Chore: update dependencies

* Fix: HTTP Status Code `100 Continue` support

* Style: code style adjustment

.github/workflows/go.yml

@@ -0,0 +1,21 @@
+name: Go
+on: [push, pull_request]
+jobs:
+
+  build:
+    name: Build
+    runs-on: ubuntu-latest
+    steps:
+
+      - name: Set up Go 1.13
+        uses: actions/setup-go@v1
+        with:
+          go-version: 1.13
+        id: go
+
+      - name: Check out code into the Go module directory
+        uses: actions/checkout@v1
+
+      - name: Get dependencies
+        run: |
+          go test ./...

.gitignore

@@ -14,3 +14,9 @@ bin/*
 
 # dep
 vendor
+
+# GoLand
+.idea/*
+
+# macOS file
+.DS_Store

.travis.yml

@@ -1,7 +1,7 @@
 language: go
 sudo: false
 go:
-  - '1.12'
+  - '1.13'
 install:
   - "go mod download"
 env:

Dockerfile

@@ -1,21 +1,18 @@
-FROM golang:latest as builder
+FROM golang:alpine as builder
 
-RUN wget http://geolite.maxmind.com/download/geoip/database/GeoLite2-Country.tar.gz -O /tmp/GeoLite2-Country.tar.gz && \
+RUN apk add --no-cache make git && \
+    wget http://geolite.maxmind.com/download/geoip/database/GeoLite2-Country.tar.gz -O /tmp/GeoLite2-Country.tar.gz && \
     tar zxvf /tmp/GeoLite2-Country.tar.gz -C /tmp && \
     mv /tmp/GeoLite2-Country_*/GeoLite2-Country.mmdb /Country.mmdb
-
 WORKDIR /clash-src
-
 COPY . /clash-src
-
 RUN go mod download && \
-    GOOS=linux GOARCH=amd64 CGO_ENABLED=0 go build -ldflags '-w -s' -o /clash
+    make linux-amd64 && \
+    mv ./bin/clash-linux-amd64 /clash
 
 FROM alpine:latest
 
 RUN apk add --no-cache ca-certificates
-
 COPY --from=builder /Country.mmdb /root/.config/clash/
 COPY --from=builder /clash /
-
 ENTRYPOINT ["/clash"]

Makefile

@@ -16,7 +16,8 @@ PLATFORM_LIST = \
 	linux-armv8 \
 	linux-mips-softfloat \
 	linux-mips-hardfloat \
-	linux-mipsle \
+	linux-mipsle-softfloat \
+	linux-mipsle-hardfloat \
 	linux-mips64 \
 	linux-mips64le \
 	freebsd-386 \
@@ -55,8 +56,11 @@ linux-mips-softfloat:
 linux-mips-hardfloat:
 	GOARCH=mips GOMIPS=hardfloat GOOS=linux $(GOBUILD) -o $(BINDIR)/$(NAME)-$@
 
-linux-mipsle:
-	GOARCH=mipsle GOOS=linux $(GOBUILD) -o $(BINDIR)/$(NAME)-$@
+linux-mipsle-softfloat:
+	GOARCH=mipsle GOMIPS=softfloat GOOS=linux $(GOBUILD) -o $(BINDIR)/$(NAME)-$@
+
+linux-mipsle-hardfloat:
+	GOARCH=mipsle GOMIPS=hardfloat GOOS=linux $(GOBUILD) -o $(BINDIR)/$(NAME)-$@
 
 linux-mips64:
 	GOARCH=mips64 GOOS=linux $(GOBUILD) -o $(BINDIR)/$(NAME)-$@

README.md

@@ -20,40 +20,39 @@
 
 ## Features
 
-- HTTP/HTTPS and SOCKS protocol
-- Surge like configuration
+- Local HTTP/HTTPS/SOCKS server
+- Surge-like configuration format
 - GeoIP rule support
-- Support Vmess/Shadowsocks/Socks5
-- Support for Netfilter TCP redirect
+- Supports Vmess, Shadowsocks, Snell and SOCKS5 protocol
+- Supports Netfilter TCP redirecting
+- Comprehensive HTTP API
 
 ## Install
 
-You can build from source:
+Clash Requires Go >= 1.13. You can build it from source:
 
 ```sh
-go get -u -v github.com/Dreamacro/clash
+$ go get -u -v github.com/Dreamacro/clash
 ```
 
-Pre-built binaries are available: [release](https://github.com/Dreamacro/clash/releases)
+Pre-built binaries are available here: [release](https://github.com/Dreamacro/clash/releases)
 
-Requires Go >= 1.12.
-
-Checkout Clash version:
+Check Clash version with:
 
 ```sh
-clash -v
+$ clash -v
 ```
 
 ## Daemon
 
-Unfortunately, there is no native elegant way to implement golang's daemon.
+Unfortunately, there is no native and elegant way to implement daemons on Golang.
 
-So we can use third-party daemon tools like pm2, supervisor, and so on.
+So we can use third-party daemon tools like PM2, Supervisor or the like.
 
 In the case of [pm2](https://github.com/Unitech/pm2), we can start the daemon this way:
 
 ```sh
-pm2 start clash
+$ pm2 start clash
 ```
 
 If you have Docker installed, you can run clash directly using `docker-compose`.
@@ -62,19 +61,20 @@ If you have Docker installed, you can run clash directly using `docker-compose`.
 
 ## Config
 
-The default configuration directory is `$HOME/.config/clash`
+The default configuration directory is `$HOME/.config/clash`.
 
-The name of the configuration file is `config.yaml`
+The name of the configuration file is `config.yaml`.
 
-If you want to use another directory, you can use `-d` to control the configuration directory
+If you want to use another directory, use `-d` to control the configuration directory.
 
-For example, you can use the current directory as the configuration directory
+For example, you can use the current directory as the configuration directory:
 
 ```sh
-clash -d .
+$ clash -d .
 ```
 
-Below is a simple demo configuration file:
+<details>
+  <summary>This is an example configuration file</summary>
 
 ```yml
 # port of HTTP
@@ -88,6 +88,12 @@ socks-port: 7891
 
 allow-lan: false
 
+# Only applicable when setting allow-lan to true
+# "*": bind all IP addresses
+# 192.168.122.11: bind a single IPv4 address
+# "[aaaa::a8aa:ff:fe09:57d8]": bind a single IPv6 address
+# bind-address: "*"
+
 # Rule / Global/ Direct (default is Rule)
 mode: Rule
 
@@ -95,7 +101,7 @@ mode: Rule
 # info / warning / error / debug / silent
 log-level: info
 
-# A RESTful API for clash
+# RESTful API for clash
 external-controller: 127.0.0.1:9090
 
 # you can put the static web resource (such as clash-dashboard) to a directory, and clash would serve in `${API}/ui`
@@ -114,6 +120,12 @@ experimental:
 #  - "user1:pass1"
 #  - "user2:pass2"
 
+# # experimental hosts, support wildcard (e.g. *.clash.dev Even *.foo.*.example.com)
+# # static domain has a higher priority than wildcard domain (foo.example.com > *.example.com)
+# hosts:
+#   '*.clash.dev': 127.0.0.1
+#   'alpha.clash.dev': '::1'
+
 # dns:
   # enable: true # set true to enable dns (default is false)
   # ipv6: false # default is false
@@ -126,21 +138,34 @@ experimental:
   #   - https://1.1.1.1/dns-query # dns over https
   # fallback: # concurrent request with nameserver, fallback used when GEOIP country isn't CN
   #   - tcp://1.1.1.1
+  # fallback-filter:
+  #   geoip: true # default
+  #   ipcidr: # ips in these subnets will be considered polluted
+  #     - 240.0.0.0/4
 
 Proxy:
 
 # shadowsocks
-# The types of cipher are consistent with go-shadowsocks2
-# support AEAD_AES_128_GCM AEAD_AES_192_GCM AEAD_AES_256_GCM AEAD_CHACHA20_POLY1305 AES-128-CTR AES-192-CTR AES-256-CTR AES-128-CFB AES-192-CFB AES-256-CFB CHACHA20-IETF XCHACHA20
-# In addition to what go-shadowsocks2 supports, it also supports chacha20 rc4-md5 xchacha20-ietf-poly1305
-- { name: "ss1", type: ss, server: server, port: 443, cipher: AEAD_CHACHA20_POLY1305, password: "password", udp: true }
+# The supported ciphers(encrypt methods):
+#   aes-128-gcm aes-192-gcm aes-256-gcm
+#   aes-128-cfb aes-192-cfb aes-256-cfb
+#   aes-128-ctr aes-192-ctr aes-256-ctr
+#   rc4-md5 chacha20 chacha20-ietf xchacha20
+#   chacha20-ietf-poly1305 xchacha20-ietf-poly1305
+- name: "ss1"
+  type: ss
+  server: server
+  port: 443
+  cipher: chacha20-ietf-poly1305
+  password: "password"
+  # udp: true
 
-# old obfs configuration remove after prerelease
+# old obfs configuration format remove after prerelease
 - name: "ss2"
   type: ss
   server: server
   port: 443
-  cipher: AEAD_CHACHA20_POLY1305
+  cipher: chacha20-ietf-poly1305
   password: "password"
   plugin: obfs
   plugin-opts:
@@ -151,7 +176,7 @@ Proxy:
   type: ss
   server: server
   port: 443
-  cipher: AEAD_CHACHA20_POLY1305
+  cipher: chacha20-ietf-poly1305
   password: "password"
   plugin: v2ray-plugin
   plugin-opts:
@@ -160,52 +185,98 @@ Proxy:
     # skip-cert-verify: true
     # host: bing.com
     # path: "/"
+    # mux: true
     # headers:
     #   custom: value
 
 # vmess
 # cipher support auto/aes-128-gcm/chacha20-poly1305/none
-- { name: "vmess", type: vmess, server: server, port: 443, uuid: uuid, alterId: 32, cipher: auto }
-# with tls
-- { name: "vmess", type: vmess, server: server, port: 443, uuid: uuid, alterId: 32, cipher: auto, tls: true }
-# with tls and skip-cert-verify
-- { name: "vmess", type: vmess, server: server, port: 443, uuid: uuid, alterId: 32, cipher: auto, tls: true, skip-cert-verify: true }
-# with ws-path and ws-headers
-- { name: "vmess", type: vmess, server: server, port: 443, uuid: uuid, alterId: 32, cipher: auto, network: ws, ws-path: /path, ws-headers: { Host: v2ray.com } }
-# with ws + tls
-- { name: "vmess", type: vmess, server: server, port: 443, uuid: uuid, alterId: 32, cipher: auto, network: ws, ws-path: /path, tls: true }
+- name: "vmess"
+  type: vmess
+  server: server
+  port: 443
+  uuid: uuid
+  alterId: 32
+  cipher: auto
+  # udp: true
+  # tls: true
+  # skip-cert-verify: true
+  # network: ws
+  # ws-path: /path
+  # ws-headers:
+  #   Host: v2ray.com
 
 # socks5
-- { name: "socks", type: socks5, server: server, port: 443 }
-# socks5 with authentication
-- { name: "socks", type: socks5, server: server, port: 443, username: "username", password: "password" }
-# with tls
-- { name: "socks", type: socks5, server: server, port: 443, tls: true }
-# with tls and skip-cert-verify
-- { name: "socks", type: socks5, server: server, port: 443, tls: true, skip-cert-verify: true }
+- name: "socks"
+  type: socks5
+  server: server
+  port: 443
+  # username: username
+  # password: password
+  # tls: true
+  # skip-cert-verify: true
+  # udp: true
 
 # http
-- { name: "http", type: http, server: server, port: 443 }
-# http with authentication
-- { name: "http", type: http, server: server, port: 443, username: "username", password: "password" }
-# with tls (https)
-- { name: "http", type: http, server: server, port: 443, tls: true }
-# with tls (https) and skip-cert-verify
-- { name: "http", type: http, server: server, port: 443, tls: true, skip-cert-verify: true }
+- name: "http"
+  type: http
+  server: server
+  port: 443
+  # username: username
+  # password: password
+  # tls: true # https
+  # skip-cert-verify: true
+
+# snell
+- name: "snell"
+  type: snell
+  server: server
+  port: 44046
+  psk: yourpsk
+  # obfs-opts:
+    # mode: http # or tls
+    # host: bing.com
 
 Proxy Group:
 # url-test select which proxy will be used by benchmarking speed to a URL.
-- { name: "auto", type: url-test, proxies: ["ss1", "ss2", "vmess1"], url: "http://www.gstatic.com/generate_204", interval: 300 }
+- name: "auto"
+  type: url-test
+  proxies:
+    - ss1
+    - ss2
+    - vmess1
+  url: 'http://www.gstatic.com/generate_204'
+  interval: 300
 
 # fallback select an available policy by priority. The availability is tested by accessing an URL, just like an auto url-test group.
-- { name: "fallback-auto", type: fallback, proxies: ["ss1", "ss2", "vmess1"], url: "http://www.gstatic.com/generate_204", interval: 300 }
+- name: "fallback-auto"
+  type: fallback
+  proxies:
+    - ss1
+    - ss2
+    - vmess1
+  url: 'http://www.gstatic.com/generate_204'
+  interval: 300
 
 # load-balance: The request of the same eTLD will be dial on the same proxy.
-- { name: "load-balance", type: load-balance, proxies: ["ss1", "ss2", "vmess1"], url: "http://www.gstatic.com/generate_204", interval: 300 }
+- name: "load-balance"
+  type: load-balance
+  proxies:
+    - ss1
+    - ss2
+    - vmess1
+  url: 'http://www.gstatic.com/generate_204'
+  interval: 300
 
 # select is used for selecting proxy or proxy group
 # you can use RESTful API to switch proxy, is recommended for use in GUI.
-- { name: "Proxy", type: select, proxies: ["ss1", "ss2", "vmess1", "auto"] }
+- name: Proxy
+  type: select
+  proxies:
+    - ss1
+    - ss2
+    - vmess1
+    - auto
 
 Rule:
 - DOMAIN-SUFFIX,google.com,auto
@@ -222,6 +293,7 @@ Rule:
 # you also can use `FINAL,Proxy` or `FINAL,,Proxy` now
 - MATCH,auto
 ```
+</details>
 
 ## Documentations
 https://clash.gitbook.io/

adapters/outbound/base.go

@@ -1,6 +1,7 @@
 package adapters
 
 import (
+	"context"
 	"encoding/json"
 	"errors"
 	"net"
@@ -11,6 +12,10 @@ import (
 	C "github.com/Dreamacro/clash/constant"
 )
 
+var (
+	defaultURLTestTimeout = time.Second * 5
+)
+
 type Base struct {
 	name string
 	tp   C.AdapterType
@@ -25,7 +30,7 @@ func (b *Base) Type() C.AdapterType {
 	return b.tp
 }
 
-func (b *Base) DialUDP(metadata *C.Metadata) (net.PacketConn, net.Addr, error) {
+func (b *Base) DialUDP(metadata *C.Metadata) (C.PacketConn, net.Addr, error) {
 	return nil, nil, errors.New("no support")
 }
 
@@ -41,6 +46,40 @@ func (b *Base) MarshalJSON() ([]byte, error) {
 	})
 }
 
+type conn struct {
+	net.Conn
+	chain C.Chain
+}
+
+func (c *conn) Chains() C.Chain {
+	return c.chain
+}
+
+func (c *conn) AppendToChains(a C.ProxyAdapter) {
+	c.chain = append(c.chain, a.Name())
+}
+
+func newConn(c net.Conn, a C.ProxyAdapter) C.Conn {
+	return &conn{c, []string{a.Name()}}
+}
+
+type packetConn struct {
+	net.PacketConn
+	chain C.Chain
+}
+
+func (c *packetConn) Chains() C.Chain {
+	return c.chain
+}
+
+func (c *packetConn) AppendToChains(a C.ProxyAdapter) {
+	c.chain = append(c.chain, a.Name())
+}
+
+func newPacketConn(c net.PacketConn, a C.ProxyAdapter) C.PacketConn {
+	return &packetConn{c, []string{a.Name()}}
+}
+
 type Proxy struct {
 	C.ProxyAdapter
 	history *queue.Queue
@@ -51,8 +90,14 @@ func (p *Proxy) Alive() bool {
 	return p.alive
 }
 
-func (p *Proxy) Dial(metadata *C.Metadata) (net.Conn, error) {
-	conn, err := p.ProxyAdapter.Dial(metadata)
+func (p *Proxy) Dial(metadata *C.Metadata) (C.Conn, error) {
+	ctx, cancel := context.WithTimeout(context.Background(), tcpTimeout)
+	defer cancel()
+	return p.DialContext(ctx, metadata)
+}
+
+func (p *Proxy) DialContext(ctx context.Context, metadata *C.Metadata) (C.Conn, error) {
+	conn, err := p.ProxyAdapter.DialContext(ctx, metadata)
 	if err != nil {
 		p.alive = false
 	}
@@ -68,18 +113,18 @@ func (p *Proxy) DelayHistory() []C.DelayHistory {
 	return histories
 }
 
-// LastDelay return last history record. if proxy is not alive, return the max value of int16.
+// LastDelay return last history record. if proxy is not alive, return the max value of uint16.
 func (p *Proxy) LastDelay() (delay uint16) {
 	var max uint16 = 0xffff
 	if !p.alive {
 		return max
 	}
 
-	head := p.history.First()
-	if head == nil {
+	last := p.history.Last()
+	if last == nil {
 		return max
 	}
-	history := head.(C.DelayHistory)
+	history := last.(C.DelayHistory)
 	if history.Delay == 0 {
 		return max
 	}
@@ -99,7 +144,7 @@ func (p *Proxy) MarshalJSON() ([]byte, error) {
 }
 
 // URLTest get the delay for the specified URL
-func (p *Proxy) URLTest(url string) (t uint16, err error) {
+func (p *Proxy) URLTest(ctx context.Context, url string) (t uint16, err error) {
 	defer func() {
 		p.alive = err == nil
 		record := C.DelayHistory{Time: time.Now()}
@@ -118,11 +163,18 @@ func (p *Proxy) URLTest(url string) (t uint16, err error) {
 	}
 
 	start := time.Now()
-	instance, err := p.Dial(&addr)
+	instance, err := p.DialContext(ctx, &addr)
 	if err != nil {
 		return
 	}
 	defer instance.Close()
+
+	req, err := http.NewRequest(http.MethodHead, url, nil)
+	if err != nil {
+		return
+	}
+	req = req.WithContext(ctx)
+
 	transport := &http.Transport{
 		Dial: func(string, string) (net.Conn, error) {
 			return instance, nil
@@ -133,8 +185,9 @@ func (p *Proxy) URLTest(url string) (t uint16, err error) {
 		TLSHandshakeTimeout:   10 * time.Second,
 		ExpectContinueTimeout: 1 * time.Second,
 	}
+
 	client := http.Client{Transport: transport}
-	resp, err := client.Get(url)
+	resp, err := client.Do(req)
 	if err != nil {
 		return
 	}
@@ -146,3 +199,9 @@ func (p *Proxy) URLTest(url string) (t uint16, err error) {
 func NewProxy(adapter C.ProxyAdapter) *Proxy {
 	return &Proxy{adapter, queue.New(10), true}
 }
+
+// ProxyGroupOption contain the common options for all kind of ProxyGroup
+type ProxyGroupOption struct {
+	Name    string   `proxy:"name"`
+	Proxies []string `proxy:"proxies"`
+}

adapters/outbound/direct.go

@@ -1,6 +1,7 @@
 package adapters
 
 import (
+	"context"
 	"net"
 
 	C "github.com/Dreamacro/clash/constant"
@@ -10,31 +11,31 @@ type Direct struct {
 	*Base
 }
 
-func (d *Direct) Dial(metadata *C.Metadata) (net.Conn, error) {
+func (d *Direct) DialContext(ctx context.Context, metadata *C.Metadata) (C.Conn, error) {
 	address := net.JoinHostPort(metadata.Host, metadata.DstPort)
 	if metadata.DstIP != nil {
 		address = net.JoinHostPort(metadata.DstIP.String(), metadata.DstPort)
 	}
 
-	c, err := dialTimeout("tcp", address, tcpTimeout)
+	c, err := dialContext(ctx, "tcp", address)
 	if err != nil {
 		return nil, err
 	}
 	tcpKeepAlive(c)
-	return c, nil
+	return newConn(c, d), nil
 }
 
-func (d *Direct) DialUDP(metadata *C.Metadata) (net.PacketConn, net.Addr, error) {
+func (d *Direct) DialUDP(metadata *C.Metadata) (C.PacketConn, net.Addr, error) {
 	pc, err := net.ListenPacket("udp", "")
 	if err != nil {
 		return nil, nil, err
 	}
 
-	addr, err := resolveUDPAddr("udp", net.JoinHostPort(metadata.String(), metadata.DstPort))
+	addr, err := resolveUDPAddr("udp", metadata.RemoteAddress())
 	if err != nil {
 		return nil, nil, err
 	}
-	return pc, addr, nil
+	return newPacketConn(pc, d), addr, nil
 }
 
 func NewDirect() *Direct {

adapters/outbound/fallback.go

@@ -1,6 +1,7 @@
 package adapters
 
 import (
+	"context"
 	"encoding/json"
 	"errors"
 	"net"
@@ -30,14 +31,22 @@ func (f *Fallback) Now() string {
 	return proxy.Name()
 }
 
