improve client interface specificity and composability which eliminates much unnecessary code

client/client_test.go

@@ -47,7 +47,7 @@ func (m *MockTransport) RoundTrip(req *http.Request) (*http.Response, error) {
 
 type FakeDialer struct{}
 
-func (w FakeDialer) Catch() (*webRTCConn, error) {
+func (w FakeDialer) Catch() (Snowflake, error) {
 	fmt.Println("Caught a dummy snowflake.")
 	return &webRTCConn{}, nil
 }
@@ -65,57 +65,10 @@ func (f FakeSocksConn) Grant(addr *net.TCPAddr) error { return nil }
 
 type FakePeers struct{ toRelease *webRTCConn }
 
-func (f FakePeers) Collect() error   { return nil }
-func (f FakePeers) Pop() *webRTCConn { return nil }
+func (f FakePeers) Collect() error { return nil }
+func (f FakePeers) Pop() Snowflake { return nil }
 
 func TestSnowflakeClient(t *testing.T) {
-	SkipConvey("WebRTC ConnectLoop", t, func() {
-		Convey("WebRTC ConnectLoop continues until capacity of 1.\n", func() {
-			snowflakes := NewPeers(1)
-			snowflakes.Tongue = FakeDialer{}
-
-			go ConnectLoop(snowflakes)
-			// <-snowflakes.maxedChan
-
-			So(snowflakes.Count(), ShouldEqual, 1)
-			r := <-snowflakes.snowflakeChan
-			So(r, ShouldNotBeNil)
-			So(snowflakes.Count(), ShouldEqual, 0)
-		})
-
-		Convey("WebRTC ConnectLoop continues until capacity of 3.\n", func() {
-			snowflakes := NewPeers(3)
-			snowflakes.Tongue = FakeDialer{}
-
-			go ConnectLoop(snowflakes)
-			// <-snowflakes.maxedChan
-			So(snowflakes.Count(), ShouldEqual, 3)
-			<-snowflakes.snowflakeChan
-			<-snowflakes.snowflakeChan
-			<-snowflakes.snowflakeChan
-			So(snowflakes.Count(), ShouldEqual, 0)
-		})
-
-		Convey("WebRTC ConnectLoop continues filling when Snowflakes disconnect.\n", func() {
-			snowflakes := NewPeers(3)
-			snowflakes.Tongue = FakeDialer{}
-
-			go ConnectLoop(snowflakes)
-			// <-snowflakes.maxedChan
-			So(snowflakes.Count(), ShouldEqual, 3)
-
-			r := <-snowflakes.snowflakeChan
-			So(snowflakes.Count(), ShouldEqual, 2)
-			r.Close()
-			// <-snowflakes.maxedChan
-			So(snowflakes.Count(), ShouldEqual, 3)
-
-			<-snowflakes.snowflakeChan
-			<-snowflakes.snowflakeChan
-			<-snowflakes.snowflakeChan
-			So(snowflakes.Count(), ShouldEqual, 0)
-		})
-	})
 
 	Convey("Peers", t, func() {
 		Convey("Can construct", func() {
@@ -183,6 +136,17 @@ func TestSnowflakeClient(t *testing.T) {
 			So(p.Count(), ShouldEqual, 2)
 		})
 
+		Convey("End Closes all peers.", func() {
+			cnt := 5
+			p := NewPeers(cnt)
+			for i := 0; i < cnt; i++ {
+				p.activePeers.PushBack(&webRTCConn{})
+			}
+			So(p.Count(), ShouldEqual, cnt)
+			p.End()
+			So(p.Count(), ShouldEqual, 0)
+		})
+
 	})
 
 	Convey("Snowflake", t, func() {
@@ -253,6 +217,29 @@ func TestSnowflakeClient(t *testing.T) {
 		})
 	})
 
+	Convey("Dialers", t, func() {
+		Convey("Can construct WebRTCDialer.", func() {
+			broker := &BrokerChannel{Host: "test"}
+			d := NewWebRTCDialer(broker, nil)
+			So(d, ShouldNotBeNil)
+			So(d.BrokerChannel, ShouldNotBeNil)
+			So(d.BrokerChannel.Host, ShouldEqual, "test")
+		})
+		Convey("WebRTCDialer cannot Catch a snowflake with nil broker.", func() {
+			d := NewWebRTCDialer(nil, nil)
+			conn, err := d.Catch()
+			So(conn, ShouldBeNil)
+			So(err, ShouldNotBeNil)
+		})
+		SkipConvey("WebRTCDialer can Catch a snowflake.", func() {
+			broker := &BrokerChannel{Host: "test"}
+			d := NewWebRTCDialer(broker, nil)
+			conn, err := d.Catch()
+			So(conn, ShouldBeNil)
+			So(err, ShouldNotBeNil)
+		})
+	})
+
 	Convey("Rendezvous", t, func() {
 		webrtc.SetLoggingVerbosity(0)
 		transport := &MockTransport{http.StatusOK}

client/interfaces.go

@@ -1,13 +1,31 @@
-// In the Client context, "Snowflake" refers to a remote browser proxy.
 package main
 
 import (
+	"io"
 	"net"
 )
 
