Only auto-disqualify 2.4GHz NWs when 5GHz NWs are available

The WifiSelector logic automatically disqualifies 2.4GHz
networks so that we always go looking for a candidate 5GHz
network. This is the right thing to do so long as there are
5GHz candidates. For 5GHz candidates to be available:
1) 5Ghz must be supported by the device
2) 5GHz networks must be found by a scan
3) 5GHz must be enabled by the user (not always configurable)

Thus, for cases where 5GHz networks aren't available for
whatever reason, we should only disqualify 2.4GHz networks
using the established RSSI-based logic that is applied in
other cases.

Exempt-From-Owner-Approval: Owners file out of date
Bug: 36226123
Test: test2GhzQualifiedNo5GhzAvailable,
      test2GhzHighQuality5GhzAvailable,
      test2GhzNotQualifiedOther2GhzAvailable,
      test5GhzNotQualifiedLowRssi,
      test5GhzQualified
Merged-In: I3632e056c9890c7ac6607f72b21e42d34ec0386d
Change-Id: I3632e056c9890c7ac6607f72b21e42d34ec0386d

1 files changed, 141 insertions, 92 deletions

diff --git a/tests/wifitests/src/com/android/server/wifi/WifiNetworkSelectorTest.java b/tests/wifitests/src/com/android/server/wifi/WifiNetworkSelectorTest.java
index 7a0d2cd91..efc413e0d 100644
--- a/tests/wifitests/src/com/android/server/wifi/WifiNetworkSelectorTest.java
+++ b/tests/wifitests/src/com/android/server/wifi/WifiNetworkSelectorTest.java
@@ -74,6 +74,10 @@ public class WifiNetworkSelectorTest {
                 R.integer.config_wifi_framework_wifi_score_low_rssi_threshold_24GHz);
         mThresholdQualifiedRssi5G = mResource.getInteger(
                 R.integer.config_wifi_framework_wifi_score_low_rssi_threshold_5GHz);
+        mThresholdSaturatedRssi2G = mResource.getInteger(
+                R.integer.config_wifi_framework_wifi_score_good_rssi_threshold_24GHz);
+        mThresholdSaturatedRssi5G = mResource.getInteger(
+                R.integer.config_wifi_framework_wifi_score_good_rssi_threshold_5GHz);
     }
 
     /** Cleans up test. */
@@ -107,7 +111,8 @@ public class WifiNetworkSelectorTest {
                     List<Pair<ScanDetail, WifiConfiguration>> connectableNetworks) {
             ScanDetail scanDetail = scanDetails.get(0);
             mWifiConfigManager.setNetworkCandidateScanResult(0, scanDetail.getScanResult(), 100);
-
+            assertNotNull("Saved network must not be null",
+                    mWifiConfigManager.getConfiguredNetworkForScanDetailAndCache(scanDetail));
             return mWifiConfigManager.getConfiguredNetworkForScanDetailAndCache(scanDetail);
         }
     }
@@ -124,6 +129,8 @@ public class WifiNetworkSelectorTest {
     private int mThresholdMinimumRssi5G;
     private int mThresholdQualifiedRssi2G;
     private int mThresholdQualifiedRssi5G;
+    private int mThresholdSaturatedRssi2G;
+    private int mThresholdSaturatedRssi5G;
 
     private void setupContext() {
         when(mContext.getResources()).thenReturn(mResource);
@@ -144,6 +151,12 @@ public class WifiNetworkSelectorTest {
         when(mResource.getInteger(
                 R.integer.config_wifi_framework_wifi_score_bad_rssi_threshold_24GHz))
                 .thenReturn(-85);
+        when(mResource.getInteger(
+                R.integer.config_wifi_framework_wifi_score_good_rssi_threshold_5GHz))
+                .thenReturn(-57);
+        when(mResource.getInteger(
+                R.integer.config_wifi_framework_wifi_score_good_rssi_threshold_24GHz))
+                .thenReturn(-60);
     }
 
     private void setupWifiInfo() {
@@ -298,96 +311,6 @@ public class WifiNetworkSelectorTest {
     }
 
