Peenie Wallie

My apache mod_rewrite commands:

RewriteEngine on
RewriteCond %{HTTP_REFERER} !^$
RewriteCond %{HTTP_REFERER} !^http(s)?://(www\.)?peeniewallie.com [NC]
RewriteRule \.(jpg|bmp|png|gif)$ http://www.peeniewallie.com/imagehot/pw.jpeg [NC,L]

These worked flawless for IE and for Chrome. They would not work for my 2 of my desktops running Firefox. To make matters worse, I was running two different releases of Firefox on the desktops. Firefox 3.5.7 on one desktop. Firefox 2.0.0.20 on the other desktop. Neither of them worked. Both of the desktops running different versions of Firefox were able to successfully hotlink to my images all day long. Arrghh.

Then, I tried my laptop. Surfing the internet wirelessly, I was able to get Firefox on the laptop (Version 3.5.7) to follow the Apache mod_rewrite redirects successfully. It successfully redirected to the "hotlink" image. So, I thought, maybe it was because of the way I was connected into the network. Maybe the fact that I was coming into the network wirelessly somehow made a difference. So, I connected the laptop directly into the network with ethernet Cat 6 cable and turned off my wireless card. Still worked the same. No change in performance. Firefox works fine on the laptop...it follows the Apache redirects. The two desktops with Firefox ignore the Apache redirects all day long.

Then, I decided to try another desktop. (I'm not going to lie to you - I've got a lot of computers at the house. More than I can manage, obviously.) On the third desktop, Firefox (Version 3.5.7) performed properly....it followed the Apache redirects, as did the laptop.

So, now I'm trying to figure out what's going on. I'm starting to paint this issue into a corner. Basically, the only browser that has any issue at all out of IE, Chrome, and Firefox - is Firefox. And it's only a problem on 2 out of 4 computers. The clot thickens.

So, I'm hammering away on these two desktops, trying to figure out why they will hotlink images that no other browser on earth will hotlink, when I realize that part of my problem is related to cache. Now, every time I attempt a hotlink test, I delete all of the cache files in Firefox. But, for some reason, when I stop my apache web server, this website still shows a valid hotlink to my image. But, now I know it's lying to me because Apache's shut down. So, I know I have a cache issue. Gradually, I realize that Firefox 3.x doesn't handle cache files very well. I finally solve this issue by typing in "about:config" into the address bar and changing the setting "browser.cache.disk.enable" to "false" and setting the "browser.cache.check_doc_frequency" = 1. Basically, this means...."Dear God Please Stop Caching Files!" (This was not previously a problem with FireFox, but starting with release 3.x, it became a problem.)

So, now, at least, I'm not fighting with Firefox's faulty cache issue any more. That problem is out of the way. Still, I mean, certainly we do still have a major hotlink issue, but at least we know what we're dealing with, at this point. I'm not getting feedback from 3rd party websites that they can hotlink to my images when my webserver is down. We're past that, anyway.

I have spent some time digging through my Apache log files. I've done that. And I have noticed that I have a slew of "blocked referrers" in the log. Now, I'm not clear why this is. But I have noticed it. I've stumbled across a few websites that talk about blocked referrers and how that can occur. Apparently, it can be caused by a variety of issues including, but not limited to, typing in the URL directly, following a bookmark, 3rd party software, etc, etc.

I had some idea that, perhaps, my issue was related somehow to blocked referrers. I even convinced myself that AVG was blocking my referrers. Maybe the AVG LinkScanner, or the ActiveShield, or something else. I uninstalled AVG, but still, I had the problem where Firefox is hotlinking to images on 2 of my desktops.

And, I find myself in this odd position of trying to fix my 2 Firefox installs so that they won't hotlink my images. But, obviously, this makes no sense. I mean, OK. So, let's say, for argument's sake, that I uninstall and reinstall Firefox and it works. These 2 installs of Firefox start performing better, and they follow my Apache redirects. What then? I mean, the fact they they're showing hotlinked images right now is a huge, glaring problem. And fixing Firefox isn't necessarily the answer. Sure, I can probably make Firefox quit hotlinking my images, but what then? Aren't I really just papering over a glaring problem - namely that others out there could be (and probably are) hotlinking to my images right now?

But this is where I am. For now, I'm trying to fix Firefox. Trying to paper over this little problem. Trying to solve one issue at a time. And I'm thinking....Firefox...Firefox....blocked referrers....why would Firefox be different on these two computers. And then, it hits me. Out of the clear blue sky it hits me like a ton of bricks. Crazedlist. Not Craigslist.org. Crazedlist.org. Search Craiglist like a madman. But, before you can, you have to do a little trick. You have to go to "about:config" and change the "network.http.sendRefererHeader" variable from a "2" to a "1". Voila. That was it. On the two desktops, I'd reconfigured Firefox not to send Referrer Headers. So, I was blocking my "referrer" headers on my http requests with those two installs of Firefox. Because the http requests came in without any "referrer headers", they were not blocked. Now, certainly, you can configure the Apache mod_rewrite so that you redirect the blocked referrers, but there are apparently a few arguments against it.

I've not decided how I'll change my Apache Mod_Rewrite directives just yet. RIght now, I'm happy that I've solved the mystery of why Firefox appeared to be ignoring my Apache redirects. OK - technically, it wasn't ignoring my redirects, but it was blocking my http referrer headers without my knowledge, which cause the browser to behave in a counter-intuitive manner. :)