-func (f *Fallback) Dial(metadata *C.Metadata) (net.Conn, error) {
+func (f *Fallback) DialContext(ctx context.Context, metadata *C.Metadata) (C.Conn, error) {
 	proxy := f.findAliveProxy()
-	return proxy.Dial(metadata)
+	c, err := proxy.DialContext(ctx, metadata)
+	if err == nil {
+		c.AppendToChains(f)
+	}
+	return c, err
 }
 
-func (f *Fallback) DialUDP(metadata *C.Metadata) (net.PacketConn, net.Addr, error) {
+func (f *Fallback) DialUDP(metadata *C.Metadata) (C.PacketConn, net.Addr, error) {
 	proxy := f.findAliveProxy()
-	return proxy.DialUDP(metadata)
+	pc, addr, err := proxy.DialUDP(metadata)
+	if err == nil {
+		pc.AppendToChains(f)
+	}
+	return pc, addr, err
 }
 
 func (f *Fallback) SupportUDP() bool {
@@ -90,7 +99,7 @@ func (f *Fallback) validTest() {
 
 	for _, p := range f.proxies {
 		go func(p C.Proxy) {
-			p.URLTest(f.rawURL)
+			p.URLTest(context.Background(), f.rawURL)
 			wg.Done()
 		}(p)
 	}

adapters/outbound/http.go

@@ -3,6 +3,7 @@ package adapters
 import (
 	"bufio"
 	"bytes"
+	"context"
 	"crypto/tls"
 	"encoding/base64"
 	"errors"
@@ -35,8 +36,8 @@ type HttpOption struct {
 	SkipCertVerify bool   `proxy:"skip-cert-verify,omitempty"`
 }
 
-func (h *Http) Dial(metadata *C.Metadata) (net.Conn, error) {
-	c, err := dialTimeout("tcp", h.addr, tcpTimeout)
+func (h *Http) DialContext(ctx context.Context, metadata *C.Metadata) (C.Conn, error) {
+	c, err := dialContext(ctx, "tcp", h.addr)
 	if err == nil && h.tls {
 		cc := tls.Client(c, h.tlsConfig)
 		err = cc.Handshake()
@@ -51,14 +52,14 @@ func (h *Http) Dial(metadata *C.Metadata) (net.Conn, error) {
 		return nil, err
 	}
 
-	return c, nil
+	return newConn(c, h), nil
 }
 
 func (h *Http) shakeHand(metadata *C.Metadata, rw io.ReadWriter) error {
 	var buf bytes.Buffer
 	var err error
 
-	addr := net.JoinHostPort(metadata.String(), metadata.DstPort)
+	addr := metadata.RemoteAddress()
 	buf.WriteString("CONNECT " + addr + " HTTP/1.1\r\n")
 	buf.WriteString("Host: " + metadata.String() + "\r\n")
 	buf.WriteString("Proxy-Connection: Keep-Alive\r\n")
@@ -81,17 +82,21 @@ func (h *Http) shakeHand(metadata *C.Metadata, rw io.ReadWriter) error {
 		return err
 	}
 
-	if resp.StatusCode == 200 {
+	if resp.StatusCode == http.StatusOK {
 		return nil
 	}
 
-	if resp.StatusCode == 407 {
+	if resp.StatusCode == http.StatusProxyAuthRequired {
 		return errors.New("HTTP need auth")
 	}
 
-	if resp.StatusCode == 405 {
+	if resp.StatusCode == http.StatusMethodNotAllowed {
 		return errors.New("CONNECT method not allowed by proxy")
 	}
+
+	if resp.StatusCode >= http.StatusInternalServerError {
+		return errors.New(resp.Status)
+	}
 	return fmt.Errorf("can not connect remote err code: %d", resp.StatusCode)
 }
 

adapters/outbound/loadbalance.go

@@ -1,6 +1,7 @@
 package adapters
 
 import (
+	"context"
 	"encoding/json"
 	"errors"
 	"net"
@@ -53,21 +54,34 @@ func jumpHash(key uint64, buckets int32) int32 {
 	return int32(b)
 }
 
-func (lb *LoadBalance) Dial(metadata *C.Metadata) (net.Conn, error) {
+func (lb *LoadBalance) DialContext(ctx context.Context, metadata *C.Metadata) (c C.Conn, err error) {
+	defer func() {
+		if err == nil {
+			c.AppendToChains(lb)
+		}
+	}()
+
 	key := uint64(murmur3.Sum32([]byte(getKey(metadata))))
 	buckets := int32(len(lb.proxies))
 	for i := 0; i < lb.maxRetry; i, key = i+1, key+1 {
 		idx := jumpHash(key, buckets)
 		proxy := lb.proxies[idx]
 		if proxy.Alive() {
-			return proxy.Dial(metadata)
+			c, err = proxy.DialContext(ctx, metadata)
+			return
 		}
 	}
-
-	return lb.proxies[0].Dial(metadata)
+	c, err = lb.proxies[0].DialContext(ctx, metadata)
+	return
 }
 
-func (lb *LoadBalance) DialUDP(metadata *C.Metadata) (net.PacketConn, net.Addr, error) {
+func (lb *LoadBalance) DialUDP(metadata *C.Metadata) (pc C.PacketConn, addr net.Addr, err error) {
+	defer func() {
+		if err == nil {
+			pc.AppendToChains(lb)
+		}
+	}()
+
 	key := uint64(murmur3.Sum32([]byte(getKey(metadata))))
 	buckets := int32(len(lb.proxies))
 	for i := 0; i < lb.maxRetry; i, key = i+1, key+1 {
@@ -95,7 +109,7 @@ func (lb *LoadBalance) validTest() {
 
 	for _, p := range lb.proxies {
 		go func(p C.Proxy) {
-			p.URLTest(lb.rawURL)
+			p.URLTest(context.Background(), lb.rawURL)
 			wg.Done()
 		}(p)
 	}

adapters/outbound/reject.go

@@ -1,6 +1,7 @@
 package adapters
 
 import (
+	"context"
 	"io"
 	"net"
 	"time"
@@ -12,8 +13,8 @@ type Reject struct {
 	*Base
 }
 
-func (r *Reject) Dial(metadata *C.Metadata) (net.Conn, error) {
-	return &NopConn{}, nil
+func (r *Reject) DialContext(ctx context.Context, metadata *C.Metadata) (C.Conn, error) {
+	return newConn(&NopConn{}, r), nil
 }
 
 func NewReject() *Reject {

adapters/outbound/selector.go

@@ -1,6 +1,7 @@
 package adapters
 
 import (
+	"context"
 	"encoding/json"
 	"errors"
 	"net"
@@ -20,12 +21,20 @@ type SelectorOption struct {
 	Proxies []string `proxy:"proxies"`
 }
 
-func (s *Selector) Dial(metadata *C.Metadata) (net.Conn, error) {
-	return s.selected.Dial(metadata)
+func (s *Selector) DialContext(ctx context.Context, metadata *C.Metadata) (C.Conn, error) {
+	c, err := s.selected.DialContext(ctx, metadata)
+	if err == nil {
+		c.AppendToChains(s)
+	}
+	return c, err
 }
 
-func (s *Selector) DialUDP(metadata *C.Metadata) (net.PacketConn, net.Addr, error) {
-	return s.selected.DialUDP(metadata)
+func (s *Selector) DialUDP(metadata *C.Metadata) (C.PacketConn, net.Addr, error) {
+	pc, addr, err := s.selected.DialUDP(metadata)
+	if err == nil {
+		pc.AppendToChains(s)
+	}
+	return pc, addr, err
 }
 
 func (s *Selector) SupportUDP() bool {

adapters/outbound/shadowsocks.go

@@ -1,13 +1,13 @@
 package adapters
 
 import (
+	"context"
 	"crypto/tls"
 	"encoding/json"
 	"fmt"
 	"net"
 	"strconv"
 
-	"github.com/Dreamacro/clash/common/pool"
 	"github.com/Dreamacro/clash/common/structure"
 	obfs "github.com/Dreamacro/clash/component/simple-obfs"
 	"github.com/Dreamacro/clash/component/socks5"
@@ -23,9 +23,9 @@ type ShadowSocks struct {
 	cipher core.Cipher
 
 	// obfs
-	obfsMode   string
-	obfsOption *simpleObfsOption
-	wsOption   *v2rayObfs.WebsocketOption
+	obfsMode    string
+	obfsOption  *simpleObfsOption
+	v2rayOption *v2rayObfs.Option
 }
 
 type ShadowSocksOption struct {
@@ -55,10 +55,11 @@ type v2rayObfsOption struct {
 	TLS            bool              `obfs:"tls,omitempty"`
 	Headers        map[string]string `obfs:"headers,omitempty"`
 	SkipCertVerify bool              `obfs:"skip-cert-verify,omitempty"`
+	Mux            bool              `obfs:"mux,omitempty"`
 }
 
-func (ss *ShadowSocks) Dial(metadata *C.Metadata) (net.Conn, error) {
-	c, err := dialTimeout("tcp", ss.server, tcpTimeout)
+func (ss *ShadowSocks) DialContext(ctx context.Context, metadata *C.Metadata) (C.Conn, error) {
+	c, err := dialContext(ctx, "tcp", ss.server)
 	if err != nil {
 		return nil, fmt.Errorf("%s connect error: %s", ss.server, err.Error())
 	}
@@ -71,17 +72,17 @@ func (ss *ShadowSocks) Dial(metadata *C.Metadata) (net.Conn, error) {
 		c = obfs.NewHTTPObfs(c, ss.obfsOption.Host, port)
 	case "websocket":
 		var err error
-		c, err = v2rayObfs.NewWebsocketObfs(c, ss.wsOption)
+		c, err = v2rayObfs.NewV2rayObfs(c, ss.v2rayOption)
 		if err != nil {
 			return nil, fmt.Errorf("%s connect error: %s", ss.server, err.Error())
 		}
 	}
 	c = ss.cipher.StreamConn(c)
 	_, err = c.Write(serializesSocksAddr(metadata))
-	return c, err
+	return newConn(c, ss), err
 }
 
-func (ss *ShadowSocks) DialUDP(metadata *C.Metadata) (net.PacketConn, net.Addr, error) {
+func (ss *ShadowSocks) DialUDP(metadata *C.Metadata) (C.PacketConn, net.Addr, error) {
 	pc, err := net.ListenPacket("udp", "")
 	if err != nil {
 		return nil, nil, err
@@ -92,13 +93,13 @@ func (ss *ShadowSocks) DialUDP(metadata *C.Metadata) (net.PacketConn, net.Addr,
 		return nil, nil, err
 	}
 
-	remoteAddr, err := net.ResolveUDPAddr("udp", net.JoinHostPort(metadata.String(), metadata.DstPort))
-	if err != nil {
-		return nil, nil, err
+	targetAddr := socks5.ParseAddr(metadata.RemoteAddress())
+	if targetAddr == nil {
+		return nil, nil, fmt.Errorf("parse address error: %v:%v", metadata.String(), metadata.DstPort)
 	}
 
 	pc = ss.cipher.PacketConn(pc)
-	return &ssUDPConn{PacketConn: pc, rAddr: remoteAddr}, addr, nil
+	return newPacketConn(&ssUDPConn{PacketConn: pc, rAddr: targetAddr}, ss), addr, nil
 }
 
 func (ss *ShadowSocks) MarshalJSON() ([]byte, error) {
@@ -116,7 +117,7 @@ func NewShadowSocks(option ShadowSocksOption) (*ShadowSocks, error) {
 		return nil, fmt.Errorf("ss %s initialize error: %s", server, err.Error())
 	}
 
-	var wsOption *v2rayObfs.WebsocketOption
+	var v2rayOption *v2rayObfs.Option
 	var obfsOption *simpleObfsOption
 	obfsMode := ""
 
@@ -144,7 +145,7 @@ func NewShadowSocks(option ShadowSocksOption) (*ShadowSocks, error) {
 		obfsMode = opts.Mode
 		obfsOption = &opts
 	} else if option.Plugin == "v2ray-plugin" {
-		opts := v2rayObfsOption{Host: "bing.com"}
+		opts := v2rayObfsOption{Host: "bing.com", Mux: true}
 		if err := decoder.Decode(option.PluginOpts, &opts); err != nil {
 			return nil, fmt.Errorf("ss %s initialize v2ray-plugin error: %s", server, err.Error())
 		}
@@ -162,11 +163,12 @@ func NewShadowSocks(option ShadowSocksOption) (*ShadowSocks, error) {
 				ClientSessionCache: getClientSessionCache(),
 			}
 		}
-		wsOption = &v2rayObfs.WebsocketOption{
+		v2rayOption = &v2rayObfs.Option{
 			Host:      opts.Host,
 			Path:      opts.Path,
 			Headers:   opts.Headers,
 			TLSConfig: tlsConfig,
+			Mux:       opts.Mux,
 		}
 	}
 
@@ -179,24 +181,23 @@ func NewShadowSocks(option ShadowSocksOption) (*ShadowSocks, error) {
 		server: server,
 		cipher: ciph,
 
-		obfsMode:   obfsMode,
-		wsOption:   wsOption,
-		obfsOption: obfsOption,
+		obfsMode:    obfsMode,
+		v2rayOption: v2rayOption,
+		obfsOption:  obfsOption,
 	}, nil
 }
 
 type ssUDPConn struct {
 	net.PacketConn
-	rAddr net.Addr
+	rAddr socks5.Addr
 }
 
-func (uc *ssUDPConn) WriteTo(b []byte, addr net.Addr) (int, error) {
-	buf := pool.BufPool.Get().([]byte)
-	defer pool.BufPool.Put(buf[:cap(buf)])
-	rAddr := socks5.ParseAddr(uc.rAddr.String())
-	copy(buf[len(rAddr):], b)
-	copy(buf, rAddr)
-	return uc.PacketConn.WriteTo(buf[:len(rAddr)+len(b)], addr)
+func (uc *ssUDPConn) WriteTo(b []byte, addr net.Addr) (n int, err error) {
+	packet, err := socks5.EncodeUDPPacket(uc.rAddr, b)
+	if err != nil {
+		return
+	}
+	return uc.PacketConn.WriteTo(packet[3:], addr)
 }
 
 func (uc *ssUDPConn) ReadFrom(b []byte) (int, net.Addr, error) {

adapters/outbound/snell.go

@@ -0,0 +1,72 @@
+package adapters
+
+import (
+	"context"
+	"fmt"
+	"net"
+	"strconv"
+
+	"github.com/Dreamacro/clash/common/structure"
+	obfs "github.com/Dreamacro/clash/component/simple-obfs"
+	"github.com/Dreamacro/clash/component/snell"
+	C "github.com/Dreamacro/clash/constant"
+)
+
+type Snell struct {
+	*Base
+	server     string
+	psk        []byte
+	obfsOption *simpleObfsOption
+}
+
+type SnellOption struct {
+	Name     string                 `proxy:"name"`
+	Server   string                 `proxy:"server"`
+	Port     int                    `proxy:"port"`
+	Psk      string                 `proxy:"psk"`
+	ObfsOpts map[string]interface{} `proxy:"obfs-opts,omitempty"`
+}
+
+func (s *Snell) DialContext(ctx context.Context, metadata *C.Metadata) (C.Conn, error) {
+	c, err := dialContext(ctx, "tcp", s.server)
+	if err != nil {
+		return nil, fmt.Errorf("%s connect error: %s", s.server, err.Error())
+	}
+	tcpKeepAlive(c)
+	switch s.obfsOption.Mode {
+	case "tls":
+		c = obfs.NewTLSObfs(c, s.obfsOption.Host)
+	case "http":
+		_, port, _ := net.SplitHostPort(s.server)
+		c = obfs.NewHTTPObfs(c, s.obfsOption.Host, port)
+	}
+	c = snell.StreamConn(c, s.psk)
+	port, _ := strconv.Atoi(metadata.DstPort)
+	err = snell.WriteHeader(c, metadata.String(), uint(port))
+	return newConn(c, s), err
+}
+
+func NewSnell(option SnellOption) (*Snell, error) {
+	server := net.JoinHostPort(option.Server, strconv.Itoa(option.Port))
+	psk := []byte(option.Psk)
+
+	decoder := structure.NewDecoder(structure.Option{TagName: "obfs", WeaklyTypedInput: true})
+	obfsOption := &simpleObfsOption{Host: "bing.com"}
+	if err := decoder.Decode(option.ObfsOpts, obfsOption); err != nil {
+		return nil, fmt.Errorf("snell %s initialize obfs error: %s", server, err.Error())
+	}
+
+	if obfsOption.Mode != "tls" && obfsOption.Mode != "http" {
+		return nil, fmt.Errorf("snell %s obfs mode error: %s", server, obfsOption.Mode)
+	}
+
+	return &Snell{
+		Base: &Base{
+			name: option.Name,
+			tp:   C.Snell,
+		},
+		server:     server,
+		psk:        psk,
+		obfsOption: obfsOption,
+	}, nil
+}

adapters/outbound/socks5.go

@@ -1,8 +1,11 @@
 package adapters
 
 import (
+	"context"
 	"crypto/tls"
 	"fmt"
+	"io"
+	"io/ioutil"
 	"net"
 	"strconv"
 
@@ -31,8 +34,8 @@ type Socks5Option struct {
 	SkipCertVerify bool   `proxy:"skip-cert-verify,omitempty"`
 }
 
-func (ss *Socks5) Dial(metadata *C.Metadata) (net.Conn, error) {
-	c, err := dialTimeout("tcp", ss.addr, tcpTimeout)
+func (ss *Socks5) DialContext(ctx context.Context, metadata *C.Metadata) (C.Conn, error) {
+	c, err := dialContext(ctx, "tcp", ss.addr)
 
 	if err == nil && ss.tls {
 		cc := tls.Client(c, ss.tlsConfig)
@@ -51,24 +54,33 @@ func (ss *Socks5) Dial(metadata *C.Metadata) (net.Conn, error) {
 			Password: ss.pass,
 		}
 	}
-	if err := socks5.ClientHandshake(c, serializesSocksAddr(metadata), socks5.CmdConnect, user); err != nil {
+	if _, err := socks5.ClientHandshake(c, serializesSocksAddr(metadata), socks5.CmdConnect, user); err != nil {
 		return nil, err
 	}
-	return c, nil
+	return newConn(c, ss), nil
 }
 
-func (ss *Socks5) DialUDP(metadata *C.Metadata) (net.PacketConn, net.Addr, error) {
-	c, err := dialTimeout("tcp", ss.addr, tcpTimeout)
+func (ss *Socks5) DialUDP(metadata *C.Metadata) (_ C.PacketConn, _ net.Addr, err error) {
+	ctx, cancel := context.WithTimeout(context.Background(), tcpTimeout)
+	defer cancel()
+	c, err := dialContext(ctx, "tcp", ss.addr)
+	if err != nil {
+		err = fmt.Errorf("%s connect error", ss.addr)
+		return
+	}
 
-	if err == nil && ss.tls {
+	if ss.tls {
 		cc := tls.Client(c, ss.tlsConfig)
 		err = cc.Handshake()
 		c = cc
 	}
 
-	if err != nil {
-		return nil, nil, fmt.Errorf("%s connect error", ss.addr)
-	}
+	defer func() {
+		if err != nil {
+			c.Close()
+		}
+	}()
+
 	tcpKeepAlive(c)
 	var user *socks5.User
 	if ss.user != "" {
@@ -78,10 +90,36 @@ func (ss *Socks5) DialUDP(metadata *C.Metadata) (net.PacketConn, net.Addr, error
 		}
 	}
 
-	if err := socks5.ClientHandshake(c, serializesSocksAddr(metadata), socks5.CmdUDPAssociate, user); err != nil {
-		return nil, nil, err
+	bindAddr, err := socks5.ClientHandshake(c, serializesSocksAddr(metadata), socks5.CmdUDPAssociate, user)
+	if err != nil {
+		err = fmt.Errorf("%v client hanshake error", err)
+		return
 	}
-	return &fakeUDPConn{Conn: c}, c.LocalAddr(), nil
+
+	addr, err := net.ResolveUDPAddr("udp", bindAddr.String())
+	if err != nil {
+		return
+	}
+
+	targetAddr := socks5.ParseAddr(metadata.RemoteAddress())
+	if targetAddr == nil {
+		return nil, nil, fmt.Errorf("parse address error: %v:%v", metadata.String(), metadata.DstPort)
+	}
+
+	pc, err := net.ListenPacket("udp", "")
+	if err != nil {
+		return
+	}
+
+	go func() {
+		io.Copy(ioutil.Discard, c)
+		c.Close()
+		// A UDP association terminates when the TCP connection that the UDP
+		// ASSOCIATE request arrived on terminates. RFC1928
+		pc.Close()
+	}()
+
+	return newPacketConn(&socksUDPConn{PacketConn: pc, rAddr: targetAddr, tcpConn: c}, ss), addr, nil
 }
 
 func NewSocks5(option Socks5Option) *Socks5 {
@@ -108,3 +146,37 @@ func NewSocks5(option Socks5Option) *Socks5 {
 		tlsConfig:      tlsConfig,
 	}
 }
+
+type socksUDPConn struct {
+	net.PacketConn
+	rAddr   socks5.Addr
+	tcpConn net.Conn
+}
+
+func (uc *socksUDPConn) WriteTo(b []byte, addr net.Addr) (n int, err error) {
+	packet, err := socks5.EncodeUDPPacket(uc.rAddr, b)
+	if err != nil {
+		return
+	}
+	return uc.PacketConn.WriteTo(packet, addr)
+}
+
+func (uc *socksUDPConn) ReadFrom(b []byte) (int, net.Addr, error) {
+	n, a, e := uc.PacketConn.ReadFrom(b)
+	if e != nil {
+		return 0, nil, e
+	}
+	addr, payload, err := socks5.DecodeUDPPacket(b)
+	if err != nil {
+		return 0, nil, err
+	}
+	// due to DecodeUDPPacket is mutable, record addr length
+	addrLength := len(addr)
+	copy(b, payload)
+	return n - addrLength - 3, a, nil
+}
+
+func (uc *socksUDPConn) Close() error {
+	uc.tcpConn.Close()
+	return uc.PacketConn.Close()
+}

adapters/outbound/urltest.go

@@ -5,7 +5,6 @@ import (
 	"encoding/json"
 	"errors"
 	"net"
-	"sync"
 	"sync/atomic"
 	"time"
 
