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 17 package com.android.server.connectivity; 18 19 import android.app.AlarmManager; 20 import android.app.PendingIntent; 21 import android.content.BroadcastReceiver; 22 import android.content.ComponentName; 23 import android.content.Context; 24 import android.content.Intent; 25 import android.content.IntentFilter; 26 import android.net.ConnectivityManager; 27 import android.net.Network; 28 import android.net.NetworkCapabilities; 29 import android.net.NetworkInfo; 30 import android.net.NetworkRequest; 31 import android.net.ProxyInfo; 32 import android.net.TrafficStats; 33 import android.net.Uri; 34 import android.net.wifi.WifiInfo; 35 import android.net.wifi.WifiManager; 36 import android.os.Handler; 37 import android.os.Message; 38 import android.os.SystemClock; 39 import android.os.SystemProperties; 40 import android.os.UserHandle; 41 import android.provider.Settings; 42 import android.telephony.CellIdentityCdma; 43 import android.telephony.CellIdentityGsm; 44 import android.telephony.CellIdentityLte; 45 import android.telephony.CellIdentityWcdma; 46 import android.telephony.CellInfo; 47 import android.telephony.CellInfoCdma; 48 import android.telephony.CellInfoGsm; 49 import android.telephony.CellInfoLte; 50 import android.telephony.CellInfoWcdma; 51 import android.telephony.TelephonyManager; 52 import android.util.Log; 53 54 import com.android.internal.util.Protocol; 55 import com.android.internal.util.State; 56 import com.android.internal.util.StateMachine; 57 import com.android.server.ConnectivityService; 58 import com.android.server.connectivity.NetworkAgentInfo; 59 60 import java.io.IOException; 61 import java.net.HttpURLConnection; 62 import java.net.URL; 63 import java.util.List; 64 import java.util.Random; 65 66 /** 67 * {@hide} 68 */ 69 public class NetworkMonitor extends StateMachine { 70 private static final boolean DBG = true; 71 private static final String TAG = "NetworkMonitor"; 72 private static final String DEFAULT_SERVER = "connectivitycheck.android.com"; 73 private static final int SOCKET_TIMEOUT_MS = 10000; 74 public static final String ACTION_NETWORK_CONDITIONS_MEASURED = 75 "android.net.conn.NETWORK_CONDITIONS_MEASURED"; 76 public static final String EXTRA_CONNECTIVITY_TYPE = "extra_connectivity_type"; 77 public static final String EXTRA_NETWORK_TYPE = "extra_network_type"; 78 public static final String EXTRA_RESPONSE_RECEIVED = "extra_response_received"; 79 public static final String EXTRA_IS_CAPTIVE_PORTAL = "extra_is_captive_portal"; 80 public static final String EXTRA_CELL_ID = "extra_cellid"; 81 public static final String EXTRA_SSID = "extra_ssid"; 82 public static final String EXTRA_BSSID = "extra_bssid"; 83 /** real time since boot */ 84 public static final String EXTRA_REQUEST_TIMESTAMP_MS = "extra_request_timestamp_ms"; 85 public static final String EXTRA_RESPONSE_TIMESTAMP_MS = "extra_response_timestamp_ms"; 86 87 private static final String PERMISSION_ACCESS_NETWORK_CONDITIONS = 88 "android.permission.ACCESS_NETWORK_CONDITIONS"; 89 90 // Keep these in sync with CaptivePortalLoginActivity.java. 91 // Intent broadcast from CaptivePortalLogin indicating sign-in is complete. 92 // Extras: 93 // EXTRA_TEXT = netId 94 // LOGGED_IN_RESULT = one of the CAPTIVE_PORTAL_APP_RETURN_* values below. 95 // RESPONSE_TOKEN = data fragment from launching Intent 96 private static final String ACTION_CAPTIVE_PORTAL_LOGGED_IN = 97 "android.net.netmon.captive_portal_logged_in"; 98 private static final String LOGGED_IN_RESULT = "result"; 99 private static final String RESPONSE_TOKEN = "response_token"; 100 101 // After a network has been tested this result can be sent with EVENT_NETWORK_TESTED. 102 // The network should be used as a default internet connection. It was found to be: 103 // 1. a functioning network providing internet access, or 104 // 2. a captive portal and the user decided to use it as is. 105 public static final int NETWORK_TEST_RESULT_VALID = 0; 106 // After a network has been tested this result can be sent with EVENT_NETWORK_TESTED. 107 // The network should not be used as a default internet connection. It was found to be: 108 // 1. a captive portal and the user is prompted to sign-in, or 109 // 2. a captive portal and the user did not want to use it, or 110 // 3. a broken network (e.g. DNS failed, connect failed, HTTP request failed). 