udp_server.php

<?php

// default values

$conf ['version'] = "v0.1"; // verze
$conf ['bind_address'] = '0.0.0.0';
$conf ['bind_port'] = 9999;
$conf ['base_dir'] = dirname ( __FILE__ );
$conf ['log_filename'] = $conf ['base_dir'] . "/log/nbiot_udp.log";

$conf ['api_url'] = 'http://example.com/api/ttn_update';
$conf ['api_app_id'] = 'SensoricNet';
$conf ['api_validate_ssl_cert'] = false;

$conf['dbhost'] = "127.0.0.1";
$conf['dbname'] = "sensoricnet";
$conf['dbuser'] = "sensoricnet";
$conf['dbpasswd'] = "";
$conf['dbreconnection'] = 10;

// when defined, use basic auth
//$conf['api_auth_user'] = 'username';
//$conf['api_auth_pass'] = 'password';

$conf ['log_severities'] = array (
		'emergency' => 0,
		'alert' => 1,
		'critical' => 2,
		'error' => 3,
		'warning' => 4,
		'notice' => 5,
		'info' => 6,
		'debug' => 7 
);
$conf ['log_severity'] = 'debug';

if (file_exists($conf ['base_dir'] . "/config.php")) {
	include_once $conf ['base_dir'] . "/config.php";
}


/************************************************
 * constants
 ************************************************/

// #define LPP_DIGITAL_INPUT 0 // 1 byte
$lpp_definition [0] ['name'] = 'digital_in';
$lpp_definition [0] ['size'] = 1;
// #define LPP_DIGITAL_OUTPUT 1 // 1 byte
$lpp_definition [1] ['name'] = 'digital_out';
$lpp_definition [1] ['size'] = 1;
// #define LPP_ANALOG_INPUT 2 // 2 bytes, 0.01 signed
$lpp_definition [2] ['name'] = 'analog_in';
$lpp_definition [2] ['size'] = 2;
// #define LPP_ANALOG_OUTPUT 3 // 2 bytes, 0.01 signed
$lpp_definition [3] ['name'] = 'analog_out';
$lpp_definition [3] ['size'] = 2;
// #define LPP_LUMINOSITY 101 // 2 bytes, 1 lux unsigned
$lpp_definition [101] ['name'] = 'luminosity';
$lpp_definition [101] ['size'] = 2;
// #define LPP_PRESENCE 102 // 1 byte, 1
$lpp_definition [102] ['name'] = 'presence';
$lpp_definition [102] ['size'] = 1;
// #define LPP_TEMPERATURE 103 // 2 bytes, 0.1°C signed
$lpp_definition [103] ['name'] = 'temperature';
$lpp_definition [103] ['size'] = 2;
// #define LPP_RELATIVE_HUMIDITY 104 // 1 byte, 0.5% unsigned
$lpp_definition [104] ['name'] = 'relative_humidity';
$lpp_definition [104] ['size'] = 1;
// #define LPP_ACCELEROMETER 113 // 2 bytes per axis, 0.001G
$lpp_definition [113] ['name'] = 'accelerometer';
$lpp_definition [113] ['size'] = 2;
// #define LPP_BAROMETRIC_PRESSURE 115 // 2 bytes 0.1 hPa Unsigned
$lpp_definition [115] ['name'] = 'barometric_pressure';
$lpp_definition [115] ['size'] = 2;
// #define LPP_GYROMETER 134 // 2 bytes per axis, 0.01 °/s
$lpp_definition [134] ['name'] = 'gyrometer';
$lpp_definition [134] ['size'] = 6;
// #define LPP_GPS 136 // 3 byte lon/lat 0.0001 °, 3 bytes alt 0.01 meter
$lpp_definition [136] ['name'] = 'gps';
$lpp_definition [136] ['size'] = 9;

/**
 * logovani podle nastavene severity na obrazovku a do souboru
 *
 * @param string $severity
 * @param string $text
 */
function logit($severity, $text) {
	global $conf, $log;
	
	if ($conf ['log_severities'] [$conf ['log_severity']] >= $conf ['log_severities'] [$severity]) {
		$text_array = explode ( "\n", $text );
		foreach ( $text_array as $line ) {
			fputs ( $log, date ( "Ymd H:i:s " ) . strtoupper ( $severity ) . ": " . $line . "\n" );
		}
	}
}

/**
 * Dekoduje nas nbiot udp packet s cayenne lpp daty do objektu
 *
 * @param string $data
 */
function udp_packet_decode($data) {
	global $lpp_definition, $dev_id;
	
