From 6c4791480ed31e66acc5572f237d030998f7a548 Mon Sep 17 00:00:00 2001
From: yaling888 <73897884+yaling888@users.noreply.github.com>
Date: Tue, 19 Apr 2022 17:46:13 +0800
Subject: [PATCH] Chore: IpToAddr

---
 common/nnip/netip.go                          | 53 +++++++++++++++++++
 component/fakeip/pool.go                      | 40 ++------------
 component/fakeip/pool_test.go                 |  8 ++-
 dns/enhancer.go                               | 11 ++--
 dns/middleware.go                             |  3 +-
 dns/util.go                                   | 17 ------
 .../tun/ipstack/commons/router_windows.go     |  5 +-
 listener/tun/ipstack/gvisor/handler.go        | 24 +++++----
 listener/tun/ipstack/system/mars/mars.go      |  4 +-
 listener/tun/ipstack/system/mars/nat/nat.go   | 36 ++++++-------
 listener/tun/ipstack/system/mars/nat/udp.go   |  8 ++-
 listener/tun/ipstack/system/mars/tcpip/ip.go  |  6 ---
 listener/tun/ipstack/system/stack.go          | 37 ++++++++-----
 listener/tun/tun_adapter.go                   |  3 +-
 14 files changed, 136 insertions(+), 119 deletions(-)
 create mode 100644 common/nnip/netip.go

diff --git a/common/nnip/netip.go b/common/nnip/netip.go
new file mode 100644
index 00000000..e4566138
--- /dev/null
+++ b/common/nnip/netip.go
@@ -0,0 +1,53 @@
+package nnip
+
+import (
+	"encoding/binary"
+	"net"
+	"net/netip"
+)
+
+// IpToAddr converts the net.IP to netip.Addr.
+// If slice's length is not 4 or 16, IpToAddr returns netip.Addr{}
+func IpToAddr(slice net.IP) netip.Addr {
+	ip := slice
+	if len(ip) != 4 {
+		if ip = slice.To4(); ip == nil {
+			ip = slice
+		}
+	}
+
+	if addr, ok := netip.AddrFromSlice(ip); ok {
+		return addr
+	}
+	return netip.Addr{}
+}
+
+// UnMasked returns p's last IP address.
+// If p is invalid, UnMasked returns netip.Addr{}
+func UnMasked(p netip.Prefix) netip.Addr {
+	if !p.IsValid() {
+		return netip.Addr{}
+	}
+
+	buf := p.Addr().As16()
+
+	hi := binary.BigEndian.Uint64(buf[:8])
+	lo := binary.BigEndian.Uint64(buf[8:])
+
+	bits := p.Bits()
+	if bits <= 32 {
+		bits += 96
+	}
+
+	hi = hi | ^uint64(0)>>bits
+	lo = lo | ^(^uint64(0) << (128 - bits))
+
+	binary.BigEndian.PutUint64(buf[:8], hi)
+	binary.BigEndian.PutUint64(buf[8:], lo)
+
+	addr := netip.AddrFrom16(buf)
+	if p.Addr().Is4() {
+		return addr.Unmap()
+	}
+	return addr
+}
diff --git a/component/fakeip/pool.go b/component/fakeip/pool.go
index 57613a48..0137f705 100644
--- a/component/fakeip/pool.go
+++ b/component/fakeip/pool.go
@@ -1,12 +1,11 @@
 package fakeip
 
 import (
-	"encoding/binary"
 	"errors"
-	"math/bits"
 	"net/netip"
 	"sync"
 
+	"github.com/Dreamacro/clash/common/nnip"
 	"github.com/Dreamacro/clash/component/profile/cachefile"
 	"github.com/Dreamacro/clash/component/trie"
 )
@@ -16,11 +15,6 @@ const (
 	cycleKey  = "key-cycle-fake-ip"
 )
 
