package com.android.server.wifi.util;
import android.net.wifi.WifiConfiguration;
import android.net.wifi.WifiScanner;
import android.util.Log;
import com.android.server.wifi.WifiNative;
import java.util.ArrayList;
import java.util.Random;
/**
-
Provide utility functions for updating soft AP related configuration.
*/
public class ApConfigUtil {
private static final String TAG = “ApConfigUtil”;public static final int DEFAULT_AP_BAND = WifiConfiguration.AP_BAND_2GHZ;
public static final int DEFAULT_AP_CHANNEL = 6;/* Return code for updateConfiguration. */
public static final int SUCCESS = 0;
public static final int ERROR_NO_CHANNEL = 1;
public static final int ERROR_GENERIC = 2;/* Random number generator used for AP channel selection. */
private static final Random sRandom = new Random();/**
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Convert frequency to channel.
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@param frequency frequency to convert
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@return channel number associated with given frequency, -1 if no match
/
public static int convertFrequencyToChannel(int frequency) {
if (frequency >= 2412 && frequency <= 2472) {
return (frequency - 2412) / 5 + 1;
} else if (frequency == 2484) {
return 14;
} else if (frequency >= 5170 && frequency <= 5825) {
/ DFS is included. */
return (frequency - 5170) / 5 + 34;
}return -1;
}
/**
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Return a channel number for AP setup based on the frequency band.
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@param apBand 0 for 2GHz, 1 for 5GHz
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@param allowed2GChannels list of allowed 2GHz channels
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@param allowed5GFreqList list of allowed 5GHz frequencies
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@return a valid channel number on success, -1 on failure.
*/
public static int chooseApChannel(int apBand,
ArrayList allowed2GChannels,
int allowed5GFreqList) {
if (apBand != WifiConfiguration.AP_BAND_2GHZ
&& apBand != WifiConfiguration.AP_BAND_5GHZ) {
Log.e(TAG, "Invalid band: " + apBand);
return -1;
}if (apBand == WifiConfiguration.AP_BAND_2GHZ) {
/* Select a channel from 2GHz band. /
if (allowed2GChannels == null || allowed2GChannels.size() == 0) {
Log.d(TAG, “2GHz allowed channel list not specified”);
/ Use default channel. */
return DEFAULT_AP_CHANNEL;
}/* Pick a random channel. */ int index = sRandom.nextInt(allowed2GChannels.size()); return allowed2GChannels.get(index).intValue();}
/* 5G without DFS. /
if (allowed5GFreqList != null && allowed5GFreqList.length > 0) {
/ Pick a random channel from the list of supported channels. */
return convertFrequencyToChannel(
allowed5GFreqList[sRandom.nextInt(allowed5GFreqList.length)]);
}Log.e(TAG, “No available channels on 5GHz band”);
return -1;
}
/**
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Update AP band and channel based on the provided country code and band.
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This will also set
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@param wifiNative reference to WifiNative
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@param countryCode country code
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@param allowed2GChannels list of allowed 2GHz channels
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@param config configuration to update
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@return an integer result code
/
public static int updateApChannelConfig(WifiNative wifiNative,
String countryCode,
ArrayList allowed2GChannels,
WifiConfiguration config) {
/ Use default band and channel for device without HAL. */
if (!wifiNative.isHalStarted()) {
config.apBand = DEFAULT_AP_BAND;
config.apChannel = DEFAULT_AP_CHANNEL;
return SUCCESS;
}/* Country code is mandatory for 5GHz band. */
if (config.apBand == WifiConfiguration.AP_BAND_5GHZ
&& countryCode == null) {
Log.e(TAG, “5GHz band is not allowed without country code, use channel:153 for 5GHz AP”);
-