php file prompts for download

mikeafl

I have a client site that displays PDFs in an i-frame. Occasionally when navigating to another php page from the page with the i-frame, instead of the php being parsed, the user is prompted to download the php file. It seems to happen more often in Mozilla, but does happen in MSIE also. There is no consistency to the problem- sometimes the pages display ok and other times they don't, going from the same pdf to the same php page.

I grabbed the headers from when the page works and when it doesn't. When the download prompt appears, there is nothing after this header line:

HTTP/1.x 200 OK

Here's the setup:
Linux RHE4
Apache/2.0.52 (Red Hat)
PHP 4.3.9
Running SSL

Here's the entire header:

this part is returned every time
GET /client_admin.php HTTP/1.1
Host: online.docublue.com
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.8.0.7) Gecko/20060909 Firefox/1.5.0.7
Accept: text/xml,application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,/;q=0.5
Accept-Language: en-us,en;q=0.5
Accept-Encoding: gzip,deflate
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
Keep-Alive: 300
Connection: keep-alive
Referer: https://online.docublue.com/showdoc.php
Cookie: xxxxxxxxxxxxx; PHPSESSID=xxxxxxxx

HTTP/1.x 200 OK

this part is returned when the page works as expected, but not on requests when the download prompt appears *

Date: Tue, 17 Oct 2006 15:37:56 GMT
Server: Apache/2.0.52 (Red Hat)
X-Powered-By: PHP/4.3.9
Expires: Thu, 19 Nov 1981 08:52:00 GMT
Cache-Control: no-store, no-cache, must-revalidate, post-check=0, pre-check=0
Pragma: no-cache
Content-Length: 3072
Keep-Alive: timeout=15, max=100
Connection: Keep-Alive
Content-Type: text/html; charset=ISO-8859-1

Any help with this would be greatly appreciated- it's making me nuts (my client isn't real thrilled either!) I've checked the code and the server config- dunno what else to be looking at.

dalecosp

What can you tell us about the physical configuration of the server? I assume you control it, it's not behind a load-balancer, transparent proxy, (NATD(?) gee, wonder why I wrote that ... must be grasping at straws also....)

I've checked the code and the server config- dunno what else to be looking at.

The word "logfiles" pops to mind. 😃

Any chance of a RedHat, PHP, or Apache bug? I'd suspect Apache first, not because of reputation, but it seems odd that the server seems to occasionally "crap out" before sending the complete (proper?) header info.

Good luck, hope you find something ... sounds rather frustrating.

mikeafl

Thanks for your response-

Only 'unusual' thing about the physical config is that the server sits behind a wireless router and I'm using port forwarding to handle web and other requests (my client wants the server in his office).

Checked the logs- no clue there. Apache error log shows nada, access log shows a valid, answered request whether the file is parsed or not-

*** this request worked- file was parsed and page was served:
69.165.225.119 - - [17/Oct/2006:17:13:49 -0400] "GET /user_admin.php HTTP/1.1" 200 4431 "https://online.docublue.com/showdoc.php" "Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.8.0.7) Gecko/20060909 Firefox/1.5.0.7"

*** this request resulted in a prompt to download user_admin.php:
69.165.225.119 - - [17/Oct/2006:17:16:49 -0400] "GET /user_admin.php HTTP/1.1" 200 4431 "https://online.docublue.com/showdoc.php" "Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.8.0.7) Gecko/20060909 Firefox/1.5.0.7"

They look exactly the same to me! 😕

Even checked the ssl logs (no stone unturned).

This only seems to happen after viewing an inline PDF- I set headers in an i-framed page to display the PDF. It's when navigating away from that page that the error occurs, but only occasionaly. Sometimes it works fine, and sometimes not. The intermittent problem doesn't seem related to the PDF that was viewed or the page that was requested after- it works intermittently going from the same PDF going to the same page.

This is the header code from the PDF display i-frame ($doc is the file location of the requested PDF):

	header("Pragma: public");
	header("Expires: Mon, 26 Jul 1997 05:00:00 GMT");
	header("Last-Modified: " . gmdate("D, d M Y H:i:s") . " GMT");
	header("Cache-Control: must-revalidate");
	header("Content-type: application/pdf");
	header("Content-Length: ".filesize($doc));
	header("Content-disposition: inline; filename=$doc");
	header("Accept-Ranges: ".filesize($doc));
	readfile($doc);

I don't mess with the headers on the request that's not working, but it seems there may be some connection, since it's only leaving this page that causes the error.