C web proxy not showing images

[minhaferzz]

I programmed a web proxy in C and the pages seem to load fine. The only problem is images don't load up. I see all the requests for the images and see the data transmitted. When the messages are written to the browser, they don't show up. Anyone have an idea why this would be? What I'm confused on is do images have to be handled differently than the regular html text?

I'm reading everything from the web server(eg Google) into a char buffer of 2048 and write to the browser. This loops until there is nothing more to read. Like I said, the webproxy shows that there is information transferred, but I just get the red x.

[anog]

Is the proxy sending the HTTP headers correctly?

While browsers usually display HTML pages properly if the headers aren't there, they can't display images if the headers aren't there...

I learnt this while I was creating a small webserver. Browsers only started displaying images when I implented the "sendheaders" function. HTML on the other hand was always displayed properly, even without headers.

[minhaferzz]

  anog said:

Is the proxy sending the HTTP headers correctly?

While browsers usually display HTML pages properly if the headers aren't there, they can't display images if the headers aren't there...

I learnt this while I was creating a small webserver. Browsers only started displaying images when I implented the "sendheaders" function. HTML on the other hand was always displayed properly, even without headers.

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So I need to forward the entire request, including headers? I figured that just the GET request with the file and protocol was enough. I didn't think that I needed to include the entire header. Let me give this a try. Thanks for the explaination.

[minhaferzz]

Still no luck getting the image to load. I just don't see how I can transfer the image data correctly with a character buffer. Does anyone have an idea how I can handle this data correctly? The information that is being passed to the browser is the same information when you open an image in notepad, garbled text and symbols. Any suggestions?

[GAM]

  minhaferzz said:

Still no luck getting the image to load.  I just don't see how I can transfer the image data correctly with a character buffer.  Does anyone have an idea how I can handle this data correctly?  The information that is being passed to the browser is the same information when you open an image in notepad, garbled text and symbols.  Any suggestions?

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Be careful with your buffer, because it contains binary data if you use it for transferring images. Thus a string function like strlen() for example will likely not work --at least not all the time. You may want to consider an array of bytes instead.

The easy way to resolve your problem is to sniff on the network traffic with and without your proxy and then compare the results for the same requests, then you should be able to tell what is different when the proxy is enabled and it should be trivial to fix.

[minhaferzz]

I don't think C/C++ has a byte data type, or does it? I know Java and C# do, and I've been trying to find this out to no avail.

[azcodemonkey]

C# does have a byte data type.

[benjeeeboy]

  minhaferzz said:

I don't think C/C++ has a byte data type, or does it?  I know Java and C# do, and I've been trying to find this out to no avail.

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char is a 1 byte integer type

[anog]

How are you transferring the data from the proxy to the client?

In my webserver I'm reading one char at a time from the file, and sending it to the connected socket, and never had problems.