From f45dac1e3884105a3c0fb4824205ff41542e1007 Mon Sep 17 00:00:00 2001
From: Matt Joiner <anacrolix@gmail.com>
Date: Mon, 13 Apr 2020 14:04:34 +1000
Subject: [PATCH] Use offer_id for webrtc conn string

---
 client.go               | 21 ++++++++++++++-------
 peerconn.go             |  3 ++-
 peerconn_test.go        |  4 ++--
 torrent.go              |  1 +
 webtorrent/client.go    |  4 +++-
 webtorrent/transport.go |  4 ++--
 6 files changed, 24 insertions(+), 13 deletions(-)

diff --git a/client.go b/client.go
index 43a4c46f..98c87171 100644
--- a/client.go
+++ b/client.go
@@ -461,12 +461,17 @@ func (cl *Client) acceptConnections(l net.Listener) {
 	}
 }
 
+func regularConnString(nc net.Conn) string {
+	return fmt.Sprintf("%s-%s", nc.LocalAddr(), nc.RemoteAddr())
+}
+
 func (cl *Client) incomingConnection(nc net.Conn) {
 	defer nc.Close()
 	if tc, ok := nc.(*net.TCPConn); ok {
 		tc.SetLinger(0)
 	}
-	c := cl.newConnection(nc, false, nc.RemoteAddr(), nc.RemoteAddr().Network())
+	c := cl.newConnection(nc, false, nc.RemoteAddr(), nc.RemoteAddr().Network(),
+		regularConnString(nc))
 	c.Discovery = PeerSourceIncoming
 	cl.runReceivedConn(c)
 }
@@ -623,8 +628,10 @@ func (cl *Client) noLongerHalfOpen(t *Torrent, addr string) {
 
 // Performs initiator handshakes and returns a connection. Returns nil *connection if no connection
 // for valid reasons.
-func (cl *Client) handshakesConnection(ctx context.Context, nc net.Conn, t *Torrent, encryptHeader bool, remoteAddr net.Addr, network string) (c *PeerConn, err error) {
-	c = cl.newConnection(nc, true, remoteAddr, network)
+func (cl *Client) handshakesConnection(ctx context.Context, nc net.Conn, t *Torrent, encryptHeader bool, remoteAddr net.Addr,
+	network, connString string,
+) (c *PeerConn, err error) {
+	c = cl.newConnection(nc, true, remoteAddr, network, connString)
 	c.headerEncrypted = encryptHeader
 	ctx, cancel := context.WithTimeout(ctx, cl.config.HandshakesTimeout)
 	defer cancel()
@@ -640,8 +647,7 @@ func (cl *Client) handshakesConnection(ctx context.Context, nc net.Conn, t *Torr
 	return
 }
 
-// Returns nil connection and nil error if no connection could be established
-// for valid reasons.
+// Returns nil connection and nil error if no connection could be established for valid reasons.
 func (cl *Client) establishOutgoingConnEx(t *Torrent, addr net.Addr, obfuscatedHeader bool) (*PeerConn, error) {
 	dialCtx, cancel := context.WithTimeout(context.Background(), func() time.Duration {
 		cl.rLock()
@@ -657,7 +663,7 @@ func (cl *Client) establishOutgoingConnEx(t *Torrent, addr net.Addr, obfuscatedH
 		}
 		return nil, errors.New("dial failed")
 	}
-	c, err := cl.handshakesConnection(context.Background(), nc, t, obfuscatedHeader, addr, dr.Network)
+	c, err := cl.handshakesConnection(context.Background(), nc, t, obfuscatedHeader, addr, dr.Network, regularConnString(nc))
 	if err != nil {
 		nc.Close()
 	}
@@ -1228,7 +1234,7 @@ func (cl *Client) banPeerIP(ip net.IP) {
 	cl.badPeerIPs[ip.String()] = struct{}{}
 }
 
-func (cl *Client) newConnection(nc net.Conn, outgoing bool, remoteAddr net.Addr, network string) (c *PeerConn) {
+func (cl *Client) newConnection(nc net.Conn, outgoing bool, remoteAddr net.Addr, network, connString string) (c *PeerConn) {
 	c = &PeerConn{
 		conn:            nc,
 		outgoing:        outgoing,
@@ -1238,6 +1244,7 @@ func (cl *Client) newConnection(nc net.Conn, outgoing bool, remoteAddr net.Addr,
 		writeBuffer:     new(bytes.Buffer),
 		remoteAddr:      remoteAddr,
 		network:         network,
+		connString:      connString,
 	}
 	c.logger = cl.logger.WithValues(c,
 		log.Debug, // I want messages to default to debug, and can set it here as it's only used by new code
diff --git a/peerconn.go b/peerconn.go
index ee5cdfd9..45ad375e 100644
--- a/peerconn.go
+++ b/peerconn.go
@@ -43,6 +43,7 @@ type PeerConn struct {
 	t *Torrent
 	// The actual Conn, used for closing, and setting socket options.
 	conn       net.Conn
+	connString string
 	outgoing   bool
 	network    string
 	remoteAddr net.Addr
@@ -280,7 +281,7 @@ func (cn *PeerConn) downloadRate() float64 {
 
