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