ptth/prototypes/quic_demo/src/bin/quic_demo_relay_server.rs

use quic_demo::prelude::*;

#[tokio::main]
async fn main () -> anyhow::Result <()> {
	tracing_subscriber::fmt::init ();
	
	let server_addr = "0.0.0.0:30380".parse ()?;
	let (mut incoming, server_cert) = make_server_endpoint (server_addr)?;
	tokio::fs::write ("quic_server.crt", &server_cert).await?;
	
	debug! ("Waiting for end server to connect");
	
	let end_server_conn = incoming.next ().await.ok_or_else (|| anyhow::anyhow! ("No end server connection"))?;
	
	let end_server_conn = end_server_conn.await?;
	
	let quinn::NewConnection {
		connection: end_server_conn,
		..
	} = end_server_conn;
	
	debug! ("Waiting for client to connect");
	
	let client_conn = incoming.next ().await.ok_or_else (|| anyhow::anyhow! ("No client connection"))?;
	
	let client_conn = client_conn.await?;
	
	let quinn::NewConnection {
		connection: _client_conn,
		bi_streams: mut client_incoming_bi_streams,
		..
	} = client_conn;
	
	debug! ("Waiting for client to open bi stream");
	
	let (mut client_send, mut client_recv) = client_incoming_bi_streams.next ().await.ok_or_else (|| anyhow::anyhow! ("Client didn't open a bi stream"))??;
	
	debug! ("Opening bi stream to the end server");
	
	let (mut server_send, mut server_recv) = end_server_conn.open_bi ().await?;
	
	debug! ("Relaying bytes...");
	
	// Remember to swap tx and rx for patch cables
	
	let uplink_task = tokio::spawn (async move {
		// Uplink - Client to end server
		
		let mut buf = vec! [0u8; 65_536];
		while let Some (bytes_read) = client_recv.read (&mut buf).await? {
			let buf_slice = &buf [0..bytes_read];
			server_send.write_all (buf_slice).await?;
		}
		
		debug! ("Uplink closed");
		
		Ok::<_, anyhow::Error> (())
	});
	
	let downlink_task = tokio::spawn (async move {
		// Downlink - End server to client
		
		let mut buf = vec! [0u8; 65_536];
		while let Some (bytes_read) = server_recv.read (&mut buf).await? {
			let buf_slice = &buf [0..bytes_read];
			client_send.write_all (buf_slice).await?;
		}
		
		debug! ("Downlink closed");
		
		Ok::<_, anyhow::Error> (())
	});
	
	uplink_task.await??;
	downlink_task.await??;
	
	Ok (())
}