111 public static final int NETWORK_TEST_RESULT_INVALID = 1; 112 113 private static final int BASE = Protocol.BASE_NETWORK_MONITOR; 114 115 /** 116 * Inform NetworkMonitor that their network is connected. 117 * Initiates Network Validation. 118 */ 119 public static final int CMD_NETWORK_CONNECTED = BASE + 1; 120 121 /** 122 * Inform ConnectivityService that the network has been tested. 123 * obj = NetworkAgentInfo 124 * arg1 = One of the NETWORK_TESTED_RESULT_* constants. 125 */ 126 public static final int EVENT_NETWORK_TESTED = BASE + 2; 127 128 /** 129 * Inform NetworkMonitor to linger a network. The Monitor should 130 * start a timer and/or start watching for zero live connections while 131 * moving towards LINGER_COMPLETE. After the Linger period expires 132 * (or other events mark the end of the linger state) the LINGER_COMPLETE 133 * event should be sent and the network will be shut down. If a 134 * CMD_NETWORK_CONNECTED happens before the LINGER completes 135 * it indicates further desire to keep the network alive and so 136 * the LINGER is aborted. 137 */ 138 public static final int CMD_NETWORK_LINGER = BASE + 3; 139 140 /** 141 * Message to self indicating linger delay has expired. 142 * arg1 = Token to ignore old messages. 143 */ 144 private static final int CMD_LINGER_EXPIRED = BASE + 4; 145 146 /** 147 * Inform ConnectivityService that the network LINGER period has 148 * expired. 149 * obj = NetworkAgentInfo 150 */ 151 public static final int EVENT_NETWORK_LINGER_COMPLETE = BASE + 5; 152 153 /** 154 * Message to self indicating it's time to evaluate a network's connectivity. 155 * arg1 = Token to ignore old messages. 156 */ 157 private static final int CMD_REEVALUATE = BASE + 6; 158 159 /** 160 * Inform NetworkMonitor that the network has disconnected. 161 */ 162 public static final int CMD_NETWORK_DISCONNECTED = BASE + 7; 163 164 /** 165 * Force evaluation even if it has succeeded in the past. 166 * arg1 = UID responsible for requesting this reeval. Will be billed for data. 167 * arg2 = Number of evaluation attempts to make. (If 0, make INITIAL_ATTEMPTS attempts.) 168 */ 169 public static final int CMD_FORCE_REEVALUATION = BASE + 8; 170 171 /** 172 * Message to self indicating captive portal app finished. 173 * arg1 = one of: CAPTIVE_PORTAL_APP_RETURN_APPEASED, 174 * CAPTIVE_PORTAL_APP_RETURN_UNWANTED, 175 * CAPTIVE_PORTAL_APP_RETURN_WANTED_AS_IS 176 */ 177 private static final int CMD_CAPTIVE_PORTAL_APP_FINISHED = BASE + 9; 178 179 /** 180 * Request ConnectivityService display provisioning notification. 181 * arg1 = Whether to make the notification visible. 182 * arg2 = NetID. 183 * obj = Intent to be launched when notification selected by user, null if !arg1. 184 */ 185 public static final int EVENT_PROVISIONING_NOTIFICATION = BASE + 10; 186 187 /** 188 * Message to self indicating sign-in app bypassed captive portal. 189 */ 190 private static final int EVENT_APP_BYPASSED_CAPTIVE_PORTAL = BASE + 11; 191 192 /** 193 * Message to self indicating no sign-in app responded. 194 */ 195 private static final int EVENT_NO_APP_RESPONSE = BASE + 12; 196 197 /** 198 * Message to self indicating sign-in app indicates sign-in is not possible. 199 */ 200 private static final int EVENT_APP_INDICATES_SIGN_IN_IMPOSSIBLE = BASE + 13; 201 202 /** 203 * Return codes from captive portal sign-in app. 204 */ 205 public static final int CAPTIVE_PORTAL_APP_RETURN_APPEASED = 0; 206 public static final int CAPTIVE_PORTAL_APP_RETURN_UNWANTED = 1; 207 public static final int CAPTIVE_PORTAL_APP_RETURN_WANTED_AS_IS = 2; 208 209 private static final String LINGER_DELAY_PROPERTY = "persist.netmon.linger"; 210 // Default to 30s linger time-out. 211 private static final int DEFAULT_LINGER_DELAY_MS = 30000; 212 private final int mLingerDelayMs; 213 private int mLingerToken = 0; 214 215 // Negative values disable reevaluation. 216 private static final String REEVALUATE_DELAY_PROPERTY = "persist.netmon.reeval_delay"; 217 // When connecting, attempt to validate 3 times, pausing 5s between them. 218 private static final int DEFAULT_REEVALUATE_DELAY_MS = 5000; 219 private static final int INITIAL_ATTEMPTS = 3; 220 // If a network is not validated, make one attempt every 10 mins to see if it starts working. 