@@ -34,16 +33,24 @@ func (u *URLTest) Now() string {
 	return u.fast.Name()
 }
 
-func (u *URLTest) Dial(metadata *C.Metadata) (net.Conn, error) {
-	a, err := u.fast.Dial(metadata)
-	if err != nil {
+func (u *URLTest) DialContext(ctx context.Context, metadata *C.Metadata) (c C.Conn, err error) {
+	for i := 0; i < 3; i++ {
+		c, err = u.fast.DialContext(ctx, metadata)
+		if err == nil {
+			c.AppendToChains(u)
+			return
+		}
 		u.fallback()
 	}
-	return a, err
+	return
 }
 
-func (u *URLTest) DialUDP(metadata *C.Metadata) (net.PacketConn, net.Addr, error) {
-	return u.fast.DialUDP(metadata)
+func (u *URLTest) DialUDP(metadata *C.Metadata) (C.PacketConn, net.Addr, error) {
+	pc, addr, err := u.fast.DialUDP(metadata)
+	if err == nil {
+		pc.AppendToChains(u)
+	}
+	return pc, addr, err
 }
 
 func (u *URLTest) SupportUDP() bool {
@@ -103,36 +110,26 @@ func (u *URLTest) speedTest() {
 	}
 	defer atomic.StoreInt32(&u.once, 0)
 
-	wg := sync.WaitGroup{}
-	wg.Add(len(u.proxies))
-	c := make(chan interface{})
-	fast := picker.SelectFast(context.Background(), c)
-	timer := time.NewTimer(u.interval)
-
+	ctx, cancel := context.WithTimeout(context.Background(), defaultURLTestTimeout)
+	defer cancel()
+	picker := picker.WithoutAutoCancel(ctx)
 	for _, p := range u.proxies {
-		go func(p C.Proxy) {
-			_, err := p.URLTest(u.rawURL)
-			if err == nil {
-				c <- p
+		proxy := p
+		picker.Go(func() (interface{}, error) {
+			_, err := proxy.URLTest(ctx, u.rawURL)
+			if err != nil {
+				return nil, err
 			}
-			wg.Done()
-		}(p)
+			return proxy, nil
+		})
 	}
 
-	go func() {
-		wg.Wait()
-		close(c)
-	}()
-
-	select {
-	case <-timer.C:
-		// Wait for fast to return or close.
-		<-fast
-	case p, open := <-fast:
-		if open {
-			u.fast = p.(C.Proxy)
-		}
+	fast := picker.WaitWithoutCancel()
+	if fast != nil {
+		u.fast = fast.(C.Proxy)
 	}
+
+	picker.Wait()
 }
 
 func NewURLTest(option URLTestOption, proxies []C.Proxy) (*URLTest, error) {

adapters/outbound/util.go

@@ -2,6 +2,7 @@ package adapters
 
 import (
 	"bytes"
+	"context"
 	"crypto/tls"
 	"fmt"
 	"net"
@@ -85,31 +86,84 @@ func serializesSocksAddr(metadata *C.Metadata) []byte {
 	return bytes.Join(buf, nil)
 }
 
-type fakeUDPConn struct {
-	net.Conn
-}
-
-func (fuc *fakeUDPConn) WriteTo(b []byte, addr net.Addr) (int, error) {
-	return fuc.Conn.Write(b)
-}
-
-func (fuc *fakeUDPConn) ReadFrom(b []byte) (int, net.Addr, error) {
-	n, err := fuc.Conn.Read(b)
-	return n, fuc.RemoteAddr(), err
-}
-
-func dialTimeout(network, address string, timeout time.Duration) (net.Conn, error) {
+func dialContext(ctx context.Context, network, address string) (net.Conn, error) {
 	host, port, err := net.SplitHostPort(address)
 	if err != nil {
 		return nil, err
 	}
 
-	ip, err := dns.ResolveIP(host)
-	if err != nil {
-		return nil, err
+	dialer := net.Dialer{}
+
+	returned := make(chan struct{})
+	defer close(returned)
+
+	type dialResult struct {
+		net.Conn
+		error
+		resolved bool
+		ipv6     bool
+		done     bool
+	}
+	results := make(chan dialResult)
+	var primary, fallback dialResult
+
+	startRacer := func(ctx context.Context, host string, ipv6 bool) {
+		result := dialResult{ipv6: ipv6, done: true}
+		defer func() {
+			select {
+			case results <- result:
+			case <-returned:
+				if result.Conn != nil {
+					result.Conn.Close()
+				}
+			}
+		}()
+
+		var ip net.IP
+		if ipv6 {
+			ip, result.error = dns.ResolveIPv6(host)
+		} else {
+			ip, result.error = dns.ResolveIPv4(host)
+		}
+		if result.error != nil {
+			return
+		}
+		result.resolved = true
+
+		if ipv6 {
+			result.Conn, result.error = dialer.DialContext(ctx, "tcp6", net.JoinHostPort(ip.String(), port))
+		} else {
+			result.Conn, result.error = dialer.DialContext(ctx, "tcp4", net.JoinHostPort(ip.String(), port))
+		}
 	}
 
-	return net.DialTimeout(network, net.JoinHostPort(ip.String(), port), timeout)
+	go startRacer(ctx, host, false)
+	go startRacer(ctx, host, true)
+
+	for {
+		select {
+		case res := <-results:
+			if res.error == nil {
+				return res.Conn, nil
+			}
+
+			if !res.ipv6 {
+				primary = res
+			} else {
+				fallback = res
+			}
+
+			if primary.done && fallback.done {
+				if primary.resolved {
+					return nil, primary.error
+				} else if fallback.resolved {
+					return nil, fallback.error
+				} else {
+					return nil, primary.error
+				}
+			}
+		}
+	}
 }
 
 func resolveUDPAddr(network, address string) (*net.UDPAddr, error) {

adapters/outbound/vmess.go

@@ -1,6 +1,7 @@
 package adapters
 
 import (
+	"context"
 	"fmt"
 	"net"
 	"strconv"
@@ -31,24 +32,29 @@ type VmessOption struct {
 	SkipCertVerify bool              `proxy:"skip-cert-verify,omitempty"`
 }
 
-func (v *Vmess) Dial(metadata *C.Metadata) (net.Conn, error) {
-	c, err := dialTimeout("tcp", v.server, tcpTimeout)
+func (v *Vmess) DialContext(ctx context.Context, metadata *C.Metadata) (C.Conn, error) {
+	c, err := dialContext(ctx, "tcp", v.server)
 	if err != nil {
 		return nil, fmt.Errorf("%s connect error", v.server)
 	}
 	tcpKeepAlive(c)
 	c, err = v.client.New(c, parseVmessAddr(metadata))
-	return c, err
+	return newConn(c, v), err
 }
 
-func (v *Vmess) DialUDP(metadata *C.Metadata) (net.PacketConn, net.Addr, error) {
-	c, err := dialTimeout("tcp", v.server, tcpTimeout)
+func (v *Vmess) DialUDP(metadata *C.Metadata) (C.PacketConn, net.Addr, error) {
+	ctx, cancel := context.WithTimeout(context.Background(), tcpTimeout)
+	defer cancel()
+	c, err := dialContext(ctx, "tcp", v.server)
 	if err != nil {
 		return nil, nil, fmt.Errorf("%s connect error", v.server)
 	}
 	tcpKeepAlive(c)
 	c, err = v.client.New(c, parseVmessAddr(metadata))
-	return &fakeUDPConn{Conn: c}, c.LocalAddr(), err
+	if err != nil {
+		return nil, nil, fmt.Errorf("new vmess client error: %v", err)
+	}
+	return newPacketConn(&vmessUDPConn{Conn: c}, v), c.RemoteAddr(), nil
 }
 
 func NewVmess(option VmessOption) (*Vmess, error) {
@@ -64,7 +70,7 @@ func NewVmess(option VmessOption) (*Vmess, error) {
 		WebSocketPath:    option.WSPath,
 		WebSocketHeaders: option.WSHeaders,
 		SkipCertVerify:   option.SkipCertVerify,
-		SessionCacahe:    getClientSessionCache(),
+		SessionCache:     getClientSessionCache(),
 	})
 	if err != nil {
 		return nil, err
@@ -74,7 +80,7 @@ func NewVmess(option VmessOption) (*Vmess, error) {
 		Base: &Base{
 			name: option.Name,
 			tp:   C.Vmess,
-			udp:  option.UDP,
+			udp:  true,
 		},
 		server: net.JoinHostPort(option.Server, strconv.Itoa(option.Port)),
 		client: client,
@@ -108,3 +114,16 @@ func parseVmessAddr(metadata *C.Metadata) *vmess.DstAddr {
 		Port:     uint(port),
 	}
 }
+
+type vmessUDPConn struct {
+	net.Conn
+}
+
+func (uc *vmessUDPConn) WriteTo(b []byte, addr net.Addr) (int, error) {
+	return uc.Conn.Write(b)
+}
+
+func (uc *vmessUDPConn) ReadFrom(b []byte) (int, net.Addr, error) {
+	n, err := uc.Conn.Read(b)
+	return n, uc.RemoteAddr(), err
+}

common/cache/cache_test.go

@@ -4,6 +4,8 @@ import (
 	"runtime"
 	"testing"
 	"time"
+
+	"github.com/stretchr/testify/assert"
 )
 
 func TestCache_Basic(t *testing.T) {
@@ -14,32 +16,30 @@ func TestCache_Basic(t *testing.T) {
 	c.Put("string", "a", ttl)
 
 	i := c.Get("int")
-	if i.(int) != 1 {
-		t.Error("should recv 1")
-	}
+	assert.Equal(t, i.(int), 1, "should recv 1")
 
 	s := c.Get("string")
-	if s.(string) != "a" {
-		t.Error("should recv 'a'")
-	}
+	assert.Equal(t, s.(string), "a", "should recv 'a'")
 }
 
 func TestCache_TTL(t *testing.T) {
 	interval := 200 * time.Millisecond
 	ttl := 20 * time.Millisecond
+	now := time.Now()
 	c := New(interval)
 	c.Put("int", 1, ttl)
+	c.Put("int2", 2, ttl)
 
 	i := c.Get("int")
-	if i.(int) != 1 {
-		t.Error("should recv 1")
-	}
+	_, expired := c.GetWithExpire("int2")
+	assert.Equal(t, i.(int), 1, "should recv 1")
+	assert.True(t, now.Before(expired))
 
 	time.Sleep(ttl * 2)
 	i = c.Get("int")
-	if i != nil {
-		t.Error("should recv nil")
-	}
+	j, _ := c.GetWithExpire("int2")
+	assert.Nil(t, i, "should recv nil")
+	assert.Nil(t, j, "should recv nil")
 }
 
 func TestCache_AutoCleanup(t *testing.T) {
@@ -50,9 +50,9 @@ func TestCache_AutoCleanup(t *testing.T) {
 
 	time.Sleep(ttl * 2)
 	i := c.Get("int")
-	if i != nil {
-		t.Error("should recv nil")
-	}
+	j, _ := c.GetWithExpire("int")
+	assert.Nil(t, i, "should recv nil")
+	assert.Nil(t, j, "should recv nil")
 }
 
 func TestCache_AutoGC(t *testing.T) {

common/cache/lrucache.go

@@ -0,0 +1,157 @@
+package cache
+
+// Modified by https://github.com/die-net/lrucache
+
+import (
+	"container/list"
+	"sync"
+	"time"
+)
+
+// Option is part of Functional Options Pattern
+type Option func(*LruCache)
+
+// WithUpdateAgeOnGet update expires when Get element
+func WithUpdateAgeOnGet() Option {
+	return func(l *LruCache) {
+		l.updateAgeOnGet = true
+	}
+}
+
+// WithAge defined element max age (second)
+func WithAge(maxAge int64) Option {
+	return func(l *LruCache) {
+		l.maxAge = maxAge
+	}
+}
+
+// WithSize defined max length of LruCache
+func WithSize(maxSize int) Option {
+	return func(l *LruCache) {
+		l.maxSize = maxSize
+	}
+}
+
+// LruCache is a thread-safe, in-memory lru-cache that evicts the
+// least recently used entries from memory when (if set) the entries are
+// older than maxAge (in seconds).  Use the New constructor to create one.
+type LruCache struct {
+	maxAge         int64
+	maxSize        int
+	mu             sync.Mutex
+	cache          map[interface{}]*list.Element
+	lru            *list.List // Front is least-recent
+	updateAgeOnGet bool
+}
+
+// NewLRUCache creates an LruCache
+func NewLRUCache(options ...Option) *LruCache {
+	lc := &LruCache{
+		lru:   list.New(),
+		cache: make(map[interface{}]*list.Element),
+	}
+
+	for _, option := range options {
+		option(lc)
+	}
+
+	return lc
+}
+
+// Get returns the interface{} representation of a cached response and a bool
+// set to true if the key was found.
+func (c *LruCache) Get(key interface{}) (interface{}, bool) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	le, ok := c.cache[key]
+	if !ok {
+		return nil, false
+	}
+
+	if c.maxAge > 0 && le.Value.(*entry).expires <= time.Now().Unix() {
+		c.deleteElement(le)
+		c.maybeDeleteOldest()
+
+		return nil, false
+	}
+
+	c.lru.MoveToBack(le)
+	entry := le.Value.(*entry)
+	if c.maxAge > 0 && c.updateAgeOnGet {
+		entry.expires = time.Now().Unix() + c.maxAge
+	}
+	value := entry.value
+
+	return value, true
+}
+
+// Exist returns if key exist in cache but not put item to the head of linked list
+func (c *LruCache) Exist(key interface{}) bool {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	_, ok := c.cache[key]
+	return ok
+}
+
+// Set stores the interface{} representation of a response for a given key.
+func (c *LruCache) Set(key interface{}, value interface{}) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	expires := int64(0)
+	if c.maxAge > 0 {
+		expires = time.Now().Unix() + c.maxAge
+	}
+
+	if le, ok := c.cache[key]; ok {
+		c.lru.MoveToBack(le)
+		e := le.Value.(*entry)
+		e.value = value
+		e.expires = expires
+	} else {
+		e := &entry{key: key, value: value, expires: expires}
+		c.cache[key] = c.lru.PushBack(e)
+
+		if c.maxSize > 0 {
+			if len := c.lru.Len(); len > c.maxSize {
+				c.deleteElement(c.lru.Front())
+			}
+		}
+	}
+
+	c.maybeDeleteOldest()
+}
+
+// Delete removes the value associated with a key.
+func (c *LruCache) Delete(key string) {
+	c.mu.Lock()
+
+	if le, ok := c.cache[key]; ok {
+		c.deleteElement(le)
+	}
+
+	c.mu.Unlock()
+}
+
+func (c *LruCache) maybeDeleteOldest() {
+	if c.maxAge > 0 {
+		now := time.Now().Unix()
+		for le := c.lru.Front(); le != nil && le.Value.(*entry).expires <= now; le = c.lru.Front() {
+			c.deleteElement(le)
+		}
+	}
+}
+
+func (c *LruCache) deleteElement(le *list.Element) {
+	c.lru.Remove(le)
+	e := le.Value.(*entry)
+	delete(c.cache, e.key)
+}
+
+type entry struct {
+	key     interface{}
+	value   interface{}
+	expires int64
+}

common/cache/lrucache_test.go

@@ -0,0 +1,117 @@
+package cache
+
+import (
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+)
+
+var entries = []struct {
+	key   string
+	value string
+}{
+	{"1", "one"},
+	{"2", "two"},
+	{"3", "three"},
+	{"4", "four"},
+	{"5", "five"},
+}
+
+func TestLRUCache(t *testing.T) {
+	c := NewLRUCache()
+
+	for _, e := range entries {
+		c.Set(e.key, e.value)
+	}
+
+	c.Delete("missing")
+	_, ok := c.Get("missing")
+	assert.False(t, ok)
+
+	for _, e := range entries {
+		value, ok := c.Get(e.key)
+		if assert.True(t, ok) {
+			assert.Equal(t, e.value, value.(string))
+		}
+	}
+
+	for _, e := range entries {
+		c.Delete(e.key)
+
+		_, ok := c.Get(e.key)
+		assert.False(t, ok)
+	}
+}
+
+func TestLRUMaxAge(t *testing.T) {
+	c := NewLRUCache(WithAge(86400))
+
+	now := time.Now().Unix()
+	expected := now + 86400
+
+	// Add one expired entry
+	c.Set("foo", "bar")
+	c.lru.Back().Value.(*entry).expires = now
+
+	// Reset
+	c.Set("foo", "bar")
+	e := c.lru.Back().Value.(*entry)
+	assert.True(t, e.expires >= now)
+	c.lru.Back().Value.(*entry).expires = now
+
+	// Set a few and verify expiration times
+	for _, s := range entries {
+		c.Set(s.key, s.value)
+		e := c.lru.Back().Value.(*entry)
+		assert.True(t, e.expires >= expected && e.expires <= expected+10)
+	}
+
+	// Make sure we can get them all
+	for _, s := range entries {
+		_, ok := c.Get(s.key)
+		assert.True(t, ok)
+	}
+
+	// Expire all entries
+	for _, s := range entries {
+		le, ok := c.cache[s.key]
+		if assert.True(t, ok) {
+			le.Value.(*entry).expires = now
+		}
+	}
+
+	// Get one expired entry, which should clear all expired entries
+	_, ok := c.Get("3")
+	assert.False(t, ok)
+	assert.Equal(t, c.lru.Len(), 0)
+}
+
+func TestLRUpdateOnGet(t *testing.T) {
+	c := NewLRUCache(WithAge(86400), WithUpdateAgeOnGet())
+
+	now := time.Now().Unix()
+	expires := now + 86400/2
+
+	// Add one expired entry
+	c.Set("foo", "bar")
+	c.lru.Back().Value.(*entry).expires = expires
+
+	_, ok := c.Get("foo")
+	assert.True(t, ok)
+	assert.True(t, c.lru.Back().Value.(*entry).expires > expires)
+}
+
+func TestMaxSize(t *testing.T) {
+	c := NewLRUCache(WithSize(2))
+	// Add one expired entry
+	c.Set("foo", "bar")
+	_, ok := c.Get("foo")
+	assert.True(t, ok)
+
+	c.Set("bar", "foo")
+	c.Set("baz", "foo")
+
+	_, ok = c.Get("foo")
+	assert.False(t, ok)
+}

common/picker/picker.go

@@ -1,22 +1,89 @@
 package picker
 
-import "context"
+import (
+	"context"
+	"sync"
+	"time"
+)
+
+// Picker provides synchronization, and Context cancelation
+// for groups of goroutines working on subtasks of a common task.
+// Inspired by errGroup
+type Picker struct {
+	ctx    context.Context
+	cancel func()
+
+	wg sync.WaitGroup
+
+	once   sync.Once
+	result interface{}
+
+	firstDone chan struct{}
+}
+
+func newPicker(ctx context.Context, cancel func()) *Picker {
+	return &Picker{
+		ctx:       ctx,
+		cancel:    cancel,
+		firstDone: make(chan struct{}, 1),
+	}
+}
+
+// WithContext returns a new Picker and an associated Context derived from ctx.
+// and cancel when first element return.
+func WithContext(ctx context.Context) (*Picker, context.Context) {
+	ctx, cancel := context.WithCancel(ctx)
+	return newPicker(ctx, cancel), ctx
+}
+
+// WithTimeout returns a new Picker and an associated Context derived from ctx with timeout.
+func WithTimeout(ctx context.Context, timeout time.Duration) (*Picker, context.Context) {
+	ctx, cancel := context.WithTimeout(ctx, timeout)
+	return newPicker(ctx, cancel), ctx
+}
+
+// WithoutAutoCancel returns a new Picker and an associated Context derived from ctx,
+// but it wouldn't cancel context when the first element return.
+func WithoutAutoCancel(ctx context.Context) *Picker {
+	return newPicker(ctx, nil)
+}
+
+// Wait blocks until all function calls from the Go method have returned,
+// then returns the first nil error result (if any) from them.
+func (p *Picker) Wait() interface{} {
+	p.wg.Wait()
+	if p.cancel != nil {
+		p.cancel()
+	}
+	return p.result
+}
+
+// WaitWithoutCancel blocks until the first result return, if timeout will return nil.
+func (p *Picker) WaitWithoutCancel() interface{} {
+	select {
+	case <-p.firstDone:
+		return p.result
+	case <-p.ctx.Done():
+		return p.result
+	}
+}
+
+// Go calls the given function in a new goroutine.
+// The first call to return a nil error cancels the group; its result will be returned by Wait.
+func (p *Picker) Go(f func() (interface{}, error)) {
+	p.wg.Add(1)
 
-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():
-		}
+		defer p.wg.Done()
 
