NetworkMonitor.java revision 351bfad339ede00a81862b3b57234d7a32067279
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 * arg2 = Number of evaluation attempts to make. (If 0, make INITIAL_ATTEMPTS attempts.) 167 */ 168 public static final int CMD_FORCE_REEVALUATION = BASE + 8; 169 170 /** 171 * Message to self indicating captive portal app finished. 172 * arg1 = one of: CAPTIVE_PORTAL_APP_RETURN_APPEASED, 173 * CAPTIVE_PORTAL_APP_RETURN_UNWANTED, 174 * CAPTIVE_PORTAL_APP_RETURN_WANTED_AS_IS 175 */ 176 private static final int CMD_CAPTIVE_PORTAL_APP_FINISHED = BASE + 9; 177 178 /** 179 * Request ConnectivityService display provisioning notification. 180 * arg1 = Whether to make the notification visible. 181 * arg2 = NetID. 182 * obj = Intent to be launched when notification selected by user, null if !arg1. 183 */ 184 public static final int EVENT_PROVISIONING_NOTIFICATION = BASE + 10; 185 186 /** 187 * Message to self indicating sign-in app bypassed captive portal. 188 */ 189 private static final int EVENT_APP_BYPASSED_CAPTIVE_PORTAL = BASE + 11; 190 191 /** 192 * Message to self indicating no sign-in app responded. 193 */ 194 private static final int EVENT_NO_APP_RESPONSE = BASE + 12; 195 196 /** 197 * Message to self indicating sign-in app indicates sign-in is not possible. 198 */ 199 private static final int EVENT_APP_INDICATES_SIGN_IN_IMPOSSIBLE = BASE + 13; 200 201 /** 202 * Return codes from captive portal sign-in app. 203 */ 204 public static final int CAPTIVE_PORTAL_APP_RETURN_APPEASED = 0; 205 public static final int CAPTIVE_PORTAL_APP_RETURN_UNWANTED = 1; 206 public static final int CAPTIVE_PORTAL_APP_RETURN_WANTED_AS_IS = 2; 207 208 private static final String LINGER_DELAY_PROPERTY = "persist.netmon.linger"; 209 // Default to 30s linger time-out. 210 private static final int DEFAULT_LINGER_DELAY_MS = 30000; 211 private final int mLingerDelayMs; 212 private int mLingerToken = 0; 213 214 // Negative values disable reevaluation. 215 private static final String REEVALUATE_DELAY_PROPERTY = "persist.netmon.reeval_delay"; 216 // When connecting, attempt to validate 3 times, pausing 5s between them. 217 private static final int DEFAULT_REEVALUATE_DELAY_MS = 5000; 218 private static final int INITIAL_ATTEMPTS = 3; 219 // If a network is not validated, make one attempt every 10 mins to see if it starts working. 220 private static final int REEVALUATE_PAUSE_MS = 10*60*1000; 221 private static final int PERIODIC_ATTEMPTS = 1; 222 // When an application calls reportBadNetwork, only make one attempt. 223 private static final int REEVALUATE_ATTEMPTS = 1; 224 private final int mReevaluateDelayMs; 225 private int mReevaluateToken = 0; 226 private static final int INVALID_UID = -1; 227 private int mUidResponsibleForReeval = INVALID_UID; 228 229 private final Context mContext; 230 private final Handler mConnectivityServiceHandler; 231 private final NetworkAgentInfo mNetworkAgentInfo; 232 private final TelephonyManager mTelephonyManager; 233 private final WifiManager mWifiManager; 234 private final AlarmManager mAlarmManager; 235 private final NetworkRequest mDefaultRequest; 236 237 private String mServer; 238 private boolean mIsCaptivePortalCheckEnabled = false; 239 240 // Set if the user explicitly selected "Do not use this network" in captive portal sign-in app. 241 private boolean mUserDoesNotWant = false; 242 243 // How many times we should attempt validation. Only checked in EvaluatingState; must be set 244 // before entering EvaluatingState. Note that whatever code causes us to transition to 245 // EvaluatingState last decides how many attempts will be made, so if one codepath were to 246 // enter EvaluatingState with a specific number of attempts, and then another were to enter it 247 // with a different number of attempts, the second number would be used. This is not currently 248 // a problem because EvaluatingState is not reentrant. 