Convert mapping_tdb.c to dbwrap

I know, this is not used anymore, but until ldb knows about ctdb which is
blocked by the lack of transactions in ctdb, a tiny patch reactivating
mapping_tdb.c might be needed for cluster setups.
(This used to be commit 8e0fa453a3d0a2c997a935b6940796612c972708)

2 files changed, 281 insertions, 292 deletions

diff --git a/source3/groupdb/mapping.h b/source3/groupdb/mapping.h
index 4af38314f8..c37ae84b87 100644
--- a/source3/groupdb/mapping.h
+++ b/source3/groupdb/mapping.h
@@ -2,6 +2,7 @@
 #define DATABASE_VERSION_V2 2 /* le format. */
 
 #define GROUP_PREFIX "UNIXGROUP/"
+#define GROUP_PREFIX_LEN 10
 
 /* Alias memberships are stored reverse, as memberships. The performance
  * critical operation is to determine the aliases a SID is member of, not
@@ -9,6 +10,7 @@
  * hanging of the member as key.
  */
 #define MEMBEROF_PREFIX "MEMBEROF/"
+#define MEMBEROF_PREFIX_LEN 9
 
 /*
   groupdb mapping backend abstraction
diff --git a/source3/groupdb/mapping_tdb.c b/source3/groupdb/mapping_tdb.c
index 31937840d9..c9c8cdcaeb 100644
--- a/source3/groupdb/mapping_tdb.c
+++ b/source3/groupdb/mapping_tdb.c
@@ -23,7 +23,7 @@
 #include "includes.h"
 #include "groupdb/mapping.h"
 
-static TDB_CONTEXT *tdb; /* used for driver files */
+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);
@@ -34,97 +34,119 @@ static bool group_map_remove(const DOM_SID *sid);
 ****************************************************************************/
 static bool init_group_mapping(void)
 {
-	const char *vstring = "INFO/version";
-	int32 vers_id;
-	GROUP_MAP *map_table = NULL;
-	size_t num_entries = 0;
-	
-	if (tdb)
-		return True;
-		
-	tdb = tdb_open_log(state_path("group_mapping.tdb"), 0, TDB_DEFAULT, O_RDWR|O_CREAT, 0600);
-	if (!tdb) {
-		DEBUG(0,("Failed to open group mapping database\n"));
-		return False;
+	if (db != NULL) {
+		return true;
 	}
 
-	/* handle a Samba upgrade */
-	tdb_lock_bystring(tdb, vstring);
-
-	/* Cope with byte-reversed older versions of the db. */
-	vers_id = tdb_fetch_int32(tdb, vstring);
-	if ((vers_id == DATABASE_VERSION_V1) || (IREV(vers_id) == DATABASE_VERSION_V1)) {
-		/* Written on a bigendian machine with old fetch_int code. Save as le. */
-		tdb_store_int32(tdb, vstring, DATABASE_VERSION_V2);
-		vers_id = DATABASE_VERSION_V2;
+	db = db_open(NULL, state_path("group_mapping.tdb"), 0, TDB_DEFAULT,
+		     O_RDWR|O_CREAT, 0600);
+	if (db == NULL) {
+		DEBUG(0, ("Failed to open group mapping database: %s\n",
+			  strerror(errno)));
+		return false;
 	}
 
-	/* if its an unknown version we remove everthing in the db */
-	
-	if (vers_id != DATABASE_VERSION_V2) {
-		tdb_traverse(tdb, tdb_traverse_delete_fn, NULL);
-		tdb_store_int32(tdb, vstring, DATABASE_VERSION_V2);
-	}
+#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.
+	 */
+	{
+		const char *vstring = "INFO/version";
+		int32 vers_id;
+		GROUP_MAP *map_table = NULL;
+		size_t num_entries = 0;
+
+		/* handle a Samba upgrade */
+		tdb_lock_bystring(tdb, vstring);
+
+		/* Cope with byte-reversed older versions of the db. */
+		vers_id = tdb_fetch_int32(tdb, vstring);
+		if ((vers_id == DATABASE_VERSION_V1)
+		    || (IREV(vers_id) == DATABASE_VERSION_V1)) {
+			/*
+			 * Written on a bigendian machine with old fetch_int
+			 * code. Save as le.
+			 */
+			tdb_store_int32(tdb, vstring, DATABASE_VERSION_V2);
+			vers_id = DATABASE_VERSION_V2;
+		}
 
