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use std::sync::Arc;
use futures::future::try_join;
use std::collections::HashMap;
use std::net::SocketAddr;
use std::time::SystemTime;
use std::io::ErrorKind::Other;
use tokio::net::UdpSocket;
use tokio::time;
use log::*;
use futures::StreamExt;
use futures::{
channel::{
mpsc::{
UnboundedReceiver,
UnboundedSender,
unbounded
}
}
};
use tokio_util::sync::CancellationToken;
use crate::dns::DNSResolve;
use rproxy::Settings;
#[allow(dead_code)]
enum MessageType{
Data,
Terminate,
DNS
}
type Tx=UnboundedSender<(SocketAddr, Vec<u8>, MessageType)>;
type Rx=UnboundedReceiver<(SocketAddr, Vec<u8>, MessageType)>;
struct UDPPeerPair {
client: SocketAddr,
remote: SocketAddr,
send: Tx,
recv: Rx
}
impl UDPPeerPair {
async fn run(mut self) -> Result<(), std::io::Error>{
let socket = Arc::new(UdpSocket::bind("0.0.0.0:0").await.unwrap());
// let (mut socket_recv, mut socket_send) = socket.split();
let socket_recv = socket.clone();
let socket_send = socket.clone();
let client_peer = self.client;
let _tx = self.send.clone();
let remote_addr = self.remote;
let (ctrl_tx, mut ctrl_rx) = unbounded::<MessageType>();
let client_to_remote_proc = async move {
// let mut buf: Vec<u8> = vec![0;1024*10];
loop{
if let Some((_peer, buf, msg_type)) = self.recv.next().await {
match msg_type {
MessageType::Terminate => {
debug!("{}:{} sends TERMINATE signal", client_peer.ip(), client_peer.port());
let _ = ctrl_tx.unbounded_send(MessageType::Terminate);
break;
},
_ => {}
}
// debug!("Forward {} bytes from {}", buf.len(), _peer);
match socket_send.send_to(&buf[..], &remote_addr).await {
Ok(_sz) => {
},
Err(e) => {
warn!("{}:{} send_to failed: {:?}", client_peer.ip(), client_peer.port(), e);
let _ = ctrl_tx.unbounded_send(MessageType::Terminate);
break;
}
}
} else {
// Channel closed — sender was dropped (client timed out or cleaned up)
debug!("{}:{} channel closed", client_peer.ip(), client_peer.port());
let _ = ctrl_tx.unbounded_send(MessageType::Terminate);
break;
}
}
Ok(())
};
let remote_to_client_proc = async move {
let mut buf: Vec<u8> = vec![0;1024*10];
loop{
tokio::select! {
x = socket_recv.recv_from(&mut buf) => {
if let Ok((_size, _peer)) = x {
// debug!("Recv {} bytes to {}", _size, client_peer);
match _tx.unbounded_send((client_peer, Vec::from(&buf[.._size]), MessageType::Data)) {
Ok(_sz) => {
},
Err(_e) => {
return Err(std::io::Error::from(Other));
}
}
}
},
y = ctrl_rx.next() => {
if let Some(msg_type) = y{
match msg_type{
MessageType::Terminate => {
debug!("{}:{} recvs TERMINATE signal", client_peer.ip(), client_peer.port());
break;
},
_ =>{
}
}
} else {
// ctrl channel closed — other side exited
debug!("{}:{} ctrl channel closed", client_peer.ip(), client_peer.port());
break;
}
}
}
}
Ok(())
};
let _ = try_join(client_to_remote_proc, remote_to_client_proc).await;
debug!("{}:{} exits", client_peer.ip(), client_peer.port());
Ok(())
}
}
struct UDPProxy<'a> {
addr: &'a String,
remote: &'a String,
dns: Vec<String>,
client_tunnels: HashMap<SocketAddr, (Tx, SystemTime)>,
settings: Arc<Settings>,
cancel: CancellationToken,
}
impl<'a> DNSResolve<'a> for UDPProxy<'a>{
fn remote(&self) -> &String {
&self.remote
}
fn dns(&self) -> &Vec<String> {
&self.dns
}
fn reset_dns(&mut self,d: &Vec<String>) -> usize {
self.dns = d.clone();
d.len()
}
}
impl<'a> UDPProxy<'a> {
async fn run(&mut self) -> Result<(), std::io::Error> {
let socket = Arc::new(UdpSocket::bind(&self.addr).await.unwrap());
info!("Listening on {}", socket.local_addr().unwrap());
// let server: Vec<_> = self.remote
// .to_socket_addrs()
// .expect("Unable to resolve domain")
// .collect();
// let _remote = server[0];
self.resolve().await.unwrap();
let mut dns_timeout = time::interval(tokio::time::Duration::from_secs(30));
