From 70c8bb19a7db2f270b2130c62eafb1cabef42ff0 Mon Sep 17 00:00:00 2001
From: Kr328 <39107975+Kr328@users.noreply.github.com>
Date: Sat, 30 Nov 2019 01:58:06 +0800
Subject: [PATCH] fix buffer & dns nil

---
 core/src/main/golang/tun/dnsredirect.go           | 15 ++++++++++++---
 core/src/main/golang/tun/tun.go                   |  6 +++++-
 .../com/github/kr328/clash/service/TunService.kt  |  5 ++++-
 3 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/core/src/main/golang/tun/dnsredirect.go b/core/src/main/golang/tun/dnsredirect.go
index 2133257..3680f02 100644
--- a/core/src/main/golang/tun/dnsredirect.go
+++ b/core/src/main/golang/tun/dnsredirect.go
@@ -4,6 +4,7 @@ import (
 	"net"
 	"time"
 
+	"github.com/Dreamacro/clash/common/pool"
 	"github.com/google/netstack/tcpip/adapters/gonet"
 	"github.com/google/netstack/tcpip/buffer"
 	"github.com/google/netstack/tcpip/stack"
@@ -24,9 +25,11 @@ func NewDnsRedirect(s *stack.Stack) *DnsRedirectEndpoint {
 	result := &DnsRedirectEndpoint{
 		stack:        s,
 		udpForwarder: nil,
-		targetAddr:   &net.UDPAddr{IP: net.ParseIP("8.8.8.8"), Port: 53},
+		targetAddr:   nil,
 	}
 
+	result.SetDefaultTargetAddress()
+
 	result.udpForwarder = udp.NewForwarder(s, func(request *udp.ForwarderRequest) {
 		var wq waiter.Queue
 		ep, err := request.CreateEndpoint(&wq)
@@ -44,7 +47,8 @@ func NewDnsRedirect(s *stack.Stack) *DnsRedirectEndpoint {
 
 		// send
 		go func() {
-			var buffer [128]byte
+			buffer := pool.BufPool.Get().([]byte)
+			defer pool.BufPool.Put(buffer[:cap(buffer)])
 
 			defer targetConn.Close()
 			defer conn.Close()
@@ -66,7 +70,8 @@ func NewDnsRedirect(s *stack.Stack) *DnsRedirectEndpoint {
 
 		// receive
 		go func() {
-			var buffer [128]byte
+			buffer := pool.BufPool.Get().([]byte)
+			defer pool.BufPool.Put(buffer[:cap(buffer)])
 
 			defer targetConn.Close()
 			defer conn.Close()
@@ -90,6 +95,10 @@ func NewDnsRedirect(s *stack.Stack) *DnsRedirectEndpoint {
 	return result
 }
 
+func (d *DnsRedirectEndpoint) SetDefaultTargetAddress() {
+	d.targetAddr = &net.UDPAddr{IP: net.ParseIP(defaultDNS), Port: 53}
+}
+
 func (d *DnsRedirectEndpoint) SetTargetAddress(addr *net.UDPAddr) {
 	d.targetAddr = addr
 }
diff --git a/core/src/main/golang/tun/tun.go b/core/src/main/golang/tun/tun.go
index 923338e..6818abc 100644
--- a/core/src/main/golang/tun/tun.go
+++ b/core/src/main/golang/tun/tun.go
@@ -77,5 +77,9 @@ func SetDNSRedirect(addr *net.UDPAddr) {
 		return
 	}
 
-	instance.dnsRedirect.SetTargetAddress(addr)
+	if addr != nil {
+		instance.dnsRedirect.SetTargetAddress(addr)
+	} else {
+		instance.dnsRedirect.SetDefaultTargetAddress()
+	}
 }
diff --git a/service/src/main/java/com/github/kr328/clash/service/TunService.kt b/service/src/main/java/com/github/kr328/clash/service/TunService.kt
index fae7e29..9b1f2f0 100644
--- a/service/src/main/java/com/github/kr328/clash/service/TunService.kt
+++ b/service/src/main/java/com/github/kr328/clash/service/TunService.kt
@@ -100,7 +100,10 @@ class TunService : VpnService(), IClashEventObserver {
     override fun onProcessEvent(event: ProcessEvent?) {
         when (event) {
             ProcessEvent.STOPPED -> {
-                if (start)
+                val startNow = start
+                start = false
+
+                if (startNow)
                     clash.start()
                 else
                     stopSelf()