s3:locking: add leases_db infrastructure

Will enable us to solve the dynamic share path problem
with leases on [homes].

We're also able to give the correct error codes when a
lease key is re-used with a different file name.

Pair-Programmed-With: Jeremy Allison <jra@samba.org>

Signed-off-by: Volker Lendecke <vl@samba.org>
Signed-off-by: Jeremy Allison <jra@samba.org>
Reviewed-by: Stefan Metzmacher <metze@samba.org>
(cherry picked from commit 14fac5dbc05823562760ac424522fb39817ec062)

2 files changed, 433 insertions, 0 deletions

diff --git a/source3/locking/leases_db.c b/source3/locking/leases_db.c
new file mode 100644
index 00000000000..67c93ff5c78
--- /dev/null
+++ b/source3/locking/leases_db.c
@@ -0,0 +1,387 @@
+/*
+   Unix SMB/CIFS implementation.
+   Map lease keys to file ids
+   Copyright (C) Volker Lendecke 2013
+
+   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 "system/filesys.h"
+#include "locking/leases_db.h"
+#include "dbwrap/dbwrap.h"
+#include "dbwrap/dbwrap_open.h"
+#include "util_tdb.h"
+#include "ndr.h"
+#include "librpc/gen_ndr/ndr_leases_db.h"
+
+#undef DBGC_CLASS
+#define DBGC_CLASS DBGC_LOCKING
+
+/* the leases database handle */
+static struct db_context *leases_db;
+
+bool leases_db_init(bool read_only)
+{
+	if (leases_db) {
+		return true;
+	}
+
+	leases_db = db_open(NULL, lock_path("leases.tdb"), 0,
+			    TDB_DEFAULT|TDB_VOLATILE|TDB_CLEAR_IF_FIRST|
+			    TDB_INCOMPATIBLE_HASH,
+			    read_only ? O_RDONLY : O_RDWR|O_CREAT, 0644,
+			    DBWRAP_LOCK_ORDER_2, DBWRAP_FLAG_NONE);
+
+	if (leases_db == NULL) {
+		DEBUG(1, ("ERROR: Failed to initialise leases database\n"));
+		return false;
+	}
+
+	return true;
+}
+
+static bool leases_db_key(TALLOC_CTX *mem_ctx,
+			  const struct GUID *client_guid,
+			  const struct smb2_lease_key *lease_key,
+			  TDB_DATA *key)
+{
+	struct leases_db_key db_key = {
+		.client_guid = *client_guid,
+		.lease_key = *lease_key };
+	DATA_BLOB blob;
+	enum ndr_err_code ndr_err;
+
+	if (DEBUGLEVEL >= 10) {
+		DEBUG(10, ("%s:\n", __func__));
+		NDR_PRINT_DEBUG(leases_db_key, &db_key);
+	}
+
+	ndr_err = ndr_push_struct_blob(
+		&blob, mem_ctx, &db_key,
+		(ndr_push_flags_fn_t)ndr_push_leases_db_key);
+	if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+		DEBUG(10, ("%s: ndr_push_struct_blob_failed: %s\n",
+			   __func__, ndr_errstr(ndr_err)));
+		return false;
+	}
+
+	*key = make_tdb_data(blob.data, blob.length);
+	return true;
+}
+
+NTSTATUS leases_db_add(const struct GUID *client_guid,
+		       const struct smb2_lease_key *lease_key,
+		       const struct file_id *id,
+		       const char *filename,
+		       const char *stream_name)
+{
+	TDB_DATA db_key, db_value;
+	DATA_BLOB blob;
+	struct db_record *rec;
+	NTSTATUS status;
+	bool ok;
+	struct leases_db_value new_value;
+	struct leases_db_value *value = NULL;
+	enum ndr_err_code ndr_err;
+
+	if (!leases_db_init(false)) {
+		return NT_STATUS_INTERNAL_ERROR;
+	}
+
+	ok = leases_db_key(talloc_tos(), client_guid, lease_key, &db_key);
+	if (!ok) {
+		DEBUG(10, ("%s: leases_db_key failed\n", __func__));
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	rec = dbwrap_fetch_locked(leases_db, talloc_tos(), db_key);
+	TALLOC_FREE(db_key.dptr);
+	if (rec == NULL) {
+		return NT_STATUS_INTERNAL_ERROR;
+	}
+
+	db_value = dbwrap_record_get_value(rec);
+	if (db_value.dsize != 0) {
+		uint32_t i;
+
+		DEBUG(10, ("%s: record exists\n", __func__));
+
+		value = talloc(talloc_tos(), struct leases_db_value);
+		if (value == NULL) {
+			status = NT_STATUS_NO_MEMORY;
+			goto out;
+		}
+
+		blob.data = db_value.dptr;
+		blob.length = db_value.dsize;
+
+		ndr_err = ndr_pull_struct_blob_all(
+			&blob, value, value,
+			(ndr_pull_flags_fn_t)ndr_pull_leases_db_value);
+		if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+			DEBUG(10, ("%s: ndr_pull_struct_blob_failed: %s\n",
