<?php

require_once 'includes/wifi_functions.php';
require_once 'includes/config.php';

getWifiInterface();

/**
 * Initialize hostapd values, display interface
 *
 */
function DisplayHostAPDConfig()
{
    $status = new \RaspAP\Messages\StatusMessage;
    $system = new \RaspAP\System\Sysinfo;
    $operatingSystem = $system->operatingSystem();
    $arrConfig = array();
    $arr80211Standard = [
        'a' => '802.11a - 5 GHz',
        'b' => '802.11b - 2.4 GHz',
        'g' => '802.11g - 2.4 GHz',
        'n' => '802.11n - 2.4 GHz',
        'ac' => '802.11ac - 5 GHz'
    ];
    $languageCode = strtok($_SESSION['locale'], '_');
    $countryCodes = getCountryCodes($languageCode);

    $arrSecurity = array(1 => 'WPA', 2 => 'WPA2', 3 => 'WPA+WPA2', 'none' => _("None"));
    $arrEncType = array('TKIP' => 'TKIP', 'CCMP' => 'CCMP', 'TKIP CCMP' => 'TKIP+CCMP');
    $arrTxPower = getDefaultNetOpts('txpower','dbm');
    $managedModeEnabled = false;
    exec("ip -o link show | awk -F': ' '{print $2}'", $interfaces);
    sort($interfaces);

    $reg_domain = shell_exec("iw reg get | grep -o 'country [A-Z]\{2\}' | awk 'NR==1{print $2}'");

    $cmd = "iw dev ".$_SESSION['ap_interface']." info | awk '$1==\"txpower\" {print $2}'";
    exec($cmd, $txpower);
    $txpower = intval($txpower[0]);

    if (isset($_POST['interface'])) {
        $interface = escapeshellarg($_POST['interface']);
    }
    if (!RASPI_MONITOR_ENABLED) {
        if (isset($_POST['SaveHostAPDSettings'])) {
            SaveHostAPDConfig($arrSecurity, $arrEncType, $arr80211Standard, $interfaces, $reg_domain, $status);
        }
    }
    $arrHostapdConf = parse_ini_file(RASPI_CONFIG.'/hostapd.ini');

    if (!RASPI_MONITOR_ENABLED) {
         if (isset($_POST['StartHotspot']) || isset($_POST['RestartHotspot'])) {
            $status->addMessage('Attempting to start hotspot', 'info');
            if ($arrHostapdConf['BridgedEnable'] == 1) {
                exec('sudo '.RASPI_CONFIG.'/hostapd/servicestart.sh --interface br0 --seconds 2', $return);
            } elseif ($arrHostapdConf['WifiAPEnable'] == 1) {
                exec('sudo '.RASPI_CONFIG.'/hostapd/servicestart.sh --interface uap0 --seconds 2', $return);
            } else {
                exec('sudo '.RASPI_CONFIG.'/hostapd/servicestart.sh --seconds 2', $return);
            }
            foreach ($return as $line) {
                $status->addMessage($line, 'info');
            }
        } elseif (isset($_POST['StopHotspot'])) {
            $status->addMessage('Attempting to stop hotspot', 'info');
            exec('sudo /bin/systemctl stop hostapd.service', $return);
            foreach ($return as $line) {
                $status->addMessage($line, 'info');
            }
        }
    }
    exec('cat '. RASPI_HOSTAPD_CONFIG, $hostapdconfig);
    if (isset($_SESSION['wifi_client_interface'])) {
        exec('iwgetid '.$_SESSION['wifi_client_interface']. ' -r', $wifiNetworkID);
        if (!empty($wifiNetworkID[0])) {
            $managedModeEnabled = true;
        }
    }
    $hostapdstatus = $system->hostapdStatus();
    $serviceStatus = $hostapdstatus[0] == 0 ? "down" : "up";