-	tdb_unlock_bystring(tdb, vstring);
+		/* if its an unknown version we remove everthing in the db */
 
-	/* cleanup any map entries with a gid == -1 */
-	
-	if ( enum_group_mapping( NULL, SID_NAME_UNKNOWN, &map_table, &num_entries, False ) ) {
-		int i;
-		
-		for ( i=0; i<num_entries; i++ ) {
-			if ( map_table[i].gid == -1 ) {
-				group_map_remove( &map_table[i].sid );
+		if (vers_id != DATABASE_VERSION_V2) {
+			tdb_traverse(tdb, tdb_traverse_delete_fn, NULL);
+			tdb_store_int32(tdb, vstring, DATABASE_VERSION_V2);
+		}
+
+		tdb_unlock_bystring(tdb, vstring);
+
+		/* cleanup any map entries with a gid == -1 */
+
+		if ( enum_group_mapping( NULL, SID_NAME_UNKNOWN, &map_table,
+					 &num_entries, False ) ) {
+			int i;
+
+			for ( i=0; i<num_entries; i++ ) {
+				if ( map_table[i].gid == -1 ) {
+					group_map_remove( &map_table[i].sid );
+				}
 			}
+
+			SAFE_FREE( map_table );
 		}
-		
-		SAFE_FREE( map_table );
+	}
+#endif
+
+	return true;
+}
+
+static char *group_mapping_key(TALLOC_CTX *mem_ctx, const DOM_SID *sid)
+{
+	char *sidstr, *result;
+
+	sidstr = sid_string_talloc(talloc_tos(), sid);
+	if (sidstr == NULL) {
+		return NULL;
 	}
 
+	result = talloc_asprintf(mem_ctx, "GROUP_PREFIX%s", sidstr);
 
-	return True;
+	TALLOC_FREE(sidstr);
+	return result;
 }
 
 /****************************************************************************
 ****************************************************************************/
 static bool add_mapping_entry(GROUP_MAP *map, int flag)
 {
-	TDB_DATA dbuf;
-	char *key, *buf, *sid_string;
+	char *key, *buf;
 	int len;
-	bool ret;
+	NTSTATUS status;
 
-	sid_string = sid_string_talloc(talloc_tos(), &map->sid);
-	if (sid_string == NULL) {
+	key = group_mapping_key(talloc_tos(), &map->sid);
+	if (key == NULL) {
 		return NULL;
 	}
 
 	len = tdb_pack(NULL, sizeof(buf), "ddff",
 		map->gid, map->sid_name_use, map->nt_name, map->comment);
-	if (len) {
-		buf = TALLOC_ARRAY(sid_string, char, len);
-		if (!buf) {
-			TALLOC_FREE(sid_string);
-			return false;
-		}
-		len = tdb_pack((uint8 *)buf, len, "ddff", map->gid,
-				map->sid_name_use, map->nt_name, map->comment);
-	}
 
-	key = talloc_asprintf(sid_string, "%s%s", GROUP_PREFIX, sid_string);
-	if (key == NULL) {
-		TALLOC_FREE(sid_string);
+	buf = TALLOC_ARRAY(key, char, len);
+	if (!buf) {
+		TALLOC_FREE(key);
 		return false;
 	}
+	len = tdb_pack((uint8 *)buf, len, "ddff", map->gid,
+		       map->sid_name_use, map->nt_name, map->comment);
 
-	dbuf.dsize = len;
-	dbuf.dptr = (uint8 *)buf;
+	status = dbwrap_store_bystring(
+		db, key, make_tdb_data((uint8_t *)buf, len), flag);
 
-	ret = (tdb_store_bystring(tdb, key, dbuf, flag) == 0);
+	TALLOC_FREE(key);
 
