Downloading from SourceForge just gives me 1px gifs

houchin · 08-06-2003, 10:43 PM

Hi all,

I've been having a bit of a download problem, and it's getting worse, so I figure I better determine what's going on.

Whenver I try and download anything from sourceforge (pretty much anything from http://prdownloads.sourceforget.net/) from anywhere but my work internet connection, all I get back is a 1 pixel gif.

If I go to work and access it through our corporate proxy, everything works just fine.

For a while, this was just related to source forge, but lately, it's been happening with a few other places, such as http://invisionboard.com/download.cgi

I've seen this behaviour when connected at home to RoadRunner through either wireless or ethernet, and at a few hotels when connected through wireless.

To verify that it's not a browser problem, I tried using curl, ensuring that I had no .curlrc file to screw things up, and I still get that 1-pixel gif.

I'm running NetBarrierX, but the settings there don't change between home and work, so I don't think it's that.

Any suggestions would be greatly appreciated!
Thanks,
Scott

hayne · 08-07-2003, 12:00 AM

Are you using the same machine & same user account at home & at work? (i.e. a laptop?)

Is this something that happens all the time with certain sites? If so, tell us the URL that you are failing on so we can try it.

What happens if you disble your firewall? Does it work then?

houchin · 08-07-2003, 07:22 AM

Same machine, same user account, just sleep between home and work. I've tried disabling the firewall and that didn't help. It's a PowerBook G4/550 running 10.2.6

Here's a URL that's failing now:
http://www.invisionboard.com/download.cgi

The fact that the problem shows up with curl with no local proxies stronly points me to that it's either the firewall (which I've ruled out by disabling it) or something upstream somehow.

hayne · 08-07-2003, 10:47 AM

Quote:


	Originally posted by houchin Here's a URL that's failing now: http://www.invisionboard.com/download.cgi

Umm, that link gives me an HTML page - i.e. it is not a download link. There are links on that page that lead to a download link (after 2 more pages and a licence agreement). Please post the link which is not working for you. Or maybe I'm not understanding something.

houchin · 08-09-2003, 08:23 PM

That is the link that is not working. When I access that link, or anything from the sourceforge download pages, I get not the download or not the proper web page, but a 1 pixel gif.

Right now, If I do the following in the terminal:

curl -o foo http://www.invisionboard.com/download.cgi

I get 43 bytes of data, which when I view it is a 1 pixel gif.

hayne · 08-10-2003, 12:24 AM

Quote:


	Originally posted by houchin Right now, If I do the following in the terminal: curl -o foo http://www.invisionboard.com/download.cgi I get 43 bytes of data, which when I view it is a 1 pixel gif.

Okay, I know that my "right now" is several hours after the time when you tried it, but it works fine for me. Can you please clarify whether these links sometimes work for you - i.e. is the problem intermittent or do you always have the same problem with certain sites?

I thinkyou need to get some lower-level info to be able to see what is happening. Have you got 'fink' set up on your machine? If so, please download 'tcpflow' and then we can discuss how you can use that or some other low-level tool to see what is happening in the communications between your Mac and these web sites that don't work for you. If you don't have fink set up, we can probably manage with 'tcpdump' which is already installed on your system.

AKcrab · 08-10-2003, 03:36 AM

Quote:


	Originally posted by houchin I get 43 bytes of data, which when I view it is a 1 pixel gif.

Sounds like a firewall/privoxy replacement...

/grasping at straws.

darkpaw · 08-10-2003, 06:41 AM

Just to add my weight behind the original poster...

I have exactly the same problem. I run NetBarrierX too, but even disabling the kext so it doesn't run at startup, does not help at all. So, it can't be NB causing the problem.

There are many URLs that give me the same 1px gif image. Anything from sourceforge, and anything with a "?download" at the end of it does it.

Even using different browsers doesn't help. Safari v1.0, IE 5.2.3, Mozilla 1.3, NS 7.1. None seem to work.