    foreach ($hostapdconfig as $hostapdconfigline) {
        if (strlen($hostapdconfigline) === 0) {
            continue;
        }
        if ($hostapdconfigline[0] != "#") {
            $arrLine = explode("=", $hostapdconfigline);
            $arrConfig[$arrLine[0]]=$arrLine[1];
        }
    };
    // assign beacon_int boolean if value is set
    if (isset($arrConfig['beacon_int'])) {
        $arrConfig['beacon_interval_bool'] = 1;
    }
    // assign disassoc_low_ack boolean if value is set
    if (isset($arrConfig['disassoc_low_ack'])) {
        $arrConfig['disassoc_low_ack_bool'] = 1;
    } else {
        $arrConfig['disassoc_low_ack_bool'] = 0;
    }

    // assign country_code from iw reg if not set in config
    if (empty($arrConfig['country_code']) && isset($country_code[0])) {
        $arrConfig['country_code'] = $country_code[0];
    }

    // set txpower with iw if value is non-default ('auto')
    if (isset($_POST['txpower'])) {
        if ($_POST['txpower'] != 'auto') {
            $txpower = intval($_POST['txpower']);
            $sdBm = $txpower * 100;
            exec('sudo /sbin/iw dev '.$interface.' set txpower fixed '.$sdBm, $return);
            $status->addMessage('Setting transmit power to '.$_POST['txpower'].' dBm.', 'success');
            $txpower = $_POST['txpower'];
        } elseif ($_POST['txpower'] == 'auto') {
            exec('sudo /sbin/iw dev '.$interface.' set txpower auto', $return);
            $status->addMessage('Setting transmit power to '.$_POST['txpower'].'.', 'success');
            $txpower = $_POST['txpower'];
        }
    }

    $selectedHwMode = $arrConfig['hw_mode'];
    if (isset($arrConfig['ieee80211n'])) {
        if (strval($arrConfig['ieee80211n']) === '1') {
            $selectedHwMode = 'n';
        }
    }
    if (isset($arrConfig['ieee80211ac'])) {
        if (strval($arrConfig['ieee80211ac']) === '1') {
            $selectedHwMode = 'ac';
        }
    }
    if (isset($arrConfig['ieee80211w'])) {
        if (strval($arrConfig['ieee80211w']) === '2') {
            $selectedHwMode = 'w';
        }
    }

    exec('sudo /bin/chmod o+r '.RASPI_HOSTAPD_LOG);
    $logdata = getLogLimited(RASPI_HOSTAPD_LOG);

    echo renderTemplate(
        "hostapd", compact(
            "status",
            "serviceStatus",
            "hostapdstatus",
            "managedModeEnabled",
            "interfaces",
            "arrConfig",
            "arr80211Standard",
            "selectedHwMode",
            "arrSecurity",
            "arrEncType",
            "arrTxPower",
            "txpower",
            "arrHostapdConf",
            "operatingSystem",
            "selectedHwMode",
            "countryCodes",
            "logdata"
        )
    );
}

/**
 * Validate user input, save configs for hostapd, dnsmasq & dhcp
 *
 * @param array $wpa_array
 * @param array $enc_types
 * @param array $modes
 * @param string $interface
 * @param string $reg_domain
 * @param object $status
 * @return boolean
 */
function SaveHostAPDConfig($wpa_array, $enc_types, $modes, $interfaces, $reg_domain, $status)
{
    // It should not be possible to send bad data for these fields. 
    // If wpa fields are absent, return false and log securely.
    if (!(array_key_exists($_POST['wpa'], $wpa_array) 
        && array_key_exists($_POST['wpa_pairwise'], $enc_types) 
        && array_key_exists($_POST['hw_mode'], $modes))
    ) {
        $err  = "Attempting to set hostapd config with wpa='".escapeshellarg($_POST['wpa']);
        $err .= "', wpa_pairwise='".$escapeshellarg(_POST['wpa_pairwise']);
        $err .= "and hw_mode='".$escapeshellarg(_POST['hw_mode'])."'";
        error_log($err);
        return false;
    }
    // Validate input
    $good_input = true;

