From e7ff6a21918a39b717c6ff596d3a3b2cff3f1b7f Mon Sep 17 00:00:00 2001
From: Matthias Radestock <matthias.radestock@gmail.com>
Date: Thu, 5 Nov 2015 19:32:49 +0000
Subject: [PATCH] LocalPeer shouldn't have to know about remote UDP address

...and LocalConnection shouldn't have to remember it
---
 router/connection.go | 32 ++++++++++++++++++--------------
 router/local_peer.go | 13 ++++---------
 router/router.go     |  2 +-
 3 files changed, 23 insertions(+), 24 deletions(-)

diff --git a/router/connection.go b/router/connection.go
index 9f047159..699a12de 100644
--- a/router/connection.go
+++ b/router/connection.go
@@ -40,17 +40,16 @@ type RemoteConnection struct {
 type LocalConnection struct {
 	sync.RWMutex
 	RemoteConnection
-	TCPConn       *net.TCPConn
-	version       byte
-	tcpSender     TCPSender
-	remoteUDPAddr *net.UDPAddr
-	SessionKey    *[32]byte
-	heartbeatTCP  *time.Ticker
-	Router        *Router
-	uid           uint64
-	actionChan    chan<- ConnectionAction
-	finished      <-chan struct{} // closed to signal that actorLoop has finished
-	forwarder     OverlayForwarder
+	TCPConn      *net.TCPConn
+	version      byte
+	tcpSender    TCPSender
+	SessionKey   *[32]byte
+	heartbeatTCP *time.Ticker
+	Router       *Router
+	uid          uint64
+	actionChan   chan<- ConnectionAction
+	finished     <-chan struct{} // closed to signal that actorLoop has finished
+	forwarder    OverlayForwarder
 }
 
 type ConnectionAction func() error
@@ -83,7 +82,7 @@ func (conn *RemoteConnection) ErrorLog(args ...interface{}) {
 
 // Does not return anything. If the connection is successful, it will
 // end up in the local peer's connections map.
-func StartLocalConnection(connRemote *RemoteConnection, tcpConn *net.TCPConn, udpAddr *net.UDPAddr, router *Router, acceptNewPeer bool) {
+func StartLocalConnection(connRemote *RemoteConnection, tcpConn *net.TCPConn, router *Router, acceptNewPeer bool) {
 	if connRemote.local != router.Ourself.Peer {
 		log.Fatal("Attempt to create local connection from a peer which is not ourself")
 	}
@@ -94,7 +93,6 @@ func StartLocalConnection(connRemote *RemoteConnection, tcpConn *net.TCPConn, ud
 		RemoteConnection: *connRemote,
 		Router:           router,
 		TCPConn:          tcpConn,
-		remoteUDPAddr:    udpAddr,
 		uid:              randUint64(),
 		actionChan:       actionChan,
 		finished:         finished}
@@ -192,10 +190,16 @@ func (conn *LocalConnection) run(actionChan <-chan ConnectionAction, finished ch
 
 	conn.Log("connection ready; using protocol version", conn.version)
 
+	var remoteAddr *net.UDPAddr
+	if conn.outbound {
+		tcpAddr := conn.TCPConn.RemoteAddr().(*net.TCPAddr)
+		remoteAddr = &net.UDPAddr{IP: tcpAddr.IP, Port: tcpAddr.Port, Zone: tcpAddr.Zone}
+	}
+
 	params := ForwarderParams{
 		RemotePeer:         conn.remote,
 		LocalIP:            conn.TCPConn.LocalAddr().(*net.TCPAddr).IP,
-		RemoteAddr:         conn.remoteUDPAddr,
+		RemoteAddr:         remoteAddr,
 		ConnUID:            conn.uid,
 		Crypto:             conn.forwarderCrypto(),
 		SendControlMessage: conn.sendOverlayControlMessage,
diff --git a/router/local_peer.go b/router/local_peer.go
index f0047486..80c5abcc 100644
--- a/router/local_peer.go
+++ b/router/local_peer.go
@@ -62,21 +62,16 @@ func (peer *LocalPeer) CreateConnection(peerAddr string, acceptNewPeer bool) err
 	if err := peer.checkConnectionLimit(); err != nil {
 		return err
 	}
-	tcpAddr, tcpErr := net.ResolveTCPAddr("tcp4", peerAddr)
-	udpAddr, udpErr := net.ResolveUDPAddr("udp4", peerAddr)
-	if tcpErr != nil || udpErr != nil {
-		// they really should have the same value, but just in case...
-		if tcpErr == nil {
-			return udpErr
-		}
-		return tcpErr
+	tcpAddr, err := net.ResolveTCPAddr("tcp4", peerAddr)
+	if err != nil {
+		return err
 	}
 	tcpConn, err := net.DialTCP("tcp4", nil, tcpAddr)
 	if err != nil {
 		return err
 	}
 	connRemote := NewRemoteConnection(peer.Peer, nil, tcpConn.RemoteAddr().String(), true, false)
-	StartLocalConnection(connRemote, tcpConn, udpAddr, peer.router, acceptNewPeer)
+	StartLocalConnection(connRemote, tcpConn, peer.router, acceptNewPeer)
 	return nil
 }
 
diff --git a/router/router.go b/router/router.go
index 5e135a6d..7e8cf346 100644
--- a/router/router.go
+++ b/router/router.go
@@ -171,7 +171,7 @@ func (router *Router) acceptTCP(tcpConn *net.TCPConn) {
 	remoteAddrStr := tcpConn.RemoteAddr().String()
 	log.Printf("->[%s] connection accepted", remoteAddrStr)
 	connRemote := NewRemoteConnection(router.Ourself.Peer, nil, remoteAddrStr, false, false)
-	StartLocalConnection(connRemote, tcpConn, nil, router, true)
+	StartLocalConnection(connRemote, tcpConn, router, true)
 }
 
 func (router *Router) handleForwardedPacket(key ForwardPacketKey) FlowOp {