org.apache.hadoop.fs.DefaultFileAccess Maven / Gradle / Ivy
/**
* 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.fs;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.security.AccessControlException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.EnumSet;
import java.util.List;
import javax.security.auth.login.LoginException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.permission.FsAction;
import org.apache.hadoop.fs.permission.FsPermission;
import org.apache.hadoop.hive.shims.ShimLoader;
import org.apache.hadoop.hive.shims.Utils;
import org.apache.hadoop.security.UserGroupInformation;
/**
* Implements the default file access logic for HadoopShims.checkFileAccess(), for Hadoop
* versions which do not implement FileSystem.access().
*
*/
public class DefaultFileAccess {
private static Logger LOG = LoggerFactory.getLogger(DefaultFileAccess.class);
private static List emptyGroups = new ArrayList(0);
public static void checkFileAccess(FileSystem fs, FileStatus stat, FsAction action)
throws IOException, AccessControlException, LoginException {
// Get the user/groups for checking permissions based on the current UGI.
UserGroupInformation currentUgi = Utils.getUGI();
DefaultFileAccess.checkFileAccess(fs, stat, action,
currentUgi.getShortUserName(),
Arrays.asList(currentUgi.getGroupNames()));
}
public static void checkFileAccess(FileSystem fs, FileStatus stat, FsAction action,
String user, List groups) throws IOException, AccessControlException {
if (groups == null) {
groups = emptyGroups;
}
String superGroupName = getSuperGroupName(fs.getConf());
if (userBelongsToSuperGroup(superGroupName, groups)) {
LOG.info("User \"" + user + "\" belongs to super-group \"" + superGroupName + "\". " +
"Permission granted for action: " + action + ".");
return;
}
final FsPermission dirPerms = stat.getPermission();
final String grp = stat.getGroup();
if (user.equals(stat.getOwner())) {
if (dirPerms.getUserAction().implies(action)) {
return;
}
} else if (groups.contains(grp)) {
if (dirPerms.getGroupAction().implies(action)) {
return;
}
} else if (dirPerms.getOtherAction().implies(action)) {
return;
}
throw new AccessControlException("action " + action + " not permitted on path "
+ stat.getPath() + " for user " + user);
}
private static String getSuperGroupName(Configuration configuration) {
return configuration.get("dfs.permissions.supergroup", "");
}
private static boolean userBelongsToSuperGroup(String superGroupName, List groups) {
return groups.contains(superGroupName);
}
}