Multi-server support in local: randomly select one server.

cmd/shadowsocks-local/local.go

@@ -8,6 +8,7 @@ import (
 	ss "github.com/shadowsocks/shadowsocks-go/shadowsocks"
 	"io"
 	"log"
+	"math/rand"
 	"net"
 	"os"
 	"path"
@@ -159,7 +160,7 @@ func handleConnection(conn net.Conn, server string, encTbl *ss.EncryptTable) {
 		return
 	}
 
-	debug.Println("connecting to", addr)
+	debug.Printf("connecting to %s via %s\n", addr, server)
 	remote, err := ss.DialWithRawAddr(rawaddr, server, encTbl)
 	if err != nil {
 		log.Println("error connect to shadowsocks server:", err)
@@ -174,7 +175,14 @@ func handleConnection(conn net.Conn, server string, encTbl *ss.EncryptTable) {
 	debug.Println("closing")
 }
 
-func run(port, password, server string) {
+func getServer(server []string) string {
+	if len(server) == 0 {
+		return server[0]
+	}
+	return server[rand.Intn(len(server))]
+}
+
+func run(port, password string, server []string) {
 	ln, err := net.Listen("tcp", ":"+port)
 	if err != nil {
 		log.Fatal(err)
@@ -187,27 +195,28 @@ func run(port, password, server string) {
 			log.Println("accept:", err)
 			continue
 		}
-		go handleConnection(conn, server, encTbl)
+		go handleConnection(conn, getServer(server), encTbl)
 	}
 }
 
 func enoughOptions(config *ss.Config) bool {
-	return config.Server != "" && config.ServerPort != 0 &&
+	return config.Server != nil && config.ServerPort != 0 &&
 		config.LocalPort != 0 && config.Password != ""
 }
 
 func main() {
-	var configFile string
+	var configFile, cmdServer string
 	var cmdConfig ss.Config
 
 	flag.StringVar(&configFile, "c", "config.json", "specify config file")
-	flag.StringVar(&cmdConfig.Server, "s", "", "server address")
+	flag.StringVar(&cmdServer, "s", "", "server address")
 	flag.StringVar(&cmdConfig.Password, "k", "", "password")
 	flag.IntVar(&cmdConfig.ServerPort, "p", 0, "server port")
 	flag.IntVar(&cmdConfig.LocalPort, "l", 0, "local socks5 proxy port")
 	flag.BoolVar((*bool)(&debug), "d", false, "print debug message")
 
 	flag.Parse()
+	cmdConfig.Server = cmdServer
 
 	exists, err := ss.IsFileExists(configFile)
 	// If no config file in current directory, try search it in the binary directory
@@ -223,20 +232,25 @@ func main() {
 	if err != nil {
 		config = &cmdConfig
 		if os.IsNotExist(err) {
-			if !enoughOptions(config) {
-				log.Println("must specify server address, password and both server/local port")
-				os.Exit(1)
-			}
-			log.Println("using all options from command line")
+			log.Println("config file not found, using all options from command line")
 		} else {
 			log.Printf("error reading config file: %v\n", err)
 			os.Exit(1)
 		}
 	} else {
 		ss.UpdateConfig(config, &cmdConfig)
 	}
+	if !enoughOptions(config) {
+		log.Println("must specify server address, password and both server/local port")
+		os.Exit(1)
+	}
 	ss.SetDebug(debug)
 
-	run(strconv.Itoa(config.LocalPort), config.Password,
-		config.Server+":"+strconv.Itoa(config.ServerPort))
+	srvArr := config.GetServerArray()
+	srvPort := strconv.Itoa(config.ServerPort)
+	for i, _ := range srvArr {
+		srvArr[i] += ":" + srvPort
+	}
+
+	run(strconv.Itoa(config.LocalPort), config.Password, srvArr)
 }

cmd/shadowsocks-server/server.go

@@ -368,7 +368,7 @@ func main() {
 	config, err = ss.ParseConfig(configFile)
 	if err != nil {
 		if os.IsNotExist(err) {
-			log.Println("using all options from command line")
+			log.Println("config file not found, using all options from command line")
 		} else {
 			log.Printf("error reading %s: %v\n", configFile, err)
 			os.Exit(1)

config.json

@@ -1,5 +1,5 @@
 {
-    "server":"127.0.0.1",
+    "server":["127.0.0.1"],
     "server_port":8388,
     "local_port":1080,
     "password":"barfoo!",

shadowsocks/config.go

@@ -9,14 +9,15 @@ package shadowsocks
 
 import (
 	"encoding/json"
+	"fmt"
 	"io/ioutil"
 	"os"
 	"reflect"
 	"time"
 )
 
 type Config struct {
-	Server        string            `json:"server"`
+	Server        interface{}       `json:"server"`
 	ServerPort    int               `json:"server_port"`
 	LocalPort     int               `json:"local_port"`
 	Password      string            `json:"password"`
@@ -27,6 +28,29 @@ type Config struct {
 
 var readTimeout time.Duration
 
+func (config *Config) GetServerArray() []string {
+	if config.Server == nil {
+		return nil
+	}
+	single, ok := config.Server.(string)
+	if ok {
+		return []string{single}
+	}
+	arr, ok := config.Server.([]interface{})
+	if ok {
+		serverArr := make([]string, len(arr), len(arr))
+		for i, s := range arr {
+			serverArr[i], ok = s.(string)
+			if !ok {
+				goto typeError
+			}
+		}
+		return serverArr
+	}
+typeError:
+	panic(fmt.Sprintf("Config.Server type error %v", reflect.TypeOf(config.Server)))
+}
+
 func ParseConfig(path string) (config *Config, err error) {
 	file, err := os.Open(path) // For read access.
 	if err != nil {

shadowsocks/config_test.go

@@ -19,6 +19,10 @@ func TestParseConfig1Password(t *testing.T) {
 	if !config.CacheEncTable {
 		t.Error("cache_enctable should be true")
 	}
+	srvArr := config.GetServerArray()
+	if len(srvArr) != 1 || srvArr[0] != "127.0.0.1" {
+		t.Error("server option is not set correctly")
+	}
 }
 
 func TestParseConfigMultiPassword(t *testing.T) {
@@ -33,4 +37,28 @@ func TestParseConfigMultiPassword(t *testing.T) {
 	if config.PortPassword["8387"] != "foobar" {
 		t.Error("wrong multiple password for port 8387")
 	}
+
+	srvArr := config.GetServerArray()
+	if len(srvArr) != 2 {
+		t.Error("server option is not set correctly")
+	}
+	if srvArr[0] != "127.0.0.1" {
+		t.Error("1st server wrong")
+	}
+	if srvArr[1] != "127.0.1.1" {
+		t.Error("2nd server wrong")
+	}
+}
+
+func TestParseConfigEmpty(t *testing.T) {
+	// make sure we will not crash
+	config, err := ParseConfig("testdata/noserver.json")
+	if err != nil {
+		t.Error("error parsing noserver config:", err)
+	}
+
+	srvArr := config.GetServerArray()
+	if srvArr != nil {
+		t.Error("GetServerArray should return nil if no server option is given")
+	}
 }

shadowsocks/testdata/config-multi-passwd.json

@@ -1,5 +1,5 @@
 {
-    "server":"127.0.0.1",
+    "server":["127.0.0.1", "127.0.1.1"],
     "server_port":8388,
     "local_port":1081,
     "password":"barfoo!",

shadowsocks/testdata/noserver.json

@@ -0,0 +1,7 @@
+{
+    "server_port":8388,
+    "local_port":1081,
+    "password":"barfoo!",
+    "timeout":60,
+    "cache_enctable": true
+}