It has to be some other sort of problem causing it. I have disabled the OS X firewall too.

Any ideas?

hayne · 08-10-2003, 10:53 AM

Now that there are two of you with the same strange problem and both of you are using NetBarrierX, it seems more and more likely that NetBarrierX is causing the problem. I know that you (darkpaw) said you disabled the kernerl extension for NetBarrierX but maybe some other part of it is still active.
I would recommend uninstalling it completely as a test.

But a more inofrmative route would be to run one of the low-level network tools as I recommended earlier and see exactly what is happening with your HTTP requests. That should tell us very quickly whether it is NetBarrier related or not.

To do this, first start a tcpdump or tcpflow session in a Terminal window. I prefer tcpflow (available via fink) - it is easier to interpret the results. You would run tcpflow with the following command:
sudo tcpflow -i en0 -c > my_output
where the ">" acts to capture the output from tcpflow into a file (my_output)
and where the "en0" is what you would use for an Ethernet connection - for Airport, use "en1".

Then use your web browser as usual and click on the link.

Finally, stop the tcpflow in Terminal by holding down Ctrl and pressing the C key (i.e. control-C) and look at the file with any text editor. Copy & paste the contents of the file here so we can analyze it.

darkpaw · 08-10-2003, 01:40 PM

Quote:


	Originally posted by hayne I know that you (darkpaw) said you disabled the kernerl extension for NetBarrierX but maybe some other part of it is still active. I would recommend uninstalling it completely as a test.

Done. Still get the same problem

Quote:


	To do this, first start a tcpdump or tcpflow session in a Terminal window. I prefer tcpflow (available via fink)

I don't want to install fink on my system, so can you tell em the syntax for the other command so I can send you that output instead?

Thanks.

hayne · 08-10-2003, 02:16 PM

Before we get into using the lower-level network tools (like tcpdump), it occurs to me that maybe we can see something useful if we use some of the debugging options to 'curl'.

Please try doing:

/usr/bin/curl -v -i http://www.invisionboard.com/download.cgi

and then copy and paste the output into this forum so we can all see it.

Of course, first check that the above URL is one that you are having troubles with when used in a web browser.

houchin · 08-10-2003, 02:28 PM

Ok, seeing another user that was also using NetBarrier X caused me to look deeper there.

The problem was not the firewall portion of the product but the privacy portion of the product. Go into NBX and hit the privacy icon. Then click on the banner tab.

NBX is trying to block banner ads, and its catching a lot of other stuff was well, at least with the default set of filters.

I turned this off, and things are all better now.

I had done the curl tests before, and since I only had the problem on en1, not en0, I figured it wasn't this. However, it appears that there is a possible problem with NetBarrier in that at least portions of it do not secure all of you network interfaces.

AKcrab · 08-10-2003, 04:19 PM

Quote:


	Originally posted by AKcrab Sounds like a firewall/privoxy replacement... /grasping at straws.

Do I win?

darkpaw · 08-10-2003, 08:50 PM

Then why doesn't it work when I uninstall NetBarrier???

Maybe yours is fixed, but what about mine?

houchin · 08-10-2003, 08:57 PM

My only thought was that uninstalling NetBarrier just uninstalled the app, but was not perfect about deinstalling the firewall and filtering rules, especially since NBX is really just a front end to ipfw.

I suggest reinstalling NBX and just turning off the filtering.

hayne · 08-10-2003, 11:47 PM

Quote:


	Originally posted by houchin My only thought was that uninstalling NetBarrier just uninstalled the app, but was not perfect about deinstalling the firewall and filtering rules, especially since NBX is really just a front end to ipfw.

Yes, that seems likely.
You can check what rules are currently operative via the following command in Terminal:

sudo ipfw list

You can remove all rules via the following command:

sudo ipfw flush

but there might be startup items left over from your firewall installation that would reinstate the firewall rules next startup.

darkpaw · 08-11-2003, 02:58 PM

Fixed

Yes, it *was* NBX. There is one little banner filter ad thing in there, thus:

URL Path contains ad.cgi

Guess what download.cgi contains too...