221 private static final int REEVALUATE_PAUSE_MS = 10*60*1000; 222 private static final int PERIODIC_ATTEMPTS = 1; 223 // When an application calls reportBadNetwork, only make one attempt. 224 private static final int REEVALUATE_ATTEMPTS = 1; 225 private final int mReevaluateDelayMs; 226 private int mReevaluateToken = 0; 227 private static final int INVALID_UID = -1; 228 private int mUidResponsibleForReeval = INVALID_UID; 229 230 private final Context mContext; 231 private final Handler mConnectivityServiceHandler; 232 private final NetworkAgentInfo mNetworkAgentInfo; 233 private final TelephonyManager mTelephonyManager; 234 private final WifiManager mWifiManager; 235 private final AlarmManager mAlarmManager; 236 private final NetworkRequest mDefaultRequest; 237 238 private String mServer; 239 private boolean mIsCaptivePortalCheckEnabled = false; 240 241 // Set if the user explicitly selected "Do not use this network" in captive portal sign-in app. 242 private boolean mUserDoesNotWant = false; 243 244 // How many times we should attempt validation. Only checked in EvaluatingState; must be set 245 // before entering EvaluatingState. Note that whatever code causes us to transition to 246 // EvaluatingState last decides how many attempts will be made, so if one codepath were to 247 // enter EvaluatingState with a specific number of attempts, and then another were to enter it 248 // with a different number of attempts, the second number would be used. This is not currently 249 // a problem because EvaluatingState is not reentrant. 250 private int mMaxAttempts; 251 252 public boolean systemReady = false; 253 254 private final State mDefaultState = new DefaultState(); 255 private final State mOfflineState = new OfflineState(); 256 private final State mValidatedState = new ValidatedState(); 257 private final State mMaybeNotifyState = new MaybeNotifyState(); 258 private final State mEvaluatingState = new EvaluatingState(); 259 private final State mCaptivePortalState = new CaptivePortalState(); 260 private final State mLingeringState = new LingeringState(); 261 262 private CaptivePortalLoggedInBroadcastReceiver mCaptivePortalLoggedInBroadcastReceiver = null; 263 private String mCaptivePortalLoggedInResponseToken = null; 264 265 public NetworkMonitor(Context context, Handler handler, NetworkAgentInfo networkAgentInfo, 266 NetworkRequest defaultRequest) { 267 // Add suffix indicating which NetworkMonitor we're talking about. 268 super(TAG + networkAgentInfo.name()); 269 270 mContext = context; 271 mConnectivityServiceHandler = handler; 272 mNetworkAgentInfo = networkAgentInfo; 273 mTelephonyManager = (TelephonyManager) context.getSystemService(Context.TELEPHONY_SERVICE); 274 mWifiManager = (WifiManager) context.getSystemService(Context.WIFI_SERVICE); 275 mAlarmManager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE); 276 mDefaultRequest = defaultRequest; 277 278 addState(mDefaultState); 279 addState(mOfflineState, mDefaultState); 280 addState(mValidatedState, mDefaultState); 281 addState(mMaybeNotifyState, mDefaultState); 282 addState(mEvaluatingState, mMaybeNotifyState); 283 addState(mCaptivePortalState, mMaybeNotifyState); 284 addState(mLingeringState, mDefaultState); 285 setInitialState(mDefaultState); 286 287 mServer = Settings.Global.getString(mContext.getContentResolver(), 288 Settings.Global.CAPTIVE_PORTAL_SERVER); 289 if (mServer == null) mServer = DEFAULT_SERVER; 290 291 mLingerDelayMs = SystemProperties.getInt(LINGER_DELAY_PROPERTY, DEFAULT_LINGER_DELAY_MS); 292 mReevaluateDelayMs = SystemProperties.getInt(REEVALUATE_DELAY_PROPERTY, 293 DEFAULT_REEVALUATE_DELAY_MS); 294 295 mIsCaptivePortalCheckEnabled = Settings.Global.getInt(mContext.getContentResolver(), 296 Settings.Global.CAPTIVE_PORTAL_DETECTION_ENABLED, 1) == 1; 297 298 mCaptivePortalLoggedInResponseToken = String.valueOf(new Random().nextLong()); 299 300 start(); 301 } 302 303 @Override 304 protected void log(String s) { 305 Log.d(TAG + "/" + mNetworkAgentInfo.name(), s); 306 } 307 308 // DefaultState is the parent of all States. It exists only to handle CMD_* messages but 309 // does not entail any real state (hence no enter() or exit() routines). 