     /**
-     * No network selection if the currently connected on is already sufficient.
-     *
-     * WifiStateMachine is connected to a qualified (5G, secure, good RSSI) network.
-     * scanDetails contains a valid network.
-     * Perform a network seletion after the first one.
-     *
-     * Expected behavior: no network recommended by Network Selector
-     */
-    @Test
-    public void noNetworkSelectionWhenCurrentOneIsSufficient() {
-        String[] ssids = {"\"test1\""};
-        String[] bssids = {"6c:f3:7f:ae:8c:f3"};
-        int[] freqs = {5180};
-        String[] caps = {"[WPA2-EAP-CCMP][ESS]"};
-        int[] levels = {mThresholdQualifiedRssi5G + 8};
-        int[] securities = {SECURITY_PSK};
-
-        ScanDetailsAndWifiConfigs scanDetailsAndConfigs =
-                WifiNetworkSelectorTestUtil.setupScanDetailsAndConfigStore(ssids, bssids,
-                    freqs, caps, levels, securities, mWifiConfigManager, mClock);
-        List<ScanDetail> scanDetails = scanDetailsAndConfigs.getScanDetails();
-        HashSet<String> blacklist = new HashSet<String>();
-
-        // connect to test1
-        mWifiNetworkSelector.selectNetwork(scanDetails, blacklist, mWifiInfo, false, true, false);
-        when(mWifiInfo.getNetworkId()).thenReturn(0);
-        when(mWifiInfo.getBSSID()).thenReturn(bssids[0]);
-        when(mWifiInfo.is24GHz()).thenReturn(false);
-
-        when(mClock.getElapsedSinceBootMillis()).thenReturn(SystemClock.elapsedRealtime()
-                + WifiNetworkSelector.MINIMUM_NETWORK_SELECTION_INTERVAL_MS + 2000);
-
-        levels[0] = mThresholdQualifiedRssi5G + 20;
-        scanDetailsAndConfigs =
-                WifiNetworkSelectorTestUtil.setupScanDetailsAndConfigStore(ssids, bssids,
-                    freqs, caps, levels, securities, mWifiConfigManager, mClock);
-        scanDetails = scanDetailsAndConfigs.getScanDetails();
-
-        WifiConfiguration candidate = mWifiNetworkSelector.selectNetwork(scanDetails,
-                blacklist, mWifiInfo, true, false, false);
-        assertEquals("Expect null configuration", null, candidate);
-    }
-
-    /**
-     * New network selection is performed if the currently connected network
-     * band is 2G.
-     *
-     * WifiStateMachine is connected to a 2G network.
-     * scanDetails contains a valid networks.
-     * Perform a network seletion after the first one.
-     *
-     * Expected behavior: the first network is recommended by Network Selector
-     */
-    @Test
-    public void band2GNetworkIsNotSufficient() {
-        String[] ssids = {"\"test1\""};
-        String[] bssids = {"6c:f3:7f:ae:8c:f3"};
-        int[] freqs = {2470};
-        String[] caps = {"[WPA2-EAP-CCMP][ESS]"};
-        int[] levels = {mThresholdQualifiedRssi2G + 8};
-        int[] securities = {SECURITY_PSK};
-
-        ScanDetailsAndWifiConfigs scanDetailsAndConfigs =
-                WifiNetworkSelectorTestUtil.setupScanDetailsAndConfigStore(ssids, bssids,
-                    freqs, caps, levels, securities, mWifiConfigManager, mClock);
-        List<ScanDetail> scanDetails = scanDetailsAndConfigs.getScanDetails();
-        HashSet<String> blacklist = new HashSet<String>();
-        WifiConfiguration[] savedConfigs = scanDetailsAndConfigs.getWifiConfigs();
-
-        // connect to test1
-        mWifiNetworkSelector.selectNetwork(scanDetails, blacklist, mWifiInfo, false, true, false);
-        when(mWifiInfo.getNetworkId()).thenReturn(0);
-        when(mWifiInfo.getBSSID()).thenReturn(bssids[0]);
-        when(mWifiInfo.is24GHz()).thenReturn(true);
-
-        when(mClock.getElapsedSinceBootMillis()).thenReturn(SystemClock.elapsedRealtime()
-                + WifiNetworkSelector.MINIMUM_NETWORK_SELECTION_INTERVAL_MS + 2000);
-
-        // Do another network selection.
-        WifiConfiguration candidate = mWifiNetworkSelector.selectNetwork(scanDetails,
-                blacklist, mWifiInfo, true, false, false);
-
-        ScanResult chosenScanResult = scanDetails.get(0).getScanResult();
-        WifiConfigurationTestUtil.assertConfigurationEqual(savedConfigs[0], candidate);
-        WifiNetworkSelectorTestUtil.verifySelectedScanResult(mWifiConfigManager,
-                chosenScanResult, candidate);
-    }
-
-
-    /**
      * New network selection is performed if the currently connected network
      * is a open one.
      *
@@ -475,7 +398,6 @@ public class WifiNetworkSelectorTest {
                 blacklist, mWifiInfo, true, false, false);
 