	$byte_array = unpack ( 'C*', $data );
	
	$output_object = new stdClass ();
	
	// struktura udp packetu je tato:
	// [dev_id]/0[lpp_data]
	
	// precti dev_id
	$dev_id='';
	do {
		$char = array_shift ( $byte_array );
		$dev_id .= chr($char);
	} while ( $char != 0 );
	$dev_id = trim ( $dev_id );
	
	// dekoduj lpp
	while ( count ( $byte_array ) > 0 ) {
		$sensor_number = array_shift ( $byte_array );
		$field_code = array_shift ( $byte_array );
		
		// existuje tento lpp key?
		if (array_key_exists ( $field_code, $lpp_definition )) {
			$field_name = $lpp_definition [$field_code] ['name'];
			$field_size = $lpp_definition [$field_code] ['size'];
			
			switch ($field_code) {
				case 0 :
				case 1 :
				case 102 :
					$field_value = array_shift ( $byte_array );
					$output_object->{$field_name . "_" . $sensor_number} = $field_value;
					break;
				case 2 :
				case 3 :
					$field_value = (256 * array_shift ( $byte_array ) + array_shift ( $byte_array )) / 100;
					$output_object->{$field_name . "_" . $sensor_number} = $field_value;
					break;
				case 103 :
				case 115 :
					$field_value = (256 * array_shift ( $byte_array ) + array_shift ( $byte_array ));
					if ($field_value >= 32768) $field_value = $field_value - 65536;
					$field_value = $field_value / 10;
					$output_object->{$field_name . "_" . $sensor_number} = $field_value;
					break;
				case 101 :
					$field_value = 256 * array_shift ( $byte_array ) + array_shift ( $byte_array );
					$output_object->{$field_name . "_" . $sensor_number} = $field_value;
					break;
				case 104 :
					$field_value = array_shift ( $byte_array ) / 2;
					$output_object->{$field_name . "_" . $sensor_number} = $field_value;
					break;
				case 113 :
					$accelerometer_object = new stdClass ();
					// correct object names TODO
					$accelerometer_object->vx = (256 * array_shift ( $byte_array ) + array_shift ( $byte_array )) / 1000;
					$accelerometer_object->vy = (256 * array_shift ( $byte_array ) + array_shift ( $byte_array )) / 1000;
					$accelerometer_object->vz = (256 * array_shift ( $byte_array ) + array_shift ( $byte_array )) / 1000;
					$output_object->{$field_name . "_" . $sensor_number} = $accelerometer_object;
					break;
				case 134 :
					$gyrometer_object = new stdClass ();
					$gyrometer_object->vx = (256 * array_shift ( $byte_array ) + array_shift ( $byte_array )) / 100;
					$gyrometer_object->vy = (256 * array_shift ( $byte_array ) + array_shift ( $byte_array )) / 100;
					$gyrometer_object->vz = (256 * array_shift ( $byte_array ) + array_shift ( $byte_array )) / 100;
					$output_object->{$field_name . "_" . $sensor_number} = $gyrometer_object;
					break;
				case 136 :
					$gps_object = new stdClass ();
					$gps_object->latitude = (65536 * array_shift ( $byte_array ) + 256 * array_shift ( $byte_array ) + array_shift ( $byte_array )) / 10000;
					$gps_object->longitude = (65536 * array_shift ( $byte_array ) + 256 * array_shift ( $byte_array ) + array_shift ( $byte_array )) / 10000;
					$gps_object->altitude = (65536 * array_shift ( $byte_array ) + 256 * array_shift ( $byte_array ) + array_shift ( $byte_array )) / 100;
					$output_object->{$field_name . "_" . $sensor_number} = $gps_object;
					break;
				default :
				// invalid lpp, TODO
			}
		} else {
			logit ( 'warning', "lpp key $field_code does not exist" );
			// co ted? prohledavat dal, nebo failnout?
		}
	}
	
	// logit('debug', print_r($output_object, true));
	return $output_object;
}



/**
 * s periodou nastavenou v konfiguraci testuje pripojeni k db, pripadne se pokusi o rekonekci
 * 
 * @throws PDOException
 * @return boolean
 */
function test_db_connection() {
	global $conf, $db, $last_time;
	
