<?php

namespace DDNS;

if (!is_callable('curl_init'))
	die('ERROR: This PHP script requires cURL to be installed.');

/* 
 *  
 *  CUSTOM DYNAMIC DNS SOLUTION FOR USE WITH CLOUDFLARE
 *  ===============================================================================================
 *  ===============================================================================================
 *  
 *  Christopher Pei
 *  ------------------------------------------
 *  	September	05, 2018			R1
 * 		November	27, 2018 			R2
 * 		November	28, 2018 			R3
 *  ===============================================================================================
 *  
 */


//	-------------------------------------------------------------------------------------------
//	SETTINGS
//	-------------------------------------------------------------------------------------------

//	API Credential Setup Instructions
//	===========================================================================================
//
//	Settings or organized in a tabular format with SETTING NAME on the left and VLUE on the right.
//	Please only edit the VALUE data/columns. When editing, please keep values inside the quotation-
//	marks ("") and do not remove any parentheses (()) or semi-colons (;).
//
//	------------------ Set Basic Options
//
//	Since this script may be publicly accessible on your web server, you can use the "DDNS_PASSWORD"
//	setting so that this string must be provided in order to access this script.
//
//	To access the script with the password, you use a web browser and access it as follows:
//
//		/ddns.php?psswd=56789
//
//	replacing "56789" with your DDNS Password. For example, if this script is located
//	on your webserver at "https://www.google.com/ddns.php" and your DDNS Password is
//	"4392", you would use your browser to access it as follows:
//
//				https://www.google.com/ddns.php?passwd=4392
//
//	Alternatively, if you wish to disable this security feature, leave the VALUE empty
//	(nothing between the quotation marks). Then you can access the script just via the
//	name itself. In the example above but without a DDNS Password, you would access it
//	as follows:
//
//				https://www.google.com/ddns.php
//
//
//	-------------------------------------------------------------------------------------------
//	------------------ SETTING NAME -------------------- VALUE --------------------------------
//	-------------------------------------------------------------------------------------------
define(__NAMESPACE__ . '\DDNS_PASSWORD',				'56789'									);
//
//
//
//	------------------ Set Your API Credentials
//
//	For many of these settings, you will have access to your CloudFlare account to acquire the
//	appropriate information.
//
//		1). Login to your CloudFlare account at:	https://dash.cloudflare.com/login
//
//		2). If applicable, select your account.
//
//		3). If applicable, select the domain you wish to use.
//
//		4). Under the "Domain Summary" section, locate the "Zone ID". Copy this value and paste
//			this into the VALUE for the "CF_ZONE_ID" setting.
//
//		5). In the same section, click "Get your API Key". Scroll down the page and under the
//			"API Keys" locate the "Global API Key" and click "View". Copy this value and paste
//			this into the VALUE for the "CF_API_KEY" setting.
//
//		6). The e-mail address you use to login to CloudFlare is your API username. Provide
//			this into the VALUE for the "CF_API_USERNAME" setting.
//
//	-------------------------------------------------------------------------------------------
//	------------------ SETTING NAME -------------------- VALUE --------------------------------
