1 /*
2  * Copyright (C) 2015 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 package com.android.settingslib.wifi;
17 
18 import android.annotation.AnyThread;
19 import android.annotation.MainThread;
20 import android.content.BroadcastReceiver;
21 import android.content.Context;
22 import android.content.Intent;
23 import android.content.IntentFilter;
24 import android.net.ConnectivityManager;
25 import android.net.Network;
26 import android.net.NetworkCapabilities;
27 import android.net.NetworkInfo;
28 import android.net.NetworkKey;
29 import android.net.NetworkRequest;
30 import android.net.NetworkScoreManager;
31 import android.net.ScoredNetwork;
32 import android.net.wifi.ScanResult;
33 import android.net.wifi.WifiConfiguration;
34 import android.net.wifi.WifiInfo;
35 import android.net.wifi.WifiManager;
36 import android.net.wifi.WifiNetworkScoreCache;
37 import android.net.wifi.WifiNetworkScoreCache.CacheListener;
38 import android.net.wifi.hotspot2.OsuProvider;
39 import android.os.Handler;
40 import android.os.HandlerThread;
41 import android.os.Message;
42 import android.os.Process;
43 import android.os.SystemClock;
44 import android.provider.Settings;
45 import android.text.format.DateUtils;
46 import android.util.ArrayMap;
47 import android.util.ArraySet;
48 import android.util.Log;
49 import android.util.Pair;
50 import android.widget.Toast;
51 
52 import androidx.annotation.GuardedBy;
53 import androidx.annotation.NonNull;
54 import androidx.annotation.VisibleForTesting;
55 
56 import com.android.settingslib.R;
57 import com.android.settingslib.core.lifecycle.Lifecycle;
58 import com.android.settingslib.core.lifecycle.LifecycleObserver;
59 import com.android.settingslib.core.lifecycle.events.OnDestroy;
60 import com.android.settingslib.core.lifecycle.events.OnStart;
61 import com.android.settingslib.core.lifecycle.events.OnStop;
62 import com.android.settingslib.utils.ThreadUtils;
63 
64 import java.io.PrintWriter;
65 import java.util.ArrayList;
66 import java.util.Collection;
67 import java.util.Collections;
68 import java.util.HashMap;
69 import java.util.Iterator;
70 import java.util.List;
71 import java.util.ListIterator;
72 import java.util.Map;
73 import java.util.Set;
74 import java.util.concurrent.atomic.AtomicBoolean;
75 
76 /**
77  * Tracks saved or available wifi networks and their state.
78  */
79 public class WifiTracker implements LifecycleObserver, OnStart, OnStop, OnDestroy {
80     /**
81      * Default maximum age in millis of cached scored networks in
82      * {@link AccessPoint#mScoredNetworkCache} to be used for speed label generation.
83      */
84     private static final long DEFAULT_MAX_CACHED_SCORE_AGE_MILLIS = 20 * DateUtils.MINUTE_IN_MILLIS;
85 
86     /** Maximum age of scan results to hold onto while actively scanning. **/
87     @VisibleForTesting static final long MAX_SCAN_RESULT_AGE_MILLIS = 15000;
88 
89     private static final String TAG = "WifiTracker";
DBG()90     private static final boolean DBG() {
91         return Log.isLoggable(TAG, Log.DEBUG);
92     }
93 
isVerboseLoggingEnabled()94     private static boolean isVerboseLoggingEnabled() {
95         return WifiTracker.sVerboseLogging || Log.isLoggable(TAG, Log.VERBOSE);
96     }
97 
98     /**
99      * Verbose logging flag set thru developer debugging options and used so as to assist with
100      * in-the-field WiFi connectivity debugging.
101      *
102      * <p>{@link #isVerboseLoggingEnabled()} should be read rather than referencing this value
103      * directly, to ensure adb TAG level verbose settings are respected.
104      */
105     public static boolean sVerboseLogging;
106 
107     // TODO: Allow control of this?
108     // Combo scans can take 5-6s to complete - set to 10s.
109     private static final int WIFI_RESCAN_INTERVAL_MS = 10 * 1000;
110 
111     private final Context mContext;
112     private final WifiManager mWifiManager;
113     private final IntentFilter mFilter;
114     private final ConnectivityManager mConnectivityManager;
115     private final NetworkRequest mNetworkRequest;
116     private final AtomicBoolean mConnected = new AtomicBoolean(false);
117     private final WifiListenerExecutor mListener;
118     @VisibleForTesting Handler mWorkHandler;
119     private HandlerThread mWorkThread;
120 
121     private WifiTrackerNetworkCallback mNetworkCallback;
122 
123     /**
124      * Synchronization lock for managing concurrency between main and worker threads.
125      *
126      * <p>This lock should be held for all modifications to {@link #mInternalAccessPoints} and
127      * {@link #mScanner}.
128      */
129     private final Object mLock = new Object();
130 
131     /** The list of AccessPoints, aggregated visible ScanResults with metadata. */
132     @GuardedBy("mLock")
133     private final List<AccessPoint> mInternalAccessPoints = new ArrayList<>();
134 
135     @GuardedBy("mLock")
136     private final Set<NetworkKey> mRequestedScores = new ArraySet<>();
137 
138     /**
139      * Tracks whether fresh scan results have been received since scanning start.
140      *
141      * <p>If this variable is false, we will not invoke callbacks so that we do not
142      * update the UI with stale data / clear out existing UI elements prematurely.
143      */
144     private boolean mStaleScanResults = true;
145 
146     /**
147      * Tracks whether the latest SCAN_RESULTS_AVAILABLE_ACTION contained new scans. If not, then
148      * we treat the last scan as an aborted scan and increase the eviction timeout window to avoid
149      * completely flushing the AP list before the next successful scan completes.
150      */
151     private boolean mLastScanSucceeded = true;
152 
153     // Does not need to be locked as it only updated on the worker thread, with the exception of
154     // during onStart, which occurs before the receiver is registered on the work handler.
