001/**
002* Licensed to the Apache Software Foundation (ASF) under one
003* or more contributor license agreements.  See the NOTICE file
004* distributed with this work for additional information
005* regarding copyright ownership.  The ASF licenses this file
006* to you under the Apache License, Version 2.0 (the
007* "License"); you may not use this file except in compliance
008* with the License.  You may obtain a copy of the License at
009*
010*     http://www.apache.org/licenses/LICENSE-2.0
011*
012* Unless required by applicable law or agreed to in writing, software
013* distributed under the License is distributed on an "AS IS" BASIS,
014* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015* See the License for the specific language governing permissions and
016* limitations under the License.
017*/
018
019package org.apache.hadoop.yarn.security.client;
020
021import java.util.Collection;
022
023import org.apache.commons.logging.Log;
024import org.apache.commons.logging.LogFactory;
025import org.apache.hadoop.classification.InterfaceAudience.Public;
026import org.apache.hadoop.classification.InterfaceStability.Stable;
027import org.apache.hadoop.io.Text;
028import org.apache.hadoop.security.token.Token;
029import org.apache.hadoop.security.token.TokenIdentifier;
030import org.apache.hadoop.security.token.TokenSelector;
031
032@Public
033@Stable
034public class RMDelegationTokenSelector implements
035    TokenSelector<RMDelegationTokenIdentifier> {
036
037  private static final Log LOG = LogFactory
038      .getLog(RMDelegationTokenSelector.class);
039
040  private boolean checkService(Text service,
041      Token<? extends TokenIdentifier> token) {
042    if (service == null || token.getService() == null) {
043      return false;
044    }
045    return token.getService().toString().contains(service.toString());
046  }
047
048  @SuppressWarnings("unchecked")
049  public Token<RMDelegationTokenIdentifier> selectToken(Text service,
050      Collection<Token<? extends TokenIdentifier>> tokens) {
051    if (service == null) {
052      return null;
053    }
054    LOG.debug("Looking for a token with service " + service.toString());
055    for (Token<? extends TokenIdentifier> token : tokens) {
056      LOG.debug("Token kind is " + token.getKind().toString()
057          + " and the token's service name is " + token.getService());
058      if (RMDelegationTokenIdentifier.KIND_NAME.equals(token.getKind())
059          && checkService(service, token)) {
060        return (Token<RMDelegationTokenIdentifier>) token;
061      }
062    }
063    return null;
064  }
065
066}