NetworkMonitor.java revision cd29cb66f92b008e8547f70b30223ce8dbc1fb86
1/* 2 * Copyright (C) 2014 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 17package com.android.server.connectivity; 18 19import android.app.AlarmManager; 20import android.app.PendingIntent; 21import android.content.BroadcastReceiver; 22import android.content.ComponentName; 23import android.content.Context; 24import android.content.Intent; 25import android.content.IntentFilter; 26import android.net.ConnectivityManager; 27import android.net.Network; 28import android.net.NetworkCapabilities; 29import android.net.NetworkInfo; 30import android.net.NetworkRequest; 31import android.net.TrafficStats; 32import android.net.Uri; 33import android.net.wifi.WifiInfo; 34import android.net.wifi.WifiManager; 35import android.os.Handler; 36import android.os.Message; 37import android.os.SystemClock; 38import android.os.SystemProperties; 39import android.os.UserHandle; 40import android.provider.Settings; 41import android.telephony.CellIdentityCdma; 42import android.telephony.CellIdentityGsm; 43import android.telephony.CellIdentityLte; 44import android.telephony.CellIdentityWcdma; 45import android.telephony.CellInfo; 46import android.telephony.CellInfoCdma; 47import android.telephony.CellInfoGsm; 48import android.telephony.CellInfoLte; 49import android.telephony.CellInfoWcdma; 50import android.telephony.TelephonyManager; 51import android.util.Log; 52 53import com.android.internal.util.Protocol; 54import com.android.internal.util.State; 55import com.android.internal.util.StateMachine; 56import com.android.server.ConnectivityService; 57import com.android.server.connectivity.NetworkAgentInfo; 58 59import java.io.IOException; 60import java.net.HttpURLConnection; 61import java.net.URL; 62import java.util.List; 63import java.util.Random; 64 65/** 66 * {@hide} 67 */ 68public class NetworkMonitor extends StateMachine { 69 private static final boolean DBG = true; 70 private static final String TAG = "NetworkMonitor"; 71 private static final String DEFAULT_SERVER = "connectivitycheck.android.com"; 72 private static final int SOCKET_TIMEOUT_MS = 10000; 73 public static final String ACTION_NETWORK_CONDITIONS_MEASURED = 74 "android.net.conn.NETWORK_CONDITIONS_MEASURED"; 75 public static final String EXTRA_CONNECTIVITY_TYPE = "extra_connectivity_type"; 76 public static final String EXTRA_NETWORK_TYPE = "extra_network_type"; 77 public static final String EXTRA_RESPONSE_RECEIVED = "extra_response_received"; 78 public static final String EXTRA_IS_CAPTIVE_PORTAL = "extra_is_captive_portal"; 79 public static final String EXTRA_CELL_ID = "extra_cellid"; 80 public static final String EXTRA_SSID = "extra_ssid"; 81 public static final String EXTRA_BSSID = "extra_bssid"; 82 /** real time since boot */ 83 public static final String EXTRA_REQUEST_TIMESTAMP_MS = "extra_request_timestamp_ms"; 84 public static final String EXTRA_RESPONSE_TIMESTAMP_MS = "extra_response_timestamp_ms"; 85 86 private static final String PERMISSION_ACCESS_NETWORK_CONDITIONS = 87 "android.permission.ACCESS_NETWORK_CONDITIONS"; 88 89 // Keep these in sync with CaptivePortalLoginActivity.java. 90 // Intent broadcast from CaptivePortalLogin indicating sign-in is complete. 91 // Extras: 92 // EXTRA_TEXT = netId 93 // LOGGED_IN_RESULT = one of the CAPTIVE_PORTAL_APP_RETURN_* values below. 94 // RESPONSE_TOKEN = data fragment from launching Intent 95 private static final String ACTION_CAPTIVE_PORTAL_LOGGED_IN = 96 "android.net.netmon.captive_portal_logged_in"; 97 private static final String LOGGED_IN_RESULT = "result"; 98 private static final String RESPONSE_TOKEN = "response_token"; 99 100 // After a network has been tested this result can be sent with EVENT_NETWORK_TESTED. 101 // The network should be used as a default internet connection. It was found to be: 102 // 1. a functioning network providing internet access, or 103 // 2. a captive portal and the user decided to use it as is. 104 public static final int NETWORK_TEST_RESULT_VALID = 0; 105 // After a network has been tested this result can be sent with EVENT_NETWORK_TESTED. 