-type uint128 struct {
-	hi uint64
-	lo uint64
-}
-
 type store interface {
 	GetByHost(host string) (netip.Addr, bool)
 	PutByHost(host string, ip netip.Addr)
@@ -122,7 +116,7 @@ func (p *Pool) FlushFakeIP() error {
 	err := p.store.FlushFakeIP()
 	if err == nil {
 		p.cycle = false
-		p.offset = p.first
+		p.offset = p.first.Prev()
 	}
 	return err
 }
@@ -173,10 +167,10 @@ func New(options Options) (*Pool, error) {
 		hostAddr = options.IPNet.Masked().Addr()
 		gateway  = hostAddr.Next()
 		first    = gateway.Next().Next()
-		last     = add(hostAddr, 1<<uint64(hostAddr.BitLen()-options.IPNet.Bits())-1)
+		last     = nnip.UnMasked(*options.IPNet)
 	)
 
-	if !options.IPNet.IsValid() || !first.Less(last) || !options.IPNet.Contains(last) {
+	if !options.IPNet.IsValid() || !first.IsValid() || !first.Less(last) {
 		return nil, errors.New("ipnet don't have valid ip")
 	}
 
@@ -201,29 +195,3 @@ func New(options Options) (*Pool, error) {
 
 	return pool, nil
 }
-
-// add returns addr + n.
-func add(addr netip.Addr, n uint64) netip.Addr {
-	buf := addr.As16()
-
-	u := uint128{
-		binary.BigEndian.Uint64(buf[:8]),
-		binary.BigEndian.Uint64(buf[8:]),
-	}
-
-	lo, carry := bits.Add64(u.lo, n, 0)
-
-	u.hi = u.hi + carry
-	u.lo = lo
-
-	binary.BigEndian.PutUint64(buf[:8], u.hi)
-	binary.BigEndian.PutUint64(buf[8:], u.lo)
-
-	a := netip.AddrFrom16(buf)
-
-	if addr.Is4() {
-		return a.Unmap()
-	}
-
-	return a
-}
diff --git a/component/fakeip/pool_test.go b/component/fakeip/pool_test.go
index 198df4d5..1f6b3f09 100644
--- a/component/fakeip/pool_test.go
+++ b/component/fakeip/pool_test.go
@@ -240,13 +240,15 @@ func TestPool_FlushFileCache(t *testing.T) {
 		err = pool.FlushFakeIP()
 		assert.Nil(t, err)
 
-		baz := pool.Lookup("foo.com")
 		next := pool.Lookup("baz.com")
+		baz := pool.Lookup("foo.com")
 		nero := pool.Lookup("foo.com")
 
 		assert.True(t, foo == fox)
+		assert.True(t, foo == next)
 		assert.False(t, foo == baz)
 		assert.True(t, bar == bax)
+		assert.True(t, bar == baz)
 		assert.False(t, bar == next)
 		assert.True(t, baz == nero)
 	}
@@ -267,13 +269,15 @@ func TestPool_FlushMemoryCache(t *testing.T) {
 	err := pool.FlushFakeIP()
 	assert.Nil(t, err)
 
-	baz := pool.Lookup("foo.com")
 	next := pool.Lookup("baz.com")
+	baz := pool.Lookup("foo.com")
 	nero := pool.Lookup("foo.com")
 
 	assert.True(t, foo == fox)
+	assert.True(t, foo == next)
 	assert.False(t, foo == baz)
 	assert.True(t, bar == bax)
+	assert.True(t, bar == baz)
 	assert.False(t, bar == next)
 	assert.True(t, baz == nero)
 }
diff --git a/dns/enhancer.go b/dns/enhancer.go
index ff654765..95703b9b 100644
--- a/dns/enhancer.go
+++ b/dns/enhancer.go
@@ -5,6 +5,7 @@ import (
 	"net/netip"
 
 	"github.com/Dreamacro/clash/common/cache"
+	"github.com/Dreamacro/clash/common/nnip"
 	"github.com/Dreamacro/clash/component/fakeip"
 	C "github.com/Dreamacro/clash/constant"
 )
@@ -29,7 +30,7 @@ func (h *ResolverEnhancer) IsExistFakeIP(ip net.IP) bool {
 	}
 
 	if pool := h.fakePool; pool != nil {
-		return pool.Exist(ipToAddr(ip))
+		return pool.Exist(nnip.IpToAddr(ip))
 	}
 
 	return false
@@ -40,7 +41,7 @@ func (h *ResolverEnhancer) IsFakeIP(ip net.IP) bool {
 		return false
 	}
 
