feat: better proxy handling

client.go

@@ -5,10 +5,13 @@ import (
 	"io"
 	"net"
 	"net/http"
+	"os"
+	"strconv"
 
 	"gitlab.com/wpetit/goweb/logger"
 
 	"forge.cadoles.com/wpetit/go-tunnel/control"
+	cmap "github.com/orcaman/concurrent-map"
 	"github.com/pkg/errors"
 	"github.com/xtaci/kcp-go/v5"
 	"github.com/xtaci/smux"
@@ -20,6 +23,7 @@ type Client struct {
 	sess    *smux.Session
 	control *control.Control
 	http    *http.Client
+	proxies cmap.ConcurrentMap
 }
 
 func (c *Client) Connect(ctx context.Context) error {
@@ -70,6 +74,7 @@ func (c *Client) Listen(ctx context.Context) error {
 
 	err := c.control.Listen(ctx, control.Handlers{
 		control.TypeProxyRequest: c.handleProxyRequest,
+		control.TypeCloseProxy:   c.handleCloseProxy,
 	})
 
 	if errors.Is(err, io.ErrClosedPipe) {
@@ -99,28 +104,95 @@ func (c *Client) Close() error {
 	return nil
 }
 
+func (c *Client) handleCloseProxy(ctx context.Context, m *control.Message) (*control.Message, error) {
+	closeProxyPayload, ok := m.Payload.(*control.CloseProxyPayload)
+	if !ok {
+		return nil, errors.WithStack(ErrUnexpectedMessage)
+	}
+
+	requestID := strconv.FormatInt(closeProxyPayload.RequestID, 10)
+
+	rawCloseChan, exists := c.proxies.Get(requestID)
+	if !exists {
+		return nil, nil
+	}
+
+	closeChan, ok := rawCloseChan.(chan struct{})
+	if !ok {
+		return nil, nil
+	}
+
+	closeChan <- struct{}{}
+
+	return nil, nil
+}
+
 func (c *Client) handleProxyRequest(ctx context.Context, m *control.Message) (*control.Message, error) {
 	proxyReqPayload, ok := m.Payload.(*control.ProxyRequestPayload)
 	if !ok {
 		return nil, errors.WithStack(ErrUnexpectedMessage)
 	}
 
+	requestID := strconv.FormatInt(proxyReqPayload.RequestID, 10)
+
+	ctx = logger.With(ctx, logger.F("requestID", requestID))
+
+	logger.Debug(
+		ctx, "handling proxy request",
+		logger.F("network", proxyReqPayload.Network),
+		logger.F("address", proxyReqPayload.Address),
+	)
+
 	stream, err := c.sess.OpenStream()
 	if err != nil {
 		return nil, errors.WithStack(err)
 	}
 
-	defer stream.Close()
+	closeChan := make(chan struct{})
 
+	go func() {
+		defer func() {
+			stream.Close()
+			logger.Debug(ctx, "proxy stream closed")
+		}()
+
+		proxy := func() error {
 			net, err := net.Dial(proxyReqPayload.Network, proxyReqPayload.Address)
 			if err != nil {
-		return nil, errors.WithStack(err)
+				return errors.WithStack(err)
+			}
+			defer net.Close()
+
+			err = pipe(ctx, stream, net)
+			if errors.Is(err, os.ErrClosed) {
+				return nil
 			}
 
-	if err := pipe(stream, net); err != nil {
-		return nil, errors.WithStack(err)
+			if err != nil {
+				return errors.WithStack(err)
 			}
 
+			return nil
+		}
+
+		for {
+			select {
+			case <-closeChan:
+				return
+			default:
+				if err := proxy(); err != nil {
+					logger.Error(ctx, "error while proxying", logger.E(err))
+
+					continue
+				}
+
+				return
+			}
+		}
+	}()
+
+	c.proxies.Set(requestID, closeChan)
+
 	return nil, nil
 }
 
@@ -134,5 +206,6 @@ func NewClient(funcs ...ClientConfigFunc) *Client {
 	return &Client{
 		conf:    conf,
 		http:    &http.Client{},
+		proxies: cmap.New(),
 	}
 }

control/control.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"encoding/json"
 	"net"
+	"sync/atomic"
 	"time"
 
 	"github.com/pkg/errors"
@@ -16,6 +17,7 @@ type Control struct {
 	decoder    *json.Decoder
 	stream     *smux.Stream
 	sess       *smux.Session
+	proxyClock int64
 }
 
 func (c *Control) AuthRequest(credentials interface{}) (bool, error) {
@@ -37,15 +39,16 @@ func (c *Control) AuthRequest(credentials interface{}) (bool, error) {
 	return authResPayload.Success, nil
 }
 