249 private int mMaxAttempts; 250 251 public boolean systemReady = false; 252 253 private final State mDefaultState = new DefaultState(); 254 private final State mOfflineState = new OfflineState(); 255 private final State mValidatedState = new ValidatedState(); 256 private final State mMaybeNotifyState = new MaybeNotifyState(); 257 private final State mEvaluatingState = new EvaluatingState(); 258 private final State mCaptivePortalState = new CaptivePortalState(); 259 private final State mLingeringState = new LingeringState(); 260 261 private CaptivePortalLoggedInBroadcastReceiver mCaptivePortalLoggedInBroadcastReceiver = null; 262 private String mCaptivePortalLoggedInResponseToken = null; 263 264 public NetworkMonitor(Context context, Handler handler, NetworkAgentInfo networkAgentInfo, 265 NetworkRequest defaultRequest) { 266 // Add suffix indicating which NetworkMonitor we're talking about. 267 super(TAG + networkAgentInfo.name()); 268 269 mContext = context; 270 mConnectivityServiceHandler = handler; 271 mNetworkAgentInfo = networkAgentInfo; 272 mTelephonyManager = (TelephonyManager) context.getSystemService(Context.TELEPHONY_SERVICE); 273 mWifiManager = (WifiManager) context.getSystemService(Context.WIFI_SERVICE); 274 mAlarmManager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE); 275 mDefaultRequest = defaultRequest; 276 277 addState(mDefaultState); 278 addState(mOfflineState, mDefaultState); 279 addState(mValidatedState, mDefaultState); 280 addState(mMaybeNotifyState, mDefaultState); 281 addState(mEvaluatingState, mMaybeNotifyState); 282 addState(mCaptivePortalState, mMaybeNotifyState); 283 addState(mLingeringState, mDefaultState); 284 setInitialState(mDefaultState); 285 286 mServer = Settings.Global.getString(mContext.getContentResolver(), 287 Settings.Global.CAPTIVE_PORTAL_SERVER); 288 if (mServer == null) mServer = DEFAULT_SERVER; 289 290 mLingerDelayMs = SystemProperties.getInt(LINGER_DELAY_PROPERTY, DEFAULT_LINGER_DELAY_MS); 291 mReevaluateDelayMs = SystemProperties.getInt(REEVALUATE_DELAY_PROPERTY, 292 DEFAULT_REEVALUATE_DELAY_MS); 293 294 mIsCaptivePortalCheckEnabled = Settings.Global.getInt(mContext.getContentResolver(), 295 Settings.Global.CAPTIVE_PORTAL_DETECTION_ENABLED, 1) == 1; 296 297 mCaptivePortalLoggedInResponseToken = String.valueOf(new Random().nextLong()); 298 299 start(); 300 } 301 302 @Override 303 protected void log(String s) { 304 Log.d(TAG + "/" + mNetworkAgentInfo.name(), s); 305 } 306 307 // DefaultState is the parent of all States. It exists only to handle CMD_* messages but 308 // does not entail any real state (hence no enter() or exit() routines). 309 private class DefaultState extends State { 310 @Override 311 public boolean processMessage(Message message) { 312 if (DBG) log(getName() + message.toString()); 313 switch (message.what) { 314 case CMD_NETWORK_LINGER: 315 if (DBG) log("Lingering"); 316 transitionTo(mLingeringState); 317 return HANDLED; 318 case CMD_NETWORK_CONNECTED: 319 if (DBG) log("Connected"); 320 mMaxAttempts = INITIAL_ATTEMPTS; 321 transitionTo(mEvaluatingState); 322 return HANDLED; 323 case CMD_NETWORK_DISCONNECTED: 324 if (DBG) log("Disconnected - quitting"); 325 if (mCaptivePortalLoggedInBroadcastReceiver != null) { 326 mContext.unregisterReceiver(mCaptivePortalLoggedInBroadcastReceiver); 327 mCaptivePortalLoggedInBroadcastReceiver = null; 328 } 329 quit(); 330 return HANDLED; 331 case CMD_FORCE_REEVALUATION: 332 if (DBG) log("Forcing reevaluation"); 333 mUidResponsibleForReeval = message.arg1; 334 mMaxAttempts = message.arg2 != 0 ? message.arg2 : REEVALUATE_ATTEMPTS; 335 transitionTo(mEvaluatingState); 336 return HANDLED; 337 case CMD_CAPTIVE_PORTAL_APP_FINISHED: 338 // Previous token was broadcast, come up with a new one. 339 mCaptivePortalLoggedInResponseToken = String.valueOf(new Random().nextLong()); 340 switch (message.arg1) { 341 case CAPTIVE_PORTAL_APP_RETURN_APPEASED: 342 case CAPTIVE_PORTAL_APP_RETURN_WANTED_AS_IS: 343 transitionTo(mValidatedState); 344 break; 345 case CAPTIVE_PORTAL_APP_RETURN_UNWANTED: 346 mUserDoesNotWant = true; 347 // TODO: Should teardown network. 