	$time_now = time();
	$last_test = $time_now - $last_time;
	
	if (($time_now - $last_time) > $conf['dbreconnection']) {
		$last_time = time();
		
		if ($db instanceof \PDO) {
			try {
				$query = $db->query ('SELECT 1');
				logit ('debug', print_r($query, true));
				if ($query) {
					$query->execute ();
					logit ("info", "Db connection is alive.");
					return true;
				} else throw new PDOException("cannot execute query");
			} catch(PDOException $e) {
				logit ("warning", "Db connection is broken. ".$e->getMessage());
				$db = null;
			}
		} else {
			// reconnect to db
			try {
				logit ("info", "Trying to reconnected to db...");
				$db = new PDO("mysql:host=".$conf['dbhost'].";dbname=".$conf['dbname'].";charset=utf8", $conf['dbuser'], $conf['dbpasswd']);
				$db->exec("set names utf8");
				logit ("info", "Reconnected to db.");
				return true;
			} catch (PDOException $e) {
				logit ("error", "Db reconnection error. ".$e->getMessage());
			}
		}
	} else {
		logit ("debug", "Not testing db connection because its just ".$last_test."s from last test.");
		if ($db instanceof \PDO) return true;
	}
	return false;
}


/************************************************************
 * main
 * **********************************************************/

// Reduce errors
error_reporting ( E_ALL & ~E_NOTICE & ~E_STRICT & ~E_DEPRECATED);

// logovaci soubor
$log = fopen ( $conf ['log_filename'], "a" );
if (! $log) {
	die ( "Cannot open log file " . $conf ['log_filename'] );
}

logit ( 'info', "SensoricNet UDP reciever version " . $conf ['version'] );

$last_time = time();

// connect to db
try {
	$db = new PDO("mysql:host=".$conf['dbhost'].";dbname=".$conf['dbname'].";charset=utf8", $conf['dbuser'], $conf['dbpasswd']);
	$db->exec("set names utf8");
	logit ("info", "pripojeni k db je ok");
} catch (PDOException $e) {
	logit ("error", "Chyba pri pripojeni k databazi. ".$e->getMessage());
}


// Create a UDP socket
if (! ($sock = socket_create ( AF_INET, SOCK_DGRAM, 0 ))) {
	$errorcode = socket_last_error ();
	$errormsg = socket_strerror ( $errorcode );
	
	logit ( 'emergency', "Couldn't create socket: [$errorcode] $errormsg" );
	die ("Couldn't create socket: [$errorcode] $errormsg"."\n");
}

// Bind the source address
if (! socket_bind ( $sock, $conf ['bind_address'], $conf ['bind_port'] )) {
	$errorcode = socket_last_error ();
	$errormsg = socket_strerror ( $errorcode );
	
	logit ( 'emergency', "Couldn't bind socket: [$errorcode] $errormsg" );
	die ("Couldn't bind socket: [$errorcode] $errormsg"."\n");
}

logit ( 'info', "Listening on " . $conf ['bind_address'] . ":" . $conf ['bind_port'] );

// Do some communication, this loop can handle multiple clients
while ( 1 ) {
	
	// Receive some data
	$r = socket_recvfrom ( $sock, $buf, 512, 0, $remote_ip, $remote_port );
	logit ( 'info', "UDP packet recieved. Remote IP: ".$remote_ip.", remote port: ".$remote_port.", payload length: ".strlen($buf) );
	logit ( 'debug', "UDP packet data dump: " . print_r ( unpack ( 'H*', $buf ), true ) );
	
	$date = new DateTime ();
	
	// do the magic here...
	
	// test validity of packet TODO
	
	// decode udp data packet
	$payload_fields = udp_packet_decode ( $buf );
	
	// create ttn json structure and call SensoricNet api
	$gateway_object = new stdClass ();
	$gateway_object->gtw_id = 'Vodafone_NBIot';
	$gateway_object->timestamp = $date->format ( 'U' );
	$gateway_object->time = $date->format ( 'Y-m-d\TH:i:s.vP' ); // '2018-03-08T22:20:35.944604Z'; TODO
	$gateway_object->channel = '0'; // TODO
	$gateway_object->rssi = '0'; // TODO
	$gateway_object->snr = '0'; // TODO
	$gateway_object->rf_chain = '0'; // TODO
	$gateway_object->latitude = '0'; // TODO
	$gateway_object->longitude = '0'; // TODO
	$gateway_object->altitude = '0'; // TODO
	
