| /** |
| * 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.authorize; |
| |
| import java.io.DataInput; |
| import java.io.DataOutput; |
| import java.io.IOException; |
| import java.util.Collection; |
| import java.util.HashSet; |
| import java.util.LinkedList; |
| import java.util.List; |
| |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.hadoop.classification.InterfaceStability; |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.io.Text; |
| import org.apache.hadoop.io.Writable; |
| import org.apache.hadoop.io.WritableFactories; |
| import org.apache.hadoop.io.WritableFactory; |
| import org.apache.hadoop.security.Groups; |
| import org.apache.hadoop.security.UserGroupInformation; |
| import org.apache.hadoop.util.StringUtils; |
| |
| /** |
| * Class representing a configured access control list. |
| */ |
| @InterfaceAudience.Public |
| @InterfaceStability.Evolving |
| public class AccessControlList implements Writable { |
| |
| static { // register a ctor |
| WritableFactories.setFactory |
| (AccessControlList.class, |
| new WritableFactory() { |
| @Override |
| public Writable newInstance() { return new AccessControlList(); } |
| }); |
| } |
| |
| // Indicates an ACL string that represents access to all users |
| public static final String WILDCARD_ACL_VALUE = "*"; |
| private static final int INITIAL_CAPACITY = 256; |
| |
| // Set of users who are granted access. |
| private Collection<String> users; |
| // Set of groups which are granted access |
| private Collection<String> groups; |
| // Whether all users are granted access. |
| private boolean allAllowed; |
| |
| private Groups groupsMapping = Groups.getUserToGroupsMappingService(new Configuration()); |
| |
| /** |
| * This constructor exists primarily for AccessControlList to be Writable. |
| */ |
| public AccessControlList() { |
| } |
| |
| /** |
| * Construct a new ACL from a String representation of the same. |
| * |
| * The String is a a comma separated list of users and groups. |
| * The user list comes first and is separated by a space followed |
| * by the group list. For e.g. "user1,user2 group1,group2" |
| * |
| * @param aclString String representation of the ACL |
| */ |
| public AccessControlList(String aclString) { |
| buildACL(aclString.split(" ", 2)); |
| } |
| |
| /** |
| * Construct a new ACL from String representation of users and groups |
| * |
| * The arguments are comma separated lists |
| * |
| * @param users comma separated list of users |
| * @param groups comma separated list of groups |
| */ |
| public AccessControlList(String users, String groups) { |
| buildACL(new String[] {users, groups}); |
| } |
| |
| /** |
| * Build ACL from the given two Strings. |
| * The Strings contain comma separated values. |
| * |
| * @param aclString build ACL from array of Strings |
| */ |
| private void buildACL(String[] userGroupStrings) { |
| users = new HashSet<String>(); |
| groups = new HashSet<String>(); |
| for (String aclPart : userGroupStrings) { |
| if (aclPart != null && isWildCardACLValue(aclPart)) { |
| allAllowed = true; |
| break; |
| } |
| } |
| if (!allAllowed) { |
| if (userGroupStrings.length >= 1 && userGroupStrings[0] != null) { |
| users = StringUtils.getTrimmedStringCollection(userGroupStrings[0]); |
| } |
| |
| if (userGroupStrings.length == 2 && userGroupStrings[1] != null) { |
| groups = StringUtils.getTrimmedStringCollection(userGroupStrings[1]); |
| groupsMapping.cacheGroupsAdd(new LinkedList<String>(groups)); |
| } |
| } |
| } |
| |
| /** |
| * Checks whether ACL string contains wildcard |
| * |
| * @param aclString check this ACL string for wildcard |
| * @return true if ACL string contains wildcard false otherwise |
| */ |
| private boolean isWildCardACLValue(String aclString) { |
| if (aclString.contains(WILDCARD_ACL_VALUE) && |
| aclString.trim().equals(WILDCARD_ACL_VALUE)) { |
| return true; |
| } |
| return false; |
| } |
| |
| public boolean isAllAllowed() { |
| return allAllowed; |
| } |
| |
| /** |
| * Add user to the names of users allowed for this service. |
| * |
| * @param user |
| * The user name |
| */ |
| public void addUser(String user) { |
| if (isWildCardACLValue(user)) { |
| throw new IllegalArgumentException("User " + user + " can not be added"); |
| } |
| if (!isAllAllowed()) { |
| users.add(user); |
| } |
| } |
| |
| /** |
| * Add group to the names of groups allowed for this service. |
| * |
| * @param group |
| * The group name |
| */ |
| public void addGroup(String group) { |
| if (isWildCardACLValue(group)) { |
| throw new IllegalArgumentException("Group " + group + " can not be added"); |
| } |
| if (!isAllAllowed()) { |
| List<String> groupsList = new LinkedList<String>(); |
| groupsList.add(group); |
| groupsMapping.cacheGroupsAdd(groupsList); |
