r17525: This is a merge from the Google Summer of Code 2006 project by Martin Kühl

<mkhl@samba.org>.

Martin took over the work done last year by Jelmer, in last year's
SoC.  This was a substanital task, as the the ldb modules API changed
significantly during the past year, with the addition of async calls.

This changeset reimplements and enables the ldb_map ldb module and
adapts the example module and test case, both named samba3sam, to the
implementation.

The ldb_map module supports splitting an ldb database into two parts
(called the "local" and "remote" part) and storing the data in one of
them (the remote database) in a different format while the other acts
as a fallback.
This allows ldb to e.g. store to and load data from a remote LDAP
server and present it according to the Samba4 schema while still
allowing the LDAP to present and modify its data separately.

A complex example of this is the samba3sam module (by Jelmer
Vernooij), which maps data between the samba3 and samba4 schemas.

A simpler example is given by the entryUUID module (by Andrew
Bartlett), which handles some of the differences between AD and
OpenLDAP in operational attributes.  It principally maps objectGUID,
to and from entryUUID elements.  This is also an example of a module
that doesn't use the local backend as fallback storage.

This merge also splits the ldb_map.c file into smaller, more
manageable parts.
(This used to be commit af2bece4d343a9f787b2e3628848b266cec2b9f0)

1 files changed, 118 insertions, 0 deletions

diff --git a/source4/lib/ldb/modules/ldb_map_private.h b/source4/lib/ldb/modules/ldb_map_private.h
new file mode 100644
index 0000000000..1b21fcf558
--- /dev/null
+++ b/source4/lib/ldb/modules/ldb_map_private.h
@@ -0,0 +1,118 @@
+
+/* A handy macro to report Out of Memory conditions */
+#define map_oom(module) ldb_set_errstring(module->ldb, talloc_asprintf(module, "Out of Memory"));
+
+/* The type of search callback functions */
+typedef int (*ldb_search_callback)(struct ldb_context *, void *, struct ldb_reply *);
+
+/* The special DN from which the local and remote base DNs are fetched */
+#define MAP_DN_NAME	"@MAP"
+#define MAP_DN_FROM	"@FROM"
+#define MAP_DN_TO	"@TO"
+
+/* Private data structures
+ * ======================= */
+
+/* Global private data */
+struct map_private {
+	struct ldb_map_context context;
+};
+
+/* Context data for mapped requests */
+struct map_context {
+	enum map_step {
+		MAP_SEARCH_REMOTE,
+		MAP_ADD_REMOTE,
+		MAP_ADD_LOCAL,
+		MAP_SEARCH_SELF_MODIFY,
+		MAP_MODIFY_REMOTE,
+		MAP_MODIFY_LOCAL,
+		MAP_SEARCH_SELF_DELETE,
+		MAP_DELETE_REMOTE,
+		MAP_DELETE_LOCAL,
+		MAP_SEARCH_SELF_RENAME,
+		MAP_RENAME_REMOTE,
+		MAP_RENAME_FIXUP,
+		MAP_RENAME_LOCAL
+	} step;
+
+	struct ldb_module *module;
+
+	const struct ldb_dn *local_dn;
+	const struct ldb_parse_tree *local_tree;
+	const char * const *local_attrs;
+
+	struct ldb_request *orig_req;
+	struct ldb_request *local_req;
+	struct ldb_request *remote_req;
+	struct ldb_request *down_req;
+	struct ldb_request *search_req;
+
+	/* for search, we may have a lot of contexts */
+	int num_searches;
+	struct ldb_request **search_reqs;
+};
+
+/* Context data for mapped search requests */
+struct map_search_context {
+	struct map_context *ac;
+	struct ldb_reply *local_res;
+	struct ldb_reply *remote_res;
+};
+
+
+/* Common operations
+ * ================= */
+
+/* The following definitions come from lib/ldb/modules/ldb_map.c */
+const struct ldb_map_context *map_get_context(struct ldb_module *module);
+struct map_search_context *map_init_search_context(struct map_context *ac, struct ldb_reply *ares);
+struct ldb_handle *map_init_handle(struct ldb_request *req, struct ldb_module *module);
+
+int ldb_next_remote_request(struct ldb_module *module, struct ldb_request *request);
+
+BOOL map_check_local_db(struct ldb_module *module);
+BOOL map_attr_check_remote(const struct ldb_map_context *data, const char *attr);
+BOOL ldb_dn_check_local(struct ldb_module *module, const struct ldb_dn *dn);
+
+const struct ldb_map_attribute *map_attr_find_local(const struct ldb_map_context *data, const char *name);
+const struct ldb_map_attribute *map_attr_find_remote(const struct ldb_map_context *data, const char *name);
+
+const char *map_attr_map_local(void *mem_ctx, const struct ldb_map_attribute *map, const char *attr);
+const char *map_attr_map_remote(void *mem_ctx, const struct ldb_map_attribute *map, const char *attr);
+
+struct ldb_val ldb_val_map_local(struct ldb_module *module, void *mem_ctx, const struct ldb_map_attribute *map, struct ldb_val val);
+struct ldb_val ldb_val_map_remote(struct ldb_module *module, void *mem_ctx, const struct ldb_map_attribute *map, struct ldb_val val);
+
+struct ldb_dn *ldb_dn_map_local(struct ldb_module *module, void *mem_ctx, const struct ldb_dn *dn);
+struct ldb_dn *ldb_dn_map_remote(struct ldb_module *module, void *mem_ctx, const struct ldb_dn *dn);
+struct ldb_dn *ldb_dn_map_rebase_remote(struct ldb_module *module, void *mem_ctx, const struct ldb_dn *dn);
+
+struct ldb_request *map_search_base_req(struct map_context *ac, const struct ldb_dn *dn, const char * const *attrs, const struct ldb_parse_tree *tree, void *context, ldb_search_callback callback);
+struct ldb_request *map_search_self_req(struct map_context *ac, const struct ldb_dn *dn);
+struct ldb_request *map_build_fixup_req(struct map_context *ac, const struct ldb_dn *olddn, const struct ldb_dn *newdn);
+
+
+/* LDB Requests
+ * ============ */
+
+/* The following definitions come from lib/ldb/modules/ldb_map_inbound.c */
+int map_add_do_remote(struct ldb_handle *handle);
+int map_add_do_local(struct ldb_handle *handle);
+int map_add(struct ldb_module *module, struct ldb_request *req);
+
+int map_modify_do_remote(struct ldb_handle *handle);
+int map_modify_do_local(struct ldb_handle *handle);
+int map_modify(struct ldb_module *module, struct ldb_request *req);
+
+int map_delete_do_remote(struct ldb_handle *handle);
+int map_delete_do_local(struct ldb_handle *handle);
+int map_delete(struct ldb_module *module, struct ldb_request *req);
+
+int map_rename_do_remote(struct ldb_handle *handle);
+int map_rename_do_fixup(struct ldb_handle *handle);
+int map_rename_do_local(struct ldb_handle *handle);
+int map_rename(struct ldb_module *module, struct ldb_request *req);
+
+/* The following definitions come from lib/ldb/modules/ldb_map_outbound.c */
+int map_search(struct ldb_module *module, struct ldb_request *req);