+				   __func__, ndr_errstr(ndr_err)));
+			status = ndr_map_error2ntstatus(ndr_err);
+			goto out;
+		}
+
+		/* id must be unique. */
+		for (i = 0; i < value->num_file_ids; i++) {
+			if (file_id_equal(id, &value->ids[i])) {
+				status = NT_STATUS_OBJECT_NAME_COLLISION;
+				goto out;
+			}
+		}
+
+		value->ids = talloc_realloc(value, value->ids, struct file_id,
+					value->num_file_ids + 1);
+		if (value->ids == NULL) {
+			status = NT_STATUS_NO_MEMORY;
+			goto out;
+		}
+		value->ids[value->num_file_ids] = *id;
+		value->num_file_ids += 1;
+
+	} else {
+		DEBUG(10, ("%s: new record\n", __func__));
+
+		new_value = (struct leases_db_value) {
+			.num_file_ids = 1,
+			.ids = discard_const_p(struct file_id, id),
+			.filename = filename,
+			.stream_name = stream_name,
+		};
+		value = &new_value;
+	}
+
+	ndr_err = ndr_push_struct_blob(
+		&blob, talloc_tos(), value,
+		(ndr_push_flags_fn_t)ndr_push_leases_db_value);
+	if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+		DEBUG(10, ("%s: ndr_push_struct_blob_failed: %s\n",
+			   __func__, ndr_errstr(ndr_err)));
+		status = ndr_map_error2ntstatus(ndr_err);
+		goto out;
+	}
+
+	if (DEBUGLEVEL >= 10) {
+		DEBUG(10, ("%s:\n", __func__));
+		NDR_PRINT_DEBUG(leases_db_value, value);
+	}
+
+	db_value = make_tdb_data(blob.data, blob.length);
+
+	status = dbwrap_record_store(rec, db_value, 0);
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(10, ("%s: dbwrap_record_store returned %s\n",
+			   __func__, nt_errstr(status)));
+	}
+
+  out:
+
+	if (value != &new_value) {
+		TALLOC_FREE(value);
+	}
+	TALLOC_FREE(rec);
+	return status;
+}
+
+NTSTATUS leases_db_del(const struct GUID *client_guid,
+		       const struct smb2_lease_key *lease_key,
+		       const struct file_id *id)
+{
+	TDB_DATA db_key, db_value;
+	struct db_record *rec;
+	NTSTATUS status;
+	struct leases_db_value *value;
+	enum ndr_err_code ndr_err;
+	DATA_BLOB blob;
+	uint32_t i;
+	bool ok;
+
+	if (!leases_db_init(false)) {
+		return NT_STATUS_INTERNAL_ERROR;
+	}
+
+	ok = leases_db_key(talloc_tos(), client_guid, lease_key, &db_key);
+	if (!ok) {
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	rec = dbwrap_fetch_locked(leases_db, talloc_tos(), db_key);
+	TALLOC_FREE(db_key.dptr);
+	if (rec == NULL) {
+		return NT_STATUS_NOT_FOUND;
+	}
+	db_value = dbwrap_record_get_value(rec);
+	if (db_value.dsize == 0) {
+		status = NT_STATUS_INTERNAL_ERROR;
+		goto out;
+	}
+
+	value = talloc(talloc_tos(), struct leases_db_value);
+	if (value == NULL) {
+		status = NT_STATUS_NO_MEMORY;
+		goto out;
+	}
+
+	blob.data = db_value.dptr;
+	blob.length = db_value.dsize;
+
+	ndr_err = ndr_pull_struct_blob_all(
+		&blob, value, value,
+		(ndr_pull_flags_fn_t)ndr_pull_leases_db_value);
+	if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+		DEBUG(10, ("%s: ndr_pull_struct_blob_failed: %s\n",
+			   __func__, ndr_errstr(ndr_err)));
+		status = ndr_map_error2ntstatus(ndr_err);
+		goto out;
+	}
+
+	/* id must exist. */
+	for (i = 0; i < value->num_file_ids; i++) {
+		if (file_id_equal(id, &value->ids[i])) {
+			break;
+		}
+	}
+
+	if (i == value->num_file_ids) {
+		status = NT_STATUS_NOT_FOUND;
+		goto out;
+	}
+
+	value->ids[i] = value->ids[value->num_file_ids-1];
+	value->num_file_ids -= 1;
+
+	if (value->num_file_ids == 0) {
+		DEBUG(10, ("%s: deleting record\n", __func__));
+		status = dbwrap_record_delete(rec);
+	} else {
+		DEBUG(10, ("%s: updating record\n", __func__));
+		ndr_err = ndr_push_struct_blob(
+			&blob, talloc_tos(), value,
+			(ndr_push_flags_fn_t)ndr_push_leases_db_value);
+		if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+			DEBUG(10, ("%s: ndr_push_struct_blob_failed: %s\n",
+				   __func__, ndr_errstr(ndr_err)));
+			status = ndr_map_error2ntstatus(ndr_err);
+			goto out;
+		}
+