	$metadata_object = new stdClass ();
	$metadata_object->time = $date->format ( 'Y-m-d\TH:i:s.vP' ); // TODO
	$metadata_object->frequency = '900'; // TODO
	$metadata_object->modulation = 'NBIoT';
	$metadata_object->data_rate = ''; // TODO
	$metadata_object->coding_rate = ''; // TODO
	$metadata_object->gateways = array (
			0 => $gateway_object 
	);
	
	$ttn_object = new stdClass ();
	$ttn_object->app_id = $conf ['api_app_id'];
	$ttn_object->dev_id = $dev_id;
	$ttn_object->hardware_serial = '0000000000000000'; // TODO
	$ttn_object->port = '1'; // TODO
	$ttn_object->counter = '0'; // TODO
	$ttn_object->payload_raw = base64_encode($buf);
	$ttn_object->payload_fields = $payload_fields;
	$ttn_object->metadata = $metadata_object;
	$ttn_object->downlink_url = ''; // TODO
	
	logit ( 'debug', print_r ( $ttn_object, true ) );
	
	// profit
	$ch = curl_init ( $conf ['api_url'] );
	
	curl_setopt ( $ch, CURLOPT_POST, 1 );
	curl_setopt ( $ch, CURLOPT_POSTFIELDS, json_encode ( $ttn_object ) );
	curl_setopt ( $ch, CURLOPT_RETURNTRANSFER, 1 );
	if ($conf['api_validate_ssl_cert'] === false) curl_setopt ( $ch, CURLOPT_SSL_VERIFYPEER, false );
	curl_setopt ( $ch, CURLOPT_HTTPHEADER, array (
			'Content-Type: application/json' 
	) );
	if ($conf['api_auth_user'] and $conf['api_auth_pass']) curl_setopt ( $ch, CURLOPT_USERPWD, $conf['api_auth_user'] . ":" . $conf['api_auth_pass'] );
//	curl_setopt($ch, CURLOPT_TIMEOUT, 30);
	
	$result = curl_exec ( $ch );
	if ($result === false) {
		logit ( 'error', "Curl call failed. Error was " . curl_error ( $ch ) );
	} else {
		$http_code = curl_getinfo ( $ch, CURLINFO_HTTP_CODE );
		if ($http_code != '200') {
			logit ( 'warning', "Curl call was successful but return code is $http_code" );
		} else {
			logit ( 'info', "Curl call was successful, return code is $http_code" );
		}
	}
	curl_close ( $ch );
	
	// zkontroluj jestli neni pro toto devId naplanovany nejaky downstream packet
	
	if (test_db_connection()) {
	
		try {
			logit ('debug', "making sql query");
			$query = $db->prepare ('
				SELECT id, packet FROM `downstream`
				WHERE sensorDevId = :dev_id LIMIT 1
			');
			$query->bindParam ( ':dev_id', $dev_id);
			$query->execute ();
			$result = $query->fetch ( PDO::FETCH_ASSOC );
		} catch (PDOException $e) {
			logit ("error", "Chyba pri pripojeni k databazi. ".$e->getMessage());
			$result = false;
		}
		
		if ($result) {
			// mame downstream packet, je treba ho poslat...
			$downstream_id = $result['id'];
			$packet = $result['packet'];
	
			logit ( 'debug', "downstream packet data dump: " . print_r ( unpack ( 'H*', $packet ), true ) );
			
			// posilame na ip addr a port, ze ktereho udp packet prisel
			$retval = socket_sendto($sock, $packet, strlen($packet), 0, $remote_ip, $remote_port);
			if ($retval === false) {
				logit ( 'error', "Cannot send udp downstream message id $downstream_id for devId $dev_id" );
			} else {
				logit ( 'info', "Successfully sent udp downstream message id $downstream_id for devId $dev_id" );
	
				try {
					// smazeme tento downstream z tabulky
					$query = $db->prepare ('
						DELETE FROM `downstream`
						WHERE id = :downstream_id
					');
					$query->bindParam ( ':downstream_id', $downstream_id);
					$result = $query->execute ();
				} catch (PDOException $e) {
					logit ("error", "Chyba pri pripojeni k databazi. ".$e->getMessage());
					$result = false;
				}
				
				if ($result == 1) {
					logit ( 'info', "Successfully deleted downstream message id $downstream_id for devId $dev_id from db" );
				} else {
					logit ( 'error', "Failed to delete downstream message id $downstream_id for devId $dev_id from db" );
				}
				
			}
		}
	} else {
		logit ('warning', "not connected to db...");
	}
}