Modify BSSID blacklist behavior

The new behaviors are:
(1) If a BSSID get association rejection three times, blacklist it
(2) After 30 min of blacklist, we re-enable it again.
(3) If any connect successfully to the BSSID, re-enable it

BUG=27166673

Change-Id: I70f439b524ffc304d6c61744f90389f47006341b

3 files changed, 178 insertions, 32 deletions

diff --git a/service/java/com/android/server/wifi/WifiQualifiedNetworkSelection.java b/service/java/com/android/server/wifi/WifiQualifiedNetworkSelection.java
index 869bbc7ba..82e82fdc3 100644
--- a/service/java/com/android/server/wifi/WifiQualifiedNetworkSelection.java
+++ b/service/java/com/android/server/wifi/WifiQualifiedNetworkSelection.java
@@ -31,8 +31,10 @@ import com.android.internal.R;
 
 import java.io.FileDescriptor;
 import java.io.PrintWriter;
-import java.util.HashSet;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
+import java.util.Set;
 
 class WifiQualifiedNetworkSelector {
     private WifiConfigStore mWifiConfigStore;
@@ -72,6 +74,8 @@ class WifiQualifiedNetworkSelector {
     public static final int LAST_SELECTION_AWARD = 480;
     public static final int PASSPOINT_SECURITY_AWARD = 40;
     public static final int SECURITY_AWARD = 80;
+    public static final int BSSID_BLACKLIST_THRESHOLD = 3;
+    public static final int BSSID_BLACKLIST_EXPIRE_TIME = 30 * 60 * 1000;
     private final int mNoIntnetPenalty;
     //TODO: check whether we still need this one when we update the scan manager
     public static final int SCAN_RESULT_MAXIMUNM_AGE = 40000;
@@ -87,7 +91,19 @@ class WifiQualifiedNetworkSelector {
     private int mPasspointSecurityAward = PASSPOINT_SECURITY_AWARD;
     private int mSecurityAward = SECURITY_AWARD;
     private int mUserPreferedBand = WifiManager.WIFI_FREQUENCY_BAND_AUTO;
-    private HashSet<String> mBssidBlacklist = new HashSet<String>();
+    private Map<String, BssidBlacklistStatus> mBssidBlacklist =
+            new HashMap<String, BssidBlacklistStatus>();
+
+    /**
+     * class save the blacklist status of a given BSSID
+     */
+    private static class BssidBlacklistStatus {
+        //how many times it is requested to be blacklisted (association rejection trigger this)
+        int mCounter;
+        boolean mIsBlacklisted;
+        long mBlacklistedTimeStamp = INVALID_TIME_STAMP;
+    }
+
     private void qnsLog(String log) {
         if (mDbg) {
             mLocalLog.log(log);
@@ -512,26 +528,60 @@ class WifiQualifiedNetworkSelector {
      * @param enable -- true enable a bssid if it has been disabled
      *               -- false disable a bssid
      */
-    public boolean enableBssidForQualitynetworkSelection(String bssid, boolean enable) {
+    public boolean enableBssidForQualityNetworkSelection(String bssid, boolean enable) {
         if (enable) {
-            return mBssidBlacklist.remove(bssid);
+            return (mBssidBlacklist.remove(bssid) != null);
         } else {
             if (bssid != null) {
-                mBssidBlacklist.add(bssid);
-                return true;
+                BssidBlacklistStatus status = mBssidBlacklist.get(bssid);
+                if (status == null) {
+                    //first time
+                    BssidBlacklistStatus newStatus = new BssidBlacklistStatus();
+                    newStatus.mCounter++;
+                    mBssidBlacklist.put(bssid, newStatus);
+                } else if (!status.mIsBlacklisted) {
+                    status.mCounter++;
+                    if (status.mCounter >= BSSID_BLACKLIST_THRESHOLD) {
+                        status.mIsBlacklisted = true;
+                        status.mBlacklistedTimeStamp = mClock.currentTimeMillis();
+                        return true;
+                    }
+                }
             }
         }
         return false;
     }
 
