<?php

/*
Copyright (c) 2007, Till Brehm, projektfarm Gmbh
All rights reserved.

Redistribution and use in source and binary forms, with or without modification,
are permitted provided that the following conditions are met:

    * Redistributions of source code must retain the above copyright notice,
      this list of conditions and the following disclaimer.
    * Redistributions in binary form must reproduce the above copyright notice,
      this list of conditions and the following disclaimer in the documentation
      and/or other materials provided with the distribution.
    * Neither the name of ISPConfig nor the names of its contributors
      may be used to endorse or promote products derived from this software without
      specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

/*
    DNS validation
*/

class validate_dns {

	function validate_field($field, $area, $zoneid, $wildcard_allowed = 1){
		//$desc: Name, Data, RP mbox, RP txtref, SRV target, Zone origin, Name server, Admin email
		global $app, $conf;

		switch ($area) {
		case "Name":
			$desc = $app->tform->wordbook['name_txt'];
			break;
		case "Data":
			$desc = $app->tform->wordbook['data_txt'];
			break;
		case "RP mbox":
			$desc = $app->tform->wordbook['rp_mbox_txt'];
			break;
		case "RP txtref":
			$desc = $app->tform->wordbook['rp_txtref_txt'];
			break;
		case "SRV target":
			$desc = $app->tform->wordbook['srv_target_txt'];
			break;
		case "Zone origin":
			$desc = $app->tform->wordbook['zone_origin_txt'];
			break;
		case "Name server":
			$desc = $app->tform->wordbook['ns_txt'];
			break;
		case "Admin email":
			$desc = $app->tform->wordbook['mbox_txt'];
			break;
		}

		$error = '';

		$valid_characters = "*ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz1234567890-_";

		if(strlen($field) > 255) $error .= $desc." ".$app->tform->wordbook['error_255_characters']."<br>\r\n";

		$parts = explode(".", $field);
		$i = 0;
		$empty = 0;
		foreach ($parts as $part){
			$i++;

			if(trim($part) == '') $empty += 1;

			if(strlen($part) > 63) $error .= $desc." ".$app->tform->wordbook['error_63_characters']."<br>\r\n";

			if(strspn($part, $valid_characters) != strlen($part)) $error .= $desc." ".$app->tform->wordbook['error_invalid_characters']."<br>\r\n";

			if(substr($part, 0, 1) == '-') $error .= $desc." ".$app->tform->wordbook['error_hyphen_begin']."<br>\r\n";
			if(substr($part, -1) == '-') $error .= $desc." ".$app->tform->wordbook['error_hyphen_end']."<br>\r\n";

			if(strstr($part, "*")){
				if($wildcard_allowed){
					if($i != 1) $error .= $desc." ".$app->tform->wordbook['error_wildcard_non_initial_part']."<br>\r\n";

					if($part != "*") $error .= $desc." ".$app->tform->wordbook['error_wildcard_mix']."<br>\r\n";
				} else {
					$error .= $desc." ".$app->tform->wordbook['error_no_wildcard_allowed']."<br>\r\n";
				}
			}
		}

		if(substr($field, -1) == '.'){
			if($i > 2 && $empty > 1) $error .= $desc." ".$app->tform->wordbook['error_invalid_characters']."<br>\r\n";
		} else {
			if($empty > 0 && $field != '') $error .= $desc." ".$app->tform->wordbook['error_invalid_characters']."<br>\r\n";
		}

		if(substr($field, -1) == '.' && $area == 'Name'){
			$soa = $app->db->queryOneRecord("SELECT * FROM soa WHERE id = ?", $zoneid);
			if(substr($field, (strlen($field) - strlen($soa['origin']))) != $soa['origin']) $error .= $desc." ".$app->tform->wordbook['error_out_of_zone']."<br>\r\n";
		}

		return $error;
	}

	function validate_rp_data(&$data, $zoneid){
		global $app, $conf;
		$error = '';
		$fields = explode(" ", trim($data));
		if(count($fields) != 2) return $error .= $app->tform->wordbook['data_txt']." ".$app->tform->wordbook['error_invalid_rp']."<br>\r\n";
		$mbox = $fields[0];
		$txtref = $fields[1];

		$error .= $this->validate_field($mbox, 'RP mbox', $zoneid, 0);
		$error .= $this->validate_field($txtref, 'RP txtref', $zoneid, 0);

		$data = $mbox." ".$txtref;
		return $error;
	}

	function validate_srv_data(&$data, $zoneid){
		global $app, $conf;
		$error = '';