let mut _remote = self.dns[0].clone();
// let (mut socket_recv, mut socket_send) = socket.split();
let socket_recv = socket.clone();
let socket_send = socket.clone();
let cancel_token = self.cancel.clone();
let (tx, mut rx) = unbounded::<(SocketAddr, Vec<u8>, MessageType)>();
let remote_to_client_proc = async move {
loop{
if let Some((peer, buf, _msg_type)) = rx.next().await {
// debug!("Forward {} bytes to {}", buf.len(), peer);
match socket_send.send_to(&buf[..], &peer).await {
Ok(_sz) => {
},
Err(e) => {
return Err(e);
}
}
} else {
break;
}
}
Ok(())
};
// let mut client_run_procs: Vec<JoinHandle<Result<(), io::Error>> > = Vec::new();
let client_to_proxy_proc = async move {
let mut buf: Vec<u8> = vec![0;1024*256];
let empty: Vec<u8> = vec![0;0];
// let mut client_tunnels:HashMap<SocketAddr, (Tx, SystemTime)> = HashMap::new();
let mut time_out1 = time::interval(tokio::time::Duration::from_secs(5));
loop{
tokio::select! {
data = socket_recv.recv_from(&mut buf) => {
match data {
Ok((size, peer)) => {
// Check if tunnel still has a working channel
let needs_new_tunnel = match self.client_tunnels.get(&peer) {
Some((tx, _)) => tx.is_closed(),
None => true,
};
if needs_new_tunnel {
// Remove stale entry if it exists
if self.client_tunnels.contains_key(&peer) {
info!("Replacing stale tunnel for {}:{}", peer.ip(), peer.port());
self.client_tunnels.remove(&peer);
}
let max_tunnels = self.settings.max_client_tunnels;
if self.client_tunnels.len() >= max_tunnels {
warn!("Client tunnel limit reached ({}), rejecting {}:{}", max_tunnels, peer.ip(), peer.port());
continue;
}
info!("New client {}:{} is added", peer.ip(), peer.port());
let (_s, _r) = unbounded::<(SocketAddr, Vec<u8>, MessageType)>();
self.client_tunnels.insert(peer, (_s, SystemTime::now()));
let c = UDPPeerPair {
client : peer,
remote: _remote.parse::<SocketAddr>().unwrap(),
send: tx.clone(),
recv: _r
};
tokio::spawn(c.run());
}
if let Some((tx, tm)) = self.client_tunnels.get_mut(&peer) {
if let Err(_) = tx.unbounded_send((peer, Vec::from(&buf[..size]), MessageType::Data)) {
warn!("Failed to send data to tunnel for {}:{}, removing", peer.ip(), peer.port());
self.client_tunnels.remove(&peer);
} else {
*tm = SystemTime::now();
}
}
},
Err(e) => {
warn!("recv_from {:?} returned error {}, {:?}", socket_recv, e, e);
break;
}
}
},
_ = dns_timeout.tick() => {
self.resolve().await.unwrap();
_remote = self.dns[0].clone();
},
_ = time_out1.tick() =>{
debug!("Tick");
let mut tbd: Vec<SocketAddr> = Vec::new();
for (k, v) in (&mut self.client_tunnels).iter(){
let sec = v.1.elapsed().unwrap().as_secs();
if sec > 120{
info!("Client {}:{} is timeout({}s)", k.ip(), k.port(), sec);
let _ = v.0.unbounded_send((k.clone(), empty.clone(), MessageType::Terminate));
tbd.push(k.to_owned());
} else {
debug!("Client {}:{} is good. ({}s)", k.ip(), k.port(), sec);
}
}
for k in tbd{
self.client_tunnels.remove(&k);
}
},
_ = cancel_token.cancelled() => {
info!("UDP proxy {} shutting down (existing tunnels will drain)", self.addr);
// Send terminate to all active tunnels
for (k, (tx, _)) in self.client_tunnels.iter() {
let _ = tx.unbounded_send((k.clone(), empty.clone(), MessageType::Terminate));
}
self.client_tunnels.clear();
break;
}
}
}
Ok(())
};
// client_to_proxy_proc.await;
try_join(client_to_proxy_proc, remote_to_client_proc).await.unwrap();
Ok(())
}
}
pub async fn udp_proxy(local: &String,
remote: &String, settings: Arc<Settings>, cancel: CancellationToken) -> Result<(), std::io::Error>
{
info!("Start service in UDP mode {}->{} (max_client_tunnels={})",
local, remote, settings.max_client_tunnels);
let mut server = UDPProxy {
addr: &local,
remote: &remote,
dns: vec![],
client_tunnels: HashMap::new(),
settings,
cancel,
};
return server.run().await;
}