I'm developing an LSP and I need to know what exact URL is.
For example, let's say user is using Firefox to browse pages. I want to get the page full URL whether it is HTTP or HTTPS. How can I do this?
I can get address by fetching the HTTP request header (Request Line and Host); however the protocol (http,https) cannot be figured out this way.
An LSP resides in the TCP/IP protocol stack. If port numbers, eg 443 for SSL, are not reliable for your purpose, you will have to examine the TCP payload to figure out if the packet uses SSL or TLS. You will have to keep state and if you can see SSL/TLS handshake messages then you'd know it is an HTTPS connection attempt.
There is a very basic description of the handshake SSL/TLS in Detail on MSDN.