		$fields = explode(" ", trim($data));
		if(count($fields) != 3) return $error .= $app->tform->wordbook['data_txt']." ".$app->tform->wordbook['error_invalid_srv']."<br>\r\n";

		$weight = $fields[0];
		$port = $fields[1];
		$target = $fields[2];
		if($weight < 0 || $weight > 65535) $error .= $app->tform->wordbook['weight_txt']." (\"<i>" . htmlentities($weight, ENT_QUOTES, $conf["html_content_encoding"])."</i>\") ".$app->tform->wordbook['error_srv_out_of_range']."<br>\r\n";
		if($port < 0 || $port > 65535) $error .= $app->tform->wordbook['port_txt']." (\"<i>".htmlentities($port, ENT_QUOTES, $conf["html_content_encoding"])."</i>\") ".$app->tform->wordbook['error_srv_out_of_range']."<br>\r\n";

		$error .= $this->validate_field($target, "SRV target", $zoneid, 0);

		$data = (int)$weight." ".(int)$port." ".$target;
		return $error;
	}

	function is_integer($value, $fieldname, $zero_allowed = 0){
		global $app, $conf;

		$error = '';

		if($app->functions->intval($value, true) != $value || !is_numeric($value)) $error .= $fieldname." ".$app->tform->wordbook['error_must_be_integer']."<br>\r\n";
		if($value > 2147483647) $error .= $fieldname." ".$app->tform->wordbook['error_must_not_be_greater_than_2147483647']."<br>\r\n";
		if(!$zero_allowed){
			if($value <= 0) $error .= $fieldname." ".$app->tform->wordbook['error_must_be_positive']."<br>\r\n";
		} else {
			if($value < 0) $error .= $fieldname." ".$app->tform->wordbook['error_must_not_be_negative']."<br>\r\n";
		}

		return $error;
	}

	function validate_rr(&$rr){
		global $app, $conf;

		$error = '';

		$tmp_rr = $rr;
		foreach($tmp_rr as $key => $val){
			$rr[$key] = trim($val);
		}
		unset($tmp_rr);

		$error .= $this->validate_field($rr['name'], 'Name', $rr['zone'], 1);

		switch ($rr['type']) {
		case "A":
			$ip_parts = explode(".", $rr['data']);
			if(count($ip_parts) != 4){
				$error .= $app->tform->wordbook['data_txt']." ".$app->tform->wordbook['error_a']."<br>\r\n";
			} else {
				for($n = 0; $n < 4; $n++){
					$q = $ip_parts[$n];
					if(!is_numeric($q) || (int)$q < 0 || (int)$q > 255 || trim($q) !== $q) $error .= $app->tform->wordbook['data_txt']." ".$app->tform->wordbook['error_a']."<br>\r\n";
				}
			}
			$rr['data'] = (int)$ip_parts[0].".".(int)$ip_parts[1].".".(int)$ip_parts[2].".".(int)$ip_parts[3];
			break;
		case "AAAA":
			$valid_chars = "ABCDEFabcdef1234567890:";

			if(strspn($rr['data'], $valid_chars) != strlen($rr['data'])) $error .= $app->tform->wordbook['data_txt']." ".$app->tform->wordbook['error_aaaa']."<br>\r\n";
			break;
		case "ALIAS":
			$error .= $this->validate_field($rr['data'], 'Data', $rr['zone'], 0);
			break;
		case "CNAME":
			$error .= $this->validate_field($rr['data'], 'Data', $rr['zone'], 0);
			break;
		case "HINFO":
			if(!strchr($rr['data'], ' ')) $error .= $app->tform->wordbook['data_txt']." ".$app->tform->wordbook['error_hinfo']."<br>\r\n";
			break;
		case "MX":
			$error .= $this->validate_field($rr['data'], 'Data', $rr['zone'], 0);
			$error .= $this->is_integer($rr['aux'], $app->tform->wordbook['aux_txt'], 1);
			break;
		case "NS":
			$error .= $this->validate_field($rr['data'], 'Data', $rr['zone'], 0);
			break;
		case "PTR":
			$error .= $this->validate_field($rr['data'], 'Data', $rr['zone'], 0);
			if(substr($rr['data'], -1) != '.') $error .= $app->tform->wordbook['data_txt']." ".$app->tform->wordbook['error_ptr']."<br>\r\n";
			break;
		case "RP":
			$error .= $this->validate_rp_data($rr['data'], $rr['zone']);
			break;
		case "SRV":
			$error .= $this->validate_srv_data($rr['data'], $rr['zone']);
			$error .= $this->is_integer($rr['aux'], $app->tform->wordbook['aux_txt'], 1);
			break;
		case "TXT":
			break;
		}

