1 /* 2 * Copyright (C) 2015 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.statementservice; 18 19 import android.app.Service; 20 import android.content.Intent; 21 import android.net.http.HttpResponseCache; 22 import android.os.Bundle; 23 import android.os.Handler; 24 import android.os.HandlerThread; 25 import android.os.IBinder; 26 import android.os.Looper; 27 import android.os.ResultReceiver; 28 import android.util.Log; 29 30 import com.android.statementservice.retriever.AbstractAsset; 31 import com.android.statementservice.retriever.AbstractAssetMatcher; 32 import com.android.statementservice.retriever.AbstractStatementRetriever; 33 import com.android.statementservice.retriever.AbstractStatementRetriever.Result; 34 import com.android.statementservice.retriever.AssociationServiceException; 35 import com.android.statementservice.retriever.Relation; 36 import com.android.statementservice.retriever.Statement; 37 38 import org.json.JSONException; 39 40 import java.io.File; 41 import java.io.IOException; 42 import java.util.ArrayList; 43 import java.util.List; 44 import java.util.concurrent.Callable; 45 46 /** 47 * Handles com.android.statementservice.service.CHECK_ALL_ACTION intents. 48 */ 49 public final class DirectStatementService extends Service { 50 private static final String TAG = DirectStatementService.class.getSimpleName(); 51 52 /** 53 * Returns true if every asset in {@code SOURCE_ASSET_DESCRIPTORS} is associated with {@code 54 * EXTRA_TARGET_ASSET_DESCRIPTOR} for {@code EXTRA_RELATION} relation. 55 * 56 * <p>Takes parameter {@code EXTRA_RELATION}, {@code SOURCE_ASSET_DESCRIPTORS}, {@code 57 * EXTRA_TARGET_ASSET_DESCRIPTOR}, and {@code EXTRA_RESULT_RECEIVER}. 58 */ 59 public static final String CHECK_ALL_ACTION = 60 "com.android.statementservice.service.CHECK_ALL_ACTION"; 61 62 /** 63 * Parameter for {@link #CHECK_ALL_ACTION}. 64 * 65 * <p>A relation string. 66 */ 67 public static final String EXTRA_RELATION = 68 "com.android.statementservice.service.RELATION"; 69 70 /** 71 * Parameter for {@link #CHECK_ALL_ACTION}. 72 * 73 * <p>An array of asset descriptors in JSON. 74 */ 75 public static final String EXTRA_SOURCE_ASSET_DESCRIPTORS = 76 "com.android.statementservice.service.SOURCE_ASSET_DESCRIPTORS"; 77 78 /** 79 * Parameter for {@link #CHECK_ALL_ACTION}. 80 * 81 * <p>An asset descriptor in JSON. 82 */ 83 public static final String EXTRA_TARGET_ASSET_DESCRIPTOR = 84 "com.android.statementservice.service.TARGET_ASSET_DESCRIPTOR"; 85 86 /** 87 * Parameter for {@link #CHECK_ALL_ACTION}. 88 * 89 * <p>A {@code ResultReceiver} instance that will be used to return the result. If the request 90 * failed, return {@link #RESULT_FAIL} and an empty {@link android.os.Bundle}. Otherwise, return 91 * {@link #RESULT_SUCCESS} and a {@link android.os.Bundle} with the result stored in {@link 92 * #IS_ASSOCIATED}. 93 */ 94 public static final String EXTRA_RESULT_RECEIVER = 95 "com.android.statementservice.service.RESULT_RECEIVER"; 96 97 /** 98 * A boolean bundle entry that stores the result of {@link #CHECK_ALL_ACTION}. 99 * This is set only if the service returns with {@code RESULT_SUCCESS}. 100 * {@code IS_ASSOCIATED} is true if and only if {@code FAILED_SOURCES} is empty. 101 */ 102 public static final String IS_ASSOCIATED = "is_associated"; 103 104 /** 105 * A String ArrayList bundle entry that stores sources that can't be verified. 106 */ 107 public static final String FAILED_SOURCES = "failed_sources"; 108 109 /** 110 * Returned by the service if the request is successfully processed. The caller should check 111 * the {@code IS_ASSOCIATED} field to determine if the association exists or not. 112 */ 113 public static final int RESULT_SUCCESS = 0; 114 115 /** 116 * Returned by the service if the request failed. The request will fail if, for example, the 117 * input is not well formed, or the network is not available. 118 */ 119 public static final int RESULT_FAIL = 1; 120 121 private static final long HTTP_CACHE_SIZE_IN_BYTES = 1 * 1024 * 1024; // 1 MBytes 122 private static final String CACHE_FILENAME = "request_cache"; 123 124 private AbstractStatementRetriever mStatementRetriever; 125 private Handler mHandler; 126 private HandlerThread mThread; 127 private HttpResponseCache mHttpResponseCache; 128 129 @Override 130 public void onCreate() { 131 mThread = new HandlerThread("DirectStatementService thread", 132 android.os.Process.THREAD_PRIORITY_BACKGROUND); 133 mThread.start(); 134 onCreate(AbstractStatementRetriever.createDirectRetriever(this), mThread.getLooper(), 135 getCacheDir()); 136 } 137 138 /** 139 * Creates a DirectStatementService with the dependencies passed in for easy testing. 