//	-------------------------------------------------------------------------------------------
define(__NAMESPACE__ . "\CF_ZONE_ID",					"s40v9w8fbn0w49r84r8gw04954852784"		);
define(__NAMESPACE__ . "\CF_API_USERNAME",				"your_email@domain.com"					);
define(__NAMESPACE__ . "\CF_API_KEY",					"xk59gs4jg90d893i8560fg8wejdnci4869vvy"	);
//
//	------------------ Create The DNS Record
//
//		Now, if you have not already done so, it is time to create a subdomain on the domain
//		that you wish to use for the custom dynamic DNS:
//
//		1). Navigate to https://dash.cloudflare.com/websites and select the domain you wish to
//			use for the custom dynamic DNS service.
//
//		2). Go to the "DNS" section, and under the "Search" box, select "A" from the drop-down
//			menu, enter your desired subdomain in the "Name" field.
//
//		3).	Copy and past the value of the "Name" field into the VALUE for the "FQDN" setting.
//			Do not include ANY trailing slashes and do NOT include either "http://" or "https://"
//			in the setting value.
//
//		4). Enter any IP address into the "IPv4 address" field (even "1.2.3.4" is okay; this will
//			be updated by the script automatically later, so its current value is not relevant).
//
//		5). If this dynamic DNS is going to be used for HTTP traffic (such as a website), then you
//			can leave the "Automatic TTL" and orange cloud enabled to benefit from CloudFlare's
//			reverse proxy security. However, if this will be used for something else (such as FTP,
//			SSH, Remote Desktop, etc) then modify the TTL to "2 minutes" and DISABLE the orange
//			cloud. Disabling the orange cloud will disable CloudFlare's reverse proxy, which is
//			required for non-HTTP protocols.
//
//		6).	When finished, click the "Add Record" button.
//
//	-------------------------------------------------------------------------------------------
//	------------------ SETTING NAME -------------------- VALUE --------------------------------
//	-------------------------------------------------------------------------------------------
define(__NAMESPACE__ . "\FQDN",							"something.example.com"					);
//
//	------------------ Get The DNS Record ID
//
//	This is where it might seem funky. CloudFlare is somewhat "stupid" in the sense that it
//	provides no NORMAL way to get the ID of a DNS record, which is a unique ID that identifies
//	a particular DNS record for your website. The only way to do this is programmatically, via
//	their API.
//
//	For simplicity, I have programmed this ability directly into this script:
//
//		1). Please be sure that all other settings are already provided--- otherwise this script
//			cannot authenticate with the CloudFlare API to find the ID of your DNS record. The
//			VALUE of CF_ZONE_ID, CF_API_KEY, and CF_API_USERNAME must be provided. (Please see
//			the [Set Your API Credentials] section above for help).
//
//		2). Using a web browser of your choice, access this PHP script in the URL as follows:
//
//				/ddns.php?psswd=12345&dump=1
//
//			replacing "12345" with your DDNS Password. For example, if this script is located
//			on your webserver at "https://www.google.com/ddns.php" and your DDNS Password is
//			"4392", you would use your browser to access it as follows:
//
//				https://www.google.com/ddns.php?passwd=4392&dump=1
//
//			If your DDNS Password is disabled, access this PHP script in the URL as follows:
//
//				/ddns.php?dump=1
//
//			For example:
//
//				https://www.google.com/ddns.php?dump=1
//
//
//		3).	If successful, the script will output a long string. Please carefully copy and paste
//			the string into the VALUE for the "CF_DNS_RECORD_ID" setting.


