| /* |
| * Copyright (C) 2010 The Android Open Source Project |
| * |
| * Licensed 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 android.net.dhcp; |
| |
| import java.net.InetAddress; |
| import java.net.Inet4Address; |
| import java.nio.ByteBuffer; |
| import java.util.List; |
| |
| /** |
| * This class implements the DHCP-ACK packet. |
| */ |
| class DhcpAckPacket extends DhcpPacket { |
| |
| /** |
| * The address of the server which sent this packet. |
| */ |
| private final InetAddress mSrcIp; |
| |
| DhcpAckPacket(int transId, boolean broadcast, InetAddress serverAddress, |
| InetAddress clientIp, byte[] clientMac) { |
| super(transId, Inet4Address.ANY, clientIp, Inet4Address.ANY, |
| Inet4Address.ANY, clientMac, broadcast); |
| mBroadcast = broadcast; |
| mSrcIp = serverAddress; |
| } |
| |
| public String toString() { |
| String s = super.toString(); |
| String dnsServers = " DNS servers: "; |
| |
| for (InetAddress dnsServer: mDnsServers) { |
| dnsServers += dnsServer.toString() + " "; |
| } |
| |
| return s + " ACK: your new IP " + mYourIp + |
| ", netmask " + mSubnetMask + |
| ", gateway " + mGateway + dnsServers + |
| ", lease time " + mLeaseTime; |
| } |
| |
| /** |
| * Fills in a packet with the requested ACK parameters. |
| */ |
| public ByteBuffer buildPacket(int encap, short destUdp, short srcUdp) { |
| ByteBuffer result = ByteBuffer.allocate(MAX_LENGTH); |
| InetAddress destIp = mBroadcast ? Inet4Address.ALL : mYourIp; |
| InetAddress srcIp = mBroadcast ? Inet4Address.ANY : mSrcIp; |
| |
| fillInPacket(encap, destIp, srcIp, destUdp, srcUdp, result, |
| DHCP_BOOTREPLY, mBroadcast); |
| result.flip(); |
| return result; |
| } |
| |
| /** |
| * Adds the optional parameters to the client-generated ACK packet. |
| */ |
| void finishPacket(ByteBuffer buffer) { |
| addTlv(buffer, DHCP_MESSAGE_TYPE, DHCP_MESSAGE_TYPE_ACK); |
| addTlv(buffer, DHCP_SERVER_IDENTIFIER, mServerIdentifier); |
| addTlv(buffer, DHCP_LEASE_TIME, mLeaseTime); |
| |
| // the client should renew at 1/2 the lease-expiry interval |
| if (mLeaseTime != null) { |
| addTlv(buffer, DHCP_RENEWAL_TIME, |
| Integer.valueOf(mLeaseTime.intValue() / 2)); |
| } |
| |
| addTlv(buffer, DHCP_SUBNET_MASK, mSubnetMask); |
| addTlv(buffer, DHCP_ROUTER, mGateway); |
| addTlv(buffer, DHCP_DOMAIN_NAME, mDomainName); |
| addTlv(buffer, DHCP_BROADCAST_ADDRESS, mBroadcastAddress); |
| addTlv(buffer, DHCP_DNS_SERVER, mDnsServers); |
| addTlvEnd(buffer); |
| } |
| |
| /** |
| * Un-boxes an Integer, returning 0 if a null reference is supplied. |
| */ |
| private static final int getInt(Integer v) { |
| if (v == null) { |
| return 0; |
| } else { |
| return v.intValue(); |
| } |
| } |
| |
| /** |
| * Notifies the specified state machine of the ACK packet parameters. |
| */ |
| public void doNextOp(DhcpStateMachine machine) { |
| machine.onAckReceived(mYourIp, mSubnetMask, mGateway, mDnsServers, |
| mServerIdentifier, getInt(mLeaseTime)); |
| } |
| } |