[Refactor] gvisor support hijack dns list

dns-hijack:
 - 1.1.1.1
 - 8.8.8.8:53
 - tcp://1.1.1.1:53
 - udp://223.5.5.5
 - 10.0.0.1:5353

common/net/tcpip.go

@@ -0,0 +1,46 @@
+package net
+
+import (
+	"fmt"
+	"net"
+	"strings"
+)
+
+func SplitNetworkType(s string) (string, string, error) {
+	var (
+		shecme   string
+		hostPort string
+	)
+	result := strings.Split(s, "://")
+	if len(result) == 2 {
+		shecme = result[0]
+		hostPort = result[1]
+	} else if len(result) == 1 {
+		hostPort = result[0]
+	} else {
+		return "", "", fmt.Errorf("tcp/udp style error")
+	}
+
+	if len(shecme) == 0 {
+		shecme = "udp"
+	}
+
+	if shecme != "tcp" && shecme != "udp" {
+		return "", "", fmt.Errorf("scheme should be tcp:// or udp://")
+	} else {
+		return shecme, hostPort, nil
+	}
+}
+
+func SplitHostPort(s string) (host, port string, hasPort bool, err error) {
+	temp := s
+	hasPort = true
+
+	if !strings.Contains(s, ":") && !strings.Contains(s, "]:") {
+		temp += ":0"
+		hasPort = false
+	}
+
+	host, port, err = net.SplitHostPort(temp)
+	return
+}

listener/tun/ipstack/gvisor/tun.go

@@ -36,7 +36,7 @@ const nicID tcpip.NICID = 1
 type gvisorAdapter struct {
 	device    dev.TunDevice
 	ipstack   *stack.Stack
-	dnsServers []*DNSServer
+	dnsServer *DNSServer
 	udpIn     chan<- *inbound.PacketAdapter
 
 	stackName string
@@ -47,7 +47,7 @@ type gvisorAdapter struct {
 	writeHandle *channel.NotificationHandle
 }
 
-// GvisorAdapter create GvisorAdapter
+// NewAdapter GvisorAdapter create GvisorAdapter
 func NewAdapter(device dev.TunDevice, conf config.Tun, tcpIn chan<- C.ConnContext, udpIn chan<- *inbound.PacketAdapter) (ipstack.TunAdapter, error) {
 	ipstack := stack.New(stack.Options{
 		NetworkProtocols:   []stack.NetworkProtocolFactory{ipv4.NewProtocol, ipv6.NewProtocol},
@@ -132,7 +132,7 @@ func (t *gvisorAdapter) AutoRoute() bool {
 
 // Close close the TunAdapter
 func (t *gvisorAdapter) Close() {
-	t.StopAllDNSServer()
+	t.StopDNSServer()
 	if t.ipstack != nil {
 		t.ipstack.Close()
 	}

listener/tun/ipstack/gvisor/tundns.go

@@ -2,13 +2,14 @@ package gvisor
 
 import (
 	"fmt"
+	"gvisor.dev/gvisor/pkg/tcpip/adapters/gonet"
 	"net"
 
+	Common "github.com/Dreamacro/clash/common/net"
 	"github.com/Dreamacro/clash/dns"
 	"github.com/Dreamacro/clash/log"
 	D "github.com/miekg/dns"
 	"gvisor.dev/gvisor/pkg/tcpip"
-	"gvisor.dev/gvisor/pkg/tcpip/adapters/gonet"
 	"gvisor.dev/gvisor/pkg/tcpip/buffer"
 	"gvisor.dev/gvisor/pkg/tcpip/header"
 	"gvisor.dev/gvisor/pkg/tcpip/network/ipv4"
@@ -23,15 +24,33 @@ var (
 	ipv6Zero = tcpip.Address(net.IPv6zero.To16())
 )
 