    if (!filter_var($_POST['channel'], FILTER_VALIDATE_INT)) {
        $status->addMessage('Attempting to set channel to invalid number.', 'danger');
        $good_input = false;
    }
    if (intval($_POST['channel']) < 1 || intval($_POST['channel']) > RASPI_5GHZ_CHANNEL_MAX) {
        $status->addMessage('Attempting to set channel outside of permitted range', 'danger');
        $good_input = false;
    }
    $arrHostapdConf = parse_ini_file('/etc/raspap/hostapd.ini');

    // Check for Bridged AP mode checkbox
    $bridgedEnable = 0;
    if ($arrHostapdConf['BridgedEnable'] == 0) {
        if (isset($_POST['bridgedEnable'])) {
            $bridgedEnable = 1;
        }
    } else {
        if (isset($_POST['bridgedEnable'])) {
            $bridgedEnable = 1;
        }
    }
    // Check for WiFi client AP mode checkbox
    $wifiAPEnable = 0;
    if ($bridgedEnable == 0) {  // enable client mode actions when not bridged
        if ($arrHostapdConf['WifiAPEnable'] == 0) {
            if (isset($_POST['wifiAPEnable'])) {
                $wifiAPEnable = 1;
            }
        } else {
            if (isset($_POST['wifiAPEnable'])) {
                $wifiAPEnable = 1;
            }
        }
    }
    // Check for Logfile output checkbox
    $logEnable = 0;
    if ($arrHostapdConf['LogEnable'] == 0) {
        if (isset($_POST['logEnable'])) {
            $logEnable = 1;
            exec('sudo '.RASPI_CONFIG.'/hostapd/enablelog.sh');
        } else {
            exec('sudo '.RASPI_CONFIG.'/hostapd/disablelog.sh');
        }
    } else {
        if (isset($_POST['logEnable'])) {
            $logEnable = 1;
            exec('sudo '.RASPI_CONFIG.'/hostapd/enablelog.sh');
        } else {
            exec('sudo '.RASPI_CONFIG.'/hostapd/disablelog.sh');
        }
    }
    // set AP interface default, override for ap-sta & bridged options
    $ap_iface = $_POST['interface']; // the hostap AP interface
    $cli_iface = $_POST['interface']; // the wifi client interface
    $session_iface = $_POST['interface']; // the interface that the UI needs to monitor for data usage etc.
    if ($wifiAPEnable) { // for AP-STA we monitor the uap0 interface, which is always the ap interface.
        $ap_iface = 'uap0';
        $session_iface = 'uap0';
    }
    if ($bridgedEnable) { // for bridged mode we monitor the bridge, but keep the selected interface as AP.
        $session_iface = 'br0';
        $cli_iface = 'br0';
    }

    // persist user options to /etc/raspap
    $cfg = [];
    $cfg['WifiInterface'] = $ap_iface;
    $cfg['LogEnable'] = $logEnable;
    // Save previous Client mode status when Bridged
    $cfg['WifiAPEnable'] = ($bridgedEnable == 1 ? $arrHostapdConf['WifiAPEnable'] : $wifiAPEnable);
    $cfg['BridgedEnable'] = $bridgedEnable;
    $cfg['WifiManaged'] = $cli_iface;
    write_php_ini($cfg, RASPI_CONFIG.'/hostapd.ini');
    $_SESSION['ap_interface'] = $session_iface;

    // Verify input
    if (empty($_POST['ssid']) || strlen($_POST['ssid']) > 32) {
        $status->addMessage('SSID must be between 1 and 32 characters', 'danger');
        $good_input = false;
    }

