIO;
+				goto failed;
+			}
+
+			val = talloc_strndup(tmp_ctx, (char *)(p + 4), len);
+			if (val == NULL) {
+				errno = ENOMEM;
+				goto failed;
+			}
+
+			remaining -= len+4+1;
+			p += len+4+1;
+
+			/* we ignore unknown or uninteresting attributes
+			 * (objectclass, etc.) */
+			if (StrCaseCmp(name, "gidNumber") == 0) {
+				map.gid = strtoul(val, &q, 10);
+				if (*q) {
+					errno = EIO;
+					goto failed;
+				}
+			} else if (StrCaseCmp(name, "sid") == 0) {
+				if (!string_to_sid(&map.sid, val)) {
+					errno = EIO;
+					goto failed;
+				}
+			} else if (StrCaseCmp(name, "sidNameUse") == 0) {
+				map.sid_name_use = strtoul(val, &q, 10);
+				if (*q) {
+					errno = EIO;
+					goto failed;
+				}
+			} else if (StrCaseCmp(name, "ntname") == 0) {
+				strlcpy(map.nt_name, val,
+					sizeof(map.nt_name) -1);
+			} else if (StrCaseCmp(name, "comment") == 0) {
+				strlcpy(map.comment, val,
+					sizeof(map.comment) -1);
+			} else if (StrCaseCmp(name, "member") == 0) {
+				if (!string_to_sid(&members[j], val)) {
+					errno = EIO;
+					goto failed;
+				}
+			}
+
+			TALLOC_FREE(val);
+		}
+
+		TALLOC_FREE(name);
+	}
+
+	if (!add_mapping_entry(&map, 0)) {
+		errno = EIO;
+		goto failed;
+	}
+
+	if (num_mem) {
+		for (j = 0; j < num_mem; j++) {
+			NTSTATUS status;
+			status = add_aliasmem(&map.sid, &members[j]);
+			if (!NT_STATUS_IS_OK(status)) {
+				errno = EIO;
+				goto failed;
+			}
+		}
+	}
+
+	if (remaining != 0) {
+		DEBUG(0, ("Errror: %d bytes unread in ltdb_unpack_data\n",
+			  remaining));
+	}
+
+	return 0;
+
+failed:
+	return -1;
+}
+
+static bool mapping_switch(const char *ldb_path)
+{
+	static TALLOC_CTX *ltdb;
+	TALLOC_CTX *frame;
+	char *new_path;
+	int ret;
+
+	frame = talloc_stackframe();
+
+	ltdb = tdb_open_log(ldb_path, 0, TDB_DEFAULT, O_RDONLY, 0600);
+	if (ltdb == NULL) goto failed;
+
+	/* ldb is just a very fancy tdb, read out raw data and perform
+	 * conversion */
+	ret = tdb_traverse(ltdb, convert_ldb_record, NULL);
+	if (ret == -1) goto failed;
+
+	if (ltdb) {
+		tdb_close(ltdb);
+		ltdb = NULL;
+	}
+
+	/* now rename the old db out of the way */
+	new_path = state_path("group_mapping.ldb.replaced");
+	if (!new_path) {
+		goto failed;
+	}
+	if (rename(ldb_path, new_path) != 0) {
+		DEBUG(0,("Failed to rename old group mapping database\n"));
+		goto failed;
+	}
+	TALLOC_FREE(frame);
+	return True;
+
+failed:
+	DEBUG(0,("Failed to swith to tdb group mapping database\n"));
+	if (ltdb) tdb_close(ltdb);
+	TALLOC_FREE(frame);
+	return False;
+}
+
 static const struct mapping_backend tdb_backend = {
 	.add_mapping_entry         = add_mapping_entry,
 	.get_group_map_from_sid    = get_group_map_from_sid,