[120] | 1 | /** |
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| 2 | * Licensed to the Apache Software Foundation (ASF) under one |
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| 3 | * or more contributor license agreements. See the NOTICE file |
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| 4 | * distributed with this work for additional information |
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| 5 | * regarding copyright ownership. The ASF licenses this file |
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| 6 | * to you under the Apache License, Version 2.0 (the |
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| 7 | * "License"); you may not use this file except in compliance |
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| 8 | * with the License. You may obtain a copy of the License at |
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| 9 | * |
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| 10 | * http://www.apache.org/licenses/LICENSE-2.0 |
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| 11 | * |
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| 12 | * Unless required by applicable law or agreed to in writing, software |
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| 13 | * distributed under the License is distributed on an "AS IS" BASIS, |
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| 14 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
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| 15 | * See the License for the specific language governing permissions and |
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| 16 | * limitations under the License. |
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| 17 | */ |
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| 18 | package org.apache.hadoop.security; |
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| 19 | |
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| 20 | import java.io.IOException; |
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| 21 | import java.security.AccessController; |
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| 22 | import java.security.Principal; |
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| 23 | import java.util.Set; |
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| 24 | |
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| 25 | import javax.security.auth.Subject; |
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| 26 | import javax.security.auth.login.LoginException; |
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| 27 | |
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| 28 | import org.apache.commons.logging.Log; |
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| 29 | import org.apache.commons.logging.LogFactory; |
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| 30 | import org.apache.hadoop.conf.Configuration; |
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| 31 | import org.apache.hadoop.io.Writable; |
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| 32 | |
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| 33 | /** A {@link Writable} abstract class for storing user and groups information. |
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| 34 | */ |
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| 35 | public abstract class UserGroupInformation implements Writable, Principal { |
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| 36 | public static final Log LOG = LogFactory.getLog(UserGroupInformation.class); |
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| 37 | private static UserGroupInformation LOGIN_UGI = null; |
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| 38 | |
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| 39 | private static final ThreadLocal<Subject> currentUser = |
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| 40 | new ThreadLocal<Subject>(); |
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| 41 | |
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| 42 | /** @return the {@link UserGroupInformation} for the current thread */ |
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| 43 | public static UserGroupInformation getCurrentUGI() { |
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| 44 | Subject user = getCurrentUser(); |
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| 45 | |
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| 46 | if (user == null) { |
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| 47 | user = currentUser.get(); |
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| 48 | if (user == null) { |
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| 49 | return null; |
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| 50 | } |
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| 51 | } |
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| 52 | |
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| 53 | Set<UserGroupInformation> ugiPrincipals = |
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| 54 | user.getPrincipals(UserGroupInformation.class); |
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| 55 | |
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| 56 | UserGroupInformation ugi = null; |
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| 57 | if (ugiPrincipals != null && ugiPrincipals.size() == 1) { |
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| 58 | ugi = ugiPrincipals.iterator().next(); |
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| 59 | if (ugi == null) { |
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| 60 | throw new RuntimeException("Cannot find _current user_ UGI in the Subject!"); |
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| 61 | } |
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| 62 | } else { |
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| 63 | throw new RuntimeException("Cannot resolve current user from subject, " + |
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| 64 | "which had " + ugiPrincipals.size() + |
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| 65 | " UGI principals!"); |
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| 66 | } |
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| 67 | return ugi; |
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| 68 | } |
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| 69 | |
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| 70 | /** |
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| 71 | * Set the {@link UserGroupInformation} for the current thread |
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| 72 | * @deprecated Use {@link #setCurrentUser(UserGroupInformation)} |
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| 73 | */ |
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| 74 | @Deprecated |
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| 75 | public static void setCurrentUGI(UserGroupInformation ugi) { |
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| 76 | setCurrentUser(ugi); |
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| 77 | } |
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| 78 | |
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| 79 | /** |
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| 80 | * Return the current user <code>Subject</code>. |
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| 81 | * @return the current user <code>Subject</code> |
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| 82 | */ |
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| 83 | static Subject getCurrentUser() { |
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| 84 | return Subject.getSubject(AccessController.getContext()); |
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| 85 | } |
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| 86 | |
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| 87 | /** |
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| 88 | * Set the {@link UserGroupInformation} for the current thread |
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| 89 | * WARNING - This method should be used only in test cases and other exceptional |
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| 90 | * cases! |
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| 91 | * @param ugi {@link UserGroupInformation} for the current thread |
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| 92 | */ |
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| 93 | public static void setCurrentUser(UserGroupInformation ugi) { |
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| 94 | Subject user = SecurityUtil.getSubject(ugi); |
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| 95 | currentUser.set(user); |
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| 96 | } |
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| 97 | |
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| 98 | /** Get username |
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| 99 | * |
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| 100 | * @return the user's name |
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| 101 | */ |
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| 102 | public abstract String getUserName(); |
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| 103 | |
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| 104 | /** Get the name of the groups that the user belong to |
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| 105 | * |
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| 106 | * @return an array of group names |
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| 107 | */ |
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| 108 | public abstract String[] getGroupNames(); |
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| 109 | |
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| 110 | /** Login and return a UserGroupInformation object. */ |
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| 111 | public static UserGroupInformation login(Configuration conf |
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| 112 | ) throws LoginException { |
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| 113 | if (LOGIN_UGI == null) { |
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| 114 | LOGIN_UGI = UnixUserGroupInformation.login(conf); |
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| 115 | } |
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| 116 | return LOGIN_UGI; |
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| 117 | } |
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| 118 | |
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| 119 | /** Read a {@link UserGroupInformation} from conf */ |
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| 120 | public static UserGroupInformation readFrom(Configuration conf |
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| 121 | ) throws IOException { |
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| 122 | try { |
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| 123 | return UnixUserGroupInformation.readFromConf(conf, |
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| 124 | UnixUserGroupInformation.UGI_PROPERTY_NAME); |
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| 125 | } catch (LoginException e) { |
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| 126 | throw (IOException)new IOException().initCause(e); |
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| 127 | } |
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| 128 | } |
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| 129 | } |
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