310 private class DefaultState extends State { 311 @Override 312 public boolean processMessage(Message message) { 313 if (DBG) log(getName() + message.toString()); 314 switch (message.what) { 315 case CMD_NETWORK_LINGER: 316 if (DBG) log("Lingering"); 317 transitionTo(mLingeringState); 318 return HANDLED; 319 case CMD_NETWORK_CONNECTED: 320 if (DBG) log("Connected"); 321 mMaxAttempts = INITIAL_ATTEMPTS; 322 transitionTo(mEvaluatingState); 323 return HANDLED; 324 case CMD_NETWORK_DISCONNECTED: 325 if (DBG) log("Disconnected - quitting"); 326 if (mCaptivePortalLoggedInBroadcastReceiver != null) { 327 mContext.unregisterReceiver(mCaptivePortalLoggedInBroadcastReceiver); 328 mCaptivePortalLoggedInBroadcastReceiver = null; 329 } 330 quit(); 331 return HANDLED; 332 case CMD_FORCE_REEVALUATION: 333 if (DBG) log("Forcing reevaluation"); 334 mUidResponsibleForReeval = message.arg1; 335 mMaxAttempts = message.arg2 != 0 ? message.arg2 : REEVALUATE_ATTEMPTS; 336 transitionTo(mEvaluatingState); 337 return HANDLED; 338 case CMD_CAPTIVE_PORTAL_APP_FINISHED: 339 // Previous token was broadcast, come up with a new one. 340 mCaptivePortalLoggedInResponseToken = String.valueOf(new Random().nextLong()); 341 switch (message.arg1) { 342 case CAPTIVE_PORTAL_APP_RETURN_APPEASED: 343 case CAPTIVE_PORTAL_APP_RETURN_WANTED_AS_IS: 344 transitionTo(mValidatedState); 345 break; 346 case CAPTIVE_PORTAL_APP_RETURN_UNWANTED: 347 mUserDoesNotWant = true; 348 // TODO: Should teardown network. 349 transitionTo(mOfflineState); 350 break; 351 } 352 return HANDLED; 353 default: 354 return HANDLED; 355 } 356 } 357 } 358 359 // Being in the OfflineState State indicates a Network is unwanted or failed validation. 360 private class OfflineState extends State { 361 @Override 362 public void enter() { 363 mConnectivityServiceHandler.sendMessage(obtainMessage(EVENT_NETWORK_TESTED, 364 NETWORK_TEST_RESULT_INVALID, 0, mNetworkAgentInfo)); 365 if (!mUserDoesNotWant) { 366 sendMessageDelayed(CMD_FORCE_REEVALUATION, 0 /* no UID */, 367 PERIODIC_ATTEMPTS, REEVALUATE_PAUSE_MS); 368 } 369 } 370 371 @Override 372 public boolean processMessage(Message message) { 373 if (DBG) log(getName() + message.toString()); 374 switch (message.what) { 375 case CMD_FORCE_REEVALUATION: 376 // If the user has indicated they explicitly do not want to use this network, 377 // don't allow a reevaluation as this will be pointless and could result in 378 // the user being annoyed with repeated unwanted notifications. 379 return mUserDoesNotWant ? HANDLED : NOT_HANDLED; 380 default: 381 return NOT_HANDLED; 382 } 383 } 384 385 @Override 386 public void exit() { 387 // NOTE: This removes the delayed message posted by enter() but will inadvertently 388 // remove any other CMD_FORCE_REEVALUATION in the message queue. At the moment this 389 // is harmless. If in the future this becomes problematic a different message could 390 // be used. 391 removeMessages(CMD_FORCE_REEVALUATION); 392 } 393 } 394 395 // Being in the ValidatedState State indicates a Network is: 396 // - Successfully validated, or 397 // - Wanted "as is" by the user, or 398 // - Does not satsify the default NetworkRequest and so validation has been skipped. 399 private class ValidatedState extends State { 400 @Override 401 public void enter() { 402 if (DBG) log("Validated"); 403 mConnectivityServiceHandler.sendMessage(obtainMessage(EVENT_NETWORK_TESTED, 404 NETWORK_TEST_RESULT_VALID, 0, mNetworkAgentInfo)); 405 } 406 407 @Override 408 public boolean processMessage(Message message) { 409 if (DBG) log(getName() + message.toString()); 410 switch (message.what) { 411 case CMD_NETWORK_CONNECTED: 412 transitionTo(mValidatedState); 413 return HANDLED; 414 default: 415 return NOT_HANDLED; 416 } 417 } 418 } 419 420 // Being in the MaybeNotifyState State indicates the user may have been notified that sign-in 421 // is required. This State takes care to clear the notification upon exit from the State. 422 private class MaybeNotifyState extends State { 423 @Override 424 public void exit() { 425 Message message = obtainMessage(EVENT_PROVISIONING_NOTIFICATION, 0, 426 mNetworkAgentInfo.network.netId, null); 427 mConnectivityServiceHandler.sendMessage(message); 428 } 429 } 430 431 // Being in the EvaluatingState State indicates the Network is being evaluated for internet 432 // connectivity. 