nat4-nat4 punch (#388)

this patch optimize the udp hole punch logic:

1. allow start punch hole before stun test complete.
2. add lock to symmetric punch, avoid conflict between concurrent hole punching task.
3. support punching hole for predictable nat4-nat4.
4. make backoff of retry reasonable

easytier/src/connector/udp_hole_punch/cone.rs

@@ -0,0 +1,258 @@
+use std::{
+    sync::Arc,
+    time::{Duration, Instant},
+};
+
+use anyhow::Context;
+use tokio::net::UdpSocket;
+
+use crate::{
+    common::{scoped_task::ScopedTask, stun::StunInfoCollectorTrait, PeerId},
+    connector::udp_hole_punch::common::{
+        try_connect_with_socket, UdpSocketArray, HOLE_PUNCH_PACKET_BODY_LEN,
+    },
+    peers::peer_manager::PeerManager,
+    proto::{
+        common::Void,
+        peer_rpc::{
+            SelectPunchListenerRequest, SendPunchPacketConeRequest, UdpHolePunchRpcClientFactory,
+        },
+        rpc_types::{self, controller::BaseController},
+    },
+    tunnel::{udp::new_hole_punch_packet, Tunnel},
+};
+
+use super::common::PunchHoleServerCommon;
+
+pub(crate) struct PunchConeHoleServer {
+    common: Arc<PunchHoleServerCommon>,
+}
+
+impl PunchConeHoleServer {
+    pub(crate) fn new(common: Arc<PunchHoleServerCommon>) -> Self {
+        Self { common }
+    }
+
+    #[tracing::instrument(skip(self), ret, err)]
+    pub(crate) async fn send_punch_packet_cone(
+        &self,
+        _: BaseController,
+        request: SendPunchPacketConeRequest,
+    ) -> Result<Void, rpc_types::error::Error> {
+        let listener_addr = request.listener_mapped_addr.ok_or(anyhow::anyhow!(
+            "send_punch_packet_for_cone request missing listener_mapped_addr"
+        ))?;
+        let listener_addr = std::net::SocketAddr::from(listener_addr);
+        let listener = self
+            .common
+            .find_listener(&listener_addr)
+            .await
+            .ok_or(anyhow::anyhow!(
+                "send_punch_packet_for_cone failed to find listener"
+            ))?;
+
+        let dest_addr = request.dest_addr.ok_or(anyhow::anyhow!(
+            "send_punch_packet_for_cone request missing dest_addr"
+        ))?;
+        let dest_addr = std::net::SocketAddr::from(dest_addr);
+        let dest_ip = dest_addr.ip();
+        if dest_ip.is_unspecified() || dest_ip.is_multicast() {
+            return Err(anyhow::anyhow!(
+                "send_punch_packet_for_cone dest_ip is malformed, {:?}",
+                request
+            )
+            .into());
+        }
+
+        for _ in 0..request.packet_batch_count {
+            tracing::info!(?request, "sending hole punching packet");
+
+            for _ in 0..request.packet_count_per_batch {
+                let udp_packet =
+                    new_hole_punch_packet(request.transaction_id, HOLE_PUNCH_PACKET_BODY_LEN);
+                if let Err(e) = listener.send_to(&udp_packet.into_bytes(), &dest_addr).await {
+                    tracing::error!(?e, "failed to send hole punch packet to dest addr");
+                }
+            }
+            tokio::time::sleep(Duration::from_millis(request.packet_interval_ms as u64)).await;
+        }
+
+        Ok(Void::default())
+    }
+}
+
+pub(crate) struct PunchConeHoleClient {
+    peer_mgr: Arc<PeerManager>,
+}
+
+impl PunchConeHoleClient {
+    pub(crate) fn new(peer_mgr: Arc<PeerManager>) -> Self {
+        Self { peer_mgr }
+    }
+
+    #[tracing::instrument(skip(self))]
+    pub(crate) async fn do_hole_punching(
+        &self,
+        dst_peer_id: PeerId,
+    ) -> Result<Box<dyn Tunnel>, anyhow::Error> {
+        tracing::info!(?dst_peer_id, "start hole punching");
+        let tid = rand::random();
+
+        let global_ctx = self.peer_mgr.get_global_ctx();
+        let udp_array = UdpSocketArray::new(1, global_ctx.net_ns.clone());
+        let local_socket = {
+            let _g = self.peer_mgr.get_global_ctx().net_ns.guard();
+            Arc::new(UdpSocket::bind("0.0.0.0:0").await?)
+        };
+
+        let local_addr = local_socket
+            .local_addr()
+            .with_context(|| anyhow::anyhow!("failed to get local port from udp array"))?;
+        let local_port = local_addr.port();
+
+        let local_mapped_addr = global_ctx
+            .get_stun_info_collector()
+            .get_udp_port_mapping(local_port)
+            .await
+            .with_context(|| "failed to get udp port mapping")?;
+
+        // client -> server: tell server the mapped port, server will return the mapped address of listening port.
+        let rpc_stub = self
+            .peer_mgr
+            .get_peer_rpc_mgr()
+            .rpc_client()
+            .scoped_client::<UdpHolePunchRpcClientFactory<BaseController>>(
+                self.peer_mgr.my_peer_id(),
+                dst_peer_id,
+                global_ctx.get_network_name(),
+            );
+
+        let resp = rpc_stub
+            .select_punch_listener(