-	addr := ipToAddr(ip)
+	addr := nnip.IpToAddr(ip)
 
 	if pool := h.fakePool; pool != nil {
 		return pool.IPNet().Contains(addr) && addr != pool.Gateway() && addr != pool.Broadcast()
@@ -55,14 +56,14 @@ func (h *ResolverEnhancer) IsFakeBroadcastIP(ip net.IP) bool {
 	}
 
 	if pool := h.fakePool; pool != nil {
-		return pool.Broadcast() == ipToAddr(ip)
+		return pool.Broadcast() == nnip.IpToAddr(ip)
 	}
 
 	return false
 }
 
 func (h *ResolverEnhancer) FindHostByIP(ip net.IP) (string, bool) {
-	addr := ipToAddr(ip)
+	addr := nnip.IpToAddr(ip)
 	if pool := h.fakePool; pool != nil {
 		if host, existed := pool.LookBack(addr); existed {
 			return host, true
@@ -80,7 +81,7 @@ func (h *ResolverEnhancer) FindHostByIP(ip net.IP) (string, bool) {
 
 func (h *ResolverEnhancer) InsertHostByIP(ip net.IP, host string) {
 	if mapping := h.mapping; mapping != nil {
-		h.mapping.Set(ipToAddr(ip), host)
+		h.mapping.Set(nnip.IpToAddr(ip), host)
 	}
 }
 
diff --git a/dns/middleware.go b/dns/middleware.go
index 6ee893c5..e227e588 100644
--- a/dns/middleware.go
+++ b/dns/middleware.go
@@ -7,6 +7,7 @@ import (
 	"time"
 
 	"github.com/Dreamacro/clash/common/cache"
+	"github.com/Dreamacro/clash/common/nnip"
 	"github.com/Dreamacro/clash/component/fakeip"
 	"github.com/Dreamacro/clash/component/trie"
 	C "github.com/Dreamacro/clash/constant"
@@ -101,7 +102,7 @@ func withMapping(mapping *cache.LruCache[netip.Addr, string]) middleware {
 					continue
 				}
 
-				mapping.SetWithExpire(ipToAddr(ip), host, time.Now().Add(time.Second*time.Duration(ttl)))
+				mapping.SetWithExpire(nnip.IpToAddr(ip), host, time.Now().Add(time.Second*time.Duration(ttl)))
 			}
 
 			return msg, nil
diff --git a/dns/util.go b/dns/util.go
index e66d1ace..4b4fdbb3 100644
--- a/dns/util.go
+++ b/dns/util.go
@@ -5,7 +5,6 @@ import (
 	"crypto/tls"
 	"fmt"
 	"net"
-	"net/netip"
 	"time"
 
 	"github.com/Dreamacro/clash/common/cache"
@@ -115,22 +114,6 @@ func msgToIP(msg *D.Msg) []net.IP {
 	return ips
 }
 
-func ipToAddr(ip net.IP) netip.Addr {
-	if ip == nil {
-		return netip.Addr{}
-	}
-
-	l := len(ip)
-
-	if l == 4 {
-		return netip.AddrFrom4(*(*[4]byte)(ip))
-	} else if l == 16 {
-		return netip.AddrFrom16(*(*[16]byte)(ip))
-	} else {
-		return netip.Addr{}
-	}
-}
-
 type wrapPacketConn struct {
 	net.PacketConn
 	rAddr net.Addr
diff --git a/listener/tun/ipstack/commons/router_windows.go b/listener/tun/ipstack/commons/router_windows.go
index 4599f999..e6fe8d5a 100644
--- a/listener/tun/ipstack/commons/router_windows.go
+++ b/listener/tun/ipstack/commons/router_windows.go
@@ -6,6 +6,7 @@ import (
 	"net/netip"
 	"time"
 
