functions.php

<?php

/* Wrapper for curl */
function requestCurl($data) {
	$ch = curl_init(HOST);
	curl_setopt($ch, CURLOPT_POSTFIELDS, $data);
	curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
	curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);

	if (!$data = curl_exec($ch)) {
		trigger_error('Curl execution error.' . curl_error($ch), E_USER_ERROR);
		return false;
	}

	curl_close($ch);
	return $data;
}

function validIP($ip) {
	if (filter_var($ip, FILTER_VALIDATE_IP)) {
		return true;
	}
	return false;
}

function validIPv6($ip) {
	if (filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_IPV6)) {
		return true;
	}
	return false;
}

function validDomain($domain) {
	return (preg_match("/^([a-z\d](-*[a-z\d])*)(\.([a-z\d](-*[a-z\d])*))*$/i", $domain) //valid chars check
	  && preg_match('/^.{1,253}$/', $domain) //overall length check
	  && preg_match("/^[^\.]{1,63}(\.[^\.]{1,63})*$/", $domain)); //length of each label
}

function configuredDomain($domain) {
	if (defined('DOMAINS')) {
		$domains = unserialize(DOMAINS);
		return array_key_exists($domain, $domains);
	} else {
		return $domain == DOMAIN;
	}
}

function validCred($pass) {
	if ($pass == REMOTE_PASS) {
		return true;
	}
	return false;
}

/* Respond with status & message in JSON */
function respond($status, $msg = '') {
	header('Content-type: application/json');
	$response = array();
	$response['status'] = $status;
	if (!empty($msg)) {
		$response['msg'] = $msg;
	}
	$out = json_encode($response);
	if ($status != 'success') {
		$response['msg'] .= PHP_EOL . 'See ' . LOG . ' for additional information.';
		file_put_contents('php://stderr', $out);
		exit(1);
	} else {
		echo $out;
		exit();
	}
}

/* Custom error handler to log to file */
function dyndns_error_handler($errno, $errstr, $errfile, $errline) {
	if (!(error_reporting() & $errno)) {
		// This error code is not included in error_reporting
		return;
	}

	$date = date(DATE_W3C);
	$str = '';

	switch ($errno) {
		case E_USER_ERROR:
			$str .= "$date ERROR [$errno]: $errstr, Fatal error on line $errline in file $errfile";
			break;

		case E_USER_WARNING:
			$str .= "$date WARNING [$errno]: $errstr\n";
			break;

		case E_USER_NOTICE:
			$str .= "$date NOTICE [$errno]: $errstr\n";
			break;

		default:
			$str .= "$date Unknown error type: [$errno] $errstr\n";
			break;
	}

	file_put_contents(LOG, $str, FILE_APPEND);

	/* Don't execute PHP internal error handler */
	return true;
}