		$error .= $this->is_integer($rr['ttl'], $app->tform->wordbook['ttl_txt']);


		return $error;
	}

	function validate_soa(&$soa){
		global $app, $conf;

		$error = '';

		$tmp_soa = $soa;
		foreach($tmp_soa as $key => $val){
			if($key != 'active') $soa[$key] = trim($val);
		}
		unset($tmp_soa);

		if($soa['origin'] == '') $error .= $app->tform->wordbook['origin_txt']." ".$app->tform->wordbook['error_empty']."<br>\r\n";
		if(substr($soa['origin'], -1) != '.') $error .= $app->tform->wordbook['origin_txt']." ".$app->tform->wordbook['error_dot']."<br>\r\n";
		$error .= $this->validate_field($soa['origin'], "Zone origin", $soa['id'], 0);

		$error .= $this->is_integer($soa['ttl'], $app->tform->wordbook['ttl_txt']);

		if($soa['ns'] == '') $error .= $app->tform->wordbook['ns_txt']." ".$app->tform->wordbook['error_empty']."<br>\r\n";
		$error .= $this->validate_field($soa['ns'], "Name server", $soa['id'], 0);

		if($soa['mbox'] == '') $error .= $app->tform->wordbook['mbox_txt']." ".$app->tform->wordbook['error_empty']."<br>\r\n";
		$error .= $this->validate_field($soa['mbox'], "Admin email", $soa['id'], 0);

		$error .= $this->is_integer($soa['refresh'], $app->tform->wordbook['refresh_txt']);

		$error .= $this->is_integer($soa['retry'], $app->tform->wordbook['retry_txt']);

		$error .= $this->is_integer($soa['expire'], $app->tform->wordbook['expire_txt']);

		$error .= $this->is_integer($soa['minimum'], $app->tform->wordbook['minimum_txt']);

		return $error;
	}

	function increase_serial($serial){
		global $app, $conf;

		// increase serial
		$serial_date = $app->functions->intval(substr($serial, 0, 8));
		$count = $app->functions->intval(substr($serial, 8, 2));
		$current_date = date("Ymd");
		if($serial_date >= $current_date){
			$count += 1;
			if ($count > 99) {
				$serial_date += 1;
				$count = 0;
			}
			$count = str_pad($count, 2, "0", STR_PAD_LEFT);
			$new_serial = $serial_date.$count;
		} else {
			$new_serial = $current_date.'01';
		}
		return $new_serial;
	}

	function validate_ip($field_name, $field_value, $validator) {
		global $app;

		$errorMessage = '';

		if($validator['allowempty'] != 'y') $validator['allowempty'] = 'n';
		if($validator['allowempty'] == 'y' && $field_value == '') {
			//* Do nothing
		} elseif ($field_value == 'any' && $field_name != "also_notify") {
			//* Do nothing
		} else {
			//* Check if its a IPv4 or IPv6 address/range
			if(isset($validator['separator']) && $validator['separator'] != '') {
				//* When the field may contain several IP addresses, split them by the char defined as separator
				$field_value_array = explode($validator['separator'], $field_value);
			} else {
				$field_value_array[] = $field_value;
			}
			// Check if it's a valid input
			foreach($field_value_array as $field_value) {
				// Check if the IP is valid without range
				$subnet = '';
				$ip = trim($field_value);
				if(strpos($ip, '/') !== false) {
					list($ip, $subnet) = explode('/', $ip, 2);
					$ip = trim($ip);
				}
				if(function_exists('filter_var')) {
						if(!filter_var($ip, FILTER_VALIDATE_IP)) {
						$errmsg = $validator['errmsg'];
						$errorMessage .= $app->tform->lng($errmsg)."<br />\r\n";
					}
				} else $this->errorMessage .= "function filter_var missing <br />\r\n";
				// Check if the range is valid
				if ($subnet !== '') {
					if (!is_numeric($subnet)) {
						$errmsg = $validator['errmsg'];
						$errorMessage .= $app->tform->lng($errmsg)."<br />\r\n";
					}
					elseif (filter_var($ip, FILTER_VALIDATE_IP, FILTER_FLAG_IPV6)) {
						if ($subnet < 1 || $subnet > 128) {
							$errmsg = $validator['errmsg'];
							$errorMessage .= $app->tform->lng($errmsg)."<br />\r\n";
						}
					}
					elseif ($subnet < 1 || $subnet > 32) {
						$errmsg = $validator['errmsg'];
						$errorMessage .= $app->tform->lng($errmsg)."<br />\r\n";
					}
				}
			}
		}
		return $errorMessage;
	}

}