use std::net::IpAddr;
use std::sync::Arc;
use std::sync::atomic::{AtomicBool, Ordering};
use std::time::Duration;
use base64::Engine;
use base64::engine::general_purpose::STANDARD;
use tokio::io::{AsyncRead, AsyncReadExt, AsyncWrite, AsyncWriteExt};
use tokio::sync::mpsc;
use tokio::task::JoinSet;
use tokio::time::{MissedTickBehavior, interval, timeout};
use zeroize::Zeroizing;
use crate::error::{Error, Result};
use crate::frame::{Frame, FrameType};
use crate::handshake::{ClientHandshake, accept_client};
use crate::identity::Identity;
use crate::mux::{MuxHandle, MuxStream};
use crate::outbound::{connect_tcp, connect_udp};
use crate::protection::{ProtectionMode, SESSION_KEY_LEN, Side, StreamProtector};
use crate::wire_io::{read_frame, write_frame};
const RELAY_BUFFER: usize = 16 * 1024;
const CONNECT_TIMEOUT: Duration = Duration::from_secs(15);
#[derive(Clone)]
pub struct ClientSession {
mux: MuxHandle,
master: Arc
>,
mode: ProtectionMode,
}
#[derive(Clone, Debug, Eq, PartialEq, Hash)]
pub struct Target {
pub host: TargetHost,
pub port: u16,
}
#[derive(Clone, Debug, Eq, PartialEq, Hash)]
pub enum TargetHost {
Ip(IpAddr),
Domain(String),
}
pub struct ProtectedStream {
stream: MuxStream,
protector: StreamProtector,
}
pub struct ServerEstablished {
pub master: Zeroizing<[u8; SESSION_KEY_LEN]>,
pub identity: [u8; 32],
}
enum OpenRequest {
Control,
Tcp(Target),
Udp(Target),
}
impl Target {
pub fn new(host: TargetHost, port: u16) -> Result {
if port == 0 {
return Err(Error::Protocol("target port cannot be zero".to_owned()));
}
if let TargetHost::Domain(domain) = &host {
validate_domain(domain)?;
}
Ok(Self { host, port })
}
pub fn domain(domain: impl Into, port: u16) -> Result {
Self::new(TargetHost::Domain(domain.into()), port)
}
pub fn ip(ip: IpAddr, port: u16) -> Result {
Self::new(TargetHost::Ip(ip), port)
}
pub fn domain_name(&self) -> Option<&str> {
match &self.host {
TargetHost::Domain(domain) => Some(domain),
TargetHost::Ip(_) => None,
}
}
pub fn ip_address(&self) -> Option {
match self.host {
TargetHost::Ip(ip) => Some(ip),
TargetHost::Domain(_) => None,
}
}
}
impl ClientSession {
pub fn new(
mux: MuxHandle,
master: Zeroizing<[u8; SESSION_KEY_LEN]>,
mode: ProtectionMode,
) -> Self {
Self {
mux,
master: Arc::new(master),
mode,
}
}
pub async fn open_tcp(&self, target: &Target) -> Result {
let request = encode_open(&OpenRequest::Tcp(target.clone()))?;
self.open(request).await
}
pub async fn open_udp(&self, target: &Target) -> Result {
let request = encode_open(&OpenRequest::Udp(target.clone()))?;
self.open(request).await
}
async fn open_control(&self) -> Result {
self.open(encode_open(&OpenRequest::Control)?).await
}
async fn open(&self, request: Vec) -> Result {
let mut stream = self.mux.open().await?;
let mut protector = StreamProtector::new(&self.master, stream.id, Side::Client, self.mode)?;
let frame = protector.seal(FrameType::Open, 0, &request)?;
write_frame(&mut stream.io, &frame, self.mode.tag_len()).await?;
let response = read_frame(&mut stream.io, self.mode.tag_len()).await?;
let kind = response.kind;
let payload = protector.open(response)?;
match kind {
FrameType::OpenOk if payload.is_empty() => Ok(ProtectedStream { stream, protector }),
FrameType::Error => Err(Error::Carrier(
"remote endpoint rejected the stream".to_owned(),
)),
_ => Err(Error::Protocol(
"unexpected stream-open response".to_owned(),
)),
}
}
pub async fn monitor_heartbeat(&self, period: Duration) -> Result<()> {
if period.is_zero() {
return Err(Error::Config("heartbeat cannot be zero".to_owned()));
}
let mut control = self.open_control().await?;
let mut ticker = interval(period);
ticker.set_missed_tick_behavior(MissedTickBehavior::Delay);
ticker.tick().await;
loop {
ticker.tick().await;
let frame = control.protector.seal(FrameType::Heartbeat, 0, &[])?;
write_frame(&mut control.stream.io, &frame, self.mode.tag_len()).await?;
let response = timeout(
period,
read_frame(&mut control.stream.io, self.mode.tag_len()),
)
.await
.map_err(|_| Error::Carrier("heartbeat timed out".to_owned()))??;
