s3:smbd: add smbXsrv_version_* infrastructure

metze

3 files changed, 270 insertions, 0 deletions

diff --git a/source3/smbd/globals.h b/source3/smbd/globals.h
index 0164cb627d..2614ebe631 100644
--- a/source3/smbd/globals.h
+++ b/source3/smbd/globals.h
@@ -356,6 +356,9 @@ struct smbXsrv_connection {
 	uint64_t smbd_idle_profstamp;
 };
 
+NTSTATUS smbXsrv_version_global_init(const struct server_id *server_id);
+uint32_t smbXsrv_version_global_current(void);
+
 NTSTATUS smbXsrv_connection_init_tables(struct smbXsrv_connection *conn,
 					enum protocol_types protocol);
 
diff --git a/source3/smbd/server.c b/source3/smbd/server.c
index c1cc15e8c5..ee4538c4ed 100644
--- a/source3/smbd/server.c
+++ b/source3/smbd/server.c
@@ -1061,6 +1061,7 @@ extern void build_options(bool screen);
 	NTSTATUS status;
 	struct tevent_context *ev_ctx;
 	struct messaging_context *msg_ctx;
+	struct server_id server_id;
 	struct tevent_signal *se;
 	char *np_dir = NULL;
 
@@ -1377,6 +1378,12 @@ extern void build_options(bool screen);
 		exit(1);
 	}
 
+	server_id = messaging_server_id(msg_ctx);
+	status = smbXsrv_version_global_init(&server_id);
+	if (!NT_STATUS_IS_OK(status)) {
+		exit(1);
+	}
+
 	if (!sessionid_init()) {
 		exit(1);
 	}
diff --git a/source3/smbd/smbXsrv_version.c b/source3/smbd/smbXsrv_version.c
new file mode 100644
index 0000000000..8ba5e1fc98
--- /dev/null
+++ b/source3/smbd/smbXsrv_version.c
@@ -0,0 +1,260 @@
+/*
+   Unix SMB/CIFS implementation.
+
+   Copyright (C) Stefan Metzmacher 2012
+
+   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 "smbd/globals.h"
+#include "dbwrap/dbwrap.h"
+#include "dbwrap/dbwrap_open.h"
+#include "lib/util/util_tdb.h"
+#include "librpc/gen_ndr/ndr_smbXsrv.h"
+#include "serverid.h"
+
+/*
+ * This implements a version scheme for file server internal
+ * states. smbXsrv_version_global.tdb stores the possible
+ * and current versions of structure formats (struct smbXsrv_*_global)
+ * per cluster node.
+ *
+ * If the supported versions doesn't match a version of any
+ * of the other nodes, it refused to start.
+ *
+ * This should prevent silent corruption of the internal
+ * databases and structures, if two incompatible implementations
+ * read and write.
+ *
+ * In future this can be used to implement rolling code upgrades
+ * in a cluster, but for now it is simple.
+ */
+
+static struct db_context *smbXsrv_version_global_db_ctx = NULL;
+static uint32_t smbXsrv_version_global_current_version = UINT32_MAX;
+
+NTSTATUS smbXsrv_version_global_init(const struct server_id *server_id)
+{
+	const char *global_path = NULL;
+	struct db_context *db_ctx = NULL;
+	struct db_record *db_rec = NULL;
+	TDB_DATA key;
+	TDB_DATA val;
+	DATA_BLOB blob;
+	struct smbXsrv_version_globalB global_blob;
+	enum ndr_err_code ndr_err;
+	struct smbXsrv_version_global0 *global = NULL;
+	uint32_t i;
+	uint32_t num_valid = 0;
+	struct smbXsrv_version_node0 *valid = NULL;
+	struct smbXsrv_version_node0 *local_node = NULL;
+	bool exists;
+	NTSTATUS status;
+	const char *key_string = "smbXsrv_version_global";
+	TALLOC_CTX *frame;
+
+	if (smbXsrv_version_global_db_ctx != NULL) {
+		return NT_STATUS_OK;
+	}
+
+	frame = talloc_stackframe();
+
+	global_path = lock_path("smbXsrv_version_global.tdb");
+
+	db_ctx = db_open(NULL, global_path,
+			 0, /* hash_size */
+			 TDB_DEFAULT |
+			 TDB_CLEAR_IF_FIRST |
+			 TDB_INCOMPATIBLE_HASH,
+			 O_RDWR | O_CREAT, 0600,
+			 DBWRAP_LOCK_ORDER_1);
+	if (db_ctx == NULL) {
+		status = map_nt_error_from_unix_common(errno);
+		DEBUG(0,("smbXsrv_version_global_init: "
+			 "failed to open[%s] - %s\n",
+			 global_path, nt_errstr(status)));
+		TALLOC_FREE(frame);
+		return status;
+	}
+
+	key = string_term_tdb_data(key_string);
+
+	db_rec = dbwrap_fetch_locked(db_ctx, db_ctx, key);
+	if (db_rec == NULL) {
+		status = NT_STATUS_INTERNAL_DB_ERROR;
+		DEBUG(0,("smbXsrv_version_global_init: "
+			 "dbwrap_fetch_locked(%s) - %s\n",
+			 key_string, nt_errstr(status)));
+		TALLOC_FREE(frame);
+		return status;
+	}
+
+	val = dbwrap_record_get_value(db_rec);
+	if (val.dsize == 0) {
+		global = talloc_zero(frame, struct smbXsrv_version_global0);
+		if (global == NULL) {
+			DEBUG(0,("smbXsrv_version_global_init: "
