Start writing socket server in Go

.gitignore

@@ -3,5 +3,8 @@ npm-debug.log
 build
 Extension Building
 .idea
+*.iml
 script.js
 script.min.js
+
+/socketserver/cmd/socketserver/socketserver

socketserver/cmd/socketserver/socketserver.go

@@ -0,0 +1,48 @@
+package main // import "bitbucket.org/stendec/frankerfacez/socketserver/cmd/socketserver"
+
+import (
+	"flag"
+	"../../lib"
+	"log"
+	"net/http"
+)
+
+var origin *string = flag.String("origin", "localhost:8001", "Client-visible origin of the socket server")
+var bindAddress *string = flag.String("listen", "", "Address to bind to, if different from origin")
+var certificateFile *string = flag.String("crt", "", "SSL certificate file")
+var privateKeyFile *string = flag.String("key", "", "SSL private key file")
+
+func main() {
+	flag.Parse()
+
+	if *origin == "" {
+		log.Fatalln("--origin argument required")
+	}
+	if *bindAddress == "" {
+		bindAddress = origin
+	}
+	if (*certificateFile == "") != (*privateKeyFile == "") {
+		log.Fatalln("Either both --crt and --key can be provided, or neither.")
+	}
+
+	conf := &lib.Config {
+		SSLKeyFile: *privateKeyFile,
+		SSLCertificateFile: *certificateFile,
+		UseSSL: *certificateFile != "",
+
+		Origin: *origin,
+	}
+
+	lib.SetupServerAndHandle(conf)
+
+	var err error
+	if conf.UseSSL {
+		err = http.ListenAndServeTLS(*bindAddress, *certificateFile, *privateKeyFile, nil)
+	} else {
+		err = http.ListenAndServe(*bindAddress, nil)
+	}
+
+	if err != nil {
+		log.Fatal("ListenAndServe: ", err)
+	}
+}