+	"github.com/Dreamacro/clash/common/nnip"
 	"github.com/Dreamacro/clash/listener/tun/device"
 	"github.com/Dreamacro/clash/listener/tun/device/tun"
 	"github.com/Dreamacro/clash/log"
@@ -226,7 +227,7 @@ func cleanupAddressesOnDisconnectedInterfaces(family winipcfg.AddressFamily, add
 			continue
 		}
 		for address := iface.FirstUnicastAddress; address != nil; address = address.Next {
-			if ip, _ := netip.AddrFromSlice(address.Address.IP()); addrHash[ip] {
+			if ip := nnip.IpToAddr(address.Address.IP()); addrHash[ip] {
 				prefix := netip.PrefixFrom(ip, int(address.OnLinkPrefixLength))
 				log.Infoln("[TUN] cleaning up stale address %s from interface ‘%s’", prefix.String(), iface.FriendlyName())
 				_ = iface.LUID.DeleteIPAddress(prefix)
@@ -260,7 +261,7 @@ func getAutoDetectInterfaceByFamily(family winipcfg.AddressFamily) (string, erro
 		}
 
 		for gatewayAddress := iface.FirstGatewayAddress; gatewayAddress != nil; gatewayAddress = gatewayAddress.Next {
-			nextHop, _ := netip.AddrFromSlice(gatewayAddress.Address.IP())
+			nextHop := nnip.IpToAddr(gatewayAddress.Address.IP())
 
 			if _, err = iface.LUID.Route(destination, nextHop); err == nil {
 				return ifname, nil
diff --git a/listener/tun/ipstack/gvisor/handler.go b/listener/tun/ipstack/gvisor/handler.go
index 78f456db..8c43a64d 100644
--- a/listener/tun/ipstack/gvisor/handler.go
+++ b/listener/tun/ipstack/gvisor/handler.go
@@ -7,6 +7,7 @@ import (
 	"time"
 
 	"github.com/Dreamacro/clash/adapter/inbound"
+	"github.com/Dreamacro/clash/common/nnip"
 	"github.com/Dreamacro/clash/common/pool"
 	C "github.com/Dreamacro/clash/constant"
 	D "github.com/Dreamacro/clash/listener/tun/ipstack/commons"
@@ -33,20 +34,22 @@ func (gh *GVHandler) HandleTCP(tunConn adapter.TCPConn) {
 		Zone: "",
 	}
 
-	addrIp, _ := netip.AddrFromSlice(rAddr.IP)
-	addrPort := netip.AddrPortFrom(addrIp, id.LocalPort)
+	addrPort := netip.AddrPortFrom(nnip.IpToAddr(rAddr.IP), id.LocalPort)
 
 	if D.ShouldHijackDns(gh.DNSAdds, addrPort) {
 		go func() {
 			log.Debugln("[TUN] hijack dns tcp: %s", addrPort.String())
 
-			defer tunConn.Close()
-
 			buf := pool.Get(pool.UDPBufferSize)
-			defer pool.Put(buf)
+			defer func() {
+				_ = pool.Put(buf)
+				_ = tunConn.Close()
+			}()
 
 			for {
-				tunConn.SetReadDeadline(time.Now().Add(D.DefaultDnsReadTimeout))
+				if tunConn.SetReadDeadline(time.Now().Add(D.DefaultDnsReadTimeout)) != nil {
+					break
+				}
 
 				length := uint16(0)
 				if err := binary.Read(tunConn, binary.BigEndian, &length); err != nil {
@@ -86,8 +89,7 @@ func (gh *GVHandler) HandleUDP(tunConn adapter.UDPConn) {
 		Zone: "",
 	}
 
-	addrIp, _ := netip.AddrFromSlice(rAddr.IP)
-	addrPort := netip.AddrPortFrom(addrIp, id.LocalPort)
+	addrPort := netip.AddrPortFrom(nnip.IpToAddr(rAddr.IP), id.LocalPort)
 	target := socks5.ParseAddrToSocksAddr(rAddr)
 
 	go func() {
@@ -96,7 +98,7 @@ func (gh *GVHandler) HandleUDP(tunConn adapter.UDPConn) {
 
 			n, addr, err := tunConn.ReadFrom(buf)
 			if err != nil {
-				pool.Put(buf)
+				_ = pool.Put(buf)
 				break
 			}
 