     /**
+     * update the buffered BSSID blacklist
+     *
+     * Go through the whole buffered BSSIDs blacklist and check when the BSSIDs is blocked. If they
+     * were blacked before BSSID_BLACKLIST_EXPIRE_TIME, re-enable it again.
+     */
+    private void updateBssidBlacklist() {
+        Set<String> keys = mBssidBlacklist.keySet();
+        if (keys != null && keys.size() > 0) {
+            for (String bssid : keys) {
+                BssidBlacklistStatus status = mBssidBlacklist.get(bssid);
+                if (status != null && status.mIsBlacklisted) {
+                    if (mClock.currentTimeMillis() - status.mBlacklistedTimeStamp
+                            >= BSSID_BLACKLIST_EXPIRE_TIME) {
+                        enableBssidForQualityNetworkSelection(bssid, true);
+                    }
+                }
+            }
+        }
+    }
+
+    /**
      * Check whether a bssid is disabled
      * @param bssid -- the bssid to check
      * @return true -- bssid is disabled
      *         false -- bssid is not disabled
      */
     public boolean isBssidDisabled(String bssid) {
-        return mBssidBlacklist.contains(bssid);
+        BssidBlacklistStatus status = mBssidBlacklist.get(bssid);
+        return status == null ? false : status.mIsBlacklisted;
     }
 
     /**
@@ -595,6 +645,7 @@ class WifiQualifiedNetworkSelector {
         }
 
         updateSavedNetworkSelectionStatus();
+        updateBssidBlacklist();
 
         StringBuffer lowSignalScan = new StringBuffer();
         StringBuffer notSavedScan = new StringBuffer();
diff --git a/service/java/com/android/server/wifi/WifiStateMachine.java b/service/java/com/android/server/wifi/WifiStateMachine.java
index aad147161..a57d55a38 100644
--- a/service/java/com/android/server/wifi/WifiStateMachine.java
+++ b/service/java/com/android/server/wifi/WifiStateMachine.java
@@ -6953,7 +6953,7 @@ public class WifiStateMachine extends StateMachine implements WifiNative.WifiPno
                         // If we have a BSSID, tell configStore to black list it
                         synchronized(mScanResultCache) {
                             didBlackListBSSID = mWifiQualifiedNetworkSelector
-                                    .enableBssidForQualitynetworkSelection(bssid, false);
+                                    .enableBssidForQualityNetworkSelection(bssid, false);
                         }
                     }
 
@@ -7775,6 +7775,8 @@ public class WifiStateMachine extends StateMachine implements WifiNative.WifiPno
 
                     mWifiInfo.setBSSID(mLastBssid);
                     mWifiInfo.setNetworkId(mLastNetworkId);
+                    mWifiQualifiedNetworkSelector
+                            .enableBssidForQualityNetworkSelection(mLastBssid, true);
                     sendNetworkStateChangeBroadcast(mLastBssid);
                     transitionTo(mObtainingIpState);
                     break;
@@ -8671,7 +8673,7 @@ public class WifiStateMachine extends StateMachine implements WifiNative.WifiPno
                         mLastBssid = (String) message.obj;
                         mWifiInfo.setBSSID(mLastBssid);
                         mWifiInfo.setNetworkId(mLastNetworkId);
-                        mWifiQualifiedNetworkSelector.enableBssidForQualitynetworkSelection(
+                        mWifiQualifiedNetworkSelector.enableBssidForQualityNetworkSelection(
                                 mLastBssid, true);
                         sendNetworkStateChangeBroadcast(mLastBssid);
                         transitionTo(mObtainingIpState);
diff --git a/tests/wifitests/src/com/android/server/wifi/WifiQualifiedNetworkSelectionTest.java b/tests/wifitests/src/com/android/server/wifi/WifiQualifiedNetworkSelectionTest.java
index 987246566..ce2a53cf0 100644
--- a/tests/wifitests/src/com/android/server/wifi/WifiQualifiedNetworkSelectionTest.java
+++ b/tests/wifitests/src/com/android/server/wifi/WifiQualifiedNetworkSelectionTest.java
@@ -677,22 +677,29 @@ public class WifiQualifiedNetworkSelectionTest {
         assertEquals("bssidB should be enabled by default",
                 mWifiQualifiedNetworkSelector.isBssidDisabled(bssidB), false);
 
-        //disable bssidA, check whether A is dsiabled and B is still enabled
-        mWifiQualifiedNetworkSelector.enableBssidForQualitynetworkSelection(bssidA, false);
+        //disable bssidA 3 times, check whether A is dsiabled and B is still enabled
+        mWifiQualifiedNetworkSelector.enableBssidForQualityNetworkSelection(bssidA, false);
+        assertEquals("bssidA should be disabled",
+                mWifiQualifiedNetworkSelector.isBssidDisabled(bssidA), false);
+        mWifiQualifiedNetworkSelector.enableBssidForQualityNetworkSelection(bssidA, false);
+        assertEquals("bssidA should be disabled",
+                mWifiQualifiedNetworkSelector.isBssidDisabled(bssidA), false);
+        mWifiQualifiedNetworkSelector.enableBssidForQualityNetworkSelection(bssidA, false);
         assertEquals("bssidA should be disabled",
                 mWifiQualifiedNetworkSelector.isBssidDisabled(bssidA), true);
         assertEquals("bssidB should still be enabled",
                 mWifiQualifiedNetworkSelector.isBssidDisabled(bssidB), false);
 