-	TALLOC_FREE(sid_string);
-	return ret;
+	return NT_STATUS_IS_OK(status);
 }
 
 
@@ -135,129 +157,121 @@ static bool add_mapping_entry(GROUP_MAP *map, int flag)
 static bool get_group_map_from_sid(DOM_SID sid, GROUP_MAP *map)
 {
 	TDB_DATA dbuf;
-	char *key = NULL;
-	fstring string_sid;
+	char *key;
 	int ret = 0;
 
 	/* the key is the SID, retrieving is direct */
 
-	sid_to_fstring(string_sid, &sid);
-	if (asprintf(&key, "%s%s", GROUP_PREFIX, string_sid) < 0) {
+	key = group_mapping_key(talloc_tos(), &map->sid);
+	if (key == NULL) {
 		return false;
 	}
 
-	dbuf = tdb_fetch_bystring(tdb, key);
-	if (!dbuf.dptr) {
-		SAFE_FREE(key);
+	dbuf = dbwrap_fetch_bystring(db, key, key);
+	if (dbuf.dptr == NULL) {
+		TALLOC_FREE(key);
 		return false;
 	}
 
-	SAFE_FREE(key);
-
 	ret = tdb_unpack(dbuf.dptr, dbuf.dsize, "ddff",
 			&map->gid, &map->sid_name_use,
 			&map->nt_name, &map->comment);
 
-	SAFE_FREE(dbuf.dptr);
+	TALLOC_FREE(key);
 
 	if ( ret == -1 ) {
 		DEBUG(3,("get_group_map_from_sid: tdb_unpack failure\n"));
-		return False;
+		return false;
 	}
 
 	sid_copy(&map->sid, &sid);
 
-	return True;
+	return true;
 }
 
-/****************************************************************************
- Return the sid and the type of the unix group.
-****************************************************************************/
-
-static bool get_group_map_from_gid(gid_t gid, GROUP_MAP *map)
+static bool dbrec2map(const struct db_record *rec, GROUP_MAP *map)
 {
-	TDB_DATA kbuf, dbuf, newkey;
-	fstring string_sid;
-	int ret;
-
-	/* we need to enumerate the TDB to find the GID */
-
-	for (kbuf = tdb_firstkey(tdb);
-	     kbuf.dptr;
-	     newkey = tdb_nextkey(tdb, kbuf), safe_free(kbuf.dptr), kbuf=newkey) {
-
-		if (strncmp((const char *)kbuf.dptr, GROUP_PREFIX, strlen(GROUP_PREFIX)) != 0) continue;
+	if ((rec->key.dsize < strlen(GROUP_PREFIX))
+	    || (strncmp((char *)rec->key.dptr, GROUP_PREFIX,
+			GROUP_PREFIX_LEN) != 0)) {
+		return False;
+	}
 
-		dbuf = tdb_fetch(tdb, kbuf);
-		if (!dbuf.dptr)
-			continue;
+	if (!string_to_sid(&map->sid, (const char *)rec->key.dptr
+			   + GROUP_PREFIX_LEN)) {
+		return False;
+	}
 
-		fstrcpy(string_sid, (const char *)kbuf.dptr+strlen(GROUP_PREFIX));
+	return tdb_unpack(rec->value.dptr, rec->value.dsize, "ddff",
+			  &map->gid, &map->sid_name_use, &map->nt_name,
+			  &map->comment) != -1;
+}
 
-		string_to_sid(&map->sid, string_sid);
+struct find_map_state {
+	bool found;
+	const char *name;	/* If != NULL, look for name */
+	gid_t gid;		/* valid iff name == NULL */
+	GROUP_MAP *map;
+};
 
-		ret = tdb_unpack(dbuf.dptr, dbuf.dsize, "ddff",
-				 &map->gid, &map->sid_name_use, &map->nt_name, &map->comment);
+static int find_map(struct db_record *rec, void *private_data)
+{
+	struct find_map_state *state = (struct find_map_state *)private_data;
 
-		SAFE_FREE(dbuf.dptr);
+	if (!dbrec2map(rec, state->map)) {
+		DEBUG(10, ("failed to unpack map\n"));
+		return 0;
+	}
 
