Feature: add custom DNS support (#56)

adapters/inbound/socket.go

@@ -29,9 +29,12 @@ func (s *SocketAdapter) Conn() net.Conn {
 }
 
 // NewSocket is SocketAdapter generator
-func NewSocket(target socks.Addr, conn net.Conn) *SocketAdapter {
+func NewSocket(target socks.Addr, conn net.Conn, source C.SourceType) *SocketAdapter {
+	metadata := parseSocksAddr(target)
+	metadata.Source = source
+
 	return &SocketAdapter{
 		conn:     conn,
-		metadata: parseSocksAddr(target),
+		metadata: metadata,
 	}
 }

adapters/inbound/util.go

@@ -10,32 +10,26 @@ import (
 )
 
 func parseSocksAddr(target socks.Addr) *C.Metadata {
-	var host, port string
+	metadata := &C.Metadata{
-	var ip net.IP
+		NetWork:  C.TCP,
+		AddrType: int(target[0]),
+	}
 
 	switch target[0] {
 	case socks.AtypDomainName:
-		host = string(target[2 : 2+target[1]])
+		metadata.Host = string(target[2 : 2+target[1]])
-		port = strconv.Itoa((int(target[2+target[1]]) << 8) | int(target[2+target[1]+1]))
+		metadata.Port = strconv.Itoa((int(target[2+target[1]]) << 8) | int(target[2+target[1]+1]))
-		ipAddr, err := net.ResolveIPAddr("ip", host)
-		if err == nil {
-			ip = ipAddr.IP
-		}
 	case socks.AtypIPv4:
-		ip = net.IP(target[1 : 1+net.IPv4len])
+		ip := net.IP(target[1 : 1+net.IPv4len])
-		port = strconv.Itoa((int(target[1+net.IPv4len]) << 8) | int(target[1+net.IPv4len+1]))
+		metadata.IP = &ip
+		metadata.Port = strconv.Itoa((int(target[1+net.IPv4len]) << 8) | int(target[1+net.IPv4len+1]))
 	case socks.AtypIPv6:
-		ip = net.IP(target[1 : 1+net.IPv6len])
+		ip := net.IP(target[1 : 1+net.IPv6len])
-		port = strconv.Itoa((int(target[1+net.IPv6len]) << 8) | int(target[1+net.IPv6len+1]))
+		metadata.IP = &ip
+		metadata.Port = strconv.Itoa((int(target[1+net.IPv6len]) << 8) | int(target[1+net.IPv6len+1]))
 	}
 
-	return &C.Metadata{
+	return metadata
-		NetWork:  C.TCP,
-		AddrType: int(target[0]),
-		Host:     host,
-		IP:       &ip,
-		Port:     port,
-	}
 }
 
 func parseHTTPAddr(request *http.Request) *C.Metadata {
@@ -44,28 +38,26 @@ func parseHTTPAddr(request *http.Request) *C.Metadata {
 	if port == "" {
 		port = "80"
 	}
-	ipAddr, err := net.ResolveIPAddr("ip", host)
-	var resolveIP *net.IP
-	if err == nil {
-		resolveIP = &ipAddr.IP
-	}
 
-	var addType int
+	metadata := &C.Metadata{
-	ip := net.ParseIP(host)
-	switch {
-	case ip == nil:
-		addType = socks.AtypDomainName
-	case ip.To4() == nil:
-		addType = socks.AtypIPv6
-	default:
-		addType = socks.AtypIPv4
-	}
-
-	return &C.Metadata{
 		NetWork:  C.TCP,
-		AddrType: addType,
+		Source:   C.HTTP,
+		AddrType: C.AtypDomainName,
 		Host:     host,
-		IP:       resolveIP,
+		IP:       nil,
 		Port:     port,
 	}
+
+	ip := net.ParseIP(host)
+	if ip != nil {
+		switch {
+		case ip.To4() == nil:
+			metadata.AddrType = C.AtypIPv6
+		default:
+			metadata.AddrType = C.AtypIPv4
+		}
+		metadata.IP = &ip
+	}
+
+	return metadata
 }

adapters/outbound/direct.go

@@ -33,7 +33,12 @@ func (d *Direct) Type() C.AdapterType {
 }
 
 func (d *Direct) Generator(metadata *C.Metadata) (adapter C.ProxyAdapter, err error) {
-	c, err := net.DialTimeout("tcp", net.JoinHostPort(metadata.String(), metadata.Port), tcpTimeout)
+	address := net.JoinHostPort(metadata.Host, metadata.Port)
+	if metadata.IP != nil {
+		address = net.JoinHostPort(metadata.IP.String(), metadata.Port)
+	}
+
+	c, err := net.DialTimeout("tcp", address, tcpTimeout)
 	if err != nil {
 		return
 	}

common/cache/cache.go

@@ -0,0 +1,91 @@
+package cache
+
+import (
+	"runtime"
+	"sync"
+	"time"
+)
+
+// Cache store element with a expired time
+type Cache struct {
+	*cache
+}
+
+type cache struct {
+	mapping sync.Map
+	janitor *janitor
+}
+
+type element struct {
+	Expired time.Time
+	Payload interface{}
+}
+
+// Put element in Cache with its ttl
+func (c *cache) Put(key interface{}, payload interface{}, ttl time.Duration) {
+	c.mapping.Store(key, &element{
+		Payload: payload,
+		Expired: time.Now().Add(ttl),
+	})
+}
+
+// Get element in Cache, and drop when it expired
+func (c *cache) Get(key interface{}) interface{} {
+	item, exist := c.mapping.Load(key)
+	if !exist {
+		return nil
+	}
+	elm := item.(*element)
+	// expired
+	if time.Since(elm.Expired) > 0 {
+		c.mapping.Delete(key)
+		return nil
+	}
+	return elm.Payload
+}
+
+func (c *cache) cleanup() {
+	c.mapping.Range(func(k, v interface{}) bool {
+		key := k.(string)
+		elm := v.(*element)
+		if time.Since(elm.Expired) > 0 {
+			c.mapping.Delete(key)
+		}
+		return true
+	})
+}
+
+type janitor struct {
+	interval time.Duration
+	stop     chan struct{}
+}
+
+func (j *janitor) process(c *cache) {
+	ticker := time.NewTicker(j.interval)
+	for {
+		select {
+		case <-ticker.C:
+			c.cleanup()
+		case <-j.stop:
+			ticker.Stop()
+			return
+		}
+	}
+}
+
+func stopJanitor(c *Cache) {
+	c.janitor.stop <- struct{}{}
+}
+
+// New return *Cache
+func New(interval time.Duration) *Cache {
+	j := &janitor{
+		interval: interval,
+		stop:     make(chan struct{}),
+	}
+	c := &cache{janitor: j}
+	go j.process(c)
+	C := &Cache{c}
+	runtime.SetFinalizer(C, stopJanitor)
+	return C
+}