+type ListenerWrap struct {
+	net.Listener
+	listener net.Listener
+}
+
+func (l *ListenerWrap) Accept() (conn net.Conn, err error) {
+	conn, err = l.listener.Accept()
+	log.Debugln("[DNS] hijack tcp:%s", l.Addr())
+	return
+}
+
+func (l *ListenerWrap) Close() error {
+	return l.listener.Close()
+}
+
+func (l *ListenerWrap) Addr() net.Addr {
+	return l.listener.Addr()
+}
+
 // DNSServer is DNS Server listening on tun devcice
 type DNSServer struct {
-	*dns.Server
+	dnsServers     []*dns.Server
+	tcpListeners   []net.Listener
 	resolver       *dns.Resolver
-
 	stack          *stack.Stack
-	tcpListener   net.Listener
+	udpEndpoints   []*dnsEndpoint
-	udpEndpoint   *dnsEndpoint
+	udpEndpointIDs []*stack.TransportEndpointID
-	udpEndpointID *stack.TransportEndpointID
 	tcpip.NICID
 }
 
@@ -66,6 +85,7 @@ func (e *dnsEndpoint) HandlePacket(id stack.TransportEndpointID, pkt *stack.Pack
 	var msg D.Msg
 	msg.Unpack(pkt.Data().AsRange().ToOwnedView())
 	writer := dnsResponseWriter{s: e.stack, pkt: pkt, id: id}
+	log.Debugln("[DNS] hijack udp:%s:%d", id.LocalAddress.String(), id.LocalPort)
 	go e.server.ServeDNS(&writer, &msg)
 }
 
@@ -129,26 +149,66 @@ func (w *dnsResponseWriter) Close() error {
 }
 
 // CreateDNSServer create a dns server on given netstack
-func CreateDNSServer(s *stack.Stack, resolver *dns.Resolver, mapper *dns.ResolverEnhancer, ip net.IP, port int, nicID tcpip.NICID) (*DNSServer, error) {
+func CreateDNSServer(s *stack.Stack, resolver *dns.Resolver, mapper *dns.ResolverEnhancer, dnsHijack []net.Addr, nicID tcpip.NICID) (*DNSServer, error) {
-	var v4 bool
 	var err error
+	handler := dns.NewHandler(resolver, mapper)
+	serverIn := &dns.Server{}
+	serverIn.SetHandler(handler)
+	tcpDnsArr := make([]net.TCPAddr, 0, len(dnsHijack))
+	udpDnsArr := make([]net.UDPAddr, 0, len(dnsHijack))
+	for _, d := range dnsHijack {
+		switch d.(type) {
+		case *net.TCPAddr:
+			{
+				tcpDnsArr = append(tcpDnsArr, *d.(*net.TCPAddr))
+				break
+			}
+		case *net.UDPAddr:
+			{
+				udpDnsArr = append(udpDnsArr, *d.(*net.UDPAddr))
+				break
+			}
+		}
+	}
 
+	endpoints, ids := hijackUdpDns(udpDnsArr, s, serverIn)
+	tcpListeners, dnsServers := hijackTcpDns(tcpDnsArr, s, serverIn)
+	server := &DNSServer{
+		resolver:       resolver,
+		stack:          s,
+		udpEndpoints:   endpoints,
+		udpEndpointIDs: ids,
+		NICID:          nicID,
+		tcpListeners:   tcpListeners,
+	}
+
+	server.dnsServers = dnsServers
+
+	return server, err
+}
+
+func hijackUdpDns(dnsArr []net.UDPAddr, s *stack.Stack, serverIn *dns.Server) ([]*dnsEndpoint, []*stack.TransportEndpointID) {
+	endpoints := make([]*dnsEndpoint, len(dnsArr))
+	ids := make([]*stack.TransportEndpointID, len(dnsArr))
+	for i, dns := range dnsArr {
+		port := dns.Port
+		ip := dns.IP
 		address := tcpip.FullAddress{NIC: nicID, Port: uint16(port)}
 		var protocol tcpip.NetworkProtocolNumber
 		if ip.To4() != nil {
-		v4 = true
 			address.Addr = tcpip.Address(ip.To4())
 			protocol = ipv4.ProtocolNumber
 
 		} else {
-		v4 = false
 			address.Addr = tcpip.Address(ip.To16())
 			protocol = ipv6.ProtocolNumber
 		}
+
 		protocolAddr := tcpip.ProtocolAddress{
 			Protocol:          protocol,
 			AddressWithPrefix: address.Addr.WithPrefix(),
 		}
+
 		// netstack will only reassemble IP fragments when its' dest ip address is registered in NIC.endpoints
 		if err := s.AddProtocolAddress(nicID, protocolAddr, stack.AddressProperties{}); err != nil {
 			log.Errorln("AddProtocolAddress(%d, %+v, {}): %s", nicID, protocolAddr, err)
@@ -158,10 +218,6 @@ func CreateDNSServer(s *stack.Stack, resolver *dns.Resolver, mapper *dns.Resolve
 			address.Addr = ""
 		}
 