155     private final HashMap<String, ScanResult> mScanResultCache = new HashMap<>();
156     private boolean mRegistered;
157 
158     private NetworkInfo mLastNetworkInfo;
159     private WifiInfo mLastInfo;
160 
161     private final NetworkScoreManager mNetworkScoreManager;
162     private WifiNetworkScoreCache mScoreCache;
163     private boolean mNetworkScoringUiEnabled;
164     private long mMaxSpeedLabelScoreCacheAge;
165 
166     private static final String WIFI_SECURITY_PSK = "PSK";
167     private static final String WIFI_SECURITY_EAP = "EAP";
168     private static final String WIFI_SECURITY_SAE = "SAE";
169     private static final String WIFI_SECURITY_OWE = "OWE";
170     private static final String WIFI_SECURITY_SUITE_B_192 = "SUITE_B_192";
171 
172     @GuardedBy("mLock")
173     @VisibleForTesting
174     Scanner mScanner;
175 
newIntentFilter()176     private static IntentFilter newIntentFilter() {
177         IntentFilter filter = new IntentFilter();
178         filter.addAction(WifiManager.WIFI_STATE_CHANGED_ACTION);
179         filter.addAction(WifiManager.SCAN_RESULTS_AVAILABLE_ACTION);
180         filter.addAction(WifiManager.NETWORK_IDS_CHANGED_ACTION);
181         filter.addAction(WifiManager.SUPPLICANT_STATE_CHANGED_ACTION);
182         filter.addAction(WifiManager.CONFIGURED_NETWORKS_CHANGED_ACTION);
183         filter.addAction(WifiManager.LINK_CONFIGURATION_CHANGED_ACTION);
184         filter.addAction(WifiManager.NETWORK_STATE_CHANGED_ACTION);
185         filter.addAction(WifiManager.RSSI_CHANGED_ACTION);
186 
187         return filter;
188     }
189 
190     /**
191      * Use the lifecycle constructor below whenever possible
192      */
193     @Deprecated
WifiTracker(Context context, WifiListener wifiListener, boolean includeSaved, boolean includeScans)194     public WifiTracker(Context context, WifiListener wifiListener,
195             boolean includeSaved, boolean includeScans) {
196         this(context, wifiListener,
197                 context.getSystemService(WifiManager.class),
198                 context.getSystemService(ConnectivityManager.class),
199                 context.getSystemService(NetworkScoreManager.class),
200                 newIntentFilter());
201     }
202 
203     // TODO(sghuman): Clean up includeSaved and includeScans from all constructors and linked
204     // calling apps once IC window is complete
WifiTracker(Context context, WifiListener wifiListener, @NonNull Lifecycle lifecycle, boolean includeSaved, boolean includeScans)205     public WifiTracker(Context context, WifiListener wifiListener,
206             @NonNull Lifecycle lifecycle, boolean includeSaved, boolean includeScans) {
207         this(context, wifiListener,
208                 context.getSystemService(WifiManager.class),
209                 context.getSystemService(ConnectivityManager.class),
210                 context.getSystemService(NetworkScoreManager.class),
211                 newIntentFilter());
212 
213         lifecycle.addObserver(this);
214     }
215 
216     @VisibleForTesting
WifiTracker(Context context, WifiListener wifiListener, WifiManager wifiManager, ConnectivityManager connectivityManager, NetworkScoreManager networkScoreManager, IntentFilter filter)217     WifiTracker(Context context, WifiListener wifiListener,
218             WifiManager wifiManager, ConnectivityManager connectivityManager,
219             NetworkScoreManager networkScoreManager,
220             IntentFilter filter) {
221         mContext = context;
222         mWifiManager = wifiManager;
223         mListener = new WifiListenerExecutor(wifiListener);
224         mConnectivityManager = connectivityManager;
225 
226         // check if verbose logging developer option has been turned on or off
227         sVerboseLogging = mWifiManager != null && (mWifiManager.getVerboseLoggingLevel() > 0);
228 
229         mFilter = filter;
230 
231         mNetworkRequest = new NetworkRequest.Builder()
232                 .clearCapabilities()
233                 .addCapability(NetworkCapabilities.NET_CAPABILITY_NOT_VPN)
234                 .addTransportType(NetworkCapabilities.TRANSPORT_WIFI)
235                 .build();
236 
237         mNetworkScoreManager = networkScoreManager;
238 
239         // TODO(sghuman): Remove this and create less hacky solution for testing
240         final HandlerThread workThread = new HandlerThread(TAG
241                 + "{" + Integer.toHexString(System.identityHashCode(this)) + "}",
242                 Process.THREAD_PRIORITY_BACKGROUND);
243         workThread.start();
244         setWorkThread(workThread);
245     }
246 
247     /**
248      * Sanity warning: this wipes out mScoreCache, so use with extreme caution
249      * @param workThread substitute Handler thread, for testing purposes only
250      */
251     @VisibleForTesting
252     // TODO(sghuman): Remove this method, this needs to happen in a factory method and be passed in
253     // during construction
setWorkThread(HandlerThread workThread)254     void setWorkThread(HandlerThread workThread) {
255         mWorkThread = workThread;
256         mWorkHandler = new Handler(workThread.getLooper());
257         mScoreCache = new WifiNetworkScoreCache(mContext, new CacheListener(mWorkHandler) {
258             @Override
259             public void networkCacheUpdated(List<ScoredNetwork> networks) {
260                 if (!mRegistered) return;
261 
262                 if (Log.isLoggable(TAG, Log.VERBOSE)) {
263                     Log.v(TAG, "Score cache was updated with networks: " + networks);
264                 }
265                 updateNetworkScores();
266             }
267         });
268     }
269 
270     @Override
onDestroy()271     public void onDestroy() {
272         mWorkThread.quit();
273     }
274 
275     /**
276      * Temporarily stop scanning for wifi networks.