    # NB: A pass-phrase is a sequence of between 8 and 63 ASCII-encoded characters (IEEE Std. 802.11i-2004)
    # Each character in the pass-phrase must have an encoding in the range of 32 to 126 (decimal). (IEEE Std. 802.11i-2004, Annex H.4.1)
    if ($_POST['wpa'] !== 'none' && (strlen($_POST['wpa_passphrase']) < 8 || strlen($_POST['wpa_passphrase']) > 63)) {
        $status->addMessage('WPA passphrase must be between 8 and 63 characters', 'danger');
        $good_input = false;
    } elseif (!ctype_print($_POST['wpa_passphrase'])) {
        $status->addMessage('WPA passphrase must be comprised of printable ASCII characters', 'danger');
        $good_input = false;
    }

    if (isset($_POST['hiddenSSID'])) {
        if (!is_int((int)$_POST['hiddenSSID'])) {
            $status->addMessage('Parameter hiddenSSID not a number.', 'danger');
            $good_input = false;
        } elseif ((int)$_POST['hiddenSSID'] < 0 || (int)$_POST['hiddenSSID'] >= 3) {
            $status->addMessage('Parameter hiddenSSID contains invalid configuratie value.', 'danger');
            $good_input = false;
        } else {
            $ignore_broadcast_ssid = $_POST['hiddenSSID'];
        }
    } else {
        $ignore_broadcast_ssid = '0';
    }

    if (! in_array($_POST['interface'], $interfaces)) {
        $status->addMessage('Unknown interface '.htmlspecialchars($_POST['interface'], ENT_QUOTES), 'danger');
        $good_input = false;
    }
    if (strlen($_POST['country_code']) !== 0 && strlen($_POST['country_code']) != 2) {
        $status->addMessage('Country code must be blank or two characters', 'danger');
        $good_input = false;
    } else {
        $country_code = $_POST['country_code'];
    }
    if (isset($_POST['beaconintervalEnable'])) {
        if (!is_numeric($_POST['beacon_interval'])) {
            $status->addMessage('Beacon interval must be a numeric value', 'danger');
            $good_input = false;
        } elseif ($_POST['beacon_interval'] < 15 || $_POST['beacon_interval'] > 65535) {
            $status->addMessage('Beacon interval must be between 15 and 65535', 'danger');
            $good_input = false;
        }
    }
    $_POST['max_num_sta'] = (int) $_POST['max_num_sta'];
    $_POST['max_num_sta'] = $_POST['max_num_sta'] > 2007 ? 2007 : $_POST['max_num_sta'];
    $_POST['max_num_sta'] = $_POST['max_num_sta'] < 1 ? null : $_POST['max_num_sta'];

    if ($good_input) {
        $return = updateHostapdConfig($ignore_broadcast_ssid,$wifiAPEnable,$bridgedEnable);

        if (trim($country_code) != trim($reg_domain)) {
            $return = iwRegSet($country_code, $status);
        }

        // Fetch dhcp-range, lease time from system config
        $syscfg = parse_ini_file(RASPI_DNSMASQ_PREFIX.$ap_iface.'.conf', false, INI_SCANNER_RAW);