-	handler := dns.NewHandler(resolver, mapper)
-	serverIn := &dns.Server{}
-	serverIn.SetHandler(handler)
-
 		// UDP DNS
 		id := &stack.TransportEndpointID{
 			LocalAddress:  address.Addr,
@@ -190,44 +246,72 @@ func CreateDNSServer(s *stack.Stack, resolver *dns.Resolver, mapper *dns.Resolve
 			log.Errorln("Unable to start UDP DNS on tun:  %v", tcpiperr.String())
 		}
 
-	// TCP DNS
+		ids[i] = id
+		endpoints[i] = endpoint
+	}
+
+	return endpoints, ids
+}
+
+func hijackTcpDns(dnsArr []net.TCPAddr, s *stack.Stack, serverIn *dns.Server) ([]net.Listener, []*dns.Server) {
+	tcpListeners := make([]net.Listener, len(dnsArr))
+	dnsServers := make([]*dns.Server, len(dnsArr))
+
+	for i, dnsAddr := range dnsArr {
 		var tcpListener net.Listener
+		var v4 bool
+		var err error
+		port := dnsAddr.Port
+		ip := dnsAddr.IP
+		address := tcpip.FullAddress{NIC: nicID, Port: uint16(port)}
+		if ip.To4() != nil {
+			address.Addr = tcpip.Address(ip.To4())
+			v4 = true
+		} else {
+			address.Addr = tcpip.Address(ip.To16())
+			v4 = false
+		}
+
 		if v4 {
 			tcpListener, err = gonet.ListenTCP(s, address, ipv4.ProtocolNumber)
 		} else {
 			tcpListener, err = gonet.ListenTCP(s, address, ipv6.ProtocolNumber)
 		}
+
 		if err != nil {
-		return nil, fmt.Errorf("can not listen on tun: %v", err)
+			log.Errorln("can not listen on tun: %v, hijack tcp[%s] failed", err, dnsAddr)
+		} else {
+			tcpListeners[i] = tcpListener
+			server := &D.Server{Listener: &ListenerWrap{
+				listener: tcpListener,
+			}, Handler: serverIn}
+			dnsServer := dns.Server{}
+			dnsServer.Server = server
+			go dnsServer.ActivateAndServe()
+			dnsServers[i] = &dnsServer
 		}
 
-	server := &DNSServer{
-		Server:        serverIn,
-		resolver:      resolver,
-		stack:         s,
-		tcpListener:   tcpListener,
-		udpEndpoint:   endpoint,
-		udpEndpointID: id,
-		NICID:         nicID,
 	}
-	server.SetHandler(handler)
+	//
-	server.Server.Server = &D.Server{Listener: tcpListener, Handler: server}
+	//for _, listener := range tcpListeners {
+	//	server := &D.Server{Listener: listener, Handler: serverIn}
+	//
+	//	dnsServers = append(dnsServers, &dnsServer)
+	//	go dnsServer.ActivateAndServe()
+	//}
 
-	go func() {
+	return tcpListeners, dnsServers
-		server.ActivateAndServe()
-	}()
-
-	return server, err
 }
 
 // Stop stop the DNS Server on tun
 func (s *DNSServer) Stop() {
-	// shutdown TCP DNS Server
+	if s == nil {
-	s.Server.Shutdown()
+		return
-	// remove TCP endpoint from stack
-	if s.Listener != nil {
-		s.Listener.Close()
 	}
+
+	for i := 0; i < len(s.udpEndpointIDs); i++ {
+		ep := s.udpEndpoints[i]
+		id := s.udpEndpointIDs[i]
 		// remove udp endpoint from stack
 		s.stack.UnregisterTransportEndpoint(
 			[]tcpip.NetworkProtocolNumber{
@@ -235,61 +319,106 @@ func (s *DNSServer) Stop() {
 				ipv6.ProtocolNumber,
 			},
 			udp.ProtocolNumber,
-		*s.udpEndpointID,
+			*id,
-		s.udpEndpoint,
+			ep,
 			ports.Flags{LoadBalanced: true}, // should match the RegisterTransportEndpoint
 			s.NICID)
+	}
+
+	for _, server := range s.dnsServers {
+		server.Shutdown()
+	}
+
+	for _, listener := range s.tcpListeners {
+		listener.Close()
+	}
 }
 