common/cache/cache_test.go

@@ -0,0 +1,70 @@
+package cache
+
+import (
+	"runtime"
+	"testing"
+	"time"
+)
+
+func TestCache_Basic(t *testing.T) {
+	interval := 200 * time.Millisecond
+	ttl := 20 * time.Millisecond
+	c := New(interval)
+	c.Put("int", 1, ttl)
+	c.Put("string", "a", ttl)
+
+	i := c.Get("int")
+	if i.(int) != 1 {
+		t.Error("should recv 1")
+	}
+
+	s := c.Get("string")
+	if s.(string) != "a" {
+		t.Error("should recv 'a'")
+	}
+}
+
+func TestCache_TTL(t *testing.T) {
+	interval := 200 * time.Millisecond
+	ttl := 20 * time.Millisecond
+	c := New(interval)
+	c.Put("int", 1, ttl)
+
+	i := c.Get("int")
+	if i.(int) != 1 {
+		t.Error("should recv 1")
+	}
+
+	time.Sleep(ttl * 2)
+	i = c.Get("int")
+	if i != nil {
+		t.Error("should recv nil")
+	}
+}
+
+func TestCache_AutoCleanup(t *testing.T) {
+	interval := 10 * time.Millisecond
+	ttl := 15 * time.Millisecond
+	c := New(interval)
+	c.Put("int", 1, ttl)
+
+	time.Sleep(ttl * 2)
+	i := c.Get("int")
+	if i != nil {
+		t.Error("should recv nil")
+	}
+}
+
+func TestCache_AutoGC(t *testing.T) {
+	sign := make(chan struct{})
+	go func() {
+		interval := 10 * time.Millisecond
+		ttl := 15 * time.Millisecond
+		c := New(interval)
+		c.Put("int", 1, ttl)
+		sign <- struct{}{}
+	}()
+
+	<-sign
+	runtime.GC()
+}

common/picker/picker.go

@@ -0,0 +1,22 @@
+package picker
+
+import "context"
+
+func SelectFast(ctx context.Context, in <-chan interface{}) <-chan interface{} {
+	out := make(chan interface{})
+	go func() {
+		select {
+		case p, open := <-in:
+			if open {
+				out <- p
+			}
+		case <-ctx.Done():
+		}
+
+		close(out)
+		for range in {
+		}
+	}()
+
+	return out
+}

common/picker/picker_test.go

@@ -0,0 +1,44 @@
+package picker
+
+import (
+	"context"
+	"testing"
+	"time"
+)
+
+func sleepAndSend(delay int, in chan<- interface{}, input interface{}) {
+	time.Sleep(time.Millisecond * time.Duration(delay))
+	in <- input
+}
+
+func sleepAndClose(delay int, in chan interface{}) {
+	time.Sleep(time.Millisecond * time.Duration(delay))
+	close(in)
+}
+
+func TestPicker_Basic(t *testing.T) {
+	in := make(chan interface{})
+	fast := SelectFast(context.Background(), in)
+	go sleepAndSend(20, in, 1)
+	go sleepAndSend(30, in, 2)
+	go sleepAndClose(40, in)
+
+	number, exist := <-fast
+	if !exist || number != 1 {
+		t.Error("should recv 1", exist, number)
+	}
+}
+
+func TestPicker_Timeout(t *testing.T) {
+	in := make(chan interface{})
+	ctx, cancel := context.WithTimeout(context.Background(), time.Millisecond*5)
+	defer cancel()
+	fast := SelectFast(ctx, in)
+	go sleepAndSend(20, in, 1)
+	go sleepAndClose(30, in)
+
+	_, exist := <-fast
+	if exist {
+		t.Error("should recv false")
+	}
+}

config/config.go

@@ -3,12 +3,15 @@ package config
 import (
 	"fmt"
 	"io/ioutil"
+	"net"
+	"net/url"
 	"os"
 	"strings"
 
 	adapters "github.com/Dreamacro/clash/adapters/outbound"
 	"github.com/Dreamacro/clash/common/structure"
 	C "github.com/Dreamacro/clash/constant"
+	"github.com/Dreamacro/clash/dns"
 	"github.com/Dreamacro/clash/log"
 	R "github.com/Dreamacro/clash/rules"
 	T "github.com/Dreamacro/clash/tunnel"
@@ -28,28 +31,49 @@ type General struct {
 	Secret             string       `json:"secret,omitempty"`
 }
 
-type rawConfig struct {
+// DNS config
-	Port               int    `yaml:"port"`
+type DNS struct {
-	SocksPort          int    `yaml:"socks-port"`
+	Enable       bool             `yaml:"enable"`
-	RedirPort          int    `yaml:"redir-port"`
+	IPv6         bool             `yaml:"ipv6"`
-	AllowLan           bool   `yaml:"allow-lan"`
+	NameServer   []dns.NameServer `yaml:"nameserver"`
-	Mode               string `yaml:"mode"`
+	Fallback     []dns.NameServer `yaml:"fallback"`
-	LogLevel           string `yaml:"log-level"`
+	Listen       string           `yaml:"listen"`
-	ExternalController string `yaml:"external-controller"`
+	EnhancedMode dns.EnhancedMode `yaml:"enhanced-mode"`
-	Secret             string `yaml:"secret"`
-
-	Proxy      []map[string]interface{} `yaml:"Proxy"`
-	ProxyGroup []map[string]interface{} `yaml:"Proxy Group"`
-	Rule       []string                 `yaml:"Rule"`
 }
 
 // Config is clash config manager
 type Config struct {
 	General *General
+	DNS     *DNS
 	Rules   []C.Rule
 	Proxies map[string]C.Proxy
 }
 