348 transitionTo(mOfflineState); 349 break; 350 } 351 return HANDLED; 352 default: 353 return HANDLED; 354 } 355 } 356 } 357 358 // Being in the OfflineState State indicates a Network is unwanted or failed validation. 359 private class OfflineState extends State { 360 @Override 361 public void enter() { 362 mConnectivityServiceHandler.sendMessage(obtainMessage(EVENT_NETWORK_TESTED, 363 NETWORK_TEST_RESULT_INVALID, 0, mNetworkAgentInfo)); 364 if (!mUserDoesNotWant) { 365 sendMessageDelayed(CMD_FORCE_REEVALUATION, 0 /* no UID */, 366 PERIODIC_ATTEMPTS, REEVALUATE_PAUSE_MS); 367 } 368 } 369 370 @Override 371 public boolean processMessage(Message message) { 372 if (DBG) log(getName() + message.toString()); 373 switch (message.what) { 374 case CMD_FORCE_REEVALUATION: 375 // If the user has indicated they explicitly do not want to use this network, 376 // don't allow a reevaluation as this will be pointless and could result in 377 // the user being annoyed with repeated unwanted notifications. 378 return mUserDoesNotWant ? HANDLED : NOT_HANDLED; 379 default: 380 return NOT_HANDLED; 381 } 382 } 383 384 @Override 385 public void exit() { 386 // NOTE: This removes the delayed message posted by enter() but will inadvertently 387 // remove any other CMD_FORCE_REEVALUATION in the message queue. At the moment this 388 // is harmless. If in the future this becomes problematic a different message could 389 // be used. 390 removeMessages(CMD_FORCE_REEVALUATION); 391 } 392 } 393 394 // Being in the ValidatedState State indicates a Network is: 395 // - Successfully validated, or 396 // - Wanted "as is" by the user, or 397 // - Does not satsify the default NetworkRequest and so validation has been skipped. 398 private class ValidatedState extends State { 399 @Override 400 public void enter() { 401 if (DBG) log("Validated"); 402 mConnectivityServiceHandler.sendMessage(obtainMessage(EVENT_NETWORK_TESTED, 403 NETWORK_TEST_RESULT_VALID, 0, mNetworkAgentInfo)); 404 } 405 406 @Override 407 public boolean processMessage(Message message) { 408 if (DBG) log(getName() + message.toString()); 409 switch (message.what) { 410 case CMD_NETWORK_CONNECTED: 411 transitionTo(mValidatedState); 412 return HANDLED; 413 default: 414 return NOT_HANDLED; 415 } 416 } 417 } 418 419 // Being in the MaybeNotifyState State indicates the user may have been notified that sign-in 420 // is required. This State takes care to clear the notification upon exit from the State. 421 private class MaybeNotifyState extends State { 422 @Override 423 public void exit() { 424 Message message = obtainMessage(EVENT_PROVISIONING_NOTIFICATION, 0, 425 mNetworkAgentInfo.network.netId, null); 426 mConnectivityServiceHandler.sendMessage(message); 427 } 428 } 429 430 // Being in the EvaluatingState State indicates the Network is being evaluated for internet 431 // connectivity. 432 private class EvaluatingState extends State { 433 private int mAttempt; 434 435 @Override 436 public void enter() { 437 mAttempt = 1; 438 sendMessage(CMD_REEVALUATE, ++mReevaluateToken, 0); 439 if (mUidResponsibleForReeval != INVALID_UID) { 440 TrafficStats.setThreadStatsUid(mUidResponsibleForReeval); 441 mUidResponsibleForReeval = INVALID_UID; 442 } 443 } 444 445 @Override 446 public boolean processMessage(Message message) { 447 if (DBG) log(getName() + message.toString()); 448 switch (message.what) { 449 case CMD_REEVALUATE: 450 if (message.arg1 != mReevaluateToken) 451 return HANDLED; 452 // Don't bother validating networks that don't satisify the default request. 