-		if ( ret == -1 ) {
-			DEBUG(3,("get_group_map_from_gid: tdb_unpack failure\n"));
-			return False;
+	if (state->name != NULL) {
+		if (strequal(state->name, state->map->nt_name)) {
+			state->found = true;
+			return 1;
 		}
-
-		if (gid==map->gid) {
-			SAFE_FREE(kbuf.dptr);
-			return True;
+	}
+	else {
+		if (state->map->gid == state->gid) {
+			state->found = true;
+			return 1;
 		}
 	}
 
-	return False;
+	return 0;
 }
 
 /****************************************************************************
  Return the sid and the type of the unix group.
 ****************************************************************************/
 
-static bool get_group_map_from_ntname(const char *name, GROUP_MAP *map)
+static bool get_group_map_from_gid(gid_t gid, GROUP_MAP *map)
 {
-	TDB_DATA kbuf, dbuf, newkey;
-	fstring string_sid;
-	int ret;
-
-	/* we need to enumerate the TDB to find the name */
-
-	for (kbuf = tdb_firstkey(tdb);
-	     kbuf.dptr;
-	     newkey = tdb_nextkey(tdb, kbuf), safe_free(kbuf.dptr), kbuf=newkey) {
-
-		if (strncmp((const char *)kbuf.dptr, GROUP_PREFIX, strlen(GROUP_PREFIX)) != 0) continue;
+	struct find_map_state state;
 
-		dbuf = tdb_fetch(tdb, kbuf);
-		if (!dbuf.dptr)
-			continue;
+	state.found = false;
+	state.name = NULL;	/* Indicate we're looking for gid */
+	state.gid = gid;
+	state.map = map;
 
-		fstrcpy(string_sid, (const char *)kbuf.dptr+strlen(GROUP_PREFIX));
+	db->traverse_read(db, find_map, (void *)&state);
 
-		string_to_sid(&map->sid, string_sid);
+	return state.found;
+}
 
-		ret = tdb_unpack(dbuf.dptr, dbuf.dsize, "ddff",
-				 &map->gid, &map->sid_name_use, &map->nt_name, &map->comment);
+/****************************************************************************
+ Return the sid and the type of the unix group.
+****************************************************************************/
 
-		SAFE_FREE(dbuf.dptr);
+static bool get_group_map_from_ntname(const char *name, GROUP_MAP *map)
+{
+	struct find_map_state state;
 
-		if ( ret == -1 ) {
-			DEBUG(3,("get_group_map_from_ntname: tdb_unpack failure\n"));
-			return False;
-		}
+	state.found = false;
+	state.name = name;
+	state.map = map;
 
-		if ( strequal(name, map->nt_name) ) {
-			SAFE_FREE(kbuf.dptr);
-			return True;
-		}
-	}
+	db->traverse_read(db, find_map, (void *)&state);
 
-	return False;
+	return state.found;
 }
 
 /****************************************************************************
@@ -266,123 +280,97 @@ static bool get_group_map_from_ntname(const char *name, GROUP_MAP *map)
 
 static bool group_map_remove(const DOM_SID *sid)
 {
-	TDB_DATA dbuf;
-	char *key = NULL;
-	fstring string_sid;
-	bool ret;
-
-	/* the key is the SID, retrieving is direct */
-
-	sid_to_fstring(string_sid, sid);
-	if (asprintf(&key, "%s%s", GROUP_PREFIX, string_sid) < 0) {
-		return false;
-	}
+	char *key;
+	bool result;
 
-	dbuf = tdb_fetch_bystring(tdb, key);
-	if (!dbuf.dptr) {
-		SAFE_FREE(key);
+	key = group_mapping_key(talloc_tos(), sid);
+	if (key == NULL) {
 		return false;
 	}
 
-	SAFE_FREE(dbuf.dptr);
+	result = NT_STATUS_IS_OK(dbwrap_delete_bystring(db, key));
 
-	ret = (tdb_delete_bystring(tdb, key) == TDB_SUCCESS);
-	SAFE_FREE(key);
-	return ret;
+	TALLOC_FREE(key);
+	return result;
 }
 
 /****************************************************************************
  Enumerate the group mapping.
 ****************************************************************************/
 