106 // The network should not be used as a default internet connection. It was found to be: 107 // 1. a captive portal and the user is prompted to sign-in, or 108 // 2. a captive portal and the user did not want to use it, or 109 // 3. a broken network (e.g. DNS failed, connect failed, HTTP request failed). 110 public static final int NETWORK_TEST_RESULT_INVALID = 1; 111 112 private static final int BASE = Protocol.BASE_NETWORK_MONITOR; 113 114 /** 115 * Inform NetworkMonitor that their network is connected. 116 * Initiates Network Validation. 117 */ 118 public static final int CMD_NETWORK_CONNECTED = BASE + 1; 119 120 /** 121 * Inform ConnectivityService that the network has been tested. 122 * obj = NetworkAgentInfo 123 * arg1 = One of the NETWORK_TESTED_RESULT_* constants. 124 */ 125 public static final int EVENT_NETWORK_TESTED = BASE + 2; 126 127 /** 128 * Inform NetworkMonitor to linger a network. The Monitor should 129 * start a timer and/or start watching for zero live connections while 130 * moving towards LINGER_COMPLETE. After the Linger period expires 131 * (or other events mark the end of the linger state) the LINGER_COMPLETE 132 * event should be sent and the network will be shut down. If a 133 * CMD_NETWORK_CONNECTED happens before the LINGER completes 134 * it indicates further desire to keep the network alive and so 135 * the LINGER is aborted. 136 */ 137 public static final int CMD_NETWORK_LINGER = BASE + 3; 138 139 /** 140 * Message to self indicating linger delay has expired. 141 * arg1 = Token to ignore old messages. 142 */ 143 private static final int CMD_LINGER_EXPIRED = BASE + 4; 144 145 /** 146 * Inform ConnectivityService that the network LINGER period has 147 * expired. 148 * obj = NetworkAgentInfo 149 */ 150 public static final int EVENT_NETWORK_LINGER_COMPLETE = BASE + 5; 151 152 /** 153 * Message to self indicating it's time to evaluate a network's connectivity. 154 * arg1 = Token to ignore old messages. 155 */ 156 private static final int CMD_REEVALUATE = BASE + 6; 157 158 /** 159 * Inform NetworkMonitor that the network has disconnected. 160 */ 161 public static final int CMD_NETWORK_DISCONNECTED = BASE + 7; 162 163 /** 164 * Force evaluation even if it has succeeded in the past. 165 * arg1 = UID responsible for requesting this reeval. Will be billed for data. 166 */ 167 public static final int CMD_FORCE_REEVALUATION = BASE + 8; 168 169 /** 170 * Message to self indicating captive portal app finished. 171 * arg1 = one of: CAPTIVE_PORTAL_APP_RETURN_APPEASED, 172 * CAPTIVE_PORTAL_APP_RETURN_UNWANTED, 173 * CAPTIVE_PORTAL_APP_RETURN_WANTED_AS_IS 174 */ 175 private static final int CMD_CAPTIVE_PORTAL_APP_FINISHED = BASE + 9; 176 177 /** 178 * Request ConnectivityService display provisioning notification. 179 * arg1 = Whether to make the notification visible. 180 * arg2 = NetID. 181 * obj = Intent to be launched when notification selected by user, null if !arg1. 182 */ 183 public static final int EVENT_PROVISIONING_NOTIFICATION = BASE + 10; 184 185 /** 186 * Message to self indicating sign-in app bypassed captive portal. 187 */ 188 private static final int EVENT_APP_BYPASSED_CAPTIVE_PORTAL = BASE + 11; 189 190 /** 191 * Message to self indicating no sign-in app responded. 192 */ 193 private static final int EVENT_NO_APP_RESPONSE = BASE + 12; 194 195 /** 196 * Message to self indicating sign-in app indicates sign-in is not possible. 197 */ 198 private static final int EVENT_APP_INDICATES_SIGN_IN_IMPOSSIBLE = BASE + 13; 199 200 /** 201 * Return codes from captive portal sign-in app. 202 */ 203 public static final int CAPTIVE_PORTAL_APP_RETURN_APPEASED = 0; 204 public static final int CAPTIVE_PORTAL_APP_RETURN_UNWANTED = 1; 205 public static final int CAPTIVE_PORTAL_APP_RETURN_WANTED_AS_IS = 2; 206 207 private static final String LINGER_DELAY_PROPERTY = "persist.netmon.linger"; 208 // Default to 30s linger time-out. 209 private static final int DEFAULT_LINGER_DELAY_MS = 30000; 210 private final int mLingerDelayMs; 211 private int mLingerToken = 0; 212 213 // Negative values disable reevaluation. 