servnest/fn/dns.php

<?php

function knotcExec($suffix, $cmd) {
	$action = checkAction($_POST['action']);

	exec(CONF['dns']['knotc_path'] . " zone-begin " . $suffix, $output['begin'], $code['begin']);
	if ($code['begin'] !== 0)
		serverError("<code>knotc</code> failed with exit code <samp>" . $code['begin'] . "</samp>: <samp>" . $output['begin'][0] . "</samp>.");

	exec(CONF['dns']['knotc_path'] . " zone-" . $action . "set " . $suffix . " " . implode(" ", $cmd), $output['op'], $code['op']);
	if ($code['op'] !== 0) {
		exec(CONF['dns']['knotc_path'] . " zone-abort " . $suffix);
		serverError("<code>knotc</code> failed with exit code <samp>" . $code['op'] . "</samp>: <samp>" . $output['op'][0] . "</samp>.");
	}

	exec(CONF['dns']['knotc_path'] . " zone-commit " . $suffix, $output['commit'], $code['commit']);
	if ($code['commit'] !== 0) {
		exec(CONF['dns']['knotc_path'] . " zone-abort " . $suffix);
		serverError("<code>knotc</code> failed with exit code <samp>" . $code['commit'] . "</samp>: <samp>" . $output['commit'][0] . "</samp>.");
	}
}

function checkIpFormat($ip) {
	if (!filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_NO_PRIV_RANGE))
		userError("IP address is on the private range.");
	if (!filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_NO_RES_RANGE))
		userError("IP address is on the reserved range.");
	if (filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_IPV4))
		return "A";
	if (filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_IPV6))
		return "AAAA";
	userError("IP address malformed.");
}

function checkAbsoluteDomainFormat($domain) {
	// If the domain must end with a dot
	if (!filter_var($domain, FILTER_VALIDATE_DOMAIN) OR !preg_match("/^([a-z0-9_-]{1,63}\.){2,127}$/", $domain))
		userError("Domain malformed.");
}

function checkAction($action) {
	return match ($action) {
		'add' => '',
		'delete' => 'un',
		default => userError("Wrong value for action."),
	};
}