+type rawDNS struct {
+	Enable       bool             `yaml:"enable"`
+	IPv6         bool             `yaml:"ipv6"`
+	NameServer   []string         `yaml:"nameserver"`
+	Fallback     []string         `yaml:"fallback"`
+	Listen       string           `yaml:"listen"`
+	EnhancedMode dns.EnhancedMode `yaml:"enhanced-mode"`
+}
+
+type rawConfig struct {
+	Port               int          `yaml:"port"`
+	SocksPort          int          `yaml:"socks-port"`
+	RedirPort          int          `yaml:"redir-port"`
+	AllowLan           bool         `yaml:"allow-lan"`
+	Mode               T.Mode       `yaml:"mode"`
+	LogLevel           log.LogLevel `yaml:"log-level"`
+	ExternalController string       `yaml:"external-controller"`
+	Secret             string       `yaml:"secret"`
+
+	DNS        *rawDNS                  `yaml:"dns"`
+	Proxy      []map[string]interface{} `yaml:"Proxy"`
+	ProxyGroup []map[string]interface{} `yaml:"Proxy Group"`
+	Rule       []string                 `yaml:"Rule"`
+}
+
 func readConfig(path string) (*rawConfig, error) {
 	if _, err := os.Stat(path); os.IsNotExist(err) {
 		return nil, err
@@ -66,8 +90,8 @@ func readConfig(path string) (*rawConfig, error) {
 	// config with some default value
 	rawConfig := &rawConfig{
 		AllowLan:   false,
-		Mode:       T.Rule.String(),
+		Mode:       T.Rule,
-		LogLevel:   log.INFO.String(),
+		LogLevel:   log.INFO,
 		Rule:       []string{},
 		Proxy:      []map[string]interface{}{},
 		ProxyGroup: []map[string]interface{}{},
@@ -103,6 +127,12 @@ func Parse(path string) (*Config, error) {
 	}
 	config.Rules = rules
 
+	dnsCfg, err := parseDNS(rawCfg.DNS)
+	if err != nil {
+		return nil, err
+	}
+	config.DNS = dnsCfg
+
 	return config, nil
 }
 
@@ -111,20 +141,10 @@ func parseGeneral(cfg *rawConfig) (*General, error) {
 	socksPort := cfg.SocksPort
 	redirPort := cfg.RedirPort
 	allowLan := cfg.AllowLan
-	logLevelString := cfg.LogLevel
-	modeString := cfg.Mode
 	externalController := cfg.ExternalController
 	secret := cfg.Secret
-
+	mode := cfg.Mode
-	mode, exist := T.ModeMapping[modeString]
+	logLevel := cfg.LogLevel
-	if !exist {
-		return nil, fmt.Errorf("General.mode value invalid")
-	}
-
-	logLevel, exist := log.LogLevelMapping[logLevelString]
-	if !exist {
-		return nil, fmt.Errorf("General.log-level value invalid")
-	}
 
 	general := &General{
 		Port:               port,
@@ -310,3 +330,78 @@ func parseRules(cfg *rawConfig) ([]C.Rule, error) {
 
 	return rules, nil
 }
+
+func hostWithDefaultPort(host string, defPort string) (string, error) {
+	if !strings.Contains(host, ":") {
+		host += ":"
+	}
+
+	hostname, port, err := net.SplitHostPort(host)
+	if err != nil {
+		return "", err
+	}
+
+	if port == "" {
+		port = defPort
+	}
+
+	return net.JoinHostPort(hostname, port), nil
+}
+
+func parseNameServer(servers []string) ([]dns.NameServer, error) {
+	nameservers := []dns.NameServer{}
+	log.Debugln("%#v", servers)
+
+	for idx, server := range servers {
+		// parse without scheme .e.g 8.8.8.8:53
+		if host, err := hostWithDefaultPort(server, "53"); err == nil {
+			nameservers = append(
+				nameservers,
+				dns.NameServer{Addr: host},
+			)
+			continue
+		}
+
+		u, err := url.Parse(server)
+		if err != nil {
+			return nil, fmt.Errorf("DNS NameServer[%d] format error: %s", idx, err.Error())
+		}
+
+		if u.Scheme != "tls" {
+			return nil, fmt.Errorf("DNS NameServer[%d] unsupport scheme: %s", idx, u.Scheme)
+		}
+
+		host, err := hostWithDefaultPort(u.Host, "853")
+		nameservers = append(
+			nameservers,
+			dns.NameServer{
+				Net:  "tcp-tls",
+				Addr: host,
+			},
+		)
+	}
+
+	return nameservers, nil
+}
+
+func parseDNS(cfg *rawDNS) (*DNS, error) {
+	if cfg.Enable && len(cfg.NameServer) == 0 {
+		return nil, fmt.Errorf("If DNS configuration is turned on, NameServer cannot be empty")
+	}
+
+	dnsCfg := &DNS{
+		Enable:       cfg.Enable,
+		Listen:       cfg.Listen,
+		EnhancedMode: cfg.EnhancedMode,
+	}
+
+	if nameserver, err := parseNameServer(cfg.NameServer); err == nil {
+		dnsCfg.NameServer = nameserver
+	}
+
+	if fallback, err := parseNameServer(cfg.Fallback); err == nil {
+		dnsCfg.Fallback = fallback
+	}
+
+	return dnsCfg, nil
+}

constant/metadata.go

@@ -15,6 +15,7 @@ const (
 
 	HTTP SourceType = iota
 	SOCKS
+	REDIR
 )
 