        if ($wifiAPEnable == 1) {
            // Enable uap0 configuration for ap-sta mode
            // Set dhcp-range from system config, fallback to default if undefined
            $dhcp_range = ($syscfg['dhcp-range'] == '') ? getDefaultNetValue('dnsmasq','uap0','dhcp-range') : $syscfg['dhcp-range'];
            $config = [ '# RaspAP uap0 configuration' ];
            $config[] = 'interface=lo,uap0               # Enable uap0 interface for wireless client AP mode';
            $config[] = 'bind-dynamic                    # Hybrid between --bind-interfaces and default';
            $config[] = 'server=8.8.8.8                  # Forward DNS requests to Google DNS';
            $config[] = 'domain-needed                   # Don\'t forward short names';
            $config[] = 'bogus-priv                      # Never forward addresses in the non-routed address spaces';
            $config[] = 'dhcp-range='.$dhcp_range;
            if (!empty($syscfg['dhcp-option'])) {
                $config[] = 'dhcp-option='.$syscfg['dhcp-option'];
            }
            $config[] = PHP_EOL;
            scanConfigDir('/etc/dnsmasq.d/','uap0',$status);
            $config = join(PHP_EOL, $config);
            file_put_contents("/tmp/dnsmasqdata", $config);
            system('sudo cp /tmp/dnsmasqdata '.RASPI_DNSMASQ_PREFIX.$ap_iface.'.conf', $return);
        } elseif ($bridgedEnable !==1) {
            $dhcp_range = ($syscfg['dhcp-range'] =='') ? getDefaultNetValue('dnsmasq',$ap_iface,'dhcp-range') : $syscfg['dhcp-range'];
            $config = [ '# RaspAP '.$_POST['interface'].' configuration' ];
            $config[] = 'interface='.$_POST['interface'];
            $config[] = 'domain-needed';
            $config[] = 'dhcp-range='.$dhcp_range;
            if (!empty($syscfg['dhcp-option'])) {
                $config[] = 'dhcp-option='.$syscfg['dhcp-option'];
            }
            $config[] = PHP_EOL;
            $config = join(PHP_EOL, $config);
            file_put_contents("/tmp/dnsmasqdata", $config);
            system('sudo cp /tmp/dnsmasqdata '.RASPI_DNSMASQ_PREFIX.$ap_iface.'.conf', $return);
        }

        // Set dhcp values from system config, fallback to default if undefined
        $jsonData = json_decode(getNetConfig($ap_iface), true);
        $ip_address = ($jsonData['StaticIP'] == '') ? getDefaultNetValue('dhcp',$ap_iface,'static ip_address') : $jsonData['StaticIP'];
        $domain_name_server = ($jsonData['StaticDNS'] =='') ? getDefaultNetValue('dhcp',$ap_iface,'static domain_name_server') : $jsonData['StaticDNS'];
        $routers = ($jsonData['StaticRouters'] == '') ? getDefaultNetValue('dhcp',$ap_iface,'static routers') : $jsonData['StaticRouters'];
        $netmask = ($jsonData['SubnetMask'] == '' || $jsonData['SubnetMask'] == '0.0.0.0') ? getDefaultNetValue('dhcp',$ap_iface,'subnetmask') : $jsonData['SubnetMask'];
        if (isset($ip_address) && !preg_match('/.*\/\d+/', $ip_address)) {
            $ip_address.='/'.mask2cidr($netmask);
        }

        if ($bridgedEnable == 1) {
            $config = array_keys(getDefaultNetOpts('dhcp','options'));
            $config[] = PHP_EOL.'# RaspAP br0 configuration';
            $config[] = 'denyinterfaces eth0 wlan0';
            $config[] = 'interface br0';
            $config[] = PHP_EOL;
        } elseif ($wifiAPEnable == 1) {
            $config = array_keys(getDefaultNetOpts('dhcp','options'));
            $config[] = PHP_EOL.'# RaspAP uap0 configuration';
            $config[] = 'interface uap0';
            $config[] = 'static ip_address='.$ip_address;
            $config[] = 'nohook wpa_supplicant';
            $config[] = PHP_EOL;
        } else {
            $def_ip = array();
            $config = [ '# RaspAP '.$ap_iface.' configuration' ];
            $config[] = 'interface '.$ap_iface;
            $config[] = 'static ip_address='.$ip_address;
            $config[] = 'static routers='.$routers;
            $config[] = 'static domain_name_server='.$domain_name_server;
            if (! is_null($jsonData['Metric'])) { $config[] = 'metric '.$jsonData['Metric']; }
        }
        $dhcp_cfg = file_get_contents(RASPI_DHCPCD_CONFIG);

