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 REPLY packet class, a server sends an Reply message containing assigned leases
27  * and configuration parameters in response to a Solicit, Request, Renew or Rebind messages
28  * received from a client.
29  *
30  * https://tools.ietf.org/html/rfc8415#page-24
31  */
32 public class Dhcp6ReplyPacket extends Dhcp6Packet {
33     /**
34      * Generates a reply packet with the specified parameters.
35      */
Dhcp6ReplyPacket(int transId, @NonNull final byte[] clientDuid, @NonNull final byte[] serverDuid, final byte[] iapd, boolean rapidCommit)36     Dhcp6ReplyPacket(int transId, @NonNull final byte[] clientDuid,
37             @NonNull final byte[] serverDuid, final byte[] iapd, boolean rapidCommit) {
38         super(transId, 0 /* elapsedTime */, clientDuid, serverDuid, iapd);
39         mRapidCommit = rapidCommit;
40     }
41 
42     /**
43      * Build a DHCPv6 Reply message with the specific parameters.
44      */
buildPacket()45     public ByteBuffer buildPacket() {
46         final ByteBuffer packet = ByteBuffer.allocate(DHCP_MAX_LENGTH);
47         final int msgTypeAndTransId = (DHCP6_MESSAGE_TYPE_REPLY << 24) | mTransId;
48         packet.putInt(msgTypeAndTransId);
49 
50         addTlv(packet, DHCP6_CLIENT_IDENTIFIER, mClientDuid);
51         addTlv(packet, DHCP6_SERVER_IDENTIFIER, mServerDuid);
52         addTlv(packet, DHCP6_IA_PD, mIaPd);
53         if (mRapidCommit) {
54             addTlv(packet, DHCP6_RAPID_COMMIT);
55         }
56 
57         packet.flip();
58         return packet;
59     }
60 }
61