From 5ccc753367d0cd901262236a124f0f015ed33c6e Mon Sep 17 00:00:00 2001
From: Matthias Radestock <matthias.radestock@gmail.com>
Date: Wed, 24 Dec 2014 10:33:37 +0000
Subject: [PATCH] kill stale connections The weave protocol already effectively
 performs heartbeating - FetchAll is performed at regular intervals. Hence we
 can detect stale connections by the lack of receiving any data for
 approximately that interval (we use x2).

We use the same interval to set a time limit on the handshake too, and
any subsequent interactions prior to the connection being fully
established.

Fixes #272.
---
 router/connection.go | 7 ++++++-
 router/consts.go     | 1 +
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/router/connection.go b/router/connection.go
index 9ff2e303..2388a284 100644
--- a/router/connection.go
+++ b/router/connection.go
@@ -285,8 +285,8 @@ func (conn *LocalConnection) handshake(acceptNewPeer bool) error {
 	// ourself. Only when we add this connection to the conn.local
 	// peer will it be visible from multiple go-routines.
 	tcpConn := conn.TCPConn
-	tcpConn.SetKeepAlive(true)
 	tcpConn.SetLinger(0)
+	conn.extendReadDeadline()
 
 	enc := gob.NewEncoder(tcpConn)
 
@@ -428,6 +428,7 @@ func (conn *LocalConnection) receiveTCP(decoder *gob.Decoder, usingPassword bool
 	var err error
 	for {
 		var msg []byte
+		conn.extendReadDeadline()
 		if conn.CheckFatal(decoder.Decode(&msg)) != nil {
 			return
 		}
@@ -501,6 +502,10 @@ func (conn *LocalConnection) receiveTCP(decoder *gob.Decoder, usingPassword bool
 	}
 }
 
+func (conn *LocalConnection) extendReadDeadline() {
+	conn.TCPConn.SetReadDeadline(time.Now().Add(ReadTimeout))
+}
+
 // Heartbeats
 
 // Heartbeating serves two purposes: a) keeping NAT paths alive, and
diff --git a/router/consts.go b/router/consts.go
index ae9fa46b..92245167 100644
--- a/router/consts.go
+++ b/router/consts.go
@@ -22,6 +22,7 @@ const (
 	SlowHeartbeat      = 10 * time.Second
 	FetchAllInterval   = 30 * time.Second
 	FragTestInterval   = 5 * time.Minute
+	ReadTimeout        = 2 * FetchAllInterval
 	PMTUVerifyAttempts = 8
 	PMTUVerifyTimeout  = 10 * time.Millisecond // gets doubled with every attempt
 	MaxDuration        = time.Duration(math.MaxInt64)