[tor-commits] [snowflake/master] Revert abstracting copyloop

[arlo at torproject.org]

commit 7092b2cb2c24759286f3ecc7713ad30115415e41
Author: Arlo Breault <arlolra at gmail.com>
Date:   Thu Nov 21 19:33:39 2019 -0500

    Revert abstracting copyloop
---
 common/websocketconn/websocketconn.go      | 19 ----------------
 common/websocketconn/websocketconn_test.go | 30 -------------------------
 proxy-go/proxy-go_test.go                  | 19 ++++++++++++++++
 proxy-go/snowflake.go                      | 18 ++++++++++++++-
 server/server.go                           | 36 +++++++++++++++++++++++++++---
 5 files changed, 69 insertions(+), 53 deletions(-)

diff --git a/common/websocketconn/websocketconn.go b/common/websocketconn/websocketconn.go
index 399cbaa..7e12abf 100644
--- a/common/websocketconn/websocketconn.go
+++ b/common/websocketconn/websocketconn.go
@@ -2,8 +2,6 @@ package websocketconn
 
 import (
 	"io"
-	"log"
-	"sync"
 	"time"
 
 	"github.com/gorilla/websocket"
@@ -70,20 +68,3 @@ func NewWebSocketConn(ws *websocket.Conn) WebSocketConn {
 	conn.Ws = ws
 	return conn
 }
-
-// Copy from WebSocket to socket and vice versa.
-func CopyLoop(c1 io.ReadWriteCloser, c2 io.ReadWriteCloser) {
-	var wg sync.WaitGroup
-	copyer := func(dst io.ReadWriteCloser, src io.ReadWriteCloser) {
-		defer wg.Done()
-		if _, err := io.Copy(dst, src); err != nil {
-			log.Printf("io.Copy inside CopyLoop generated an error: %v", err)
-		}
-		dst.Close()
-		src.Close()
-	}
-	wg.Add(2)
-	go copyer(c1, c2)
-	go copyer(c2, c1)
-	wg.Wait()
-}
diff --git a/common/websocketconn/websocketconn_test.go b/common/websocketconn/websocketconn_test.go
deleted file mode 100644
index 3293165..0000000
--- a/common/websocketconn/websocketconn_test.go
+++ /dev/null
@@ -1,30 +0,0 @@
-package websocketconn
-
-import (
-	"net"
-	"testing"
-
-	. "github.com/smartystreets/goconvey/convey"
-)
-
-func TestWebsocketConn(t *testing.T) {
-	Convey("CopyLoop", t, func() {
-		c1, s1 := net.Pipe()
-		c2, s2 := net.Pipe()
-		go CopyLoop(s1, s2)
-		go func() {
-			bytes := []byte("Hello!")
-			c1.Write(bytes)
-		}()
-		bytes := make([]byte, 6)
-		n, err := c2.Read(bytes)
-		So(n, ShouldEqual, 6)
-		So(err, ShouldEqual, nil)
-		So(bytes, ShouldResemble, []byte("Hello!"))
-		s1.Close()
-
-		// Check that copy loop has closed other connection
-		_, err = s2.Write(bytes)
-		So(err, ShouldNotBeNil)
-	})
-}
diff --git a/proxy-go/proxy-go_test.go b/proxy-go/proxy-go_test.go
index 538957b..ebe4381 100644
--- a/proxy-go/proxy-go_test.go
+++ b/proxy-go/proxy-go_test.go
@@ -374,4 +374,23 @@ func TestUtilityFuncs(t *testing.T) {
 		sid2 := genSessionID()
 		So(sid1, ShouldNotEqual, sid2)
 	})
+	Convey("CopyLoop", t, func() {
+		c1, s1 := net.Pipe()
+		c2, s2 := net.Pipe()
+		go CopyLoop(s1, s2)
+		go func() {
+			bytes := []byte("Hello!")
+			c1.Write(bytes)
+		}()
+		bytes := make([]byte, 6)
+		n, err := c2.Read(bytes)
+		So(n, ShouldEqual, 6)
+		So(err, ShouldEqual, nil)
+		So(bytes, ShouldResemble, []byte("Hello!"))
+		s1.Close()
+
+		//Check that copy loop has closed other connection
+		_, err = s2.Write(bytes)
+		So(err, ShouldNotBeNil)
+	})
 }
diff --git a/proxy-go/snowflake.go b/proxy-go/snowflake.go
index 0e14eb2..c10093a 100644
--- a/proxy-go/snowflake.go
+++ b/proxy-go/snowflake.go
@@ -240,6 +240,22 @@ func (b *Broker) sendAnswer(sid string, pc *webrtc.PeerConnection) error {
 	return nil
 }
 
