1 /* 2 * Copyright (C) 2023 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.dhcp6; 18 19 import static com.android.net.module.util.NetworkStackConstants.DHCP_MAX_LENGTH; 20 21 import androidx.annotation.NonNull; 22 23 import java.nio.ByteBuffer; 24 25 /** 26 * DHCPv6 REBIND packet class, a client sends a Rebind message to any available server to extend 27 * the lifetimes on the leases assigned to the client and to update other configuration parameters. 28 * This message is sent after a client receives no response to a Renew message. 29 * 30 * https://tools.ietf.org/html/rfc8415#page-24 31 */ 32 public class Dhcp6RebindPacket extends Dhcp6Packet { 33 /** 34 * Generates a rebind packet with the specified parameters. 35 */ Dhcp6RebindPacket(int transId, int elapsedTime, @NonNull final byte[] clientDuid, @NonNull final byte[] iapd)36 Dhcp6RebindPacket(int transId, int elapsedTime, @NonNull final byte[] clientDuid, 37 @NonNull final byte[] iapd) { 38 super(transId, elapsedTime, clientDuid, null /* serverDuid */, iapd); 39 } 40 41 /** 42 * Build a DHCPv6 Rebind message with the specific parameters. 43 */ buildPacket()44 public ByteBuffer buildPacket() { 45 final ByteBuffer packet = ByteBuffer.allocate(DHCP_MAX_LENGTH); 46 final int msgTypeAndTransId = (DHCP6_MESSAGE_TYPE_REBIND << 24) | mTransId; 47 packet.putInt(msgTypeAndTransId); 48 49 addTlv(packet, DHCP6_CLIENT_IDENTIFIER, getClientDuid()); 50 addTlv(packet, DHCP6_ELAPSED_TIME, (short) (mElapsedTime & 0xFFFF)); 51 addTlv(packet, DHCP6_IA_PD, mIaPd); 52 53 packet.flip(); 54 return packet; 55 } 56 } 57