-		close(out)
-		for range in {
+		if ret, err := f(); err == nil {
+			p.once.Do(func() {
+				p.result = ret
+				p.firstDone <- struct{}{}
+				if p.cancel != nil {
+					p.cancel()
+				}
+			})
 		}
 	}()
-
-	return out
 }

common/picker/picker_test.go

@@ -4,41 +4,63 @@ import (
 	"context"
 	"testing"
 	"time"
+
+	"github.com/stretchr/testify/assert"
 )
 
-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 sleepAndSend(ctx context.Context, delay int, input interface{}) func() (interface{}, error) {
+	return func() (interface{}, error) {
+		timer := time.NewTimer(time.Millisecond * time.Duration(delay))
+		select {
+		case <-timer.C:
+			return input, nil
+		case <-ctx.Done():
+			return nil, ctx.Err()
+		}
+	}
 }
 
 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)
+	picker, ctx := WithContext(context.Background())
+	picker.Go(sleepAndSend(ctx, 30, 2))
+	picker.Go(sleepAndSend(ctx, 20, 1))
 
-	number, exist := <-fast
-	if !exist || number != 1 {
-		t.Error("should recv 1", exist, number)
-	}
+	number := picker.Wait()
+	assert.NotNil(t, number)
+	assert.Equal(t, number.(int), 1)
 }
 
 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)
+	picker, ctx := WithTimeout(context.Background(), time.Millisecond*5)
+	picker.Go(sleepAndSend(ctx, 20, 1))
 
-	_, exist := <-fast
-	if exist {
-		t.Error("should recv false")
-	}
+	number := picker.Wait()
+	assert.Nil(t, number)
+}
+
+func TestPicker_WaitWithoutAutoCancel(t *testing.T) {
+	ctx, cancel := context.WithTimeout(context.Background(), time.Millisecond*60)
+	defer cancel()
+	picker := WithoutAutoCancel(ctx)
+
+	trigger := false
+	picker.Go(sleepAndSend(ctx, 10, 1))
+	picker.Go(func() (interface{}, error) {
+		timer := time.NewTimer(time.Millisecond * time.Duration(30))
+		select {
+		case <-timer.C:
+			trigger = true
+			return 2, nil
+		case <-ctx.Done():
+			return nil, ctx.Err()
+		}
+	})
+	elm := picker.WaitWithoutCancel()
+
+	assert.NotNil(t, elm)
+	assert.Equal(t, elm.(int), 1)
+
+	elm = picker.Wait()
+	assert.True(t, trigger)
+	assert.Equal(t, elm.(int), 1)
 }

common/queue/queue.go

@@ -34,16 +34,16 @@ func (q *Queue) Pop() interface{} {
 	return head
 }
 
-// First returns the head of items without deleting.
-func (q *Queue) First() interface{} {
+// Last returns the last of item.
+func (q *Queue) Last() interface{} {
 	if len(q.items) == 0 {
 		return nil
 	}
 
 	q.lock.RLock()
-	head := q.items[0]
+	last := q.items[len(q.items)-1]
 	q.lock.RUnlock()
-	return head
+	return last
 }
 
 // Copy get the copy of queue.

component/domain-trie/node.go

@@ -0,0 +1,26 @@
+package trie
+
+// Node is the trie's node
+type Node struct {
+	Data     interface{}
+	children map[string]*Node
+}
+
+func (n *Node) getChild(s string) *Node {
+	return n.children[s]
+}
+
+func (n *Node) hasChild(s string) bool {
+	return n.getChild(s) != nil
+}
+
+func (n *Node) addChild(s string, child *Node) {
+	n.children[s] = child
+}
+
+func newNode(data interface{}) *Node {
+	return &Node{
+		Data:     data,
+		children: map[string]*Node{},
+	}
+}

component/domain-trie/tire.go

@@ -0,0 +1,92 @@
+package trie
+
+import (
+	"errors"
+	"strings"
+)
+
+const (
+	wildcard   = "*"
+	domainStep = "."
+)
+
+var (
+	// ErrInvalidDomain means insert domain is invalid
+	ErrInvalidDomain = errors.New("invalid domain")
+)
+
+// Trie contains the main logic for adding and searching nodes for domain segments.
+// support wildcard domain (e.g *.google.com)
+type Trie struct {
+	root *Node
+}
+
+func isValidDomain(domain string) bool {
+	return domain != "" && domain[0] != '.' && domain[len(domain)-1] != '.'
+}
+
+// Insert adds a node to the trie.
+// Support
+// 1. www.example.com
+// 2. *.example.com
+// 3. subdomain.*.example.com
+func (t *Trie) Insert(domain string, data interface{}) error {
+	if !isValidDomain(domain) {
+		return ErrInvalidDomain
+	}
+
+	parts := strings.Split(domain, domainStep)
+	node := t.root
+	// reverse storage domain part to save space
+	for i := len(parts) - 1; i >= 0; i-- {
+		part := parts[i]
+		if !node.hasChild(part) {
+			node.addChild(part, newNode(nil))
+		}
+
+		node = node.getChild(part)
+	}
+
+	node.Data = data
+	return nil
+}
+
+// Search is the most important part of the Trie.
+// Priority as:
+// 1. static part
+// 2. wildcard domain
+func (t *Trie) Search(domain string) *Node {
+	if !isValidDomain(domain) {
+		return nil
+	}
+	parts := strings.Split(domain, domainStep)
+
+	n := t.root
+	for i := len(parts) - 1; i >= 0; i-- {
+		part := parts[i]
+
+		var child *Node
+		if !n.hasChild(part) {
+			if !n.hasChild(wildcard) {
+				return nil
+			}
+
+			child = n.getChild(wildcard)
+		} else {
+			child = n.getChild(part)
+		}
+
+		n = child
+	}
+
+	if n.Data == nil {
+		return nil
+	}
+
+	return n
+}
+
+// New returns a new, empty Trie.
+func New() *Trie {
+	return &Trie{root: newNode(nil)}
+}

component/domain-trie/trie_test.go

@@ -0,0 +1,87 @@
+package trie
+
+import (
+	"net"
+	"testing"
+)
+
+var localIP = net.IP{127, 0, 0, 1}
+
+func TestTrie_Basic(t *testing.T) {
+	tree := New()
+	domains := []string{
+		"example.com",
+		"google.com",
+	}
+
+	for _, domain := range domains {
+		tree.Insert(domain, localIP)
+	}
+
+	node := tree.Search("example.com")
+	if node == nil {
+		t.Error("should not recv nil")
+	}
+
+	if !node.Data.(net.IP).Equal(localIP) {
+		t.Error("should equal 127.0.0.1")
+	}
+
+	if tree.Insert("", localIP) == nil {
+		t.Error("should return error")
+	}
+}
+
+func TestTrie_Wildcard(t *testing.T) {
+	tree := New()
+	domains := []string{
+		"*.example.com",
+		"sub.*.example.com",
+		"*.dev",
+	}
+
+	for _, domain := range domains {
+		tree.Insert(domain, localIP)
+	}
+
+	if tree.Search("sub.example.com") == nil {
+		t.Error("should not recv nil")
+	}
+
+	if tree.Search("sub.foo.example.com") == nil {
+		t.Error("should not recv nil")
+	}
+
+	if tree.Search("foo.sub.example.com") != nil {
+		t.Error("should recv nil")
+	}
+
+	if tree.Search("foo.example.dev") != nil {
+		t.Error("should recv nil")
+	}
+
+	if tree.Search("example.com") != nil {
+		t.Error("should recv nil")
+	}
+}
+
+func TestTrie_Boundary(t *testing.T) {
+	tree := New()
+	tree.Insert("*.dev", localIP)
+
+	if err := tree.Insert(".", localIP); err == nil {
+		t.Error("should recv err")
+	}
+
+	if err := tree.Insert(".com", localIP); err == nil {
+		t.Error("should recv err")
+	}
+
+	if tree.Search("dev") != nil {
+		t.Error("should recv nil")
+	}
+
+	if tree.Search(".dev") != nil {
+		t.Error("should recv nil")
+	}
+}

component/fakeip/pool.go

@@ -4,22 +4,82 @@ import (
 	"errors"
 	"net"
 	"sync"
+
+	"github.com/Dreamacro/clash/common/cache"
 )
 
 // Pool is a implementation about fake ip generator without storage
 type Pool struct {
-	max    uint32
-	min    uint32
-	offset uint32
-	mux    *sync.Mutex
+	max     uint32
+	min     uint32
+	gateway uint32
+	offset  uint32
+	mux     *sync.Mutex
+	cache   *cache.LruCache
 }
 
-// Get return a new fake ip
-func (p *Pool) Get() net.IP {
+// Lookup return a fake ip with host
+func (p *Pool) Lookup(host string) net.IP {
 	p.mux.Lock()
 	defer p.mux.Unlock()
-	ip := uintToIP(p.min + p.offset)
-	p.offset = (p.offset + 1) % (p.max - p.min)
+	if elm, exist := p.cache.Get(host); exist {
+		ip := elm.(net.IP)
+
+		// ensure ip --> host on head of linked list
+		n := ipToUint(ip.To4())
+		offset := n - p.min + 1
+		p.cache.Get(offset)
+		return ip
+	}
+
+	ip := p.get(host)
+	p.cache.Set(host, ip)
+	return ip
+}
+
+// LookBack return host with the fake ip
+func (p *Pool) LookBack(ip net.IP) (string, bool) {
+	p.mux.Lock()
+	defer p.mux.Unlock()
+
+	if ip = ip.To4(); ip == nil {
+		return "", false
+	}
+
+	n := ipToUint(ip.To4())
+	offset := n - p.min + 1
+
+	if elm, exist := p.cache.Get(offset); exist {
+		host := elm.(string)
+
+		// ensure host --> ip on head of linked list
+		p.cache.Get(host)
+		return host, true
+	}
+
+	return "", false
+}
+
+// Gateway return gateway ip
+func (p *Pool) Gateway() net.IP {
+	return uintToIP(p.gateway)
+}
+
+func (p *Pool) get(host string) net.IP {
+	current := p.offset
+	for {
+		p.offset = (p.offset + 1) % (p.max - p.min)
+		// Avoid infinite loops
+		if p.offset == current {
+			break
+		}
+
+		if !p.cache.Exist(p.offset) {
+			break
+		}
+	}
+	ip := uintToIP(p.min + p.offset - 1)
+	p.cache.Set(p.offset, host)
 	return ip
 }
 
@@ -36,8 +96,8 @@ func uintToIP(v uint32) net.IP {
 }
 
 // New return Pool instance
-func New(ipnet *net.IPNet) (*Pool, error) {
-	min := ipToUint(ipnet.IP) + 1
+func New(ipnet *net.IPNet, size int) (*Pool, error) {
+	min := ipToUint(ipnet.IP) + 2
 
 	ones, bits := ipnet.Mask.Size()
 	total := 1<<uint(bits-ones) - 2
@@ -46,10 +106,12 @@ func New(ipnet *net.IPNet) (*Pool, error) {
 		return nil, errors.New("ipnet don't have valid ip")
 	}
 
-	max := min + uint32(total)
+	max := min + uint32(total) - 1
 	return &Pool{
-		min: min,
-		max: max,
-		mux: &sync.Mutex{},
+		min:     min,
+		max:     max,
+		gateway: min - 1,
+		mux:     &sync.Mutex{},
+		cache:   cache.NewLRUCache(cache.WithSize(size * 2)),
 	}, nil
 }

component/fakeip/pool_test.go

@@ -3,42 +3,76 @@ package fakeip
 import (
 	"net"
 	"testing"
+
+	"github.com/stretchr/testify/assert"
 )
 
 func TestPool_Basic(t *testing.T) {
-	_, ipnet, _ := net.ParseCIDR("192.168.0.1/30")
-	pool, _ := New(ipnet)
+	_, ipnet, _ := net.ParseCIDR("192.168.0.1/29")
+	pool, _ := New(ipnet, 10)
 
-	first := pool.Get()
-	last := pool.Get()
+	first := pool.Lookup("foo.com")
+	last := pool.Lookup("bar.com")
+	bar, exist := pool.LookBack(last)
 
-	if !first.Equal(net.IP{192, 168, 0, 1}) {
-		t.Error("should get right first ip, instead of", first.String())
-	}
-
-	if !last.Equal(net.IP{192, 168, 0, 2}) {
-		t.Error("should get right last ip, instead of", first.String())
-	}
+	assert.True(t, first.Equal(net.IP{192, 168, 0, 2}))
+	assert.True(t, last.Equal(net.IP{192, 168, 0, 3}))
+	assert.True(t, exist)
+	assert.Equal(t, bar, "bar.com")
 }
 
 func TestPool_Cycle(t *testing.T) {
 	_, ipnet, _ := net.ParseCIDR("192.168.0.1/30")
-	pool, _ := New(ipnet)
+	pool, _ := New(ipnet, 10)
 
-	first := pool.Get()
-	pool.Get()
-	same := pool.Get()
+	first := pool.Lookup("foo.com")
+	same := pool.Lookup("baz.com")
 
-	if !first.Equal(same) {
-		t.Error("should return same ip", first.String())
-	}
+	assert.True(t, first.Equal(same))
+}
+
+func TestPool_MaxCacheSize(t *testing.T) {
+	_, ipnet, _ := net.ParseCIDR("192.168.0.1/24")
+	pool, _ := New(ipnet, 2)
+
+	first := pool.Lookup("foo.com")
+	pool.Lookup("bar.com")
+	pool.Lookup("baz.com")
+	next := pool.Lookup("foo.com")
+
+	assert.False(t, first.Equal(next))
+}
+
+func TestPool_DoubleMapping(t *testing.T) {
+	_, ipnet, _ := net.ParseCIDR("192.168.0.1/24")
+	pool, _ := New(ipnet, 2)
+
+	// fill cache
+	fooIP := pool.Lookup("foo.com")
+	bazIP := pool.Lookup("baz.com")
+
+	// make foo.com hot
+	pool.Lookup("foo.com")
+
+	// should drop baz.com
+	barIP := pool.Lookup("bar.com")
+
+	_, fooExist := pool.LookBack(fooIP)
+	_, bazExist := pool.LookBack(bazIP)
+	_, barExist := pool.LookBack(barIP)
+
+	newBazIP := pool.Lookup("baz.com")
+
+	assert.True(t, fooExist)
+	assert.False(t, bazExist)
+	assert.True(t, barExist)
+
+	assert.False(t, bazIP.Equal(newBazIP))
 }
 
 func TestPool_Error(t *testing.T) {
 	_, ipnet, _ := net.ParseCIDR("192.168.0.1/31")
-	_, err := New(ipnet)
+	_, err := New(ipnet, 10)
 
-	if err == nil {
-		t.Error("should return err")
-	}
+	assert.Error(t, err)
 }

component/nat/table.go

@@ -0,0 +1,46 @@
+package nat
+
+import (
+	"net"
+	"sync"
+)
+
+type Table struct {
+	mapping sync.Map
+}
+
+type element struct {
+	RemoteAddr net.Addr
+	RemoteConn net.PacketConn
+}
+
+func (t *Table) Set(key string, pc net.PacketConn, addr net.Addr) {
+	// set conn read timeout
+	t.mapping.Store(key, &element{
+		RemoteConn: pc,
+		RemoteAddr: addr,
+	})
+}
+
+func (t *Table) Get(key string) (net.PacketConn, net.Addr) {
+	item, exist := t.mapping.Load(key)
+	if !exist {
+		return nil, nil
+	}
+	elm := item.(*element)
+	return elm.RemoteConn, elm.RemoteAddr
+}
+
+func (t *Table) GetOrCreateLock(key string) (*sync.WaitGroup, bool) {
+	item, loaded := t.mapping.LoadOrStore(key, &sync.WaitGroup{})
+	return item.(*sync.WaitGroup), loaded
+}
+
+func (t *Table) Delete(key string) {
+	t.mapping.Delete(key)
+}
+
+// New return *Cache
+func New() *Table {
+	return &Table{}
+}

component/snell/cipher.go

@@ -0,0 +1,21 @@
+package snell
+
+import (
+	"crypto/cipher"
+
+	"golang.org/x/crypto/argon2"
+)
+
+type snellCipher struct {
+	psk      []byte
+	makeAEAD func(key []byte) (cipher.AEAD, error)
+}
+
+func (sc *snellCipher) KeySize() int  { return 32 }
+func (sc *snellCipher) SaltSize() int { return 16 }
+func (sc *snellCipher) Encrypter(salt []byte) (cipher.AEAD, error) {
+	return sc.makeAEAD(argon2.IDKey(sc.psk, salt, 3, 8, 1, uint32(sc.KeySize())))
+}
+func (sc *snellCipher) Decrypter(salt []byte) (cipher.AEAD, error) {
+	return sc.makeAEAD(argon2.IDKey(sc.psk, salt, 3, 8, 1, uint32(sc.KeySize())))
+}

component/snell/snell.go

@@ -0,0 +1,91 @@
+package snell
+
+import (
+	"bytes"
+	"encoding/binary"
+	"errors"
+	"io"
+	"net"
+	"sync"
+
+	"github.com/Dreamacro/go-shadowsocks2/shadowaead"
+	"golang.org/x/crypto/chacha20poly1305"
+)
+
+const (
+	CommandPing    byte = 0
+	CommandConnect byte = 1
+
+	CommandTunnel byte = 0
+	CommandError  byte = 2
+
+	Version byte = 1
+)
+
+var (
+	bufferPool = sync.Pool{New: func() interface{} { return &bytes.Buffer{} }}
+)
+
+type Snell struct {
+	net.Conn
+	buffer [1]byte
+	reply  bool
+}
+
+func (s *Snell) Read(b []byte) (int, error) {
+	if s.reply {
+		return s.Conn.Read(b)
+	}
+
+	s.reply = true
+	if _, err := io.ReadFull(s.Conn, s.buffer[:]); err != nil {
+		return 0, err
+	}
+
+	if s.buffer[0] == CommandTunnel {
+		return s.Conn.Read(b)
+	} else if s.buffer[0] != CommandError {
+		return 0, errors.New("Command not support")
+	}
+
+	// CommandError
+	if _, err := io.ReadFull(s.Conn, s.buffer[:]); err != nil {
+		return 0, err
+	}
+
+	length := int(s.buffer[0])
+	msg := make([]byte, length)
+
+	if _, err := io.ReadFull(s.Conn, msg); err != nil {
+		return 0, err
+	}
+
+	return 0, errors.New(string(msg))
+}
+
+func WriteHeader(conn net.Conn, host string, port uint) error {
+	buf := bufferPool.Get().(*bytes.Buffer)
+	buf.Reset()
+	defer bufferPool.Put(buf)
+	buf.WriteByte(Version)
+	buf.WriteByte(CommandConnect)
+
+	// clientID length & id
+	buf.WriteByte(0)
+
+	// host & port
+	buf.WriteByte(uint8(len(host)))
+	buf.WriteString(host)
+	binary.Write(buf, binary.BigEndian, uint16(port))
+
+	if _, err := conn.Write(buf.Bytes()); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func StreamConn(conn net.Conn, psk []byte) net.Conn {
+	cipher := &snellCipher{psk, chacha20poly1305.New}
+	return &Snell{Conn: shadowaead.NewConn(conn, cipher)}
+}

component/socks5/socks5.go

@@ -41,7 +41,26 @@ const MaxAddrLen = 1 + 1 + 255 + 2
 const MaxAuthLen = 255
 
 // Addr represents a SOCKS address as defined in RFC 1928 section 5.
-type Addr = []byte
+type Addr []byte
+
+func (a Addr) String() string {
+	var host, port string
+
+	switch a[0] {
+	case AtypDomainName:
+		hostLen := uint16(a[1])
+		host = string(a[2 : 2+hostLen])
+		port = strconv.Itoa((int(a[2+hostLen]) << 8) | int(a[2+hostLen+1]))
+	case AtypIPv4:
+		host = net.IP(a[1 : 1+net.IPv4len]).String()
+		port = strconv.Itoa((int(a[1+net.IPv4len]) << 8) | int(a[1+net.IPv4len+1]))
+	case AtypIPv6:
+		host = net.IP(a[1 : 1+net.IPv6len]).String()
+		port = strconv.Itoa((int(a[1+net.IPv6len]) << 8) | int(a[1+net.IPv6len+1]))
+	}
+
+	return net.JoinHostPort(host, port)
+}
 
 // SOCKS errors as defined in RFC 1928 section 6.
 const (
@@ -138,23 +157,33 @@ func ServerHandshake(rw net.Conn, authenticator auth.Authenticator) (addr Addr,
 		return
 	}
 
-	if buf[1] != CmdConnect && buf[1] != CmdUDPAssociate {
-		err = ErrCommandNotSupported
-		return
-	}
-
 	command = buf[1]
 	addr, err = readAddr(rw, buf)
 	if err != nil {
 		return
 	}
-	// write VER REP RSV ATYP BND.ADDR BND.PORT
-	_, err = rw.Write([]byte{5, 0, 0, 1, 0, 0, 0, 0, 0, 0})
+
+	switch command {
+	case CmdConnect, CmdUDPAssociate:
+		// Acquire server listened address info
+		localAddr := ParseAddr(rw.LocalAddr().String())
+		if localAddr == nil {
+			err = ErrAddressNotSupported
+		} else {
+			// write VER REP RSV ATYP BND.ADDR BND.PORT
+			_, err = rw.Write(bytes.Join([][]byte{{5, 0, 0}, localAddr}, []byte{}))
+		}
+	case CmdBind:
+		fallthrough
+	default:
+		err = ErrCommandNotSupported
+	}
+
 	return
 }
 