-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)
-{
-	TDB_DATA kbuf, dbuf, newkey;
-	fstring string_sid;
-	GROUP_MAP map;
-	GROUP_MAP *mapt;
-	int ret;
-	size_t entries=0;
-	DOM_SID grpsid;
-	uint32 rid;
-
-	*p_num_entries=0;
-	*pp_rmap=NULL;
-
-	for (kbuf = tdb_firstkey(tdb); 
-	     kbuf.dptr; 
-	     newkey = tdb_nextkey(tdb, kbuf), safe_free(kbuf.dptr), kbuf=newkey) {
+struct enum_map_state {
+	const DOM_SID *domsid;
+	enum lsa_SidType sid_name_use;
+	bool unix_only;
 
-		if (strncmp((const char *)kbuf.dptr, GROUP_PREFIX, strlen(GROUP_PREFIX)) != 0)
-			continue;
-
-		dbuf = tdb_fetch(tdb, kbuf);
-		if (!dbuf.dptr)
-			continue;
-
-		fstrcpy(string_sid, (const char *)kbuf.dptr+strlen(GROUP_PREFIX));
-				
-		ret = tdb_unpack(dbuf.dptr, dbuf.dsize, "ddff",
-				 &map.gid, &map.sid_name_use, &map.nt_name, &map.comment);
-
-		SAFE_FREE(dbuf.dptr);
-
-		if ( ret == -1 ) {
-			DEBUG(3,("enum_group_mapping: tdb_unpack failure\n"));
-			continue;
-		}
-	
-		/* list only the type or everything if UNKNOWN */
-		if (sid_name_use!=SID_NAME_UNKNOWN  && sid_name_use!=map.sid_name_use) {
-			DEBUG(11,("enum_group_mapping: group %s is not of the requested type\n", map.nt_name));
-			continue;
-		}
-
-		if (unix_only==ENUM_ONLY_MAPPED && map.gid==-1) {
-			DEBUG(11,("enum_group_mapping: group %s is non mapped\n", map.nt_name));
-			continue;
-		}
+	size_t num_maps;
+	GROUP_MAP *maps;
+};
 
-		string_to_sid(&grpsid, string_sid);
-		sid_copy( &map.sid, &grpsid );
-		
-		sid_split_rid( &grpsid, &rid );
+static int collect_map(struct db_record *rec, void *private_data)
+{
+	struct enum_map_state *state = (struct enum_map_state *)private_data;
+	GROUP_MAP map;
+	GROUP_MAP *tmp;
 
-		/* Only check the domain if we were given one */
+	if (!dbrec2map(rec, &map)) {
+		return 0;
+	}
+	/* list only the type or everything if UNKNOWN */
+	if (state->sid_name_use != SID_NAME_UNKNOWN
+	    && state->sid_name_use != map.sid_name_use) {
+		DEBUG(11,("enum_group_mapping: group %s is not of the "
+			  "requested type\n", map.nt_name));
+		return 0;
+	}
 
-		if ( domsid && !sid_equal( domsid, &grpsid ) ) {
-			DEBUG(11,("enum_group_mapping: group %s is not in "
-				  "domain %s\n", string_sid,
-				  sid_string_dbg(domsid)));
-			continue;
-		}
+	if ((state->unix_only == ENUM_ONLY_MAPPED) && (map.gid == -1)) {
+		DEBUG(11,("enum_group_mapping: group %s is non mapped\n",
+			  map.nt_name));
+		return 0;
+	}
 
-		DEBUG(11,("enum_group_mapping: returning group %s of "
-			  "type %s\n", map.nt_name,
-			  sid_type_lookup(map.sid_name_use)));
+	if ((state->domsid != NULL) &&
+	    (sid_compare_domain(state->domsid, &map.sid) != 0)) {
+		DEBUG(11,("enum_group_mapping: group %s is not in domain\n",
+			  sid_string_dbg(&map.sid)));
+		return 0;
+	}
 