277      *
278      * <p>Sets {@link #mStaleScanResults} to true.
279      */
pauseScanning()280     private void pauseScanning() {
281         synchronized (mLock) {
282             if (mScanner != null) {
283                 mScanner.pause();
284                 mScanner = null;
285             }
286         }
287         mStaleScanResults = true;
288     }
289 
290     /**
291      * Resume scanning for wifi networks after it has been paused.
292      *
293      * <p>The score cache should be registered before this method is invoked.
294      */
resumeScanning()295     public void resumeScanning() {
296         synchronized (mLock) {
297             if (mScanner == null) {
298                 mScanner = new Scanner();
299             }
300 
301             if (isWifiEnabled()) {
302                 mScanner.resume();
303             }
304         }
305     }
306 
307     /**
308      * Start tracking wifi networks and scores.
309      *
310      * <p>Registers listeners and starts scanning for wifi networks. If this is not called
311      * then forceUpdate() must be called to populate getAccessPoints().
312      */
313     @Override
314     @MainThread
onStart()315     public void onStart() {
316         // fetch current ScanResults instead of waiting for broadcast of fresh results
317         forceUpdate();
318 
319         registerScoreCache();
320 
321         mNetworkScoringUiEnabled =
322                 Settings.Global.getInt(
323                         mContext.getContentResolver(),
324                         Settings.Global.NETWORK_SCORING_UI_ENABLED, 0) == 1;
325 
326         mMaxSpeedLabelScoreCacheAge =
327                 Settings.Global.getLong(
328                         mContext.getContentResolver(),
329                         Settings.Global.SPEED_LABEL_CACHE_EVICTION_AGE_MILLIS,
330                         DEFAULT_MAX_CACHED_SCORE_AGE_MILLIS);
331 
332         resumeScanning();
333         if (!mRegistered) {
334             mContext.registerReceiver(mReceiver, mFilter, null /* permission */, mWorkHandler);
335             // NetworkCallback objects cannot be reused. http://b/20701525 .
336             mNetworkCallback = new WifiTrackerNetworkCallback();
337             mConnectivityManager.registerNetworkCallback(
338                     mNetworkRequest, mNetworkCallback, mWorkHandler);
339             mRegistered = true;
340         }
341     }
342 
343 
344     /**
345      * Synchronously update the list of access points with the latest information.
346      *
347      * <p>Intended to only be invoked within {@link #onStart()}.
348      */
349     @MainThread
350     @VisibleForTesting
forceUpdate()351     void forceUpdate() {
352         mLastInfo = mWifiManager.getConnectionInfo();
353         mLastNetworkInfo = mConnectivityManager.getNetworkInfo(mWifiManager.getCurrentNetwork());
354 
355         fetchScansAndConfigsAndUpdateAccessPoints();
356     }
357 
registerScoreCache()358     private void registerScoreCache() {
359         mNetworkScoreManager.registerNetworkScoreCache(
360                 NetworkKey.TYPE_WIFI,
361                 mScoreCache,
362                 NetworkScoreManager.CACHE_FILTER_SCAN_RESULTS);
363     }
364 
requestScoresForNetworkKeys(Collection<NetworkKey> keys)365     private void requestScoresForNetworkKeys(Collection<NetworkKey> keys) {
366         if (keys.isEmpty()) return;
367 
368         if (DBG()) {
369             Log.d(TAG, "Requesting scores for Network Keys: " + keys);
370         }
371         mNetworkScoreManager.requestScores(keys.toArray(new NetworkKey[keys.size()]));
372         synchronized (mLock) {
373             mRequestedScores.addAll(keys);
374         }
375     }
376 
377     /**
378      * Stop tracking wifi networks and scores.
379      *
380      * <p>This should always be called when done with a WifiTracker (if onStart was called) to
381      * ensure proper cleanup and prevent any further callbacks from occurring.
382      *
383      * <p>Calling this method will set the {@link #mStaleScanResults} bit, which prevents
384      * {@link WifiListener#onAccessPointsChanged()} callbacks from being invoked (until the bit
385      * is unset on the next SCAN_RESULTS_AVAILABLE_ACTION).
386      */
387     @Override
388     @MainThread
onStop()389     public void onStop() {
390         if (mRegistered) {
391             mContext.unregisterReceiver(mReceiver);
392             mConnectivityManager.unregisterNetworkCallback(mNetworkCallback);
393             mRegistered = false;
394         }
395         unregisterScoreCache();
396         pauseScanning(); // and set mStaleScanResults
397 
398         mWorkHandler.removeCallbacksAndMessages(null /* remove all */);
399     }
400 
unregisterScoreCache()401     private void unregisterScoreCache() {
402         mNetworkScoreManager.unregisterNetworkScoreCache(NetworkKey.TYPE_WIFI, mScoreCache);
403 
404         // We do not want to clear the existing scores in the cache, as this method is called during
405         // stop tracking on activity pause. Hence, on resumption we want the ability to show the
406         // last known, potentially stale, scores. However, by clearing requested scores, the scores
407         // will be requested again upon resumption of tracking, and if any changes have occurred
408         // the listeners (UI) will be updated accordingly.
409         synchronized (mLock) {
410             mRequestedScores.clear();
411         }
412     }
413 
414     /**
415      * Gets the current list of access points.
416      *
417      * <p>This method is can be called on an abitrary thread by clients, but is normally called on
418      * the UI Thread by the rendering App.
419      */
420     @AnyThread
getAccessPoints()421     public List<AccessPoint> getAccessPoints() {
422         synchronized (mLock) {
423             return new ArrayList<>(mInternalAccessPoints);
424         }
425     }
426 
getManager()427     public WifiManager getManager() {
428         return mWifiManager;
429     }
430 
isWifiEnabled()431     public boolean isWifiEnabled() {
432         return mWifiManager != null && mWifiManager.isWifiEnabled();
433     }
434 
435     /**
436      * Returns the number of saved networks on the device, regardless of whether the WifiTracker
437      * is tracking saved networks.