 // ClientHandshake fast-tracks SOCKS initialization to get target address to connect on client side.
-func ClientHandshake(rw io.ReadWriter, addr Addr, cammand Command, user *User) error {
+func ClientHandshake(rw io.ReadWriter, addr Addr, command Command, user *User) (Addr, error) {
 	buf := make([]byte, MaxAddrLen)
 	var err error
 
@@ -165,16 +194,16 @@ func ClientHandshake(rw io.ReadWriter, addr Addr, cammand Command, user *User) e
 		_, err = rw.Write([]byte{5, 1, 0})
 	}
 	if err != nil {
-		return err
+		return nil, err
 	}
 
 	// VER, METHOD
 	if _, err := io.ReadFull(rw, buf[:2]); err != nil {
-		return err
+		return nil, err
 	}
 
 	if buf[0] != 5 {
-		return errors.New("SOCKS version error")
+		return nil, errors.New("SOCKS version error")
 	}
 
 	if buf[1] == 2 {
@@ -187,30 +216,31 @@ func ClientHandshake(rw io.ReadWriter, addr Addr, cammand Command, user *User) e
 		authMsg.WriteString(user.Password)
 
 		if _, err := rw.Write(authMsg.Bytes()); err != nil {
-			return err
+			return nil, err
 		}
 
 		if _, err := io.ReadFull(rw, buf[:2]); err != nil {
-			return err
+			return nil, err
 		}
 
 		if buf[1] != 0 {
-			return errors.New("rejected username/password")
+			return nil, errors.New("rejected username/password")
 		}
 	} else if buf[1] != 0 {
-		return errors.New("SOCKS need auth")
+		return nil, errors.New("SOCKS need auth")
 	}
 
 	// VER, CMD, RSV, ADDR
-	if _, err := rw.Write(bytes.Join([][]byte{{5, cammand, 0}, addr}, []byte(""))); err != nil {
-		return err
+	if _, err := rw.Write(bytes.Join([][]byte{{5, command, 0}, addr}, []byte{})); err != nil {
+		return nil, err
 	}
 
-	if _, err := io.ReadFull(rw, buf[:10]); err != nil {
-		return err
+	// VER, REP, RSV
+	if _, err := io.ReadFull(rw, buf[:3]); err != nil {
+		return nil, err
 	}
 
-	return nil
+	return readAddr(rw, buf)
 }
 
 func readAddr(r io.Reader, b []byte) (Addr, error) {
@@ -307,3 +337,39 @@ func ParseAddr(s string) Addr {
 
 	return addr
 }
+
+// DecodeUDPPacket split `packet` to addr payload, and this function is mutable with `packet`
+func DecodeUDPPacket(packet []byte) (addr Addr, payload []byte, err error) {
+	if len(packet) < 5 {
+		err = errors.New("insufficient length of packet")
+		return
+	}
+
+	// packet[0] and packet[1] are reserved
+	if !bytes.Equal(packet[:2], []byte{0, 0}) {
+		err = errors.New("reserved fields should be zero")
+		return
+	}
+
+	if packet[2] != 0 /* fragments */ {
+		err = errors.New("discarding fragmented payload")
+		return
+	}
+
+	addr = SplitAddr(packet[3:])
+	if addr == nil {
+		err = errors.New("failed to read UDP header")
+	}
+
+	payload = packet[3+len(addr):]
+	return
+}
+
+func EncodeUDPPacket(addr Addr, payload []byte) (packet []byte, err error) {
+	if addr == nil {
+		err = errors.New("address is invalid")
+		return
+	}
+	packet = bytes.Join([][]byte{{0, 0, 0}, addr, payload}, []byte{})
+	return
+}

component/v2ray-plugin/websocket.go

@@ -3,25 +3,32 @@ package obfs
 import (
 	"crypto/tls"
 	"net"
+	"net/http"
 
 	"github.com/Dreamacro/clash/component/vmess"
 )
 
-// WebsocketOption is options of websocket obfs
-type WebsocketOption struct {
+// Option is options of websocket obfs
+type Option struct {
 	Host      string
 	Path      string
 	Headers   map[string]string
 	TLSConfig *tls.Config
+	Mux       bool
 }
 
-// NewWebsocketObfs return a HTTPObfs
-func NewWebsocketObfs(conn net.Conn, option *WebsocketOption) (net.Conn, error) {
+// NewV2rayObfs return a HTTPObfs
+func NewV2rayObfs(conn net.Conn, option *Option) (net.Conn, error) {
+	header := http.Header{}
+	for k, v := range option.Headers {
+		header.Add(k, v)
+	}
+
 	config := &vmess.WebsocketConfig{
 		Host:      option.Host,
 		Path:      option.Path,
 		TLS:       option.TLSConfig != nil,
-		Headers:   option.Headers,
+		Headers:   header,
 		TLSConfig: option.TLSConfig,
 	}
 
@@ -30,10 +37,13 @@ func NewWebsocketObfs(conn net.Conn, option *WebsocketOption) (net.Conn, error)
 	if err != nil {
 		return nil, err
 	}
-	conn = NewMux(conn, MuxOption{
-		ID:   [2]byte{0, 0},
-		Host: "127.0.0.1",
-		Port: 0,
-	})
+
+	if option.Mux {
+		conn = NewMux(conn, MuxOption{
+			ID:   [2]byte{0, 0},
+			Host: "127.0.0.1",
+			Port: 0,
+		})
+	}
 	return conn, nil
 }

component/vmess/vmess.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"math/rand"
 	"net"
+	"net/http"
 	"runtime"
 	"sync"
 
@@ -86,7 +87,7 @@ type Config struct {
 	WebSocketPath    string
 	WebSocketHeaders map[string]string
 	SkipCertVerify   bool
-	SessionCacahe    tls.ClientSessionCache
+	SessionCache     tls.ClientSessionCache
 }
 
 // New return a Conn with net.Conn and DstAddr
@@ -132,6 +133,11 @@ func NewClient(config Config) (*Client, error) {
 		return nil, fmt.Errorf("Unknown network type: %s", config.NetWork)
 	}
 
+	header := http.Header{}
+	for k, v := range config.WebSocketHeaders {
+		header.Add(k, v)
+	}
+
 	host := net.JoinHostPort(config.HostName, config.Port)
 
 	var tlsConfig *tls.Config
@@ -139,11 +145,14 @@ func NewClient(config Config) (*Client, error) {
 		tlsConfig = &tls.Config{
 			ServerName:         config.HostName,
 			InsecureSkipVerify: config.SkipCertVerify,
-			ClientSessionCache: config.SessionCacahe,
+			ClientSessionCache: config.SessionCache,
 		}
 		if tlsConfig.ClientSessionCache == nil {
 			tlsConfig.ClientSessionCache = getClientSessionCache()
 		}
+		if host := header.Get("Host"); host != "" {
+			tlsConfig.ServerName = host
+		}
 	}
 
 	var wsConfig *WebsocketConfig
@@ -151,7 +160,7 @@ func NewClient(config Config) (*Client, error) {
 		wsConfig = &WebsocketConfig{
 			Host:      host,
 			Path:      config.WebSocketPath,
-			Headers:   config.WebSocketHeaders,
+			Headers:   header,
 			TLS:       config.TLS,
 			TLSConfig: tlsConfig,
 		}

component/vmess/websocket.go

@@ -22,7 +22,7 @@ type websocketConn struct {
 type WebsocketConfig struct {
 	Host      string
 	Path      string
-	Headers   map[string]string
+	Headers   http.Header
 	TLS       bool
 	TLSConfig *tls.Config
 }
@@ -131,14 +131,14 @@ func NewWebsocketConn(conn net.Conn, c *WebsocketConfig) (net.Conn, error) {
 
 	headers := http.Header{}
 	if c.Headers != nil {
-		for k, v := range c.Headers {
-			headers.Set(k, v)
+		for k := range c.Headers {
+			headers.Add(k, c.Headers.Get(k))
 		}
 	}
 
 	wsConn, resp, err := dialer.Dial(uri.String(), headers)
 	if err != nil {
-		var reason string
+		reason := err.Error()
 		if resp != nil {
 			reason = resp.Status
 		}

config/config.go

@@ -12,6 +12,7 @@ import (
 	adapters "github.com/Dreamacro/clash/adapters/outbound"
 	"github.com/Dreamacro/clash/common/structure"
 	"github.com/Dreamacro/clash/component/auth"
+	trie "github.com/Dreamacro/clash/component/domain-trie"
 	"github.com/Dreamacro/clash/component/fakeip"
 	C "github.com/Dreamacro/clash/constant"
 	"github.com/Dreamacro/clash/dns"
@@ -29,6 +30,7 @@ type General struct {
 	RedirPort          int          `json:"redir-port"`
 	Authentication     []string     `json:"authentication"`
 	AllowLan           bool         `json:"allow-lan"`
+	BindAddress        string       `json:"bind-address"`
 	Mode               T.Mode       `json:"mode"`
 	LogLevel           log.LogLevel `json:"log-level"`
 	ExternalController string       `json:"-"`
@@ -38,13 +40,20 @@ type General struct {
 
 // DNS config
 type DNS struct {
-	Enable       bool             `yaml:"enable"`
-	IPv6         bool             `yaml:"ipv6"`
-	NameServer   []dns.NameServer `yaml:"nameserver"`
-	Fallback     []dns.NameServer `yaml:"fallback"`
-	Listen       string           `yaml:"listen"`
-	EnhancedMode dns.EnhancedMode `yaml:"enhanced-mode"`
-	FakeIPRange  *fakeip.Pool
+	Enable         bool             `yaml:"enable"`
+	IPv6           bool             `yaml:"ipv6"`
+	NameServer     []dns.NameServer `yaml:"nameserver"`
+	Fallback       []dns.NameServer `yaml:"fallback"`
+	FallbackFilter FallbackFilter   `yaml:"fallback-filter"`
+	Listen         string           `yaml:"listen"`
+	EnhancedMode   dns.EnhancedMode `yaml:"enhanced-mode"`
+	FakeIPRange    *fakeip.Pool
+}
+
+// FallbackFilter config
+type FallbackFilter struct {
+	GeoIP  bool         `yaml:"geoip"`
+	IPCIDR []*net.IPNet `yaml:"ipcidr"`
 }
 
 // Experimental config
@@ -57,19 +66,26 @@ type Config struct {
 	General      *General
 	DNS          *DNS
 	Experimental *Experimental
+	Hosts        *trie.Trie
 	Rules        []C.Rule
 	Users        []auth.AuthUser
 	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"`
-	FakeIPRange  string           `yaml:"fake-ip-range"`
+	Enable         bool              `yaml:"enable"`
+	IPv6           bool              `yaml:"ipv6"`
+	NameServer     []string          `yaml:"nameserver"`
+	Fallback       []string          `yaml:"fallback"`
+	FallbackFilter rawFallbackFilter `yaml:"fallback-filter"`
+	Listen         string            `yaml:"listen"`
+	EnhancedMode   dns.EnhancedMode  `yaml:"enhanced-mode"`
+	FakeIPRange    string            `yaml:"fake-ip-range"`
+}
+
+type rawFallbackFilter struct {
+	GeoIP  bool     `yaml:"geoip"`
+	IPCIDR []string `yaml:"ipcidr"`
 }
 
 type rawConfig struct {
@@ -78,12 +94,14 @@ type rawConfig struct {
 	RedirPort          int          `yaml:"redir-port"`
 	Authentication     []string     `yaml:"authentication"`
 	AllowLan           bool         `yaml:"allow-lan"`
+	BindAddress        string       `yaml:"bind-address"`
 	Mode               T.Mode       `yaml:"mode"`
 	LogLevel           log.LogLevel `yaml:"log-level"`
 	ExternalController string       `yaml:"external-controller"`
 	ExternalUI         string       `yaml:"external-ui"`
 	Secret             string       `yaml:"secret"`
 
+	Hosts        map[string]string        `yaml:"hosts"`
 	DNS          rawDNS                   `yaml:"dns"`
 	Experimental Experimental             `yaml:"experimental"`
 	Proxy        []map[string]interface{} `yaml:"Proxy"`
@@ -103,7 +121,11 @@ func readRawConfig(path string) ([]byte, error) {
 	}
 
 	path = path[:len(path)-5] + ".yml"
-	return ioutil.ReadFile(path)
+	if _, err = os.Stat(path); err == nil {
+		return ioutil.ReadFile(path)
+	}
+
+	return data, nil
 }
 
 func readConfig(path string) (*rawConfig, error) {
@@ -122,9 +144,11 @@ func readConfig(path string) (*rawConfig, error) {
 	// config with some default value
 	rawConfig := &rawConfig{
 		AllowLan:       false,
+		BindAddress:    "*",
 		Mode:           T.Rule,
 		Authentication: []string{},
 		LogLevel:       log.INFO,
+		Hosts:          map[string]string{},
 		Rule:           []string{},
 		Proxy:          []map[string]interface{}{},
 		ProxyGroup:     []map[string]interface{}{},
@@ -134,6 +158,10 @@ func readConfig(path string) (*rawConfig, error) {
 		DNS: rawDNS{
 			Enable:      false,
 			FakeIPRange: "198.18.0.1/16",
+			FallbackFilter: rawFallbackFilter{
+				GeoIP:  true,
+				IPCIDR: []string{},
+			},
 		},
 	}
 	err = yaml.Unmarshal([]byte(data), &rawConfig)
@@ -174,6 +202,12 @@ func Parse(path string) (*Config, error) {
 	}
 	config.DNS = dnsCfg
 
+	hosts, err := parseHosts(rawCfg)
+	if err != nil {
+		return nil, err
+	}
+	config.Hosts = hosts
+
 	config.Users = parseAuthentication(rawCfg.Authentication)
 
 	return config, nil
@@ -184,6 +218,7 @@ func parseGeneral(cfg *rawConfig) (*General, error) {
 	socksPort := cfg.SocksPort
 	redirPort := cfg.RedirPort
 	allowLan := cfg.AllowLan
+	bindAddress := cfg.BindAddress
 	externalController := cfg.ExternalController
 	externalUI := cfg.ExternalUI
 	secret := cfg.Secret
@@ -205,6 +240,7 @@ func parseGeneral(cfg *rawConfig) (*General, error) {
 		SocksPort:          socksPort,
 		RedirPort:          redirPort,
 		AllowLan:           allowLan,
+		BindAddress:        bindAddress,
 		Mode:               mode,
 		LogLevel:           logLevel,
 		ExternalController: externalController,
@@ -264,6 +300,13 @@ func parseProxies(cfg *rawConfig) (map[string]C.Proxy, error) {
 				break
 			}
 			proxy, err = adapters.NewVmess(*vmessOption)
+		case "snell":
+			snellOption := &adapters.SnellOption{}
+			err = decoder.Decode(mapping, snellOption)
+			if err != nil {
+				break
+			}
+			proxy, err = adapters.NewSnell(*snellOption)
 		default:
 			return nil, fmt.Errorf("Unsupport proxy type: %s", proxyType)
 		}
@@ -279,12 +322,26 @@ func parseProxies(cfg *rawConfig) (map[string]C.Proxy, error) {
 		proxyList = append(proxyList, proxy.Name())
 	}
 
-	// parse proxy group
+	// keep the origional order of ProxyGroups in config file
 	for idx, mapping := range groupsConfig {
-		groupType, existType := mapping["type"].(string)
 		groupName, existName := mapping["name"].(string)
-		if !existType && existName {
-			return nil, fmt.Errorf("ProxyGroup %d: missing type or name", idx)
+		if !existName {
+			return nil, fmt.Errorf("ProxyGroup %d: missing name", idx)
+		}
+		proxyList = append(proxyList, groupName)
+	}
+
+	// check if any loop exists and sort the ProxyGroups
+	if err := proxyGroupsDagSort(groupsConfig, decoder); err != nil {
+		return nil, err
+	}
+
+	// parse proxy group
+	for _, mapping := range groupsConfig {
+		groupType, existType := mapping["type"].(string)
+		groupName, _ := mapping["name"].(string)
+		if !existType {
+			return nil, fmt.Errorf("ProxyGroup %s: missing type", groupName)
 		}
 
 		if _, exist := proxies[groupName]; exist {
@@ -348,7 +405,6 @@ func parseProxies(cfg *rawConfig) (map[string]C.Proxy, error) {
 			return nil, fmt.Errorf("Proxy %s: %s", groupName, err.Error())
 		}
 		proxies[groupName] = adapters.NewProxy(group)
-		proxyList = append(proxyList, groupName)
 	}
 
 	ps := []C.Proxy{}
@@ -434,6 +490,21 @@ func parseRules(cfg *rawConfig, proxies map[string]C.Proxy) ([]C.Rule, error) {
 	return rules, nil
 }
 
+func parseHosts(cfg *rawConfig) (*trie.Trie, error) {
+	tree := trie.New()
+	if len(cfg.Hosts) != 0 {
+		for domain, ipStr := range cfg.Hosts {
+			ip := net.ParseIP(ipStr)
+			if ip == nil {
+				return nil, fmt.Errorf("%s is not a valid IP", ipStr)
+			}
+			tree.Insert(domain, ip)
+		}
+	}
+
+	return tree, nil
+}
+
 func hostWithDefaultPort(host string, defPort string) (string, error) {
 	if !strings.Contains(host, ":") {
 		host += ":"
@@ -498,6 +569,20 @@ func parseNameServer(servers []string) ([]dns.NameServer, error) {
 	return nameservers, nil
 }
 
+func parseFallbackIPCIDR(ips []string) ([]*net.IPNet, error) {
+	ipNets := []*net.IPNet{}
+
+	for idx, ip := range ips {
+		_, ipnet, err := net.ParseCIDR(ip)
+		if err != nil {
+			return nil, fmt.Errorf("DNS FallbackIP[%d] format error: %s", idx, err.Error())
+		}
+		ipNets = append(ipNets, ipnet)
+	}
+
+	return ipNets, 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")
@@ -508,6 +593,9 @@ func parseDNS(cfg rawDNS) (*DNS, error) {
 		Listen:       cfg.Listen,
 		IPv6:         cfg.IPv6,
 		EnhancedMode: cfg.EnhancedMode,
+		FallbackFilter: FallbackFilter{
+			IPCIDR: []*net.IPNet{},
+		},
 	}
 	var err error
 	if dnsCfg.NameServer, err = parseNameServer(cfg.NameServer); err != nil {
@@ -523,7 +611,7 @@ func parseDNS(cfg rawDNS) (*DNS, error) {
 		if err != nil {
 			return nil, err
 		}
-		pool, err := fakeip.New(ipnet)
+		pool, err := fakeip.New(ipnet, 1000)
 		if err != nil {
 			return nil, err
 		}
@@ -531,6 +619,11 @@ func parseDNS(cfg rawDNS) (*DNS, error) {
 		dnsCfg.FakeIPRange = pool
 	}
 
+	dnsCfg.FallbackFilter.GeoIP = cfg.FallbackFilter.GeoIP
+	if fallbackip, err := parseFallbackIPCIDR(cfg.FallbackFilter.IPCIDR); err == nil {
+		dnsCfg.FallbackFilter.IPCIDR = fallbackip
+	}
+
 	return dnsCfg, nil
 }
 

config/utils.go

@@ -4,6 +4,8 @@ import (
 	"fmt"
 	"strings"
 
+	adapters "github.com/Dreamacro/clash/adapters/outbound"
+	"github.com/Dreamacro/clash/common/structure"
 	C "github.com/Dreamacro/clash/constant"
 )
 