let kind = response.kind;
let payload = control.protector.open(response)?;
if kind != FrameType::Heartbeat || !payload.is_empty() {
return Err(Error::Protocol("invalid heartbeat response".to_owned()));
}
}
}
pub async fn abort(&self) {
self.mux.abort().await;
}
pub async fn wait_closed(&self) {
self.mux.wait_closed().await;
}
}
impl ProtectedStream {
pub async fn send(&mut self, payload: &[u8]) -> Result<()> {
let frame = self.protector.seal(FrameType::Data, 0, payload)?;
write_frame(&mut self.stream.io, &frame, self.protector.tag_len()).await
}
/// Reads the next application payload from the stream. Used by the UDP
/// relay paths, where each `Data` frame carries exactly one datagram
/// rather than an arbitrary byte-stream chunk. `Ok(None)` means the
/// remote side closed the stream cleanly.
pub async fn recv(&mut self) -> Result>> {
let tag_len = self.protector.tag_len();
let frame = read_frame(&mut self.stream.io, tag_len).await?;
let kind = frame.kind;
let payload = self.protector.open(frame)?;
match kind {
FrameType::Data => Ok(Some(payload)),
FrameType::Close if payload.is_empty() => Ok(None),
FrameType::Error => Err(Error::Carrier("remote stream failed".to_owned())),
_ => Err(Error::Protocol("unexpected relay frame".to_owned())),
}
}
/// Signals a clean end of the datagram stream to the remote side.
pub async fn close(&mut self) -> Result<()> {
let frame = self.protector.seal(FrameType::Close, 0, &[])?;
write_frame(&mut self.stream.io, &frame, self.protector.tag_len()).await
}
pub async fn relay(mut self, local: L) -> Result<()>
where
L: AsyncRead + AsyncWrite + Unpin,
{
let tag_len = self.protector.tag_len();
let (mut local_reader, mut local_writer) = tokio::io::split(local);
let (mut tunnel_reader, mut tunnel_writer) = tokio::io::split(self.stream.io);
let mut local_open = true;
let mut remote_open = true;
let mut buffer = vec![0_u8; RELAY_BUFFER];
while local_open || remote_open {
enum Event {
Local(std::io::Result),
Remote(Result),
}
let event = tokio::select! {
read = local_reader.read(&mut buffer), if local_open => Event::Local(read),
frame = read_frame(&mut tunnel_reader, tag_len), if remote_open => {
Event::Remote(frame)
}
};
match event {
Event::Local(Ok(0)) => {
let close = self.protector.seal(FrameType::Close, 0, &[])?;
write_frame(&mut tunnel_writer, &close, tag_len).await?;
tunnel_writer.shutdown().await?;
local_open = false;
}
Event::Local(Ok(length)) => {
let data = self.protector.seal(FrameType::Data, 0, &buffer[..length])?;
write_frame(&mut tunnel_writer, &data, tag_len).await?;
}
Event::Local(Err(error)) => return Err(error.into()),
Event::Remote(Ok(frame)) => {
let kind = frame.kind;
let payload = self.protector.open(frame)?;
match kind {
FrameType::Data => local_writer.write_all(&payload).await?,
FrameType::Close if payload.is_empty() => {
local_writer.shutdown().await?;
remote_open = false;
}
FrameType::Error => {
return Err(Error::Carrier("remote stream failed".to_owned()));
}
_ => return Err(Error::Protocol("unexpected relay frame".to_owned())),
}
}
Event::Remote(Err(error)) => return Err(error),
}
}
Ok(())
}
}
pub async fn client_handshake(
stream: &mut S,
identity: &Identity,
mode: ProtectionMode,
) -> Result>
where
S: AsyncRead + AsyncWrite + Unpin,
{
let (handshake, hello) = ClientHandshake::start(identity, mode)?;
write_frame(stream, &plain_frame(FrameType::ClientHello, hello), 0).await?;
let response = read_frame(stream, 0).await?;
validate_plain_handshake(&response, FrameType::ServerHello)?;
let established = handshake.complete(&response.payload)?;
write_frame(
stream,
&plain_frame(FrameType::ClientFinish, established.finish.to_vec()),
0,
)
.await?;
Ok(established.master)
}
pub async fn server_handshake(
stream: &mut S,
mode: ProtectionMode,
allowed: &[[u8; 32]],
) -> Result
where
S: AsyncRead + AsyncWrite + Unpin,
{
let hello = read_client_hello(stream).await?;
server_handshake_with_hello(stream, hello, mode, allowed).await
}
/// Reads a raw, unauthenticated `ClientHello` frame off the wire.