@@ -104,7 +106,9 @@ func (gh *GVHandler) HandleUDP(tunConn adapter.UDPConn) {
 
 			if D.ShouldHijackDns(gh.DNSAdds, addrPort) {
 				go func() {
-					defer pool.Put(buf)
+					defer func() {
+						_ = pool.Put(buf)
+					}()
 
 					msg, err1 := D.RelayDnsPacket(payload)
 					if err1 != nil {
diff --git a/listener/tun/ipstack/system/mars/mars.go b/listener/tun/ipstack/system/mars/mars.go
index ffc38bf7..e150437e 100644
--- a/listener/tun/ipstack/system/mars/mars.go
+++ b/listener/tun/ipstack/system/mars/mars.go
@@ -13,8 +13,8 @@ type StackListener struct {
 	udp    *nat.UDP
 }
 
-func StartListener(device io.ReadWriteCloser, gateway netip.Addr, portal netip.Addr) (*StackListener, error) {
-	tcp, udp, err := nat.Start(device, gateway, portal)
+func StartListener(device io.ReadWriteCloser, gateway, portal, broadcast netip.Addr) (*StackListener, error) {
+	tcp, udp, err := nat.Start(device, gateway, portal, broadcast)
 	if err != nil {
 		return nil, err
 	}
diff --git a/listener/tun/ipstack/system/mars/nat/nat.go b/listener/tun/ipstack/system/mars/nat/nat.go
index 6feebbef..9f6f57d2 100644
--- a/listener/tun/ipstack/system/mars/nat/nat.go
+++ b/listener/tun/ipstack/system/mars/nat/nat.go
@@ -9,11 +9,7 @@ import (
 	"github.com/Dreamacro/clash/listener/tun/ipstack/system/mars/tcpip"
 )
 
-func Start(
-	device io.ReadWriter,
-	gateway netip.Addr,
-	portal netip.Addr,
-) (*TCP, *UDP, error) {
+func Start(device io.ReadWriter, gateway, portal, broadcast netip.Addr) (*TCP, *UDP, error) {
 	if !portal.Is4() || !gateway.Is4() {
 		return nil, nil, net.InvalidAddrError("only ipv4 supported")
 	}
@@ -37,8 +33,10 @@ func Start(
 	gatewayPort := uint16(listener.Addr().(*net.TCPAddr).Port)
 
 	go func() {
-		defer tcp.Close()
-		defer udp.Close()
+		defer func() {
+			_ = tcp.Close()
+			_ = udp.Close()
+		}()
 
 		buf := make([]byte, pool.RelayBufferSize)
 
@@ -72,7 +70,7 @@ func Start(
 					continue
 				}
 
-				if ipv4.Offset() != 0 {
+				if ipv4.FragmentOffset() != 0 {
 					continue
 				}
 
@@ -92,6 +90,12 @@ func Start(
 				continue
 			}
 
+			destinationIP := ip.DestinationIP()
+
+			if !destinationIP.IsGlobalUnicast() || destinationIP == broadcast {
+				continue
+			}
+
 			switch ip.Protocol() {
 			case tcpip.TCP:
 				t := tcpip.TCPPacket(ip.Payload())
@@ -99,7 +103,7 @@ func Start(
 					continue
 				}
 
-				if ip.DestinationIP() == portal {
+				if destinationIP == portal {
 					if ip.SourceIP() == gateway && t.SourcePort() == gatewayPort {
 						tup := tab.tupleOf(t.DestinationPort())
 						if tup == zeroTuple {
@@ -120,7 +124,7 @@ func Start(
 				} else {
 					tup := tuple{
 						SourceAddr:      netip.AddrPortFrom(ip.SourceIP(), t.SourcePort()),
-						DestinationAddr: netip.AddrPortFrom(ip.DestinationIP(), t.DestinationPort()),
+						DestinationAddr: netip.AddrPortFrom(destinationIP, t.DestinationPort()),
 					}
 
 					port := tab.portOf(tup)
@@ -158,10 +162,8 @@ func Start(
 
 				i.SetType(tcpip.ICMPTypePingResponse)
 