453 // This includes: 454 // - VPNs which can be considered explicitly desired by the user and the 455 // user's desire trumps whether the network validates. 456 // - Networks that don't provide internet access. It's unclear how to 457 // validate such networks. 458 // - Untrusted networks. It's unsafe to prompt the user to sign-in to 459 // such networks and the user didn't express interest in connecting to 460 // such networks (an app did) so the user may be unhappily surprised when 461 // asked to sign-in to a network they didn't want to connect to in the 462 // first place. Validation could be done to adjust the network scores 463 // however these networks are app-requested and may not be intended for 464 // general usage, in which case general validation may not be an accurate 465 // measure of the network's quality. Only the app knows how to evaluate 466 // the network so don't bother validating here. Furthermore sending HTTP 467 // packets over the network may be undesirable, for example an extremely 468 // expensive metered network, or unwanted leaking of the User Agent string. 469 if (!mDefaultRequest.networkCapabilities.satisfiedByNetworkCapabilities( 470 mNetworkAgentInfo.networkCapabilities)) { 471 transitionTo(mValidatedState); 472 return HANDLED; 473 } 474 // Note: This call to isCaptivePortal() could take up to a minute. Resolving the 475 // server's IP addresses could hit the DNS timeout, and attempting connections 476 // to each of the server's several IP addresses (currently one IPv4 and one 477 // IPv6) could each take SOCKET_TIMEOUT_MS. During this time this StateMachine 478 // will be unresponsive. isCaptivePortal() could be executed on another Thread 479 // if this is found to cause problems. 480 int httpResponseCode = isCaptivePortal(); 481 if (httpResponseCode == 204) { 482 transitionTo(mValidatedState); 483 } else if (httpResponseCode >= 200 && httpResponseCode <= 399) { 484 transitionTo(mCaptivePortalState); 485 } else if (++mAttempt > mMaxAttempts) { 486 transitionTo(mOfflineState); 487 } else if (mReevaluateDelayMs >= 0) { 488 Message msg = obtainMessage(CMD_REEVALUATE, ++mReevaluateToken, 0); 489 sendMessageDelayed(msg, mReevaluateDelayMs); 490 } 491 return HANDLED; 492 case CMD_FORCE_REEVALUATION: 493 // Ignore duplicate requests. 494 return HANDLED; 495 default: 496 return NOT_HANDLED; 497 } 498 } 499 500 @Override 501 public void exit() { 502 TrafficStats.clearThreadStatsUid(); 503 } 504 } 505 506 // BroadcastReceiver that waits for a particular Intent and then posts a message. 507 private class CustomIntentReceiver extends BroadcastReceiver { 508 private final int mToken; 509 private final int mWhat; 510 private final String mAction; 511 CustomIntentReceiver(String action, int token, int what) { 512 mToken = token; 513 mWhat = what; 514 mAction = action + "_" + mNetworkAgentInfo.network.netId + "_" + token; 515 mContext.registerReceiver(this, new IntentFilter(mAction)); 516 } 517 public PendingIntent getPendingIntent() { 518 return PendingIntent.getBroadcast(mContext, 0, new Intent(mAction), 0); 519 } 520 @Override 521 public void onReceive(Context context, Intent intent) { 522 if (intent.getAction().equals(mAction)) sendMessage(obtainMessage(mWhat, mToken)); 523 } 524 } 525 526 private class CaptivePortalLoggedInBroadcastReceiver extends BroadcastReceiver { 527 @Override 528 public void onReceive(Context context, Intent intent) { 529 if (Integer.parseInt(intent.getStringExtra(Intent.EXTRA_TEXT)) == 530 mNetworkAgentInfo.network.netId && 531 mCaptivePortalLoggedInResponseToken.equals( 532 intent.getStringExtra(RESPONSE_TOKEN))) { 533 sendMessage(obtainMessage(CMD_CAPTIVE_PORTAL_APP_FINISHED, 534 Integer.parseInt(intent.getStringExtra(LOGGED_IN_RESULT)), 