Well, it didn't explain why I uninstalled and still had the problem (the filter can't have been working), but I tried again, uninstalled, rebooted, reinstalled, works now.

Fix, re-enable the banner filter, just remove that one condition noted above.

Spiral Girl · 10-23-2007, 12:38 AM

houchin,

Thanks, eric2006 directed me to this link as I had the same problem with the GIF image. The Privacy, switching banner to off worked for me too.

S.

08-06-2003, 10:43 PM	#1
houchin Major Leaguer Join Date: Jan 2002 Location: Northern Virginai Posts: 294	Downloading from SourceForge just gives me 1px gifs Hi all, I've been having a bit of a download problem, and it's getting worse, so I figure I better determine what's going on. Whenver I try and download anything from sourceforge (pretty much anything from http://prdownloads.sourceforget.net/) from anywhere but my work internet connection, all I get back is a 1 pixel gif. If I go to work and access it through our corporate proxy, everything works just fine. For a while, this was just related to source forge, but lately, it's been happening with a few other places, such as http://invisionboard.com/download.cgi I've seen this behaviour when connected at home to RoadRunner through either wireless or ethernet, and at a few hotels when connected through wireless. To verify that it's not a browser problem, I tried using curl, ensuring that I had no .curlrc file to screw things up, and I still get that 1-pixel gif. I'm running NetBarrierX, but the settings there don't change between home and work, so I don't think it's that. Any suggestions would be greatly appreciated! Thanks, Scott

08-07-2003, 12:00 AM	#2
hayne Site Admin Join Date: Jan 2002 Location: Montreal Posts: 32,473	more info needed Are you using the same machine & same user account at home & at work? (i.e. a laptop?) Is this something that happens all the time with certain sites? If so, tell us the URL that you are failing on so we can try it. What happens if you disble your firewall? Does it work then?

08-10-2003, 06:41 AM	#8
darkpaw All Star Join Date: Apr 2002 Location: England Posts: 513	Just to add my weight behind the original poster... I have exactly the same problem. I run NetBarrierX too, but even disabling the kext so it doesn't run at startup, does not help at all. So, it can't be NB causing the problem. There are many URLs that give me the same 1px gif image. Anything from sourceforge, and anything with a "?download" at the end of it does it. Even using different browsers doesn't help. Safari v1.0, IE 5.2.3, Mozilla 1.3, NS 7.1. None seem to work. It has to be some other sort of problem causing it. I have disabled the OS X firewall too. Any ideas? __________________ http://www.keeponfighting.net - Fighting for animal rights http://www.darkpaw.co.uk http://www.needstuff.co.uk - Recycle your unwanted clutter for FREE! (UK only)

08-10-2003, 02:16 PM	#11
hayne Site Admin Join Date: Jan 2002 Location: Montreal Posts: 32,473	debugging options to 'curl' Before we get into using the lower-level network tools (like tcpdump), it occurs to me that maybe we can see something useful if we use some of the debugging options to 'curl'. Please try doing: /usr/bin/curl -v -i http://www.invisionboard.com/download.cgi and then copy and paste the output into this forum so we can all see it. Of course, first check that the above URL is one that you are having troubles with when used in a web browser.

08-10-2003, 02:28 PM	#12
houchin Major Leaguer Join Date: Jan 2002 Location: Northern Virginai Posts: 294	Problem solved! Ok, seeing another user that was also using NetBarrier X caused me to look deeper there. The problem was not the firewall portion of the product but the privacy portion of the product. Go into NBX and hit the privacy icon. Then click on the banner tab. NBX is trying to block banner ads, and its catching a lot of other stuff was well, at least with the default set of filters. I turned this off, and things are all better now. I had done the curl tests before, and since I only had the problem on en1, not en0, I figured it wasn't this. However, it appears that there is a possible problem with NetBarrier in that at least portions of it do not secure all of you network interfaces.