-				source := ip.SourceIP()
-				destination := ip.DestinationIP()
-				ip.SetSourceIP(destination)
-				ip.SetDestinationIP(source)
+				ip.SetDestinationIP(ip.SourceIP())
+				ip.SetSourceIP(destinationIP)
 
 				ip.ResetChecksum()
 				i.ResetChecksum()
@@ -176,10 +178,8 @@ func Start(
 
 				i.SetType(tcpip.ICMPv6EchoReply)
 
-				source := ip.SourceIP()
-				destination := ip.DestinationIP()
-				ip.SetSourceIP(destination)
-				ip.SetDestinationIP(source)
+				ip.SetDestinationIP(ip.SourceIP())
+				ip.SetSourceIP(destinationIP)
 
 				ip.ResetChecksum()
 				i.ResetChecksum(ip.PseudoSum())
diff --git a/listener/tun/ipstack/system/mars/nat/udp.go b/listener/tun/ipstack/system/mars/nat/udp.go
index 4e7a4f9e..6cc7faee 100644
--- a/listener/tun/ipstack/system/mars/nat/udp.go
+++ b/listener/tun/ipstack/system/mars/nat/udp.go
@@ -7,6 +7,7 @@ import (
 	"net/netip"
 	"sync"
 
+	"github.com/Dreamacro/clash/common/nnip"
 	"github.com/Dreamacro/clash/common/pool"
 	"github.com/Dreamacro/clash/listener/tun/ipstack/system/mars/tcpip"
 )
@@ -71,11 +72,8 @@ func (u *UDP) WriteTo(buf []byte, local net.Addr, remote net.Addr) (int, error)
 		return 0, net.InvalidAddrError("invalid addr")
 	}
 
-	srcIP, _ := netip.AddrFromSlice(srcAddr.IP)
-	dstIp, _ := netip.AddrFromSlice(dstAddr.IP)
-
-	srcAddrPort := netip.AddrPortFrom(srcIP.Unmap(), uint16(srcAddr.Port))
-	dstAddrPort := netip.AddrPortFrom(dstIp.Unmap(), uint16(dstAddr.Port))
+	srcAddrPort := netip.AddrPortFrom(nnip.IpToAddr(srcAddr.IP), uint16(srcAddr.Port))
+	dstAddrPort := netip.AddrPortFrom(nnip.IpToAddr(dstAddr.IP), uint16(dstAddr.Port))
 
 	if !srcAddrPort.Addr().Is4() || !dstAddrPort.Addr().Is4() {
 		return 0, net.InvalidAddrError("invalid ip version")
diff --git a/listener/tun/ipstack/system/mars/tcpip/ip.go b/listener/tun/ipstack/system/mars/tcpip/ip.go
index 1ca49d8d..88237b01 100644
--- a/listener/tun/ipstack/system/mars/tcpip/ip.go
+++ b/listener/tun/ipstack/system/mars/tcpip/ip.go
@@ -118,12 +118,6 @@ func (p IPv4Packet) SetFlags(flags byte) {
 	p[6] |= flags << 5
 }
 
-func (p IPv4Packet) Offset() uint16 {
-	offset := binary.BigEndian.Uint16(p[6:8])
-
-	return (offset & 0x1fff) * 8
-}
-
 func (p IPv4Packet) SourceIP() netip.Addr {
 	return netip.AddrFrom4([4]byte{p[12], p[13], p[14], p[15]})
 }
diff --git a/listener/tun/ipstack/system/stack.go b/listener/tun/ipstack/system/stack.go
index d0b24e3a..6ffc6d7d 100644
--- a/listener/tun/ipstack/system/stack.go
+++ b/listener/tun/ipstack/system/stack.go
@@ -10,6 +10,7 @@ import (
 	"time"
 
