fix: reuse conn by dst_peer_id, every peer use only 1 quic conn, to fix nat lost problem (#2216)

Cargo.lock

@@ -2291,6 +2291,7 @@ dependencies = [
  "machine-uid",
  "maplit",
  "mimalloc",
+ "moka",
  "multimap",
  "natpmp",
  "netlink-packet-core",
@@ -5103,9 +5104,12 @@ version = "0.12.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a9321642ca94a4282428e6ea4af8cc2ca4eac48ac7a6a4ea8f33f76d0ce70926"
 dependencies = [
+ "async-lock",
  "crossbeam-channel",
  "crossbeam-epoch",
  "crossbeam-utils",
+ "event-listener",
+ "futures-util",
  "loom",
  "parking_lot",
  "portable-atomic",

easytier/Cargo.toml

@@ -70,6 +70,7 @@ async-stream = "0.3.5"
 async-trait = "0.1.74"
 
 dashmap = "6.0"
+moka = { version = "0.12", features = ["future"] }
 timedmap = "=1.0.1"
 
 # for full-path zero-copy

easytier/src/gateway/quic_proxy.rs

@@ -25,6 +25,7 @@ use dashmap::DashMap;
 use derivative::Derivative;
 use derive_more::{Constructor, Deref, DerefMut, From, Into};
 use guarden::defer;
+use moka::future::Cache;
 use prost::Message;
 use quinn::udp::{EcnCodepoint, RecvMeta, Transmit};
 use quinn::{
@@ -43,8 +44,8 @@ use tokio::io::{AsyncReadExt, Join, join};
 use tokio::sync::mpsc::error::TrySendError;
 use tokio::sync::mpsc::{Receiver, Sender, channel};
 use tokio::task::JoinSet;
-use tokio::time::{Instant, timeout};
-use tokio::{join, pin, select};
+use tokio::time::timeout;
+use tokio::{join, select};
 use tokio_util::sync::PollSender;
 use tracing::{debug, error, info, instrument, trace, warn};
 
@@ -279,6 +280,7 @@ impl From<(SendStream, RecvStream)> for QuicStream {
 pub struct NatDstQuicConnector {
     pub(crate) endpoint: Endpoint,
     pub(crate) peer_mgr: Weak<PeerManager>,
+    pub(crate) conn_map: Cache<PeerId, quinn::Connection>,
 }
 
 #[async_trait::async_trait]
@@ -302,7 +304,6 @@ impl NatDstConnector for NatDstQuicConnector {
         };
 
         trace!("quic nat dst: {:?}, dst peers: {:?}", nat_dst, dst_peer_id);
-
         let addr = QuicAddr::new(dst_peer_id, PacketType::QuicSrc).into();
         let header = {
             let conn_data = QuicConnData {
@@ -323,50 +324,65 @@ impl NatDstConnector for NatDstQuicConnector {
             buf.freeze()
         };
 
-        let mut connect_tasks = JoinSet::<Result<QuicStream, Error>>::new();
-        let connect = |tasks: &mut JoinSet<_>| {
+        for attempt in 0..2 {
             let endpoint = self.endpoint.clone();
-            let header = header.clone();
 