-		(*pp_rmap) = SMB_REALLOC_ARRAY((*pp_rmap), GROUP_MAP, entries+1);
-		if (!(*pp_rmap)) {
-			DEBUG(0,("enum_group_mapping: Unable to enlarge group map!\n"));
-			return False;
-		}
+	if (!(tmp = SMB_REALLOC_ARRAY(state->maps, GROUP_MAP,
+				      state->num_maps+1))) {
+		DEBUG(0,("enum_group_mapping: Unable to enlarge group "
+			 "map!\n"));
+		return 1;
+	}
 
-		mapt = (*pp_rmap);
+	state->maps = tmp;
+	state->maps[state->num_maps] = map;
+	state->num_maps++;
+	return 0;
+}
 
-		mapt[entries].gid = map.gid;
-		sid_copy( &mapt[entries].sid, &map.sid);
-		mapt[entries].sid_name_use = map.sid_name_use;
-		fstrcpy(mapt[entries].nt_name, map.nt_name);
-		fstrcpy(mapt[entries].comment, map.comment);
+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)
+{
+	struct enum_map_state state;
 
-		entries++;
+	state.domsid = domsid;
+	state.sid_name_use = sid_name_use;
+	state.unix_only = unix_only;
+	state.num_maps = 0;
+	state.maps = NULL;
 
+	if (db->traverse_read(db, collect_map, (void *)&state) != 0) {
+		return false;
 	}
 
-	*p_num_entries=entries;
+	*pp_rmap = state.maps;
+	*p_num_entries = state.num_maps;
 
-	return True;
+	return true;
 }
 
 /* This operation happens on session setup, so it should better be fast. We
@@ -397,19 +385,19 @@ static NTSTATUS one_alias_membership(const DOM_SID *member,
 	TDB_DATA dbuf;
 	const char *p;
 	NTSTATUS status = NT_STATUS_OK;
-	TALLOC_CTX *frame;
+	TALLOC_CTX *frame = talloc_stackframe();
 
 	slprintf(key, sizeof(key), "%s%s", MEMBEROF_PREFIX,
 		 sid_to_fstring(tmp, member));
 
-	dbuf = tdb_fetch_bystring(tdb, key);
-
+	dbuf = dbwrap_fetch_bystring(db, frame, key);
 	if (dbuf.dptr == NULL) {
+		TALLOC_FREE(frame);
 		return NT_STATUS_OK;
 	}
 
 	p = (const char *)dbuf.dptr;
-	frame = talloc_stackframe();
+
 	while (next_token_talloc(frame, &p, &string_sid, " ")) {
 		DOM_SID alias;
 
@@ -424,7 +412,6 @@ static NTSTATUS one_alias_membership(const DOM_SID *member,
 
 done:
 	TALLOC_FREE(frame);
-	SAFE_FREE(dbuf.dptr);
 	return status;
 }
 
@@ -468,11 +455,11 @@ static bool is_aliasmem(const DOM_SID *alias, const DOM_SID *member)
 static NTSTATUS add_aliasmem(const DOM_SID *alias, const DOM_SID *member)
 {
 	GROUP_MAP map;
-	TDB_DATA dbuf;
-	char *key = NULL;
+	char *key;
 	fstring string_sid;
 	char *new_memberstring;
-	int result;
+	struct db_record *rec;
+	NTSTATUS status;
 
 	if (!get_group_map_from_sid(*alias, &map))
 		return NT_STATUS_NO_SUCH_ALIAS;
@@ -485,58 +472,67 @@ static NTSTATUS add_aliasmem(const DOM_SID *alias, const DOM_SID *member)
 		return NT_STATUS_MEMBER_IN_ALIAS;
 
 	sid_to_fstring(string_sid, member);
-	if (asprintf(&key, "%s%s", MEMBEROF_PREFIX, string_sid) < 0) {
+
+	key = talloc_asprintf(talloc_tos(), "%s%s", MEMBEROF_PREFIX,
+			      string_sid);
+	if (key == NULL) {
 		return NT_STATUS_NO_MEMORY;
 	}
 
