com/android/server/wifi/LegacyConnectedScore.java - platform/prebuilts/fullsdk/sources/android-28 - Git at Google

 /*
  * Copyright (C) 2017 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 package com.android.server.wifi;

 import android.content.Context;
 import android.net.NetworkAgent;
 import android.net.wifi.WifiConfiguration;
 import android.net.wifi.WifiInfo;

 import com.android.internal.R;

 /**
  * Class used to calculate scores for connected wifi networks and report it to the associated
  * network agent.
  */
 public class LegacyConnectedScore extends ConnectedScore {

     private static final int STARTING_SCORE = 56;

     private static final int SCAN_CACHE_VISIBILITY_MS = 12000;
     private static final int HOME_VISIBLE_NETWORK_MAX_COUNT = 6;
     private static final int SCAN_CACHE_COUNT_PENALTY = 2;
     private static final int MAX_SUCCESS_RATE_OF_STUCK_LINK = 3; // proportional to packets per sec
     private static final int MAX_STUCK_LINK_COUNT = 5;
     private static final int MAX_BAD_RSSI_COUNT = 7;
     private static final int BAD_RSSI_COUNT_PENALTY = 2;
     private static final int MAX_LOW_RSSI_COUNT = 1;
     private static final double MIN_TX_FAILURE_RATE_FOR_WORKING_LINK = 0.3;
     private static final int MIN_SUSTAINED_LINK_STUCK_COUNT = 1;
     private static final int LINK_STUCK_PENALTY = 2;
     private static final int BAD_LINKSPEED_PENALTY = 4;
     private static final int GOOD_LINKSPEED_BONUS = 4;

     // Device configs. The values are examples.
     private final int mThresholdMinimumRssi5;      // -82
     private final int mThresholdQualifiedRssi5;    // -70
     private final int mThresholdSaturatedRssi5;    // -57
     private final int mThresholdMinimumRssi24;     // -85
     private final int mThresholdQualifiedRssi24;   // -73
     private final int mThresholdSaturatedRssi24;   // -60
     private final int mBadLinkSpeed24;             //  6 Mbps
     private final int mBadLinkSpeed5;              // 12 Mbps
     private final int mGoodLinkSpeed24;            // 24 Mbps
     private final int mGoodLinkSpeed5;             // 36 Mbps

     private final WifiConfigManager mWifiConfigManager;
     private boolean mVerboseLoggingEnabled = false;

     private boolean mMultiBandScanResults;
     private boolean mIsHomeNetwork;
     private int mScore = 0;

     LegacyConnectedScore(Context context, WifiConfigManager wifiConfigManager, Clock clock) {
         super(clock);
         // Fetch all the device configs.
         mThresholdMinimumRssi5 = context.getResources().getInteger(
                 R.integer.config_wifi_framework_wifi_score_bad_rssi_threshold_5GHz);
         mThresholdQualifiedRssi5 = context.getResources().getInteger(
                 R.integer.config_wifi_framework_wifi_score_low_rssi_threshold_5GHz);
         mThresholdSaturatedRssi5 = context.getResources().getInteger(
                 R.integer.config_wifi_framework_wifi_score_good_rssi_threshold_5GHz);
         mThresholdMinimumRssi24 = context.getResources().getInteger(
                 R.integer.config_wifi_framework_wifi_score_bad_rssi_threshold_24GHz);
         mThresholdQualifiedRssi24 = context.getResources().getInteger(
                 R.integer.config_wifi_framework_wifi_score_low_rssi_threshold_24GHz);
         mThresholdSaturatedRssi24 = context.getResources().getInteger(
                 R.integer.config_wifi_framework_wifi_score_good_rssi_threshold_24GHz);
         mBadLinkSpeed24 = context.getResources().getInteger(
                 R.integer.config_wifi_framework_wifi_score_bad_link_speed_24);
         mBadLinkSpeed5 = context.getResources().getInteger(
                 R.integer.config_wifi_framework_wifi_score_bad_link_speed_5);
         mGoodLinkSpeed24 = context.getResources().getInteger(
                 R.integer.config_wifi_framework_wifi_score_good_link_speed_24);
         mGoodLinkSpeed5 = context.getResources().getInteger(
                 R.integer.config_wifi_framework_wifi_score_good_link_speed_5);