@@ -34,3 +36,124 @@ func or(pointers ...*int) *int {
 	}
 	return pointers[len(pointers)-1]
 }
+
+// Check if ProxyGroups form DAG(Directed Acyclic Graph), and sort all ProxyGroups by dependency order.
+// Meanwhile, record the original index in the config file.
+// If loop is detected, return an error with location of loop.
+func proxyGroupsDagSort(groupsConfig []map[string]interface{}, decoder *structure.Decoder) error {
+
+	type graphNode struct {
+		indegree int
+		// topological order
+		topo int
+		// the origional data in `groupsConfig`
+		data map[string]interface{}
+		// `outdegree` and `from` are used in loop locating
+		outdegree int
+		from      []string
+	}
+
+	graph := make(map[string]*graphNode)
+
+	// Step 1.1 build dependency graph
+	for _, mapping := range groupsConfig {
+		option := &adapters.ProxyGroupOption{}
+		err := decoder.Decode(mapping, option)
+		groupName := option.Name
+		if err != nil {
+			return fmt.Errorf("ProxyGroup %s: %s", groupName, err.Error())
+		}
+
+		if node, ok := graph[groupName]; ok {
+			if node.data != nil {
+				return fmt.Errorf("ProxyGroup %s: duplicate group name", groupName)
+			}
+			node.data = mapping
+		} else {
+			graph[groupName] = &graphNode{0, -1, mapping, 0, nil}
+		}
+
+		for _, proxy := range option.Proxies {
+			if node, ex := graph[proxy]; ex {
+				node.indegree++
+			} else {
+				graph[proxy] = &graphNode{1, -1, nil, 0, nil}
+			}
+		}
+	}
+	// Step 1.2 Topological Sort
+	// topological index of **ProxyGroup**
+	index := 0
+	queue := make([]string, 0)
+	for name, node := range graph {
+		// in the begning, put nodes that have `node.indegree == 0` into queue.
+		if node.indegree == 0 {
+			queue = append(queue, name)
+		}
+	}
+	// every element in queue have indegree == 0
+	for ; len(queue) > 0; queue = queue[1:] {
+		name := queue[0]
+		node := graph[name]
+		if node.data != nil {
+			index++
+			groupsConfig[len(groupsConfig)-index] = node.data
+			for _, proxy := range node.data["proxies"].([]interface{}) {
+				child := graph[proxy.(string)]
+				child.indegree--
+				if child.indegree == 0 {
+					queue = append(queue, proxy.(string))
+				}
+			}
+		}
+		delete(graph, name)
+	}
+
+	// no loop is detected, return sorted ProxyGroup
+	if len(graph) == 0 {
+		return nil
+	}
+
+	// if loop is detected, locate the loop and throw an error
+	// Step 2.1 rebuild the graph, fill `outdegree` and `from` filed
+	for name, node := range graph {
+		if node.data == nil {
+			continue
+		}
+		for _, proxy := range node.data["proxies"].([]interface{}) {
+			node.outdegree++
+			child := graph[proxy.(string)]
+			if child.from == nil {
+				child.from = make([]string, 0, child.indegree)
+			}
+			child.from = append(child.from, name)
+		}
+	}
+	// Step 2.2 remove nodes outside the loop. so that we have only the loops remain in `graph`
+	queue = make([]string, 0)
+	// initialize queue with node have outdegree == 0
+	for name, node := range graph {
+		if node.outdegree == 0 {
+			queue = append(queue, name)
+		}
+	}
+	// every element in queue have outdegree == 0
+	for ; len(queue) > 0; queue = queue[1:] {
+		name := queue[0]
+		node := graph[name]
+		for _, f := range node.from {
+			graph[f].outdegree--
+			if graph[f].outdegree == 0 {
+				queue = append(queue, f)
+			}
+		}
+		delete(graph, name)
+	}
+	// Step 2.3 report the elements in loop
+	loopElements := make([]string, 0, len(graph))
+	for name := range graph {
+		loopElements = append(loopElements, name)
+		delete(graph, name)
+	}
+	return fmt.Errorf("Loop is detected in ProxyGroup, please check following ProxyGroups: %v", loopElements)
+}

constant/adapters.go

@@ -1,6 +1,8 @@
 package constant
 
 import (
+	"context"
+	"fmt"
 	"net"
 	"time"
 )
@@ -12,6 +14,7 @@ const (
 	Reject
 	Selector
 	Shadowsocks
+	Snell
 	Socks5
 	Http
 	URLTest
@@ -24,11 +27,39 @@ type ServerAdapter interface {
 	Metadata() *Metadata
 }
 
+type Connection interface {
+	Chains() Chain
+	AppendToChains(adapter ProxyAdapter)
+}
+
+type Chain []string
+
+func (c Chain) String() string {
+	switch len(c) {
+	case 0:
+		return ""
+	case 1:
+		return c[0]
+	default:
+		return fmt.Sprintf("%s[%s]", c[len(c)-1], c[0])
+	}
+}
+
+type Conn interface {
+	net.Conn
+	Connection
+}
+
+type PacketConn interface {
+	net.PacketConn
+	Connection
+}
+
 type ProxyAdapter interface {
 	Name() string
 	Type() AdapterType
-	Dial(metadata *Metadata) (net.Conn, error)
-	DialUDP(metadata *Metadata) (net.PacketConn, net.Addr, error)
+	DialContext(ctx context.Context, metadata *Metadata) (Conn, error)
+	DialUDP(metadata *Metadata) (PacketConn, net.Addr, error)
 	SupportUDP() bool
 	Destroy()
 	MarshalJSON() ([]byte, error)
@@ -43,8 +74,9 @@ type Proxy interface {
 	ProxyAdapter
 	Alive() bool
 	DelayHistory() []DelayHistory
+	Dial(metadata *Metadata) (Conn, error)
 	LastDelay() uint16
-	URLTest(url string) (uint16, error)
+	URLTest(ctx context.Context, url string) (uint16, error)
 }
 
 // AdapterType is enum of adapter type
@@ -62,6 +94,8 @@ func (at AdapterType) String() string {
 		return "Selector"
 	case Shadowsocks:
 		return "Shadowsocks"
+	case Snell:
+		return "Snell"
 	case Socks5:
 		return "Socks5"
 	case Http:
@@ -73,6 +107,6 @@ func (at AdapterType) String() string {
 	case LoadBalance:
 		return "LoadBalance"
 	default:
-		return "Unknow"
+		return "Unknown"
 	}
 }

constant/metadata.go

@@ -41,11 +41,18 @@ type Metadata struct {
 	Host     string
 }
 
+func (m *Metadata) RemoteAddress() string {
+	return net.JoinHostPort(m.String(), m.DstPort)
+}
+
 func (m *Metadata) String() string {
-	if m.Host == "" {
+	if m.Host != "" {
+		return m.Host
+	} else if m.DstIP != nil {
 		return m.DstIP.String()
+	} else {
+		return "<nil>"
 	}
-	return m.Host
 }
 
 func (m *Metadata) Valid() bool {

constant/path.go

@@ -2,7 +2,6 @@ package constant
 
 import (
 	"os"
-	"os/user"
 	P "path"
 )
 
@@ -16,16 +15,9 @@ type path struct {
 }
 
 func init() {
-	currentUser, err := user.Current()
-	var homedir string
+	homedir, err := os.UserHomeDir()
 	if err != nil {
-		dir := os.Getenv("HOME")
-		if dir == "" {
-			dir, _ = os.Getwd()
-		}
-		homedir = dir
-	} else {
-		homedir = currentUser.HomeDir
+		homedir, _ = os.Getwd()
 	}
 
 	homedir = P.Join(homedir, ".config", Name)

constant/rule.go

@@ -36,7 +36,7 @@ func (rt RuleType) String() string {
 	case MATCH:
 		return "MATCH"
 	default:
-		return "Unknow"
+		return "Unknown"
 	}
 }
 

dns/filters.go

@@ -0,0 +1,26 @@
+package dns
+
+import "net"
+
+type fallbackFilter interface {
+	Match(net.IP) bool
+}
+
+type geoipFilter struct{}
+
+func (gf *geoipFilter) Match(ip net.IP) bool {
+	if mmdb == nil {
+		return false
+	}
+
+	record, _ := mmdb.Country(ip)
+	return record.Country.IsoCode == "CN" || record.Country.IsoCode == ""
+}
+
+type ipnetFilter struct {
+	ipnet *net.IPNet
+}
+
+func (inf *ipnetFilter) Match(ip net.IP) bool {
+	return inf.ipnet.Contains(ip)
+}

dns/iputil.go

@@ -3,14 +3,88 @@ package dns
 import (
 	"errors"
 	"net"
+	"strings"
 )
 
 var (
 	errIPNotFound = errors.New("cannot found ip")
+	errIPVersion  = errors.New("ip version error")
 )
 
+// ResolveIPv4 with a host, return ipv4
+func ResolveIPv4(host string) (net.IP, error) {
+	if node := DefaultHosts.Search(host); node != nil {
+		if ip := node.Data.(net.IP).To4(); ip != nil {
+			return ip, nil
+		}
+	}
+
+	ip := net.ParseIP(host)
+	if ip != nil {
+		if !strings.Contains(host, ":") {
+			return ip, nil
+		}
+		return nil, errIPVersion
+	}
+
+	if DefaultResolver != nil {
+		return DefaultResolver.ResolveIPv4(host)
+	}
+
+	ipAddrs, err := net.LookupIP(host)
+	if err != nil {
+		return nil, err
+	}
+
+	for _, ip := range ipAddrs {
+		if ip4 := ip.To4(); ip4 != nil {
+			return ip4, nil
+		}
+	}
+
+	return nil, errIPNotFound
+}
+
+// ResolveIPv6 with a host, return ipv6
+func ResolveIPv6(host string) (net.IP, error) {
+	if node := DefaultHosts.Search(host); node != nil {
+		if ip := node.Data.(net.IP).To16(); ip != nil {
+			return ip, nil
+		}
+	}
+
+	ip := net.ParseIP(host)
+	if ip != nil {
+		if strings.Contains(host, ":") {
+			return ip, nil
+		}
+		return nil, errIPVersion
+	}
+
+	if DefaultResolver != nil {
+		return DefaultResolver.ResolveIPv6(host)
+	}
+
+	ipAddrs, err := net.LookupIP(host)
+	if err != nil {
+		return nil, err
+	}
+
+	for _, ip := range ipAddrs {
+		if ip.To4() == nil {
+			return ip, nil
+		}
+	}
+
+	return nil, errIPNotFound
+}
+
 // ResolveIP with a host, return ip
 func ResolveIP(host string) (net.IP, error) {
+	if node := DefaultHosts.Search(host); node != nil {
+		return node.Data.(net.IP), nil
+	}
+
 	if DefaultResolver != nil {
 		if DefaultResolver.ipv6 {
 			return DefaultResolver.ResolveIP(host)

dns/middleware.go

@@ -0,0 +1,79 @@
+package dns
+
+import (
+	"strings"
+
+	"github.com/Dreamacro/clash/component/fakeip"
+	"github.com/Dreamacro/clash/log"
+
+	D "github.com/miekg/dns"
+)
+
+type handler func(w D.ResponseWriter, r *D.Msg)
+type middleware func(next handler) handler
+
+func withFakeIP(fakePool *fakeip.Pool) middleware {
+	return func(next handler) handler {
+		return func(w D.ResponseWriter, r *D.Msg) {
+			q := r.Question[0]
+
+			if q.Qtype == D.TypeAAAA {
+				D.HandleFailed(w, r)
+				return
+			} else if q.Qtype != D.TypeA {
+				next(w, r)
+				return
+			}
+
+			host := strings.TrimRight(q.Name, ".")
+
+			rr := &D.A{}
+			rr.Hdr = D.RR_Header{Name: q.Name, Rrtype: D.TypeA, Class: D.ClassINET, Ttl: dnsDefaultTTL}
+			ip := fakePool.Lookup(host)
+			rr.A = ip
+			msg := r.Copy()
+			msg.Answer = []D.RR{rr}
+
+			setMsgTTL(msg, 1)
+			msg.SetReply(r)
+			w.WriteMsg(msg)
+			return
+		}
+	}
+}
+
+func withResolver(resolver *Resolver) handler {
+	return func(w D.ResponseWriter, r *D.Msg) {
+		msg, err := resolver.Exchange(r)
+		if err != nil {
+			q := r.Question[0]
+			log.Debugln("[DNS Server] Exchange %s failed: %v", q.String(), err)
+			D.HandleFailed(w, r)
+			return
+		}
+		msg.SetReply(r)
+		w.WriteMsg(msg)
+		return
+	}
+}
+
+func compose(middlewares []middleware, endpoint handler) handler {
+	length := len(middlewares)
+	h := endpoint
+	for i := length - 1; i >= 0; i-- {
+		middleware := middlewares[i]
+		h = middleware(h)
+	}
+
+	return h
+}
+
+func newHandler(resolver *Resolver) handler {
+	middlewares := []middleware{}
+
+	if resolver.IsFakeIP() {
+		middlewares = append(middlewares, withFakeIP(resolver.pool))
+	}
+
+	return compose(middlewares, withResolver(resolver))
+}

dns/resolver.go

@@ -11,16 +11,21 @@ import (
 
 	"github.com/Dreamacro/clash/common/cache"
 	"github.com/Dreamacro/clash/common/picker"
+	trie "github.com/Dreamacro/clash/component/domain-trie"
 	"github.com/Dreamacro/clash/component/fakeip"
 	C "github.com/Dreamacro/clash/constant"
 
 	D "github.com/miekg/dns"
 	geoip2 "github.com/oschwald/geoip2-golang"
+	"golang.org/x/sync/singleflight"
 )
 
 var (
-	// DefaultResolver aim to resolve ip with host
+	// DefaultResolver aim to resolve ip
 	DefaultResolver *Resolver
+
+	// DefaultHosts aim to resolve hosts
+	DefaultHosts = trie.New()
 )
 
 var (
@@ -41,22 +46,19 @@ type result struct {
 }
 
 type Resolver struct {
-	ipv6     bool
-	mapping  bool
-	fakeip   bool
-	pool     *fakeip.Pool
-	fallback []resolver
-	main     []resolver
-	cache    *cache.Cache
+	ipv6            bool
+	mapping         bool
+	fakeip          bool
+	pool            *fakeip.Pool
+	main            []resolver
+	fallback        []resolver
+	fallbackFilters []fallbackFilter
+	group           singleflight.Group
+	cache           *cache.Cache
 }
 
 // ResolveIP request with TypeA and TypeAAAA, priority return TypeAAAA
 func (r *Resolver) ResolveIP(host string) (ip net.IP, err error) {
-	ip = net.ParseIP(host)
-	if ip != nil {
-		return ip, nil
-	}
-
 	ch := make(chan net.IP)
 	go func() {
 		defer close(ch)
@@ -85,26 +87,21 @@ func (r *Resolver) ResolveIP(host string) (ip net.IP, err error) {
 
 // ResolveIPv4 request with TypeA
 func (r *Resolver) ResolveIPv4(host string) (ip net.IP, err error) {
-	ip = net.ParseIP(host)
-	if ip != nil {
-		return ip, nil
+	return r.resolveIP(host, D.TypeA)
+}
+
+// ResolveIPv6 request with TypeAAAA
+func (r *Resolver) ResolveIPv6(host string) (ip net.IP, err error) {
+	return r.resolveIP(host, D.TypeAAAA)
+}
+
+func (r *Resolver) shouldFallback(ip net.IP) bool {
+	for _, filter := range r.fallbackFilters {
+		if filter.Match(ip) {
+			return true
+		}
 	}
-
-	query := &D.Msg{}
-	query.SetQuestion(D.Fqdn(host), D.TypeA)
-
-	msg, err := r.Exchange(query)
-	if err != nil {
-		return nil, err
-	}
-
-	ips := r.msgToIP(msg)
-	if len(ips) == 0 {
-		return nil, errIPNotFound
-	}
-
-	ip = ips[0]
-	return
+	return false
 }
 
 // Exchange a batch of dns request, and it use cache
@@ -134,18 +131,29 @@ func (r *Resolver) Exchange(m *D.Msg) (msg *D.Msg, err error) {
 		}
 	}()
 
-	isIPReq := isIPRequest(q)
-	if isIPReq {
-		msg, err = r.fallbackExchange(m)
-		return
+	ret, err, _ := r.group.Do(q.String(), func() (interface{}, error) {
+		isIPReq := isIPRequest(q)
+		if isIPReq {
+			msg, err := r.fallbackExchange(m)
+			return msg, err
+		}
+
+		return r.batchExchange(r.main, m)
+	})
+
+	if err == nil {
+		msg = ret.(*D.Msg)
 	}
 
-	msg, err = r.batchExchange(r.main, m)
 	return
 }
 
 // IPToHost return fake-ip or redir-host mapping host
 func (r *Resolver) IPToHost(ip net.IP) (string, bool) {
+	if r.fakeip {
+		return r.pool.LookBack(ip)
+	}
+
 	cache := r.cache.Get(ip.String())
 	if cache == nil {
 		return "", false
@@ -163,32 +171,20 @@ func (r *Resolver) IsFakeIP() bool {
 }
 
 func (r *Resolver) batchExchange(clients []resolver, 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(clients))
-	for _, r := range clients {
-		go func(r resolver) {
-			defer wg.Done()
+	fast, ctx := picker.WithTimeout(context.Background(), time.Second)
+	for _, client := range clients {
+		r := client
+		fast.Go(func() (interface{}, error) {
 			msg, err := r.ExchangeContext(ctx, m)
 			if err != nil || msg.Rcode != D.RcodeSuccess {
-				return
+				return nil, errors.New("resolve error")
 			}
-			in <- msg
-		}(r)
+			return msg, nil
+		})
 	}
 
-	// release in channel
-	go func() {
-		wg.Wait()
-		close(in)
-	}()
-
-	elm, exist := <-fast
-	if !exist {
+	elm := fast.Wait()
+	if elm == nil {
 		return nil, errors.New("All DNS requests failed")
 	}
 
@@ -206,13 +202,8 @@ func (r *Resolver) fallbackExchange(m *D.Msg) (msg *D.Msg, err error) {
 	fallbackMsg := r.asyncExchange(r.fallback, m)
 	res := <-msgCh
 	if res.Error == nil {
-		if mmdb == nil {
-			return nil, errors.New("GeoIP cannot use")
-		}
-
 		if ips := r.msgToIP(res.Msg); len(ips) != 0 {
-			if record, _ := mmdb.Country(ips[0]); record.Country.IsoCode == "CN" || record.Country.IsoCode == "" {
-				// release channel
+			if r.shouldFallback(ips[0]) {
 				go func() { <-fallbackMsg }()
 				msg = res.Msg
 				return msg, err
@@ -226,6 +217,16 @@ func (r *Resolver) fallbackExchange(m *D.Msg) (msg *D.Msg, err error) {
 }
 
 func (r *Resolver) resolveIP(host string, dnsType uint16) (ip net.IP, err error) {
+	ip = net.ParseIP(host)
+	if ip != nil {
+		isIPv4 := ip.To4() != nil
+		if dnsType == D.TypeAAAA && !isIPv4 {
+			return ip, nil
+		} else if dnsType == D.TypeA && isIPv4 {
+			return ip, nil
+		}
+	}
+
 	query := &D.Msg{}
 	query.SetQuestion(D.Fqdn(host), dnsType)
 
@@ -272,18 +273,20 @@ type NameServer struct {
 	Addr string
 }
 
+type FallbackFilter struct {
+	GeoIP  bool
+	IPCIDR []*net.IPNet
+}
+
 type Config struct {
 	Main, Fallback []NameServer
 	IPv6           bool
 	EnhancedMode   EnhancedMode
+	FallbackFilter FallbackFilter
 	Pool           *fakeip.Pool
 }
 
 func New(config Config) *Resolver {
-	once.Do(func() {
-		mmdb, _ = geoip2.Open(C.Path.MMDB())
-	})
-
 	r := &Resolver{
 		ipv6:    config.IPv6,
 		main:    transform(config.Main),
@@ -292,8 +295,23 @@ func New(config Config) *Resolver {
 		fakeip:  config.EnhancedMode == FAKEIP,
 		pool:    config.Pool,
 	}
+
 	if len(config.Fallback) != 0 {
 		r.fallback = transform(config.Fallback)
 	}
+
+	fallbackFilters := []fallbackFilter{}
+	if config.FallbackFilter.GeoIP {
+		once.Do(func() {
+			mmdb, _ = geoip2.Open(C.Path.MMDB())
+		})
+
+		fallbackFilters = append(fallbackFilters, &geoipFilter{})
+	}
+	for _, ipnet := range config.FallbackFilter.IPCIDR {
+		fallbackFilters = append(fallbackFilters, &ipnetFilter{ipnet: ipnet})
+	}
+	r.fallbackFilters = fallbackFilters
+
 	return r
 }

dns/server.go

@@ -1,12 +1,8 @@
 package dns
 
 import (
-	"errors"
-	"fmt"
 	"net"
 
-	"github.com/Dreamacro/clash/log"
-	"github.com/miekg/dns"
 	D "github.com/miekg/dns"
 )
 
@@ -19,79 +15,26 @@ var (
 
 type Server struct {
 	*D.Server
-	r *Resolver
+	handler handler
 }
 
 func (s *Server) ServeDNS(w D.ResponseWriter, r *D.Msg) {
-	if s.r.IsFakeIP() {
-		msg, err := s.handleFakeIP(r)
-		if err != nil {
-			D.HandleFailed(w, r)
-			return
-		}
-		msg.SetReply(r)
-		w.WriteMsg(msg)
-		return
-	}
-
-	msg, err := s.r.Exchange(r)
-
-	if err != nil {
-		if len(r.Question) > 0 {
-			q := r.Question[0]
-			qString := fmt.Sprintf("%s %s %s", q.Name, D.Class(q.Qclass).String(), D.Type(q.Qtype).String())
-			log.Debugln("[DNS Server] Exchange %s failed: %v", qString, err)
-		}
+	if len(r.Question) == 0 {
 		D.HandleFailed(w, r)
 		return
 	}
-	msg.SetReply(r)
-	w.WriteMsg(msg)
+
+	s.handler(w, r)
 }
 
-func (s *Server) handleFakeIP(r *D.Msg) (msg *D.Msg, err error) {
-	if len(r.Question) == 0 {
-		err = errors.New("should have one question at least")
-		return
-	}
-
-	q := r.Question[0]
-
-	cache := s.r.cache.Get("fakeip:" + q.String())
-	if cache != nil {
-		msg = cache.(*D.Msg).Copy()
-		setMsgTTL(msg, 1)
-		return
-	}
-
-	var ip net.IP
-	defer func() {
-		if msg == nil {
-			return
-		}
-
-		putMsgToCache(s.r.cache, "fakeip:"+q.String(), msg)
-		putMsgToCache(s.r.cache, ip.String(), msg)
-
-		setMsgTTL(msg, 1)
-	}()
-
-	rr := &D.A{}
-	rr.Hdr = dns.RR_Header{Name: r.Question[0].Name, Rrtype: dns.TypeA, Class: dns.ClassINET, Ttl: dnsDefaultTTL}
-	ip = s.r.pool.Get()
-	rr.A = ip
-	msg = r.Copy()
-	msg.Answer = []D.RR{rr}
-	return
-}
-
-func (s *Server) setReslover(r *Resolver) {
-	s.r = r
+func (s *Server) setHandler(handler handler) {
+	s.handler = handler
 }
 
 func ReCreateServer(addr string, resolver *Resolver) error {
-	if addr == address {
-		server.setReslover(resolver)
+	if addr == address && resolver != nil {
+		handler := newHandler(resolver)
+		server.setHandler(handler)
 		return nil
 	}
 