///
/// This is split out from [`server_handshake`] so callers can inspect the
/// client's identity (see [`crate::handshake::peek_client_identity`]) before
/// deciding whether to run the full handshake or a fallback response for an
/// unrecognized client.
pub async fn read_client_hello(stream: &mut S) -> Result
where
S: AsyncRead + Unpin,
{
let hello = read_frame(stream, 0).await?;
validate_plain_handshake(&hello, FrameType::ClientHello)?;
Ok(hello)
}
pub async fn server_handshake_with_hello(
stream: &mut S,
hello: Frame,
mode: ProtectionMode,
allowed: &[[u8; 32]],
) -> Result
where
S: AsyncRead + AsyncWrite + Unpin,
{
let (response, pending) = accept_client(&hello.payload, mode, allowed)?;
let identity = pending.identity();
write_frame(stream, &plain_frame(FrameType::ServerHello, response), 0).await?;
let finish = read_frame(stream, 0).await?;
validate_plain_handshake(&finish, FrameType::ClientFinish)?;
Ok(ServerEstablished {
master: pending.finish(&finish.payload)?,
identity,
})
}
/// Re-encodes a previously decoded, unprotected frame back into wire bytes.
/// Used to forward the exact bytes of an unrecognized client's hello to a
/// fallback backend.
pub fn encode_plain_frame(frame: &Frame) -> Result> {
frame.encode(0)
}
pub fn decode_public_keys(values: impl IntoIterator- ) -> Result> {
values
.into_iter()
.map(|value| {
let bytes = STANDARD
.decode(value)
.map_err(|_| Error::Config("client public key is not base64".to_owned()))?;
bytes
.try_into()
.map_err(|_| Error::Config("client public key must contain 32 bytes".to_owned()))
})
.collect()
}
pub async fn serve_session(
mut incoming: mpsc::Receiver,
mux: MuxHandle,
master: Zeroizing<[u8; SESSION_KEY_LEN]>,
mode: ProtectionMode,
heartbeat: Duration,
) -> Result<()> {
let master = Arc::new(master);
let control_active = Arc::new(AtomicBool::new(false));
let mut streams = JoinSet::new();
loop {
tokio::select! {
incoming_stream = incoming.recv() => match incoming_stream {
Some(stream) => {
let master = master.clone();
let mux = mux.clone();
let control_active = control_active.clone();
streams.spawn(async move {
serve_stream(stream, master, mode, heartbeat, mux, control_active).await
});
}
None => break,
},
result = streams.join_next(), if !streams.is_empty() => {
if let Some(Err(error)) = result {
return Err(Error::Runtime(format!("server stream task failed: {error}")));
}
}
() = mux.wait_closed() => break,
}
}
streams.abort_all();
Ok(())
}
async fn serve_stream(
mut stream: MuxStream,
master: Arc>,
mode: ProtectionMode,
heartbeat: Duration,
mux: MuxHandle,
control_active: Arc,
) -> Result<()> {
let mut protector = StreamProtector::new(&master, stream.id, Side::Server, mode)?;
let open = timeout(heartbeat, read_frame(&mut stream.io, mode.tag_len()))
.await
.map_err(|_| Error::Protocol("stream open timed out".to_owned()))??;
let kind = open.kind;
let payload = protector.open(open)?;
if kind != FrameType::Open {
return Err(Error::Protocol(
"stream does not start with open".to_owned(),
));
}
match decode_open(&payload)? {
OpenRequest::Control => {
if control_active.swap(true, Ordering::AcqRel) {
send_open_error(&mut stream, &mut protector, mode).await?;
return Err(Error::Protocol("duplicate control stream".to_owned()));
}
send_open_ok(&mut stream, &mut protector, mode).await?;
let result = serve_control(stream, protector, mode, heartbeat).await;
control_active.store(false, Ordering::Release);
if result.is_err() {
mux.abort().await;
}
result
}
OpenRequest::Tcp(target) => {
let remote = match timeout(CONNECT_TIMEOUT, connect_target(&target)).await {
Ok(Ok(remote)) => remote,
Ok(Err(error)) => {
send_open_error(&mut stream, &mut protector, mode).await?;
