| /** |
| * 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.LinkedList; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.Set; |
| import java.util.HashSet; |
| import java.util.StringTokenizer; |
| import java.util.concurrent.ConcurrentHashMap; |
| |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.hadoop.classification.InterfaceStability; |
| |
| import org.apache.commons.logging.Log; |
| import org.apache.commons.logging.LogFactory; |
| import org.apache.hadoop.util.Shell; |
| import org.apache.hadoop.util.Shell.ExitCodeException; |
| |
| import org.apache.hadoop.security.NetgroupCache; |
| |
| /** |
| * A simple shell-based implementation of {@link GroupMappingServiceProvider} |
| * that exec's the <code>groups</code> shell command to fetch the group |
| * memberships of a given user. |
| */ |
| @InterfaceAudience.LimitedPrivate({"HDFS", "MapReduce"}) |
| @InterfaceStability.Evolving |
| public class ShellBasedUnixGroupsNetgroupMapping |
| extends ShellBasedUnixGroupsMapping { |
| |
| private static final Log LOG = |
| LogFactory.getLog(ShellBasedUnixGroupsNetgroupMapping.class); |
| |
| /** |
| * Get unix groups (parent) and netgroups for given user |
| * |
| * @param user get groups and netgroups for this user |
| * @return groups and netgroups for user |
| */ |
| @Override |
| public List<String> getGroups(String user) throws IOException { |
| // parent get 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 |
| } |
| } |
| } |
| |
| /** |
| * Gets users for a netgroup |
| * |
| * @param netgroup return users for this netgroup |
| * @return list of users for a given netgroup |
| */ |
| protected List<String> getUsersForNetgroup(String netgroup) |
| throws IOException { |
| |
| List<String> users = new LinkedList<String>(); |
| |
| // returns a string similar to this: |
| // group ( , user, ) ( domain, user1, host.com ) |
| String usersRaw = execShellGetUserForNetgroup(netgroup); |
| // get rid of spaces, makes splitting much easier |
| usersRaw = usersRaw.replaceAll(" +", ""); |
| // remove netgroup name at the beginning of the string |
| usersRaw = usersRaw.replaceFirst( |
| netgroup.replaceFirst("@", "") + "[()]+", |
| ""); |
| // split string into user infos |
| String[] userInfos = usersRaw.split("[()]+"); |
| for(String userInfo : userInfos) { |
| // userInfo: xxx,user,yyy (xxx, yyy can be empty strings) |
| // get rid of everything before first and after last comma |
| String user = userInfo.replaceFirst("[^,]*,", ""); |
| user = user.replaceFirst(",.*$", ""); |
| // voila! got username! |
| users.add(user); |
| } |
| |
| return users; |
| } |
| |
| /** |
| * Calls shell to get users for a netgroup by calling getent |
| * netgroup, this is a low level function that just returns string |
| * that |
| * |
| * @param netgroup get users for this netgroup |
| * @return string of users for a given netgroup in getent netgroups format |
| */ |
| protected String execShellGetUserForNetgroup(final String netgroup) |
| throws IOException { |
| String result = ""; |
| try { |
| // shell command does not expect '@' at the begining of the group name |
| result = Shell.execCommand( |
| Shell.getUsersForNetgroupCommand(netgroup.substring(1))); |
| } catch (ExitCodeException e) { |
| // if we didn't get the group - just return empty list; |
| LOG.warn("error getting users for netgroup " + netgroup, e); |
| } |
| return result; |
| } |
| } |