214 private static final String REEVALUATE_DELAY_PROPERTY = "persist.netmon.reeval_delay"; 215 // Default to 5s reevaluation delay. 216 private static final int DEFAULT_REEVALUATE_DELAY_MS = 5000; 217 private static final int MAX_RETRIES = 10; 218 // Between groups of MAX_RETRIES evaluation attempts, pause 10 mins in hopes ISP outage passes. 219 private static final int REEVALUATE_PAUSE_MS = 10*60*1000; 220 private final int mReevaluateDelayMs; 221 private int mReevaluateToken = 0; 222 private static final int INVALID_UID = -1; 223 private int mUidResponsibleForReeval = INVALID_UID; 224 225 private final Context mContext; 226 private final Handler mConnectivityServiceHandler; 227 private final NetworkAgentInfo mNetworkAgentInfo; 228 private final TelephonyManager mTelephonyManager; 229 private final WifiManager mWifiManager; 230 private final AlarmManager mAlarmManager; 231 private final NetworkRequest mDefaultRequest; 232 233 private String mServer; 234 private boolean mIsCaptivePortalCheckEnabled = false; 235 236 // Set if the user explicitly selected "Do not use this network" in captive portal sign-in app. 237 private boolean mUserDoesNotWant = false; 238 239 public boolean systemReady = false; 240 241 private final State mDefaultState = new DefaultState(); 242 private final State mOfflineState = new OfflineState(); 243 private final State mValidatedState = new ValidatedState(); 244 private final State mMaybeNotifyState = new MaybeNotifyState(); 245 private final State mEvaluatingState = new EvaluatingState(); 246 private final State mCaptivePortalState = new CaptivePortalState(); 247 private final State mLingeringState = new LingeringState(); 248 249 private CaptivePortalLoggedInBroadcastReceiver mCaptivePortalLoggedInBroadcastReceiver = null; 250 private String mCaptivePortalLoggedInResponseToken = null; 251 252 public NetworkMonitor(Context context, Handler handler, NetworkAgentInfo networkAgentInfo, 253 NetworkRequest defaultRequest) { 254 // Add suffix indicating which NetworkMonitor we're talking about. 255 super(TAG + networkAgentInfo.name()); 256 257 mContext = context; 258 mConnectivityServiceHandler = handler; 259 mNetworkAgentInfo = networkAgentInfo; 260 mTelephonyManager = (TelephonyManager) context.getSystemService(Context.TELEPHONY_SERVICE); 261 mWifiManager = (WifiManager) context.getSystemService(Context.WIFI_SERVICE); 262 mAlarmManager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE); 263 mDefaultRequest = defaultRequest; 264 265 addState(mDefaultState); 266 addState(mOfflineState, mDefaultState); 267 addState(mValidatedState, mDefaultState); 268 addState(mMaybeNotifyState, mDefaultState); 269 addState(mEvaluatingState, mMaybeNotifyState); 270 addState(mCaptivePortalState, mMaybeNotifyState); 271 addState(mLingeringState, mDefaultState); 272 setInitialState(mDefaultState); 273 274 mServer = Settings.Global.getString(mContext.getContentResolver(), 275 Settings.Global.CAPTIVE_PORTAL_SERVER); 276 if (mServer == null) mServer = DEFAULT_SERVER; 277 278 mLingerDelayMs = SystemProperties.getInt(LINGER_DELAY_PROPERTY, DEFAULT_LINGER_DELAY_MS); 279 mReevaluateDelayMs = SystemProperties.getInt(REEVALUATE_DELAY_PROPERTY, 280 DEFAULT_REEVALUATE_DELAY_MS); 281 282 mIsCaptivePortalCheckEnabled = Settings.Global.getInt(mContext.getContentResolver(), 283 Settings.Global.CAPTIVE_PORTAL_DETECTION_ENABLED, 1) == 1; 284 285 mCaptivePortalLoggedInResponseToken = String.valueOf(new Random().nextLong()); 286 287 start(); 288 } 289 290 @Override 291 protected void log(String s) { 292 Log.d(TAG + "/" + mNetworkAgentInfo.name(), s); 293 } 294 295 // DefaultState is the parent of all States. It exists only to handle CMD_* messages but 296 // does not entail any real state (hence no enter() or exit() routines). 