layer4-proxy/src/servers/protocol/tcp.rs
2021-11-01 15:25:12 +08:00

131 lines
4.1 KiB
Rust

use crate::config::Upstream;
use crate::servers::protocol::tls::get_sni;
use crate::servers::Proxy;
use futures::future::try_join;
use log::{debug, error, warn};
use std::sync::Arc;
use tokio::io;
use tokio::io::{AsyncRead, AsyncWrite, AsyncWriteExt};
use tokio::net::{TcpListener, TcpStream};
pub async fn proxy(config: Arc<Proxy>) -> Result<(), Box<dyn std::error::Error>> {
let listener = TcpListener::bind(config.listen).await?;
let config = config.clone();
loop {
let thread_proxy = config.clone();
match listener.accept().await {
Err(err) => {
error!("Failed to accept connection: {}", err);
return Err(Box::new(err));
}
Ok((stream, _)) => {
tokio::spawn(async move {
match accept(stream, thread_proxy).await {
Ok(_) => {}
Err(err) => {
error!("Relay thread returned an error: {}", err);
}
};
});
}
}
}
}
async fn accept(inbound: TcpStream, proxy: Arc<Proxy>) -> Result<(), Box<dyn std::error::Error>> {
debug!("New connection from {:?}", inbound.peer_addr()?);
let upstream_name = match proxy.tls {
false => proxy.default.clone(),
true => {
let mut hello_buf = [0u8; 1024];
inbound.peek(&mut hello_buf).await?;
let snis = get_sni(&hello_buf);
if snis.is_empty() {
proxy.default.clone()
} else {
match proxy.sni.clone() {
Some(sni_map) => {
let mut upstream = proxy.default.clone();
for sni in snis {
let m = sni_map.get(&sni);
if m.is_some() {
upstream = m.unwrap().clone();
break;
}
}
upstream
}
None => proxy.default.clone(),
}
}
}
};
debug!("Upstream: {}", upstream_name);
let upstream = match proxy.upstream.get(&upstream_name) {
Some(upstream) => upstream,
None => {
warn!(
"No upstream named {:?} on server {:?}",
proxy.default, proxy.name
);
return process(inbound, proxy.upstream.get(&proxy.default).unwrap()).await;
// ToDo: Remove unwrap and check default option
}
};
return process(inbound, upstream).await;
}
async fn process(
mut inbound: TcpStream,
upstream: &Upstream,
) -> Result<(), Box<dyn std::error::Error>> {
match upstream {
Upstream::Ban => {
let _ = inbound.shutdown();
}
Upstream::Echo => {
let (mut ri, mut wi) = io::split(inbound);
let inbound_to_inbound = copy(&mut ri, &mut wi);
let bytes_tx = inbound_to_inbound.await;
debug!("Bytes read: {:?}", bytes_tx);
}
Upstream::Custom(custom) => {
match custom.protocol.as_ref() {
"tcp" => {
let outbound = TcpStream::connect(custom.addr.clone()).await?;
let (mut ri, mut wi) = io::split(inbound);
let (mut ro, mut wo) = io::split(outbound);
let inbound_to_outbound = copy(&mut ri, &mut wo);
let outbound_to_inbound = copy(&mut ro, &mut wi);
let (bytes_tx, bytes_rx) = try_join(inbound_to_outbound, outbound_to_inbound).await?;
debug!("Bytes read: {:?} write: {:?}", bytes_tx, bytes_rx);
}
_ => {}
}
}
};
Ok(())
}
async fn copy<'a, R, W>(reader: &'a mut R, writer: &'a mut W) -> io::Result<u64>
where
R: AsyncRead + Unpin + ?Sized,
W: AsyncWrite + Unpin + ?Sized,
{
match io::copy(reader, writer).await {
Ok(u64) => {
let _ = writer.shutdown().await;
Ok(u64)
}
Err(_) => Ok(0),
}
}