return Err(error);
}
Err(_) => {
send_open_error(&mut stream, &mut protector, mode).await?;
return Err(Error::Carrier("target connection timed out".to_owned()));
}
};
send_open_ok(&mut stream, &mut protector, mode).await?;
ProtectedStream { stream, protector }.relay(remote).await
}
OpenRequest::Udp(target) => {
let socket = match timeout(CONNECT_TIMEOUT, connect_udp(&target)).await {
Ok(Ok(socket)) => socket,
Ok(Err(error)) => {
send_open_error(&mut stream, &mut protector, mode).await?;
return Err(error);
}
Err(_) => {
send_open_error(&mut stream, &mut protector, mode).await?;
return Err(Error::Carrier("target connection timed out".to_owned()));
}
};
send_open_ok(&mut stream, &mut protector, mode).await?;
relay_udp(ProtectedStream { stream, protector }, socket).await
}
}
}
/// Datagram size ceiling for a single relayed UDP payload (the maximum
/// theoretical UDP payload over IPv4/IPv6).
const MAX_UDP_DATAGRAM: usize = 65_507;
/// Pumps datagrams between a connected local UDP socket and a `Udp`
/// tunnel stream, one `Data` frame per datagram in each direction.
async fn relay_udp(mut stream: ProtectedStream, socket: tokio::net::UdpSocket) -> Result<()> {
let mut buffer = vec![0_u8; MAX_UDP_DATAGRAM];
loop {
tokio::select! {
received = socket.recv(&mut buffer) => {
let length = received?;
stream.send(&buffer[..length]).await?;
}
frame = stream.recv() => {
match frame? {
Some(payload) => {
socket.send(&payload).await?;
}
None => return Ok(()),
}
}
}
}
}
async fn serve_control(
mut stream: MuxStream,
mut protector: StreamProtector,
mode: ProtectionMode,
heartbeat: Duration,
) -> Result<()> {
let deadline = heartbeat
.checked_mul(2)
.ok_or_else(|| Error::Config("heartbeat duration overflow".to_owned()))?;
loop {
let frame = timeout(deadline, read_frame(&mut stream.io, mode.tag_len()))
.await
.map_err(|_| Error::Carrier("client heartbeat timed out".to_owned()))??;
let kind = frame.kind;
let payload = protector.open(frame)?;
if kind != FrameType::Heartbeat || !payload.is_empty() {
return Err(Error::Protocol("invalid control frame".to_owned()));
}
let response = protector.seal(FrameType::Heartbeat, 0, &[])?;
write_frame(&mut stream.io, &response, mode.tag_len()).await?;
}
}
async fn send_open_ok(
stream: &mut MuxStream,
protector: &mut StreamProtector,
mode: ProtectionMode,
) -> Result<()> {
let response = protector.seal(FrameType::OpenOk, 0, &[])?;
write_frame(&mut stream.io, &response, mode.tag_len()).await
}
async fn send_open_error(
stream: &mut MuxStream,
protector: &mut StreamProtector,
mode: ProtectionMode,
) -> Result<()> {
let response = protector.seal(FrameType::Error, 0, &[1])?;
write_frame(&mut stream.io, &response, mode.tag_len()).await
}
async fn connect_target(target: &Target) -> Result {
match &target.host {
TargetHost::Ip(ip) => connect_tcp(std::net::SocketAddr::new(*ip, target.port)).await,
TargetHost::Domain(domain) => connect_tcp((domain.as_str(), target.port)).await,
}
}
fn plain_frame(kind: FrameType, payload: Vec) -> Frame {
Frame {
kind,
flags: 0,
sequence: 0,
payload,
tag: Vec::new(),
}
}
fn validate_plain_handshake(frame: &Frame, expected: FrameType) -> Result<()> {
if frame.kind != expected || frame.flags != 0 || frame.sequence != 0 || !frame.tag.is_empty() {
return Err(Error::Protocol("invalid handshake frame".to_owned()));
}
Ok(())
}
fn encode_open(request: &OpenRequest) -> Result> {
match request {
OpenRequest::Control => Ok(vec![0]),
OpenRequest::Tcp(target) => encode_target(1, target),
OpenRequest::Udp(target) => encode_target(2, target),
}
}
fn encode_target(protocol: u8, target: &Target) -> Result> {
let mut output = vec![protocol];