+func CopyLoop(c1 io.ReadWriteCloser, c2 io.ReadWriteCloser) {
+	var wg sync.WaitGroup
+	copyer := func(dst io.ReadWriteCloser, src io.ReadWriteCloser) {
+		defer wg.Done()
+		if _, err := io.Copy(dst, src); err != nil {
+			log.Printf("io.Copy inside CopyLoop generated an error: %v", err)
+		}
+		dst.Close()
+		src.Close()
+	}
+	wg.Add(2)
+	go copyer(c1, c2)
+	go copyer(c2, c1)
+	wg.Wait()
+}
+
 // We pass conn.RemoteAddr() as an additional parameter, rather than calling
 // conn.RemoteAddr() inside this function, as a workaround for a hang that
 // otherwise occurs inside of conn.pc.RemoteDescription() (called by
@@ -272,7 +288,7 @@ func datachannelHandler(conn *webRTCConn, remoteAddr net.Addr) {
 	wsConn := websocketconn.NewWebSocketConn(ws)
 	log.Printf("connected to relay")
 	defer wsConn.Close()
-	websocketconn.CopyLoop(conn, &wsConn)
+	CopyLoop(conn, &wsConn)
 	log.Printf("datachannelHandler ends")
 }
 
diff --git a/server/server.go b/server/server.go
index d950ddc..e3f4c6f 100644
--- a/server/server.go
+++ b/server/server.go
@@ -15,6 +15,7 @@ import (
 	"os/signal"
 	"path/filepath"
 	"strings"
+	"sync"
 	"syscall"
 	"time"
 
@@ -50,6 +51,35 @@ additional HTTP listener on port 80 to work with ACME.
 	flag.PrintDefaults()
 }
 
+// Copy from WebSocket to socket and vice versa.
+func proxy(local *net.TCPConn, conn *websocketconn.WebSocketConn) {
+	var wg sync.WaitGroup
+	wg.Add(2)
+
+	go func() {
+		if _, err := io.Copy(conn, local); err != nil {
+			log.Printf("error copying ORPort to WebSocket %v", err)
+		}
+		if err := local.CloseRead(); err != nil {
+			log.Printf("error closing read after copying ORPort to WebSocket %v", err)
+		}
+		conn.Close()
+		wg.Done()
+	}()
+	go func() {
+		if _, err := io.Copy(local, conn); err != nil {
+			log.Printf("error copying WebSocket to ORPort")
+		}
+		if err := local.CloseWrite(); err != nil {
+			log.Printf("error closing write after copying WebSocket to ORPort %v", err)
+		}
+		conn.Close()
+		wg.Done()
+	}()
+
+	wg.Wait()
+}
+
 // Return an address string suitable to pass into pt.DialOr.
 func clientAddr(clientIPParam string) string {
 	if clientIPParam == "" {
@@ -75,8 +105,8 @@ func (handler *HTTPHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	wsConn := websocketconn.NewWebSocketConn(ws)
-	defer wsConn.Close()
+	conn := websocketconn.NewWebSocketConn(ws)
+	defer conn.Close()
 
 	// Pass the address of client as the remote address of incoming connection
 	clientIPParam := r.URL.Query().Get("client_ip")
@@ -93,7 +123,7 @@ func (handler *HTTPHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	}
 	defer or.Close()
 
-	websocketconn.CopyLoop(or, &wsConn)
+	proxy(or, &conn)
 }
 
 func initServer(addr *net.TCPAddr,