-            tasks.spawn(async move {
-                let connection = endpoint.connect(addr, "")?.await?;
-                let mut stream: QuicStream = connection.open_bi().await?.into();
-                stream.writer_mut().write_chunk(header).await?;
-                Ok(stream)
-            });
-        };
-
-        connect(&mut connect_tasks);
-
-        let timer = tokio::time::sleep(Duration::from_millis(200));
-        pin!(timer);
-
-        let mut retry_remain = 5;
-        loop {
-            select! {
-                Some(result) = connect_tasks.join_next() => {
-                    match result {
-                        Ok(Ok(stream)) => return Ok(stream.into()),
-                        _ => {
-                            if connect_tasks.is_empty() {
-                                if retry_remain == 0 {
-                                    return Err(anyhow!("failed to connect to nat dst: {:?}", nat_dst).into())
-                                }
-
-                                retry_remain -= 1;
-                                connect(&mut connect_tasks);
-                                timer.as_mut().reset(Instant::now() + Duration::from_millis(200))
-                            }
-                        }
+            let connection = match self
+                .conn_map
+                .try_get_with(dst_peer_id, async move {
+                    endpoint
+                        .connect(addr, "")
+                        .map_err(|e| anyhow!("quic connect: {:#}", e))?
+                        .await
+                        .map_err(|e| anyhow!("quic connection: {:#}", e))
+                })
+                .await
+            {
+                Ok(conn) => conn,
+                Err(e) => {
+                    if attempt == 0 {
+                        debug!("quic connect failed, retrying: {:#}", e);
+                        tokio::time::sleep(Duration::from_millis(300)).await;
+                        continue;
                     }
+                    return Err(anyhow!("{:#}", e).into());
                 }
-                _ = &mut timer, if retry_remain > 0 => {
-                    retry_remain -= 1;
-                    connect(&mut connect_tasks);
-                    timer.as_mut().reset(Instant::now() + Duration::from_millis(200));
+            };
+
+            let stream: Result<QuicStreamInner, anyhow::Error> = async {
+                let mut stream: QuicStream = connection
+                    .open_bi()
+                    .await
+                    .map_err(|e| anyhow!("open bi: {:#}", e))?
+                    .into();
+                stream.writer_mut().write_chunk(header.clone()).await?;
+                Ok(stream.into())
+            }
+            .await;
+
+            match stream {
+                Ok(stream) => return Ok(stream),
+                Err(error) => {
+                    debug!(
+                        ?dst_peer_id,
+                        attempt,
+                        ?error,
+                        "quic connect: stream setup failed"
+                    );
                 }
             }
+
+            // Evict stale connection;
+            self.conn_map.invalidate(&dst_peer_id).await;
         }
+
+        Err(anyhow!(
+            "quic connect: failed after {} attempts, dst_peer_id={}, nat_dst={}",
+            2,
+            dst_peer_id,
+            nat_dst
+        )
+        .into())
     }
 
     #[inline]
@@ -595,10 +611,17 @@ impl QuicStreamReceiver {
                                         }
                                     };
 
-                                    match Self::establish_stream(stream, ctx.clone()).await {
-                                        Ok(stream) => drop(tasks.spawn(stream)),
-                                        Err(e) => warn!("failed to establish quic stream from {:?}: {:?}", connection.remote_address(), e),
-                                    }
+                                    let ctx = ctx.clone();
+                                    tasks.spawn(async move {
+                                        match Self::establish_stream(stream, ctx).await {
+                                            Ok(transfer_fut) => {
+                                                if let Err(e) = transfer_fut.await {
+                                                    warn!("quic stream transfer error: {:?}", e);
+                                                }
+                                            }
+                                            Err(e) => warn!("failed to establish quic stream: {:?}", e),
+                                        }
+                                    });
                                 }
 
                                 res = tasks.join_next(), if !tasks.is_empty() => {
@@ -840,11 +863,26 @@ impl QuicProxy {
                 return;
             }
 
+            let conn_map = Cache::builder()
+                .max_capacity(u8::MAX.into()) // same with max_concurrent_bidi_streams, can be increased
+                .time_to_idle(Duration::from_secs(600))
+                .build();
+
+            let conn_map_bg = conn_map.clone();
+            self.tasks.spawn(async move {
+                let mut interval = tokio::time::interval(Duration::from_secs(60));
+                loop {
+                    interval.tick().await;
+                    conn_map_bg.run_pending_tasks().await;
+                }
+            });
+
             let tcp_proxy = TcpProxyForQuicSrc(TcpProxy::new(
                 peer_mgr.clone(),
                 NatDstQuicConnector {
                     endpoint: endpoint.clone(),
                     peer_mgr: Arc::downgrade(&peer_mgr),
+                    conn_map,
                 },
             ));