@@ -116,7 +59,8 @@ func ReCreateServer(addr string, resolver *Resolver) error {
 	}
 
 	address = addr
-	server = &Server{r: resolver}
+	handler := newHandler(resolver)
+	server = &Server{handler: handler}
 	server.Server = &D.Server{Addr: addr, PacketConn: p, Handler: server}
 
 	go func() {

go.mod

@@ -1,20 +1,23 @@
 module github.com/Dreamacro/clash
 
+go 1.13
+
 require (
-	github.com/Dreamacro/go-shadowsocks2 v0.1.3
+	github.com/Dreamacro/go-shadowsocks2 v0.1.5-0.20191012162057-46254afc8b68
 	github.com/eapache/queue v1.1.0 // indirect
 	github.com/go-chi/chi v4.0.2+incompatible
 	github.com/go-chi/cors v1.0.0
 	github.com/go-chi/render v1.0.1
 	github.com/gofrs/uuid v3.2.0+incompatible
-	github.com/gorilla/websocket v1.4.0
-	github.com/miekg/dns v1.1.14
+	github.com/gorilla/websocket v1.4.1
+	github.com/miekg/dns v1.1.22
 	github.com/oschwald/geoip2-golang v1.3.0
-	github.com/oschwald/maxminddb-golang v1.3.1 // indirect
+	github.com/oschwald/maxminddb-golang v1.5.0 // indirect
 	github.com/sirupsen/logrus v1.4.2
-	golang.org/x/crypto v0.0.0-20190426145343-a29dc8fdc734
-	golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3
-	golang.org/x/sync v0.0.0-20190423024810-112230192c58 // indirect
+	github.com/stretchr/testify v1.4.0
+	golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550
+	golang.org/x/net v0.0.0-20191011234655-491137f69257
+	golang.org/x/sync v0.0.0-20190911185100-cd5d95a43a6e
 	gopkg.in/eapache/channels.v1 v1.1.0
 	gopkg.in/yaml.v2 v2.2.2
 )

go.sum

@@ -1,7 +1,8 @@
-github.com/Dreamacro/go-shadowsocks2 v0.1.3 h1:1ffY/q4e3o+MnztYgIq1iZiX1BWoWQ6D3AIO1kkb8bc=
-github.com/Dreamacro/go-shadowsocks2 v0.1.3/go.mod h1:0x17IhQ+mlY6q/ffKRpzaE7u4aHMxxnitTRSrV5G6TU=
+github.com/Dreamacro/go-shadowsocks2 v0.1.5-0.20191012162057-46254afc8b68 h1:UBDLpj1IGVkUcUBuZWE6DmZApPTZcnmcV6AfyDN/yhg=
+github.com/Dreamacro/go-shadowsocks2 v0.1.5-0.20191012162057-46254afc8b68/go.mod h1:Y8obOtHDOqxMGHjPglfCiXZBKExOA9VL6I6sJagOwYM=
 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 v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/eapache/queue v1.1.0 h1:YOEu7KNc61ntiQlcEeUIoDTJ2o8mQznoNvUhiigpIqc=
@@ -14,36 +15,56 @@ github.com/go-chi/render v1.0.1 h1:4/5tis2cKaNdnv9zFLfXzcquC9HbeZgCnxGnKrltBS8=
 github.com/go-chi/render v1.0.1/go.mod h1:pq4Rr7HbnsdaeHagklXub+p6Wd16Af5l9koip1OvJns=
 github.com/gofrs/uuid v3.2.0+incompatible h1:y12jRkkFxsd7GpqdSZ+/KCs/fJbqpEXSGd4+jfEaewE=
 github.com/gofrs/uuid v3.2.0+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/gorilla/websocket v1.4.1 h1:q7AeDBpnBk8AogcD4DSag/Ukw/KV+YhzLj2bP5HvKCM=
+github.com/gorilla/websocket v1.4.1/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=
 github.com/konsorten/go-windows-terminal-sequences v1.0.1 h1:mweAR1A6xJ3oS2pRaGiHgQ4OO8tzTaLawm8vnODuwDk=
 github.com/konsorten/go-windows-terminal-sequences v1.0.1/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
-github.com/miekg/dns v1.1.14 h1:wkQWn9wIp4mZbwW8XV6Km6owkvRPbOiV004ZM2CkGvA=
-github.com/miekg/dns v1.1.14/go.mod h1:W1PPwlIAgtquWBMBEV9nkV9Cazfe8ScdGz/Lj7v3Nrg=
+github.com/miekg/dns v1.1.22 h1:Jm64b3bO9kP43ddLjL2EY3Io6bmy1qGb9Xxz6TqS6rc=
+github.com/miekg/dns v1.1.22/go.mod h1:bPDLeHnStXmXAq1m/Ch/hvfNHr14JKNPMBo3VZKjuso=
 github.com/oschwald/geoip2-golang v1.3.0 h1:D+Hsdos1NARPbzZ2aInUHZL+dApIzo8E0ErJVsWcku8=
 github.com/oschwald/geoip2-golang v1.3.0/go.mod h1:0LTTzix/Ao1uMvOhAV4iLU0Lz7eCrP94qZWBTDKf0iE=
-github.com/oschwald/maxminddb-golang v1.3.1 h1:kPc5+ieL5CC/Zn0IaXJPxDFlUxKTQEU8QBTtmfQDAIo=
-github.com/oschwald/maxminddb-golang v1.3.1/go.mod h1:3jhIUymTJ5VREKyIhWm66LJiQt04F0UCDdodShpjWsY=
+github.com/oschwald/maxminddb-golang v1.5.0 h1:rmyoIV6z2/s9TCJedUuDiKht2RN12LWJ1L7iRGtWY64=
+github.com/oschwald/maxminddb-golang v1.5.0/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 v1.4.2 h1:SPIRibHv4MatM3XXNO2BJeFLZwZ2LvZgfQ5+UNI2im4=
 github.com/sirupsen/logrus v1.4.2/go.mod h1:tLMulIdttU9McNUspp0xgXVQah82FyeX6MwdIuYE2rE=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/objx v0.1.1 h1:2vfRuCMp5sSVIDSqO8oNnWJq7mPa6KVP3iPIwFBuy8A=
 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=
+github.com/stretchr/testify v1.4.0 h1:2E4SXV/wtOkTonXsotYi4li6zVWxYlZuYNCXe9XRJyk=
+github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
-golang.org/x/crypto v0.0.0-20190426145343-a29dc8fdc734 h1:p/H982KKEjUnLJkM3tt/LemDnOc1GiZL5FCVlORJ5zo=
-golang.org/x/crypto v0.0.0-20190426145343-a29dc8fdc734/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
+golang.org/x/crypto v0.0.0-20190923035154-9ee001bba392 h1:ACG4HJsFiNMf47Y4PeRoebLNy/2lXT9EtprMuTFWt1M=
+golang.org/x/crypto v0.0.0-20190923035154-9ee001bba392/go.mod h1:/lpIB1dKB+9EgE3H3cr1v9wB50oz8l4C4h62xy7jSTY=
+golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550 h1:ObdrDkeb4kJdCP557AjRjq69pTHfNouLtWZG7j9rPN8=
+golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3 h1:0GoQqolDA55aaLxZyTzK/Y2ePZzZTUrRacwib7cNsYQ=
 golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
+golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
+golang.org/x/net v0.0.0-20190923162816-aa69164e4478 h1:l5EDrHhldLYb3ZRHDUhXF7Om7MvYXnkV9/iQNo1lX6g=
+golang.org/x/net v0.0.0-20190923162816-aa69164e4478/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
+golang.org/x/net v0.0.0-20191011234655-491137f69257 h1:ry8e2D+cwaV6hk7lb3aRTjjZo24shrbK0e11QEOkTIg=
+golang.org/x/net v0.0.0-20191011234655-491137f69257/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
 golang.org/x/sync v0.0.0-20190423024810-112230192c58 h1:8gQV6CLnAEikrhgkHFbMAEhagSSnXWGV915qUMm9mrU=
 golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20190911185100-cd5d95a43a6e h1:vcxGaoTs7kV8m5Np9uUNQin4BrLOthgV7252N8V+FwY=
+golang.org/x/sync v0.0.0-20190911185100-cd5d95a43a6e/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190412213103-97732733099d h1:+R4KGOnez64A81RvjARKc4UT5/tI9ujCIVX+P5KiHuI=
 golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20190422165155-953cdadca894 h1:Cz4ceDQGXuKRnVBDTS23GTn/pU5OE2C0WrNTOYK1Uuc=
 golang.org/x/sys v0.0.0-20190422165155-953cdadca894/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20190922100055-0a153f010e69/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20190924154521-2837fb4f24fe h1:6fAMxZRR6sl1Uq8U61gxU+kPTs2tR8uOySCbBP7BN/M=
+golang.org/x/sys v0.0.0-20190924154521-2837fb4f24fe/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+golang.org/x/text v0.3.2/go.mod h1:bEr9sfX3Q8Zfm5fL9x+3itogRgK3+ptLWKqgva+5dAk=
+golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
+golang.org/x/tools v0.0.0-20190907020128-2ca718005c18/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
+golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 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=

hub/executor/executor.go

@@ -2,6 +2,7 @@ package executor
 
 import (
 	"github.com/Dreamacro/clash/component/auth"
+	trie "github.com/Dreamacro/clash/component/domain-trie"
 	"github.com/Dreamacro/clash/config"
 	C "github.com/Dreamacro/clash/constant"
 	"github.com/Dreamacro/clash/dns"
@@ -30,6 +31,7 @@ func ApplyConfig(cfg *config.Config, force bool) {
 	updateProxies(cfg.Proxies)
 	updateRules(cfg.Rules)
 	updateDNS(cfg.DNS)
+	updateHosts(cfg.Hosts)
 	updateExperimental(cfg.Experimental)
 }
 
@@ -46,6 +48,7 @@ func GetGeneral() *config.General {
 		RedirPort:      ports.RedirPort,
 		Authentication: authenticator,
 		AllowLan:       P.AllowLan(),
+		BindAddress:    P.BindAddress(),
 		Mode:           T.Instance().Mode(),
 		LogLevel:       log.Level(),
 	}
@@ -69,6 +72,10 @@ func updateDNS(c *config.DNS) {
 		IPv6:         c.IPv6,
 		EnhancedMode: c.EnhancedMode,
 		Pool:         c.FakeIPRange,
+		FallbackFilter: dns.FallbackFilter{
+			GeoIP:  c.FallbackFilter.GeoIP,
+			IPCIDR: c.FallbackFilter.IPCIDR,
+		},
 	})
 	dns.DefaultResolver = r
 	if err := dns.ReCreateServer(c.Listen, r); err != nil {
@@ -81,6 +88,10 @@ func updateDNS(c *config.DNS) {
 	}
 }
 
+func updateHosts(tree *trie.Trie) {
+	dns.DefaultHosts = tree
+}
+
 func updateProxies(proxies map[string]C.Proxy) {
 	tunnel := T.Instance()
 	oldProxies := tunnel.Proxies()
@@ -102,9 +113,11 @@ func updateGeneral(general *config.General) {
 	T.Instance().SetMode(general.Mode)
 
 	allowLan := general.AllowLan
-
 	P.SetAllowLan(allowLan)
 
+	bindAddress := general.BindAddress
+	P.SetBindAddress(bindAddress)
+
 	if err := P.ReCreateHTTP(general.Port); err != nil {
 		log.Errorln("Start HTTP server error: %s", err.Error())
 	}

hub/route/configs.go

@@ -22,12 +22,13 @@ func configRouter() http.Handler {
 }
 
 type configSchema struct {
-	Port      *int          `json:"port"`
-	SocksPort *int          `json:"socks-port"`
-	RedirPort *int          `json:"redir-port"`
-	AllowLan  *bool         `json:"allow-lan"`
-	Mode      *T.Mode       `json:"mode"`
-	LogLevel  *log.LogLevel `json:"log-level"`
+	Port        *int          `json:"port"`
+	SocksPort   *int          `json:"socks-port"`
+	RedirPort   *int          `json:"redir-port"`
+	AllowLan    *bool         `json:"allow-lan"`
+	BindAddress *string       `json:"bind-address"`
+	Mode        *T.Mode       `json:"mode"`
+	LogLevel    *log.LogLevel `json:"log-level"`
 }
 
 func getConfigs(w http.ResponseWriter, r *http.Request) {
@@ -55,6 +56,10 @@ func patchConfigs(w http.ResponseWriter, r *http.Request) {
 		P.SetAllowLan(*general.AllowLan)
 	}
 
+	if general.BindAddress != nil {
+		P.SetBindAddress(*general.BindAddress)
+	}
+
 	ports := P.GetPorts()
 	P.ReCreateHTTP(pointerOrDefault(general.Port, ports.Port))
 	P.ReCreateSocks(pointerOrDefault(general.SocksPort, ports.SocksPort))

hub/route/proxies.go

@@ -110,27 +110,23 @@ func getProxyDelay(w http.ResponseWriter, r *http.Request) {
 
 	proxy := r.Context().Value(CtxKeyProxy).(C.Proxy)
 
-	sigCh := make(chan uint16)
-	go func() {
-		t, err := proxy.URLTest(url)
-		if err != nil {
-			sigCh <- 0
-		}
-		sigCh <- t
-	}()
+	ctx, cancel := context.WithTimeout(context.Background(), time.Millisecond*time.Duration(timeout))
+	defer cancel()
 
-	select {
-	case <-time.After(time.Millisecond * time.Duration(timeout)):
-		render.Status(r, http.StatusRequestTimeout)
+	delay, err := proxy.URLTest(ctx, url)
+	if ctx.Err() != nil {
+		render.Status(r, http.StatusGatewayTimeout)
 		render.JSON(w, r, ErrRequestTimeout)
-	case t := <-sigCh:
-		if t == 0 {
-			render.Status(r, http.StatusServiceUnavailable)
-			render.JSON(w, r, newError("An error occurred in the delay test"))
-		} else {
-			render.JSON(w, r, render.M{
-				"delay": t,
-			})
-		}
+		return
 	}
+
+	if err != nil || delay == 0 {
+		render.Status(r, http.StatusServiceUnavailable)
+		render.JSON(w, r, newError("An error occurred in the delay test"))
+		return
+	}
+
+	render.JSON(w, r, render.M{
+		"delay": delay,
+	})
 }

hub/route/server.go

@@ -1,17 +1,20 @@
 package route
 
 import (
+	"bytes"
 	"encoding/json"
 	"net/http"
 	"strings"
 	"time"
 
+	C "github.com/Dreamacro/clash/constant"
 	"github.com/Dreamacro/clash/log"
 	T "github.com/Dreamacro/clash/tunnel"
 
 	"github.com/go-chi/chi"
 	"github.com/go-chi/cors"
 	"github.com/go-chi/render"
+	"github.com/gorilla/websocket"
 )
 
 var (
@@ -19,6 +22,12 @@ var (
 	serverAddr   = ""
 
 	uiPath = ""
+
+	upgrader = websocket.Upgrader{
+		CheckOrigin: func(r *http.Request) bool {
+			return true
+		},
+	}
 )
 
 type Traffic struct {
@@ -47,15 +56,14 @@ func Start(addr string, secret string) {
 		MaxAge:         300,
 	})
 
-	root := chi.NewRouter().With(jsonContentType)
-	root.Get("/traffic", traffic)
-	root.Get("/logs", getLogs)
-
+	r.Use(cors.Handler)
 	r.Get("/", hello)
 	r.Group(func(r chi.Router) {
-		r.Use(cors.Handler, authentication)
+		r.Use(authentication)
 
-		r.Mount("/", root)
+		r.Get("/logs", getLogs)
+		r.Get("/traffic", traffic)
+		r.Get("/version", version)
 		r.Mount("/configs", configRouter())
 		r.Mount("/proxies", proxyRouter())
 		r.Mount("/rules", ruleRouter())
@@ -64,7 +72,7 @@ func Start(addr string, secret string) {
 	if uiPath != "" {
 		r.Group(func(r chi.Router) {
 			fs := http.StripPrefix("/ui", http.FileServer(http.Dir(uiPath)))
-			r.Get("/ui", http.RedirectHandler("/ui/", 301).ServeHTTP)
+			r.Get("/ui", http.RedirectHandler("/ui/", http.StatusTemporaryRedirect).ServeHTTP)
 			r.Get("/ui/*", func(w http.ResponseWriter, r *http.Request) {
 				fs.ServeHTTP(w, r)
 			})
@@ -78,24 +86,28 @@ func Start(addr string, secret string) {
 	}
 }
 
-func jsonContentType(next http.Handler) http.Handler {
-	fn := func(w http.ResponseWriter, r *http.Request) {
-		w.Header().Set("Content-Type", "application/json")
-		next.ServeHTTP(w, r)
-	}
-	return http.HandlerFunc(fn)
-}
-
 func authentication(next http.Handler) http.Handler {
 	fn := func(w http.ResponseWriter, r *http.Request) {
-		header := r.Header.Get("Authorization")
-		text := strings.SplitN(header, " ", 2)
-
 		if serverSecret == "" {
 			next.ServeHTTP(w, r)
 			return
 		}
 
+		// Browser websocket not support custom header
+		if websocket.IsWebSocketUpgrade(r) && r.URL.Query().Get("token") != "" {
+			token := r.URL.Query().Get("token")
+			if token != serverSecret {
+				render.Status(r, http.StatusUnauthorized)
+				render.JSON(w, r, ErrUnauthorized)
+				return
+			}
+			next.ServeHTTP(w, r)
+			return
+		}
+
+		header := r.Header.Get("Authorization")
+		text := strings.SplitN(header, " ", 2)
+
 		hasUnvalidHeader := text[0] != "Bearer"
 		hasUnvalidSecret := len(text) == 2 && text[1] != serverSecret
 		if hasUnvalidHeader || hasUnvalidSecret {
@@ -113,19 +125,44 @@ func hello(w http.ResponseWriter, r *http.Request) {
 }
 
 func traffic(w http.ResponseWriter, r *http.Request) {
-	render.Status(r, http.StatusOK)
+	var wsConn *websocket.Conn
+	if websocket.IsWebSocketUpgrade(r) {
+		var err error
+		wsConn, err = upgrader.Upgrade(w, r, nil)
+		if err != nil {
+			return
+		}
+	}
+
+	if wsConn == nil {
+		w.Header().Set("Content-Type", "application/json")
+		render.Status(r, http.StatusOK)
+	}
 
 	tick := time.NewTicker(time.Second)
 	t := T.Instance().Traffic()
+	buf := &bytes.Buffer{}
+	var err error
 	for range tick.C {
+		buf.Reset()
 		up, down := t.Now()
-		if err := json.NewEncoder(w).Encode(Traffic{
+		if err := json.NewEncoder(buf).Encode(Traffic{
 			Up:   up,
 			Down: down,
 		}); err != nil {
 			break
 		}
-		w.(http.Flusher).Flush()
+
+		if wsConn == nil {
+			_, err = w.Write(buf.Bytes())
+			w.(http.Flusher).Flush()
+		} else {
+			err = wsConn.WriteMessage(websocket.TextMessage, buf.Bytes())
+		}
+
+		if err != nil {
+			break
+		}
 	}
 }
 
@@ -147,20 +184,51 @@ func getLogs(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	var wsConn *websocket.Conn
+	if websocket.IsWebSocketUpgrade(r) {
+		var err error
+		wsConn, err = upgrader.Upgrade(w, r, nil)
+		if err != nil {
+			return
+		}
+	}
+
+	if wsConn == nil {
+		w.Header().Set("Content-Type", "application/json")
+		render.Status(r, http.StatusOK)
+	}
+
 	sub := log.Subscribe()
-	render.Status(r, http.StatusOK)
+	defer log.UnSubscribe(sub)
+	buf := &bytes.Buffer{}
+	var err error
 	for elm := range sub {
+		buf.Reset()
 		log := elm.(*log.Event)
 		if log.LogLevel < level {
 			continue
 		}
 
-		if err := json.NewEncoder(w).Encode(Log{
+		if err := json.NewEncoder(buf).Encode(Log{
 			Type:    log.Type(),
 			Payload: log.Payload,
 		}); err != nil {
 			break
 		}
-		w.(http.Flusher).Flush()
+
+		if wsConn == nil {
+			_, err = w.Write(buf.Bytes())
+			w.(http.Flusher).Flush()
+		} else {
+			err = wsConn.WriteMessage(websocket.TextMessage, buf.Bytes())
+		}
+
+		if err != nil {
+			break
+		}
 	}
 }
+
+func version(w http.ResponseWriter, r *http.Request) {
+	render.JSON(w, r, render.M{"version": C.Version})
+}

log/log.go

@@ -62,6 +62,11 @@ func Subscribe() observable.Subscription {
 	return sub
 }
 
+func UnSubscribe(sub observable.Subscription) {
+	source.UnSubscribe(sub)
+	return
+}
+
 func Level() LogLevel {
 	return level
 }

main.go

@@ -33,9 +33,6 @@ func main() {
 		return
 	}
 
-	// enable tls 1.3 and remove when go 1.13
-	os.Setenv("GODEBUG", os.Getenv("GODEBUG")+",tls13=1")
-
 	if homedir != "" {
 		if !filepath.IsAbs(homedir) {
 			currentDir, _ := os.Getwd()

proxy/listener.go

@@ -11,11 +11,13 @@ import (
 )
 
 var (
-	allowLan = false
+	allowLan    = false
+	bindAddress = "*"
 