+				 "talloc_zero failed - %s\n", __location__));
+			TALLOC_FREE(frame);
+			return NT_STATUS_NO_MEMORY;
+		}
+		ZERO_STRUCT(global_blob);
+		global_blob.version = SMBXSRV_VERSION_CURRENT;
+		global_blob.info.info0 = global;
+	} else {
+		blob = data_blob_const(val.dptr, val.dsize);
+
+		ndr_err = ndr_pull_struct_blob(&blob, frame, &global_blob,
+			(ndr_pull_flags_fn_t)ndr_pull_smbXsrv_version_globalB);
+		if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+			status = ndr_map_error2ntstatus(ndr_err);
+			DEBUG(0,("smbXsrv_version_global_init: "
+				 "ndr_pull_smbXsrv_version_globalB - %s\n",
+				 nt_errstr(status)));
+			TALLOC_FREE(frame);
+			return status;
+		}
+
+		switch (global_blob.version) {
+		case SMBXSRV_VERSION_0:
+			global = global_blob.info.info0;
+			if (global == NULL) {
+				status = NT_STATUS_INTERNAL_DB_CORRUPTION;
+				break;
+			}
+			status = NT_STATUS_OK;
+			break;
+		default:
+			status = NT_STATUS_REVISION_MISMATCH;
+			break;
+		}
+
+		if (!NT_STATUS_IS_OK(status)) {
+			DEBUG(0,("smbXsrv_version_global_init - %s\n",
+				 nt_errstr(status)));
+			NDR_PRINT_DEBUG(smbXsrv_version_globalB, &global_blob);
+			TALLOC_FREE(frame);
+			return status;
+		}
+	}
+
+	valid = talloc_zero_array(global,
+				  struct smbXsrv_version_node0,
+				  global->num_nodes + 1);
+	if (valid == NULL) {
+		DEBUG(0,("smbXsrv_version_global_init: "
+			 "talloc_zero_array failed - %s\n", __location__));
+		TALLOC_FREE(frame);
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	num_valid = 0;
+	for (i=0; i < global->num_nodes; i++) {
+		struct smbXsrv_version_node0 *n = &global->nodes[i];
+
+		exists = serverid_exists(&n->server_id);
+		if (!exists) {
+			continue;
+		}
+
+		if (n->min_version > n->max_version) {
+			status = NT_STATUS_INTERNAL_DB_CORRUPTION;
+			DEBUG(0,("smbXsrv_version_global_init - %s\n",
+				 nt_errstr(status)));
+			NDR_PRINT_DEBUG(smbXsrv_version_globalB, &global_blob);
+			TALLOC_FREE(frame);
+			return status;
+		}
+
+		if (n->min_version > global_blob.version) {
+			status = NT_STATUS_INTERNAL_DB_CORRUPTION;
+			DEBUG(0,("smbXsrv_version_global_init - %s\n",
+				 nt_errstr(status)));
+			NDR_PRINT_DEBUG(smbXsrv_version_globalB, &global_blob);
+			TALLOC_FREE(frame);
+			return status;
+		}
+
+		if (n->max_version < global_blob.version) {
+			status = NT_STATUS_INTERNAL_DB_CORRUPTION;
+			DEBUG(0,("smbXsrv_version_global_init - %s\n",
+				 nt_errstr(status)));
+			NDR_PRINT_DEBUG(smbXsrv_version_globalB, &global_blob);
+			TALLOC_FREE(frame);
+			return status;
+		}
+
+		valid[num_valid] = *n;
+		if (server_id->vnn == n->server_id.vnn) {
+			local_node = &valid[num_valid];
+		}
+		num_valid++;
+	}
+
+	if (local_node == NULL) {
+		local_node = &valid[num_valid];
+		num_valid++;
+	}
+
+	local_node->server_id = *server_id;
+	local_node->min_version = SMBXSRV_VERSION_0;
+	local_node->max_version = SMBXSRV_VERSION_CURRENT;
+	local_node->current_version = global_blob.version;
+
+	global->num_nodes = num_valid;
+	global->nodes = valid;
+
+	global_blob.seqnum += 1;
+	global_blob.info.info0 = global;
+
+	ndr_err = ndr_push_struct_blob(&blob, db_rec, &global_blob,
+			(ndr_push_flags_fn_t)ndr_push_smbXsrv_version_globalB);
+	if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+		status = ndr_map_error2ntstatus(ndr_err);
+		DEBUG(0,("smbXsrv_version_global_init: "
+			 "ndr_push_smbXsrv_version_globalB - %s\n",
+			 nt_errstr(status)));
+		TALLOC_FREE(frame);
+		return status;
+	}
+
+	val = make_tdb_data(blob.data, blob.length);
+	status = dbwrap_record_store(db_rec, val, TDB_REPLACE);
+	TALLOC_FREE(db_rec);
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(0,("smbXsrv_version_global_init: "
+			 "dbwrap_record_store - %s\n",
+			 nt_errstr(status)));
+		TALLOC_FREE(frame);
+		return status;
+	}
+
+	DEBUG(10,("smbXsrv_version_global_init\n"));
+	if (DEBUGLVL(10)) {
+		NDR_PRINT_DEBUG(smbXsrv_version_globalB, &global_blob);
+	}
+
+	smbXsrv_version_global_db_ctx = db_ctx;
+	smbXsrv_version_global_current_version = global_blob.version;
+
+	TALLOC_FREE(frame);
+	return NT_STATUS_OK;
+}
+
+uint32_t smbXsrv_version_global_current(void)
+{
+	return smbXsrv_version_global_current_version;
+}