0)); 535 } 536 } 537 } 538 539 // Being in the CaptivePortalState State indicates a captive portal was detected and the user 540 // has been shown a notification to sign-in. 541 private class CaptivePortalState extends State { 542 @Override 543 public void enter() { 544 mConnectivityServiceHandler.sendMessage(obtainMessage(EVENT_NETWORK_TESTED, 545 NETWORK_TEST_RESULT_INVALID, 0, mNetworkAgentInfo)); 546 547 // Assemble Intent to launch captive portal sign-in app. 548 final Intent intent = new Intent(Intent.ACTION_SEND); 549 // Intent cannot use extras because PendingIntent.getActivity will merge matching 550 // Intents erasing extras. Use data instead of extras to encode NetID. 551 intent.setData(Uri.fromParts("netid", Integer.toString(mNetworkAgentInfo.network.netId), 552 mCaptivePortalLoggedInResponseToken)); 553 intent.setComponent(new ComponentName("com.android.captiveportallogin", 554 "com.android.captiveportallogin.CaptivePortalLoginActivity")); 555 intent.setFlags(Intent.FLAG_ACTIVITY_BROUGHT_TO_FRONT | Intent.FLAG_ACTIVITY_NEW_TASK); 556 557 if (mCaptivePortalLoggedInBroadcastReceiver == null) { 558 // Wait for result. 559 mCaptivePortalLoggedInBroadcastReceiver = 560 new CaptivePortalLoggedInBroadcastReceiver(); 561 final IntentFilter filter = new IntentFilter(ACTION_CAPTIVE_PORTAL_LOGGED_IN); 562 mContext.registerReceiver(mCaptivePortalLoggedInBroadcastReceiver, filter); 563 } 564 // Initiate notification to sign-in. 565 Message message = obtainMessage(EVENT_PROVISIONING_NOTIFICATION, 1, 566 mNetworkAgentInfo.network.netId, 567 PendingIntent.getActivity(mContext, 0, intent, 0)); 568 mConnectivityServiceHandler.sendMessage(message); 569 } 570 571 @Override 572 public boolean processMessage(Message message) { 573 if (DBG) log(getName() + message.toString()); 574 return NOT_HANDLED; 575 } 576 } 577 578 // Being in the LingeringState State indicates a Network's validated bit is true and it once 579 // was the highest scoring Network satisfying a particular NetworkRequest, but since then 580 // another Network satsified the NetworkRequest with a higher score and hence this Network 581 // is "lingered" for a fixed period of time before it is disconnected. This period of time 582 // allows apps to wrap up communication and allows for seamless reactivation if the other 583 // higher scoring Network happens to disconnect. 584 private class LingeringState extends State { 585 private static final String ACTION_LINGER_EXPIRED = "android.net.netmon.lingerExpired"; 586 587 private CustomIntentReceiver mBroadcastReceiver; 588 private PendingIntent mIntent; 589 590 @Override 591 public void enter() { 592 mLingerToken = new Random().nextInt(); 593 mBroadcastReceiver = new CustomIntentReceiver(ACTION_LINGER_EXPIRED, mLingerToken, 594 CMD_LINGER_EXPIRED); 595 mIntent = mBroadcastReceiver.getPendingIntent(); 596 long wakeupTime = SystemClock.elapsedRealtime() + mLingerDelayMs; 597 mAlarmManager.setWindow(AlarmManager.ELAPSED_REALTIME_WAKEUP, wakeupTime, 598 // Give a specific window so we aren't subject to unknown inexactitude. 599 mLingerDelayMs / 6, mIntent); 600 } 601 602 @Override 603 public boolean processMessage(Message message) { 604 if (DBG) log(getName() + message.toString()); 605 switch (message.what) { 606 case CMD_NETWORK_CONNECTED: 607 // Go straight to active as we've already evaluated. 608 transitionTo(mValidatedState); 609 return HANDLED; 610 case CMD_LINGER_EXPIRED: 611 if (message.arg1 != mLingerToken) 612 return HANDLED; 613 mConnectivityServiceHandler.sendMessage( 614 obtainMessage(EVENT_NETWORK_LINGER_COMPLETE, mNetworkAgentInfo)); 615 return HANDLED; 616 case CMD_FORCE_REEVALUATION: 617 // Ignore reevaluation attempts when lingering. A reevaluation could result 618 // in a transition to the validated state which would abort the linger 619 // timeout. Lingering is the result of score assessment; validity is 620 // irrelevant. 