         ScanResult chosenScanResult = scanDetails.get(0).getScanResult();
-        WifiConfigurationTestUtil.assertConfigurationEqual(savedConfigs[0], candidate);
         WifiNetworkSelectorTestUtil.verifySelectedScanResult(mWifiConfigManager,
                 chosenScanResult, candidate);
     }
@@ -657,4 +579,131 @@ public class WifiNetworkSelectorTest {
 
         WifiConfigurationTestUtil.assertConfigurationEqual(userChoice, candidate);
     }
+
+    /**
+     * Wifi network selector doesn't recommend any network if the currently connected 2.4Ghz
+     * network is high quality and no 5GHz networks are available
+     *
+     * WifiStateMachine is under connected state and 2.4GHz test1 is connected.
+     *
+     * Expected behavior: no network selection is performed
+     */
+    @Test
+    public void test2GhzQualifiedNo5GhzAvailable() {
+        // Do not perform selection on 2GHz if current network is good and no 5GHz available
+        testStayOrSwitch(mThresholdQualifiedRssi2G, false,
+                mThresholdQualifiedRssi2G + 10, false, false);
+    }
+
+    /**
+     * Wifi network selector performs network selection even when the 2Ghz network is high
+     * quality whenever 5Ghz networks are available.
+     *
+     * WifiStateMachine is under connected state and 2.4GHz test1 is connected.
+     * The scan results contain a 5Ghz network, which forces network selection.
+     * Test1 is not in the second scan results.
+     *
+     * Expected behavior: network selection is performed
+     */
+    @Test
+    public void test2GhzHighQuality5GhzAvailable() {
+        // When on 2GHz, even with "good" signal strength, run selection if 5GHz available
+        testStayOrSwitch(mThresholdQualifiedRssi2G, false,
+                mThresholdQualifiedRssi5G - 1, true, true);
+    }
+
+    /**
+     * Wifi network selector performs network selection on 2Ghz networks if the current network
+     * is not of high quality.
+     *
+     * WifiStateMachine is under connected state and 2.4GHz test1 is connected.
+     *
+     * Expected behavior: network selection is performed
+     */
+    @Test
+    public void test2GhzNotQualifiedOther2GhzAvailable() {
+        // Run Selection on 2Ghz networks when not qualified even if no 5GHz available
+        testStayOrSwitch(mThresholdQualifiedRssi2G - 1, false,
+                mThresholdQualifiedRssi2G - 10, false, true);
+    }
+
+    /**
+     * Wifi network selector performs network selection when connected to a 5Ghz network that
+     * has an insufficient RSSI.
+     *
+     * WifiStateMachine is under connected state and 5GHz test1 is connected.
+     *
+     * Expected behavior: network selection is performed
+     */
+    @Test
+    public void test5GhzNotQualifiedLowRssi() {
+        // Run Selection when the current 5Ghz network has low RSSI, regardless of what may
+        // be available. The second scan result is irrelevant.
+        testStayOrSwitch(mThresholdQualifiedRssi5G - 1, true,
+                mThresholdQualifiedRssi2G - 1, false, true);
+    }
+
+    /**
+     * Wifi network selector will not run selection when on a 5Ghz network that is of sufficent
