<?php

/*  Poweradmin, a friendly web-based admin tool for PowerDNS.

 *  See <https://rejo.zenger.nl/poweradmin> for more details.

 *

 *  Copyright 2007, 2008  Rejo Zenger <rejo@zenger.nl>

 *

 *  This program is free software: you can redistribute it and/or modify

 *  it under the terms of the GNU General Public License as published by

 *  the Free Software Foundation, either version 3 of the License, or

 *  (at your option) any later version.

 *

 *  This program is distributed in the hope that it will be useful,

 *  but WITHOUT ANY WARRANTY; without even the implied warranty of

 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 *  GNU General Public License for more details.

 *

 *  You should have received a copy of the GNU General Public License

 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.

 */

function validate_input($zid, $type, &$content, &$name, &$prio, &$ttl) {

	$zone = get_zone_name_from_id($zid);				// TODO check for return

	if (!(preg_match("/$zone$/i", $name))) {

		if (isset($name) && $name != "") {

			$name = $name . "." . $zone;

		} else {

			$name = $zone;

		}

	}

	switch ($type) {

		case "A":

			if (!is_valid_ipv4($content)) return false;

			break;

		case "AAAA":

			if (!is_valid_ipv6($content)) return false;

			break;

		case "CNAME":

			if (!is_valid_rr_cname_name($name)) return false;

			if (!is_valid_hostname_fqdn($content,0)) return false;

			break;

		case "HINFO":

			if (!is_valid_rr_hinfo_content($content)) return false;

			break;

		case "MX":

			if (!is_valid_hostname_fqdn($content,0)) return false;

			break;

		case "NS":

			if (!is_valid_hostname_fqdn($content,0)) return false;

			break;

		case "PTR":

			if (!is_valid_hostname_fqdn($content,0)) return false;

			break;

		case "SOA":

			if (!is_valid_rr_soa_name($name,$zone)) return false;

			if (!is_valid_rr_soa_content($content)) return false;

			break;

		case "TXT":

			break;

		case "MBOXFW":

		case "NAPTR":

		case "URL":

			// These types are supported by PowerDNS, but there is not

			// yet code for validation. Validation needs to be added 

			// for these types. One Day Real Soon Now. [tm]

			break;

		default:

			error(ERR_DNS_RR_TYPE);

			return false;

	}

	if (!is_valid_rr_prio($prio,$type)) return false;

	if (!is_valid_rr_ttl($ttl)) return false;

	return true;

}

function is_valid_hostname_fqdn($hostname, $wildcard) {

	global $dns_strict_tld_check;

	global $valid_tlds;

	$hostname = ereg_replace("\.$","",$hostname);

	if (strlen($hostname) > 255) {

		error(ERR_DNS_HN_TOO_LONG);

		return false;

	}

        $hostname_labels = explode ('.', $hostname);

        $label_count = count($hostname_labels);

	foreach ($hostname_labels as $hostname_label) {

		if ($wildcard == 1 && !isset($first)) {

			if (!preg_match('/^(\*|[\w-\/]+)$/',$hostname_label)) { error(ERR_DNS_HN_INV_CHARS); return false; }

			$first = 1;

		} else {

			if (!preg_match('/^[\w-\/]+$/',$hostname_label)) { error(ERR_DNS_HN_INV_CHARS); return false; }

		}

		if (substr($hostname_label, 0, 1) == "-") { error(ERR_DNS_HN_DASH); return false; }

		if (substr($hostname_label, -1, 1) == "-") { error(ERR_DNS_HN_DASH); return false; }

		if (strlen($hostname_label) < 1 || strlen($hostname_label) > 63) { error(ERR_DNS_HN_LENGTH); return false; }

	}

	if ($hostname_labels[$label_count-1] == "arpa" && (substr_count($hostname_labels[0], "/") == 1 XOR substr_count($hostname_labels[1], "/") == 1)) {

		if (substr_count($hostname_labels[0], "/") == 1) { 

			$array = explode ("/", $hostname_labels[0]);

		} else {

			$array = explode ("/", $hostname_labels[1]);

		}

		if (count($array) != 2) { error(ERR_DNS_HOSTNAME) ; return false; }

		if (!is_numeric($array[0]) || $array[0] < 0 || $array[0] > 255) { error(ERR_DNS_HOSTNAME) ; return false; }

		if (!is_numeric($array[1]) || $array[1] < 25 || $array[1] > 31) { error(ERR_DNS_HOSTNAME) ; return false; }

	} else {

		if (substr_count($hostname, "/") > 0) { error(ERR_DNS_HN_SLASH) ; return false; }

	}

	if ($dns_strict_tld_check == "1" && !in_array($hostname_labels[$label_count-1], $valid_tlds)) {

		error(ERR_DNS_INV_TLD); return false;

	}

	return true;

}

function is_valid_ipv4($ipv4) {

// 20080424/RZ: The current code may be replaced by the following if() 

// statement, but it will raise the required PHP version to ">= 5.2.0". 

// Not sure if we want that now.