 type NetWork int

dns/client.go

@@ -0,0 +1,263 @@
+package dns
+
+import (
+	"context"
+	"crypto/tls"
+	"errors"
+	"net"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/Dreamacro/clash/common/cache"
+	"github.com/Dreamacro/clash/common/picker"
+	C "github.com/Dreamacro/clash/constant"
+	"github.com/Dreamacro/clash/log"
+
+	D "github.com/miekg/dns"
+	geoip2 "github.com/oschwald/geoip2-golang"
+)
+
+var (
+	globalSessionCache = tls.NewLRUClientSessionCache(64)
+
+	mmdb     *geoip2.Reader
+	once     sync.Once
+	resolver *Resolver
+)
+
+type Resolver struct {
+	ipv6     bool
+	mapping  bool
+	fallback []*nameserver
+	main     []*nameserver
+	cache    *cache.Cache
+}
+
+type result struct {
+	Msg   *D.Msg
+	Error error
+}
+
+func isIPRequest(q D.Question) bool {
+	if q.Qclass == D.ClassINET && (q.Qtype == D.TypeA || q.Qtype == D.TypeAAAA) {
+		return true
+	}
+	return false
+}
+
+func (r *Resolver) Exchange(m *D.Msg) (msg *D.Msg, err error) {
+	if len(m.Question) == 0 {
+		return nil, errors.New("should have one question at least")
+	}
+
+	q := m.Question[0]
+	cache := r.cache.Get(q.String())
+	if cache != nil {
+		return cache.(*D.Msg).Copy(), nil
+	}
+	defer func() {
+		if msg != nil {
+			putMsgToCache(r.cache, q.String(), msg)
+			if r.mapping {
+				ips, err := r.msgToIP(msg)
+				if err != nil {
+					log.Debugln("[DNS] msg to ip error: %s", err.Error())
+					return
+				}
+				for _, ip := range ips {
+					putMsgToCache(r.cache, ip.String(), msg)
+				}
+			}
+		}
+	}()
+
+	isIPReq := isIPRequest(q)
+	if isIPReq {
+		msg, err = r.resolveIP(m)
+		return
+	}
+
+	msg, err = r.exchange(r.main, m)
+	return
+}
+
+func (r *Resolver) exchange(servers []*nameserver, m *D.Msg) (msg *D.Msg, err error) {
+	in := make(chan interface{})
+	ctx, cancel := context.WithTimeout(context.Background(), time.Second)
+	defer cancel()
+	fast := picker.SelectFast(ctx, in)
+
+	wg := sync.WaitGroup{}
+	wg.Add(len(servers))
+	for _, server := range servers {
+		go func(s *nameserver) {
+			defer wg.Done()
+			msg, _, err := s.Client.Exchange(m, s.Address)
+			if err != nil || msg.Rcode != D.RcodeSuccess {
+				return
+			}
+			in <- &result{Msg: msg, Error: err}
+		}(server)
+	}
+
+	// release in channel
+	go func() {
+		wg.Wait()
+		close(in)
+	}()
+
+	elm, exist := <-fast
+	if !exist {
+		return nil, errors.New("All DNS requests failed")
+	}
+
+	resp := elm.(*result)
+	msg, err = resp.Msg, resp.Error
+	return
+}
+
+func (r *Resolver) resolveIP(m *D.Msg) (msg *D.Msg, err error) {
+	msgCh := r.resolve(r.main, m)
+	if r.fallback == nil {
+		res := <-msgCh
+		msg, err = res.Msg, res.Error
+		return
+	}
+	fallbackMsg := r.resolve(r.fallback, m)
+	res := <-msgCh
+	if res.Error == nil {
+		if mmdb == nil {
+			return nil, errors.New("GeoIP can't use")
+		}
+
+		ips, _ := r.msgToIP(res.Msg)
+		if record, _ := mmdb.Country(ips[0]); record.Country.IsoCode == "CN" || record.Country.IsoCode == "" {
+			// release channel
+			go func() { <-fallbackMsg }()
+			msg = res.Msg
+			return
+		}
+	}
+
+	res = <-fallbackMsg
+	msg, err = res.Msg, res.Error
+	return
+}
+
+func (r *Resolver) ResolveIP(host string) (ip net.IP, err error) {
+	query := &D.Msg{}
+	dnsType := D.TypeA
+	if r.ipv6 {
+		dnsType = D.TypeAAAA
+	}
+	query.SetQuestion(D.Fqdn(host), dnsType)
+
+	msg, err := r.Exchange(query)
+	if err != nil {
+		return nil, err
+	}
+
+	var ips []net.IP
+	ips, err = r.msgToIP(msg)
+	if err != nil {
+		return nil, err
+	}
+
+	ip = ips[0]
+	return
+}
+
+func (r *Resolver) msgToIP(msg *D.Msg) ([]net.IP, error) {
+	var ips []net.IP
+
+	for _, answer := range msg.Answer {
+		if r.ipv6 {
+			ans, ok := answer.(*D.AAAA)
+			if !ok {
+				continue
+			}
+			ips = append(ips, ans.AAAA)
+			continue
+		}
+
+		ans, ok := answer.(*D.A)
+		if !ok {
+			continue
+		}
+		ips = append(ips, ans.A)
+	}
+
+	if len(ips) == 0 {
+		return nil, errors.New("Can't parse msg")
+	}
+
+	return ips, nil
+}
+
+func (r *Resolver) IPToHost(ip net.IP) (string, bool) {
+	cache := r.cache.Get(ip.String())
+	if cache == nil {
+		return "", false
+	}
+	fqdn := cache.(*D.Msg).Question[0].Name
+	return strings.TrimRight(fqdn, "."), true
+}
+
+func (r *Resolver) resolve(client []*nameserver, msg *D.Msg) <-chan *result {
+	ch := make(chan *result)
+	go func() {
+		res, err := r.exchange(client, msg)
+		ch <- &result{Msg: res, Error: err}
+	}()
+	return ch
+}
+
+type NameServer struct {
+	Net  string
+	Addr string
+}
+
+type nameserver struct {
+	Client  *D.Client
+	Address string
+}
+
+type Config struct {
+	Main, Fallback []NameServer
+	IPv6           bool
+	EnhancedMode   EnhancedMode
+}
+
+func transform(servers []NameServer) []*nameserver {
+	var ret []*nameserver
+	for _, s := range servers {
+		ret = append(ret, &nameserver{
+			Client: &D.Client{
+				Net: s.Net,
+				TLSConfig: &tls.Config{
+					ClientSessionCache: globalSessionCache,
+				},
+			},
+			Address: s.Addr,
+		})
+	}
+	return ret
+}
+
+func New(config Config) *Resolver {
+	once.Do(func() {
+		mmdb, _ = geoip2.Open(C.Path.MMDB())
+	})
+
+	r := &Resolver{
+		main:    transform(config.Main),
+		ipv6:    config.IPv6,
+		cache:   cache.New(time.Second * 60),
+		mapping: config.EnhancedMode == MAPPING,
+	}
+	if config.Fallback != nil {
+		r.fallback = transform(config.Fallback)
+	}
+	return r
+}

