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, 182 insertions, 0 deletions

diff --git a/source4/dsdb/samdb/ldb_modules/entryUUID.c b/source4/dsdb/samdb/ldb_modules/entryUUID.c
new file mode 100644
index 0000000000..5f7efc1681
--- /dev/null
+++ b/source4/dsdb/samdb/ldb_modules/entryUUID.c
@@ -0,0 +1,182 @@
+/* 
+   ldb database module
+
+   LDAP semantics mapping module
+
+   Copyright (C) Jelmer Vernooij 2005
+   Copyright (C) Andrew Bartlett <abartlet@samba.org> 2006
+
+   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 2 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, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+/* 
+   This module relies on ldb_map to do all the real work, but performs
+   some of the trivial mappings between AD semantics and that provided
+   by OpenLDAP and similar servers.
+*/
+
+#include "includes.h"
+#include "ldb/include/ldb.h"
+#include "ldb/include/ldb_private.h"
+#include "ldb/include/ldb_errors.h"
+#include "ldb/modules/ldb_map.h"
+
+#include "librpc/gen_ndr/ndr_misc.h"
+#include "librpc/ndr/libndr.h"
+
+static struct ldb_val encode_guid(struct ldb_module *module, TALLOC_CTX *ctx, const struct ldb_val *val)
+{
+	struct GUID guid;
+	NTSTATUS status = GUID_from_string((char *)val->data, &guid);
+	struct ldb_val out = data_blob(NULL, 0);
+
+	if (!NT_STATUS_IS_OK(status)) {
+		return out;
+	}
+	status = ndr_push_struct_blob(&out, ctx, &guid, 
+				      (ndr_push_flags_fn_t)ndr_push_GUID);
+	if (!NT_STATUS_IS_OK(status)) {
+		return out;
+	}
+
+	return out;
+}
+
+static struct ldb_val decode_guid(struct ldb_module *module, TALLOC_CTX *ctx, const struct ldb_val *val)
+{
+	struct GUID *guid;
+	NTSTATUS status;
+	struct ldb_val out = data_blob(NULL, 0);
+	
+	guid = talloc(ctx, struct GUID);
+	if (guid == NULL) {
+		return out;
+	}
+	status = ndr_pull_struct_blob(val, guid, guid, 
+				      (ndr_pull_flags_fn_t)ndr_pull_GUID);
+	if (!NT_STATUS_IS_OK(status)) {
+		talloc_free(guid);
+		return out;
+	}
+	out = data_blob_string_const(GUID_string(ctx, guid));
+	talloc_free(guid);
+	return out;
+}
+
+/* The backend holds binary sids, so just copy them back */
+static struct ldb_val sid_copy(struct ldb_module *module, TALLOC_CTX *ctx, const struct ldb_val *val)
+{
+	struct ldb_val out = data_blob(NULL, 0);
+	ldb_handler_copy(module->ldb, ctx, val, &out);
+
+	return out;
+}
+
+/* Ensure we always convert sids into binary, so the backend doesn't have to know about both forms */
+static struct ldb_val sid_always_binary(struct ldb_module *module, TALLOC_CTX *ctx, const struct ldb_val *val)
+{
+	struct ldb_val out = data_blob(NULL, 0);
+	const struct ldb_attrib_handler *handler = ldb_attrib_handler(module->ldb, "objectSid");
+	
+	if (handler->canonicalise_fn(module->ldb, ctx, val, &out) != LDB_SUCCESS) {
+		return data_blob(NULL, 0);
+	}
+
+	return out;
+}
+
+const struct ldb_map_attribute entryUUID_attributes[] = 
+{
+	/* objectGUID */
+	{
+		.local_name = "objectGUID",
+		.type = MAP_CONVERT,
+		.u = {
+			.convert = {
+				.remote_name = "entryUUID", 
+				.convert_local = decode_guid,
+				.convert_remote = encode_guid,
+			},
+		},
+	},
+	/* objectSid */
+	{
+		.local_name = "objectSid",
+		.type = MAP_CONVERT,
+		.u = {
+			.convert = {
+				.remote_name = "objectSid", 
+				.convert_local = sid_always_binary,
+				.convert_remote = sid_copy,
+			},
+		},
+	},
+	{
+		.local_name = "whenCreated",
+		.type = MAP_RENAME,
+		.u = {
+			.rename = {
+				 .remote_name = "createTimestamp"
+			 }
+		}
+	},
+	{
+		.local_name = "whenChanged",
+		.type = MAP_RENAME,
+		.u = {
+			.rename = {
+				 .remote_name = "modifyTimestamp"
+			 }
+		}
+	},
+	{
+		.local_name = "*",
+		.type = MAP_KEEP,
+	},
+	{
+		.local_name = NULL,
+	}
+};
+
+/* the context init function */
+static int entryUUID_init(struct ldb_module *module)
+{
+        int ret;
+
+	ret = ldb_map_init(module, entryUUID_attributes, NULL, NULL);
+        if (ret != LDB_SUCCESS)
+                return ret;
+
+        return ldb_next_init(module);
+}
+
+static struct ldb_module_ops entryUUID_ops = {
+	.name		   = "entryUUID",
+	.init_context	   = entryUUID_init,
+};
+
+/* the init function */
+int ldb_entryUUID_module_init(void)
+{
+	struct ldb_module_ops ops = ldb_map_get_ops();
+	entryUUID_ops.add	= ops.add;
+	entryUUID_ops.modify	= ops.modify;
+	entryUUID_ops.del	= ops.del;
+	entryUUID_ops.rename	= ops.rename;
+	entryUUID_ops.search	= ops.search;
+	entryUUID_ops.wait	= ops.wait;
+
+	return ldb_register_module(&entryUUID_ops);
+}