Codezwiz >> Forums >> General PHP Nuke Help >> chimage - image protection causing errors ... help please.

Hi there,

Yesterday my ISP disabled my site because they thought this script was causing problems with their server.

Here is the extract from my error.log ...

-----------------------------------------

[05-Feb-2006 17:01:33] PHP Warning: getimagesize(/home/bubworld/.foobar/trends.gif) [<a href='function.getimagesize'>function.getimagesize</a>]: failed to open stream: No such file or directory in /home/bubworld/public_html/nuke/chimage.php on line 48
[05-Feb-2006 17:01:33] PHP Warning: Cannot modify header information - headers already sent by (output started at /home/bubworld/public_html/nuke/chimage.php:48) in /home/bubworld/public_html/nuke/chimage.php on line 59

-----------------------------------------

Here's the script which serves up the images. The images live in a directory outside the webserver root so they cannot be accessed directly.

Sometimes, the images havent been fully created (they update every minute or so) - so they're incomplete when they're requested by this script.

[B]How can I check the images are complete before attempting to serve them and therefore prevent the errors ?[/B]

Thanks, Bub.

-----------------------------------------

<?
/*
CHImageGuard (PHP version) 1.01
*/

$imagedir = "/home/mysite/mystor/" ;

$validprefixes = array (
"www.bbc.co.uk") ;

// --- YOU NEED NOT MODIFY ANYTHING AFTER THIS LINE ---

function isreferrerokay ( $referrer, $validprefixes )
{
$validreferrer = 0 ;
$authreferrer = current( $validprefixes );
while ($authreferrer) {
if (eregi( "^https?://$authreferrer/", $referrer )) {
$validreferrer = 1 ;
break ;
}
$authreferrer = next( $validprefixes );
}
return $validreferrer ;
}

//----------------------- main program -----------------------

$image = $_GET['image'] ;
$referrer = getenv( "HTTP_REFERER" );

if (isset($_GET['image'])) {

if (empty($referrer) ||
isreferrerokay( $referrer, $validprefixes )) {

$imagepath = $imagedir . $image ;

$imageinfo = getimagesize( $imagepath );
if ($imageinfo[2] == 1) {
$imagetype = "gif" ;
}
elseif ($imageinfo[2] == 2) {
$imagetype = "jpeg" ;
}
elseif ($imageinfo[2] == 3) {
$imagetype = "png" ;
}
else {
header( "HTTP/1.0 404 Not Found" );
exit ;
}

header( "Content-type: image/$imagetype" );
@readfile( $imagepath );

}
else {

if (isset($email)) {
mail( $email, "Bandwidth Theft Alert",
"WARNING:\n\n$referrer\ntried to access\n$image\n",
"From: CHImageGuard <$email>" );
}
header( "HTTP/1.0 404 Not Found" );
}
}
else {
header( "Location: $homepage" );
}

?>

Try this one:

<?
/*
CHImageGuard (PHP version) 1.01
*/

$imagedir = "/home/mysite/mystor/";

$validprefixes = array("www.bbc.co.uk");

// --- YOU NEED NOT MODIFY ANYTHING AFTER THIS LINE ---

function isreferrerokay($referrer, $validprefixes) {
$validreferrer = 0;
$authreferrer = current($validprefixes);
while ($authreferrer) {
   if (eregi("^https?://$authreferrer/", $referrer)) {
      $validreferrer = 1;
      break;
   }
   $authreferrer = next($validprefixes);
}
return $validreferrer;
}

//----------------------- main program -----------------------

$image = $_GET['image'];
$referrer = getenv("HTTP_REFERER");

if (isset($_GET['image'])) {
if (empty($referrer) || isreferrerokay($referrer, $validprefixes)) {
   $imagepath = $imagedir.$image;
   $imageinfo = @getimagesize($imagepath);
   if ($imageinfo[2] == 1) {
      $imagetype = "gif" ;
   } elseif ($imageinfo[2] == 2) {
      $imagetype = "jpeg" ;
   } elseif ($imageinfo[2] == 3) {
      $imagetype = "png" ;
   } else {
      header("HTTP/1.0 404 Not Found");
      exit;
   }
   if (is_file($imagepath)) {
      header("Content-type: image/$imagetype");
      @readfile($imagepath);
} else {
      header("Location: $homepage");
exit;
}
} else {
   if (isset($email)) {
      mail($email, "Bandwidth Theft Alert", "WARNING:\n\n$referrer\ntried to access\n$image\n", "From: CHImageGuard <$email>");
   }
   header("HTTP/1.0 404 Not Found");
exit;
}
} else {
   header("Location: $homepage");
exit;
}

?>

What's the difference ?

That one checks to make sure it is a file before serving it.

if (is_file($imagepath)) {
   header("Content-type: image/$imagetype");
   @readfile($imagepath);
} else {
   header("Location: $homepage");
   exit;
}