+type Connector interface {
+	Connect() error
+}
+
+type Resetter interface {
+	Reset()
+	WaitForReset()
+}
+
+// Interface for a single remote WebRTC peer.
+// In the Client context, "Snowflake" refers to the remote browser proxy.
+type Snowflake interface {
+	io.ReadWriter
+	Resetter
+	Connector
+	Close() error
+}
+
 // Interface for catching Snowflakes. (aka the remote dialer)
 type Tongue interface {
-	Catch() (*webRTCConn, error)
+	Catch() (Snowflake, error)
 }
 
 // Interface for collecting some number of Snowflakes, for passing along
@@ -19,7 +37,7 @@ type SnowflakeCollector interface {
 	Collect() error
 
 	// Remove and return the most available Snowflake from the collection.
-	Pop() *webRTCConn
+	Pop() Snowflake
 }
 
 // Interface to adapt to goptlib's SocksConn struct.

client/peers.go

@@ -22,7 +22,7 @@ type Peers struct {
 	Tongue
 	BytesLogger
 
-	snowflakeChan chan *webRTCConn
+	snowflakeChan chan Snowflake
 	activePeers   *list.List
 	capacity      int
 }
@@ -31,7 +31,7 @@ type Peers struct {
 func NewPeers(max int) *Peers {
 	p := &Peers{capacity: max}
 	// Use buffered go channel to pass snowflakes onwards to the SOCKS handler.
-	p.snowflakeChan = make(chan *webRTCConn, max)
+	p.snowflakeChan = make(chan Snowflake, max)
 	p.activePeers = list.New()
 	return p
 }
@@ -59,7 +59,7 @@ func (p *Peers) Collect() error {
 }
 
 // As part of |SnowflakeCollector| interface.
-func (p *Peers) Pop() *webRTCConn {
+func (p *Peers) Pop() Snowflake {
 
 	// Blocks until an available snowflake appears.
 	snowflake, ok := <-p.snowflakeChan
@@ -67,7 +67,7 @@ func (p *Peers) Pop() *webRTCConn {
 		return nil
 	}
 	// Set to use the same rate-limited traffic logger to keep consistency.
-	snowflake.BytesLogger = p.BytesLogger
+	snowflake.(*webRTCConn).BytesLogger = p.BytesLogger
 	return snowflake
 }
 

client/rendezvous.go

@@ -128,7 +128,7 @@ func NewWebRTCDialer(
 }
 
 // Initialize a WebRTC Connection by signaling through the broker.
-func (w WebRTCDialer) Catch() (*webRTCConn, error) {
+func (w WebRTCDialer) Catch() (Snowflake, error) {
 	if nil == w.BrokerChannel {
 		return nil, errors.New("Cannot Dial WebRTC without a BrokerChannel.")
 	}
@@ -174,7 +174,7 @@ func NewCopyPasteDialer(iceServers IceServerList) *CopyPasteDialer {
 }
 
 // Initialize a WebRTC connection via manual copy-paste.
-func (d *CopyPasteDialer) Catch() (*webRTCConn, error) {
+func (d *CopyPasteDialer) Catch() (Snowflake, error) {
 	if nil == d.signal {
 		return nil, errors.New("Cannot copy-paste dial without signal pipe.")
 	}

client/snowflake.go

@@ -26,21 +26,6 @@ const (
 // ends, -1 is written.
 var handlerChan = make(chan int)
 
-func copyLoop(a, b net.Conn) {
-	var wg sync.WaitGroup
-	wg.Add(2)
-	go func() {
-		io.Copy(b, a)
-		wg.Done()
-	}()
-	go func() {
-		io.Copy(a, b)
-		wg.Done()
-	}()
-	wg.Wait()
-	log.Println("copy loop ended")
-}
-
 // Maintain |SnowflakeCapacity| number of available WebRTC connections, to
 // transfer to the Tor SOCKS handler when needed.
 func ConnectLoop(snowflakes SnowflakeCollector) {
@@ -104,11 +89,28 @@ func handler(socks SocksConnector, snowflakes SnowflakeCollector) error {
 