//	-------------------------------------------------------------------------------------------
//	------------------ SETTING NAME -------------------- VALUE --------------------------------
//	-------------------------------------------------------------------------------------------
define(__NAMESPACE__ . "\CF_DNS_RECORD_ID",				"e67898768a9859c859845898b7897f09"		);
//
//
//	------------------ Miscellaneous Settings
//
//	If you wish to use CloudFlare's reverse proxy security, which will mask your your IP, set this
//	value to "true" (without quotations). Otherwise, set it to "false" (without quotations). Note
//	that the CloudFlare reverse proxy feature is currently for HTTP services only, and will not
//	work for other services, such as FTP, SSH, Remote Desktop, etc. A value of "true" is equivalent
//	to the "orange-cloud" DNS setting on your CloudFlare control panel, while a value of "false"
//	is equivalent of the "grey-cloud" DNS setting.
//	-------------------------------------------------------------------------------------------
//	------------------ SETTING NAME -------------------- VALUE --------------------------------
//	-------------------------------------------------------------------------------------------
define(__NAMESPACE__ . "\USE_CF_REV_PROXY", false );





//	--------------------------------------------------------------------------------------------
//	--------------------------------------------------------------------------------------------
//	--------------------------------------------------------------------------------------------
//	--------------------------------------------------------------------------------------------
//	------------- END OF SETTINGS - BE CAREFUL CHANGING ANYTHING BEYOND THIS POINT -------------
//	--------------------------------------------------------------------------------------------
//	--------------------------------------------------------------------------------------------
//	--------------------------------------------------------------------------------------------
//	--------------------------------------------------------------------------------------------







//	VARS

$visitor_ip			= $_SERVER['HTTP_CF_CONNECTING_IP']??$_SERVER['REMOTE_ADDR'];
$j 					= new \stdClass();

//	FUNCTIONS

//	@BRIEF		Creates and outputs the JSON response.
//	@RETURNS	Does not return a value.
function CREATE_JSON_RESPONSE(&$r){
	
	header('Content-Type: application/json');
	echo json_encode($r, JSON_FORCE_OBJECT);
}

//	@BRIEF		Checks DDNS Password with provided password.
//	@RETURNS	Returns true if correct or disabled, and false if incorrect.
function CHECK_PASSWORD(){
	
	if (defined('DDNS\\DDNS_PASSWORD')){
		
		if (empty(DDNS_PASSWORD))
			return true;
		if (!strcmp($_REQUEST['passwd'], DDNS_PASSWORD))
			return true;
		return false;
	}
	
	return true;
}

//	@BRIEF		Checks if script is being called with a DUMP request.
//	@RETURNS	Returns true if it is or false otherwise.
function IS_DUMP_REQUEST(){
	
if (isset($_REQUEST['dump']) &&
	!empty($_REQUEST['dump']) &&
	($_REQUEST['dump'] == 1 ||
	$_REQUEST['dump'] == "1")
	){
	
		if (!strcmp(FQDN, "something.example.com")){
			
			$j->success = false;
			$j->message = 'You must provide the domain you wish to use for the "FQDN" setting.';
			
			CREATE_JSON_RESPONSE($j);
			
			exit(0);
		}
		
		else return true;
	}
	
	return false;
}

//	@BRIEF		Creates and DUMP of the DNS data to output the DNS Record ID.
//	@RETURNS	Does not return a value.
function DUMP(){
	
	try{
		
		//	Send the request.
		$ch = curl_init();

		curl_setopt($ch, CURLOPT_URL, "https://api.cloudflare.com/client/v4/zones/" . CF_ZONE_ID . "/dns_records?type=A&name=" . FQDN . "&match=all");
		curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
		curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "GET");


		$headers = array();
		$headers[] = "X-Auth-Email: " . CF_API_USERNAME;
		$headers[] = "X-Auth-Key: " . CF_API_KEY;
		$headers[] = "Content-Type: application/json";
		curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);

		$response = curl_exec($ch);
		if (curl_errno($ch)){
			
			$j->success = false;
			$j->message = 'cURL encountered a problem.';
			$j->cURL_err = curl_error($ch);
			
			curl_close ($ch);
			CREATE_JSON_RESPONSE($j);
			
			exit(0);
		}
		
		curl_close ($ch);
		
		//	Parse the DNS Record ID.
		$r = json_decode($response, true);
		if (isset($r['result'][0]['id'])){
			
			$j->success = true;
			$j->message = 'Please copy the "id" value below into the VALUE for the CF_DNS_RECORD_ID settings. Be sure to copy only the value below within the quotation marks.';
			$j->id = $r['result'][0]['id'];
			CREATE_JSON_RESPONSE($j);
			
			exit(0);
		}
		
		else{
			
			$j->success = false;
			$j->message = 'CloudFlare did not provide a valid response. Please ensure that you have provided correct details for all settings and try again.';
			CREATE_JSON_RESPONSE($j);
			exit(0);
		}
	}catch(Exception $e){
		