140 */ 141 public void onCreate(AbstractStatementRetriever statementRetriever, Looper looper, 142 File cacheDir) { 143 super.onCreate(); 144 mStatementRetriever = statementRetriever; 145 mHandler = new Handler(looper); 146 147 try { 148 File httpCacheDir = new File(cacheDir, CACHE_FILENAME); 149 mHttpResponseCache = HttpResponseCache.install(httpCacheDir, HTTP_CACHE_SIZE_IN_BYTES); 150 } catch (IOException e) { 151 Log.i(TAG, "HTTPS response cache installation failed:" + e); 152 } 153 } 154 155 @Override 156 public void onDestroy() { 157 super.onDestroy(); 158 if (mThread != null) { 159 mThread.quit(); 160 } 161 162 try { 163 if (mHttpResponseCache != null) { 164 mHttpResponseCache.delete(); 165 } 166 } catch (IOException e) { 167 Log.i(TAG, "HTTP(S) response cache deletion failed:" + e); 168 } 169 } 170 171 @Override 172 public IBinder onBind(Intent intent) { 173 return null; 174 } 175 176 @Override 177 public int onStartCommand(Intent intent, int flags, int startId) { 178 super.onStartCommand(intent, flags, startId); 179 180 if (intent == null) { 181 Log.e(TAG, "onStartCommand called with null intent"); 182 return START_STICKY; 183 } 184 185 if (intent.getAction().equals(CHECK_ALL_ACTION)) { 186 187 Bundle extras = intent.getExtras(); 188 List<String> sources = extras.getStringArrayList(EXTRA_SOURCE_ASSET_DESCRIPTORS); 189 String target = extras.getString(EXTRA_TARGET_ASSET_DESCRIPTOR); 190 String relation = extras.getString(EXTRA_RELATION); 191 ResultReceiver resultReceiver = extras.getParcelable(EXTRA_RESULT_RECEIVER); 192 193 if (resultReceiver == null) { 194 Log.e(TAG, " Intent does not have extra " + EXTRA_RESULT_RECEIVER); 195 return START_STICKY; 196 } 197 if (sources == null) { 198 Log.e(TAG, " Intent does not have extra " + EXTRA_SOURCE_ASSET_DESCRIPTORS); 199 resultReceiver.send(RESULT_FAIL, Bundle.EMPTY); 200 return START_STICKY; 201 } 202 if (target == null) { 203 Log.e(TAG, " Intent does not have extra " + EXTRA_TARGET_ASSET_DESCRIPTOR); 204 resultReceiver.send(RESULT_FAIL, Bundle.EMPTY); 205 return START_STICKY; 206 } 207 if (relation == null) { 208 Log.e(TAG, " Intent does not have extra " + EXTRA_RELATION); 209 resultReceiver.send(RESULT_FAIL, Bundle.EMPTY); 210 return START_STICKY; 211 } 212 213 mHandler.post(new ExceptionLoggingFutureTask<Void>( 214 new IsAssociatedCallable(sources, target, relation, resultReceiver), TAG)); 215 } else { 216 Log.e(TAG, "onStartCommand called with unsupported action: " + intent.getAction()); 217 } 218 return START_STICKY; 219 } 220 221 private class IsAssociatedCallable implements Callable<Void> { 222 223 private List<String> mSources; 224 private String mTarget; 225 private String mRelation; 226 private ResultReceiver mResultReceiver; 227 228 public IsAssociatedCallable(List<String> sources, String target, String relation, 229 ResultReceiver resultReceiver) { 230 mSources = sources; 231 mTarget = target; 232 mRelation = relation; 233 mResultReceiver = resultReceiver; 234 } 235 236 private boolean verifyOneSource(AbstractAsset source, AbstractAssetMatcher target, 237 Relation relation) throws AssociationServiceException { 238 Result statements = mStatementRetriever.retrieveStatements(source); 239 for (Statement statement : statements.getStatements()) { 240 if (relation.matches(statement.getRelation()) 241 && target.matches(statement.getTarget())) { 242 return true; 243 } 244 } 245 return false; 246 } 247 248 @Override 249 public Void call() { 250 Bundle result = new Bundle(); 251 ArrayList<String> failedSources = new ArrayList<String>(); 252 AbstractAssetMatcher target; 253 Relation relation; 254 try { 255 target = AbstractAssetMatcher.createMatcher(mTarget); 256 relation = Relation.create(mRelation); 257 } catch (AssociationServiceException | JSONException e) { 258 Log.e(TAG, "isAssociatedCallable failed with exception", e); 259 mResultReceiver.send(RESULT_FAIL, Bundle.EMPTY); 260 return null; 261 } 262 263 boolean allSourcesVerified = true; 264 for (String sourceString : mSources) { 265 AbstractAsset source; 266 try { 267 source = AbstractAsset.create(sourceString); 268 } catch (AssociationServiceException e) { 269 mResultReceiver.send(RESULT_FAIL, Bundle.EMPTY); 270 return null; 271 } 272 273 try { 274 if (!verifyOneSource(source, target, relation)) { 275 failedSources.add(source.toJson()); 276 allSourcesVerified = false; 277 } 278 } catch (AssociationServiceException e) { 279 failedSources.add(source.toJson()); 280 allSourcesVerified = false; 281 } 282 } 283 284 result.putBoolean(IS_ASSOCIATED, allSourcesVerified); 285 result.putStringArrayList(FAILED_SOURCES, failedSources); 286 mResultReceiver.send(RESULT_SUCCESS, result); 287 return null; 288 } 289 } 290 } 291
