Simple Rust Reverse Proxy

gistfile1.rs

extern crate hyper;
extern crate url;
 
static HOST: &'static str = "www.google.com";
 
macro_rules! ret_err(
	($e:expr) => {{
		match $e {
			Ok(v) => v,
			Err(e) => { println!("Line {}: {}", line!(), e); return; }
		}
	}}
);
 
/// Given a `hyper::uri::RequestUri`, rewrite it to a `Url` substituting `HOST`
/// for the domain.
fn create_proxy_url(uri: hyper::uri::RequestUri, host: &str) -> Result<url::Url, url::ParseError> {
	use hyper::uri::RequestUri::*;
	match uri {
		AbsolutePath(val) => url::Url::parse(&format!("http://{}{}", host, val)),
		AbsoluteUri(_) => Err(url::ParseError::InvalidScheme), //todo: rewrite uri
		_ => Err(url::ParseError::InvalidScheme)
	}
}
 
//todo move mut to the type
fn proxy_request(mut request: hyper::server::Request, host: &str) -> Result<hyper::client::Response, hyper::Error> {
	use hyper::header::Host;
 
	let mut client = hyper::Client::new();
 
	// Read in the request body.
	let mut request_body: Vec<u8> = Vec::new();
	try!(::std::io::copy(&mut request, &mut request_body));
 
	// The host header must be changed for compatibility with v-hosts.
	let mut headers = request.headers;
	headers.set(Host {
		hostname: host.to_string(),
		port: None
	});
 
	// Rewrite the target url from the client's request.
	let url = try!(create_proxy_url(request.uri, host));
 
	// Build and send the proxy's request.
	let proxy_response = try!(
		client.request(request.method, url)
		.headers(headers)
		.body(&request_body[..])
		.send());
 
	return Ok(proxy_response);
}
 
fn handler(request: hyper::server::Request, mut response: hyper::server::Response<hyper::net::Fresh>) -> () {
	let mut proxy_response = ret_err!(proxy_request(request, HOST));
 
	// Copy the proxy's response headers verbatim into the server's response
	// headers.
	*response.status_mut() = proxy_response.status.clone();
	*response.headers_mut() = proxy_response.headers.clone();
 
	// Write the headers and rewrite the proxy's response body to the client.
	let mut response = ret_err!(response.start());
	ret_err!(::std::io::copy(&mut proxy_response, &mut response));
	ret_err!(response.end());
}
 
fn main() {
	let server = hyper::Server::http(handler);
	ret_err!(server.listen("127.0.0.1:3000"));
}