-	socksListener *socks.SockListener
-	httpListener  *http.HttpListener
-	redirListener *redir.RedirListener
+	socksListener    *socks.SockListener
+	socksUDPListener *socks.SockUDPListener
+	httpListener     *http.HttpListener
+	redirListener    *redir.RedirListener
 )
 
 type listener interface {
@@ -33,12 +35,20 @@ func AllowLan() bool {
 	return allowLan
 }
 
+func BindAddress() string {
+	return bindAddress
+}
+
 func SetAllowLan(al bool) {
 	allowLan = al
 }
 
+func SetBindAddress(host string) {
+	bindAddress = host
+}
+
 func ReCreateHTTP(port int) error {
-	addr := genAddr(port, allowLan)
+	addr := genAddr(bindAddress, port, allowLan)
 
 	if httpListener != nil {
 		if httpListener.Address() == addr {
@@ -62,7 +72,7 @@ func ReCreateHTTP(port int) error {
 }
 
 func ReCreateSocks(port int) error {
-	addr := genAddr(port, allowLan)
+	addr := genAddr(bindAddress, port, allowLan)
 
 	if socksListener != nil {
 		if socksListener.Address() == addr {
@@ -82,11 +92,29 @@ func ReCreateSocks(port int) error {
 		return err
 	}
 
+	return reCreateSocksUDP(addr)
+}
+
+func reCreateSocksUDP(addr string) error {
+	if socksUDPListener != nil {
+		if socksUDPListener.Address() == addr {
+			return nil
+		}
+		socksUDPListener.Close()
+		socksUDPListener = nil
+	}
+
+	var err error
+	socksUDPListener, err = socks.NewSocksUDPProxy(addr)
+	if err != nil {
+		return err
+	}
+
 	return nil
 }
 
 func ReCreateRedir(port int) error {
-	addr := genAddr(port, allowLan)
+	addr := genAddr(bindAddress, port, allowLan)
 
 	if redirListener != nil {
 		if redirListener.Address() == addr {
@@ -142,9 +170,14 @@ func portIsZero(addr string) bool {
 	return false
 }
 
-func genAddr(port int, allowLan bool) string {
+func genAddr(host string, port int, allowLan bool) string {
 	if allowLan {
-		return fmt.Sprintf(":%d", port)
+		if host == "*" {
+			return fmt.Sprintf(":%d", port)
+		} else {
+			return fmt.Sprintf("%s:%d", host, port)
+		}
 	}
+
 	return fmt.Sprintf("127.0.0.1:%d", port)
 }

proxy/socks/tcp.go

@@ -1,6 +1,8 @@
 package socks
 
 import (
+	"io"
+	"io/ioutil"
 	"net"
 
 	adapters "github.com/Dreamacro/clash/adapters/inbound"
@@ -62,7 +64,8 @@ func handleSocks(conn net.Conn) {
 	}
 	conn.(*net.TCPConn).SetKeepAlive(true)
 	if command == socks5.CmdUDPAssociate {
-		tun.Add(adapters.NewSocket(target, conn, C.SOCKS, C.UDP))
+		defer conn.Close()
+		io.Copy(ioutil.Discard, conn)
 		return
 	}
 	tun.Add(adapters.NewSocket(target, conn, C.SOCKS, C.TCP))

proxy/socks/udp.go

@@ -0,0 +1,68 @@
+package socks
+
+import (
+	"bytes"
+	"net"
+
+	adapters "github.com/Dreamacro/clash/adapters/inbound"
+	"github.com/Dreamacro/clash/common/pool"
+	"github.com/Dreamacro/clash/component/socks5"
+	C "github.com/Dreamacro/clash/constant"
+)
+
+type SockUDPListener struct {
+	net.PacketConn
+	address string
+	closed  bool
+}
+
+func NewSocksUDPProxy(addr string) (*SockUDPListener, error) {
+	l, err := net.ListenPacket("udp", addr)
+	if err != nil {
+		return nil, err
+	}
+
+	sl := &SockUDPListener{l, addr, false}
+	go func() {
+		for {
+			buf := pool.BufPool.Get().([]byte)
+			n, remoteAddr, err := l.ReadFrom(buf)
+			if err != nil {
+				pool.BufPool.Put(buf[:cap(buf)])
+				if sl.closed {
+					break
+				}
+				continue
+			}
+			handleSocksUDP(l, buf[:n], remoteAddr)
+		}
+	}()
+
+	return sl, nil
+}
+
+func (l *SockUDPListener) Close() error {
+	l.closed = true
+	return l.PacketConn.Close()
+}
+
+func (l *SockUDPListener) Address() string {
+	return l.address
+}
+
+func handleSocksUDP(pc net.PacketConn, buf []byte, addr net.Addr) {
+	target, payload, err := socks5.DecodeUDPPacket(buf)
+	if err != nil {
+		// Unresolved UDP packet, return buffer to the pool
+		pool.BufPool.Put(buf[:cap(buf)])
+		return
+	}
+	conn := &fakeConn{
+		PacketConn: pc,
+		remoteAddr: addr,
+		targetAddr: target,
+		buffer:     bytes.NewBuffer(payload),
+		bufRef:     buf,
+	}
+	tun.Add(adapters.NewSocket(target, conn, C.SOCKS, C.UDP))
+}

proxy/socks/utils.go

@@ -0,0 +1,39 @@
+package socks
+
+import (
+	"bytes"
+	"net"
+
+	"github.com/Dreamacro/clash/common/pool"
+	"github.com/Dreamacro/clash/component/socks5"
+)
+
+type fakeConn struct {
+	net.PacketConn
+	remoteAddr net.Addr
+	targetAddr socks5.Addr
+	buffer     *bytes.Buffer
+	bufRef     []byte
+}
+
+func (c *fakeConn) Read(b []byte) (n int, err error) {
+	return c.buffer.Read(b)
+}
+
+func (c *fakeConn) Write(b []byte) (n int, err error) {
+	packet, err := socks5.EncodeUDPPacket(c.targetAddr, b)
+	if err != nil {
+		return
+	}
+	return c.PacketConn.WriteTo(packet, c.remoteAddr)
+}
+
+func (c *fakeConn) RemoteAddr() net.Addr {
+	return c.remoteAddr
+}
+
+func (c *fakeConn) Close() error {
+	err := c.PacketConn.Close()
+	pool.BufPool.Put(c.bufRef[:cap(c.bufRef)])
+	return err
+}

tunnel/connection.go

@@ -17,6 +17,9 @@ func (t *Tunnel) handleHTTP(request *adapters.HTTPAdapter, outbound net.Conn) {
 	req := request.R
 	host := req.Host
 
+	inboundReeder := bufio.NewReader(request)
+	outboundReeder := bufio.NewReader(conn)
+
 	for {
 		keepAlive := strings.TrimSpace(strings.ToLower(req.Header.Get("Proxy-Connection"))) == "keep-alive"
 
@@ -27,13 +30,23 @@ func (t *Tunnel) handleHTTP(request *adapters.HTTPAdapter, outbound net.Conn) {
 		if err != nil {
 			break
 		}
-		br := bufio.NewReader(conn)
-		resp, err := http.ReadResponse(br, req)
+
+	handleResponse:
+		resp, err := http.ReadResponse(outboundReeder, req)
 		if err != nil {
 			break
 		}
 		adapters.RemoveHopByHopHeaders(resp.Header)
-		if resp.ContentLength >= 0 {
+
+		if resp.StatusCode == http.StatusContinue {
+			err = resp.Write(request)
+			if err != nil {
+				break
+			}
+			goto handleResponse
+		}
+
+		if keepAlive || resp.ContentLength >= 0 {
 			resp.Header.Set("Proxy-Connection", "keep-alive")
 			resp.Header.Set("Connection", "keep-alive")
 			resp.Header.Set("Keep-Alive", "timeout=4")
@@ -46,11 +59,7 @@ func (t *Tunnel) handleHTTP(request *adapters.HTTPAdapter, outbound net.Conn) {
 			break
 		}
 
-		if !keepAlive {
-			break
-		}
-
-		req, err = http.ReadRequest(bufio.NewReader(request))
+		req, err = http.ReadRequest(inboundReeder)
 		if err != nil {
 			break
 		}
@@ -63,54 +72,46 @@ func (t *Tunnel) handleHTTP(request *adapters.HTTPAdapter, outbound net.Conn) {
 	}
 }
 
+func (t *Tunnel) handleUDPToRemote(conn net.Conn, pc net.PacketConn, addr net.Addr) {
+	buf := pool.BufPool.Get().([]byte)
+	defer pool.BufPool.Put(buf[:cap(buf)])
+
+	n, err := conn.Read(buf)
+	if err != nil {
+		return
+	}
+	if _, err = pc.WriteTo(buf[:n], addr); err != nil {
+		return
+	}
+	t.traffic.Up() <- int64(n)
+}
+
+func (t *Tunnel) handleUDPToLocal(conn net.Conn, pc net.PacketConn, key string, timeout time.Duration) {
+	buf := pool.BufPool.Get().([]byte)
+	defer pool.BufPool.Put(buf[:cap(buf)])
+	defer t.natTable.Delete(key)
+	defer pc.Close()
+
+	for {
+		pc.SetReadDeadline(time.Now().Add(timeout))
+		n, _, err := pc.ReadFrom(buf)
+		if err != nil {
+			return
+		}
+
+		n, err = conn.Write(buf[:n])
+		if err != nil {
+			return
+		}
+		t.traffic.Down() <- int64(n)
+	}
+}
+
 func (t *Tunnel) handleSocket(request *adapters.SocketAdapter, outbound net.Conn) {
 	conn := newTrafficTrack(outbound, t.traffic)
 	relay(request, conn)
 }
 
-func (t *Tunnel) handleUDPOverTCP(conn net.Conn, pc net.PacketConn, addr net.Addr) error {
-	ch := make(chan error, 1)
-
-	go func() {
-		buf := pool.BufPool.Get().([]byte)
-		defer pool.BufPool.Put(buf)
-		for {
-			n, err := conn.Read(buf)
-			if err != nil {
-				ch <- err
-				return
-			}
-			pc.SetReadDeadline(time.Now().Add(120 * time.Second))
-			if _, err = pc.WriteTo(buf[:n], addr); err != nil {
-				ch <- err
-				return
-			}
-			t.traffic.Up() <- int64(n)
-			ch <- nil
-		}
-	}()
-
-	buf := pool.BufPool.Get().([]byte)
-	defer pool.BufPool.Put(buf)
-
-	for {
-		pc.SetReadDeadline(time.Now().Add(120 * time.Second))
-		n, _, err := pc.ReadFrom(buf)
-		if err != nil {
-			break
-		}
-
-		if _, err := conn.Write(buf[:n]); err != nil {
-			break
-		}
-
-		t.traffic.Down() <- int64(n)
-	}
-
-	<-ch
-	return nil
-}
-
 // relay copies between left and right bidirectionally.
 func relay(leftConn, rightConn net.Conn) {
 	ch := make(chan error)

tunnel/mode.go

@@ -60,6 +60,6 @@ func (m Mode) String() string {
 	case Direct:
 		return "Direct"
 	default:
-		return "Unknow"
+		return "Unknown"
 	}
 }

tunnel/tunnel.go

@@ -7,6 +7,7 @@ import (
 	"time"
 
 	InboundAdapter "github.com/Dreamacro/clash/adapters/inbound"
+	"github.com/Dreamacro/clash/component/nat"
 	C "github.com/Dreamacro/clash/constant"
 	"github.com/Dreamacro/clash/dns"
 	"github.com/Dreamacro/clash/log"
@@ -17,11 +18,16 @@ import (
 var (
 	tunnel *Tunnel
 	once   sync.Once
+
+	// default timeout for UDP session
+	udpTimeout = 60 * time.Second
 )
 
 // Tunnel handle relay inbound proxy and outbound proxy
 type Tunnel struct {
-	queue     *channels.InfiniteChannel
+	tcpQueue  *channels.InfiniteChannel
+	udpQueue  *channels.InfiniteChannel
+	natTable  *nat.Table
 	rules     []C.Rule
 	proxies   map[string]C.Proxy
 	configMux *sync.RWMutex
@@ -36,7 +42,12 @@ type Tunnel struct {
 
 // Add request to queue
 func (t *Tunnel) Add(req C.ServerAdapter) {
-	t.queue.In() <- req
+	switch req.Metadata().NetWork {
+	case C.TCP:
+		t.tcpQueue.In() <- req
+	case C.UDP:
+		t.udpQueue.In() <- req
+	}
 }
 
 // Traffic return traffic of all connections
@@ -86,11 +97,18 @@ func (t *Tunnel) SetMode(mode Mode) {
 }
 
 func (t *Tunnel) process() {
-	queue := t.queue.Out()
-	for {
-		elm := <-queue
+	go func() {
+		queue := t.udpQueue.Out()
+		for elm := range queue {
+			conn := elm.(C.ServerAdapter)
+			t.handleUDPConn(conn)
+		}
+	}()
+
+	queue := t.tcpQueue.Out()
+	for elm := range queue {
 		conn := elm.(C.ServerAdapter)
-		go t.handleConn(conn)
+		go t.handleTCPConn(conn)
 	}
 }
 
@@ -102,15 +120,7 @@ func (t *Tunnel) needLookupIP(metadata *C.Metadata) bool {
 	return dns.DefaultResolver != nil && (dns.DefaultResolver.IsMapping() || dns.DefaultResolver.IsFakeIP()) && metadata.Host == "" && metadata.DstIP != nil
 }
 
-func (t *Tunnel) handleConn(localConn C.ServerAdapter) {
-	defer localConn.Close()
-	metadata := localConn.Metadata()
-
-	if !metadata.Valid() {
-		log.Warnln("[Metadata] not valid: %#v", metadata)
-		return
-	}
-
+func (t *Tunnel) resolveMetadata(metadata *C.Metadata) (C.Proxy, C.Rule, error) {
 	// preprocess enhanced-mode metadata
 	if t.needLookupIP(metadata) {
 		host, exist := dns.DefaultResolver.IPToHost(*metadata.DstIP)
@@ -124,6 +134,7 @@ func (t *Tunnel) handleConn(localConn C.ServerAdapter) {
 	}
 
 	var proxy C.Proxy
+	var rule C.Rule
 	switch t.mode {
 	case Direct:
 		proxy = t.proxies["DIRECT"]
@@ -132,36 +143,107 @@ func (t *Tunnel) handleConn(localConn C.ServerAdapter) {
 	// Rule
 	default:
 		var err error
-		proxy, err = t.match(metadata)
+		proxy, rule, err = t.match(metadata)
 		if err != nil {
-			return
+			return nil, nil, err
 		}
 	}
+	return proxy, rule, nil
+}
 
-	if metadata.NetWork == C.UDP {
-		pc, addr, err := proxy.DialUDP(metadata)
-		if err != nil {
-			log.Warnln("Proxy[%s] connect [%s --> %s] error: %s", proxy.Name(), metadata.SrcIP.String(), metadata.String(), err.Error())
-			return
-		}
-		defer pc.Close()
-
-		t.handleUDPOverTCP(localConn, pc, addr)
+func (t *Tunnel) handleUDPConn(localConn C.ServerAdapter) {
+	metadata := localConn.Metadata()
+	if !metadata.Valid() {
+		log.Warnln("[Metadata] not valid: %#v", metadata)
 		return
 	}
 
-	remoConn, err := proxy.Dial(metadata)
+	src := localConn.RemoteAddr().String()
+	dst := metadata.RemoteAddress()
+	key := src + "-" + dst
+
+	pc, addr := t.natTable.Get(key)
+	if pc != nil {
+		t.handleUDPToRemote(localConn, pc, addr)
+		return
+	}
+
+	lockKey := key + "-lock"
+	wg, loaded := t.natTable.GetOrCreateLock(lockKey)
+	go func() {
+		if !loaded {
+			wg.Add(1)
+			proxy, rule, err := t.resolveMetadata(metadata)
+			if err != nil {
+				log.Warnln("Parse metadata failed: %s", err.Error())
+				t.natTable.Delete(lockKey)
+				wg.Done()
+				return
+			}
+
+			rawPc, nAddr, err := proxy.DialUDP(metadata)
+			if err != nil {
+				log.Warnln("dial %s error: %s", proxy.Name(), err.Error())
+				t.natTable.Delete(lockKey)
+				wg.Done()
+				return
+			}
+			pc = rawPc
+			addr = nAddr
+
+			if rule != nil {
+				log.Infoln("%s --> %v match %s using %s", metadata.SrcIP.String(), metadata.String(), rule.RuleType().String(), rawPc.Chains().String())
+			} else {
+				log.Infoln("%s --> %v doesn't match any rule using DIRECT", metadata.SrcIP.String(), metadata.String())
+			}
+
+			t.natTable.Set(key, pc, addr)
+			t.natTable.Delete(lockKey)
+			wg.Done()
+			go t.handleUDPToLocal(localConn, pc, key, udpTimeout)
+		}
+
+		wg.Wait()
+		pc, addr := t.natTable.Get(key)
+		if pc != nil {
+			t.handleUDPToRemote(localConn, pc, addr)
+		}
+	}()
+}
+
+func (t *Tunnel) handleTCPConn(localConn C.ServerAdapter) {
+	defer localConn.Close()
+
+	metadata := localConn.Metadata()
+	if !metadata.Valid() {
+		log.Warnln("[Metadata] not valid: %#v", metadata)
+		return
+	}
+
+	proxy, rule, err := t.resolveMetadata(metadata)
 	if err != nil {
-		log.Warnln("Proxy[%s] connect [%s --> %s] error: %s", proxy.Name(), metadata.SrcIP.String(), metadata.String(), err.Error())
+		log.Warnln("Parse metadata failed: %v", err)
 		return
 	}
-	defer remoConn.Close()
+
+	remoteConn, err := proxy.Dial(metadata)
+	if err != nil {
+		log.Warnln("dial %s error: %s", proxy.Name(), err.Error())
+		return
+	}
+	defer remoteConn.Close()
+
+	if rule != nil {
+		log.Infoln("%s --> %v match %s using %s", metadata.SrcIP.String(), metadata.String(), rule.RuleType().String(), remoteConn.Chains().String())
+	} else {
+		log.Infoln("%s --> %v doesn't match any rule using DIRECT", metadata.SrcIP.String(), metadata.String())
+	}
 
 	switch adapter := localConn.(type) {
 	case *InboundAdapter.HTTPAdapter:
-		t.handleHTTP(adapter, remoConn)
+		t.handleHTTP(adapter, remoteConn)
 	case *InboundAdapter.SocketAdapter:
-		t.handleSocket(adapter, remoConn)
+		t.handleSocket(adapter, remoteConn)
 	}
 }
 
@@ -169,17 +251,24 @@ func (t *Tunnel) shouldResolveIP(rule C.Rule, metadata *C.Metadata) bool {
 	return (rule.RuleType() == C.GEOIP || rule.RuleType() == C.IPCIDR) && metadata.Host != "" && metadata.DstIP == nil
 }
 
-func (t *Tunnel) match(metadata *C.Metadata) (C.Proxy, error) {
+func (t *Tunnel) match(metadata *C.Metadata) (C.Proxy, C.Rule, error) {
 	t.configMux.RLock()
 	defer t.configMux.RUnlock()
 
 	var resolved bool
+
+	if node := dns.DefaultHosts.Search(metadata.Host); node != nil {
+		ip := node.Data.(net.IP)
+		metadata.DstIP = &ip
+		resolved = true
+	}
+
 	for _, rule := range t.rules {
 		if !resolved && t.shouldResolveIP(rule, metadata) {
 			ip, err := t.resolveIP(metadata.Host)
 			if err != nil {
 				if !t.ignoreResolveFail {
-					return nil, fmt.Errorf("[DNS] resolve %s error: %s", metadata.Host, err.Error())
+					return nil, nil, fmt.Errorf("[DNS] resolve %s error: %s", metadata.Host, err.Error())
 				}
 				log.Debugln("[DNS] resolve %s error: %s", metadata.Host, err.Error())
 			} else {
@@ -196,20 +285,20 @@ func (t *Tunnel) match(metadata *C.Metadata) (C.Proxy, error) {
 			}
 
 			if metadata.NetWork == C.UDP && !adapter.SupportUDP() {
+				log.Debugln("%v UDP is not supported", adapter.Name())
 				continue
 			}
-
-			log.Infoln("%s --> %v match %s using %s", metadata.SrcIP.String(), metadata.String(), rule.RuleType().String(), rule.Adapter())
-			return adapter, nil
+			return adapter, rule, nil
 		}
 	}
-	log.Infoln("%s --> %v doesn't match any rule using DIRECT", metadata.SrcIP.String(), metadata.String())
-	return t.proxies["DIRECT"], nil
+	return t.proxies["DIRECT"], nil, nil
 }
 
 func newTunnel() *Tunnel {
 	return &Tunnel{
-		queue:     channels.NewInfiniteChannel(),
+		tcpQueue:  channels.NewInfiniteChannel(),
+		udpQueue:  channels.NewInfiniteChannel(),
+		natTable:  nat.New(),
 		proxies:   make(map[string]C.Proxy),
 		configMux: &sync.RWMutex{},
 		traffic:   C.NewTraffic(time.Second),