From a060407db1b89060567c8e7974db9552700d9701 Mon Sep 17 00:00:00 2001
From: Frank Denis <github@pureftpd.org>
Date: Tue, 4 Jun 2019 01:37:59 +0200
Subject: [PATCH] Use a different address than 255.255.255.0 for netprobes

Windows doesn't seem to like this address.

Also default to the fallback resolver IP if there is one and
no netprobe_address option in the configuration file.

Fix netprobe_timeout = -1 by the way
---
 dnscrypt-proxy/config.go                   | 12 +++++++++---
 dnscrypt-proxy/example-dnscrypt-proxy.toml |  2 +-
 dnscrypt-proxy/netprobe_windows.go         |  2 +-
 3 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/dnscrypt-proxy/config.go b/dnscrypt-proxy/config.go
index 7872f206..0ec4192b 100644
--- a/dnscrypt-proxy/config.go
+++ b/dnscrypt-proxy/config.go
@@ -21,7 +21,8 @@ import (
 )
 
 const (
-	MaxTimeout = 3600
+	MaxTimeout             = 3600
+	DefaultNetprobeAddress = "9.9.9.9:53"
 )
 
 type Config struct {
@@ -112,7 +113,6 @@ func newConfig() Config {
 		LogMaxBackups:            1,
 		TLSDisableSessionTickets: false,
 		TLSCipherSuite:           nil,
-		NetprobeAddress:          "255.255.255.0:53",
 		NetprobeTimeout:          60,
 		OfflineMode:              false,
 		RefusedCodeInResponses:   false,
@@ -425,7 +425,13 @@ func ConfigLoad(proxy *Proxy, svcFlag *string) error {
 			netprobeTimeout = *netprobeTimeoutOverride
 		}
 	})
-	NetProbe(config.NetprobeAddress, netprobeTimeout)
+	netprobeAddress := DefaultNetprobeAddress
+	if len(config.NetprobeAddress) > 0 {
+		netprobeAddress = config.NetprobeAddress
+	} else if len(config.FallbackResolver) > 0 {
+		netprobeAddress = config.FallbackResolver
+	}
+	NetProbe(netprobeAddress, netprobeTimeout)
 	if !config.OfflineMode {
 		if err := config.loadSources(proxy); err != nil {
 			return err
diff --git a/dnscrypt-proxy/example-dnscrypt-proxy.toml b/dnscrypt-proxy/example-dnscrypt-proxy.toml
index b67940af..6fdfe350 100644
--- a/dnscrypt-proxy/example-dnscrypt-proxy.toml
+++ b/dnscrypt-proxy/example-dnscrypt-proxy.toml
@@ -217,7 +217,7 @@ netprobe_timeout = 60
 ## On other operating systems, the connection will be initialized
 ## but nothing will be sent at all.
 
-netprobe_address = "255.255.255.0:53"
+netprobe_address = "9.9.9.9:53"
 
 
 ## Offline mode - Do not use any remote encrypted servers.
diff --git a/dnscrypt-proxy/netprobe_windows.go b/dnscrypt-proxy/netprobe_windows.go
index 7f767ad9..ae22d944 100644
--- a/dnscrypt-proxy/netprobe_windows.go
+++ b/dnscrypt-proxy/netprobe_windows.go
@@ -9,7 +9,7 @@ import (
 )
 
 func NetProbe(address string, timeout int) error {
-	if len(address) <= 0 || timeout <= 0 {
+	if len(address) <= 0 || timeout == 0 {
 		return nil
 	}
 	remoteUDPAddr, err := net.ResolveUDPAddr("udp", address)