         //re-enable bssidA, check whether A is dsiabled and B is still enabled
-        mWifiQualifiedNetworkSelector.enableBssidForQualitynetworkSelection(bssidA, true);
+        mWifiQualifiedNetworkSelector.enableBssidForQualityNetworkSelection(bssidA, true);
         assertEquals("bssidA should be enabled by default",
                 mWifiQualifiedNetworkSelector.isBssidDisabled(bssidA), false);
         assertEquals("bssidB should be enabled by default",
                 mWifiQualifiedNetworkSelector.isBssidDisabled(bssidB), false);
 
         //make sure illegal input will not cause crash
-        mWifiQualifiedNetworkSelector.enableBssidForQualitynetworkSelection(null, true);
+        mWifiQualifiedNetworkSelector.enableBssidForQualityNetworkSelection(null, false);
+        mWifiQualifiedNetworkSelector.enableBssidForQualityNetworkSelection(null, true);
     }
 
     /**
@@ -726,7 +733,51 @@ public class WifiQualifiedNetworkSelectionTest {
         scanResultLinkConfiguration(savedConfigs, scanDetails);
         ScanResult chosenScanResult = scanDetails.get(0).getScanResult();
 
-        mWifiQualifiedNetworkSelector.enableBssidForQualitynetworkSelection(bssids[1], false);
+        mWifiQualifiedNetworkSelector.enableBssidForQualityNetworkSelection(bssids[1], false);
+        mWifiQualifiedNetworkSelector.enableBssidForQualityNetworkSelection(bssids[1], false);
+        mWifiQualifiedNetworkSelector.enableBssidForQualityNetworkSelection(bssids[1], false);
+        WifiConfiguration candidate = mWifiQualifiedNetworkSelector.selectQualifiedNetwork(false,
+                false, scanDetails, false, false, true, false);
+
+        verifySelectedResult(chosenScanResult, candidate);
+    }
+
+    /**
+     * Case #14    re-choose the disabled BSSID after it is re-enabled
+     *
+     * In this test. we simulate following scenario:
+     * WifiStateMachine is under disconnected state
+     * Two networks test1, test2 are secured network and found in scan results
+     * Both network are enabled
+     * test1 is @ 2GHz with RSSI -65
+     * test2 is @ 5Ghz with RSSI -50
+     * test2's BSSID is disabled
+     *
+     * expected return test2 since test2's BSSID has been enabled again
+     */
+    @Test
+    public void networkChooseWithOneBssidReenaabled() {
+        String[] ssids = DEFAULT_SSIDS;
+        String[] bssids = DEFAULT_BSSIDS;
+        int[] frequencies = {2437, 5180};
+        String[] caps = {"[WPA2-EAP-CCMP][ESS]", "[WPA2-EAP-CCMP][ESS][ESS]"};
+        int[] levels = {-65, -50};
+        int[] security = {SECURITY_PSK, SECURITY_PSK};
+
+        List<ScanDetail> scanDetails = getScanDetails(ssids, bssids, frequencies, caps, levels);
+        WifiConfiguration[] savedConfigs = generateWifiConfigurations(ssids, security);
+        prepareConfigStore(savedConfigs);
+
+        final List<WifiConfiguration> savedNetwork = Arrays.asList(savedConfigs);
+        when(mWifiConfigStore.getConfiguredNetworks()).thenReturn(savedNetwork);
+        scanResultLinkConfiguration(savedConfigs, scanDetails);
+        ScanResult chosenScanResult = scanDetails.get(1).getScanResult();
+
+        mWifiQualifiedNetworkSelector.enableBssidForQualityNetworkSelection(bssids[1], false);
+        mWifiQualifiedNetworkSelector.enableBssidForQualityNetworkSelection(bssids[1], false);
+        mWifiQualifiedNetworkSelector.enableBssidForQualityNetworkSelection(bssids[1], false);
+        //re-enable it
+        mWifiQualifiedNetworkSelector.enableBssidForQualityNetworkSelection(bssids[1], true);
         WifiConfiguration candidate = mWifiQualifiedNetworkSelector.selectQualifiedNetwork(false,
                 false, scanDetails, false, false, true, false);
 