438      * TODO(b/62292448): remove this function and update callsites to use WifiSavedConfigUtils
439      * directly.
440      */
getNumSavedNetworks()441     public int getNumSavedNetworks() {
442         return WifiSavedConfigUtils.getAllConfigs(mContext, mWifiManager).size();
443     }
444 
isConnected()445     public boolean isConnected() {
446         return mConnected.get();
447     }
448 
dump(PrintWriter pw)449     public void dump(PrintWriter pw) {
450         pw.println("  - wifi tracker ------");
451         for (AccessPoint accessPoint : getAccessPoints()) {
452             pw.println("  " + accessPoint);
453         }
454     }
455 
updateScanResultCache( final List<ScanResult> newResults)456     private ArrayMap<String, List<ScanResult>> updateScanResultCache(
457             final List<ScanResult> newResults) {
458         // TODO(sghuman): Delete this and replace it with the Map of Ap Keys to ScanResults for
459         // memory efficiency
460         for (ScanResult newResult : newResults) {
461             if (newResult.SSID == null || newResult.SSID.isEmpty()) {
462                 continue;
463             }
464             mScanResultCache.put(newResult.BSSID, newResult);
465         }
466 
467         // Evict old results in all conditions
468         evictOldScans();
469 
470         ArrayMap<String, List<ScanResult>> scanResultsByApKey = new ArrayMap<>();
471         for (ScanResult result : mScanResultCache.values()) {
472             // Ignore hidden and ad-hoc networks.
473             if (result.SSID == null || result.SSID.length() == 0 ||
474                     result.capabilities.contains("[IBSS]")) {
475                 continue;
476             }
477 
478             String apKey = AccessPoint.getKey(result);
479             List<ScanResult> resultList;
480             if (scanResultsByApKey.containsKey(apKey)) {
481                 resultList = scanResultsByApKey.get(apKey);
482             } else {
483                 resultList = new ArrayList<>();
484                 scanResultsByApKey.put(apKey, resultList);
485             }
486 
487             resultList.add(result);
488         }
489 
490         return scanResultsByApKey;
491     }
492 
493     /**
494      * Remove old scan results from the cache. If {@link #mLastScanSucceeded} is false, then
495      * increase the timeout window to avoid completely flushing the AP list before the next
496      * successful scan completes.
497      *
498      * <p>Should only ever be invoked from {@link #updateScanResultCache(List)} when
499      * {@link #mStaleScanResults} is false.
500      */
evictOldScans()501     private void evictOldScans() {
502         long evictionTimeoutMillis = mLastScanSucceeded ? MAX_SCAN_RESULT_AGE_MILLIS
503                 : MAX_SCAN_RESULT_AGE_MILLIS * 2;
504 
505         long nowMs = SystemClock.elapsedRealtime();
506         for (Iterator<ScanResult> iter = mScanResultCache.values().iterator(); iter.hasNext(); ) {
507             ScanResult result = iter.next();
508             // result timestamp is in microseconds
509             if (nowMs - result.timestamp / 1000 > evictionTimeoutMillis) {
510                 iter.remove();
511             }
512         }
513     }
514 
getWifiConfigurationForNetworkId( int networkId, final List<WifiConfiguration> configs)515     private WifiConfiguration getWifiConfigurationForNetworkId(
516             int networkId, final List<WifiConfiguration> configs) {
517         if (configs != null) {
518             for (WifiConfiguration config : configs) {
519                 if (mLastInfo != null && networkId == config.networkId &&
520                         !(config.selfAdded && config.numAssociation == 0)) {
521                     return config;
522                 }
523             }
524         }
525         return null;
526     }
527 
528     /**
529      * Retrieves latest scan results and wifi configs, then calls
530      * {@link #updateAccessPoints(List, List)}.
531      */
fetchScansAndConfigsAndUpdateAccessPoints()532     private void fetchScansAndConfigsAndUpdateAccessPoints() {
533         List<ScanResult> newScanResults = mWifiManager.getScanResults();
534 
535         // Filter all unsupported networks from the scan result list
536         final List<ScanResult> filteredScanResults =
537                 filterScanResultsByCapabilities(newScanResults);
538 
539         if (isVerboseLoggingEnabled()) {
540             Log.i(TAG, "Fetched scan results: " + filteredScanResults);
541         }
542 
543         List<WifiConfiguration> configs = mWifiManager.getConfiguredNetworks();
544         updateAccessPoints(filteredScanResults, configs);
545     }
546 
547     /** Update the internal list of access points. */
updateAccessPoints(final List<ScanResult> newScanResults, List<WifiConfiguration> configs)548     private void updateAccessPoints(final List<ScanResult> newScanResults,
549             List<WifiConfiguration> configs) {
550 
551         // Map configs and scan results necessary to make AccessPoints
552         final Map<String, WifiConfiguration> configsByKey = new ArrayMap(configs.size());
553         if (configs != null) {
554             for (WifiConfiguration config : configs) {
555                 configsByKey.put(AccessPoint.getKey(config), config);
556             }
557         }
558 
559         WifiConfiguration connectionConfig = null;
560         if (mLastInfo != null) {
561             connectionConfig = getWifiConfigurationForNetworkId(mLastInfo.getNetworkId(), configs);
562         }
563 
564         // Rather than dropping and reacquiring the lock multiple times in this method, we lock
565         // once for efficiency of lock acquisition time and readability
566         synchronized (mLock) {
567             ArrayMap<String, List<ScanResult>> scanResultsByApKey =
568                     updateScanResultCache(newScanResults);
569 
570             // Swap the current access points into a cached list for maintaining AP listeners
571             List<AccessPoint> cachedAccessPoints;
572             cachedAccessPoints = new ArrayList<>(mInternalAccessPoints);
573 
574             ArrayList<AccessPoint> accessPoints = new ArrayList<>();
575 
576             final List<NetworkKey> scoresToRequest = new ArrayList<>();
577 
578             for (Map.Entry<String, List<ScanResult>> entry : scanResultsByApKey.entrySet()) {
579                 for (ScanResult result : entry.getValue()) {
580                     NetworkKey key = NetworkKey.createFromScanResult(result);
581                     if (key != null && !mRequestedScores.contains(key)) {
582                         scoresToRequest.add(key);
583                     }
584                 }
585 
586                 AccessPoint accessPoint =
587                         getCachedOrCreate(entry.getValue(), cachedAccessPoints);
588 
589                 // Update the matching config if there is one, to populate saved network info
590                 accessPoint.update(configsByKey.get(entry.getKey()));
591 
592                 accessPoints.add(accessPoint);
593             }
594 
595             List<ScanResult> cachedScanResults = new ArrayList<>(mScanResultCache.values());
596 
597             // Add a unique Passpoint AccessPoint for each Passpoint profile's FQDN.
