001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.hbase.security.visibility;
019
020import java.io.IOException;
021import org.apache.hadoop.conf.Configuration;
022import org.apache.hadoop.hbase.zookeeper.ZKListener;
023import org.apache.hadoop.hbase.zookeeper.ZKUtil;
024import org.apache.hadoop.hbase.zookeeper.ZKWatcher;
025import org.apache.hadoop.hbase.zookeeper.ZNodePaths;
026import org.apache.yetus.audience.InterfaceAudience;
027import org.apache.zookeeper.KeeperException;
028import org.slf4j.Logger;
029import org.slf4j.LoggerFactory;
030
031/**
032 * A zk watcher that watches the labels table znode. This would create a znode
033 * /hbase/visibility_labels and will have a serialized form of a set of labels in the system.
034 */
035@InterfaceAudience.Private
036public class ZKVisibilityLabelWatcher extends ZKListener {
037
038  private static final Logger LOG = LoggerFactory.getLogger(ZKVisibilityLabelWatcher.class);
039  private static final String VISIBILITY_LABEL_ZK_PATH = "zookeeper.znode.visibility.label.parent";
040  private static final String DEFAULT_VISIBILITY_LABEL_NODE = "visibility/labels";
041  private static final String VISIBILITY_USER_AUTHS_ZK_PATH =
042    "zookeeper.znode.visibility.user.auths.parent";
043  private static final String DEFAULT_VISIBILITY_USER_AUTHS_NODE = "visibility/user_auths";
044
045  private VisibilityLabelsCache labelsCache;
046  private String labelZnode;
047  private String userAuthsZnode;
048
049  public ZKVisibilityLabelWatcher(ZKWatcher watcher, VisibilityLabelsCache labelsCache,
050    Configuration conf) {
051    super(watcher);
052    this.labelsCache = labelsCache;
053    String labelZnodeParent = conf.get(VISIBILITY_LABEL_ZK_PATH, DEFAULT_VISIBILITY_LABEL_NODE);
054    String userAuthsZnodeParent =
055      conf.get(VISIBILITY_USER_AUTHS_ZK_PATH, DEFAULT_VISIBILITY_USER_AUTHS_NODE);
056    this.labelZnode = ZNodePaths.joinZNode(watcher.getZNodePaths().baseZNode, labelZnodeParent);
057    this.userAuthsZnode =
058      ZNodePaths.joinZNode(watcher.getZNodePaths().baseZNode, userAuthsZnodeParent);
059  }
060
061  public void start() throws KeeperException {
062    watcher.registerListener(this);
063    ZKUtil.createWithParents(watcher, labelZnode);
064    ZKUtil.createWithParents(watcher, userAuthsZnode);
065    byte[] data = ZKUtil.getDataAndWatch(watcher, labelZnode);
066    if (data != null && data.length > 0) {
067      refreshVisibilityLabelsCache(data);
068    }
069    data = ZKUtil.getDataAndWatch(watcher, userAuthsZnode);
070    if (data != null && data.length > 0) {
071      refreshUserAuthsCache(data);
072    }
073  }
074
075  private void refreshVisibilityLabelsCache(byte[] data) {
076    try {
077      this.labelsCache.refreshLabelsCache(data);
078    } catch (IOException ioe) {
079      LOG.error("Failed parsing data from labels table " + " from zk", ioe);
080    }
081  }
082
083  private void refreshUserAuthsCache(byte[] data) {
084    try {
085      this.labelsCache.refreshUserAuthsCache(data);
086    } catch (IOException ioe) {
087      LOG.error("Failed parsing data from labels table " + " from zk", ioe);
088    }
089  }
090
091  @Override
092  public void nodeCreated(String path) {
093    if (path.equals(labelZnode) || path.equals(userAuthsZnode)) {
094      try {
095        ZKUtil.watchAndCheckExists(watcher, path);
096      } catch (KeeperException ke) {
097        LOG.error("Error setting watcher on node " + path, ke);
098        // only option is to abort
099        watcher.abort("ZooKeeper error obtaining label node children", ke);
100      }
101    }
102  }
103
104  @Override
105  public void nodeDeleted(String path) {
106    // There is no case of visibility labels path to get deleted.
107  }
108
109  @Override
110  public void nodeDataChanged(String path) {
111    if (path.equals(labelZnode) || path.equals(userAuthsZnode)) {
112      try {
113        watcher.syncOrTimeout(path);
114        byte[] data = ZKUtil.getDataAndWatch(watcher, path);
115        if (path.equals(labelZnode)) {
116          refreshVisibilityLabelsCache(data);
117        } else {
118          refreshUserAuthsCache(data);
119        }
120      } catch (KeeperException ke) {
121        LOG.error("Error reading data from zookeeper for node " + path, ke);
122        // only option is to abort
123        watcher.abort("ZooKeeper error getting data for node " + path, ke);
124      }
125    }
126  }
127
128  @Override
129  public void nodeChildrenChanged(String path) {
130    // We are not dealing with child nodes under the label znode or userauths znode.
131  }
132
133  /**
134   * Write a labels mirror or user auths mirror into zookeeper
135   * @param labelsOrUserAuths true for writing labels and false for user auths.
136   */
137  public void writeToZookeeper(byte[] data, boolean labelsOrUserAuths) {
138    String znode = this.labelZnode;
139    if (!labelsOrUserAuths) {
140      znode = this.userAuthsZnode;
141    }
142    try {
143      ZKUtil.updateExistingNodeData(watcher, znode, data, -1);
144    } catch (KeeperException e) {
145      LOG.error("Failed writing to " + znode, e);
146      watcher.abort("Failed writing node " + znode + " to zookeeper", e);
147    }
148  }
149}