@@ -734,7 +785,49 @@ public class WifiQualifiedNetworkSelectionTest {
     }
 
     /**
-     * Case #14    do not choose the SSID has been disabled
+     * Case #15    re-choose the disabled BSSID after its disability has expired
+     *
+     * In this test. we simulate following scenario:
+     * WifiStateMachine is under disconnected state
+     * Two networks test1, test2 are secured network and found in scan results
+     * Both network are enabled
+     * test1 is @ 2GHz with RSSI -65
+     * test2 is @ 5Ghz with RSSI -50
+     * test2's BSSID is disabled
+     *
+     * expected return test2 since test2's BSSID has been enabled again
+     */
+    @Test
+    public void networkChooseWithOneBssidDisableExpire() {
+        String[] ssids = DEFAULT_SSIDS;
+        String[] bssids = DEFAULT_BSSIDS;
+        int[] frequencies = {2437, 5180};
+        String[] caps = {"[WPA2-EAP-CCMP][ESS]", "[WPA2-EAP-CCMP][ESS][ESS]"};
+        int[] levels = {-65, -50};
+        int[] security = {SECURITY_PSK, SECURITY_PSK};
+
+        List<ScanDetail> scanDetails = getScanDetails(ssids, bssids, frequencies, caps, levels);
+        WifiConfiguration[] savedConfigs = generateWifiConfigurations(ssids, security);
+        prepareConfigStore(savedConfigs);
+
+        final List<WifiConfiguration> savedNetwork = Arrays.asList(savedConfigs);
+        when(mWifiConfigStore.getConfiguredNetworks()).thenReturn(savedNetwork);
+        scanResultLinkConfiguration(savedConfigs, scanDetails);
+        ScanResult chosenScanResult = scanDetails.get(1).getScanResult();
+
+        mWifiQualifiedNetworkSelector.enableBssidForQualityNetworkSelection(bssids[1], false);
+        mWifiQualifiedNetworkSelector.enableBssidForQualityNetworkSelection(bssids[1], false);
+        mWifiQualifiedNetworkSelector.enableBssidForQualityNetworkSelection(bssids[1], false);
+        //re-enable it
+        when(mClock.currentTimeMillis()).thenReturn(System.currentTimeMillis()
+                + WifiQualifiedNetworkSelector.BSSID_BLACKLIST_EXPIRE_TIME);
+        WifiConfiguration candidate = mWifiQualifiedNetworkSelector.selectQualifiedNetwork(false,
+                false, scanDetails, false, false, true, false);
+
+        verifySelectedResult(chosenScanResult, candidate);
+    }
+    /**
+     * Case #16    do not choose the SSID has been disabled
      *
      * In this test. we simulate following scenario:
      * WifiStateMachine is under disconnected state
@@ -744,7 +837,7 @@ public class WifiQualifiedNetworkSelectionTest {
      * test2 is @ 5Ghz with RSSI -50
      * test2's SSID is disabled
      *
-     * expected return test1 since test2's BSSID has been disabled
+     * expected return test1 since test2's SSID has been disabled
      */
     @Test
     public void networkChooseWithOneSsidDisabled() {
@@ -773,7 +866,7 @@ public class WifiQualifiedNetworkSelectionTest {
     }
 
     /**
-     * Case #15    do not make QNS is link is bouncing now
+     * Case #17    do not make QNS is link is bouncing now
      *
      * In this test. we simulate following scenario:
      * WifiStateMachine is under disconnected state and currently is under link bouncing
@@ -809,7 +902,7 @@ public class WifiQualifiedNetworkSelectionTest {
     }
 
     /**
-     * Case #16    QNS with very short gap
+     * Case #18    QNS with very short gap
      *
      * In this test. we simulate following scenario:
      * WifiStateMachine is under disconnected state
@@ -848,7 +941,7 @@ public class WifiQualifiedNetworkSelectionTest {
     //Unit test for Connected State
 
     /**
-     * Case #17    no QNS with very short gap when connected
+     * Case #19    no QNS with very short gap when connected
      * In this test. we simulate following scenario:
      * WifiStateMachine is under connected state and test2 is connected
      * When WifiStateMachine is already in connected state, if last QNS is made in less than
@@ -883,7 +976,7 @@ public class WifiQualifiedNetworkSelectionTest {
     }
 
