/*************************************************************************
* 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.
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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*
* 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
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* 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.util.dns;
import static com.eucalyptus.util.dns.DnsResolvers.DnsRequest;
import java.net.InetAddress;
import java.util.List;
import java.util.NavigableSet;
import java.util.concurrent.TimeUnit;
import org.xbill.DNS.Name;
import org.xbill.DNS.Record;
import com.eucalyptus.bootstrap.Bootstrap;
import com.eucalyptus.bootstrap.Host;
import com.eucalyptus.bootstrap.Hosts;
import com.eucalyptus.component.Components;
import com.eucalyptus.component.ServiceConfiguration;
import com.eucalyptus.component.ServiceConfigurations;
import com.eucalyptus.component.id.Dns;
import com.eucalyptus.configurable.ConfigurableClass;
import com.eucalyptus.configurable.ConfigurableField;
import com.eucalyptus.util.Cidr;
import com.eucalyptus.util.CollectionUtils;
import com.eucalyptus.util.Internets;
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.google.common.base.Function;
import com.google.common.base.Functions;
import com.google.common.base.Objects;
import com.google.common.cache.CacheBuilder;
import com.google.common.cache.CacheLoader;
import com.google.common.collect.Iterables;
import com.google.common.collect.Lists;
import com.google.common.primitives.Ints;
@ConfigurableClass( root = "dns.ns",
description = "Options controlling DNS name resolution for the system's nameservers." )
public class NameserverResolver extends DnsResolver {
@ConfigurableField( description = "Enable the NS resolver. Note: dns.enable must also be 'true'", initial = "true" )
public static Boolean enabled = Boolean.TRUE;
private static final Function<InetAddress,Cidr> cidrLookup = CacheBuilder.newBuilder( )
.maximumSize( 64 )
.expireAfterWrite( 1, TimeUnit.MINUTES )
.build( CacheLoader.from( Functions.compose(
CollectionUtils.optionalOr( Cidr.of( 0, 0 ) ),
Internets.interfaceCidr( ) ) ) );
@Override
public boolean checkAccepts( final DnsRequest request ) {
final Record query = request.getQuery( );
final Name name = query.getName( );
if ( !Bootstrap.isOperational( ) || !enabled || !DomainNames.isSystemSubdomain( name ) ) {
return false;
} else if ( RequestType.A.apply( query ) ) {
return name.getLabelString( 0 ).matches( "ns[1-9]*" );
} else if ( RequestType.NS.apply( query ) ) {
return true;
} else {
return false;
}
}
@Override
public DnsResponse lookupRecords( DnsRequest request ) {
final Record query = request.getQuery( );
Name name = query.getName( );
if ( RequestType.A.apply( query ) && DomainNames.isSystemSubdomain( name ) ) {
String label0 = name.getLabelString( 0 );
if ( name.equals( Name.fromConstantString( label0 + "." + DomainNames.internalSubdomain( ) ) )
|| name.equals( Name.fromConstantString( label0 + "." + DomainNames.externalSubdomain( ) ) ) ) {
NavigableSet<ServiceConfiguration> nsServers = Components.lookup( Dns.class ).services( );
Integer index = Objects.firstNonNull( Ints.tryParse( label0.substring( 2 ) ), 1 );
if ( nsServers.size( ) >= index ) {
ServiceConfiguration conf = nsServers.toArray( new ServiceConfiguration[] {} )[index-1];
final Record addressRecord = DomainNameRecords.addressRecord(
query.getName( ),
maphost( request.getLocalAddress( ), conf.getInetAddress( ) ) );
return DnsResponse.forName( name ).answer( addressRecord );
}
}
} else if ( RequestType.NS.apply( query ) ) {
NavigableSet<ServiceConfiguration> nsServers = Components.lookup( Dns.class ).services( );
List<Record> aRecs = Lists.newArrayList( );
Name domain = DomainNames.isInternalSubdomain( name ) ? DomainNames.internalSubdomain( ) : DomainNames.externalSubdomain( );
int idx = 1;
for ( ServiceConfiguration conf : nsServers ) {
aRecs.add( DomainNameRecords.addressRecord(
Name.fromConstantString( "ns" + (idx++) + "." + domain ) ,
maphost( request.getLocalAddress( ), conf.getInetAddress( ) ) ) );
}
return DnsResponse.forName( name )
.withAdditional( aRecs )
.answer( DomainNameRecords.nameservers( name ) );
}
return null;
}
@Override
public String toString( ) {
return this.getClass( ).getSimpleName( );
}
public static class NameserverReverseResolver extends DnsResolver {
@Override
public boolean checkAccepts( DnsRequest request ) {
final Record query = request.getQuery( );
return RequestType.PTR.apply( query ) && Subnets.isSystemHostAddress( DomainNameRecords.inAddrArpaToInetAddress( query.getName( ) ) );
}
@Override
public DnsResponse lookupRecords( DnsRequest request ) {
final Record query = request.getQuery( );
final InetAddress hostAddr = DomainNameRecords.inAddrArpaToInetAddress( query.getName( ) );
final String hostAddress = hostAddr.getHostAddress( );
if ( Hosts.contains( hostAddress ) ) {
NavigableSet<ServiceConfiguration> nsServers = Components.lookup( Dns.class ).services( );
int index = nsServers.headSet( ServiceConfigurations.lookupByHost( Dns.class, hostAddr.getHostAddress( ) ) ).size( );
final Name nsName = Name.fromConstantString( "ns" + index + "." + DomainNames.externalSubdomain( ) );
final Record ptrRecord = DomainNameRecords.ptrRecord( nsName, hostAddr );
return DnsResponse.forName( query.getName( ) ).answer( ptrRecord );
}
// EUCA-10245: return zero answer so that the next reverse resolver would answer
return DnsResponse.forName( query.getName( ) ).answer();
}
}
@SuppressWarnings( "ConstantConditions" )
public static InetAddress maphost( final InetAddress listenerAddress,
final InetAddress hostAddress ) {
InetAddress result = hostAddress;
final Cidr cidr = cidrLookup.apply( listenerAddress );
if ( !cidr.apply( result ) ) {
final Host host = Hosts.lookup( hostAddress );
if ( host != null ) {
result = Iterables.tryFind( host.getHostAddresses( ), cidr ).or( result );
}
}
return result;
}
}