| /** |
| * 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.ArrayList; |
| import java.util.Collections; |
| import java.util.LinkedHashSet; |
| import java.util.List; |
| import java.util.Set; |
| import java.util.StringTokenizer; |
| import java.util.concurrent.TimeUnit; |
| |
| import org.apache.hadoop.thirdparty.com.google.common.annotations.VisibleForTesting; |
| import org.apache.hadoop.thirdparty.com.google.common.base.Joiner; |
| import org.apache.commons.lang3.StringUtils; |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.hadoop.classification.InterfaceStability; |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.conf.Configured; |
| import org.apache.hadoop.fs.CommonConfigurationKeys; |
| import org.apache.hadoop.util.Shell; |
| import org.apache.hadoop.util.Shell.ExitCodeException; |
| import org.apache.hadoop.util.Shell.ShellCommandExecutor; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** |
| * 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 ShellBasedUnixGroupsMapping extends Configured |
| implements GroupMappingServiceProvider { |
| |
| @VisibleForTesting |
| protected static final Logger LOG = |
| LoggerFactory.getLogger(ShellBasedUnixGroupsMapping.class); |
| |
| private long timeout = CommonConfigurationKeys. |
| HADOOP_SECURITY_GROUP_SHELL_COMMAND_TIMEOUT_DEFAULT; |
| private static final Set<String> EMPTY_GROUPS_SET = Collections.emptySet(); |
| |
| @Override |
| public void setConf(Configuration conf) { |
| super.setConf(conf); |
| if (conf != null) { |
| timeout = conf.getTimeDuration( |
| CommonConfigurationKeys. |
| HADOOP_SECURITY_GROUP_SHELL_COMMAND_TIMEOUT_KEY, |
| CommonConfigurationKeys. |
| HADOOP_SECURITY_GROUP_SHELL_COMMAND_TIMEOUT_DEFAULT, |
| TimeUnit.MILLISECONDS); |
| } |
| } |
| |
| @SuppressWarnings("serial") |
| private static class PartialGroupNameException extends IOException { |
| public PartialGroupNameException(String message) { |
| super(message); |
| } |
| |
| public PartialGroupNameException(String message, Throwable err) { |
| super(message, err); |
| } |
| |
| @Override |
| public String toString() { |
| final StringBuilder sb = |
| new StringBuilder("PartialGroupNameException "); |
| sb.append(super.getMessage()); |
| return sb.toString(); |
| } |
| } |
| /** |
| * Returns list of groups for a user |
| * |
| * @param userName get groups for this user |
| * @return list of groups for a given user |
| */ |
| @Override |
| public List<String> getGroups(String userName) throws IOException { |
| return new ArrayList(getUnixGroups(userName)); |
| } |
| |
| /** |
| * Caches groups, no need to do that for this provider |
| */ |
| @Override |
| public void cacheGroupsRefresh() throws IOException { |
| // does nothing in this provider of user to groups mapping |
| } |
| |
| /** |
| * Adds groups to cache, no need to do that for this provider |
| * |
| * @param groups unused |
| */ |
| @Override |
| public void cacheGroupsAdd(List<String> groups) throws IOException { |
| // does nothing in this provider of user to groups mapping |
| } |
| |
| @Override |
| public Set<String> getGroupsSet(String userName) throws IOException { |
| return getUnixGroups(userName); |
| } |
| |
| /** |
| * Create a ShellCommandExecutor object using the user's name. |
| * |
| * @param userName user's name |
| * @return a ShellCommandExecutor object |
| */ |
| protected ShellCommandExecutor createGroupExecutor(String userName) { |
| return new ShellCommandExecutor( |
| getGroupsForUserCommand(userName), null, null, timeout); |
| } |
| |
| /** |
| * Returns just the shell command to be used to fetch a user's groups list. |
| * This is mainly separate to make some tests easier. |
| * @param userName The username that needs to be passed into the command built |
| * @return An appropriate shell command with arguments |
| */ |
| protected String[] getGroupsForUserCommand(String userName) { |
| return Shell.getGroupsForUserCommand(userName); |
| } |
| |
| /** |
| * Create a ShellCommandExecutor object for fetch a user's group id list. |
| * |
| * @param userName the user's name |
| * @return a ShellCommandExecutor object |
| */ |
| protected ShellCommandExecutor createGroupIDExecutor(String userName) { |
| return new ShellCommandExecutor( |
| getGroupsIDForUserCommand(userName), null, null, timeout); |
| } |
| |
| /** |
| * Returns just the shell command to be used to fetch a user's group IDs list. |
| * This is mainly separate to make some tests easier. |
| * @param userName The username that needs to be passed into the command built |
| * @return An appropriate shell command with arguments |
| */ |
| protected String[] getGroupsIDForUserCommand(String userName) { |
| return Shell.getGroupsIDForUserCommand(userName); |
| } |
| |
| /** |
| * Check if the executor had a timeout and logs the event. |
| * @param executor to check |
| * @param user user to log |
| * @return true if timeout has occurred |
| */ |
| private boolean handleExecutorTimeout( |
| ShellCommandExecutor executor, |
| String user) { |
| // If its a shell executor timeout, indicate so in the message |
| // but treat the result as empty instead of throwing it up, |
| // similar to how partial resolution failures are handled above |
| if (executor.isTimedOut()) { |
| LOG.warn( |
| "Unable to return groups for user '{}' as shell group lookup " + |
| "command '{}' ran longer than the configured timeout limit of " + |
| "{} seconds.", |
| user, |
| Joiner.on(' ').join(executor.getExecString()), |