08-07-2003, 07:22 AM	#3
houchin Major Leaguer Join Date: Jan 2002 Location: Northern Virginai Posts: 294	Same machine, same user account, just sleep between home and work. I've tried disabling the firewall and that didn't help. It's a PowerBook G4/550 running 10.2.6 Here's a URL that's failing now: http://www.invisionboard.com/download.cgi The fact that the problem shows up with curl with no local proxies stronly points me to that it's either the firewall (which I've ruled out by disabling it) or something upstream somehow.

08-09-2003, 08:23 PM	#5
houchin Major Leaguer Join Date: Jan 2002 Location: Northern Virginai Posts: 294	That is the link that is not working. When I access that link, or anything from the sourceforge download pages, I get not the download or not the proper web page, but a 1 pixel gif. Right now, If I do the following in the terminal: curl -o foo http://www.invisionboard.com/download.cgi I get 43 bytes of data, which when I view it is a 1 pixel gif.

08-10-2003, 10:53 AM	#9
hayne Site Admin Join Date: Jan 2002 Location: Montreal Posts: 32,473	Now that there are two of you with the same strange problem and both of you are using NetBarrierX, it seems more and more likely that NetBarrierX is causing the problem. I know that you (darkpaw) said you disabled the kernerl extension for NetBarrierX but maybe some other part of it is still active. I would recommend uninstalling it completely as a test. But a more inofrmative route would be to run one of the low-level network tools as I recommended earlier and see exactly what is happening with your HTTP requests. That should tell us very quickly whether it is NetBarrier related or not. To do this, first start a tcpdump or tcpflow session in a Terminal window. I prefer tcpflow (available via fink) - it is easier to interpret the results. You would run tcpflow with the following command: sudo tcpflow -i en0 -c > my_output where the ">" acts to capture the output from tcpflow into a file (my_output) and where the "en0" is what you would use for an Ethernet connection - for Airport, use "en1". Then use your web browser as usual and click on the link. Finally, stop the tcpflow in Terminal by holding down Ctrl and pressing the C key (i.e. control-C) and look at the file with any text editor. Copy & paste the contents of the file here so we can analyze it.

08-10-2003, 08:50 PM	#14
darkpaw All Star Join Date: Apr 2002 Location: England Posts: 513	Then why doesn't it work when I uninstall NetBarrier??? Maybe yours is fixed, but what about mine? __________________ http://www.keeponfighting.net - Fighting for animal rights http://www.darkpaw.co.uk http://www.needstuff.co.uk - Recycle your unwanted clutter for FREE! (UK only)

08-10-2003, 08:57 PM	#15
houchin Major Leaguer Join Date: Jan 2002 Location: Northern Virginai Posts: 294	My only thought was that uninstalling NetBarrier just uninstalled the app, but was not perfect about deinstalling the firewall and filtering rules, especially since NBX is really just a front end to ipfw. I suggest reinstalling NBX and just turning off the filtering.

08-11-2003, 02:58 PM	#17
darkpaw All Star Join Date: Apr 2002 Location: England Posts: 513	Fixed!!! Fixed Yes, it was NBX. There is one little banner filter ad thing in there, thus: URL Path contains ad.cgi Guess what download.cgi contains too... Well, it didn't explain why I uninstalled and still had the problem (the filter can't have been working), but I tried again, uninstalled, rebooted, reinstalled, works now. Fix, re-enable the banner filter, just remove that one condition noted above. __________________ http://www.keeponfighting.net - Fighting for animal rights http://www.darkpaw.co.uk http://www.needstuff.co.uk - Recycle your unwanted clutter for FREE! (UK only)

10-23-2007, 12:38 AM	#18
Spiral Girl Triple-A Player Join Date: Dec 2006 Posts: 151	houchin, Thanks, eric2006 directed me to this link as I had the same problem with the GIF image. The Privacy, switching banner to off worked for me too. S.