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.nsd;
18 
19 import android.annotation.FlaggedApi;
20 import android.annotation.LongDef;
21 import android.annotation.NonNull;
22 import android.annotation.SystemApi;
23 
24 import java.lang.annotation.Retention;
25 import java.lang.annotation.RetentionPolicy;
26 
27 /**
28  * OffloadEngine is an interface for mDns hardware offloading.
29  *
30  * An offloading engine can interact with the firmware code to instruct the hardware to
31  * offload some of mDns network traffic before it reached android OS. This can improve the
32  * power consumption performance of the host system by not always waking up the OS to handle
33  * the mDns packet when the device is in low power mode.
34  *
35  * @hide
36  */
37 @FlaggedApi("com.android.net.flags.register_nsd_offload_engine_api")
38 @SystemApi
39 public interface OffloadEngine {
40     /**
41      * Indicates that the OffloadEngine can generate replies to mDns queries.
42      *
43      * @see OffloadServiceInfo#getOffloadPayload()
44      */
45     int OFFLOAD_TYPE_REPLY = 1;
46     /**
47      * Indicates that the OffloadEngine can filter and drop mDns queries.
48      */
49     int OFFLOAD_TYPE_FILTER_QUERIES = 1 << 1;
50     /**
51      * Indicates that the OffloadEngine can filter and drop mDns replies. It can allow mDns packets
52      * to be received even when no app holds a {@link android.net.wifi.WifiManager.MulticastLock}.
53      */
54     int OFFLOAD_TYPE_FILTER_REPLIES = 1 << 2;
55 
56     /**
57      * Indicates that the OffloadEngine can bypass multicast lock.
58      */
59     int OFFLOAD_CAPABILITY_BYPASS_MULTICAST_LOCK = 1;
60 
61     /**
62      * @hide
63      */
64     @Retention(RetentionPolicy.SOURCE)
65     @LongDef(flag = true, prefix = {"OFFLOAD_TYPE"}, value = {
66             OFFLOAD_TYPE_REPLY,
67             OFFLOAD_TYPE_FILTER_QUERIES,
68             OFFLOAD_TYPE_FILTER_REPLIES,
69     })
70     @interface OffloadType {}
71 
72     /**
73      * @hide
74      */
75     @Retention(RetentionPolicy.SOURCE)
76     @LongDef(flag = true, prefix = {"OFFLOAD_CAPABILITY"}, value = {
77             OFFLOAD_CAPABILITY_BYPASS_MULTICAST_LOCK
78     })
79     @interface OffloadCapability {}
80 
81     /**
82      * To be called when the OffloadServiceInfo is added or updated.
83      *
84      * @param info The OffloadServiceInfo to add or update.
85      */
onOffloadServiceUpdated(@onNull OffloadServiceInfo info)86     void onOffloadServiceUpdated(@NonNull OffloadServiceInfo info);
87 
88     /**
89      * To be called when the OffloadServiceInfo is removed.
90      *
91      * @param info The OffloadServiceInfo to remove.
92      */
onOffloadServiceRemoved(@onNull OffloadServiceInfo info)93     void onOffloadServiceRemoved(@NonNull OffloadServiceInfo info);
94 }
95