297 private class DefaultState extends State { 298 @Override 299 public boolean processMessage(Message message) { 300 if (DBG) log(getName() + message.toString()); 301 switch (message.what) { 302 case CMD_NETWORK_LINGER: 303 if (DBG) log("Lingering"); 304 transitionTo(mLingeringState); 305 return HANDLED; 306 case CMD_NETWORK_CONNECTED: 307 if (DBG) log("Connected"); 308 transitionTo(mEvaluatingState); 309 return HANDLED; 310 case CMD_NETWORK_DISCONNECTED: 311 if (DBG) log("Disconnected - quitting"); 312 if (mCaptivePortalLoggedInBroadcastReceiver != null) { 313 mContext.unregisterReceiver(mCaptivePortalLoggedInBroadcastReceiver); 314 mCaptivePortalLoggedInBroadcastReceiver = null; 315 } 316 quit(); 317 return HANDLED; 318 case CMD_FORCE_REEVALUATION: 319 if (DBG) log("Forcing reevaluation"); 320 mUidResponsibleForReeval = message.arg1; 321 transitionTo(mEvaluatingState); 322 return HANDLED; 323 case CMD_CAPTIVE_PORTAL_APP_FINISHED: 324 // Previous token was broadcast, come up with a new one. 325 mCaptivePortalLoggedInResponseToken = String.valueOf(new Random().nextLong()); 326 switch (message.arg1) { 327 case CAPTIVE_PORTAL_APP_RETURN_APPEASED: 328 case CAPTIVE_PORTAL_APP_RETURN_WANTED_AS_IS: 329 transitionTo(mValidatedState); 330 break; 331 case CAPTIVE_PORTAL_APP_RETURN_UNWANTED: 332 mUserDoesNotWant = true; 333 // TODO: Should teardown network. 334 transitionTo(mOfflineState); 335 break; 336 } 337 return HANDLED; 338 default: 339 return HANDLED; 340 } 341 } 342 } 343 344 // Being in the OfflineState State indicates a Network is unwanted or failed validation. 345 private class OfflineState extends State { 346 @Override 347 public void enter() { 348 mConnectivityServiceHandler.sendMessage(obtainMessage(EVENT_NETWORK_TESTED, 349 NETWORK_TEST_RESULT_INVALID, 0, mNetworkAgentInfo)); 350 if (!mUserDoesNotWant) sendMessageDelayed(CMD_FORCE_REEVALUATION, REEVALUATE_PAUSE_MS); 351 } 352 353 @Override 354 public boolean processMessage(Message message) { 355 if (DBG) log(getName() + message.toString()); 356 switch (message.what) { 357 case CMD_FORCE_REEVALUATION: 358 // If the user has indicated they explicitly do not want to use this network, 359 // don't allow a reevaluation as this will be pointless and could result in 360 // the user being annoyed with repeated unwanted notifications. 361 return mUserDoesNotWant ? HANDLED : NOT_HANDLED; 362 default: 363 return NOT_HANDLED; 364 } 365 } 366 367 @Override 368 public void exit() { 369 // NOTE: This removes the delayed message posted by enter() but will inadvertently 370 // remove any other CMD_FORCE_REEVALUATION in the message queue. At the moment this 371 // is harmless. If in the future this becomes problematic a different message could 372 // be used. 373 removeMessages(CMD_FORCE_REEVALUATION); 374 } 375 } 376 377 // Being in the ValidatedState State indicates a Network is: 378 // - Successfully validated, or 379 // - Wanted "as is" by the user, or 380 // - Does not satsify the default NetworkRequest and so validation has been skipped. 381 private class ValidatedState extends State { 382 @Override 383 public void enter() { 384 if (DBG) log("Validated"); 385 mConnectivityServiceHandler.sendMessage(obtainMessage(EVENT_NETWORK_TESTED, 386 NETWORK_TEST_RESULT_VALID, 0, mNetworkAgentInfo)); 387 } 388 389 @Override 390 public boolean processMessage(Message message) { 391 if (DBG) log(getName() + message.toString()); 392 switch (message.what) { 393 case CMD_NETWORK_CONNECTED: 394 transitionTo(mValidatedState); 395 return HANDLED; 396 default: 397 return NOT_HANDLED; 398 } 399 } 400 } 401 402 // Being in the MaybeNotifyState State indicates the user may have been notified that sign-in 403 // is required. This State takes care to clear the notification upon exit from the State. 404 private class MaybeNotifyState extends State { 405 @Override 406 public void exit() { 407 Message message = obtainMessage(EVENT_PROVISIONING_NOTIFICATION, 0, 408 mNetworkAgentInfo.network.netId, null); 409 mConnectivityServiceHandler.sendMessage(message); 410 } 411 } 412 413 // Being in the EvaluatingState State indicates the Network is being evaluated for internet 414 // connectivity. 