dns/server.go

@@ -0,0 +1,62 @@
+package dns
+
+import (
+	"net"
+
+	D "github.com/miekg/dns"
+)
+
+var (
+	address string
+	server  = &Server{}
+)
+
+type Server struct {
+	*D.Server
+	r *Resolver
+}
+
+func (s *Server) ServeDNS(w D.ResponseWriter, r *D.Msg) {
+	msg, err := s.r.Exchange(r)
+
+	if err != nil {
+		D.HandleFailed(w, r)
+		return
+	}
+	msg.SetReply(r)
+	w.WriteMsg(msg)
+}
+
+func ReCreateServer(addr string, resolver *Resolver) error {
+	if server.Server != nil {
+		server.Shutdown()
+	}
+
+	if addr == address {
+		return nil
+	}
+
+	_, port, err := net.SplitHostPort(addr)
+	if port == "0" || port == "" || err != nil {
+		return nil
+	}
+
+	udpAddr, err := net.ResolveUDPAddr("udp", addr)
+	if err != nil {
+		return err
+	}
+
+	p, err := net.ListenUDP("udp", udpAddr)
+	if err != nil {
+		return err
+	}
+
+	address = addr
+	server = &Server{r: resolver}
+	server.Server = &D.Server{Addr: addr, PacketConn: p, Handler: server}
+
+	go func() {
+		server.ActivateAndServe()
+	}()
+	return nil
+}

dns/util.go

@@ -0,0 +1,85 @@
+package dns
+
+import (
+	"encoding/json"
+	"errors"
+	"time"
+
+	"github.com/Dreamacro/clash/common/cache"
+	"github.com/Dreamacro/clash/log"
+	yaml "gopkg.in/yaml.v2"
+
+	D "github.com/miekg/dns"
+)
+
+var (
+	// EnhancedModeMapping is a mapping for EnhancedMode enum
+	EnhancedModeMapping = map[string]EnhancedMode{
+		FAKEIP.String():  FAKEIP,
+		MAPPING.String(): MAPPING,
+	}
+)
+
+const (
+	FAKEIP EnhancedMode = iota
+	MAPPING
+)
+
+type EnhancedMode int
+
+// UnmarshalYAML unserialize EnhancedMode with yaml
+func (e *EnhancedMode) UnmarshalYAML(unmarshal func(interface{}) error) error {
+	var tp string
+	if err := unmarshal(&tp); err != nil {
+		return err
+	}
+	mode, exist := EnhancedModeMapping[tp]
+	if !exist {
+		return errors.New("invalid mode")
+	}
+	*e = mode
+	return nil
+}
+
+// MarshalYAML serialize EnhancedMode with yaml
+func (e EnhancedMode) MarshalYAML() ([]byte, error) {
+	return yaml.Marshal(e.String())
+}
+
+// UnmarshalJSON unserialize EnhancedMode with json
+func (e *EnhancedMode) UnmarshalJSON(data []byte) error {
+	var tp string
+	json.Unmarshal(data, &tp)
+	mode, exist := EnhancedModeMapping[tp]
+	if !exist {
+		return errors.New("invalid mode")
+	}
+	*e = mode
+	return nil
+}
+
+// MarshalJSON serialize EnhancedMode with json
+func (e EnhancedMode) MarshalJSON() ([]byte, error) {
+	return json.Marshal(e.String())
+}
+
+func (e EnhancedMode) String() string {
+	switch e {
+	case FAKEIP:
+		return "fakeip"
+	case MAPPING:
+		return "redir-host"
+	default:
+		return "unknown"
+	}
+}
+
+func putMsgToCache(c *cache.Cache, key string, msg *D.Msg) {
+	if len(msg.Answer) == 0 {
+		log.Debugln("[DNS] answer length is zero: %#v", msg)
+		return
+	}
+
+	ttl := time.Duration(msg.Answer[0].Header().Ttl) * time.Second
+	c.Put(key, msg, ttl)
+}

go.mod

@@ -1,17 +1,20 @@
 module github.com/Dreamacro/clash
 
 require (
-	github.com/Dreamacro/go-shadowsocks2 v0.1.2-0.20181019110427-0a03f1a25270
+	github.com/Dreamacro/go-shadowsocks2 v0.1.2
 	github.com/eapache/queue v1.1.0 // indirect
 	github.com/go-chi/chi v3.3.3+incompatible
 	github.com/go-chi/cors v1.0.0
 	github.com/go-chi/render v1.0.1
 	github.com/gofrs/uuid v3.1.0+incompatible
 	github.com/gorilla/websocket v1.4.0
+	github.com/miekg/dns v1.1.0
 	github.com/oschwald/geoip2-golang v1.2.1
 	github.com/oschwald/maxminddb-golang v1.3.0 // indirect
-	github.com/sirupsen/logrus v1.1.0
+	github.com/sirupsen/logrus v1.2.0
-	golang.org/x/crypto v0.0.0-20181009213950-7c1a557ab941
+	golang.org/x/crypto v0.0.0-20181127143415-eb0de9b17e85
+	golang.org/x/net v0.0.0-20181108082009-03003ca0c849 // indirect
+	golang.org/x/sync v0.0.0-20181108010431-42b317875d0f // indirect
 	gopkg.in/eapache/channels.v1 v1.1.0
-	gopkg.in/yaml.v2 v2.2.1
+	gopkg.in/yaml.v2 v2.2.2
 )