        $skip_dhcp = false;
        if (preg_match('/wlan[2-9]\d*|wlan[1-9]\d+/', $ap_iface)) {
            $skip_dhcp = true;
        } elseif ($bridgedEnable == 1 || $wifiAPEnable == 1) {
            $dhcp_cfg = join(PHP_EOL, $config);
            $status->addMessage(sprintf(_('DHCP configuration for %s enabled.'), $ap_iface), 'success');
        } elseif (!preg_match('/^interface\s'.$ap_iface.'$/m', $dhcp_cfg)) {
            $config[] = PHP_EOL;
            $config= join(PHP_EOL, $config);
            $dhcp_cfg = removeDHCPIface($dhcp_cfg,'br0');
            $dhcp_cfg = removeDHCPIface($dhcp_cfg,'uap0');
            $dhcp_cfg .= $config;
            $status->addMessage(sprintf(_('DHCP configuration for %s added.'), $ap_iface), 'success');
        } else {
            $config = join(PHP_EOL, $config);
            $dhcp_cfg = removeDHCPIface($dhcp_cfg,'br0');
            $dhcp_cfg = removeDHCPIface($dhcp_cfg,'uap0');
            $dhcp_cfg = preg_replace('/^#\sRaspAP\s'.$ap_iface.'\s.*?(?=\s*^\s*$)/ms', $config, $dhcp_cfg, 1);
            $status->addMessage(sprintf(_('DHCP configuration for %s updated.'), $ap_iface), 'success');
        }
        if (!$skip_dhcp) {
            file_put_contents("/tmp/dhcpddata", $dhcp_cfg);
            system('sudo cp /tmp/dhcpddata '.RASPI_DHCPCD_CONFIG, $return);
            if ($return == 0) {
                $status->addMessage('Wifi Hotspot settings saved', 'success');
            } else {
                $status->addMessage('Unable to save wifi hotspot settings', 'danger');
            }
        } else {
            $status->addMessage(sprintf(_('Interface %s has no default settings.'), $ap_iface), 'warning');
            $status->addMessage(('Configure settings in <strong>DHCP Server</strong> before starting AP.'), 'warning');
            $status->addMessage('Wifi Hotspot settings saved', 'success');
        }
    } else {
        $status->addMessage('Unable to save wifi hotspot settings', 'danger');
        return false;
    }
    return true;
}

/**
 * Updates a hostapd configuration
 *
 * @return boolean $result
 */
function updateHostapdConfig($ignore_broadcast_ssid,$wifiAPEnable,$bridgedEnable)
{
    // Fixed values
    $country_code = $_POST['country_code'];
    $config = 'driver=nl80211'.PHP_EOL;
    $config.= 'ctrl_interface='.RASPI_HOSTAPD_CTRL_INTERFACE.PHP_EOL;
    $config.= 'ctrl_interface_group=0'.PHP_EOL;
    $config.= 'auth_algs=1'.PHP_EOL;
    $config.= 'wpa_key_mgmt=WPA-PSK'.PHP_EOL;
    if (isset($_POST['beaconintervalEnable'])) {
        $config.= 'beacon_int='.$_POST['beacon_interval'].PHP_EOL;
    }
    if (isset($_POST['disassoc_low_ackEnable'])) {
        $config.= 'disassoc_low_ack=0'.PHP_EOL;
    }
    $config.= 'ssid='.$_POST['ssid'].PHP_EOL;
    $config.= 'channel='.$_POST['channel'].PHP_EOL;

    // Set VHT center frequency segment value
    if ((int)$_POST['channel'] < RASPI_5GHZ_CHANNEL_MIN) {
        $vht_freq_idx = 42;
    } else {
        $vht_freq_idx =  155;
    }