415 private class EvaluatingState extends State { 416 private int mRetries; 417 418 @Override 419 public void enter() { 420 mRetries = 0; 421 sendMessage(CMD_REEVALUATE, ++mReevaluateToken, 0); 422 if (mUidResponsibleForReeval != INVALID_UID) { 423 TrafficStats.setThreadStatsUid(mUidResponsibleForReeval); 424 mUidResponsibleForReeval = INVALID_UID; 425 } 426 } 427 428 @Override 429 public boolean processMessage(Message message) { 430 if (DBG) log(getName() + message.toString()); 431 switch (message.what) { 432 case CMD_REEVALUATE: 433 if (message.arg1 != mReevaluateToken) 434 return HANDLED; 435 // Don't bother validating networks that don't satisify the default request. 436 // This includes: 437 // - VPNs which can be considered explicitly desired by the user and the 438 // user's desire trumps whether the network validates. 439 // - Networks that don't provide internet access. It's unclear how to 440 // validate such networks. 441 // - Untrusted networks. It's unsafe to prompt the user to sign-in to 442 // such networks and the user didn't express interest in connecting to 443 // such networks (an app did) so the user may be unhappily surprised when 444 // asked to sign-in to a network they didn't want to connect to in the 445 // first place. Validation could be done to adjust the network scores 446 // however these networks are app-requested and may not be intended for 447 // general usage, in which case general validation may not be an accurate 448 // measure of the network's quality. Only the app knows how to evaluate 449 // the network so don't bother validating here. Furthermore sending HTTP 450 // packets over the network may be undesirable, for example an extremely 451 // expensive metered network, or unwanted leaking of the User Agent string. 452 if (!mDefaultRequest.networkCapabilities.satisfiedByNetworkCapabilities( 453 mNetworkAgentInfo.networkCapabilities)) { 454 transitionTo(mValidatedState); 455 return HANDLED; 456 } 457 // Note: This call to isCaptivePortal() could take minutes. Resolving the 458 // server's IP addresses could hit the DNS timeout and attempting connections 459 // to each of the server's several (e.g. 11) IP addresses could each take 460 // SOCKET_TIMEOUT_MS. During this time this StateMachine will be unresponsive. 461 // isCaptivePortal() could be executed on another Thread if this is found to 462 // cause problems. 463 int httpResponseCode = isCaptivePortal(); 464 if (httpResponseCode == 204) { 465 transitionTo(mValidatedState); 466 } else if (httpResponseCode >= 200 && httpResponseCode <= 399) { 467 transitionTo(mCaptivePortalState); 468 } else if (++mRetries > MAX_RETRIES) { 469 transitionTo(mOfflineState); 470 } else if (mReevaluateDelayMs >= 0) { 471 Message msg = obtainMessage(CMD_REEVALUATE, ++mReevaluateToken, 0); 472 sendMessageDelayed(msg, mReevaluateDelayMs); 473 } 474 return HANDLED; 475 case CMD_FORCE_REEVALUATION: 476 // Ignore duplicate requests. 477 return HANDLED; 478 default: 479 return NOT_HANDLED; 480 } 481 } 482 483 @Override 484 public void exit() { 485 TrafficStats.clearThreadStatsUid(); 486 } 487 } 488 489 // BroadcastReceiver that waits for a particular Intent and then posts a message. 490 private class CustomIntentReceiver extends BroadcastReceiver { 491 private final int mToken; 492 private final int mWhat; 493 private final String mAction; 494 CustomIntentReceiver(String action, int token, int what) { 495 mToken = token; 496 mWhat = what; 497 mAction = action + "_" + mNetworkAgentInfo.network.netId + "_" + token; 498 mContext.registerReceiver(this, new IntentFilter(mAction)); 499 } 500 public PendingIntent getPendingIntent() { 501 return PendingIntent.getBroadcast(mContext, 0, new Intent(mAction), 0); 502 } 503 @Override 504 public void onReceive(Context context, Intent intent) { 505 if (intent.getAction().equals(mAction)) sendMessage(obtainMessage(mWhat, mToken)); 