+		if (DEBUGLEVEL >= 10) {
+			DEBUG(10, ("%s:\n", __func__));
+			NDR_PRINT_DEBUG(leases_db_value, value);
+		}
+
+		db_value = make_tdb_data(blob.data, blob.length);
+
+		status = dbwrap_record_store(rec, db_value, 0);
+		if (!NT_STATUS_IS_OK(status)) {
+			DEBUG(10, ("%s: dbwrap_record_store returned %s\n",
+				   __func__, nt_errstr(status)));
+		}
+	}
+
+  out:
+
+	TALLOC_FREE(value);
+	TALLOC_FREE(rec);
+	return status;
+}
+
+struct leases_db_fetch_state {
+	void (*parser)(uint32_t num_file_ids,
+			struct file_id *ids, const char *filename,
+			const char *stream_name, void *private_data);
+	void *private_data;
+	NTSTATUS status;
+};
+
+static void leases_db_parser(TDB_DATA key, TDB_DATA data, void *private_data)
+{
+	struct leases_db_fetch_state *state =
+		(struct leases_db_fetch_state *)private_data;
+	DATA_BLOB blob = { .data = data.dptr, .length = data.dsize };
+	enum ndr_err_code ndr_err;
+	struct leases_db_value *value;
+
+	value = talloc(talloc_tos(), struct leases_db_value);
+	if (value == NULL) {
+		state->status = NT_STATUS_NO_MEMORY;
+		return;
+	}
+
+	ndr_err = ndr_pull_struct_blob_all(
+		&blob, value, value,
+		(ndr_pull_flags_fn_t)ndr_pull_leases_db_value);
+	if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+		DEBUG(10, ("%s: ndr_pull_struct_blob_failed: %s\n",
+			   __func__, ndr_errstr(ndr_err)));
+		TALLOC_FREE(value);
+		state->status = ndr_map_error2ntstatus(ndr_err);
+		return;
+	}
+
+	if (DEBUGLEVEL >= 10) {
+		DEBUG(10, ("%s:\n", __func__));
+		NDR_PRINT_DEBUG(leases_db_value, value);
+	}
+
+	state->parser(value->num_file_ids,
+			value->ids, value->filename, value->stream_name,
+			state->private_data);
+
+	TALLOC_FREE(value);
+	state->status = NT_STATUS_OK;
+}
+
+NTSTATUS leases_db_parse(const struct GUID *client_guid,
+			 const struct smb2_lease_key *lease_key,
+			 void (*parser)(uint32_t num_file_ids,
+					struct file_id *ids,
+					const char *filename,
+					const char *stream_name,
+					void *private_data),
+			 void *private_data)
+{
+	TDB_DATA db_key;
+	struct leases_db_fetch_state state;
+	NTSTATUS status;
+	bool ok;
+
+	if (!leases_db_init(true)) {
+		return NT_STATUS_INTERNAL_ERROR;
+	}
+
+	ok = leases_db_key(talloc_tos(), client_guid, lease_key, &db_key);
+	if (!ok) {
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	state = (struct leases_db_fetch_state) {
+		.parser = parser,
+		.private_data = private_data,
+		.status = NT_STATUS_OK
+	};
+
+	status = dbwrap_parse_record(leases_db, db_key, leases_db_parser,
+				     &state);
+	TALLOC_FREE(db_key.dptr);
+	if (!NT_STATUS_IS_OK(status)) {
+		return status;
+	}
+	return state.status;
+}
diff --git a/source3/locking/leases_db.h b/source3/locking/leases_db.h
new file mode 100644
index 00000000000..f5703562046
--- /dev/null
+++ b/source3/locking/leases_db.h
@@ -0,0 +1,46 @@
+/*
+ *  Unix SMB/CIFS implementation.
+ *  leases.tdb functions
+ *
+ *  Copyright (C) Volker Lendecke 2014
+ *
+ *  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/>.
+ */
+
+#ifndef _LEASES_DB_H_
+#define _LEASES_DB_H_
+
+struct GUID;
+struct smb2_lease_key;
+struct file_id;
+
+bool leases_db_init(bool read_only);
+NTSTATUS leases_db_add(const struct GUID *client_guid,
+		       const struct smb2_lease_key *lease_key,
+		       const struct file_id *id,
+		       const char *filename,
+		       const char *stream_name);
+NTSTATUS leases_db_del(const struct GUID *client_guid,
+		       const struct smb2_lease_key *lease_key,
+		       const struct file_id *id);
+NTSTATUS leases_db_parse(const struct GUID *client_guid,
+			 const struct smb2_lease_key *lease_key,
+			 void (*parser)(uint32_t num_file_ids,
+					struct file_id *ids,
+					const char *filename,
+					const char *stream_name,
+					void *private_data),
+			 void *private_data);
+
+#endif /* _LEASES_DB_H_ */