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 ADVERTISE packet class, a server sends an Advertise message to indicate that it's
27  * available for DHCP service, in response to a Solicit message received from a client.
28  *
29  * https://tools.ietf.org/html/rfc8415#page-24
30  */
31 public class Dhcp6AdvertisePacket extends Dhcp6Packet {
32     /**
33      * Generates an advertise packet with the specified parameters.
34      */
Dhcp6AdvertisePacket(int transId, @NonNull final byte[] clientDuid, @NonNull final byte[] serverDuid, final byte[] iapd)35     Dhcp6AdvertisePacket(int transId, @NonNull final byte[] clientDuid,
36             @NonNull final byte[] serverDuid, final byte[] iapd) {
37         super(transId, 0 /* elapsedTime */, clientDuid, serverDuid, iapd);
38     }
39 
40     /**
41      * Build a DHCPv6 Advertise 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_ADVERTISE << 24) | mTransId;
46         packet.putInt(msgTypeAndTransId);
47 
48         addTlv(packet, DHCP6_CLIENT_IDENTIFIER, mClientDuid);
49         addTlv(packet, DHCP6_SERVER_IDENTIFIER, mServerDuid);
50         addTlv(packet, DHCP6_IA_PD, mIaPd);
51 
52         packet.flip();
53         return packet;
54     }
55 }
56