621 return HANDLED; 622 case CMD_CAPTIVE_PORTAL_APP_FINISHED: 623 // Ignore user network determination as this could abort linger timeout. 624 // Networks are only lingered once validated because: 625 // - Unvalidated networks are never lingered (see rematchNetworkAndRequests). 626 // - Once validated, a Network's validated bit is never cleared. 627 // Since networks are only lingered after being validated a user's 628 // determination will not change the death sentence that lingering entails: 629 // - If the user wants to use the network or bypasses the captive portal, 630 // the network's score will not be increased beyond its current value 631 // because it is already validated. Without a score increase there is no 632 // chance of reactivation (i.e. aborting linger timeout). 633 // - If the user does not want the network, lingering will disconnect the 634 // network anyhow. 635 return HANDLED; 636 default: 637 return NOT_HANDLED; 638 } 639 } 640 641 @Override 642 public void exit() { 643 mAlarmManager.cancel(mIntent); 644 mContext.unregisterReceiver(mBroadcastReceiver); 645 } 646 } 647 648 /** 649 * Do a URL fetch on a known server to see if we get the data we expect. 650 * Returns HTTP response code. 651 */ 652 private int isCaptivePortal() { 653 if (!mIsCaptivePortalCheckEnabled) return 204; 654 655 HttpURLConnection urlConnection = null; 656 int httpResponseCode = 599; 657 try { 658 URL url = new URL("http", mServer, "/generate_204"); 659 if (DBG) { 660 log("Checking " + url.toString() + " on " + 661 mNetworkAgentInfo.networkInfo.getExtraInfo()); 662 } 663 urlConnection = (HttpURLConnection) mNetworkAgentInfo.network.openConnection(url); 664 urlConnection.setInstanceFollowRedirects(false); 665 urlConnection.setConnectTimeout(SOCKET_TIMEOUT_MS); 666 urlConnection.setReadTimeout(SOCKET_TIMEOUT_MS); 667 urlConnection.setUseCaches(false); 668 669 // Time how long it takes to get a response to our request 670 long requestTimestamp = SystemClock.elapsedRealtime(); 671 672 urlConnection.getInputStream(); 673 674 // Time how long it takes to get a response to our request 675 long responseTimestamp = SystemClock.elapsedRealtime(); 676 677 httpResponseCode = urlConnection.getResponseCode(); 678 if (DBG) { 679 log("isCaptivePortal: ret=" + httpResponseCode + 680 " headers=" + urlConnection.getHeaderFields()); 681 } 682 // NOTE: We may want to consider an "HTTP/1.0 204" response to be a captive 683 // portal. The only example of this seen so far was a captive portal. For 684 // the time being go with prior behavior of assuming it's not a captive 685 // portal. If it is considered a captive portal, a different sign-in URL 686 // is needed (i.e. can't browse a 204). This could be the result of an HTTP 687 // proxy server. 688 689 // Consider 200 response with "Content-length=0" to not be a captive portal. 690 // There's no point in considering this a captive portal as the user cannot 691 // sign-in to an empty page. Probably the result of a broken transparent proxy. 692 // See http://b/9972012. 693 if (httpResponseCode == 200 && urlConnection.getContentLength() == 0) { 694 if (DBG) log("Empty 200 response interpreted as 204 response."); 695 httpResponseCode = 204; 696 } 697 698 sendNetworkConditionsBroadcast(true /* response received */, 699 httpResponseCode != 204 /* isCaptivePortal */, 700 requestTimestamp, responseTimestamp); 701 } catch (IOException e) { 702 if (DBG) log("Probably not a portal: exception " + e); 703 if (httpResponseCode == 599) { 704 // TODO: Ping gateway and DNS server and log results. 705 } 706 } finally { 707 if (urlConnection != null) { 708 urlConnection.disconnect(); 709 } 710 } 711 return httpResponseCode; 712 } 713 714 /** 715 * @param responseReceived - whether or not we received a valid HTTP response to our request. 