433 private class EvaluatingState extends State { 434 private int mAttempt; 435 436 @Override 437 public void enter() { 438 mAttempt = 1; 439 sendMessage(CMD_REEVALUATE, ++mReevaluateToken, 0); 440 if (mUidResponsibleForReeval != INVALID_UID) { 441 TrafficStats.setThreadStatsUid(mUidResponsibleForReeval); 442 mUidResponsibleForReeval = INVALID_UID; 443 } 444 } 445 446 @Override 447 public boolean processMessage(Message message) { 448 if (DBG) log(getName() + message.toString()); 449 switch (message.what) { 450 case CMD_REEVALUATE: 451 if (message.arg1 != mReevaluateToken) 452 return HANDLED; 453 // Don't bother validating networks that don't satisify the default request. 454 // This includes: 455 // - VPNs which can be considered explicitly desired by the user and the 456 // user's desire trumps whether the network validates. 457 // - Networks that don't provide internet access. It's unclear how to 458 // validate such networks. 459 // - Untrusted networks. It's unsafe to prompt the user to sign-in to 460 // such networks and the user didn't express interest in connecting to 461 // such networks (an app did) so the user may be unhappily surprised when 462 // asked to sign-in to a network they didn't want to connect to in the 463 // first place. Validation could be done to adjust the network scores 464 // however these networks are app-requested and may not be intended for 465 // general usage, in which case general validation may not be an accurate 466 // measure of the network's quality. Only the app knows how to evaluate 467 // the network so don't bother validating here. Furthermore sending HTTP 468 // packets over the network may be undesirable, for example an extremely 469 // expensive metered network, or unwanted leaking of the User Agent string. 470 if (!mDefaultRequest.networkCapabilities.satisfiedByNetworkCapabilities( 471 mNetworkAgentInfo.networkCapabilities)) { 472 transitionTo(mValidatedState); 473 return HANDLED; 474 } 475 // Note: This call to isCaptivePortal() could take up to a minute. Resolving the 476 // server's IP addresses could hit the DNS timeout, and attempting connections 477 // to each of the server's several IP addresses (currently one IPv4 and one 478 // IPv6) could each take SOCKET_TIMEOUT_MS. During this time this StateMachine 479 // will be unresponsive. isCaptivePortal() could be executed on another Thread 480 // if this is found to cause problems. 481 int httpResponseCode = isCaptivePortal(); 482 if (httpResponseCode == 204) { 483 transitionTo(mValidatedState); 484 } else if (httpResponseCode >= 200 && httpResponseCode <= 399) { 485 transitionTo(mCaptivePortalState); 486 } else if (++mAttempt > mMaxAttempts) { 487 transitionTo(mOfflineState); 488 } else if (mReevaluateDelayMs >= 0) { 489 Message msg = obtainMessage(CMD_REEVALUATE, ++mReevaluateToken, 0); 490 sendMessageDelayed(msg, mReevaluateDelayMs); 491 } 492 return HANDLED; 493 case CMD_FORCE_REEVALUATION: 494 // Ignore duplicate requests. 495 return HANDLED; 496 default: 497 return NOT_HANDLED; 498 } 499 } 500 501 @Override 502 public void exit() { 503 TrafficStats.clearThreadStatsUid(); 504 } 505 } 506 507 // BroadcastReceiver that waits for a particular Intent and then posts a message. 508 private class CustomIntentReceiver extends BroadcastReceiver { 509 private final int mToken; 510 private final int mWhat; 511 private final String mAction; 512 CustomIntentReceiver(String action, int token, int what) { 513 mToken = token; 514 mWhat = what; 515 mAction = action + "_" + mNetworkAgentInfo.network.netId + "_" + token; 516 mContext.registerReceiver(this, new IntentFilter(mAction)); 517 } 518 public PendingIntent getPendingIntent() { 519 return PendingIntent.getBroadcast(mContext, 0, new Intent(mAction), 0); 520 } 521 @Override 522 public void onReceive(Context context, Intent intent) { 523 if (intent.getAction().equals(mAction)) sendMessage(obtainMessage(mWhat, mToken)); 524 } 525 } 526 527 private class CaptivePortalLoggedInBroadcastReceiver extends BroadcastReceiver { 528 @Override 529 public void onReceive(Context context, Intent intent) { 530 if (Integer.parseInt(intent.getStringExtra(Intent.EXTRA_TEXT)) == 531 mNetworkAgentInfo.network.netId && 532 mCaptivePortalLoggedInResponseToken.equals( 533 intent.getStringExtra(RESPONSE_TOKEN))) { 534 sendMessage(obtainMessage(CMD_CAPTIVE_PORTAL_APP_FINISHED, 535 Integer.parseInt(intent.getStringExtra(LOGGED_IN_RESULT)), 0)); 536 } 537 } 538 } 539 540 // Being in the CaptivePortalState State indicates a captive portal was detected and the user 541 // has been shown a notification to sign-in. 542 private class CaptivePortalState extends State { 543 @Override 544 public void enter() { 545 mConnectivityServiceHandler.sendMessage(obtainMessage(EVENT_NETWORK_TESTED, 546 NETWORK_TEST_RESULT_INVALID, 0, mNetworkAgentInfo)); 547 548 // Assemble Intent to launch captive portal sign-in app. 549 final Intent intent = new Intent(Intent.ACTION_SEND); 550 // Intent cannot use extras because PendingIntent.getActivity will merge matching 551 // Intents erasing extras. Use data instead of extras to encode NetID. 