     /**
-     * Case #18    force QNS with very short gap under connection
+     * Case #20    force QNS with very short gap under connection
      * In this test. we simulate following scenario:
      * WifiStateMachine is under connected state and test2 is connected
      * When WifiStateMachine is already in connected state, if last QNS is made in less than
@@ -920,7 +1013,7 @@ public class WifiQualifiedNetworkSelectionTest {
     }
 
     /**
-     * Case #19    no QNS when connected and user do not allow switch when connected
+     * Case #21    no QNS when connected and user do not allow switch when connected
      *
      * In this test. we simulate following scenario:
      * WifiStateMachine is under connected state and test2 is connected
@@ -951,7 +1044,7 @@ public class WifiQualifiedNetworkSelectionTest {
     }
 
     /**
-     * Case #20    no new QNS if current network is qualified already
+     * Case #22    no new QNS if current network is qualified already
      *
      * In this test. we simulate following scenario:
      * WifiStateMachine is under connected state and test2 is connected
@@ -997,7 +1090,7 @@ public class WifiQualifiedNetworkSelectionTest {
     }
 
     /**
-     * Case #21    No new QNS when link bouncing when connected
+     * Case #23    No new QNS when link bouncing when connected
      *
      * In this test. we simulate following scenario:
      * WifiStateMachine is under connected state and test2 is connected
@@ -1037,7 +1130,7 @@ public class WifiQualifiedNetworkSelectionTest {
     }
 
     /**
-     * Case #22    Qualified network need to be on 5GHz
+     * Case #24    Qualified network need to be on 5GHz
      *
      * In this test. we simulate following scenario:
      * WifiStateMachine is under connected state and connected to test2
@@ -1078,7 +1171,7 @@ public class WifiQualifiedNetworkSelectionTest {
     }
 
     /**
-     * Case #23    Qualified network need to be secured
+     * Case #25    Qualified network need to be secured
      *
      * In this test. we simulate following scenario:
      * WifiStateMachine is under connected state and current connects to test2
@@ -1125,7 +1218,7 @@ public class WifiQualifiedNetworkSelectionTest {
     }
 
     /**
-     * Case #24    ephemeral network can not be qualified network
+     * Case #26    ephemeral network can not be qualified network
      *
      * In this test. we simulate following scenario:
      * WifiStateMachine is under connected state and current connected to test2
@@ -1172,7 +1265,7 @@ public class WifiQualifiedNetworkSelectionTest {
     }
 
     /**
-     * Case #25    low signal network can not be Qualified network (5GHz)
+     * Case #27    low signal network can not be Qualified network (5GHz)
      *
      * In this test. we simulate following scenario:
      * WifiStateMachine is under connected state and current connected to test2
@@ -1219,7 +1312,7 @@ public class WifiQualifiedNetworkSelectionTest {
     }
 
     /**
-     * Case #26    low signal network can not be Qualified network (2.4GHz)
+     * Case #28    low signal network can not be Qualified network (2.4GHz)
      *
      * In this test. we simulate following scenario:
      * WifiStateMachine is under connected state and current connected to test2
@@ -1266,7 +1359,7 @@ public class WifiQualifiedNetworkSelectionTest {
     }
 
     /**
-     * Case #27    Choose current network due to current network bonus
+     * Case #29    Choose current network due to current network bonus
      *
      * In this test. we simulate following scenario:
      * WifiStateMachine is under connected state and current connected to test2
@@ -1313,7 +1406,7 @@ public class WifiQualifiedNetworkSelectionTest {
     }
 
     /**
-     * Case #28    choose another network due to current network's signal is too low
+     * Case #30    choose another network due to current network's signal is too low
      *
      * In this test. we simulate following scenario:
      * WifiStateMachine is under connected state and current connected to test2
@@ -1359,7 +1452,7 @@ public class WifiQualifiedNetworkSelectionTest {
     }
 
     /**
-     * Case #29    Choose current BSSID due to current BSSID bonus
+     * Case #31    Choose current BSSID due to current BSSID bonus
      *
      * In this test. we simulate following scenario:
      * WifiStateMachine is under connected state and current connected to test2
@@ -1410,7 +1503,7 @@ public class WifiQualifiedNetworkSelectionTest {
     }
 
     /**
-     * Case #30    Choose another BSSID due to current BSSID's rssi is too low
+     * Case #32    Choose another BSSID due to current BSSID's rssi is too low
      *
      * In this test. we simulate following scenario:
      * WifiStateMachine is under connected state and current connected to test2