From 11fbeaafa145e37cde7a6dac4dce6be0e6ce1605 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E6=9E=97=E5=BF=97=E5=AE=87?= <evanlinjin@pm.me>
Date: Fri, 10 May 2019 01:04:27 +1200
Subject: [PATCH] made modifications to channel ID thread-safe.

---
 .gitignore                    |  3 ++-
 pkg/messaging/channel.go      | 23 ++++++++++++++++++++---
 pkg/messaging/channel_test.go |  4 ++--
 pkg/messaging/client.go       | 10 +++++-----
 4 files changed, 29 insertions(+), 11 deletions(-)

diff --git a/.gitignore b/.gitignore
index 4cd5ed0cb7..3abd13c0f7 100644
--- a/.gitignore
+++ b/.gitignore
@@ -27,4 +27,5 @@ pkg/node/foo/
 /*-node
 /*-cli
 /*.json
-/*.sh
\ No newline at end of file
+/*.sh
+/*.log
\ No newline at end of file
diff --git a/pkg/messaging/channel.go b/pkg/messaging/channel.go
index 574633225e..1256ed4485 100644
--- a/pkg/messaging/channel.go
+++ b/pkg/messaging/channel.go
@@ -16,7 +16,9 @@ import (
 )
 
 type channel struct {
-	ID       byte
+	id   byte // This is to be changed.
+	idMx sync.RWMutex
+
 	remotePK cipher.PubKey
 	link     *Link
 	buf      *bytes.Buffer
@@ -59,6 +61,21 @@ func newChannel(initiator bool, secKey cipher.SecKey, remote cipher.PubKey, link
 	}, nil
 }
 
+// ID obtains the channel's id.
+func (c *channel) ID() byte {
+	c.idMx.RLock()
+	id := c.id
+	c.idMx.RUnlock()
+	return id
+}
+
+// SetID set's the channel's id.
+func (c *channel) SetID(id byte) {
+	c.idMx.Lock()
+	c.id = id
+	c.idMx.Unlock()
+}
+
 // Edges returns the public keys of the channel's edge nodes
 func (c *channel) Edges() [2]cipher.PubKey {
 	return transport.SortPubKeys(c.link.Local(), c.remotePK)
@@ -122,7 +139,7 @@ func (c *channel) Write(p []byte) (n int, err error) {
 	done := make(chan struct{}, 1)
 	defer close(done)
 	go func() {
-		n, err = c.link.Send(c.ID, buf)
+		n, err = c.link.Send(c.ID(), buf)
 		n = n - (len(data) - len(p) + 2)
 		select {
 		case done <- struct{}{}:
@@ -143,7 +160,7 @@ func (c *channel) Close() error {
 		return ErrChannelClosed
 	}
 
-	if _, err := c.link.SendCloseChannel(c.ID); err != nil {
+	if _, err := c.link.SendCloseChannel(c.ID()); err != nil {
 		return err
 	}
 
diff --git a/pkg/messaging/channel_test.go b/pkg/messaging/channel_test.go
index d8d7908b16..16b486610d 100644
--- a/pkg/messaging/channel_test.go
+++ b/pkg/messaging/channel_test.go
@@ -81,7 +81,7 @@ func TestChannelWrite(t *testing.T) {
 
 	c, err := newChannel(true, sk, remotePK, l)
 	require.NoError(t, err)
-	c.ID = 10
+	c.SetID(10)
 
 	rn := handshakeChannel(t, c, remotePK, remoteSK)
 
@@ -118,7 +118,7 @@ func TestChannelClose(t *testing.T) {
 
 	c, err := newChannel(true, sk, remotePK, l)
 	require.NoError(t, err)
-	c.ID = 10
+	c.SetID(10)
 
 	handshakeChannel(t, c, remotePK, remoteSK)
 
diff --git a/pkg/messaging/client.go b/pkg/messaging/client.go
index 0ec5be2eac..c81abc44ad 100644
--- a/pkg/messaging/client.go
+++ b/pkg/messaging/client.go
@@ -179,7 +179,7 @@ func (c *Client) Dial(ctx context.Context, remote cipher.PubKey) (transport.Tran
 		return nil, ctx.Err()
 	}
 
-	c.Logger.Infof("Opened new channel local ID %d, remote ID %d with %s", localID, channel.ID, remote)
+	c.Logger.Infof("Opened new channel local ID %d, remote ID %d with %s", localID, channel.ID(), remote) // TODO: race condition
 	return channel, nil
 }
 
@@ -314,10 +314,10 @@ func (c *Client) onData(l *Link, frameType FrameType, body []byte) error {
 	switch frameType {
 	case FrameTypeCloseChannel:
 		clientLink.chans.remove(channelID)
-		_, sendErr = l.SendChannelClosed(channel.ID)
+		_, sendErr = l.SendChannelClosed(channel.ID())
 		c.Logger.Debugf("Closed channel ID %d", channelID)
 	case FrameTypeChannelOpened:
-		channel.ID = body[1]
+		channel.SetID(body[1])
 		if err := channel.ProcessMessage(body[2:]); err != nil {
 			sendErr = fmt.Errorf("noise handshake: %s", err)
 		}
@@ -327,7 +327,7 @@ func (c *Client) onData(l *Link, frameType FrameType, body []byte) error {
 		default:
 		}
 	case FrameTypeChannelClosed:
-		channel.ID = body[0]
+		channel.SetID(body[0])
 		select {
 		case channel.waitChan <- false:
 		case channel.closeChan <- struct{}{}:
@@ -390,7 +390,7 @@ func (c *Client) openChannel(rID byte, remotePK []byte, noiseMsg []byte, chanLin
 	}
 
 	channel, err := newChannel(false, c.secKey, pubKey, chanLink.link)
-	channel.ID = rID
+	channel.SetID(rID)
 	if err != nil {
 		err = fmt.Errorf("noise setup: %s", err)
 		return