+     * Quality (high-enough RSSI).
+     *
+     * WifiStateMachine is under connected state and 5GHz test1 is connected.
+     *
+     * Expected behavior: network selection is not performed
+     */
+    @Test
+    public void test5GhzQualified() {
+        // Connected to a high quality 5Ghz network, so the other result is irrelevant
+        testStayOrSwitch(mThresholdQualifiedRssi5G, true,
+                mThresholdQualifiedRssi5G + 10, true, false);
+    }
+
+    /**
+     * This is a meta-test that given two scan results of various types, will
+     * determine whether or not network selection should be performed.
+     *
+     * It sets up two networks, connects to the first, and then ensures that
+     * both are available in the scan results for the NetworkSelector.
+     */
+    private void testStayOrSwitch(int levelNetwork1, boolean is5GHzNetwork1,
+                int levelNetwork2, boolean is5GHzNetwork2, boolean shouldSelect) {
+        // Create an updated ScanDetails that includes a new network
+        String[] ssids = {"\"test1\"", "\"test2\""};
+        String[] bssids = {"6c:f3:7f:ae:8c:f3", "6c:f3:7f:ae:8c:f4"};
+        int[] freqs = new int[2];
+        freqs[0] = is5GHzNetwork1 ? 5180 : 2437;
+        freqs[1] = is5GHzNetwork2 ? 5180 : 2437;
+        String[] caps = {"[WPA2-EAP-CCMP][ESS]", "[WPA2-EAP-CCMP][ESS]"};
+        int[] levels = {levelNetwork1, levelNetwork2};
+        int[] securities = {SECURITY_PSK, SECURITY_PSK};
+
+        // Make a network selection to connect to test1.
+        ScanDetailsAndWifiConfigs scanDetailsAndConfigs =
+                WifiNetworkSelectorTestUtil.setupScanDetailsAndConfigStore(ssids, bssids,
+                    freqs, caps, levels, securities, mWifiConfigManager, mClock);
+        List<ScanDetail> scanDetails = scanDetailsAndConfigs.getScanDetails();
+        HashSet<String> blacklist = new HashSet<String>();
+        WifiConfiguration candidate = mWifiNetworkSelector.selectNetwork(scanDetails,
+                blacklist, mWifiInfo, false, true, false);
+
+        when(mWifiInfo.getNetworkId()).thenReturn(0);
+        when(mWifiInfo.getBSSID()).thenReturn(bssids[0]);
+        when(mWifiInfo.is24GHz()).thenReturn(!is5GHzNetwork1);
+        when(mWifiInfo.is5GHz()).thenReturn(is5GHzNetwork1);
+        when(mWifiInfo.getRssi()).thenReturn(levels[0]);
+        when(mClock.getElapsedSinceBootMillis()).thenReturn(SystemClock.elapsedRealtime()
+                + WifiNetworkSelector.MINIMUM_NETWORK_SELECTION_INTERVAL_MS + 2000);
+
+        candidate = mWifiNetworkSelector.selectNetwork(scanDetails, blacklist, mWifiInfo,
+                true, false, false);
+
+        if (!shouldSelect) {
+            assertEquals("Expect null configuration", null, candidate);
+        } else {
+            assertNotNull("Result should be not null", candidate);
+            ScanResult expectedResult = scanDetails.get(0).getScanResult();
+            WifiNetworkSelectorTestUtil.verifySelectedScanResult(mWifiConfigManager,
+                    expectedResult, candidate);
+        }
+    }
 }