		$j->success = false;
		$j->message = 'A fatal exception occurred.';
		$j->exception = $e;
		$j->cURL_err = curl_error($ch);
		curl_close ($ch);
	}

}

//	@BRIEF		Updates the DNS record with the visitor's IP.
//	@RETURNS	Does not return a value.
function DNS_UPDATE($new_ip){
	
	try{
		
		//	Send the request.
		$ch = curl_init();
		curl_setopt($ch, CURLOPT_URL, "https://api.cloudflare.com/client/v4/zones/" . CF_ZONE_ID . "/dns_records/" . CF_DNS_RECORD_ID);
		curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
		//	CloudFlare is fucking retarded and bitches about this as "malformed JSON, error 6007".
		//curl_setopt($ch, CURLOPT_POSTFIELDS, "{\"type\":\"A\",\"name\":\"" . FQDN . "\",\"content\":\"" . $new_ip . "\",\"ttl\":120,\"proxied\":" . USE_CF_REV_PROXY . "}");
		if (USE_CF_REV_PROXY)
			curl_setopt($ch, CURLOPT_POSTFIELDS, "{\"type\":\"A\",\"name\":\"" . FQDN . "\",\"content\":\"" . $new_ip . "\",\"ttl\":120,\"proxied\":true}");
		else
			curl_setopt($ch, CURLOPT_POSTFIELDS, "{\"type\":\"A\",\"name\":\"" . FQDN . "\",\"content\":\"" . $new_ip . "\",\"ttl\":120,\"proxied\":false}");
		curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "PUT");


		$headers = array();
		$headers[] = "X-Auth-Email: " . CF_API_USERNAME;
		$headers[] = "X-Auth-Key: " . CF_API_KEY;
		$headers[] = "Content-Type: application/json";
		curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);

		$response = curl_exec($ch);
		if (curl_errno($ch)){
			
			$j->success = false;
			$j->message = 'cURL encountered a problem.';
			$j->cURL_err = curl_error($ch);
			
			curl_close ($ch);
			CREATE_JSON_RESPONSE($j);
			
			exit(0);
		}
		
		curl_close ($ch);
		
		//	Parse the DNS Record ID.
		$r = json_decode($response, true);
		if (isset($r['success'])){
			
			//	Uncomment these lines for debugging.
			// header('Content-Type: application/json');
			// echo json_encode($r, JSON_FORCE_OBJECT);
			// exit(0);
			
			if ($r['success'] == true){
			
				$j->success = true;
				$j->message = 'The [' . FQDN . '] DNS record was successfully updated to point to [' . $new_ip . '].';
				CREATE_JSON_RESPONSE($j);
				
				exit(0);
			}
			
			$j->success = false;
			$j->message = 'CloudFlare reported an error. Please ensure that you have provided correct details for all settings and try again.';
			// $j->id = $r['result'][0]['id'];
			CREATE_JSON_RESPONSE($j);
			
			exit(0);
		}
		
		else{
			
			$j->success = false;
			$j->message = 'CloudFlare did not provide a valid response. Please ensure that you have provided correct details for all settings and try again.';
			CREATE_JSON_RESPONSE($j);
			exit(0);
		}
	}catch(Exception $e){
		
		$j->success = false;
		$j->message = 'A fatal exception occurred.';
		$j->exception = $e;
		$j->cURL_err = curl_error($ch);
		curl_close ($ch);
	}

}





//	SCRIPT

//	---------------------------------------------------------

if (CHECK_PASSWORD()){
	
	
	if (IS_DUMP_REQUEST()){
	
		DUMP();
		exit(0);
	}
	
	DNS_UPDATE($visitor_ip);
	
	exit(0);
}


$j->success = false;
$j->message = 'The DDNS Password is incorrect. Check the "passwd" value and try again.';
CREATE_JSON_RESPONSE($j);

exit(0);

//	---------------------------------------------------------