552 intent.setData(Uri.fromParts("netid", Integer.toString(mNetworkAgentInfo.network.netId), 553 mCaptivePortalLoggedInResponseToken)); 554 intent.setComponent(new ComponentName("com.android.captiveportallogin", 555 "com.android.captiveportallogin.CaptivePortalLoginActivity")); 556 intent.setFlags(Intent.FLAG_ACTIVITY_BROUGHT_TO_FRONT | Intent.FLAG_ACTIVITY_NEW_TASK); 557 558 if (mCaptivePortalLoggedInBroadcastReceiver == null) { 559 // Wait for result. 560 mCaptivePortalLoggedInBroadcastReceiver = 561 new CaptivePortalLoggedInBroadcastReceiver(); 562 final IntentFilter filter = new IntentFilter(ACTION_CAPTIVE_PORTAL_LOGGED_IN); 563 mContext.registerReceiver(mCaptivePortalLoggedInBroadcastReceiver, filter); 564 } 565 // Initiate notification to sign-in. 566 Message message = obtainMessage(EVENT_PROVISIONING_NOTIFICATION, 1, 567 mNetworkAgentInfo.network.netId, 568 PendingIntent.getActivity(mContext, 0, intent, 0)); 569 mConnectivityServiceHandler.sendMessage(message); 570 } 571 572 @Override 573 public boolean processMessage(Message message) { 574 if (DBG) log(getName() + message.toString()); 575 return NOT_HANDLED; 576 } 577 } 578 579 // Being in the LingeringState State indicates a Network's validated bit is true and it once 580 // was the highest scoring Network satisfying a particular NetworkRequest, but since then 581 // another Network satsified the NetworkRequest with a higher score and hence this Network 582 // is "lingered" for a fixed period of time before it is disconnected. This period of time 583 // allows apps to wrap up communication and allows for seamless reactivation if the other 584 // higher scoring Network happens to disconnect. 585 private class LingeringState extends State { 586 private static final String ACTION_LINGER_EXPIRED = "android.net.netmon.lingerExpired"; 587 588 private CustomIntentReceiver mBroadcastReceiver; 589 private PendingIntent mIntent; 590 591 @Override 592 public void enter() { 593 mLingerToken = new Random().nextInt(); 594 mBroadcastReceiver = new CustomIntentReceiver(ACTION_LINGER_EXPIRED, mLingerToken, 595 CMD_LINGER_EXPIRED); 596 mIntent = mBroadcastReceiver.getPendingIntent(); 597 long wakeupTime = SystemClock.elapsedRealtime() + mLingerDelayMs; 598 mAlarmManager.setWindow(AlarmManager.ELAPSED_REALTIME_WAKEUP, wakeupTime, 599 // Give a specific window so we aren't subject to unknown inexactitude. 600 mLingerDelayMs / 6, mIntent); 601 } 602 603 @Override 604 public boolean processMessage(Message message) { 605 if (DBG) log(getName() + message.toString()); 606 switch (message.what) { 607 case CMD_NETWORK_CONNECTED: 608 // Go straight to active as we've already evaluated. 609 transitionTo(mValidatedState); 610 return HANDLED; 611 case CMD_LINGER_EXPIRED: 612 if (message.arg1 != mLingerToken) 613 return HANDLED; 614 mConnectivityServiceHandler.sendMessage( 615 obtainMessage(EVENT_NETWORK_LINGER_COMPLETE, mNetworkAgentInfo)); 616 return HANDLED; 617 case CMD_FORCE_REEVALUATION: 618 // Ignore reevaluation attempts when lingering. A reevaluation could result 619 // in a transition to the validated state which would abort the linger 620 // timeout. Lingering is the result of score assessment; validity is 621 // irrelevant. 622 return HANDLED; 623 case CMD_CAPTIVE_PORTAL_APP_FINISHED: 624 // Ignore user network determination as this could abort linger timeout. 625 // Networks are only lingered once validated because: 626 // - Unvalidated networks are never lingered (see rematchNetworkAndRequests). 627 // - Once validated, a Network's validated bit is never cleared. 