506 } 507 } 508 509 private class CaptivePortalLoggedInBroadcastReceiver extends BroadcastReceiver { 510 @Override 511 public void onReceive(Context context, Intent intent) { 512 if (Integer.parseInt(intent.getStringExtra(Intent.EXTRA_TEXT)) == 513 mNetworkAgentInfo.network.netId && 514 mCaptivePortalLoggedInResponseToken.equals( 515 intent.getStringExtra(RESPONSE_TOKEN))) { 516 sendMessage(obtainMessage(CMD_CAPTIVE_PORTAL_APP_FINISHED, 517 Integer.parseInt(intent.getStringExtra(LOGGED_IN_RESULT)), 0)); 518 } 519 } 520 } 521 522 // Being in the CaptivePortalState State indicates a captive portal was detected and the user 523 // has been shown a notification to sign-in. 524 private class CaptivePortalState extends State { 525 @Override 526 public void enter() { 527 mConnectivityServiceHandler.sendMessage(obtainMessage(EVENT_NETWORK_TESTED, 528 NETWORK_TEST_RESULT_INVALID, 0, mNetworkAgentInfo)); 529 530 // Assemble Intent to launch captive portal sign-in app. 531 final Intent intent = new Intent(Intent.ACTION_SEND); 532 // Intent cannot use extras because PendingIntent.getActivity will merge matching 533 // Intents erasing extras. Use data instead of extras to encode NetID. 534 intent.setData(Uri.fromParts("netid", Integer.toString(mNetworkAgentInfo.network.netId), 535 mCaptivePortalLoggedInResponseToken)); 536 intent.setComponent(new ComponentName("com.android.captiveportallogin", 537 "com.android.captiveportallogin.CaptivePortalLoginActivity")); 538 intent.setFlags(Intent.FLAG_ACTIVITY_BROUGHT_TO_FRONT | Intent.FLAG_ACTIVITY_NEW_TASK); 539 540 if (mCaptivePortalLoggedInBroadcastReceiver == null) { 541 // Wait for result. 542 mCaptivePortalLoggedInBroadcastReceiver = 543 new CaptivePortalLoggedInBroadcastReceiver(); 544 final IntentFilter filter = new IntentFilter(ACTION_CAPTIVE_PORTAL_LOGGED_IN); 545 mContext.registerReceiver(mCaptivePortalLoggedInBroadcastReceiver, filter); 546 } 547 // Initiate notification to sign-in. 548 Message message = obtainMessage(EVENT_PROVISIONING_NOTIFICATION, 1, 549 mNetworkAgentInfo.network.netId, 550 PendingIntent.getActivity(mContext, 0, intent, 0)); 551 mConnectivityServiceHandler.sendMessage(message); 552 } 553 554 @Override 555 public boolean processMessage(Message message) { 556 if (DBG) log(getName() + message.toString()); 557 return NOT_HANDLED; 558 } 559 } 560 561 // Being in the LingeringState State indicates a Network's validated bit is true and it once 562 // was the highest scoring Network satisfying a particular NetworkRequest, but since then 563 // another Network satsified the NetworkRequest with a higher score and hence this Network 564 // is "lingered" for a fixed period of time before it is disconnected. This period of time 565 // allows apps to wrap up communication and allows for seamless reactivation if the other 566 // higher scoring Network happens to disconnect. 567 private class LingeringState extends State { 568 private static final String ACTION_LINGER_EXPIRED = "android.net.netmon.lingerExpired"; 569 570 private CustomIntentReceiver mBroadcastReceiver; 571 private PendingIntent mIntent; 572 573 @Override 574 public void enter() { 575 mLingerToken = new Random().nextInt(); 576 mBroadcastReceiver = new CustomIntentReceiver(ACTION_LINGER_EXPIRED, mLingerToken, 577 CMD_LINGER_EXPIRED); 578 mIntent = mBroadcastReceiver.getPendingIntent(); 579 long wakeupTime = SystemClock.elapsedRealtime() + mLingerDelayMs; 580 mAlarmManager.setWindow(AlarmManager.ELAPSED_REALTIME_WAKEUP, wakeupTime, 581 // Give a specific window so we aren't subject to unknown inexactitude. 582 mLingerDelayMs / 6, mIntent); 583 } 584 585 @Override 586 public boolean processMessage(Message message) { 587 if (DBG) log(getName() + message.toString()); 588 switch (message.what) { 589 case CMD_NETWORK_CONNECTED: 590 // Go straight to active as we've already evaluated. 