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 REQUEST packet class, a client sends a Request message to request configuration
27  * parameters, including addresses and/or delegated prefixes from a specific server.
28  *
29  * https://tools.ietf.org/html/rfc8415#page-24
30  */
31 public class Dhcp6RequestPacket extends Dhcp6Packet {
32     /**
33      * Generates a request packet with the specified parameters.
34      */
Dhcp6RequestPacket(int transId, int elapsedTime, @NonNull final byte[] clientDuid, @NonNull final byte[] serverDuid, final byte[] iapd)35     Dhcp6RequestPacket(int transId, int elapsedTime, @NonNull final byte[] clientDuid,
36             @NonNull final byte[] serverDuid, final byte[] iapd) {
37         super(transId, elapsedTime, clientDuid, serverDuid, iapd);
38     }
39 
40     /**
41      * Build a DHCPv6 Request message with the specific parameters.
42      */
buildPacket()43     public ByteBuffer buildPacket() {
44         final ByteBuffer packet = ByteBuffer.allocate(DHCP_MAX_LENGTH);
45         final int msgTypeAndTransId = (DHCP6_MESSAGE_TYPE_REQUEST << 24) | mTransId;
46         packet.putInt(msgTypeAndTransId);
47 
48         addTlv(packet, DHCP6_SERVER_IDENTIFIER, mServerDuid);
49         addTlv(packet, DHCP6_CLIENT_IDENTIFIER, mClientDuid);
50         addTlv(packet, DHCP6_ELAPSED_TIME, (short) (mElapsedTime & 0xFFFF));
51         addTlv(packet, DHCP6_IA_PD, mIaPd);
52         addTlv(packet, DHCP6_OPTION_REQUEST_OPTION, DHCP6_SOL_MAX_RT);
53 
54         packet.flip();
55         return packet;
56     }
57 }
58