-type CloseStream func()
-
 func (c *Control) Proxy(ctx context.Context, network, address string) (net.Conn, error) {
 	var (
 		stream *smux.Stream
 		err    error
 	)
 
+	requestID := atomic.AddInt64(&c.proxyClock, 1)
+
 	req := NewMessage(TypeProxyRequest, &ProxyRequestPayload{
+		RequestID: requestID,
 		Network:   network,
 		Address:   address,
 	})
@@ -65,6 +68,21 @@ func (c *Control) Proxy(ctx context.Context, network, address string) (net.Conn,
 		return nil, errors.WithStack(err)
 	}
 
+	go func() {
+		<-ctx.Done()
+
+		req := NewMessage(TypeCloseProxy, &CloseProxyPayload{
+			RequestID: requestID,
+		})
+
+		if err := c.Write(req); err != nil {
+			logger.Error(ctx, "error while closing proxy", logger.E(err))
+		}
+
+		logger.Debug(ctx, "closing proxy conn")
+		stream.Close()
+	}()
+
 	return stream, nil
 }
 

control/message.go

@@ -10,6 +10,7 @@ const (
 	TypeAuthRequest  MessageType = "auth-req"
 	TypeAuthResponse MessageType = "auth-res"
 	TypeProxyRequest MessageType = "proxy-req"
+	TypeCloseProxy   MessageType = "close-proxy"
 )
 
 type MessageType string
@@ -61,6 +62,8 @@ func unmarshalPayload(mType MessageType, data []byte) (interface{}, error) {
 		payload = &AuthResponsePayload{}
 	case TypeProxyRequest:
 		payload = &ProxyRequestPayload{}
+	case TypeCloseProxy:
+		payload = &CloseProxyPayload{}
 	default:
 		return nil, errors.Wrapf(ErrUnexpectedMessage, "unexpected message type '%s'", mType)
 	}

control/proxy.go

@@ -1,6 +1,11 @@
 package control
 
 type ProxyRequestPayload struct {
+	RequestID int64  `json:"i"`
 	Network   string `json:"n"`
 	Address   string `json:"a"`
 }
+
+type CloseProxyPayload struct {
+	RequestID int64 `json:"i"`
+}

helper.go

@@ -1,18 +1,30 @@
 package tunnel
 
 import (
+	"context"
 	"io"
 	"net"
+
+	"github.com/pkg/errors"
+	"gitlab.com/wpetit/goweb/logger"
 )
 
-func pipe(client net.Conn, server net.Conn) (err error) {
+func pipe(ctx context.Context, client net.Conn, server net.Conn) (err error) {
 	stop := make(chan bool)
 
 	go func() {
 		err = relay(client, server, stop)
+		if err != nil {
+			err = errors.WithStack(err)
+			logger.Debug(ctx, "client->server error", logger.E(err))
+		}
 	}()
 	go func() {
 		err = relay(server, client, stop)
+		if err != nil {
+			err = errors.WithStack(err)
+			logger.Debug(ctx, "server->client error", logger.E(err))
+		}
 	}()
 
 	select {
@@ -21,11 +33,15 @@ func pipe(client net.Conn, server net.Conn) (err error) {
 	}
 }
 
-func relay(src io.ReadCloser, dst io.WriteCloser, stop chan bool) (err error) {
+func relay(src net.Conn, dst net.Conn, stop chan bool) (err error) {
 	_, err = io.Copy(dst, src)
+	if errors.Is(err, io.EOF) {
+		err = nil
+	}
 
-	dst.Close()
-	src.Close()
+	if err != nil {
+		err = errors.WithStack(err)
+	}
 
 	stop <- true
 

remote_client.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"io"
 	"net"
+	"time"
 
 	"forge.cadoles.com/wpetit/go-tunnel/control"
 
@@ -41,6 +42,10 @@ func (c *RemoteClient) Accept(ctx context.Context, conn *kcp.UDPSession) error {
 
 	logger.Debug(ctx, "accepting control stream")
 
+	if err := sess.SetDeadline(time.Now().Add(30 * time.Second)); err != nil {
+		return errors.WithStack(err)
+	}
+
 	controlStream, err := sess.AcceptStream()
 	if err != nil {
 		return errors.WithStack(err)
@@ -92,6 +97,8 @@ func (c *RemoteClient) handleAuthRequest(ctx context.Context, m *control.Message
 		}
 	}
 
+	logger.Debug(ctx, "auth succeeded", logger.F("credentials", authReqPayload.Credentials))
+
 	res := control.NewMessage(control.TypeAuthResponse, &control.AuthResponsePayload{
 		Success: success,
 	})