//

//	if(filter_var($ipv4, FILTER_VALIDATE_IP, FILTER_FLAG_IPV4) === FALSE) {

//		error(ERR_DNS_IPV4); return false;

//	}

	if (!preg_match("/^[0-9\.]{7,15}$/", $ipv4)) {

		error(ERR_DNS_IPV4); return false;

	}

	$quads = explode('.', $ipv4);

	$numquads = count($quads);

	if ($numquads != 4) {

		error(ERR_DNS_IPV4); return false;

	}

	for ($i = 0; $i < 4; $i++) {

		if ($quads[$i] > 255) {

			error(ERR_DNS_IPV4); return false;

		}

	}

	return true;

}

function is_valid_ipv6($ipv6) {

// 20080424/RZ: The current code may be replaced by the following if() 

// statement, but it will raise the required PHP version to ">= 5.2.0". 

// Not sure if we want that now.

//

//	if(filter_var($ipv6, FILTER_VALIDATE_IP, FILTER_FLAG_IPV6) === FALSE) {

//		error(ERR_DNS_IPV6); return false;

//	}

	if (!preg_match("/^[0-9a-f]{0,4}:([0-9a-f]{0,4}:){0,6}[0-9a-f]{0,4}$/i", $ipv6)) {

		error(ERR_DNS_IPV6); return false;

	}

	$quads = explode(':', $ipv6);

	$numquads = count ($quads);

	if ($numquads > 8 || $numquads < 3) {

		error(ERR_DNS_IPV6); return false;

	}

	$emptyquads = 0;

	for ($i = 1; $i < $numquads-1; $i++) {

		if ($quads[$i] == "") $emptyquads++;

	}

	if ($emptyquads > 1) {

		error(ERR_DNS_IPV6); return false;

	}

	if ($emptyquads == 0 && $numquads != 8) {

		error(ERR_DNS_IPV6); return false;

	}

	return true;

}

function is_valid_rr_cname_name($name) {

	global $db;

	$query = "SELECT type, content 

			FROM records 

			WHERE content = " . $db->quote($name) . "

			AND (type = 'MX' OR type = 'NS')";

	$response = $db->query($query);

	if (PEAR::isError($response)) { error($response->getMessage()); return false; };

	if ($response->numRows() > 0) {

		error(ERR_DNS_CNAME); return false;

	}

	return true;

}

	global $db;

	$query = "SELECT type, name

			FROM records

			AND TYPE = 'CNAME'";

	$response = $db->query($query);

	if (PEAR::isError($response)) { error($response->getMessage()); return false; };

	if ($response->numRows() > 0) {

		error(ERR_DNS_MX_NS_TO_CNAME); return false;

	}

	return true;

}

function is_valid_rr_hinfo_content($content) {

	if ($content[0] == "\"") {

		$fields = preg_split('/(?<=") /', $content, 2);

	} else {

		$fields = preg_split('/ /', $content, 2);

	}

	for ($i = 0; ($i < 2); $i++) {

		if (!preg_match("/^([^\s]{1,1000}|\"([^\"]{1,998}\")$/i", $fields[$i])) {

			error(ERR_DNS_HINFO_INV_CONTENT); return false;

		}

	}

	return true;

}

function is_valid_rr_soa_content(&$content) {

	$fields = preg_split("/\s+/", trim($content));

        $field_count = count($fields);

	if ($field_count == 0 || $field_count > 7) {

		return false;

	} else {

		if (!is_valid_hostname_fqdn($fields[0]) || preg_match('/\.arpa\.?$/',$fields[0])) {

			return false;

		}

		$final_soa = $fields[0];

		if (isset($fields[1])) {

			$addr_input = $fields[1];

		} else {

			global $dns_hostmaster;

			$addr_input = $dns_hostmaster;

		}

		if (!preg_match("/@/", $addr_input)) {

			$addr_input = preg_split('/(?<!\\\)\./', $addr_input, 2);

			$addr_to_check = str_replace("\\", "", $addr_input[0]) . "@" . $addr_input[1];

		} else {

			$addr_to_check = $addr_input;

		}

		if (!is_valid_email($addr_to_check)) {

			return false;

		} else {

			$addr_final = explode('@', $addr_to_check, 2);

			$final_soa .= " " . str_replace(".", "\\.", $addr_final[0]) . "." . $addr_final[1];

		}

		if (isset($fields[2])) {

			if (!is_numeric($fields[2])) {

				return false;

			}

			$final_soa .= " " . $fields[2];

		} else {

			$final_soa .= " 0";

		}

		if ($field_count == 7) {

			for ($i = 3; ($i < 7); $i++) {

				if (!is_numeric($fields[$i])) {

					return false;

				} else {

					$final_soa .= " " . $fields[$i];

				}

			}

		}

	}

	$content = $final_soa;

	return true;

}

function is_valid_rr_soa_name($name, $zone) {

	if ($name != $zone) {

		error(ERR_DNS_SOA_NAME); return false;

	}

	return true;

}

function is_valid_rr_prio(&$prio, $type) {

		if (!is_numeric($prio) || $prio < 0 || $prio > 65535 ) {

			error(ERR_DNS_INV_PRIO); return false;

		}

	} else {

		$prio = "";

	}

	return true;

}