content: //
  // 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 com.cloud.hypervisor.kvm.resource.wrapper;
  
  import java.net.InetAddress;
  import java.net.InterfaceAddress;
  import java.net.NetworkInterface;
  import java.net.SocketException;
  import java.util.Enumeration;
  
  import com.cloud.agent.api.Answer;
  import com.cloud.agent.api.OvsFetchInterfaceAnswer;
  import com.cloud.agent.api.OvsFetchInterfaceCommand;
  import com.cloud.hypervisor.kvm.resource.LibvirtComputingResource;
  import com.cloud.resource.CommandWrapper;
  import com.cloud.resource.ResourceWrapper;
  import com.cloud.utils.Ternary;
  
  @ResourceWrapper(handles =  OvsFetchInterfaceCommand.class)
  public final class LibvirtOvsFetchInterfaceCommandWrapper extends CommandWrapper<OvsFetchInterfaceCommand, Answer, LibvirtComputingResource> {
  
  
      private String getSubnetMaskForAddress(NetworkInterface networkInterface, InetAddress inetAddress) {
          for (InterfaceAddress address : networkInterface.getInterfaceAddresses()) {
              if (!inetAddress.equals(address.getAddress())) {
                  continue;
              }
              int prefixLength = address.getNetworkPrefixLength();
              int mask = 0xffffffff << (32 - prefixLength);
              return String.format("%d.%d.%d.%d",
                      (mask >>> 24) & 0xff,
                      (mask >>> 16) & 0xff,
                      (mask >>> 8) & 0xff,
                      mask & 0xff);
          }
          return "";
      }
  
      private String getMacAddress(NetworkInterface networkInterface) throws SocketException {
          byte[] macBytes = networkInterface.getHardwareAddress();
          if (macBytes == null) {
              return "";
          }
          StringBuilder macAddress = new StringBuilder();
          for (byte b : macBytes) {
              macAddress.append(String.format("%02X:", b));
          }
          if (macAddress.length() > 0) {
              macAddress.deleteCharAt(macAddress.length() - 1);  // Remove trailing colon
          }
          return macAddress.toString();
      }
  
      public Ternary<String, String, String> getInterfaceDetails(String interfaceName) throws SocketException {
          NetworkInterface networkInterface = NetworkInterface.getByName(interfaceName);
          if (networkInterface == null) {
              logger.warn(String.format("Network interface: '%s' not found", interfaceName));
              return new Ternary<>(null, null, null);
          }
          Enumeration<InetAddress> inetAddresses = networkInterface.getInetAddresses();
          while (inetAddresses.hasMoreElements()) {
              InetAddress inetAddress = inetAddresses.nextElement();
              if (inetAddress instanceof java.net.Inet4Address) {
                  String ipAddress = inetAddress.getHostAddress();
                  String subnetMask = getSubnetMaskForAddress(networkInterface, inetAddress);
                  String macAddress = getMacAddress(networkInterface);
                  return new Ternary<>(ipAddress, subnetMask, macAddress);
              }
          }
          return new Ternary<>(null, null, null);
      }
  
      @Override
      public Answer execute(final OvsFetchInterfaceCommand command, final LibvirtComputingResource libvirtComputingResource) {
          final String label = command.getLabel();
  
          logger.debug("Will look for network with name-label:" + label);
          try {
              Ternary<String, String, String> interfaceDetails = getInterfaceDetails(label);
              return new OvsFetchInterfaceAnswer(command, true, "Interface " + label
                      + " retrieved successfully", interfaceDetails.first(), interfaceDetails.second(),
                      interfaceDetails.third());
  
          } catch (final Exception e) {
              logger.warn("Caught execption when fetching interface", e);
              return new OvsFetchInterfaceAnswer(command, false, "EXCEPTION:"
                      + e.getMessage());
          }
      }
  }
  