-	dbuf = tdb_fetch_bystring(tdb, key);
+	rec = db->fetch_locked(db, key, string_term_tdb_data(key));
+
+	if (rec == NULL) {
+		DEBUG(10, ("fetch_lock failed\n"));
+		TALLOC_FREE(key);
+		return NT_STATUS_INTERNAL_DB_CORRUPTION;
+	}
 
 	sid_to_fstring(string_sid, alias);
 
-	if (dbuf.dptr != NULL) {
-		asprintf(&new_memberstring, "%s %s", (char *)(dbuf.dptr),
-			 string_sid);
+	if (rec->value.dptr != NULL) {
+		new_memberstring = talloc_asprintf(
+			key, "%s %s", (char *)(rec->value.dptr), string_sid);
 	} else {
-		new_memberstring = SMB_STRDUP(string_sid);
+		new_memberstring = talloc_strdup(key, string_sid);
 	}
 
 	if (new_memberstring == NULL) {
-		SAFE_FREE(key);
+		TALLOC_FREE(key);
 		return NT_STATUS_NO_MEMORY;
 	}
 
-	SAFE_FREE(dbuf.dptr);
-	dbuf = string_term_tdb_data(new_memberstring);
+	status = rec->store(rec, string_term_tdb_data(new_memberstring), 0);
 
-	result = tdb_store_bystring(tdb, key, dbuf, 0);
+	TALLOC_FREE(key);
 
-	SAFE_FREE(new_memberstring);
-	SAFE_FREE(key);
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(10, ("Could not store record: %s\n", nt_errstr(status)));
+	}
 
-	return (result == 0 ? NT_STATUS_OK : NT_STATUS_ACCESS_DENIED);
+	return status;
 }
 
-struct aliasmem_closure {
+struct aliasmem_state {
 	const DOM_SID *alias;
 	DOM_SID **sids;
 	size_t *num;
 };
 
-static int collect_aliasmem(TDB_CONTEXT *tdb_ctx, TDB_DATA key, TDB_DATA data,
-			    void *state)
+static int collect_aliasmem(struct db_record *rec, void *priv)
 {
-	struct aliasmem_closure *closure = (struct aliasmem_closure *)state;
+	struct aliasmem_state *state = (struct aliasmem_state *)priv;
 	const char *p;
 	char *alias_string;
 	TALLOC_CTX *frame;
 
-	if (strncmp((const char *)key.dptr, MEMBEROF_PREFIX,
-		    strlen(MEMBEROF_PREFIX)) != 0)
+	if (strncmp((const char *)rec->key.dptr, MEMBEROF_PREFIX,
+		    MEMBEROF_PREFIX_LEN) != 0)
 		return 0;
 
-	p = (const char *)data.dptr;
+	p = (const char *)rec->value.dptr;
 
 	frame = talloc_stackframe();
+
 	while (next_token_talloc(frame, &p, &alias_string, " ")) {
 		DOM_SID alias, member;
 		const char *member_string;
@@ -544,14 +540,14 @@ static int collect_aliasmem(TDB_CONTEXT *tdb_ctx, TDB_DATA key, TDB_DATA data,
 		if (!string_to_sid(&alias, alias_string))
 			continue;
 
-		if (sid_compare(closure->alias, &alias) != 0)
+		if (sid_compare(state->alias, &alias) != 0)
 			continue;
 
 		/* Ok, we found the alias we're looking for in the membership
 		 * list currently scanned. The key represents the alias
 		 * member. Add that. */
 
-		member_string = strchr((const char *)key.dptr, '/');
+		member_string = strchr((const char *)rec->key.dptr, '/');
 
 		/* Above we tested for MEMBEROF_PREFIX which includes the
 		 * slash. */
@@ -563,8 +559,8 @@ static int collect_aliasmem(TDB_CONTEXT *tdb_ctx, TDB_DATA key, TDB_DATA data,
 			continue;
 
 		if (!NT_STATUS_IS_OK(add_sid_to_array(NULL, &member,
-						      closure->sids,
-						      closure->num)))
+						      state->sids,
+						      state->num)))
 		{
 			/* talloc fail. */
 			break;
@@ -578,7 +574,7 @@ static int collect_aliasmem(TDB_CONTEXT *tdb_ctx, TDB_DATA key, TDB_DATA data,
 static NTSTATUS enum_aliasmem(const DOM_SID *alias, DOM_SID **sids, size_t *num)
 {
 	GROUP_MAP map;
-	struct aliasmem_closure closure;
+	struct aliasmem_state state;
 
 	if (!get_group_map_from_sid(*alias, &map))
 		return NT_STATUS_NO_SUCH_ALIAS;
@@ -590,29 +586,28 @@ static NTSTATUS enum_aliasmem(const DOM_SID *alias, DOM_SID **sids, size_t *num)
 	*sids = NULL;
 	*num = 0;
 