628 // Since networks are only lingered after being validated a user's 629 // determination will not change the death sentence that lingering entails: 630 // - If the user wants to use the network or bypasses the captive portal, 631 // the network's score will not be increased beyond its current value 632 // because it is already validated. Without a score increase there is no 633 // chance of reactivation (i.e. aborting linger timeout). 634 // - If the user does not want the network, lingering will disconnect the 635 // network anyhow. 636 return HANDLED; 637 default: 638 return NOT_HANDLED; 639 } 640 } 641 642 @Override 643 public void exit() { 644 mAlarmManager.cancel(mIntent); 645 mContext.unregisterReceiver(mBroadcastReceiver); 646 } 647 } 648 649 /** 650 * Do a URL fetch on a known server to see if we get the data we expect. 651 * Returns HTTP response code. 652 */ 653 private int isCaptivePortal() { 654 if (!mIsCaptivePortalCheckEnabled) return 204; 655 656 HttpURLConnection urlConnection = null; 657 int httpResponseCode = 599; 658 try { 659 URL url = new URL("http", mServer, "/generate_204"); 660 // On networks with a PAC instead of fetching a URL that should result in a 204 661 // reponse, we instead simply fetch the PAC script. This is done for a few reasons: 662 // 1. At present our PAC code does not yet handle multiple PACs on multiple networks 663 // until something like https://android-review.googlesource.com/#/c/115180/ lands. 664 // Network.openConnection() will ignore network-specific PACs and instead fetch 665 // using NO_PROXY. If a PAC is in place, the only fetch we know will succeed with 666 // NO_PROXY is the fetch of the PAC itself. 667 // 2. To proxy the generate_204 fetch through a PAC would require a number of things 668 // happen before the fetch can commence, namely: 669 // a) the PAC script be fetched 670 // b) a PAC script resolver service be fired up and resolve mServer 671 // Network validation could be delayed until these prerequisities are satisifed or 672 // could simply be left to race them. Neither is an optimal solution. 673 // 3. PAC scripts are sometimes used to block or restrict Internet access and may in 674 // fact block fetching of the generate_204 URL which would lead to false negative 675 // results for network validation. 676 boolean fetchPac = false; 677 { 678 final ProxyInfo proxyInfo = mNetworkAgentInfo.linkProperties.getHttpProxy(); 679 if (proxyInfo != null && !Uri.EMPTY.equals(proxyInfo.getPacFileUrl())) { 680 url = new URL(proxyInfo.getPacFileUrl().toString()); 681 fetchPac = true; 682 } 683 } 684 if (DBG) { 685 log("Checking " + url.toString() + " on " + 686 mNetworkAgentInfo.networkInfo.getExtraInfo()); 687 } 688 urlConnection = (HttpURLConnection) mNetworkAgentInfo.network.openConnection(url); 689 urlConnection.setInstanceFollowRedirects(fetchPac); 690 urlConnection.setConnectTimeout(SOCKET_TIMEOUT_MS); 691 urlConnection.setReadTimeout(SOCKET_TIMEOUT_MS); 692 urlConnection.setUseCaches(false); 693 694 // Time how long it takes to get a response to our request 695 long requestTimestamp = SystemClock.elapsedRealtime(); 696 697 urlConnection.getInputStream(); 698 699 // Time how long it takes to get a response to our request 700 long responseTimestamp = SystemClock.elapsedRealtime(); 701 702 httpResponseCode = urlConnection.getResponseCode(); 703 if (DBG) { 704 log("isCaptivePortal: ret=" + httpResponseCode + 705 " headers=" + urlConnection.getHeaderFields()); 706 } 707 // NOTE: We may want to consider an "HTTP/1.0 204" response to be a captive 708 // portal. The only example of this seen so far was a captive portal. For 709 // the time being go with prior behavior of assuming it's not a captive 710 // portal. If it is considered a captive portal, a different sign-in URL 711 // is needed (i.e. can't browse a 204). This could be the result of an HTTP 712 // proxy server. 713 714 // Consider 200 response with "Content-length=0" to not be a captive portal. 715 // There's no point in considering this a captive portal as the user cannot 716 // sign-in to an empty page. Probably the result of a broken transparent proxy. 717 // See http://b/9972012. 