/*************************************************************************
* Copyright 2009-2014 Eucalyptus Systems, Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 3 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see http://www.gnu.org/licenses/.
*
* Please contact Eucalyptus Systems, Inc., 6755 Hollister Ave., Goleta
* CA 93117, USA or visit http://www.eucalyptus.com/licenses/ if you need
* additional information or have any questions.
*
* This file may incorporate work covered under the following copyright
* and permission notice:
*
* Software License Agreement (BSD License)
*
* Copyright (c) 2008, Regents of the University of California
* All rights reserved.
*
* Redistribution and use of this software in source and binary forms,
* with or without modification, are permitted provided that the
* following conditions are met:
*
* Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE. USERS OF THIS SOFTWARE ACKNOWLEDGE
* THE POSSIBLE PRESENCE OF OTHER OPEN SOURCE LICENSED MATERIAL,
* COPYRIGHTED MATERIAL OR PATENTED MATERIAL IN THIS SOFTWARE,
* AND IF ANY SUCH MATERIAL IS DISCOVERED THE PARTY DISCOVERING
* IT MAY INFORM DR. RICH WOLSKI AT THE UNIVERSITY OF CALIFORNIA,
* SANTA BARBARA WHO WILL THEN ASCERTAIN THE MOST APPROPRIATE REMEDY,
* WHICH IN THE REGENTS' DISCRETION MAY INCLUDE, WITHOUT LIMITATION,
* REPLACEMENT OF THE CODE SO IDENTIFIED, LICENSING OF THE CODE SO
* IDENTIFIED, OR WITHDRAWAL OF THE CODE CAPABILITY TO THE EXTENT
* NEEDED TO COMPLY WITH ANY SUCH LICENSES OR RIGHTS.
************************************************************************
* @author chris grzegorczyk <grze@eucalyptus.com>
*/
package com.eucalyptus.compute.metadata;
import static com.eucalyptus.util.dns.DnsResolvers.DnsRequest;
import java.net.InetAddress;
import org.xbill.DNS.Name;
import org.xbill.DNS.Record;
import com.eucalyptus.bootstrap.Bootstrap;
import com.eucalyptus.component.id.Eucalyptus;
import com.eucalyptus.configurable.ConfigurableClass;
import com.eucalyptus.configurable.ConfigurableField;
import com.eucalyptus.util.Subnets;
import com.eucalyptus.util.dns.DnsResolvers.DnsResolver;
import com.eucalyptus.util.dns.DnsResolvers.DnsResponse;
import com.eucalyptus.util.dns.DnsResolvers.RequestType;
import com.eucalyptus.util.dns.DomainNameRecords;
import com.eucalyptus.util.dns.DomainNames;
import com.eucalyptus.vm.dns.InstanceDomainNames;
import com.google.common.collect.Lists;
@ConfigurableClass( root = "dns.instancedata",
description = "Options controlling DNS name resolution for the instance metadata service." )
public class InstanceDataDnsResolver extends DnsResolver {
@ConfigurableField( description = "Enable the instance-data resolver. Note: dns.enable must also be 'true'",
initial = "true" )
public static Boolean enabled = Boolean.TRUE;
private static final Name INSTANCE_DATA = Name.fromConstantString( "instance-data." );
private static final Name RELATIVE_INSTANCE_DATA = INSTANCE_DATA.relativize( Name.fromConstantString( "." ) );
private static final Name INSTANCE_PTR = Name.fromConstantString( "254.169.254.169.in-addr.arpa." );
private static final InetAddress METADATA_ADDR = DomainNameRecords.inAddrArpaToInetAddress( INSTANCE_PTR );
private static final Record PTR_RECORD = DomainNameRecords.ptrRecord( INSTANCE_DATA, METADATA_ADDR );
private static final Record ADDRESS_RECORD = DomainNameRecords.addressRecord( INSTANCE_DATA, METADATA_ADDR );
@Override
public boolean checkAccepts( DnsRequest request ) {
final Record query = request.getQuery( );
final InetAddress source = request.getRemoteAddress( );
final Name name = query.getName( );
if ( !Bootstrap.isOperational( ) || !enabled ) {
return false;
} else if ( RequestType.PTR.apply( query ) ) {
return name.equals( INSTANCE_PTR );
} else {
boolean nameMatch = false;
if ( INSTANCE_DATA.equals( name ) ) {
nameMatch = true;
} else if ( name.subdomain( DomainNames.internalSubdomain( ) )
&& RELATIVE_INSTANCE_DATA.equals( DomainNames.relativize( name, DomainNames.internalSubdomain( ) ) ) ) {
nameMatch = true;
} else if ( name.subdomain( DomainNames.internalSubdomain( Eucalyptus.class ) )
&& RELATIVE_INSTANCE_DATA.equals( DomainNames.relativize( name, DomainNames.internalSubdomain( Eucalyptus.class ) ) ) ) {
nameMatch = true;
} else if ( InstanceDomainNames.isInstanceSubdomain( name )
&& RELATIVE_INSTANCE_DATA.equals( DomainNames.relativize( name, InstanceDomainNames.lookupInstanceDomain( name ) ) ) ) {
nameMatch = true;
}
// subnet check can be slow, so put last
return nameMatch && Subnets.isSystemManagedAddress( source );
}
}
@Override
public DnsResponse lookupRecords( DnsRequest request ) {
final Record query = request.getQuery( );
final Name name = query.getName( );
if ( RequestType.A.apply( query ) ) {
final String label0 = name.getLabelString( 0 );
if ( INSTANCE_DATA.getLabelString( 0 ).equals( label0 ) ) {
return DnsResponse.forName( name )
.answer( ADDRESS_RECORD );
}
} else if ( RequestType.PTR.apply( query ) && INSTANCE_PTR.equals( query.getName( ) ) ) {
return DnsResponse.forName( name )
.answer( PTR_RECORD );
} else {
return DnsResponse.forName( name ).answer( Lists.<Record>newArrayList());
}
return null;
}
@Override
public String toString( ) {
return this.getClass( ).getSimpleName( );
}
}