598             accessPoints.addAll(updatePasspointAccessPoints(
599                     mWifiManager.getAllMatchingWifiConfigs(cachedScanResults), cachedAccessPoints));
600 
601             // Add OSU Provider AccessPoints
602             accessPoints.addAll(updateOsuAccessPoints(
603                     mWifiManager.getMatchingOsuProviders(cachedScanResults), cachedAccessPoints));
604 
605             if (mLastInfo != null && mLastNetworkInfo != null) {
606                 for (AccessPoint ap : accessPoints) {
607                     ap.update(connectionConfig, mLastInfo, mLastNetworkInfo);
608                 }
609             }
610 
611             // If there were no scan results, create an AP for the currently connected network (if
612             // it exists).
613             if (accessPoints.isEmpty() && connectionConfig != null) {
614                 AccessPoint activeAp = new AccessPoint(mContext, connectionConfig);
615                 activeAp.update(connectionConfig, mLastInfo, mLastNetworkInfo);
616                 accessPoints.add(activeAp);
617                 scoresToRequest.add(NetworkKey.createFromWifiInfo(mLastInfo));
618             }
619 
620             requestScoresForNetworkKeys(scoresToRequest);
621             for (AccessPoint ap : accessPoints) {
622                 ap.update(mScoreCache, mNetworkScoringUiEnabled, mMaxSpeedLabelScoreCacheAge);
623             }
624 
625             // Pre-sort accessPoints to speed preference insertion
626             Collections.sort(accessPoints);
627 
628             // Log accesspoints that are being removed
629             if (DBG()) {
630                 Log.d(TAG,
631                         "------ Dumping AccessPoints that were not seen on this scan ------");
632                 for (AccessPoint prevAccessPoint : mInternalAccessPoints) {
633                     String prevTitle = prevAccessPoint.getTitle();
634                     boolean found = false;
635                     for (AccessPoint newAccessPoint : accessPoints) {
636                         if (newAccessPoint.getTitle() != null && newAccessPoint.getTitle()
637                                 .equals(prevTitle)) {
638                             found = true;
639                             break;
640                         }
641                     }
642                     if (!found)
643                         Log.d(TAG, "Did not find " + prevTitle + " in this scan");
644                 }
645                 Log.d(TAG,
646                         "---- Done dumping AccessPoints that were not seen on this scan ----");
647             }
648 
649             mInternalAccessPoints.clear();
650             mInternalAccessPoints.addAll(accessPoints);
651         }
652 
653         conditionallyNotifyListeners();
654     }
655 
656     @VisibleForTesting
updatePasspointAccessPoints( List<Pair<WifiConfiguration, Map<Integer, List<ScanResult>>>> passpointConfigsAndScans, List<AccessPoint> accessPointCache)657     List<AccessPoint> updatePasspointAccessPoints(
658             List<Pair<WifiConfiguration, Map<Integer, List<ScanResult>>>> passpointConfigsAndScans,
659             List<AccessPoint> accessPointCache) {
660         List<AccessPoint> accessPoints = new ArrayList<>();
661 
662         Set<String> seenFQDNs = new ArraySet<>();
663         for (Pair<WifiConfiguration,
664                 Map<Integer, List<ScanResult>>> pairing : passpointConfigsAndScans) {
665             WifiConfiguration config = pairing.first;
666             if (seenFQDNs.add(config.FQDN)) {
667                 List<ScanResult> homeScans =
668                         pairing.second.get(WifiManager.PASSPOINT_HOME_NETWORK);
669                 List<ScanResult> roamingScans =
670                         pairing.second.get(WifiManager.PASSPOINT_ROAMING_NETWORK);
671 
672                 AccessPoint accessPoint =
673                         getCachedOrCreatePasspoint(config, homeScans, roamingScans,
674                                 accessPointCache);
675                 accessPoints.add(accessPoint);
676             }
677         }
678         return accessPoints;
679     }
680 
681     @VisibleForTesting
updateOsuAccessPoints( Map<OsuProvider, List<ScanResult>> providersAndScans, List<AccessPoint> accessPointCache)682     List<AccessPoint> updateOsuAccessPoints(
683             Map<OsuProvider, List<ScanResult>> providersAndScans,
684             List<AccessPoint> accessPointCache) {
685         List<AccessPoint> accessPoints = new ArrayList<>();
686 
687         Set<OsuProvider> alreadyProvisioned = mWifiManager
688                 .getMatchingPasspointConfigsForOsuProviders(
689                         providersAndScans.keySet()).keySet();
690         for (OsuProvider provider : providersAndScans.keySet()) {
691             if (!alreadyProvisioned.contains(provider)) {
692                 AccessPoint accessPointOsu =
693                         getCachedOrCreateOsu(provider, providersAndScans.get(provider),
694                                 accessPointCache);
695                 accessPoints.add(accessPointOsu);
696             }
697         }
698         return accessPoints;
699     }
700 
getCachedOrCreate( List<ScanResult> scanResults, List<AccessPoint> cache)701     private AccessPoint getCachedOrCreate(
702             List<ScanResult> scanResults,
703             List<AccessPoint> cache) {
704         AccessPoint accessPoint = getCachedByKey(cache, AccessPoint.getKey(scanResults.get(0)));
705         if (accessPoint == null) {
706             accessPoint = new AccessPoint(mContext, scanResults);
707         } else {
708             accessPoint.setScanResults(scanResults);
709         }