+                BaseController::default(),
+                SelectPunchListenerRequest { force_new: false },
+            )
+            .await
+            .with_context(|| "failed to select punch listener")?;
+        let remote_mapped_addr = resp.listener_mapped_addr.ok_or(anyhow::anyhow!(
+            "select_punch_listener response missing listener_mapped_addr"
+        ))?;
+
+        tracing::debug!(
+            ?local_mapped_addr,
+            ?remote_mapped_addr,
+            "hole punch got remote listener"
+        );
+
+        udp_array.add_new_socket(local_socket).await?;
+        udp_array.add_intreast_tid(tid);
+        let send_from_local = || async {
+            udp_array
+                .send_with_all(
+                    &new_hole_punch_packet(tid, HOLE_PUNCH_PACKET_BODY_LEN).into_bytes(),
+                    remote_mapped_addr.clone().into(),
+                )
+                .await
+                .with_context(|| "failed to send hole punch packet from local")
+        };
+
+        send_from_local().await?;
+
+        let scoped_punch_task: ScopedTask<()> = tokio::spawn(async move {
+            if let Err(e) = rpc_stub
+                .send_punch_packet_cone(
+                    BaseController {
+                        timeout_ms: 4000,
+                        ..Default::default()
+                    },
+                    SendPunchPacketConeRequest {
+                        listener_mapped_addr: Some(remote_mapped_addr.into()),
+                        dest_addr: Some(local_mapped_addr.into()),
+                        transaction_id: tid,
+                        packet_count_per_batch: 2,
+                        packet_batch_count: 5,
+                        packet_interval_ms: 400,
+                    },
+                )
+                .await
+            {
+                tracing::error!(?e, "failed to call remote send punch packet");
+            }
+        })
+        .into();
+
+        // server: will send some punching resps, total 10 packets.
+        // client: use the socket to create UdpTunnel with UdpTunnelConnector
+        // NOTICE: UdpTunnelConnector will ignore the punching resp packet sent by remote.
+        let mut finish_time: Option<Instant> = None;
+        while finish_time.is_none() || finish_time.as_ref().unwrap().elapsed().as_millis() < 1000 {
+            tokio::time::sleep(Duration::from_millis(200)).await;
+
+            if finish_time.is_none() && (*scoped_punch_task).is_finished() {
+                finish_time = Some(Instant::now());
+            }
+
+            let Some(socket) = udp_array.try_fetch_punched_socket(tid) else {
+                tracing::debug!("no punched socket found, send some more hole punch packets");
+                send_from_local().await?;
+                continue;
+            };
+
+            tracing::debug!(?socket, ?tid, "punched socket found, try connect with it");
+
+            for _ in 0..2 {
+                match try_connect_with_socket(socket.socket.clone(), remote_mapped_addr.into())
+                    .await
+                {
+                    Ok(tunnel) => {
+                        tracing::info!(?tunnel, "hole punched");
+                        return Ok(tunnel);
+                    }
+                    Err(e) => {
+                        tracing::error!(?e, "failed to connect with socket");
+                    }
+                }
+            }
+        }
+
+        return Err(anyhow::anyhow!("punch task finished but no hole punched"));
+    }
+}
+
+#[cfg(test)]
+pub mod tests {
+
+    use crate::{
+        connector::udp_hole_punch::{
+            tests::create_mock_peer_manager_with_mock_stun, UdpHolePunchConnector,
+        },
+        peers::tests::{connect_peer_manager, wait_route_appear, wait_route_appear_with_cost},
+        proto::common::NatType,
+    };
+
+    #[tokio::test]
+    async fn hole_punching_cone() {
+        let p_a = create_mock_peer_manager_with_mock_stun(NatType::Restricted).await;
+        let p_b = create_mock_peer_manager_with_mock_stun(NatType::PortRestricted).await;
+        let p_c = create_mock_peer_manager_with_mock_stun(NatType::Restricted).await;
+        connect_peer_manager(p_a.clone(), p_b.clone()).await;
+        connect_peer_manager(p_b.clone(), p_c.clone()).await;
+
+        wait_route_appear(p_a.clone(), p_c.clone()).await.unwrap();
+
+        println!("{:?}", p_a.list_routes().await);
+
+        let mut hole_punching_a = UdpHolePunchConnector::new(p_a.clone());
+        let mut hole_punching_c = UdpHolePunchConnector::new(p_c.clone());
+
+        hole_punching_a.run_as_client().await.unwrap();
+        hole_punching_c.run_as_server().await.unwrap();
+
+        hole_punching_a.client.run_immediately().await;
+
+        wait_route_appear_with_cost(p_a.clone(), p_c.my_peer_id(), Some(1))
+            .await
+            .unwrap();
+        println!("{:?}", p_a.list_routes().await);
+    }
+}