718 if (httpResponseCode == 200 && urlConnection.getContentLength() == 0) { 719 if (DBG) log("Empty 200 response interpreted as 204 response."); 720 httpResponseCode = 204; 721 } 722 723 if (httpResponseCode == 200 && fetchPac) { 724 if (DBG) log("PAC fetch 200 response interpreted as 204 response."); 725 httpResponseCode = 204; 726 } 727 728 sendNetworkConditionsBroadcast(true /* response received */, 729 httpResponseCode != 204 /* isCaptivePortal */, 730 requestTimestamp, responseTimestamp); 731 } catch (IOException e) { 732 if (DBG) log("Probably not a portal: exception " + e); 733 if (httpResponseCode == 599) { 734 // TODO: Ping gateway and DNS server and log results. 735 } 736 } finally { 737 if (urlConnection != null) { 738 urlConnection.disconnect(); 739 } 740 } 741 return httpResponseCode; 742 } 743 744 /** 745 * @param responseReceived - whether or not we received a valid HTTP response to our request. 746 * If false, isCaptivePortal and responseTimestampMs are ignored 747 * TODO: This should be moved to the transports. The latency could be passed to the transports 748 * along with the captive portal result. Currently the TYPE_MOBILE broadcasts appear unused so 749 * perhaps this could just be added to the WiFi transport only. 750 */ 751 private void sendNetworkConditionsBroadcast(boolean responseReceived, boolean isCaptivePortal, 752 long requestTimestampMs, long responseTimestampMs) { 753 if (Settings.Global.getInt(mContext.getContentResolver(), 754 Settings.Global.WIFI_SCAN_ALWAYS_AVAILABLE, 0) == 0) { 755 if (DBG) log("Don't send network conditions - lacking user consent."); 756 return; 757 } 758 759 if (systemReady == false) return; 760 761 Intent latencyBroadcast = new Intent(ACTION_NETWORK_CONDITIONS_MEASURED); 762 switch (mNetworkAgentInfo.networkInfo.getType()) { 763 case ConnectivityManager.TYPE_WIFI: 764 WifiInfo currentWifiInfo = mWifiManager.getConnectionInfo(); 765 if (currentWifiInfo != null) { 766 // NOTE: getSSID()'s behavior changed in API 17; before that, SSIDs were not 767 // surrounded by double quotation marks (thus violating the Javadoc), but this 768 // was changed to match the Javadoc in API 17. Since clients may have started 769 // sanitizing the output of this method since API 17 was released, we should 770 // not change it here as it would become impossible to tell whether the SSID is 771 // simply being surrounded by quotes due to the API, or whether those quotes 772 // are actually part of the SSID. 773 latencyBroadcast.putExtra(EXTRA_SSID, currentWifiInfo.getSSID()); 774 latencyBroadcast.putExtra(EXTRA_BSSID, currentWifiInfo.getBSSID()); 775 } else { 776 if (DBG) logw("network info is TYPE_WIFI but no ConnectionInfo found"); 777 return; 778 } 779 break; 780 case ConnectivityManager.TYPE_MOBILE: 781 latencyBroadcast.putExtra(EXTRA_NETWORK_TYPE, mTelephonyManager.getNetworkType()); 782 List<CellInfo> info = mTelephonyManager.getAllCellInfo(); 783 if (info == null) return; 784 int numRegisteredCellInfo = 0; 785 for (CellInfo cellInfo : info) { 786 if (cellInfo.isRegistered()) { 787 numRegisteredCellInfo++; 788 if (numRegisteredCellInfo > 1) { 789 if (DBG) log("more than one registered CellInfo. Can't " + 790 "tell which is active. Bailing."); 791 return; 792 } 793 if (cellInfo instanceof CellInfoCdma) { 794 CellIdentityCdma cellId = ((CellInfoCdma) cellInfo).getCellIdentity(); 795 latencyBroadcast.putExtra(EXTRA_CELL_ID, cellId); 796 } else if (cellInfo instanceof CellInfoGsm) { 797 CellIdentityGsm cellId = ((CellInfoGsm) cellInfo).getCellIdentity(); 798 latencyBroadcast.putExtra(EXTRA_CELL_ID, cellId); 799 } else if (cellInfo instanceof CellInfoLte) { 800 CellIdentityLte cellId = ((CellInfoLte) cellInfo).getCellIdentity(); 801 latencyBroadcast.putExtra(EXTRA_CELL_ID, cellId); 802 } else if (cellInfo instanceof CellInfoWcdma) { 803 CellIdentityWcdma cellId = ((CellInfoWcdma) cellInfo).getCellIdentity(); 804 latencyBroadcast.putExtra(EXTRA_CELL_ID, cellId); 805 } else { 806 if (DBG) logw("Registered cellinfo is unrecognized"); 807 return; 808 } 809 } 810 } 811 break; 812 default: 813 return; 814 } 815 latencyBroadcast.putExtra(EXTRA_CONNECTIVITY_TYPE, mNetworkAgentInfo.networkInfo.getType()); 816 latencyBroadcast.putExtra(EXTRA_RESPONSE_RECEIVED, responseReceived); 817 latencyBroadcast.putExtra(EXTRA_REQUEST_TIMESTAMP_MS, requestTimestampMs); 818 819 if (responseReceived) { 820 latencyBroadcast.putExtra(EXTRA_IS_CAPTIVE_PORTAL, isCaptivePortal); 821 latencyBroadcast.putExtra(EXTRA_RESPONSE_TIMESTAMP_MS, responseTimestampMs); 822 } 823 mContext.sendBroadcastAsUser(latencyBroadcast, UserHandle.CURRENT, 824 PERMISSION_ACCESS_NETWORK_CONDITIONS); 825 } 826 } 827