         mWifiConfigManager = wifiConfigManager;
     }

     @Override
     public void updateUsingWifiInfo(WifiInfo wifiInfo, long millis) {
         mMultiBandScanResults = multiBandScanResults(wifiInfo);
         mIsHomeNetwork = isHomeNetwork(wifiInfo);

         int rssiThreshBad = mThresholdMinimumRssi24;
         int rssiThreshLow = mThresholdQualifiedRssi24;

         if (wifiInfo.is5GHz() && !mMultiBandScanResults) {
             rssiThreshBad = mThresholdMinimumRssi5;
             rssiThreshLow = mThresholdQualifiedRssi5;
         }

         int rssi =  wifiInfo.getRssi();
         if (mIsHomeNetwork) {
             rssi += WifiConfiguration.HOME_NETWORK_RSSI_BOOST;
         }

         if ((wifiInfo.txBadRate >= 1)
                 && (wifiInfo.txSuccessRate < MAX_SUCCESS_RATE_OF_STUCK_LINK)
                 && rssi < rssiThreshLow) {
             // Link is stuck
             if (wifiInfo.linkStuckCount < MAX_STUCK_LINK_COUNT) {
                 wifiInfo.linkStuckCount += 1;
             }
         } else if (wifiInfo.txBadRate < MIN_TX_FAILURE_RATE_FOR_WORKING_LINK) {
             if (wifiInfo.linkStuckCount > 0) {
                 wifiInfo.linkStuckCount -= 1;
             }
         }

         if (rssi < rssiThreshBad) {
             if (wifiInfo.badRssiCount < MAX_BAD_RSSI_COUNT) {
                 wifiInfo.badRssiCount += 1;
             }
         } else if (rssi < rssiThreshLow) {
             wifiInfo.lowRssiCount = MAX_LOW_RSSI_COUNT; // Dont increment the lowRssi count above 1
             if (wifiInfo.badRssiCount > 0) {
                 // Decrement bad Rssi count
                 wifiInfo.badRssiCount -= 1;
             }
         } else {
             wifiInfo.badRssiCount = 0;
             wifiInfo.lowRssiCount = 0;
         }

         // Ugh, we need to finish the score calculation while we have wifiInfo
         mScore = calculateScore(wifiInfo);

     }

     @Override
     public void updateUsingRssi(int rssi, long millis, double standardDeviation) {
         // This scorer needs more than just the RSSI. Just ignore.
     }

     @Override
     public int generateScore() {
         return mScore;
     }

     @Override
     public void reset() {
         mScore = 0;
     }

     /**
      * Calculates a score based on the current state and wifiInfo
      */
     private int calculateScore(WifiInfo wifiInfo) {
         int score = STARTING_SCORE;

         int rssiThreshSaturated = mThresholdSaturatedRssi24;
         int linkspeedThreshBad = mBadLinkSpeed24;
         int linkspeedThreshGood = mGoodLinkSpeed24;

         if (wifiInfo.is5GHz()) {
             if (!mMultiBandScanResults) {
                 rssiThreshSaturated = mThresholdSaturatedRssi5;
             }
             linkspeedThreshBad = mBadLinkSpeed5;
             linkspeedThreshGood = mGoodLinkSpeed5;
         }

         int rssi =  wifiInfo.getRssi();
         if (mIsHomeNetwork) {
             rssi += WifiConfiguration.HOME_NETWORK_RSSI_BOOST;
         }

         int linkSpeed = wifiInfo.getLinkSpeed();

         if (wifiInfo.linkStuckCount > MIN_SUSTAINED_LINK_STUCK_COUNT) {
             // Once link gets stuck for more than 3 seconds, start reducing the score
             score = score - LINK_STUCK_PENALTY * (wifiInfo.linkStuckCount - 1);
         }

         if (linkSpeed < linkspeedThreshBad) {
             score -= BAD_LINKSPEED_PENALTY;
         } else if ((linkSpeed >= linkspeedThreshGood) && (wifiInfo.txSuccessRate > 5)) {
             score += GOOD_LINKSPEED_BONUS; // So as bad rssi alone doesn't kill us
         }

         score -= wifiInfo.badRssiCount * BAD_RSSI_COUNT_PENALTY + wifiInfo.lowRssiCount;

         if (rssi >= rssiThreshSaturated) score += 5;

         if (score > NetworkAgent.WIFI_BASE_SCORE) score = NetworkAgent.WIFI_BASE_SCORE;
         if (score < 0) score = 0;