591 transitionTo(mValidatedState); 592 return HANDLED; 593 case CMD_LINGER_EXPIRED: 594 if (message.arg1 != mLingerToken) 595 return HANDLED; 596 mConnectivityServiceHandler.sendMessage( 597 obtainMessage(EVENT_NETWORK_LINGER_COMPLETE, mNetworkAgentInfo)); 598 return HANDLED; 599 case CMD_FORCE_REEVALUATION: 600 // Ignore reevaluation attempts when lingering. A reevaluation could result 601 // in a transition to the validated state which would abort the linger 602 // timeout. Lingering is the result of score assessment; validity is 603 // irrelevant. 604 return HANDLED; 605 case CMD_CAPTIVE_PORTAL_APP_FINISHED: 606 // Ignore user network determination as this could abort linger timeout. 607 // Networks are only lingered once validated because: 608 // - Unvalidated networks are never lingered (see rematchNetworkAndRequests). 609 // - Once validated, a Network's validated bit is never cleared. 610 // Since networks are only lingered after being validated a user's 611 // determination will not change the death sentence that lingering entails: 612 // - If the user wants to use the network or bypasses the captive portal, 613 // the network's score will not be increased beyond its current value 614 // because it is already validated. Without a score increase there is no 615 // chance of reactivation (i.e. aborting linger timeout). 616 // - If the user does not want the network, lingering will disconnect the 617 // network anyhow. 618 return HANDLED; 619 default: 620 return NOT_HANDLED; 621 } 622 } 623 624 @Override 625 public void exit() { 626 mAlarmManager.cancel(mIntent); 627 mContext.unregisterReceiver(mBroadcastReceiver); 628 } 629 } 630 631 /** 632 * Do a URL fetch on a known server to see if we get the data we expect. 633 * Returns HTTP response code. 634 */ 635 private int isCaptivePortal() { 636 if (!mIsCaptivePortalCheckEnabled) return 204; 637 638 HttpURLConnection urlConnection = null; 639 int httpResponseCode = 599; 640 try { 641 URL url = new URL("http", mServer, "/generate_204"); 642 if (DBG) { 643 log("Checking " + url.toString() + " on " + 644 mNetworkAgentInfo.networkInfo.getExtraInfo()); 645 } 646 urlConnection = (HttpURLConnection) mNetworkAgentInfo.network.openConnection(url); 647 urlConnection.setInstanceFollowRedirects(false); 648 urlConnection.setConnectTimeout(SOCKET_TIMEOUT_MS); 649 urlConnection.setReadTimeout(SOCKET_TIMEOUT_MS); 650 urlConnection.setUseCaches(false); 651 652 // Time how long it takes to get a response to our request 653 long requestTimestamp = SystemClock.elapsedRealtime(); 654 655 urlConnection.getInputStream(); 656 657 // Time how long it takes to get a response to our request 658 long responseTimestamp = SystemClock.elapsedRealtime(); 659 660 httpResponseCode = urlConnection.getResponseCode(); 661 if (DBG) { 662 log("isCaptivePortal: ret=" + httpResponseCode + 663 " headers=" + urlConnection.getHeaderFields()); 664 } 665 // NOTE: We may want to consider an "HTTP/1.0 204" response to be a captive 666 // portal. The only example of this seen so far was a captive portal. For 667 // the time being go with prior behavior of assuming it's not a captive 668 // portal. If it is considered a captive portal, a different sign-in URL 669 // is needed (i.e. can't browse a 204). This could be the result of an HTTP 670 // proxy server. 671 672 // Consider 200 response with "Content-length=0" to not be a captive portal. 673 // There's no point in considering this a captive portal as the user cannot 674 // sign-in to an empty page. Probably the result of a broken transparent proxy. 675 // See http://b/9972012. 676 if (httpResponseCode == 200 && urlConnection.getContentLength() == 0) { 677 if (DBG) log("Empty 200 response interpreted as 204 response."); 678 httpResponseCode = 204; 679 } 680 681 sendNetworkConditionsBroadcast(true /* response received */, 682 httpResponseCode != 204 /* isCaptivePortal */, 683 requestTimestamp, responseTimestamp); 684 } catch (IOException e) { 685 if (DBG) log("Probably not a portal: exception " + e); 686 if (httpResponseCode == 599) { 687 // TODO: Ping gateway and DNS server and log results. 