From 99525ebf85891fbcfa3f2c5599bcc4816e581d35 Mon Sep 17 00:00:00 2001
From: Matthias Radestock <matthias.radestock@gmail.com>
Date: Wed, 21 Jan 2015 21:23:59 +0000
Subject: [PATCH] refactor: LocalConnection.CheckFatal be gone! use Shutdown
 instead, which is in the Connection interface, thus further reducing
 dependency on LocalConnection.

---
 router/connection.go | 17 ++++-------------
 router/crypto.go     |  6 ++++--
 router/forwarder.go  |  2 +-
 router/local_peer.go | 12 ++++++------
 router/router.go     |  2 +-
 5 files changed, 16 insertions(+), 23 deletions(-)

diff --git a/router/connection.go b/router/connection.go
index d07d2548..8ccaaa11 100644
--- a/router/connection.go
+++ b/router/connection.go
@@ -149,17 +149,6 @@ func (conn *LocalConnection) Established() bool {
 	return conn.established
 }
 
-// Called by the forwarder processes in a few places (including
-// crypto), but the connection TCP receiver process, and by the local
-// peer actor process. Do not call this from the connection's actor
-// process itself.
-func (conn *LocalConnection) CheckFatal(err error) error {
-	if err != nil {
-		conn.Shutdown(err)
-	}
-	return err
-}
-
 // Called by forwarder processes, read in Forward (by sniffer and udp
 // listener process in router).
 func (conn *LocalConnection) setEffectivePMTU(pmtu int) {
@@ -538,7 +527,8 @@ func (conn *LocalConnection) receiveTCP(decoder *gob.Decoder) {
 	for {
 		var msg []byte
 		conn.extendReadDeadline()
-		if conn.CheckFatal(decoder.Decode(&msg)) != nil {
+		if err = decoder.Decode(&msg); err != nil {
+			conn.Shutdown(err)
 			return
 		}
 		msg, err = receiver.Decode(msg)
@@ -597,7 +587,8 @@ func (conn *LocalConnection) receiveTCP(decoder *gob.Decoder) {
 				conn.SendProtocolMsg(ProtocolMsg{ProtocolFetchAll, nil})
 				continue
 			}
-			if conn.CheckFatal(err) != nil {
+			if err != nil {
+				conn.Shutdown(err)
 				return
 			}
 			if len(newUpdate) != 0 {
diff --git a/router/crypto.go b/router/crypto.go
index 8b57722c..f019502e 100644
--- a/router/crypto.go
+++ b/router/crypto.go
@@ -204,7 +204,8 @@ func (ne *NaClEncryptor) Bytes() []byte {
 	nonce := ne.nonce
 	if nonce == nil {
 		freshNonce, encodedNonce, err := EncodeNonce(ne.df)
-		if err = ne.conn.CheckFatal(err); err != nil {
+		if err != nil {
+			ne.conn.Shutdown(err)
 			return []byte{}
 		}
 		ne.conn.SendProtocolMsg(ProtocolMsg{ProtocolNonce, encodedNonce})
@@ -222,7 +223,8 @@ func (ne *NaClEncryptor) Bytes() []byte {
 		ne.nonce = <-ne.nonceChan
 	} else if offset == 1<<14 { // half way through range, send new nonce
 		nonce, encodedNonce, err := EncodeNonce(ne.df)
-		if err = ne.conn.CheckFatal(err); err != nil {
+		if err != nil {
+			ne.conn.Shutdown(err)
 			return []byte{}
 		}
 		ne.nonceChan <- nonce
diff --git a/router/forwarder.go b/router/forwarder.go
index 2e4f0905..d33cd701 100644
--- a/router/forwarder.go
+++ b/router/forwarder.go
@@ -349,7 +349,7 @@ func (fwd *Forwarder) flush() {
 		} else if PosixError(err) == syscall.ENOBUFS {
 			// TODO handle this better
 		} else {
-			fwd.conn.CheckFatal(err)
+			fwd.conn.Shutdown(err)
 		}
 	}
 }
diff --git a/router/local_peer.go b/router/local_peer.go
index 33c49de3..f7b707c6 100644
--- a/router/local_peer.go
+++ b/router/local_peer.go
@@ -192,21 +192,21 @@ func (peer *LocalPeer) handleAddConnection(conn *LocalConnection) {
 		dupConnLocal := dupConn.(*LocalConnection)
 		switch conn.BreakTie(dupConnLocal) {
 		case TieBreakWon:
-			dupConnLocal.CheckFatal(dupErr)
+			dupConn.Shutdown(dupErr)
 			peer.handleDeleteConnection(dupConnLocal)
 		case TieBreakLost:
-			conn.CheckFatal(dupErr)
+			conn.Shutdown(dupErr)
 			return
 		case TieBreakTied:
 			// oh good grief. Sod it, just kill both of them.
-			conn.CheckFatal(dupErr)
-			dupConnLocal.CheckFatal(dupErr)
+			conn.Shutdown(dupErr)
+			dupConn.Shutdown(dupErr)
 			peer.handleDeleteConnection(dupConnLocal)
 			return
 		}
 	}
 	if err := peer.checkConnectionLimit(); err != nil {
-		conn.CheckFatal(err)
+		conn.Shutdown(err)
 		return
 	}
 	peer.addConnection(conn)
@@ -239,7 +239,7 @@ func (peer *LocalPeer) handleConnectionEstablished(conn *LocalConnection) {
 		log.Fatal("Peer informed of active connection where peer is not the source of connection")
 	}
 	if dupConn, found := peer.connections[conn.Remote().Name]; !found || conn != dupConn {
-		conn.CheckFatal(fmt.Errorf("Cannot set unknown connection active"))
+		conn.Shutdown(fmt.Errorf("Cannot set unknown connection active"))
 		return
 	}
 	peer.connectionEstablished(conn)
diff --git a/router/router.go b/router/router.go
index bc6170b3..65865578 100644
--- a/router/router.go
+++ b/router/router.go
@@ -252,7 +252,7 @@ func (router *Router) udpReader(conn *net.UDPConn, po PacketSink) {
 		err = relayConn.Decryptor.IterateFrames(handleUDPPacket, udpPacket)
 		if pde, ok := err.(PacketDecodingError); ok {
 			if pde.Fatal {
-				relayConn.CheckFatal(pde)
+				relayConn.Shutdown(pde)
 			} else {
 				relayConn.log(pde.Error())
 			}