         return score;
     }

     /**
      * Determines if we can see both 2.4GHz and 5GHz for current config
      */
     private boolean multiBandScanResults(WifiInfo wifiInfo) {
         WifiConfiguration currentConfiguration =
                 mWifiConfigManager.getConfiguredNetwork(wifiInfo.getNetworkId());
         if (currentConfiguration == null) return false;
         ScanDetailCache scanDetailCache =
                 mWifiConfigManager.getScanDetailCacheForNetwork(wifiInfo.getNetworkId());
         if (scanDetailCache == null) return false;
         // Nasty that we change state here...
         currentConfiguration.setVisibility(scanDetailCache.getVisibility(SCAN_CACHE_VISIBILITY_MS));
         if (currentConfiguration.visibility == null) return false;
         if (currentConfiguration.visibility.rssi24 == WifiConfiguration.INVALID_RSSI) return false;
         if (currentConfiguration.visibility.rssi5 == WifiConfiguration.INVALID_RSSI) return false;
         // N.B. this does not do exactly what is claimed!
         if (currentConfiguration.visibility.rssi24
                 >= currentConfiguration.visibility.rssi5 - SCAN_CACHE_COUNT_PENALTY) {
             return true;
         }
         return false;
     }

     /**
      * Decides whether the current network is a "home" network
      */
     private boolean isHomeNetwork(WifiInfo wifiInfo) {
         WifiConfiguration currentConfiguration =
                 mWifiConfigManager.getConfiguredNetwork(wifiInfo.getNetworkId());
         if (currentConfiguration == null) return false;
         // This seems like it will only return true for really old routers!
         if (currentConfiguration.allowedKeyManagement.cardinality() != 1) return false;
         if (!currentConfiguration.allowedKeyManagement.get(WifiConfiguration.KeyMgmt.WPA_PSK)) {
             return false;
         }
         ScanDetailCache scanDetailCache =
                 mWifiConfigManager.getScanDetailCacheForNetwork(wifiInfo.getNetworkId());
         if (scanDetailCache == null) return false;
         if (scanDetailCache.size() <= HOME_VISIBLE_NETWORK_MAX_COUNT) {
             return true;
         }
         return false;
     }
 }
	/*
	* Copyright (C) 2017 The Android Open Source Project
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	package com.android.server.wifi;

	import android.content.Context;
	import android.net.NetworkAgent;
	import android.net.wifi.WifiConfiguration;
	import android.net.wifi.WifiInfo;

	import com.android.internal.R;

	/**
	* Class used to calculate scores for connected wifi networks and report it to the associated
	* network agent.
	*/
	public class LegacyConnectedScore extends ConnectedScore {

	private static final int STARTING_SCORE = 56;

	private static final int SCAN_CACHE_VISIBILITY_MS = 12000;
	private static final int HOME_VISIBLE_NETWORK_MAX_COUNT = 6;
	private static final int SCAN_CACHE_COUNT_PENALTY = 2;
	private static final int MAX_SUCCESS_RATE_OF_STUCK_LINK = 3; // proportional to packets per sec
	private static final int MAX_STUCK_LINK_COUNT = 5;
	private static final int MAX_BAD_RSSI_COUNT = 7;
	private static final int BAD_RSSI_COUNT_PENALTY = 2;
	private static final int MAX_LOW_RSSI_COUNT = 1;
	private static final double MIN_TX_FAILURE_RATE_FOR_WORKING_LINK = 0.3;
	private static final int MIN_SUSTAINED_LINK_STUCK_COUNT = 1;
	private static final int LINK_STUCK_PENALTY = 2;
	private static final int BAD_LINKSPEED_PENALTY = 4;
	private static final int GOOD_LINKSPEED_BONUS = 4;

	// Device configs. The values are examples.
	private final int mThresholdMinimumRssi5; // -82
	private final int mThresholdQualifiedRssi5; // -70
	private final int mThresholdSaturatedRssi5; // -57
	private final int mThresholdMinimumRssi24; // -85
	private final int mThresholdQualifiedRssi24; // -73
	private final int mThresholdSaturatedRssi24; // -60
	private final int mBadLinkSpeed24; // 6 Mbps
	private final int mBadLinkSpeed5; // 12 Mbps
	private final int mGoodLinkSpeed24; // 24 Mbps
	private final int mGoodLinkSpeed5; // 36 Mbps

	private final WifiConfigManager mWifiConfigManager;
	private boolean mVerboseLoggingEnabled = false;

	private boolean mMultiBandScanResults;
	private boolean mIsHomeNetwork;
	private int mScore = 0;

