How to pass data from underlying transport layer to hyper service?

[jobenye]

Some data in transport layer is useful for upper layer. For example, I'd like to check SNI in ClientHello against Host in HTTP Request, also need to take out some info from client cert for further processing.

But looks like the function service_fn() only accept one argument with type hyper::Request. Anyone knows how to overcome the difficulty? Appreciated if there were any sample/pseudo code ..

pub fn service_fn<F, R, S>(f: F) -> ServiceFn<F, R> 
where
    F: FnMut(Request<R>) -> S,
    S: Future,