| groups.add(group); |
| } |
| } |
| |
| /** |
| * Remove user from the names of users allowed for this service. |
| * |
| * @param user |
| * The user name |
| */ |
| public void removeUser(String user) { |
| if (isWildCardACLValue(user)) { |
| throw new IllegalArgumentException("User " + user + " can not be removed"); |
| } |
| if (!isAllAllowed()) { |
| users.remove(user); |
| } |
| } |
| |
| /** |
| * Remove group from the names of groups allowed for this service. |
| * |
| * @param group |
| * The group name |
| */ |
| public void removeGroup(String group) { |
| if (isWildCardACLValue(group)) { |
| throw new IllegalArgumentException("Group " + group |
| + " can not be removed"); |
| } |
| if (!isAllAllowed()) { |
| groups.remove(group); |
| } |
| } |
| |
| /** |
| * Get the names of users allowed for this service. |
| * @return the set of user names. the set must not be modified. |
| */ |
| public Collection<String> getUsers() { |
| return users; |
| } |
| |
| /** |
| * Get the names of user groups allowed for this service. |
| * @return the set of group names. the set must not be modified. |
| */ |
| public Collection<String> getGroups() { |
| return groups; |
| } |
| |
| /** |
| * Checks if a user represented by the provided {@link UserGroupInformation} |
| * is a member of the Access Control List |
| * @param ugi UserGroupInformation to check if contained in the ACL |
| * @return true if ugi is member of the list |
| */ |
| public final boolean isUserInList(UserGroupInformation ugi) { |
| if (allAllowed || users.contains(ugi.getShortUserName())) { |
| return true; |
| } else if (!groups.isEmpty()) { |
| for (String group : ugi.getGroups()) { |
| if (groups.contains(group)) { |
| return true; |
| } |
| } |
| } |
| return false; |
| } |
| |
| public boolean isUserAllowed(UserGroupInformation ugi) { |
| return isUserInList(ugi); |
| } |
| |
| /** |
| * Returns descriptive way of users and groups that are part of this ACL. |
| * Use {@link #getAclString()} to get the exact String that can be given to |
| * the constructor of AccessControlList to create a new instance. |
| */ |
| @Override |
| public String toString() { |
| String str = null; |
| |
| if (allAllowed) { |
| str = "All users are allowed"; |
| } |
| else if (users.isEmpty() && groups.isEmpty()) { |
| str = "No users are allowed"; |
| } |
| else { |
| String usersStr = null; |
| String groupsStr = null; |
| if (!users.isEmpty()) { |
| usersStr = users.toString(); |
| } |
| if (!groups.isEmpty()) { |
| groupsStr = groups.toString(); |
| } |
| |
| if (!users.isEmpty() && !groups.isEmpty()) { |
| str = "Users " + usersStr + " and members of the groups " |
| + groupsStr + " are allowed"; |
| } |
| else if (!users.isEmpty()) { |
| str = "Users " + usersStr + " are allowed"; |
| } |
| else {// users is empty array and groups is nonempty |
| str = "Members of the groups " |
| + groupsStr + " are allowed"; |
| } |
| } |
| |
| return str; |
| } |
| |
| /** |
| * Returns the access control list as a String that can be used for building a |
| * new instance by sending it to the constructor of {@link AccessControlList}. |
| */ |
| public String getAclString() { |
| StringBuilder sb = new StringBuilder(INITIAL_CAPACITY); |
| if (allAllowed) { |
| sb.append('*'); |
| } |
| else { |
| sb.append(getUsersString()); |
| sb.append(" "); |
| sb.append(getGroupsString()); |
| } |
| return sb.toString(); |
| } |
| |
| /** |
| * Serializes the AccessControlList object |
| */ |
| @Override |
| public void write(DataOutput out) throws IOException { |
| String aclString = getAclString(); |
| Text.writeString(out, aclString); |
| } |
| |
| /** |
| * Deserializes the AccessControlList object |
| */ |
| @Override |
| public void readFields(DataInput in) throws IOException { |
| String aclString = Text.readString(in); |
| buildACL(aclString.split(" ", 2)); |
| } |
| |
| /** |
| * Returns comma-separated concatenated single String of the set 'users' |
| * |
| * @return comma separated list of users |
| */ |
| private String getUsersString() { |
| return getString(users); |
| } |
| |
| /** |
| * Returns comma-separated concatenated single String of the set 'groups' |
| * |
| * @return comma separated list of groups |
| */ |
| private String getGroupsString() { |
| return getString(groups); |
| } |
| |
| /** |
| * Returns comma-separated concatenated single String of all strings of |
| * the given set |
| * |
| * @param strings set of strings to concatenate |
| */ |
| private String getString(Collection<String> strings) { |
| StringBuilder sb = new StringBuilder(INITIAL_CAPACITY); |
| boolean first = true; |
| for(String str: strings) { |
| if (!first) { |
| sb.append(","); |
| } else { |
| first = false; |
| } |
| sb.append(str); |
| } |
| return sb.toString(); |
| } |
| } |