716 * If false, isCaptivePortal and responseTimestampMs are ignored 717 * TODO: This should be moved to the transports. The latency could be passed to the transports 718 * along with the captive portal result. Currently the TYPE_MOBILE broadcasts appear unused so 719 * perhaps this could just be added to the WiFi transport only. 720 */ 721 private void sendNetworkConditionsBroadcast(boolean responseReceived, boolean isCaptivePortal, 722 long requestTimestampMs, long responseTimestampMs) { 723 if (Settings.Global.getInt(mContext.getContentResolver(), 724 Settings.Global.WIFI_SCAN_ALWAYS_AVAILABLE, 0) == 0) { 725 if (DBG) log("Don't send network conditions - lacking user consent."); 726 return; 727 } 728 729 if (systemReady == false) return; 730 731 Intent latencyBroadcast = new Intent(ACTION_NETWORK_CONDITIONS_MEASURED); 732 switch (mNetworkAgentInfo.networkInfo.getType()) { 733 case ConnectivityManager.TYPE_WIFI: 734 WifiInfo currentWifiInfo = mWifiManager.getConnectionInfo(); 735 if (currentWifiInfo != null) { 736 // NOTE: getSSID()'s behavior changed in API 17; before that, SSIDs were not 737 // surrounded by double quotation marks (thus violating the Javadoc), but this 738 // was changed to match the Javadoc in API 17. Since clients may have started 739 // sanitizing the output of this method since API 17 was released, we should 740 // not change it here as it would become impossible to tell whether the SSID is 741 // simply being surrounded by quotes due to the API, or whether those quotes 742 // are actually part of the SSID. 743 latencyBroadcast.putExtra(EXTRA_SSID, currentWifiInfo.getSSID()); 744 latencyBroadcast.putExtra(EXTRA_BSSID, currentWifiInfo.getBSSID()); 745 } else { 746 if (DBG) logw("network info is TYPE_WIFI but no ConnectionInfo found"); 747 return; 748 } 749 break; 750 case ConnectivityManager.TYPE_MOBILE: 751 latencyBroadcast.putExtra(EXTRA_NETWORK_TYPE, mTelephonyManager.getNetworkType()); 752 List<CellInfo> info = mTelephonyManager.getAllCellInfo(); 753 if (info == null) return; 754 int numRegisteredCellInfo = 0; 755 for (CellInfo cellInfo : info) { 756 if (cellInfo.isRegistered()) { 757 numRegisteredCellInfo++; 758 if (numRegisteredCellInfo > 1) { 759 if (DBG) log("more than one registered CellInfo. Can't " + 760 "tell which is active. Bailing."); 761 return; 762 } 763 if (cellInfo instanceof CellInfoCdma) { 764 CellIdentityCdma cellId = ((CellInfoCdma) cellInfo).getCellIdentity(); 765 latencyBroadcast.putExtra(EXTRA_CELL_ID, cellId); 766 } else if (cellInfo instanceof CellInfoGsm) { 767 CellIdentityGsm cellId = ((CellInfoGsm) cellInfo).getCellIdentity(); 768 latencyBroadcast.putExtra(EXTRA_CELL_ID, cellId); 769 } else if (cellInfo instanceof CellInfoLte) { 770 CellIdentityLte cellId = ((CellInfoLte) cellInfo).getCellIdentity(); 771 latencyBroadcast.putExtra(EXTRA_CELL_ID, cellId); 772 } else if (cellInfo instanceof CellInfoWcdma) { 773 CellIdentityWcdma cellId = ((CellInfoWcdma) cellInfo).getCellIdentity(); 774 latencyBroadcast.putExtra(EXTRA_CELL_ID, cellId); 775 } else { 776 if (DBG) logw("Registered cellinfo is unrecognized"); 777 return; 778 } 779 } 780 } 781 break; 782 default: 783 return; 784 } 785 latencyBroadcast.putExtra(EXTRA_CONNECTIVITY_TYPE, mNetworkAgentInfo.networkInfo.getType()); 786 latencyBroadcast.putExtra(EXTRA_RESPONSE_RECEIVED, responseReceived); 787 latencyBroadcast.putExtra(EXTRA_REQUEST_TIMESTAMP_MS, requestTimestampMs); 788 789 if (responseReceived) { 790 latencyBroadcast.putExtra(EXTRA_IS_CAPTIVE_PORTAL, isCaptivePortal); 791 latencyBroadcast.putExtra(EXTRA_RESPONSE_TIMESTAMP_MS, responseTimestampMs); 792 } 793 mContext.sendBroadcastAsUser(latencyBroadcast, UserHandle.CURRENT, 794 PERMISSION_ACCESS_NETWORK_CONDITIONS); 795 } 796} 797