	LegacyConnectedScore(Context context, WifiConfigManager wifiConfigManager, Clock clock) {
	super(clock);
	// Fetch all the device configs.
	mThresholdMinimumRssi5 = context.getResources().getInteger(
	R.integer.config_wifi_framework_wifi_score_bad_rssi_threshold_5GHz);
	mThresholdQualifiedRssi5 = context.getResources().getInteger(
	R.integer.config_wifi_framework_wifi_score_low_rssi_threshold_5GHz);
	mThresholdSaturatedRssi5 = context.getResources().getInteger(
	R.integer.config_wifi_framework_wifi_score_good_rssi_threshold_5GHz);
	mThresholdMinimumRssi24 = context.getResources().getInteger(
	R.integer.config_wifi_framework_wifi_score_bad_rssi_threshold_24GHz);
	mThresholdQualifiedRssi24 = context.getResources().getInteger(
	R.integer.config_wifi_framework_wifi_score_low_rssi_threshold_24GHz);
	mThresholdSaturatedRssi24 = context.getResources().getInteger(
	R.integer.config_wifi_framework_wifi_score_good_rssi_threshold_24GHz);
	mBadLinkSpeed24 = context.getResources().getInteger(
	R.integer.config_wifi_framework_wifi_score_bad_link_speed_24);
	mBadLinkSpeed5 = context.getResources().getInteger(
	R.integer.config_wifi_framework_wifi_score_bad_link_speed_5);
	mGoodLinkSpeed24 = context.getResources().getInteger(
	R.integer.config_wifi_framework_wifi_score_good_link_speed_24);
	mGoodLinkSpeed5 = context.getResources().getInteger(
	R.integer.config_wifi_framework_wifi_score_good_link_speed_5);

	mWifiConfigManager = wifiConfigManager;
	}

	@Override
	public void updateUsingWifiInfo(WifiInfo wifiInfo, long millis) {
	mMultiBandScanResults = multiBandScanResults(wifiInfo);
	mIsHomeNetwork = isHomeNetwork(wifiInfo);

	int rssiThreshBad = mThresholdMinimumRssi24;
	int rssiThreshLow = mThresholdQualifiedRssi24;

	if (wifiInfo.is5GHz() && !mMultiBandScanResults) {
	rssiThreshBad = mThresholdMinimumRssi5;
	rssiThreshLow = mThresholdQualifiedRssi5;
	}

	int rssi = wifiInfo.getRssi();
	if (mIsHomeNetwork) {
	rssi += WifiConfiguration.HOME_NETWORK_RSSI_BOOST;
	}

	if ((wifiInfo.txBadRate >= 1)
	&& (wifiInfo.txSuccessRate < MAX_SUCCESS_RATE_OF_STUCK_LINK)
	&& rssi < rssiThreshLow) {
	// Link is stuck
	if (wifiInfo.linkStuckCount < MAX_STUCK_LINK_COUNT) {
	wifiInfo.linkStuckCount += 1;
	}
	} else if (wifiInfo.txBadRate < MIN_TX_FAILURE_RATE_FOR_WORKING_LINK) {
	if (wifiInfo.linkStuckCount > 0) {
	wifiInfo.linkStuckCount -= 1;
	}
	}

	if (rssi < rssiThreshBad) {
	if (wifiInfo.badRssiCount < MAX_BAD_RSSI_COUNT) {
	wifiInfo.badRssiCount += 1;
	}
	} else if (rssi < rssiThreshLow) {
	wifiInfo.lowRssiCount = MAX_LOW_RSSI_COUNT; // Dont increment the lowRssi count above 1
	if (wifiInfo.badRssiCount > 0) {
	// Decrement bad Rssi count
	wifiInfo.badRssiCount -= 1;
	}
	} else {
	wifiInfo.badRssiCount = 0;
	wifiInfo.lowRssiCount = 0;
	}

	// Ugh, we need to finish the score calculation while we have wifiInfo
	mScore = calculateScore(wifiInfo);