-	closure.alias = alias;
-	closure.sids = sids;
-	closure.num = num;
+	state.alias = alias;
+	state.sids = sids;
+	state.num = num;
 
-	tdb_traverse(tdb, collect_aliasmem, &closure);
+	db->traverse_read(db, collect_aliasmem, &state);
 	return NT_STATUS_OK;
 }
 
 static NTSTATUS del_aliasmem(const DOM_SID *alias, const DOM_SID *member)
 {
-	NTSTATUS result;
+	NTSTATUS status;
 	DOM_SID *sids;
 	size_t i, num;
 	bool found = False;
 	char *member_string;
-	TDB_DATA dbuf;
-	char *key = NULL;
+	char *key;
 	fstring sid_string;
 
-	result = alias_memberships(member, 1, &sids, &num);
+	status = alias_memberships(member, 1, &sids, &num);
 
-	if (!NT_STATUS_IS_OK(result))
-		return result;
+	if (!NT_STATUS_IS_OK(status))
+		return status;
 
 	for (i=0; i<num; i++) {
 		if (sid_compare(&sids[i], alias) == 0) {
@@ -632,54 +627,46 @@ static NTSTATUS del_aliasmem(const DOM_SID *alias, const DOM_SID *member)
 	num -= 1;
 
 	sid_to_fstring(sid_string, member);
-	if (asprintf(&key, "%s%s", MEMBEROF_PREFIX, sid_string) < 0) {
+
+	key = talloc_asprintf(sids, "%s%s", MEMBEROF_PREFIX, sid_string);
+	if (key == NULL) {
 		TALLOC_FREE(sids);
 		return NT_STATUS_NO_MEMORY;
 	}
 
 	if (num == 0) {
-		NTSTATUS ret = (tdb_delete_bystring(tdb, key) == 0 ?
-			NT_STATUS_OK : NT_STATUS_UNSUCCESSFUL);
+		status = dbwrap_delete_bystring(db, key);
 		TALLOC_FREE(sids);
-		SAFE_FREE(key);
-		return ret;
+		return status;
 	}
 
-	member_string = SMB_STRDUP("");
-
+	member_string = talloc_strdup(sids, "");
 	if (member_string == NULL) {
 		TALLOC_FREE(sids);
-		SAFE_FREE(key);
 		return NT_STATUS_NO_MEMORY;
 	}
 
 	for (i=0; i<num; i++) {
-		char *s = member_string;
 
 		sid_to_fstring(sid_string, &sids[i]);
-		asprintf(&member_string, "%s %s", s, sid_string);
 
-		SAFE_FREE(s);
+		member_string = talloc_asprintf_append_buffer(
+			member_string, " %s", sid_string);
+
 		if (member_string == NULL) {
 			TALLOC_FREE(sids);
-			SAFE_FREE(key);
 			return NT_STATUS_NO_MEMORY;
 		}
 	}
 
-	dbuf = string_term_tdb_data(member_string);
-
-	result = tdb_store_bystring(tdb, key, dbuf, 0) == 0 ?
-		NT_STATUS_OK : NT_STATUS_ACCESS_DENIED;
+	status = dbwrap_store_bystring(
+		db, key, string_term_tdb_data(member_string), 0);
 
 	TALLOC_FREE(sids);
-	SAFE_FREE(member_string);
-	SAFE_FREE(key);
 
-	return result;
+	return status;
 }
 
-
 static const struct mapping_backend tdb_backend = {
 	.add_mapping_entry         = add_mapping_entry,
 	.get_group_map_from_sid    = get_group_map_from_sid,