 func (cn *PeerConn) writeStatus(w io.Writer, t *Torrent) {
 	// \t isn't preserved in <pre> blocks?
-	fmt.Fprintf(w, "%+-55q %s %s-%s\n", cn.PeerID, cn.PeerExtensionBytes, cn.localAddr(), cn.remoteAddr)
+	fmt.Fprintf(w, "%+-55q %s %s\n", cn.PeerID, cn.PeerExtensionBytes, cn.connString)
 	fmt.Fprintf(w, "    last msg: %s, connected: %s, last helpful: %s, itime: %s, etime: %s\n",
 		eventAgeString(cn.lastMessageReceived),
 		eventAgeString(cn.completedHandshake),
diff --git a/peerconn_test.go b/peerconn_test.go
index da7c5bb3..e1d876f9 100644
--- a/peerconn_test.go
+++ b/peerconn_test.go
@@ -23,7 +23,7 @@ func TestSendBitfieldThenHave(t *testing.T) {
 		config: TestingConfig(),
 	}
 	cl.initLogger()
-	c := cl.newConnection(nil, false, nil, "")
+	c := cl.newConnection(nil, false, nil, "", "")
 	c.setTorrent(cl.newTorrent(metainfo.Hash{}, nil))
 	c.t.setInfo(&metainfo.Info{
 		Pieces: make([]byte, metainfo.HashSize*3),
@@ -107,7 +107,7 @@ func BenchmarkConnectionMainReadLoop(b *testing.B) {
 	t.setChunkSize(defaultChunkSize)
 	t._pendingPieces.Set(0, PiecePriorityNormal.BitmapPriority())
 	r, w := net.Pipe()
-	cn := cl.newConnection(r, true, nil, "")
+	cn := cl.newConnection(r, true, nil, "", "")
 	cn.setTorrent(t)
 	mrlErr := make(chan error)
 	msg := pp.Message{
diff --git a/torrent.go b/torrent.go
index 81730ef8..4875bf5b 100644
--- a/torrent.go
+++ b/torrent.go
@@ -1276,6 +1276,7 @@ func (t *Torrent) onWebRtcConn(
 		false,
 		webrtcNetAddr{dcc.Remote},
 		webrtcNetwork,
+		fmt.Sprintf("webrtc offer_id %x", dcc.OfferId),
 	)
 	if err != nil {
 		t.logger.Printf("error in handshaking webrtc connection: %v", err)
diff --git a/webtorrent/client.go b/webtorrent/client.go
index 72c1d046..54ebf264 100644
--- a/webtorrent/client.go
+++ b/webtorrent/client.go
@@ -41,6 +41,7 @@ func binaryToJsonString(b []byte) string {
 
 type DataChannelContext struct {
 	Local, Remote webrtc.SessionDescription
+	OfferId       string
 	LocalOffered  bool
 }
 
@@ -146,7 +147,7 @@ func (c *Client) trackerReadLoop() error {
 		}
 		switch {
 		case ar.Offer != nil:
-			_, answer, err := NewTransportFromOffer(*ar.Offer, c.onConn)
+			_, answer, err := NewTransportFromOffer(*ar.Offer, c.onConn, ar.OfferID)
 			if err != nil {
 				return fmt.Errorf("write AnnounceResponse: %w", err)
 			}
@@ -184,6 +185,7 @@ func (c *Client) trackerReadLoop() error {
 				c.onConn(dc, DataChannelContext{
 					Local:        offer.originalOffer,
 					Remote:       *ar.Answer,
+					OfferId:      ar.OfferID,
 					LocalOffered: true,
 				})
 			})
diff --git a/webtorrent/transport.go b/webtorrent/transport.go
index efaf3157..db2a94c9 100644
--- a/webtorrent/transport.go
+++ b/webtorrent/transport.go
@@ -67,7 +67,7 @@ func NewTransport() (*Transport, webrtc.SessionDescription, error) {
 
 // NewTransportFromOffer creates a transport from a WebRTC offer and and returns a WebRTC answer to
 // be announced.
-func NewTransportFromOffer(offer webrtc.SessionDescription, onOpen onDataChannelOpen) (*Transport, webrtc.SessionDescription, error) {
+func NewTransportFromOffer(offer webrtc.SessionDescription, onOpen onDataChannelOpen, offerId string) (*Transport, webrtc.SessionDescription, error) {
 	peerConnection, err := newPeerConnection()
 	if err != nil {
 		return nil, webrtc.SessionDescription{}, fmt.Errorf("failed to peer connection: %v", err)
@@ -92,7 +92,7 @@ func NewTransportFromOffer(offer webrtc.SessionDescription, onOpen onDataChannel
 		t.dc = d
 		t.lock.Unlock()
 		t.handleOpen(func(dc datachannel.ReadWriteCloser) {
-			onOpen(dc, DataChannelContext{answer, offer, false})
+			onOpen(dc, DataChannelContext{answer, offer, offerId, false})
 		})
 	})
 	err = peerConnection.SetLocalDescription(answer)