On Oct 10, 10:55 am, "Skybuck Flying" <s...@hotmail.com> wrote:
> <snip>
>
> > My other question I still have problems because I was thinking that on
> > the application layer for example only HTTP data are received. The IP
> > and port and the transport kind (TCP/UDP/ICMP) are removed. But there
> > must be still a problem in my logic.
>
> You are correct, applications which use the winsock api (which is an api to
> work with/access the tcp/ip stack) usually removes ip/tcp/udp headers and
> that sort of thing and only returns http protocol headers/content.
>

That's not 100% correct. The socket API (winsock etc) only removes
data from the IP and TCP headers from the data stream. Most of that
information is still available to the application using other
functions in the sockets API. Think of the socket API as a convenient
unwrapper which stuffs things it understands into structs you can
query and dumps things it doesn't understand (it's payload) to recv()
to be handled by the application.