go.sum

@@ -1,5 +1,5 @@
-github.com/Dreamacro/go-shadowsocks2 v0.1.2-0.20181019110427-0a03f1a25270 h1:ugkI+Yw5ArFnhF8KTbJxyWIyvxMCa8jWyUF+wIAulhM=
+github.com/Dreamacro/go-shadowsocks2 v0.1.2 h1:8KgWbwAw5PJF+i6F3tI2iW/Em9WDtAuDG4obot8bGLM=
-github.com/Dreamacro/go-shadowsocks2 v0.1.2-0.20181019110427-0a03f1a25270/go.mod h1:DlkXRxmh5K+99aTPQaVjsZ1fAZNFw42vXGcOjR3Otps=
+github.com/Dreamacro/go-shadowsocks2 v0.1.2/go.mod h1:J5YbNUiKtaD7EJmQ4O9ruUTY9+IgrflPgm63K1nUE0I=
 github.com/aead/chacha20 v0.0.0-20180709150244-8b13a72661da h1:KjTM2ks9d14ZYCvmHS9iAKVt9AyzRSqNU1qabPih5BY=
 github.com/aead/chacha20 v0.0.0-20180709150244-8b13a72661da/go.mod h1:eHEWzANqSiWQsof+nXEI9bUVUyV6F53Fp89EuCh2EAA=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
@@ -16,22 +16,28 @@ github.com/gofrs/uuid v3.1.0+incompatible h1:q2rtkjaKT4YEr6E1kamy0Ha4RtepWlQBedy
 github.com/gofrs/uuid v3.1.0+incompatible/go.mod h1:b2aQJv3Z4Fp6yNu3cdSllBxTCLRxnplIgP/c0N/04lM=
 github.com/gorilla/websocket v1.4.0 h1:WDFjx/TMzVgy9VdMMQi2K2Emtwi2QcUQsztZ/zLaH/Q=
 github.com/gorilla/websocket v1.4.0/go.mod h1:E7qHFY5m1UJ88s3WnNqhKjPHQ0heANvMoAMk2YaljkQ=
-github.com/konsorten/go-windows-terminal-sequences v0.0.0-20180402223658-b729f2633dfe h1:CHRGQ8V7OlCYtwaKPJi3iA7J+YdNKdo8j7nG5IgDhjs=
+github.com/konsorten/go-windows-terminal-sequences v1.0.1 h1:mweAR1A6xJ3oS2pRaGiHgQ4OO8tzTaLawm8vnODuwDk=
-github.com/konsorten/go-windows-terminal-sequences v0.0.0-20180402223658-b729f2633dfe/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
+github.com/konsorten/go-windows-terminal-sequences v1.0.1/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
+github.com/miekg/dns v1.1.0 h1:yv9O9RJbvVFkvW8PKYqp4x7HQkc5RWwmUY/L8MdUaIg=
+github.com/miekg/dns v1.1.0/go.mod h1:W1PPwlIAgtquWBMBEV9nkV9Cazfe8ScdGz/Lj7v3Nrg=
 github.com/oschwald/geoip2-golang v1.2.1 h1:3iz+jmeJc6fuCyWeKgtXSXu7+zvkxJbHFXkMT5FVebU=
 github.com/oschwald/geoip2-golang v1.2.1/go.mod h1:0LTTzix/Ao1uMvOhAV4iLU0Lz7eCrP94qZWBTDKf0iE=
 github.com/oschwald/maxminddb-golang v1.3.0 h1:oTh8IBSj10S5JNlUDg5WjJ1QdBMdeaZIkPEVfESSWgE=
 github.com/oschwald/maxminddb-golang v1.3.0/go.mod h1:3jhIUymTJ5VREKyIhWm66LJiQt04F0UCDdodShpjWsY=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
-github.com/sirupsen/logrus v1.1.0 h1:65VZabgUiV9ktjGM5nTq0+YurgTyX+YI2lSSfDjI+qU=
+github.com/sirupsen/logrus v1.2.0 h1:juTguoYk5qI21pwyTXY3B3Y5cOTH3ZUyZCg1v/mihuo=
-github.com/sirupsen/logrus v1.1.0/go.mod h1:zrgwTnHtNr00buQ1vSptGe8m1f/BbgsPukg8qsT7A+A=
+github.com/sirupsen/logrus v1.2.0/go.mod h1:LxeOpSwHxABJmUn/MG1IvRgCAasNZTLOkJPxbbu5VWo=
+github.com/stretchr/objx v0.1.1/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.2.2 h1:bSDNvY7ZPG5RlJ8otE/7V6gMiyenm9RtJ7IUVIAoJ1w=
 github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
 golang.org/x/crypto v0.0.0-20180904163835-0709b304e793/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
-golang.org/x/crypto v0.0.0-20181009213950-7c1a557ab941 h1:qBTHLajHecfu+xzRI9PqVDcqx7SdHj9d4B+EzSn3tAc=
+golang.org/x/crypto v0.0.0-20181127143415-eb0de9b17e85 h1:et7+NAX3lLIk5qUCTA9QelBjGE/NkhzYw/mhnr0s7nI=
-golang.org/x/crypto v0.0.0-20181009213950-7c1a557ab941/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
+golang.org/x/crypto v0.0.0-20181127143415-eb0de9b17e85/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
-golang.org/x/sys v0.0.0-20180905080454-ebe1bf3edb33 h1:I6FyU15t786LL7oL/hn43zqTuEGr4PN7F4XJ1p4E3Y8=
+golang.org/x/net v0.0.0-20181108082009-03003ca0c849 h1:FSqE2GGG7wzsYUsWiQ8MZrvEd1EOyU3NCF0AW3Wtltg=
+golang.org/x/net v0.0.0-20181108082009-03003ca0c849/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
+golang.org/x/sync v0.0.0-20181108010431-42b317875d0f h1:Bl/8QSvNqXvPGPGXa2z5xUTmV7VDcZyvRZ+QQXkXTZQ=
+golang.org/x/sync v0.0.0-20181108010431-42b317875d0f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sys v0.0.0-20180905080454-ebe1bf3edb33/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20181005133103-4497e2df6f9e h1:EfdBzeKbFSvOjoIqSZcfS8wp0FBLokGBEs9lz1OtSg0=
 golang.org/x/sys v0.0.0-20181005133103-4497e2df6f9e/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
@@ -39,5 +45,5 @@ gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/eapache/channels.v1 v1.1.0 h1:5bGAyKKvyCTWjSj7mhefG6Lc68VyN4MH1v8/7OoeeB4=
 gopkg.in/eapache/channels.v1 v1.1.0/go.mod h1:BHIBujSvu9yMTrTYbTCjDD43gUhtmaOtTWDe7sTv1js=
-gopkg.in/yaml.v2 v2.2.1 h1:mUhvW9EsL+naU5Q3cakzfE91YhliOondGd6ZrsDBHQE=
+gopkg.in/yaml.v2 v2.2.2 h1:ZCJp+EgiOT7lHqUV2J862kp8Qj64Jo6az82+3Td9dZw=
-gopkg.in/yaml.v2 v2.2.1/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
+gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=

hub/executor/executor.go

@@ -4,6 +4,7 @@ import (
 	adapters "github.com/Dreamacro/clash/adapters/outbound"
 	"github.com/Dreamacro/clash/config"
 	C "github.com/Dreamacro/clash/constant"
+	"github.com/Dreamacro/clash/dns"
 	"github.com/Dreamacro/clash/log"
 	P "github.com/Dreamacro/clash/proxy"
 	T "github.com/Dreamacro/clash/tunnel"
@@ -26,6 +27,8 @@ func ApplyConfig(cfg *config.Config, force bool) {
 	}
 	updateProxies(cfg.Proxies)
 	updateRules(cfg.Rules)
+	updateGeneral(cfg.General)
+	updateDNS(cfg.DNS)
 }
 
 func GetGeneral() *config.General {
@@ -40,6 +43,22 @@ func GetGeneral() *config.General {
 	}
 }
 