 // DnsHijack return the listening address of DNS Server
 func (t *gvisorAdapter) DnsHijack() []string {
-	results := make([]string, len(t.dnsServers))
+	dnsHijackArr := make([]string, len(t.dnsServer.udpEndpoints))
-	for i, dnsServer := range t.dnsServers {
+	for _, id := range t.dnsServer.udpEndpointIDs {
-		id := dnsServer.udpEndpointID
+		dnsHijackArr = append(dnsHijackArr, fmt.Sprintf("%s:%d", id.LocalAddress.String(), id.LocalPort))
-		results[i] = fmt.Sprintf("%s:%d", id.LocalAddress.String(), id.LocalPort)
 	}
 
-	return results
+	return dnsHijackArr
 }
 
-func (t *gvisorAdapter) StopAllDNSServer() {
+func (t *gvisorAdapter) StopDNSServer() {
-	for _, dnsServer := range t.dnsServers {
+	t.dnsServer.Stop()
-		dnsServer.Stop()
-	}
 	log.Debugln("tun DNS server stoped")
-	t.dnsServers = nil
+	t.dnsServer = nil
 }
 
 // ReCreateDNSServer recreate the DNS Server on tun
-func (t *gvisorAdapter) ReCreateDNSServer(resolver *dns.Resolver, mapper *dns.ResolverEnhancer, addrs []string) error {
+func (t *gvisorAdapter) ReCreateDNSServer(resolver *dns.Resolver, mapper *dns.ResolverEnhancer, dnsHijackArr []string) error {
-	t.StopAllDNSServer()
+	t.StopDNSServer()
 
 	if resolver == nil {
 		return fmt.Errorf("failed to create DNS server on tun: resolver not provided")
 	}
 
-	if len(addrs) == 0 {
+	if len(dnsHijackArr) == 0 {
 		return fmt.Errorf("failed to create DNS server on tun: len(addrs) == 0")
 	}
-	for _, addr := range addrs {
 	var err error
-		_, port, err := net.SplitHostPort(addr)
+	var addrs []net.Addr
-		if port == "0" || port == "" || err != nil {
+	for _, addr := range dnsHijackArr {
-			return nil
+		var (
-		}
+			addrType string
+			hostPort string
+		)
 
-		udpAddr, err := net.ResolveUDPAddr("udp", addr)
+		addrType, hostPort, err = Common.SplitNetworkType(addr)
 		if err != nil {
 			return err
 		}
 
-		server, err := CreateDNSServer(t.ipstack, resolver, mapper, udpAddr.IP, udpAddr.Port, nicID)
+		var (
+			host, port string
+			hasPort    bool
+		)
+
+		host, port, hasPort, err = Common.SplitHostPort(hostPort)
+		if !hasPort {
+			port = "53"
+		}
+
+		switch addrType {
+		case "udp", "":
+			{
+				var udpDNS *net.UDPAddr
+				udpDNS, err = net.ResolveUDPAddr("udp", net.JoinHostPort(host, port))
 				if err != nil {
 					return err
 				}
-		t.dnsServers = append(t.dnsServers, server)
+
-		log.Infoln("Tun DNS server listening at: %s, fake ip enabled: %v", addr, mapper.FakeIPEnabled())
+				addrs = append(addrs, udpDNS)
+				break
 			}
+		case "tcp":
+			{
+				var tcpDNS *net.TCPAddr
+				tcpDNS, err = net.ResolveTCPAddr("tcp", net.JoinHostPort(host, port))
+				if err != nil {
+					return err
+				}
+
+				addrs = append(addrs, tcpDNS)
+				break
+			}
+		default:
+			err = fmt.Errorf("unspported dns scheme:%s", addrType)
+		}
+
+	}
+
+	server, err := CreateDNSServer(t.ipstack, resolver, mapper, addrs, nicID)
+	if err != nil {
+		return err
+	}
+
+	t.dnsServer = server
 
 	return nil
 }