1 /* 2 * Copyright (C) 2010 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package android.net.dhcp; 18 19 import java.net.Inet4Address; 20 import java.nio.ByteBuffer; 21 22 /** 23 * This class implements the DHCP-DISCOVER packet. 24 */ 25 class DhcpDiscoverPacket extends DhcpPacket { 26 /** 27 * Generates a DISCOVER packet with the specified parameters. 28 */ 29 DhcpDiscoverPacket(int transId, short secs, byte[] clientMac, boolean broadcast) { 30 super(transId, secs, INADDR_ANY, INADDR_ANY, INADDR_ANY, INADDR_ANY, clientMac, broadcast); 31 } 32 33 public String toString() { 34 String s = super.toString(); 35 return s + " DISCOVER " + 36 (mBroadcast ? "broadcast " : "unicast "); 37 } 38 39 /** 40 * Fills in a packet with the requested DISCOVER parameters. 41 */ 42 public ByteBuffer buildPacket(int encap, short destUdp, short srcUdp) { 43 ByteBuffer result = ByteBuffer.allocate(MAX_LENGTH); 44 fillInPacket(encap, INADDR_BROADCAST, INADDR_ANY, destUdp, 45 srcUdp, result, DHCP_BOOTREQUEST, mBroadcast); 46 result.flip(); 47 return result; 48 } 49 50 /** 51 * Adds optional parameters to a DISCOVER packet. 52 */ 53 void finishPacket(ByteBuffer buffer) { 54 addTlv(buffer, DHCP_MESSAGE_TYPE, DHCP_MESSAGE_TYPE_DISCOVER); 55 addTlv(buffer, DHCP_CLIENT_IDENTIFIER, getClientId()); 56 addCommonClientTlvs(buffer); 57 addTlv(buffer, DHCP_PARAMETER_LIST, mRequestedParams); 58 addTlvEnd(buffer); 59 } 60 } 61
