From f59e1ad854d28844c4fc97a1ef740dd96d62b773 Mon Sep 17 00:00:00 2001
From: Audrius Butkevicius <audrius.butkevicius@gmail.com>
Date: Sat, 30 Jan 2016 01:52:32 +0000
Subject: [PATCH] Use dialer in relay checks (fixes #2732)

---
 lib/connections/connections_tcp.go |  3 +--
 lib/dialer/internal.go             |  5 ++---
 lib/dialer/public.go               | 18 ++++++++++++++++++
 lib/osutil/osutil.go               | 20 --------------------
 lib/osutil/ping.go                 |  8 +++-----
 5 files changed, 24 insertions(+), 30 deletions(-)

diff --git a/lib/connections/connections_tcp.go b/lib/connections/connections_tcp.go
index 5dce31066..61d872e1b 100644
--- a/lib/connections/connections_tcp.go
+++ b/lib/connections/connections_tcp.go
@@ -14,7 +14,6 @@ import (
 
 	"github.com/syncthing/syncthing/lib/dialer"
 	"github.com/syncthing/syncthing/lib/model"
-	"github.com/syncthing/syncthing/lib/osutil"
 )
 
 func init() {
@@ -72,7 +71,7 @@ func tcpListener(uri *url.URL, tlsCfg *tls.Config, conns chan<- model.Intermedia
 
 		l.Debugln("connect from", conn.RemoteAddr())
 
-		err = osutil.SetTCPOptions(conn.(*net.TCPConn))
+		err = dialer.SetTCPOptions(conn.(*net.TCPConn))
 		if err != nil {
 			l.Infoln(err)
 		}
diff --git a/lib/dialer/internal.go b/lib/dialer/internal.go
index 3948b0e8e..167818738 100644
--- a/lib/dialer/internal.go
+++ b/lib/dialer/internal.go
@@ -17,7 +17,6 @@ import (
 	"golang.org/x/net/proxy"
 
 	"github.com/syncthing/syncthing/lib/logger"
-	"github.com/syncthing/syncthing/lib/osutil"
 )
 
 var (
@@ -55,7 +54,7 @@ func dialWithFallback(proxyDialFunc dialFunc, fallbackDialFunc dialFunc, network
 	if err == nil {
 		l.Debugf("Dialing %s address %s via proxy - success, %s -> %s", network, addr, conn.LocalAddr(), conn.RemoteAddr())
 		if tcpconn, ok := conn.(*net.TCPConn); ok {
-			osutil.SetTCPOptions(tcpconn)
+			SetTCPOptions(tcpconn)
 		}
 		return dialerConn{
 			conn, newDialerAddr(network, addr),
@@ -67,7 +66,7 @@ func dialWithFallback(proxyDialFunc dialFunc, fallbackDialFunc dialFunc, network
 	if err == nil {
 		l.Debugf("Dialing %s address %s via fallback - success, %s -> %s", network, addr, conn.LocalAddr(), conn.RemoteAddr())
 		if tcpconn, ok := conn.(*net.TCPConn); ok {
-			osutil.SetTCPOptions(tcpconn)
+			SetTCPOptions(tcpconn)
 		}
 	} else {
 		l.Debugf("Dialing %s address %s via fallback - error %s", network, addr, err)
diff --git a/lib/dialer/public.go b/lib/dialer/public.go
index 4bf17c5b9..f64ce1969 100644
--- a/lib/dialer/public.go
+++ b/lib/dialer/public.go
@@ -46,3 +46,21 @@ func DialTimeout(network, addr string, timeout time.Duration) (net.Conn, error)
 	}
 	return net.DialTimeout(network, addr, timeout)
 }
+
+// SetTCPOptions sets syncthings default TCP options on a TCP connection
+func SetTCPOptions(conn *net.TCPConn) error {
+	var err error
+	if err = conn.SetLinger(0); err != nil {
+		return err
+	}
+	if err = conn.SetNoDelay(false); err != nil {
+		return err
+	}
+	if err = conn.SetKeepAlivePeriod(60 * time.Second); err != nil {
+		return err
+	}
+	if err = conn.SetKeepAlive(true); err != nil {
+		return err
+	}
+	return nil
+}
diff --git a/lib/osutil/osutil.go b/lib/osutil/osutil.go
index f4e15885a..64802518e 100644
--- a/lib/osutil/osutil.go
+++ b/lib/osutil/osutil.go
@@ -11,12 +11,10 @@ import (
 	"errors"
 	"fmt"
 	"io"
-	"net"
 	"os"
 	"path/filepath"
 	"runtime"
 	"strings"
-	"time"
 
 	"github.com/calmh/du"
 	"github.com/syncthing/syncthing/lib/sync"
@@ -223,21 +221,3 @@ func DiskFreePercentage(path string) (freePct float64, err error) {
 	u, err := du.Get(path)
 	return (float64(u.FreeBytes) / float64(u.TotalBytes)) * 100, err
 }
-
-// SetTCPOptions sets syncthings default TCP options on a TCP connection
-func SetTCPOptions(conn *net.TCPConn) error {
-	var err error
-	if err = conn.SetLinger(0); err != nil {
-		return err
-	}
-	if err = conn.SetNoDelay(false); err != nil {
-		return err
-	}
-	if err = conn.SetKeepAlivePeriod(60 * time.Second); err != nil {
-		return err
-	}
-	if err = conn.SetKeepAlive(true); err != nil {
-		return err
-	}
-	return nil
-}
diff --git a/lib/osutil/ping.go b/lib/osutil/ping.go
index 743da5f71..756037fea 100644
--- a/lib/osutil/ping.go
+++ b/lib/osutil/ping.go
@@ -7,20 +7,18 @@
 package osutil
 
 import (
-	"net"
 	"net/url"
 	"time"
+
+	"github.com/syncthing/syncthing/lib/dialer"
 )
 
 // TCPPing returns the duration required to establish a TCP connection
 // to the given host. ICMP packets require root priviledges, hence why we use
 // tcp.
 func TCPPing(address string) (time.Duration, error) {
-	dialer := net.Dialer{
-		Deadline: time.Now().Add(time.Second),
-	}
 	start := time.Now()
-	conn, err := dialer.Dial("tcp", address)
+	conn, err := dialer.DialTimeout("tcp", address, time.Second)
 	if conn != nil {
 		conn.Close()
 	}