688 } 689 } finally { 690 if (urlConnection != null) { 691 urlConnection.disconnect(); 692 } 693 } 694 return httpResponseCode; 695 } 696 697 /** 698 * @param responseReceived - whether or not we received a valid HTTP response to our request. 699 * If false, isCaptivePortal and responseTimestampMs are ignored 700 * TODO: This should be moved to the transports. The latency could be passed to the transports 701 * along with the captive portal result. Currently the TYPE_MOBILE broadcasts appear unused so 702 * perhaps this could just be added to the WiFi transport only. 703 */ 704 private void sendNetworkConditionsBroadcast(boolean responseReceived, boolean isCaptivePortal, 705 long requestTimestampMs, long responseTimestampMs) { 706 if (Settings.Global.getInt(mContext.getContentResolver(), 707 Settings.Global.WIFI_SCAN_ALWAYS_AVAILABLE, 0) == 0) { 708 if (DBG) log("Don't send network conditions - lacking user consent."); 709 return; 710 } 711 712 if (systemReady == false) return; 713 714 Intent latencyBroadcast = new Intent(ACTION_NETWORK_CONDITIONS_MEASURED); 715 switch (mNetworkAgentInfo.networkInfo.getType()) { 716 case ConnectivityManager.TYPE_WIFI: 717 WifiInfo currentWifiInfo = mWifiManager.getConnectionInfo(); 718 if (currentWifiInfo != null) { 719 // NOTE: getSSID()'s behavior changed in API 17; before that, SSIDs were not 720 // surrounded by double quotation marks (thus violating the Javadoc), but this 721 // was changed to match the Javadoc in API 17. Since clients may have started 722 // sanitizing the output of this method since API 17 was released, we should 723 // not change it here as it would become impossible to tell whether the SSID is 724 // simply being surrounded by quotes due to the API, or whether those quotes 725 // are actually part of the SSID. 726 latencyBroadcast.putExtra(EXTRA_SSID, currentWifiInfo.getSSID()); 727 latencyBroadcast.putExtra(EXTRA_BSSID, currentWifiInfo.getBSSID()); 728 } else { 729 if (DBG) logw("network info is TYPE_WIFI but no ConnectionInfo found"); 730 return; 731 } 732 break; 733 case ConnectivityManager.TYPE_MOBILE: 734 latencyBroadcast.putExtra(EXTRA_NETWORK_TYPE, mTelephonyManager.getNetworkType()); 735 List<CellInfo> info = mTelephonyManager.getAllCellInfo(); 736 if (info == null) return; 737 int numRegisteredCellInfo = 0; 738 for (CellInfo cellInfo : info) { 739 if (cellInfo.isRegistered()) { 740 numRegisteredCellInfo++; 741 if (numRegisteredCellInfo > 1) { 742 if (DBG) log("more than one registered CellInfo. Can't " + 743 "tell which is active. Bailing."); 744 return; 745 } 746 if (cellInfo instanceof CellInfoCdma) { 747 CellIdentityCdma cellId = ((CellInfoCdma) cellInfo).getCellIdentity(); 748 latencyBroadcast.putExtra(EXTRA_CELL_ID, cellId); 749 } else if (cellInfo instanceof CellInfoGsm) { 750 CellIdentityGsm cellId = ((CellInfoGsm) cellInfo).getCellIdentity(); 751 latencyBroadcast.putExtra(EXTRA_CELL_ID, cellId); 752 } else if (cellInfo instanceof CellInfoLte) { 753 CellIdentityLte cellId = ((CellInfoLte) cellInfo).getCellIdentity(); 754 latencyBroadcast.putExtra(EXTRA_CELL_ID, cellId); 755 } else if (cellInfo instanceof CellInfoWcdma) { 756 CellIdentityWcdma cellId = ((CellInfoWcdma) cellInfo).getCellIdentity(); 757 latencyBroadcast.putExtra(EXTRA_CELL_ID, cellId); 758 } else { 759 if (DBG) logw("Registered cellinfo is unrecognized"); 760 return; 761 } 762 } 763 } 764 break; 765 default: 766 return; 767 } 768 latencyBroadcast.putExtra(EXTRA_CONNECTIVITY_TYPE, mNetworkAgentInfo.networkInfo.getType()); 769 latencyBroadcast.putExtra(EXTRA_RESPONSE_RECEIVED, responseReceived); 770 latencyBroadcast.putExtra(EXTRA_REQUEST_TIMESTAMP_MS, requestTimestampMs); 771 772 if (responseReceived) { 773 latencyBroadcast.putExtra(EXTRA_IS_CAPTIVE_PORTAL, isCaptivePortal); 774 latencyBroadcast.putExtra(EXTRA_RESPONSE_TIMESTAMP_MS, responseTimestampMs); 775 } 776 mContext.sendBroadcastAsUser(latencyBroadcast, UserHandle.CURRENT, 777 PERMISSION_ACCESS_NETWORK_CONDITIONS); 778 } 779} 780