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pub mod tcp;
pub mod udp;
use std::{net::SocketAddr, task::Poll, time::Duration};
use anyhow::Result;
use tokio::time::interval;
use crate::{
Service,
config::Ssl,
server::{Switch, buffer::Buffer},
service::{Transport, session::Identifier},
statistics::{Statistics, Stats},
};
pub trait ProviderStream: Send + 'static {
fn read(&mut self) -> impl Future<Output = Result<Buffer>> + Send;
fn write(&mut self, buffer: &[u8]) -> impl Future<Output = Result<()>> + Send;
fn close(&mut self) -> impl Future<Output = ()> + Send;
}
#[allow(unused)]
pub struct ServerOptions {
pub transport: Transport,
pub idle_timeout: u32,
pub listen: SocketAddr,
pub external: SocketAddr,
pub ssl: Option<Ssl>,
pub mtu: usize,
}
pub trait ProviderServer: Sized + Send {
type Stream: ProviderStream;
/// Bind the server to the specified address.
fn bind(options: &ServerOptions) -> impl Future<Output = Result<Self>> + Send;
/// Accept a new connection.
fn accept(&mut self) -> impl Future<Output = Result<Poll<(Self::Stream, SocketAddr)>>> + Send;
/// Get the local address of the listener.
fn local_addr(&self) -> Result<SocketAddr>;
/// Start the server.
fn start(
options: ServerOptions,
service: Service,
statistics: Statistics,
switch: Switch,
) -> impl Future<Output = Result<()>> + Send {
let transport = options.transport;
let idle_timeout = options.idle_timeout as u64;
async move {
let mut listener = Self::bind(&options).await?;
let local_addr = listener.local_addr()?;
log::info!(
"server listening: listen={}, external={}, local addr={local_addr}, transport={transport:?}",
options.listen,
options.external,
);
while let Ok(poll) = listener.accept().await {
let Poll::Ready((mut socket, address)) = poll else {
continue;
};
let id = Identifier {
source: address,
interface: local_addr,
external: options.external,
transport: options.transport,
};
let mut router = service.make_router(id);
let mut receiver = switch.get_receiver(id);
let reporter = statistics.get_reporter(transport);
let service = service.clone();
let switch = switch.clone();
tokio::spawn(async move {
let mut interval = interval(Duration::from_secs(1));
let mut read_delay = 0;
loop {
let mut response_buffer = Buffer::new();
tokio::select! {
Ok(buffer) = socket.read() => {
read_delay = 0;
if let Ok(Some(res)) = router.route(&buffer, &mut response_buffer).await
{
if let Some(relay) = res.relay {
// The channel data needs to be aligned in multiples of 4 in
// tcp. If the channel data is forwarded to tcp, the alignment
// bit needs to be filled, because if the channel data comes
// from udp, it is not guaranteed to be aligned and needs to be
// checked.
if relay.transport == Transport::Tcp && res.method.is_none() {
let pad = response_buffer.len() % 4;
if pad > 0 {
response_buffer.extend_from_slice(&[0u8; 8][..(4 - pad)]);
}
}
switch.send(&relay, response_buffer);
} else {
if socket.write(&response_buffer).await.is_err() {
break;
}
reporter.send(
&id,
&[Stats::SendBytes(response_buffer.len()), Stats::SendPkts(1)],
);
if let Some(method) = res.method && method.is_error() {
reporter.send(&id, &[Stats::ErrorPkts(1)]);
}
}
}
}
Some(bytes) = receiver.recv() => {
if socket.write(&bytes).await.is_err() {
break;
} else {
reporter.send(&id, &[Stats::SendBytes(bytes.len()), Stats::SendPkts(1)]);
}
}
_ = interval.tick() => {
read_delay += 1;
if read_delay >= idle_timeout {
break;
}
}
else => {
break;
}
}
}
// close the socket
socket.close().await;
// When the socket connection is closed, the procedure to close the session is
// process directly once, avoiding the connection being disconnected
// directly without going through the closing
// process.
service.get_session_manager().refresh(&id, 0);
switch.remove(&id);
log::info!(
"socket disconnect: addr={address:?}, interface={local_addr:?}, transport={transport:?}"
);
});
}
log::error!("server shutdown: interface={local_addr:?}, transport={transport:?}");
Ok(())
}
}
}