 	// When WebRTC resets, close the SOCKS connection, which induces new handler.
 	// TODO: Double check this / fix it.
-	<-snowflake.reset
+	snowflake.WaitForReset()
 	log.Println("---- Closed ---")
 	return nil
 }
 
+// Exchanges bytes between two ReadWriters.
+// (In this case, between a SOCKS and WebRTC connection.)
+func copyLoop(a, b io.ReadWriter) {
+	var wg sync.WaitGroup
+	wg.Add(2)
+	go func() {
+		io.Copy(b, a)
+		wg.Done()
+	}()
+	go func() {
+		io.Copy(a, b)
+		wg.Done()
+	}()
+	wg.Wait()
+	log.Println("copy loop ended")
+}
+
 func main() {
 	webrtc.SetLoggingVerbosity(1)
 	logFile, err := os.OpenFile("snowflake.log",

client/webrtc.go

@@ -3,15 +3,15 @@ package main
 import (
 	"bytes"
 	"errors"
-	"fmt"
 	"github.com/keroserene/go-webrtc"
 	"io"
 	"log"
-	"net"
 	"time"
 )
 
-// Remote WebRTC peer.  Implements the |net.Conn| interface.
+// Remote WebRTC peer.
+// Implements the |Snowflake| interface, which includes
+// |io.ReadWriter|, |Resetter|, and |Connector|.
 type webRTCConn struct {
 	config    *webrtc.Configuration
 	pc        *webrtc.PeerConnection
@@ -33,11 +33,14 @@ type webRTCConn struct {
 	BytesLogger
 }
 
+// Read bytes from remote WebRTC.
+// As part of |io.ReadWriter|
 func (c *webRTCConn) Read(b []byte) (int, error) {
 	return c.recvPipe.Read(b)
 }
 
-// Writes bytes out to the snowflake proxy.
+// Writes bytes out to remote WebRTC.
+// As part of |io.ReadWriter|
 func (c *webRTCConn) Write(b []byte) (int, error) {
 	c.BytesLogger.AddOutbound(len(b))
 	if nil == c.snowflake {
@@ -49,6 +52,7 @@ func (c *webRTCConn) Write(b []byte) (int, error) {
 	return len(b), nil
 }
 
+// As part of |Snowflake|
 func (c *webRTCConn) Close() error {
 	var err error = nil
 	log.Printf("WebRTC: Closing")
@@ -67,25 +71,17 @@ func (c *webRTCConn) Close() error {
 	return err
 }
 
-func (c *webRTCConn) LocalAddr() net.Addr {
-	return nil
+// As part of |Resetter|
+func (c *webRTCConn) Reset() {
+	go func() {
+		c.reset <- struct{}{}
+		log.Println("WebRTC resetting...")
+	}()
+	c.Close()
 }
 
-func (c *webRTCConn) RemoteAddr() net.Addr {
-	return nil
-}
-
-func (c *webRTCConn) SetDeadline(t time.Time) error {
-	return fmt.Errorf("SetDeadline not implemented")
-}
-
-func (c *webRTCConn) SetReadDeadline(t time.Time) error {
-	return fmt.Errorf("SetReadDeadline not implemented")
-}
-
-func (c *webRTCConn) SetWriteDeadline(t time.Time) error {
-	return fmt.Errorf("SetWriteDeadline not implemented")
-}
+// As part of |Resetter|
+func (c *webRTCConn) WaitForReset() { <-c.reset }
 
 // Construct a WebRTC PeerConnection.
 func NewWebRTCConnection(config *webrtc.Configuration,
@@ -108,6 +104,7 @@ func NewWebRTCConnection(config *webrtc.Configuration,
 	return connection
 }
 
+// As part of |Connector| interface.
 func (c *webRTCConn) Connect() error {
 	log.Printf("Establishing WebRTC connection #%d...", c.index)
 	// TODO: When go-webrtc is more stable, it's possible that a new
@@ -287,14 +284,6 @@ func (c *webRTCConn) exchangeSDP() error {
 	return nil
 }
 
-func (c *webRTCConn) Reset() {
-	go func() {
-		c.reset <- struct{}{}
-		log.Println("WebRTC resetting...")
-	}()
-	c.Close()
-}
-
 func (c *webRTCConn) cleanup() {
 	if nil != c.snowflake {
 		log.Printf("WebRTC: closing DataChannel")