    if ($_POST['hw_mode'] === 'n') {
        $config.= 'hw_mode=g'.PHP_EOL;
        $config.= 'ieee80211n=1'.PHP_EOL;
        // Enable basic Quality of service
        $config.= 'wmm_enabled=1'.PHP_EOL;
    } elseif ($_POST['hw_mode'] === 'ac') {
        $config.= 'hw_mode=a'.PHP_EOL.PHP_EOL;
        $config.= '# N'.PHP_EOL;
        $config.= 'ieee80211n=1'.PHP_EOL;
        $config.= 'require_ht=1'.PHP_EOL;
        $config.= 'ht_capab=[MAX-AMSDU-3839][HT40+][SHORT-GI-20][SHORT-GI-40][DSSS_CCK-40]'.PHP_EOL.PHP_EOL;
        $config.= '# AC'.PHP_EOL;
        $config.= 'ieee80211ac=1'.PHP_EOL;
        $config.= 'require_vht=1'.PHP_EOL;
        $config.= 'ieee80211d=0'.PHP_EOL;
        $config.= 'ieee80211h=0'.PHP_EOL;
        $config.= 'vht_capab=[MAX-AMSDU-3839][SHORT-GI-80]'.PHP_EOL;
        $config.= 'vht_oper_chwidth=1'.PHP_EOL;
        $config.= 'vht_oper_centr_freq_seg0_idx='.$vht_freq_idx.PHP_EOL.PHP_EOL;
    } elseif ($_POST['hw_mode'] === 'w') {
        $config.= 'ieee80211w=2'.PHP_EOL;
        $config.= 'wpa_key_mgmt=WPA-EAP-SHA256'.PHP_EOL;
    } else {
        $config.= 'hw_mode='.$_POST['hw_mode'].PHP_EOL;
        $config.= 'ieee80211n=0'.PHP_EOL;
    }
    if ($_POST['wpa'] !== 'none') {
        $config.= 'wpa_passphrase='.$_POST['wpa_passphrase'].PHP_EOL;
    }
    if ($wifiAPEnable == 1) {
        $config.= 'interface=uap0'.PHP_EOL;
    } elseif ($bridgedEnable == 1) {
        $config.='interface='.$_POST['interface'].PHP_EOL;
        $config.= 'bridge=br0'.PHP_EOL;
    } else {
        $config.= 'interface='.$_SESSION['ap_interface'].PHP_EOL;
    }
    $config.= 'wpa='.$_POST['wpa'].PHP_EOL;
    $config.= 'wpa_pairwise='.$_POST['wpa_pairwise'].PHP_EOL;
    $config.= 'country_code='.$_POST['country_code'].PHP_EOL;
    $config.= 'ignore_broadcast_ssid='.$ignore_broadcast_ssid.PHP_EOL;
    if (isset($_POST['max_num_sta'])) {
        $config.= 'max_num_sta='.$_POST['max_num_sta'].PHP_EOL;
    }

    $config.= parseUserHostapdCfg();

    file_put_contents("/tmp/hostapddata", $config);
    system("sudo cp /tmp/hostapddata " . RASPI_HOSTAPD_CONFIG, $result);
    return $result;
}

/**
 * Executes iw to set the specified ISO 2-letter country code
 *
 * @param string $country_code
 * @param object $status
 * @return boolean $result
 */
function iwRegSet(string $country_code, $status)
{
    $country_code = escapeshellarg($country_code);
    $result = shell_exec("sudo iw reg set $country_code");
    $status->addMessage(sprintf(_('Setting wireless regulatory domain to %s'), $country_code, 'success'));
    return $result;
}

/**
 * Parses optional /etc/hostapd/hostapd.conf.users file
 *
 * @return string $tmp
 */
function parseUserHostapdCfg()
{
    if (file_exists(RASPI_HOSTAPD_CONFIG . '.users')) {
        exec('cat '. RASPI_HOSTAPD_CONFIG . '.users', $hostapdconfigusers);
        foreach ($hostapdconfigusers as $hostapdconfigusersline) {
            if (strlen($hostapdconfigusersline) === 0) {
                continue;
            }
            if ($hostapdconfigusersline[0] != "#") {
                $arrLine = explode("=", $hostapdconfigusersline);
                $tmp.= $arrLine[0]."=".$arrLine[1].PHP_EOL;;
            }
        }
        return $tmp;
    }
}