	}

	@Override
	public void updateUsingRssi(int rssi, long millis, double standardDeviation) {
	// This scorer needs more than just the RSSI. Just ignore.
	}

	@Override
	public int generateScore() {
	return mScore;
	}

	@Override
	public void reset() {
	mScore = 0;
	}

	/**
	* Calculates a score based on the current state and wifiInfo
	*/
	private int calculateScore(WifiInfo wifiInfo) {
	int score = STARTING_SCORE;

	int rssiThreshSaturated = mThresholdSaturatedRssi24;
	int linkspeedThreshBad = mBadLinkSpeed24;
	int linkspeedThreshGood = mGoodLinkSpeed24;

	if (wifiInfo.is5GHz()) {
	if (!mMultiBandScanResults) {
	rssiThreshSaturated = mThresholdSaturatedRssi5;
	}
	linkspeedThreshBad = mBadLinkSpeed5;
	linkspeedThreshGood = mGoodLinkSpeed5;
	}

	int rssi = wifiInfo.getRssi();
	if (mIsHomeNetwork) {
	rssi += WifiConfiguration.HOME_NETWORK_RSSI_BOOST;
	}

	int linkSpeed = wifiInfo.getLinkSpeed();

	if (wifiInfo.linkStuckCount > MIN_SUSTAINED_LINK_STUCK_COUNT) {
	// Once link gets stuck for more than 3 seconds, start reducing the score
	score = score - LINK_STUCK_PENALTY * (wifiInfo.linkStuckCount - 1);
	}

	if (linkSpeed < linkspeedThreshBad) {
	score -= BAD_LINKSPEED_PENALTY;
	} else if ((linkSpeed >= linkspeedThreshGood) && (wifiInfo.txSuccessRate > 5)) {
	score += GOOD_LINKSPEED_BONUS; // So as bad rssi alone doesn't kill us
	}

	score -= wifiInfo.badRssiCount * BAD_RSSI_COUNT_PENALTY + wifiInfo.lowRssiCount;

	if (rssi >= rssiThreshSaturated) score += 5;

	if (score > NetworkAgent.WIFI_BASE_SCORE) score = NetworkAgent.WIFI_BASE_SCORE;
	if (score < 0) score = 0;

	return score;
	}

	/**
	* Determines if we can see both 2.4GHz and 5GHz for current config
	*/
	private boolean multiBandScanResults(WifiInfo wifiInfo) {
	WifiConfiguration currentConfiguration =
	mWifiConfigManager.getConfiguredNetwork(wifiInfo.getNetworkId());
	if (currentConfiguration == null) return false;
	ScanDetailCache scanDetailCache =
	mWifiConfigManager.getScanDetailCacheForNetwork(wifiInfo.getNetworkId());
	if (scanDetailCache == null) return false;
	// Nasty that we change state here...
	currentConfiguration.setVisibility(scanDetailCache.getVisibility(SCAN_CACHE_VISIBILITY_MS));
	if (currentConfiguration.visibility == null) return false;
	if (currentConfiguration.visibility.rssi24 == WifiConfiguration.INVALID_RSSI) return false;
	if (currentConfiguration.visibility.rssi5 == WifiConfiguration.INVALID_RSSI) return false;
	// N.B. this does not do exactly what is claimed!
	if (currentConfiguration.visibility.rssi24
	>= currentConfiguration.visibility.rssi5 - SCAN_CACHE_COUNT_PENALTY) {
	return true;
	}
	return false;
	}

	/**
	* Decides whether the current network is a "home" network
	*/
	private boolean isHomeNetwork(WifiInfo wifiInfo) {
	WifiConfiguration currentConfiguration =
	mWifiConfigManager.getConfiguredNetwork(wifiInfo.getNetworkId());
	if (currentConfiguration == null) return false;
	// This seems like it will only return true for really old routers!
	if (currentConfiguration.allowedKeyManagement.cardinality() != 1) return false;
	if (!currentConfiguration.allowedKeyManagement.get(WifiConfiguration.KeyMgmt.WPA_PSK)) {
	return false;
	}
	ScanDetailCache scanDetailCache =
	mWifiConfigManager.getScanDetailCacheForNetwork(wifiInfo.getNetworkId());
	if (scanDetailCache == null) return false;
	if (scanDetailCache.size() <= HOME_VISIBLE_NETWORK_MAX_COUNT) {
	return true;
	}
	return false;
	}
	}