| /** |
| * 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.security; |
| |
| import java.io.IOException; |
| import java.util.Arrays; |
| import java.util.List; |
| import java.util.LinkedList; |
| |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.hadoop.classification.InterfaceStability; |
| |
| import org.apache.hadoop.util.NativeCodeLoader; |
| |
| import org.apache.hadoop.security.NetgroupCache; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** |
| * A JNI-based implementation of {@link GroupMappingServiceProvider} |
| * that invokes libC calls to get the group |
| * memberships of a given user. |
| */ |
| @InterfaceAudience.LimitedPrivate({"HDFS", "MapReduce"}) |
| @InterfaceStability.Evolving |
| public class JniBasedUnixGroupsNetgroupMapping |
| extends JniBasedUnixGroupsMapping { |
| |
| private static final Logger LOG = |
| LoggerFactory.getLogger(JniBasedUnixGroupsNetgroupMapping.class); |
| |
| native String[] getUsersForNetgroupJNI(String group); |
| |
| static { |
| if (!NativeCodeLoader.isNativeCodeLoaded()) { |
| throw new RuntimeException("Bailing out since native library couldn't " + |
| "be loaded"); |
| } |
| LOG.debug("Using JniBasedUnixGroupsNetgroupMapping for Netgroup resolution"); |
| } |
| |
| /** |
| * Gets unix groups and netgroups for the user. |
| * |
| * It gets all unix groups as returned by id -Gn but it |
| * only returns netgroups that are used in ACLs (there is |
| * no way to get all netgroups for a given user, see |
| * documentation for getent netgroup) |
| */ |
| @Override |
| public List<String> getGroups(String user) throws IOException { |
| // parent gets unix groups |
| List<String> groups = new LinkedList<String>(super.getGroups(user)); |
| NetgroupCache.getNetgroups(user, groups); |
| return groups; |
| } |
| |
| /** |
| * Refresh the netgroup cache |
| */ |
| @Override |
| public void cacheGroupsRefresh() throws IOException { |
| List<String> groups = NetgroupCache.getNetgroupNames(); |
| NetgroupCache.clear(); |
| cacheGroupsAdd(groups); |
| } |
| |
| /** |
| * Add a group to cache, only netgroups are cached |
| * |
| * @param groups list of group names to add to cache |
| */ |
| @Override |
| public void cacheGroupsAdd(List<String> groups) throws IOException { |
| for(String group: groups) { |
| if(group.length() == 0) { |
| // better safe than sorry (should never happen) |
| } else if(group.charAt(0) == '@') { |
| if(!NetgroupCache.isCached(group)) { |
| NetgroupCache.add(group, getUsersForNetgroup(group)); |
| } |
| } else { |
| // unix group, not caching |
| } |
| } |
| } |
| |
| /** |
| * Calls JNI function to get users for a netgroup, since C functions |
| * are not reentrant we need to make this synchronized (see |
| * documentation for setnetgrent, getnetgrent and endnetgrent) |
| * |
| * @param netgroup return users for this netgroup |
| * @return list of users for a given netgroup |
| */ |
| protected synchronized List<String> getUsersForNetgroup(String netgroup) { |
| String[] users = null; |
| try { |
| // JNI code does not expect '@' at the beginning of the group name |
| users = getUsersForNetgroupJNI(netgroup.substring(1)); |
| } catch (Exception e) { |
| if (LOG.isDebugEnabled()) { |
| LOG.debug("Error getting users for netgroup " + netgroup, e); |
| } else { |
| LOG.info("Error getting users for netgroup " + netgroup + |
| ": " + e.getMessage()); |
| } |
| } |
| if (users != null && users.length != 0) { |
| return Arrays.asList(users); |
| } |
| return new LinkedList<String>(); |
| } |
| } |