 	"github.com/Dreamacro/clash/adapter/inbound"
+	"github.com/Dreamacro/clash/common/nnip"
 	"github.com/Dreamacro/clash/common/pool"
 	C "github.com/Dreamacro/clash/constant"
 	"github.com/Dreamacro/clash/context"
@@ -45,11 +46,12 @@ func (s *sysStack) Close() error {
 
 func New(device device.Device, dnsHijack []netip.AddrPort, tunAddress netip.Prefix, tcpIn chan<- C.ConnContext, udpIn chan<- *inbound.PacketAdapter) (ipstack.Stack, error) {
 	var (
-		gateway = tunAddress.Masked().Addr().Next()
-		portal  = gateway.Next()
+		gateway   = tunAddress.Masked().Addr().Next()
+		portal    = gateway.Next()
+		broadcast = nnip.UnMasked(tunAddress)
 	)
 
-	stack, err := mars.StartListener(device, gateway, portal)
+	stack, err := mars.StartListener(device, gateway, portal, broadcast)
 	if err != nil {
 		_ = device.Close()
 
@@ -81,24 +83,26 @@ func New(device device.Device, dnsHijack []netip.AddrPort, tunAddress netip.Pref
 			lAddr := conn.LocalAddr().(*net.TCPAddr)
 			rAddr := conn.RemoteAddr().(*net.TCPAddr)
 
-			rAddrIp, _ := netip.AddrFromSlice(rAddr.IP)
-			rAddrPort := netip.AddrPortFrom(rAddrIp, uint16(rAddr.Port))
+			rAddrPort := netip.AddrPortFrom(nnip.IpToAddr(rAddr.IP), uint16(rAddr.Port))
+
+			if rAddrPort.Addr().IsLoopback() {
+				_ = conn.Close()
+
+				continue
+			}
 
 			if D.ShouldHijackDns(dnsAddr, rAddrPort) {
 				go func() {
 					log.Debugln("[TUN] hijack dns tcp: %s", rAddrPort.String())
 
-					defer func(conn net.Conn) {
-						_ = conn.Close()
-					}(conn)
-
 					buf := pool.Get(pool.UDPBufferSize)
-					defer func(buf []byte) {
+					defer func() {
 						_ = pool.Put(buf)
-					}(buf)
+						_ = conn.Close()
+					}()
 
 					for {
-						if err = conn.SetReadDeadline(time.Now().Add(C.DefaultTCPTimeout)); err != nil {
+						if conn.SetReadDeadline(time.Now().Add(C.DefaultTCPTimeout)) != nil {
 							break
 						}
 
@@ -162,8 +166,13 @@ func New(device device.Device, dnsHijack []netip.AddrPort, tunAddress netip.Pref
 			lAddr := lRAddr.(*net.UDPAddr)
 			rAddr := rRAddr.(*net.UDPAddr)
 
-			rAddrIp, _ := netip.AddrFromSlice(rAddr.IP)
-			rAddrPort := netip.AddrPortFrom(rAddrIp, uint16(rAddr.Port))
+			rAddrPort := netip.AddrPortFrom(nnip.IpToAddr(rAddr.IP), uint16(rAddr.Port))
+
+			if rAddrPort.Addr().IsLoopback() {
+				_ = pool.Put(buf)
+
+				continue
+			}
 
 			if D.ShouldHijackDns(dnsAddr, rAddrPort) {
 				go func() {
diff --git a/listener/tun/tun_adapter.go b/listener/tun/tun_adapter.go
index 46caa35c..92f8f129 100644
--- a/listener/tun/tun_adapter.go
+++ b/listener/tun/tun_adapter.go
@@ -149,7 +149,8 @@ func setAtLatest(stackType C.TUNStack, devName string) {
 
 	switch runtime.GOOS {
 	case "darwin":
-		_, _ = cmd.ExecCmd("sysctl net.inet.ip.forwarding=1")
+		// _, _ = cmd.ExecCmd("sysctl -w net.inet.ip.forwarding=1")
+		// _, _ = cmd.ExecCmd("sysctl -w net.inet6.ip6.forwarding=1")
 	case "windows":
 		_, _ = cmd.ExecCmd("ipconfig /renew")
 	case "linux":