+func updateDNS(c *config.DNS) {
+	if c.Enable == false {
+		T.Instance().SetResolver(nil)
+		dns.ReCreateServer("", nil)
+		return
+	}
+	r := dns.New(dns.Config{
+		Main:         c.NameServer,
+		Fallback:     c.Fallback,
+		IPv6:         c.IPv6,
+		EnhancedMode: c.EnhancedMode,
+	})
+	T.Instance().SetResolver(r)
+	dns.ReCreateServer(c.Listen, r)
+}
+
 func updateProxies(proxies map[string]C.Proxy) {
 	tunnel := T.Instance()
 	oldProxies := tunnel.Proxies()

log/level.go

@@ -3,18 +3,16 @@ package log
 import (
 	"encoding/json"
 	"errors"
-
-	yaml "gopkg.in/yaml.v2"
 )
 
 var (
 	// LogLevelMapping is a mapping for LogLevel enum
 	LogLevelMapping = map[string]LogLevel{
-		"error":   ERROR,
+		ERROR.String():   ERROR,
-		"warning": WARNING,
+		WARNING.String(): WARNING,
-		"info":    INFO,
+		INFO.String():    INFO,
-		"debug":   DEBUG,
+		DEBUG.String():   DEBUG,
-		"silent":  SILENT,
+		SILENT.String():  SILENT,
 	}
 )
 
@@ -28,10 +26,10 @@ const (
 
 type LogLevel int
 
-// UnmarshalYAML unserialize Mode with yaml
+// UnmarshalYAML unserialize LogLevel with yaml
-func (l *LogLevel) UnmarshalYAML(data []byte) error {
+func (l *LogLevel) UnmarshalYAML(unmarshal func(interface{}) error) error {
 	var tp string
-	yaml.Unmarshal(data, &tp)
+	unmarshal(&tp)
 	level, exist := LogLevelMapping[tp]
 	if !exist {
 		return errors.New("invalid mode")
@@ -40,12 +38,7 @@ func (l *LogLevel) UnmarshalYAML(data []byte) error {
 	return nil
 }
 
-// MarshalYAML serialize Mode with yaml
+// UnmarshalJSON unserialize LogLevel with json
-func (l LogLevel) MarshalYAML() ([]byte, error) {
-	return yaml.Marshal(l.String())
-}
-
-// UnmarshalJSON unserialize Mode with json
 func (l *LogLevel) UnmarshalJSON(data []byte) error {
 	var tp string
 	json.Unmarshal(data, &tp)
@@ -57,7 +50,7 @@ func (l *LogLevel) UnmarshalJSON(data []byte) error {
 	return nil
 }
 
-// MarshalJSON serialize Mode with json
+// MarshalJSON serialize LogLevel with json
 func (l LogLevel) MarshalJSON() ([]byte, error) {
 	return json.Marshal(l.String())
 }
@@ -75,6 +68,6 @@ func (l LogLevel) String() string {
 	case SILENT:
 		return "silent"
 	default:
-		return "unknow"
+		return "unknown"
 	}
 }

log/log.go

@@ -14,6 +14,10 @@ var (
 	level  = INFO
 )
 
+func init() {
+	log.SetLevel(log.DebugLevel)
+}
+
 type Event struct {
 	LogLevel LogLevel
 	Payload  string
@@ -47,6 +51,10 @@ func Debugln(format string, v ...interface{}) {
 	print(event)
 }
 
+func Fatalln(format string, v ...interface{}) {
+	log.Fatalf(format, v...)
+}
+
 func Subscribe() observable.Subscription {
 	sub, _ := source.Subscribe()
 	return sub

proxy/http/server.go

@@ -14,18 +14,18 @@ var (
 	tun = tunnel.Instance()
 )
 
-type httpListener struct {
+type HttpListener struct {
 	net.Listener
 	address string
 	closed  bool
 }
 
-func NewHttpProxy(addr string) (*httpListener, error) {
+func NewHttpProxy(addr string) (*HttpListener, error) {
 	l, err := net.Listen("tcp", addr)
 	if err != nil {
 		return nil, err
 	}
-	hl := &httpListener{l, addr, false}
+	hl := &HttpListener{l, addr, false}
 
 	go func() {
 		log.Infoln("HTTP proxy listening at: %s", addr)
@@ -44,12 +44,12 @@ func NewHttpProxy(addr string) (*httpListener, error) {
 	return hl, nil
 }
 
-func (l *httpListener) Close() {
+func (l *HttpListener) Close() {
 	l.closed = true
 	l.Listener.Close()
 }
 
-func (l *httpListener) Address() string {
+func (l *HttpListener) Address() string {
 	return l.address
 }
 

proxy/listener.go

@@ -13,9 +13,9 @@ import (
 var (
 	allowLan = false
 
-	socksListener listener
+	socksListener *socks.SockListener
-	httpListener  listener
+	httpListener  *http.HttpListener
-	redirListener listener
+	redirListener *redir.RedirListener
 )
 
 type listener interface {

proxy/redir/tcp.go

@@ -4,6 +4,7 @@ import (
 	"net"
 
 	"github.com/Dreamacro/clash/adapters/inbound"
+	C "github.com/Dreamacro/clash/constant"
 	"github.com/Dreamacro/clash/log"
 	"github.com/Dreamacro/clash/tunnel"
 )
@@ -12,18 +13,18 @@ var (
 	tun = tunnel.Instance()
 )
 
-type redirListener struct {
+type RedirListener struct {
 	net.Listener
 	address string
 	closed  bool
 }
 