710         return accessPoint;
711     }
712 
getCachedOrCreatePasspoint( WifiConfiguration config, List<ScanResult> homeScans, List<ScanResult> roamingScans, List<AccessPoint> cache)713     private AccessPoint getCachedOrCreatePasspoint(
714             WifiConfiguration config,
715             List<ScanResult> homeScans,
716             List<ScanResult> roamingScans,
717             List<AccessPoint> cache) {
718         AccessPoint accessPoint = getCachedByKey(cache, AccessPoint.getKey(config));
719         if (accessPoint == null) {
720             accessPoint = new AccessPoint(mContext, config, homeScans, roamingScans);
721         } else {
722             accessPoint.update(config);
723             accessPoint.setScanResultsPasspoint(homeScans, roamingScans);
724         }
725         return accessPoint;
726     }
727 
getCachedOrCreateOsu( OsuProvider provider, List<ScanResult> scanResults, List<AccessPoint> cache)728     private AccessPoint getCachedOrCreateOsu(
729             OsuProvider provider,
730             List<ScanResult> scanResults,
731             List<AccessPoint> cache) {
732         AccessPoint accessPoint = getCachedByKey(cache, AccessPoint.getKey(provider));
733         if (accessPoint == null) {
734             accessPoint = new AccessPoint(mContext, provider, scanResults);
735         } else {
736             accessPoint.setScanResults(scanResults);
737         }
738         return accessPoint;
739     }
740 
getCachedByKey(List<AccessPoint> cache, String key)741     private AccessPoint getCachedByKey(List<AccessPoint> cache, String key) {
742         ListIterator<AccessPoint> lit = cache.listIterator();
743         while (lit.hasNext()) {
744             AccessPoint currentAccessPoint = lit.next();
745             if (currentAccessPoint.getKey().equals(key)) {
746                 lit.remove();
747                 return currentAccessPoint;
748             }
749         }
750         return null;
751     }
752 
updateNetworkInfo(NetworkInfo networkInfo)753     private void updateNetworkInfo(NetworkInfo networkInfo) {
754         /* Sticky broadcasts can call this when wifi is disabled */
755         if (!isWifiEnabled()) {
756             clearAccessPointsAndConditionallyUpdate();
757             return;
758         }
759 
760         if (networkInfo != null) {
761             mLastNetworkInfo = networkInfo;
762             if (DBG()) {
763                 Log.d(TAG, "mLastNetworkInfo set: " + mLastNetworkInfo);
764             }
765 
766             if(networkInfo.isConnected() != mConnected.getAndSet(networkInfo.isConnected())) {
767                 mListener.onConnectedChanged();
768             }
769         }
770 
771         WifiConfiguration connectionConfig = null;
772 
773         mLastInfo = mWifiManager.getConnectionInfo();
774         if (DBG()) {
775             Log.d(TAG, "mLastInfo set as: " + mLastInfo);
776         }
777         if (mLastInfo != null) {
778             connectionConfig = getWifiConfigurationForNetworkId(mLastInfo.getNetworkId(),
779                     mWifiManager.getConfiguredNetworks());
780         }
781 
782         boolean updated = false;
783         boolean reorder = false; // Only reorder if connected AP was changed
784 
785         synchronized (mLock) {
786             for (int i = mInternalAccessPoints.size() - 1; i >= 0; --i) {
787                 AccessPoint ap = mInternalAccessPoints.get(i);
788                 boolean previouslyConnected = ap.isActive();
789                 if (ap.update(connectionConfig, mLastInfo, mLastNetworkInfo)) {
790                     updated = true;
791                     if (previouslyConnected != ap.isActive()) reorder = true;
792                 }
793                 if (ap.update(mScoreCache, mNetworkScoringUiEnabled, mMaxSpeedLabelScoreCacheAge)) {
794                     reorder = true;
795                     updated = true;
796                 }
797             }
798 
799             if (reorder) {
800                 Collections.sort(mInternalAccessPoints);
801             }
802             if (updated) {
803                 conditionallyNotifyListeners();
804             }
805         }
806     }
807 
808     /**
809      * Clears the access point list and conditionally invokes
810      * {@link WifiListener#onAccessPointsChanged()} if required (i.e. the list was not already
811      * empty).
812      */
clearAccessPointsAndConditionallyUpdate()813     private void clearAccessPointsAndConditionallyUpdate() {
814         synchronized (mLock) {
815             if (!mInternalAccessPoints.isEmpty()) {
816                 mInternalAccessPoints.clear();
817                 conditionallyNotifyListeners();
818             }
819         }
820     }
821 
822     /**
823      * Update all the internal access points rankingScores, badge and metering.
824      *
825      * <p>Will trigger a resort and notify listeners of changes if applicable.
826      *
827      * <p>Synchronized on {@link #mLock}.
828      */
updateNetworkScores()829     private void updateNetworkScores() {
830         synchronized (mLock) {
831             boolean updated = false;
832             for (int i = 0; i < mInternalAccessPoints.size(); i++) {
833                 if (mInternalAccessPoints.get(i).update(
834                         mScoreCache, mNetworkScoringUiEnabled, mMaxSpeedLabelScoreCacheAge)) {
835                     updated = true;
836                 }
837             }
838             if (updated) {
839                 Collections.sort(mInternalAccessPoints);
840                 conditionallyNotifyListeners();
841             }
842         }
843     }
844 
845     /**
846      *  Receiver for handling broadcasts.
847      *
848      *  This receiver is registered on the WorkHandler.
849      */
850     @VisibleForTesting
851     final BroadcastReceiver mReceiver = new BroadcastReceiver() {
852         @Override
853         public void onReceive(Context context, Intent intent) {
854             String action = intent.getAction();
855 
856             if (WifiManager.WIFI_STATE_CHANGED_ACTION.equals(action)) {
857                 updateWifiState(
858                         intent.getIntExtra(WifiManager.EXTRA_WIFI_STATE,
859                                 WifiManager.WIFI_STATE_UNKNOWN));
860             } else if (WifiManager.SCAN_RESULTS_AVAILABLE_ACTION.equals(action)) {
861                 mStaleScanResults = false;
862                 mLastScanSucceeded =
863                         intent.getBooleanExtra(WifiManager.EXTRA_RESULTS_UPDATED, true);
864 
865                 fetchScansAndConfigsAndUpdateAccessPoints();
866             } else if (WifiManager.CONFIGURED_NETWORKS_CHANGED_ACTION.equals(action)
867                     || WifiManager.LINK_CONFIGURATION_CHANGED_ACTION.equals(action)) {
868                 fetchScansAndConfigsAndUpdateAccessPoints();
869             } else if (WifiManager.NETWORK_STATE_CHANGED_ACTION.equals(action)) {
870                 // TODO(sghuman): Refactor these methods so they cannot result in duplicate
871                 // onAccessPointsChanged updates being called from this intent.
872                 NetworkInfo info = intent.getParcelableExtra(WifiManager.EXTRA_NETWORK_INFO);
873                 updateNetworkInfo(info);
874                 fetchScansAndConfigsAndUpdateAccessPoints();
875             } else if (WifiManager.RSSI_CHANGED_ACTION.equals(action)) {
876                 NetworkInfo info =
877                         mConnectivityManager.getNetworkInfo(mWifiManager.getCurrentNetwork());
878                 updateNetworkInfo(info);
879             }
880         }
881     };
882 
883     /**
884      * Handles updates to WifiState.
885      *
886      * <p>If Wifi is not enabled in the enabled state, {@link #mStaleScanResults} will be set to
887      * true.
888      */
updateWifiState(int state)889     private void updateWifiState(int state) {
890         if (isVerboseLoggingEnabled()) {
891             Log.d(TAG, "updateWifiState: " + state);
892         }
893         if (state == WifiManager.WIFI_STATE_ENABLED) {
894             synchronized (mLock) {
895                 if (mScanner != null) {
896                     // We only need to resume if mScanner isn't null because
897                     // that means we want to be scanning.
898                     mScanner.resume();
899                 }
900             }
901         } else {
902             clearAccessPointsAndConditionallyUpdate();
903             mLastInfo = null;
904             mLastNetworkInfo = null;
905             synchronized (mLock) {
906                 if (mScanner != null) {
907                     mScanner.pause();
908                 }
909             }
910             mStaleScanResults = true;
911         }
912         mListener.onWifiStateChanged(state);
913     }
914 
915     private final class WifiTrackerNetworkCallback extends ConnectivityManager.NetworkCallback {
onCapabilitiesChanged(Network network, NetworkCapabilities nc)916         public void onCapabilitiesChanged(Network network, NetworkCapabilities nc) {
917             if (network.equals(mWifiManager.getCurrentNetwork())) {
918                 // TODO(sghuman): Investigate whether this comment still holds true and if it makes
919                 // more sense fetch the latest network info here:
920 
921                 // We don't send a NetworkInfo object along with this message, because even if we
922                 // fetch one from ConnectivityManager, it might be older than the most recent
923                 // NetworkInfo message we got via a WIFI_STATE_CHANGED broadcast.
924                 updateNetworkInfo(null);
925             }
926         }
927     }
928 
929     @VisibleForTesting
930     class Scanner extends Handler {
931         static final int MSG_SCAN = 0;
932 
933         private int mRetry = 0;
934 
resume()935         void resume() {
936             if (isVerboseLoggingEnabled()) {
937                 Log.d(TAG, "Scanner resume");
938             }
939             if (!hasMessages(MSG_SCAN)) {
940                 sendEmptyMessage(MSG_SCAN);
941             }
942         }
943 
pause()944         void pause() {
945             if (isVerboseLoggingEnabled()) {
946                 Log.d(TAG, "Scanner pause");
947             }
948             mRetry = 0;
949             removeMessages(MSG_SCAN);
950         }
951 
952         @VisibleForTesting
isScanning()953         boolean isScanning() {
954             return hasMessages(MSG_SCAN);
955         }
956 
957         @Override
handleMessage(Message message)958         public void handleMessage(Message message) {
959             if (message.what != MSG_SCAN) return;
960             if (mWifiManager.startScan()) {
961                 mRetry = 0;
962             } else if (++mRetry >= 3) {
963                 mRetry = 0;
964                 if (mContext != null) {
965                     Toast.makeText(mContext, R.string.wifi_fail_to_scan, Toast.LENGTH_LONG).show();
966                 }
967                 return;
968             }
969             sendEmptyMessageDelayed(MSG_SCAN, WIFI_RESCAN_INTERVAL_MS);
970         }
971     }
972 
973     /** A restricted multimap for use in constructAccessPoints */
974     private static class Multimap<K,V> {
975         private final HashMap<K,List<V>> store = new HashMap<K,List<V>>();
976         /** retrieve a non-null list of values with key K */
getAll(K key)977         List<V> getAll(K key) {
978             List<V> values = store.get(key);
979             return values != null ? values : Collections.<V>emptyList();
980         }
981 
put(K key, V val)982         void put(K key, V val) {
983             List<V> curVals = store.get(key);
984             if (curVals == null) {
985                 curVals = new ArrayList<V>(3);
986                 store.put(key, curVals);
987             }
988             curVals.add(val);
989         }
990     }
991 
992     /**
993      * Wraps the given {@link WifiListener} instance and executes its methods on the Main Thread.
994      *
995      * <p>Also logs all callbacks invocations when verbose logging is enabled.
996      */
997     @VisibleForTesting class WifiListenerExecutor implements WifiListener {
998 
999         private final WifiListener mDelegatee;
1000 
WifiListenerExecutor(WifiListener listener)1001         public WifiListenerExecutor(WifiListener listener) {
1002             mDelegatee = listener;
1003         }
1004 
1005         @Override
onWifiStateChanged(int state)1006         public void onWifiStateChanged(int state) {
1007             runAndLog(() -> mDelegatee.onWifiStateChanged(state),
1008                     String.format("Invoking onWifiStateChanged callback with state %d", state));
1009         }
1010 
1011         @Override
onConnectedChanged()1012         public void onConnectedChanged() {
1013             runAndLog(mDelegatee::onConnectedChanged, "Invoking onConnectedChanged callback");
1014         }
1015 
1016         @Override
onAccessPointsChanged()1017         public void onAccessPointsChanged() {
1018             runAndLog(mDelegatee::onAccessPointsChanged, "Invoking onAccessPointsChanged callback");
1019         }
1020 
runAndLog(Runnable r, String verboseLog)1021         private void runAndLog(Runnable r, String verboseLog) {
1022             ThreadUtils.postOnMainThread(() -> {
1023                 if (mRegistered) {
1024                     if (isVerboseLoggingEnabled()) {
1025                         Log.i(TAG, verboseLog);
1026                     }
1027                     r.run();
1028                 }
1029             });
1030         }
1031     }
1032 
1033     /**
1034      * WifiListener interface that defines callbacks indicating state changes in WifiTracker.
1035      *
1036      * <p>All callbacks are invoked on the MainThread.
1037      */
1038     public interface WifiListener {
1039         /**
1040          * Called when the state of Wifi has changed, the state will be one of
1041          * the following.
1042          *
1043          * <li>{@link WifiManager#WIFI_STATE_DISABLED}</li>
1044          * <li>{@link WifiManager#WIFI_STATE_ENABLED}</li>
1045          * <li>{@link WifiManager#WIFI_STATE_DISABLING}</li>
1046          * <li>{@link WifiManager#WIFI_STATE_ENABLING}</li>
1047          * <li>{@link WifiManager#WIFI_STATE_UNKNOWN}</li>
1048          * <p>
1049          *
1050          * @param state The new state of wifi.
1051          */
onWifiStateChanged(int state)1052         void onWifiStateChanged(int state);
1053 
1054         /**
1055          * Called when the connection state of wifi has changed and
1056          * {@link WifiTracker#isConnected()} should be called to get the updated state.
1057          */
onConnectedChanged()1058         void onConnectedChanged();
1059 
1060         /**
1061          * Called to indicate the list of AccessPoints has been updated and
1062          * {@link WifiTracker#getAccessPoints()} should be called to get the updated list.
1063          */
onAccessPointsChanged()1064         void onAccessPointsChanged();
1065     }
1066 
1067     /**
1068      * Invokes {@link WifiListenerExecutor#onAccessPointsChanged()} iif {@link #mStaleScanResults}
1069      * is false.
1070      */
conditionallyNotifyListeners()1071     private void conditionallyNotifyListeners() {
1072         if (mStaleScanResults) {
1073             return;
1074         }
1075 
1076         mListener.onAccessPointsChanged();
1077     }
1078 
1079     /**
1080      * Filters unsupported networks from scan results. New WPA3 networks and OWE networks
1081      * may not be compatible with the device HW/SW.
1082      * @param scanResults List of scan results
1083      * @return List of filtered scan results based on local device capabilities
1084      */
filterScanResultsByCapabilities(List<ScanResult> scanResults)1085     private List<ScanResult> filterScanResultsByCapabilities(List<ScanResult> scanResults) {
1086         if (scanResults == null) {
1087             return null;
1088         }
1089 
1090         // Get and cache advanced capabilities
1091         final boolean isOweSupported = mWifiManager.isEnhancedOpenSupported();
1092         final boolean isSaeSupported = mWifiManager.isWpa3SaeSupported();
1093         final boolean isSuiteBSupported = mWifiManager.isWpa3SuiteBSupported();
1094 
1095         List<ScanResult> filteredScanResultList = new ArrayList<>();
1096 
1097         // Iterate through the list of scan results and filter out APs which are not
1098         // compatible with our device.
1099         for (ScanResult scanResult : scanResults) {
1100             if (scanResult.capabilities.contains(WIFI_SECURITY_PSK)) {
1101                 // All devices (today) support RSN-PSK or WPA-PSK
1102                 // Add this here because some APs may support both PSK and SAE and the check
1103                 // below will filter it out.
1104                 filteredScanResultList.add(scanResult);
1105                 continue;
1106             }
1107 
1108             if ((scanResult.capabilities.contains(WIFI_SECURITY_SUITE_B_192) && !isSuiteBSupported)
1109                     || (scanResult.capabilities.contains(WIFI_SECURITY_SAE) && !isSaeSupported)
1110                     || (scanResult.capabilities.contains(WIFI_SECURITY_OWE) && !isOweSupported)) {
1111                 if (isVerboseLoggingEnabled()) {
1112                     Log.v(TAG, "filterScanResultsByCapabilities: Filtering SSID "
1113                             + scanResult.SSID + " with capabilities: " + scanResult.capabilities);
1114                 }
1115             } else {
1116                 // Safe to add
1117                 filteredScanResultList.add(scanResult);
1118             }
1119         }
1120 
1121         return filteredScanResultList;
1122     }
1123 }
1124