match &target.host {
TargetHost::Ip(IpAddr::V4(ip)) => {
output.push(1);
output.extend_from_slice(&ip.octets());
}
TargetHost::Ip(IpAddr::V6(ip)) => {
output.push(2);
output.extend_from_slice(&ip.octets());
}
TargetHost::Domain(domain) => {
validate_domain(domain)?;
let length = u8::try_from(domain.len())
.map_err(|_| Error::Protocol("target domain is too long".to_owned()))?;
output.push(3);
output.push(length);
output.extend_from_slice(domain.as_bytes());
}
}
output.extend_from_slice(&target.port.to_be_bytes());
Ok(output)
}
fn decode_open(input: &[u8]) -> Result {
let Some(protocol) = input.first().copied() else {
return Err(Error::Protocol("empty stream-open request".to_owned()));
};
if protocol == 0 {
if input.len() != 1 {
return Err(Error::Protocol("invalid control-open request".to_owned()));
}
return Ok(OpenRequest::Control);
}
if protocol != 1 && protocol != 2 {
return Err(Error::Protocol("unknown stream protocol".to_owned()));
}
if input.len() < 4 {
return Err(Error::Protocol("truncated stream-open request".to_owned()));
}
let (host, offset) = match input[1] {
1 if input.len() >= 8 => (
TargetHost::Ip(IpAddr::from(
<[u8; 4]>::try_from(&input[2..6]).expect("IPv4 length"),
)),
6,
),
2 if input.len() >= 20 => (
TargetHost::Ip(IpAddr::from(
<[u8; 16]>::try_from(&input[2..18]).expect("IPv6 length"),
)),
18,
),
3 => {
let length = input[2] as usize;
let end = 3_usize
.checked_add(length)
.ok_or_else(|| Error::Protocol("target domain length overflow".to_owned()))?;
if input.len() < end + 2 {
return Err(Error::Protocol("truncated target domain".to_owned()));
}
let domain = std::str::from_utf8(&input[3..end])
.map_err(|_| Error::Protocol("target domain is not UTF-8".to_owned()))?
.to_owned();
(TargetHost::Domain(domain), end)
}
_ => return Err(Error::Protocol("invalid target address type".to_owned())),
};
if input.len() != offset + 2 {
return Err(Error::Protocol("stream-open length mismatch".to_owned()));
}
let port = u16::from_be_bytes(
input[offset..]
.try_into()
.map_err(|_| Error::Protocol("invalid target port".to_owned()))?,
);
let target = Target::new(host, port)?;
if protocol == 1 {
Ok(OpenRequest::Tcp(target))
} else {
Ok(OpenRequest::Udp(target))
}
}
fn validate_domain(domain: &str) -> Result<()> {
let domain = domain.strip_suffix('.').unwrap_or(domain);
if domain.is_empty() || domain.len() > 253 {
return Err(Error::Protocol("invalid target domain".to_owned()));
}
for label in domain.split('.') {
if label.is_empty()
|| label.len() > 63
|| label.starts_with('-')
|| label.ends_with('-')
|| !label
.bytes()
.all(|byte| byte.is_ascii_alphanumeric() || byte == b'-')
{
return Err(Error::Protocol("invalid target domain".to_owned()));
}
}
Ok(())
}
#[cfg(test)]
mod tests {
use tokio::io::{AsyncReadExt, AsyncWriteExt};
use yamux::Mode;
use super::*;
use crate::mux;
#[test]
fn target_codec_round_trips_ipv4_ipv6_and_domains() {
let targets = [
Target::ip("127.0.0.1".parse().unwrap(), 80).unwrap(),
Target::ip("::1".parse().unwrap(), 443).unwrap(),
Target::domain("example.com", 53).unwrap(),
];
for target in targets {
let encoded = encode_open(&OpenRequest::Tcp(target.clone())).unwrap();
let OpenRequest::Tcp(decoded) = decode_open(&encoded).unwrap() else {
panic!("decoded wrong protocol");
};
assert_eq!(decoded, target);
}
}
#[tokio::test]
async fn handshake_then_protected_yamux_stream_reaches_a_real_tcp_target() {
let destination = tokio::net::TcpListener::bind("127.0.0.1:0").await.unwrap();
let destination_address = destination.local_addr().unwrap();
let echo = tokio::spawn(async move {
let (mut stream, _) = destination.accept().await.unwrap();
let mut data = [0_u8; 4];