-func NewRedirProxy(addr string) (*redirListener, error) {
+func NewRedirProxy(addr string) (*RedirListener, error) {
 	l, err := net.Listen("tcp", addr)
 	if err != nil {
 		return nil, err
 	}
-	rl := &redirListener{l, addr, false}
+	rl := &RedirListener{l, addr, false}
 
 	go func() {
 		log.Infoln("Redir proxy listening at: %s", addr)
@@ -42,12 +43,12 @@ func NewRedirProxy(addr string) (*redirListener, error) {
 	return rl, nil
 }
 
-func (l *redirListener) Close() {
+func (l *RedirListener) Close() {
 	l.closed = true
 	l.Listener.Close()
 }
 
-func (l *redirListener) Address() string {
+func (l *RedirListener) Address() string {
 	return l.address
 }
 
@@ -58,5 +59,5 @@ func handleRedir(conn net.Conn) {
 		return
 	}
 	conn.(*net.TCPConn).SetKeepAlive(true)
-	tun.Add(adapters.NewSocket(target, conn))
+	tun.Add(adapters.NewSocket(target, conn, C.REDIR))
 }

proxy/socks/tcp.go

@@ -4,6 +4,7 @@ import (
 	"net"
 
 	"github.com/Dreamacro/clash/adapters/inbound"
+	C "github.com/Dreamacro/clash/constant"
 	"github.com/Dreamacro/clash/log"
 	"github.com/Dreamacro/clash/tunnel"
 
@@ -14,19 +15,19 @@ var (
 	tun = tunnel.Instance()
 )
 
-type sockListener struct {
+type SockListener struct {
 	net.Listener
 	address string
 	closed  bool
 }
 
-func NewSocksProxy(addr string) (*sockListener, error) {
+func NewSocksProxy(addr string) (*SockListener, error) {
 	l, err := net.Listen("tcp", addr)
 	if err != nil {
 		return nil, err
 	}
 
-	sl := &sockListener{l, addr, false}
+	sl := &SockListener{l, addr, false}
 	go func() {
 		log.Infoln("SOCKS proxy listening at: %s", addr)
 		for {
@@ -44,12 +45,12 @@ func NewSocksProxy(addr string) (*sockListener, error) {
 	return sl, nil
 }
 
-func (l *sockListener) Close() {
+func (l *SockListener) Close() {
 	l.closed = true
 	l.Listener.Close()
 }
 
-func (l *sockListener) Address() string {
+func (l *SockListener) Address() string {
 	return l.address
 }
 
@@ -60,5 +61,5 @@ func handleSocks(conn net.Conn) {
 		return
 	}
 	conn.(*net.TCPConn).SetKeepAlive(true)
-	tun.Add(adapters.NewSocket(target, conn))
+	tun.Add(adapters.NewSocket(target, conn, C.SOCKS))
 }

tunnel/mode.go

@@ -10,9 +10,9 @@ type Mode int
 var (
 	// ModeMapping is a mapping for Mode enum
 	ModeMapping = map[string]Mode{
-		"Global": Global,
+		Global.String(): Global,
-		"Rule":   Rule,
+		Rule.String():   Rule,
-		"Direct": Direct,
+		Direct.String(): Direct,
 	}
 )
 
@@ -34,6 +34,18 @@ func (m *Mode) UnmarshalJSON(data []byte) error {
 	return nil
 }
 
+// UnmarshalYAML unserialize Mode with yaml
+func (m *Mode) UnmarshalYAML(unmarshal func(interface{}) error) error {
+	var tp string
+	unmarshal(&tp)
+	mode, exist := ModeMapping[tp]
+	if !exist {
+		return errors.New("invalid mode")
+	}
+	*m = mode
+	return nil
+}
+
 // MarshalJSON serialize Mode
 func (m Mode) MarshalJSON() ([]byte, error) {
 	return json.Marshal(m.String())

tunnel/tunnel.go

@@ -1,11 +1,13 @@
 package tunnel
 
 import (
+	"net"
 	"sync"
 	"time"
 
 	InboundAdapter "github.com/Dreamacro/clash/adapters/inbound"
 	C "github.com/Dreamacro/clash/constant"
+	"github.com/Dreamacro/clash/dns"
 	"github.com/Dreamacro/clash/log"
 
 	"gopkg.in/eapache/channels.v1"
@@ -23,6 +25,7 @@ type Tunnel struct {
 	proxies    map[string]C.Proxy
 	configLock *sync.RWMutex
 	traffic    *C.Traffic
+	resolver   *dns.Resolver
 
 	// Outbound Rule
 	mode Mode
@@ -72,6 +75,11 @@ func (t *Tunnel) SetMode(mode Mode) {
 	t.mode = mode
 }
 
+// SetResolver change the resolver of tunnel
+func (t *Tunnel) SetResolver(resolver *dns.Resolver) {
+	t.resolver = resolver
+}
+
 func (t *Tunnel) process() {
 	queue := t.queue.Out()
 	for {
@@ -81,10 +89,41 @@ func (t *Tunnel) process() {
 	}
 }
 
+func (t *Tunnel) resolveIP(host string) (net.IP, error) {
+	if t.resolver == nil {
+		ipAddr, err := net.ResolveIPAddr("ip", host)
+		if err != nil {
+			return nil, err
+		}
+
+		return ipAddr.IP, nil
+	}
+
+	return t.resolver.ResolveIP(host)
+}
+
 func (t *Tunnel) handleConn(localConn C.ServerAdapter) {
 	defer localConn.Close()
 	metadata := localConn.Metadata()
 
+	if metadata.Source == C.REDIR && t.resolver != nil {
+		host, exist := t.resolver.IPToHost(*metadata.IP)
+		if exist {
+			metadata.Host = host
+			metadata.AddrType = C.AtypDomainName
+		}
+	} else if metadata.IP == nil && metadata.AddrType == C.AtypDomainName {
+		ip, err := t.resolveIP(metadata.Host)
+		if err != nil {
+			log.Debugln("[DNS] resolve %s error: %s", metadata.Host, err.Error())
+		} else {
+			log.Debugln("[DNS] %s --> %s", metadata.Host, ip.String())
+			metadata.IP = &ip
+		}
+	} else {
+		log.Debugln("[DNS] unknown%#v", metadata)
+	}
+
 	var proxy C.Proxy
 	switch t.mode {
 	case Direct: