1 /*
2  * Copyright (C) 2021 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 package com.android.server.wifi;
17 
18 import android.annotation.NonNull;
19 import android.annotation.Nullable;
20 import android.util.Log;
21 
22 import com.android.server.wifi.util.WifiConfigStoreEncryptionUtil;
23 import com.android.server.wifi.util.XmlUtil;
24 
25 import org.xmlpull.v1.XmlPullParser;
26 import org.xmlpull.v1.XmlPullParserException;
27 import org.xmlpull.v1.XmlSerializer;
28 
29 import java.io.IOException;
30 import java.util.Collections;
31 import java.util.HashMap;
32 import java.util.Map;
33 /**
34  * This class performs serialization and parsing of XML data block that contain the map of IMSI
35  * protection exemption user approval info.
36  */
37 public class ImsiPrivacyProtectionExemptionStoreData implements WifiConfigStore.StoreData {
38     private static final String TAG = "ImsiPrivacyProtectionExemptionStoreData";
39     private static final String XML_TAG_SECTION_HEADER_IMSI_PROTECTION_EXEMPTION_CARRIER_MAP =
40             "ImsiPrivacyProtectionExemptionMap";
41     private static final String XML_TAG_CARRIER_EXEMPTION_MAP = "CarrierExemptionMap";
42     /**
43      * Interface define the data source for the carrier IMSI protection exemption map store data.
44      */
45     public interface DataSource {
46         /**
47          * Retrieve the IMSI protection exemption map from the data source to serialize to disk.
48          *
49          * @return Map of carrier Id to if allowed.
50          */
toSerialize()51         Map<Integer, Boolean> toSerialize();
52         /**
53          * Set the IMSI protection exemption map in the data source after serializing them from disk
54          *
55          * @param imsiProtectionExemptionMap Map of carrier Id to allowed or not.
56          */
fromDeserialized(Map<Integer, Boolean> imsiProtectionExemptionMap)57         void fromDeserialized(Map<Integer, Boolean> imsiProtectionExemptionMap);
58         /**
59          * Clear internal data structure in preparation for user switch or initial store read.
60          */
reset()61         void reset();
62         /**
63          * Indicates whether there is new data to serialize.
64          */
hasNewDataToSerialize()65         boolean hasNewDataToSerialize();
66     }
67     private final DataSource mDataSource;
68     /**
69      * Set the data source fot store data.
70      */
ImsiPrivacyProtectionExemptionStoreData(@onNull DataSource dataSource)71     public ImsiPrivacyProtectionExemptionStoreData(@NonNull DataSource dataSource) {
72         mDataSource = dataSource;
73     }
74     @Override
serializeData(XmlSerializer out, WifiConfigStoreEncryptionUtil encryptionUtil)75     public void serializeData(XmlSerializer out, WifiConfigStoreEncryptionUtil encryptionUtil)
76             throws XmlPullParserException, IOException {
77         Map<String, Boolean> dataToSerialize = integerMapToStringMap(mDataSource.toSerialize());
78         XmlUtil.writeNextValue(out, XML_TAG_CARRIER_EXEMPTION_MAP, dataToSerialize);
79     }
80     @Override
deserializeData(XmlPullParser in, int outerTagDepth, int version, WifiConfigStoreEncryptionUtil encryptionUtil)81     public void deserializeData(XmlPullParser in, int outerTagDepth, int version,
82             WifiConfigStoreEncryptionUtil encryptionUtil)
83             throws XmlPullParserException, IOException {
84         // Ignore empty reads.
85         if (in == null) {
86             mDataSource.fromDeserialized(Collections.emptyMap());
87             return;
88         }
89         mDataSource.fromDeserialized(parseCarrierImsiProtectionExemptionMap(in, outerTagDepth,
90                 version, encryptionUtil));
91     }
parseCarrierImsiProtectionExemptionMap(XmlPullParser in, int outerTagDepth, @WifiConfigStore.Version int version, @Nullable WifiConfigStoreEncryptionUtil encryptionUtil)92     private Map<Integer, Boolean> parseCarrierImsiProtectionExemptionMap(XmlPullParser in,
93             int outerTagDepth,
94             @WifiConfigStore.Version int version,
95             @Nullable WifiConfigStoreEncryptionUtil encryptionUtil)
96             throws XmlPullParserException, IOException {
97         Map<String, Boolean> protectionExemptionMap = new HashMap<>();
98         while (!XmlUtil.isNextSectionEnd(in, outerTagDepth)) {
99             String[] valueName = new String[1];
100             Object value = XmlUtil.readCurrentValue(in, valueName);
101             if (valueName[0] == null) {
102                 throw new XmlPullParserException("Missing value name");
103             }
104             switch (valueName[0]) {
105                 case XML_TAG_CARRIER_EXEMPTION_MAP:
106                     if (value instanceof Map) {
107                         protectionExemptionMap = (Map<String, Boolean>) value;
108                     }
109                     break;
110                 default:
111                     Log.w(TAG, "Unknown tag under "
112                             + XML_TAG_SECTION_HEADER_IMSI_PROTECTION_EXEMPTION_CARRIER_MAP
113                             + ": " + valueName[0]);
114                     break;
115             }
116         }
117         return stringMapToIntegerMap(protectionExemptionMap);
118     }
integerMapToStringMap(Map<Integer, Boolean> input)119     private Map<String, Boolean> integerMapToStringMap(Map<Integer, Boolean> input) {
120         Map<String, Boolean> output = new HashMap<>();
121         if (input == null) {
122             return output;
123         }
124         for (Map.Entry<Integer, Boolean> entry : input.entrySet()) {
125             output.put(Integer.toString(entry.getKey()), entry.getValue());
126         }
127         return output;
128     }
stringMapToIntegerMap(Map<String, Boolean> input)129     private Map<Integer, Boolean> stringMapToIntegerMap(Map<String, Boolean> input) {
130         Map<Integer, Boolean> output = new HashMap<>();
131         if (input == null) {
132             return output;
133         }
134         for (Map.Entry<String, Boolean> entry : input.entrySet()) {
135             try {
136                 output.put(Integer.valueOf(entry.getKey()), entry.getValue());
137             } catch (NumberFormatException e) {
138                 Log.e(TAG, "Failed to Integer convert: " + entry.getKey());
139             }
140         }
141         return output;
142     }
143     @Override
resetData()144     public void resetData() {
145         mDataSource.reset();
146     }
147     @Override
hasNewDataToSerialize()148     public boolean hasNewDataToSerialize() {
149         return mDataSource.hasNewDataToSerialize();
150     }
151     @Override
getName()152     public String getName() {
153         return XML_TAG_SECTION_HEADER_IMSI_PROTECTION_EXEMPTION_CARRIER_MAP;
154     }
155     @Override
getStoreFileId()156     public int getStoreFileId() {
157         // User general store.
158         return WifiConfigStore.STORE_FILE_USER_GENERAL;
159     }
160 }
161