1 /*
2  * Copyright (C) 2017 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 com.android.server.wifi.hotspot2.anqp;
18 
19 import android.net.wifi.WifiSsid;
20 
21 import com.android.internal.annotations.VisibleForTesting;
22 
23 import java.net.ProtocolException;
24 import java.nio.BufferUnderflowException;
25 import java.nio.ByteBuffer;
26 import java.util.ArrayList;
27 import java.util.Collections;
28 import java.util.List;
29 import java.util.Objects;
30 
31 /**
32  * The OSU Providers List vendor specific ANQP Element,
33  * Wi-Fi Alliance Hotspot 2.0 (Release 2) Technical Specification - Version 5.00,
34  * section 4.8.
35  *
36  * Format:
37  *
38  * | OSU SSID Length | OSU SSID | Number of OSU Providers | Provider #1 | ...
39  *          1          variable             1                 variable
40  *
41  */
42 public class HSOsuProvidersElement extends ANQPElement {
43     /**
44      * Maximum length for a SSID.  Refer to IEEE 802.11-2012 Section 8.4.2.2
45      * for more info.
46      */
47     @VisibleForTesting
48     public static final int MAXIMUM_OSU_SSID_LENGTH = 32;
49 
50     private final WifiSsid mOsuSsid;
51     private final List<OsuProviderInfo> mProviders;
52 
53     @VisibleForTesting
HSOsuProvidersElement(WifiSsid osuSsid, List<OsuProviderInfo> providers)54     public HSOsuProvidersElement(WifiSsid osuSsid, List<OsuProviderInfo> providers) {
55         super(Constants.ANQPElementType.HSOSUProviders);
56         mOsuSsid = osuSsid;
57         mProviders = providers;
58     }
59 
60     /**
61      * Parse a HSOsuProvidersElement from the given buffer.
62      *
63      * @param payload The buffer to read from
64      * @return {@link HSOsuProvidersElement}
65      * @throws BufferUnderflowException
66      * @throws ProtocolException
67      */
parse(ByteBuffer payload)68     public static HSOsuProvidersElement parse(ByteBuffer payload)
69             throws ProtocolException {
70         int ssidLength = payload.get() & 0xFF;
71         if (ssidLength > MAXIMUM_OSU_SSID_LENGTH) {
72             throw new ProtocolException("Invalid SSID length: " + ssidLength);
73         }
74         byte[] ssidBytes = new byte[ssidLength];
75         payload.get(ssidBytes);
76 
77         int numProviders = payload.get() & 0xFF;
78         List<OsuProviderInfo> providers = new ArrayList<>();
79         while (numProviders > 0) {
80             providers.add(OsuProviderInfo.parse(payload));
81             numProviders--;
82         }
83 
84         return new HSOsuProvidersElement(WifiSsid.createFromByteArray(ssidBytes), providers);
85     }
86 
getOsuSsid()87     public WifiSsid getOsuSsid() {
88         return mOsuSsid;
89     }
90 
getProviders()91     public List<OsuProviderInfo> getProviders() {
92         return Collections.unmodifiableList(mProviders);
93     }
94 
95     @Override
equals(Object thatObject)96     public boolean equals(Object thatObject) {
97         if (this == thatObject) {
98             return true;
99         }
100         if (!(thatObject instanceof HSOsuProvidersElement)) {
101             return false;
102         }
103         HSOsuProvidersElement that = (HSOsuProvidersElement) thatObject;
104         return (mOsuSsid == null ? that.mOsuSsid == null : mOsuSsid.equals(that.mOsuSsid))
105                 && (mProviders == null ? that.mProviders == null
106                         : mProviders.equals(that.mProviders));
107     }
108 
109     @Override
hashCode()110     public int hashCode() {
111         return Objects.hash(mOsuSsid, mProviders);
112     }
113 
114     @Override
toString()115     public String toString() {
116         return "OSUProviders{" + "mOsuSsid=" + mOsuSsid + ", mProviders=" + mProviders + "}";
117     }
118 }
119