| timeout |
| ); |
| return true; |
| } |
| return false; |
| } |
| |
| /** |
| * Get the current user's group list from Unix by running the command 'groups' |
| * NOTE. For non-existing user it will return EMPTY list. |
| * |
| * @param user get groups for this user |
| * @return the groups list that the <code>user</code> belongs to. The primary |
| * group is returned first. |
| * @throws IOException if encounter any error when running the command |
| */ |
| private Set<String> getUnixGroups(String user) throws IOException { |
| ShellCommandExecutor executor = createGroupExecutor(user); |
| |
| Set<String> groups; |
| try { |
| executor.execute(); |
| groups = resolveFullGroupNames(executor.getOutput()); |
| } catch (ExitCodeException e) { |
| if (handleExecutorTimeout(executor, user)) { |
| return EMPTY_GROUPS_SET; |
| } else { |
| try { |
| groups = resolvePartialGroupNames(user, e.getMessage(), |
| executor.getOutput()); |
| } catch (PartialGroupNameException pge) { |
| LOG.warn("unable to return groups for user {}", user, pge); |
| return EMPTY_GROUPS_SET; |
| } |
| } |
| } catch (IOException ioe) { |
| if (handleExecutorTimeout(executor, user)) { |
| return EMPTY_GROUPS_SET; |
| } else { |
| // If its not an executor timeout, we should let the caller handle it |
| throw ioe; |
| } |
| } |
| return groups; |
| } |
| |
| /** |
| * Attempt to parse group names given that some names are not resolvable. |
| * Use the group id list to identify those that are not resolved. |
| * |
| * @param groupNames a string representing a list of group names |
| * @param groupIDs a string representing a list of group ids |
| * @return a linked list of group names |
| * @throws PartialGroupNameException |
| */ |
| private Set<String> parsePartialGroupNames(String groupNames, |
| String groupIDs) throws PartialGroupNameException { |
| StringTokenizer nameTokenizer = |
| new StringTokenizer(groupNames, Shell.TOKEN_SEPARATOR_REGEX); |
| StringTokenizer idTokenizer = |
| new StringTokenizer(groupIDs, Shell.TOKEN_SEPARATOR_REGEX); |
| Set<String> groups = new LinkedHashSet<>(); |
| while (nameTokenizer.hasMoreTokens()) { |
| // check for unresolvable group names. |
| if (!idTokenizer.hasMoreTokens()) { |
| throw new PartialGroupNameException("Number of group names and ids do" |
| + " not match. group name =" + groupNames + ", group id = " + groupIDs); |
| } |
| String groupName = nameTokenizer.nextToken(); |
| String groupID = idTokenizer.nextToken(); |
| if (!StringUtils.isNumeric(groupName) || |
| !groupName.equals(groupID)) { |
| // if the group name is non-numeric, it is resolved. |
| // if the group name is numeric, but is not the same as group id, |
| // regard it as a group name. |
| // if unfortunately, some group names are not resolvable, and |
| // the group name is the same as the group id, regard it as not |
| // resolved. |
| groups.add(groupName); |
| } |
| } |
| return groups; |
| } |
| |
| /** |
| * Attempt to partially resolve group names. |
| * |
| * @param userName the user's name |
| * @param errMessage error message from the shell command |
| * @param groupNames the incomplete list of group names |
| * @return a set of resolved group names |
| * @throws PartialGroupNameException if the resolution fails or times out |
| */ |
| private Set<String> resolvePartialGroupNames(String userName, |
| String errMessage, String groupNames) throws PartialGroupNameException { |
| // Exception may indicate that some group names are not resolvable. |
| // Shell-based implementation should tolerate unresolvable groups names, |
| // and return resolvable ones, similar to what JNI-based implementation |
| // does. |
| if (Shell.WINDOWS) { |
| throw new PartialGroupNameException("Does not support partial group" |
| + " name resolution on Windows. " + errMessage); |
| } |
| if (groupNames.isEmpty()) { |
| throw new PartialGroupNameException("The user name '" + userName |
| + "' is not found. " + errMessage); |
| } else { |
| LOG.warn("Some group names for '{}' are not resolvable. {}", |
| userName, errMessage); |
| // attempt to partially resolve group names |
| ShellCommandExecutor partialResolver = createGroupIDExecutor(userName); |
| try { |
| partialResolver.execute(); |
| return parsePartialGroupNames( |
| groupNames, partialResolver.getOutput()); |
| } catch (ExitCodeException ece) { |
| // If exception is thrown trying to get group id list, |
| // something is terribly wrong, so give up. |
| throw new PartialGroupNameException( |
| "failed to get group id list for user '" + userName + "'", ece); |
| } catch (IOException ioe) { |
| String message = |
| "Can't execute the shell command to " + |
| "get the list of group id for user '" + userName + "'"; |
| if (partialResolver.isTimedOut()) { |
| message += |
| " because of the command taking longer than " + |
| "the configured timeout: " + timeout + " seconds"; |
| } |
| throw new PartialGroupNameException(message, ioe); |
| } |
| } |
| } |
| |
| /** |
| * Split group names into a set. |
| * |
| * @param groupNames a string representing the user's group names |
| * @return a set of group names |
| */ |
| @VisibleForTesting |
| protected Set<String> resolveFullGroupNames(String groupNames) { |
| StringTokenizer tokenizer = |
| new StringTokenizer(groupNames, Shell.TOKEN_SEPARATOR_REGEX); |
| Set<String> groups = new LinkedHashSet<>(); |
| while (tokenizer.hasMoreTokens()) { |
| groups.add(tokenizer.nextToken()); |
| } |
| |
| return groups; |
| } |
| } |