support uploading large file through multipart

README.md

@@ -38,4 +38,5 @@ Basically, this tunnel is primarily for this purpose. If you want to expose your
 	- random subdomain if `--random-subdomain` is specified
 	- random remote port if not specified
 	- support http/1.1
+	  - Upload file
 	- [ ] support http/2

src/client/client.rs

@@ -6,13 +6,14 @@ use tonic::{transport::Channel, Response, Status, Streaming};
 use tracing::{debug, error, info, instrument, span};
 
 use tokio::{
-    io::{self, AsyncRead, AsyncWrite, AsyncWriteExt},
+    io::{self, AsyncRead, AsyncWrite, AsyncWriteExt, BufReader},
     net::{TcpStream, UdpSocket},
     select,
     sync::{mpsc, oneshot},
 };
 
 use crate::{
+    constant,
     io::{StreamingReader, StreamingWriter, TrafficToServerWrapper},
     pb::{
         self, control::Payload, traffic_to_server, tunnel::Type,
@@ -469,14 +470,19 @@ async fn handle_work_traffic(
 /// 1. remote <=> me
 /// 2. me     <=> local
 async fn forward_traffic_to_local(
-    mut local_r: impl AsyncRead + Unpin,
+    local_r: impl AsyncRead + Unpin,
     mut local_w: impl AsyncWrite + Unpin,
-    mut remote_r: StreamingReader<TrafficToClient>,
+    remote_r: StreamingReader<TrafficToClient>,
     mut remote_w: StreamingWriter<TrafficToServer>,
 ) -> Result<()> {
     let remote_to_me_to_local = async {
         // read from remote, write to local
-        match io::copy(&mut remote_r, &mut local_w).await {
+        match io::copy_buf(
+            &mut BufReader::with_capacity(constant::DEFAULT_BUF_SIZE, remote_r),
+            &mut local_w,
+        )
+        .await
+        {
             Ok(n) => {
                 debug!("copied {} bytes from remote to local", n);
                 let _ = local_w.shutdown().await;
@@ -489,7 +495,12 @@ async fn forward_traffic_to_local(
 
     let local_to_me_to_remote = async {
         // read from local, write to remote
-        match io::copy(&mut local_r, &mut remote_w).await {
+        match io::copy_buf(
+            &mut BufReader::with_capacity(constant::DEFAULT_BUF_SIZE, local_r),
+            &mut remote_w,
+        )
+        .await
+        {
             Ok(n) => {
                 debug!("copied {} bytes from local to remote", n);
                 let _ = remote_w.shutdown().await;

src/constant.rs

@@ -0,0 +1,2 @@
+// use 8K as the default buffer size when transferring io data.
+pub(crate) const DEFAULT_BUF_SIZE: usize = 8 * 1024;

src/lib.rs

@@ -1,4 +1,5 @@
 pub(crate) mod bridge;
+pub(crate) mod constant;
 pub(crate) mod event;
 pub(crate) mod helper;
 pub(crate) mod io;

src/server/control_server.rs

@@ -1,7 +1,7 @@
 use crate::event::ClientEventResponse;
 use crate::helper::validate_register_req;
 use crate::pb::{traffic_to_server, TrafficToServer};
-use crate::{bridge, event};
+use crate::{bridge, constant, event};
 use crate::{
     io::CancellableReceiver,
     pb::{
@@ -394,11 +394,25 @@ impl TunnelService for ControlHandler {
                                                 tokio::select! {
                                                     // server -> client
                                                     Some(data) = transfer_rx.recv() => {
-                                                        outbound_tx
-                                                            .send(Ok(TrafficToClient { data }))
-                                                            .await
-                                                            .context("failed to send traffic to outbound channel")
-                                                            .unwrap();
+                                                        if data.len() <= constant::DEFAULT_BUF_SIZE {
+                                                            outbound_tx
+                                                                .send(Ok(TrafficToClient { data }))
+                                                                .await
+                                                                .context("failed to send traffic to outbound channel")
+                                                                .unwrap();
+                                                        } else {
+                                                            // read data chunk by chunk, then send to the client
+                                                            // if data is empty, the first chunk will be none.
+                                                            // which means we have no change to send the data.
+                                                            // so if the length of data is less than 8192, we can send it directly.
+                                                            for data in data.chunks(constant::DEFAULT_BUF_SIZE) {
+                                                                outbound_tx
+                                                                    .send(Ok(TrafficToClient { data: data.to_vec() }))
+                                                                    .await
+                                                                    .context("failed to send traffic to outbound channel")
+                                                                    .unwrap();
+                                                            }
+                                                        }
                                                     }
                                                     _ = close_sender_listener.cancelled() => {
                                                         // after connection is removed, this listener will be notified