stream.read_exact(&mut data).await.unwrap();
stream.write_all(&data).await.unwrap();
});
let identity = Identity::generate().unwrap();
let public = identity.public();
let (mut client_io, mut server_io) = tokio::io::duplex(128 * 1024);
let server_handshake_task = tokio::spawn(async move {
server_handshake(&mut server_io, ProtectionMode::ChaChaPoly, &[public])
.await
.map(|established| (server_io, established))
});
let client_master = client_handshake(&mut client_io, &identity, ProtectionMode::ChaChaPoly)
.await
.unwrap();
let (server_io, server) = server_handshake_task.await.unwrap().unwrap();
let window = 8 * yamux::DEFAULT_CREDIT as usize;
let (client_mux, _) = mux::spawn(client_io, Mode::Client, 8, window).unwrap();
let (server_mux, incoming) = mux::spawn(server_io, Mode::Server, 8, window).unwrap();
let server_session = tokio::spawn(serve_session(
incoming,
server_mux,
server.master,
ProtectionMode::ChaChaPoly,
Duration::from_secs(2),
));
let client = ClientSession::new(client_mux, client_master, ProtectionMode::ChaChaPoly);
let protected = client
.open_tcp(&Target::ip(destination_address.ip(), destination_address.port()).unwrap())
.await
.unwrap();
let (mut application, relay_side) = tokio::io::duplex(1024);
let relay = tokio::spawn(protected.relay(relay_side));
application.write_all(b"ping").await.unwrap();
let mut response = [0_u8; 4];
application.read_exact(&mut response).await.unwrap();
assert_eq!(&response, b"ping");
drop(application);
relay.await.unwrap().unwrap();
client.abort().await;
server_session.await.unwrap().unwrap();
echo.await.unwrap();
}
#[test]
fn udp_target_codec_round_trips() {
let target = Target::ip("203.0.113.9".parse().unwrap(), 5353).unwrap();
let encoded = encode_open(&OpenRequest::Udp(target.clone())).unwrap();
let OpenRequest::Udp(decoded) = decode_open(&encoded).unwrap() else {
panic!("decoded wrong protocol");
};
assert_eq!(decoded, target);
}
#[tokio::test]
async fn protected_udp_stream_relays_datagrams_to_a_real_udp_target() {
let destination = tokio::net::UdpSocket::bind("127.0.0.1:0").await.unwrap();
let destination_address = destination.local_addr().unwrap();
let echo = tokio::spawn(async move {
let mut buffer = [0_u8; 64];
let (length, peer) = destination.recv_from(&mut buffer).await.unwrap();
destination.send_to(&buffer[..length], peer).await.unwrap();
});
let identity = Identity::generate().unwrap();
let public = identity.public();
let (mut client_io, mut server_io) = tokio::io::duplex(128 * 1024);
let server_handshake_task = tokio::spawn(async move {
server_handshake(&mut server_io, ProtectionMode::ChaChaPoly, &[public])
.await
.map(|established| (server_io, established))
});
let client_master = client_handshake(&mut client_io, &identity, ProtectionMode::ChaChaPoly)
.await
.unwrap();
let (server_io, server) = server_handshake_task.await.unwrap().unwrap();
let window = 8 * yamux::DEFAULT_CREDIT as usize;
let (client_mux, _) = mux::spawn(client_io, Mode::Client, 8, window).unwrap();
let (server_mux, incoming) = mux::spawn(server_io, Mode::Server, 8, window).unwrap();
let server_session = tokio::spawn(serve_session(
incoming,
server_mux,
server.master,
ProtectionMode::ChaChaPoly,
Duration::from_secs(2),
));
let client = ClientSession::new(client_mux, client_master, ProtectionMode::ChaChaPoly);
let mut protected = client
.open_udp(&Target::ip(destination_address.ip(), destination_address.port()).unwrap())
.await
.unwrap();
protected.send(b"ping").await.unwrap();
let reply = protected.recv().await.unwrap().unwrap();
assert_eq!(&reply, b"ping");
protected.close().await.unwrap();
client.abort().await;
server_session.await.unwrap().unwrap();
echo.await.unwrap();
}
}