/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.hadoop.hbase.security.access;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.hbase.classification.InterfaceAudience;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.hbase.zookeeper.ZKUtil;
import org.apache.hadoop.hbase.zookeeper.ZooKeeperListener;
import org.apache.hadoop.hbase.zookeeper.ZooKeeperWatcher;
import org.apache.zookeeper.KeeperException;
import java.io.IOException;
import java.util.List;
import java.util.concurrent.CountDownLatch;
/**
* Handles synchronization of access control list entries and updates
* throughout all nodes in the cluster. The {@link AccessController} instance
* on the {@code _acl_} table regions, creates a znode for each table as
* {@code /hbase/acl/tablename}, with the znode data containing a serialized
* list of the permissions granted for the table. The {@code AccessController}
* instances on all other cluster hosts watch the znodes for updates, which
* trigger updates in the {@link TableAuthManager} permission cache.
*/
@InterfaceAudience.Private
public class ZKPermissionWatcher extends ZooKeeperListener {
private static Log LOG = LogFactory.getLog(ZKPermissionWatcher.class);
// parent node for permissions lists
static final String ACL_NODE = "acl";
TableAuthManager authManager;
String aclZNode;
CountDownLatch initialized = new CountDownLatch(1);
public ZKPermissionWatcher(ZooKeeperWatcher watcher,
TableAuthManager authManager, Configuration conf) {
super(watcher);
this.authManager = authManager;
String aclZnodeParent = conf.get("zookeeper.znode.acl.parent", ACL_NODE);
this.aclZNode = ZKUtil.joinZNode(watcher.baseZNode, aclZnodeParent);
}
public void start() throws KeeperException {
try {
watcher.registerListener(this);
if (ZKUtil.watchAndCheckExists(watcher, aclZNode)) {
List<ZKUtil.NodeAndData> existing =
ZKUtil.getChildDataAndWatchForNewChildren(watcher, aclZNode);
if (existing != null) {
refreshNodes(existing);
}
}
} finally {
initialized.countDown();
}
}
private void waitUntilStarted() {
try {
initialized.await();
} catch (InterruptedException e) {
LOG.warn("Interrupted while waiting", e);
Thread.currentThread().interrupt();
}
}
@Override
public void nodeCreated(String path) {
waitUntilStarted();
if (path.equals(aclZNode)) {
try {
List<ZKUtil.NodeAndData> nodes =
ZKUtil.getChildDataAndWatchForNewChildren(watcher, aclZNode);
refreshNodes(nodes);
} catch (KeeperException ke) {
LOG.error("Error reading data from zookeeper", ke);
// only option is to abort
watcher.abort("Zookeeper error obtaining acl node children", ke);
}
}
}
@Override
public void nodeDeleted(String path) {
waitUntilStarted();
if (aclZNode.equals(ZKUtil.getParent(path))) {
String table = ZKUtil.getNodeName(path);
if(AccessControlLists.isNamespaceEntry(table)) {
authManager.removeNamespace(Bytes.toBytes(table));
} else {
authManager.removeTable(TableName.valueOf(table));
}
}
}
@Override
public void nodeDataChanged(String path) {
waitUntilStarted();
if (aclZNode.equals(ZKUtil.getParent(path))) {
// update cache on an existing table node
String entry = ZKUtil.getNodeName(path);
try {
byte[] data = ZKUtil.getDataAndWatch(watcher, path);
refreshAuthManager(entry, data);
} catch (KeeperException ke) {
LOG.error("Error reading data from zookeeper for node " + entry, ke);
// only option is to abort
watcher.abort("Zookeeper error getting data for node " + entry, ke);
} catch (IOException ioe) {
LOG.error("Error reading permissions writables", ioe);
}
}
}
@Override
public void nodeChildrenChanged(String path) {
waitUntilStarted();
if (path.equals(aclZNode)) {
// table permissions changed
try {
List<ZKUtil.NodeAndData> nodes =
ZKUtil.getChildDataAndWatchForNewChildren(watcher, aclZNode);
refreshNodes(nodes);
} catch (KeeperException ke) {
LOG.error("Error reading data from zookeeper for path "+path, ke);
watcher.abort("Zookeeper error get node children for path "+path, ke);
}
}
}
private void refreshNodes(List<ZKUtil.NodeAndData> nodes) {
for (ZKUtil.NodeAndData n : nodes) {
if (n.isEmpty()) continue;
String path = n.getNode();
String entry = (ZKUtil.getNodeName(path));
try {
refreshAuthManager(entry, n.getData());
} catch (IOException ioe) {
LOG.error("Failed parsing permissions for table '" + entry +
"' from zk", ioe);
}
}
}
private void refreshAuthManager(String entry, byte[] nodeData) throws IOException {
if (LOG.isDebugEnabled()) {
LOG.debug("Updating permissions cache from node "+entry+" with data: "+
Bytes.toStringBinary(nodeData));
}
if(AccessControlLists.isNamespaceEntry(entry)) {
authManager.refreshNamespaceCacheFromWritable(
AccessControlLists.fromNamespaceEntry(entry), nodeData);
} else {
authManager.refreshTableCacheFromWritable(TableName.valueOf(entry), nodeData);
}
}
/***
* Write a table's access controls to the permissions mirror in zookeeper
* @param entry
* @param permsData
*/
public void writeToZookeeper(byte[] entry, byte[] permsData) {
String entryName = Bytes.toString(entry);
String zkNode = ZKUtil.joinZNode(watcher.baseZNode, ACL_NODE);
zkNode = ZKUtil.joinZNode(zkNode, entryName);
try {
ZKUtil.createWithParents(watcher, zkNode);
ZKUtil.updateExistingNodeData(watcher, zkNode, permsData, -1);
} catch (KeeperException e) {
LOG.error("Failed updating permissions for entry '" +
entryName + "'", e);
watcher.abort("Failed writing node "+zkNode+" to zookeeper", e);
}
}
/***
* Delete the acl notify node of table
* @param tableName
*/
public void deleteTableACLNode(final TableName tableName) {
String zkNode = ZKUtil.joinZNode(watcher.baseZNode, ACL_NODE);
zkNode = ZKUtil.joinZNode(zkNode, tableName.getNameAsString());
try {
ZKUtil.deleteNode(watcher, zkNode);
} catch (KeeperException.NoNodeException e) {
LOG.warn("No acl notify node of table '" + tableName + "'");
} catch (KeeperException e) {
LOG.error("Failed deleting acl node of table '" + tableName + "'", e);
watcher.abort("Failed deleting node " + zkNode, e);
}
}
}