socketserver/lib/handlecore.go

@@ -0,0 +1,237 @@
+package lib // import "bitbucket.org/stendec/frankerfacez/socketserver/lib"
+
+import (
+	"net/http"
+	"golang.org/x/net/websocket"
+	"crypto/tls"
+	"log"
+	"strings"
+	"strconv"
+	"errors"
+	"encoding/json"
+	"fmt"
+)
+
+const MAX_PACKET_SIZE = 1024
+
+type Config struct {
+	SSLCertificateFile string
+	SSLKeyFile         string
+	UseSSL             bool
+
+	Origin             string
+}
+
+// A command is how the client refers to a function on the server. It's just a string.
+type Command string
+
+type ClientMessage struct {
+	MessageID int
+    // The command that the client wants from the server.
+    // When sent from the server, the literal string 'True' indicates success.
+	// Before sending, a blank Command will be converted into SuccessCommand.
+	Command   Command
+	Arguments interface{}
+}
+
+// Sent by the server in ClientMessage.Command to indicate success.
+const SuccessCommand Command = "True"
+
+var FFZCodec websocket.Codec = websocket.Codec{
+	Marshal: MarshalClientMessage,
+	Unmarshal: UnmarshalClientMessage,
+}
+
+// Errors that get returned to the client.
+var ProtocolError error = errors.New("FFZ Socket protocol error.")
+var ExpectedSingleString = errors.New("Error: Expected single string as arguments.")
+var ExpectedTwoStrings = errors.New("Error: Expected array of string, string as arguments.")
+var ExpectedStringAndInt = errors.New("Error: Expected array of string, int as arguments.")
+var ExpectedStringAndIntGotFloat = errors.New("Error: Second argument was a float, expected an integer.")
+
+func SetupServer(config *Config) *websocket.Server {
+	sockConf, err := websocket.NewConfig("/", config.Origin)
+	if err != nil {
+		panic(err)
+	}
+	if config.UseSSL {
+		cert, err := tls.LoadX509KeyPair(config.SSLCertificateFile, config.SSLKeyFile)
+		if err != nil {
+			panic(err)
+		}
+		tlsConf := &tls.Config{
+			Certificates: []tls.Certificate{cert},
+			ServerName: config.Origin,
+		}
+		tlsConf.BuildNameToCertificate()
+		sockConf.TlsConfig = tlsConf
+	}
+
+	sockServer := &websocket.Server{}
+	sockServer.Config = *sockConf
+	sockServer.Handler = HandleSocketConnection
+	return sockServer
+}
+
+// Set up a websocket listener and register it on /.
+// (Uses http.DefaultServeMux .)
+func SetupServerAndHandle(config *Config) {
+	sockServer := SetupServer(config)
+
+	http.HandleFunc("/", sockServer.ServeHTTP)
+}
+
+// Handle a new websocket connection from a FFZ client.
+// This runs in a goroutine started by net/http.
+func HandleSocketConnection(conn *websocket.Conn) {
+	// websocket.Conn is a ReadWriteCloser
+	var msg ClientMessage
+	var err error = nil
+	var abort bool
+
+	log.Print("Got a connection from ", conn.RemoteAddr())
+
+	for ; err == nil || abort; err = FFZCodec.Receive(conn, &msg) {
+		log.Print(msg)
+	}
+
+	if err != nil {
+		FFZCodec.Send(conn, ClientMessage{
+			MessageID: -1,
+			Command: "error",
+			Arguments: err.Error(),
+		})
+	}
+	conn.Close()
+}
+
+// Unpack a message sent from the client into a ClientMessage.
+func UnmarshalClientMessage(data []byte, payloadType byte, v interface{}) (err error) {
+	var spaceIdx int
+
+	out := v.(*ClientMessage)
+	dataStr := string(data)
+
+	// Message ID
+	spaceIdx = strings.IndexRune(dataStr, ' ')
+	if spaceIdx == -1 {
+		return ProtocolError
+	}
+	messageId, err := strconv.Atoi(dataStr[:spaceIdx])
+	if messageId <= 0 {
+		return ProtocolError
+	}
+
+	out.MessageID = messageId
+	dataStr = dataStr[spaceIdx + 1:]
+
+	spaceIdx = strings.IndexRune(dataStr, ' ')
+	if spaceIdx == -1 {
+		out.Command = Command(dataStr)
+		out.Arguments = nil
+		return nil
+	} else {
+		out.Command = Command(dataStr[:spaceIdx])
+	}
+	dataStr = dataStr[spaceIdx + 1:]
+	argumentsJson := dataStr
+	err = json.Unmarshal([]byte(argumentsJson), &out.Arguments)
+	if err != nil {
+		return
+	}
+	return nil
+}
+
+func MarshalClientMessage(clientMessage interface{}) (data []byte, payloadType byte, err error) {
+	var msg ClientMessage
+	var ok bool
+	msg, ok = clientMessage.(ClientMessage)
+	if !ok {
+		pMsg, ok := clientMessage.(*ClientMessage)
+		if !ok {
+			panic("MarshalClientMessage: argument needs to be a ClientMessage")
+		}
+		msg = *pMsg
+	}
+	var dataStr string
+
+	if msg.Command == "" {
+		msg.Command = SuccessCommand
+	}
+
+	if msg.Arguments != nil {
+		argBytes, err := json.Marshal(msg.Arguments)
+		if err != nil {
+			return nil, 0, err
+		}
+
+		dataStr = fmt.Sprintf("%d %s %s", msg.MessageID, msg.Command, string(argBytes))
+	} else {
+		dataStr = fmt.Sprintf("%d %s", msg.MessageID, msg.Command)
+	}
+
+	return []byte(dataStr), websocket.TextFrame, nil
+}
+
+
+// Convenience method: Parse the arguments of the ClientMessage as a single string.
+func (cm *ClientMessage) ArgumentsAsString() (string1 string, err error) {
+	var ok bool
+	string1, ok = cm.Arguments.(string)
+	if !ok {
+		err = ExpectedSingleString; return
+	} else {
+		return string1, nil
+	}
+}
+
+// Convenience method: Parse the arguments of the ClientMessage as an array of two strings.
+func (cm *ClientMessage) ArgumentsAsTwoStrings() (string1, string2 string, err error) {
+	var ok bool
+	var ary []interface{}
+	ary, ok = cm.Arguments.([]interface{})
+	if !ok {
+		err = ExpectedTwoStrings; return
+	} else {
+		if len(ary) != 2 {
+			err = ExpectedTwoStrings; return
+		}
+		string1, ok = ary[0].(string)
+		if !ok {
+			err = ExpectedTwoStrings; return
+		}
+		string2, ok = ary[1].(string)
+		if !ok {
+			err = ExpectedTwoStrings; return
+		}
+		return string1, string2, nil
+	}
+}
+
+// Convenience method: Parse the arguments of the ClientMessage as an array of a string and an int.
+func (cm *ClientMessage) ArgumentsAsStringAndInt() (string1 string, int int64, err error) {
+	var ok bool
+	var ary []interface{}
+	ary, ok = cm.Arguments.([]interface{})
+	if !ok {
+		err = ExpectedStringAndInt; return
+	} else {
+		if len(ary) != 2 {
+			err = ExpectedStringAndInt; return
+		}
+		string1, ok = ary[0].(string)
+		if !ok {
+			err = ExpectedStringAndInt; return
+		}
+		var num float64
+		num, ok = ary[1].(float64)
+		if !ok {
+			err = ExpectedStringAndInt; return
+		}
+		int = int64(num)
+		if float64(int) != num {
+			err = ExpectedStringAndIntGotFloat; return
+		}
+		return string1, int, nil
+	}
+}

socketserver/lib/handlecore_test.go

@@ -0,0 +1,37 @@
+package lib
+
+import (
+	"golang.org/x/net/websocket"
+	"fmt"
+)
+
+func ExampleUnmarshalClientMessage() {
+	sourceData := []byte("100 hello [\"ffz_3.5.30\",\"898b5bfa-b577-47bb-afb4-252c703b67d6\"]")
+	var cm ClientMessage
+	err := UnmarshalClientMessage(sourceData, websocket.TextFrame, &cm)
+	fmt.Println(err)
+	fmt.Println(cm.MessageID)
+	fmt.Println(cm.Command)
+	fmt.Println(cm.Arguments)
+	// Output:
+	// <nil>
+	// 100
+	// hello
+	// [ffz_3.5.30 898b5bfa-b577-47bb-afb4-252c703b67d6]
+}
+
+func ExampleMarshalClientMessage() {
+	var cm ClientMessage = ClientMessage{
+		MessageID: -1,
+		Command: "do_authorize",
+		Arguments: "1234567890",
+	}
+	data, payloadType, err := MarshalClientMessage(&cm)
+	fmt.Println(err)
+	fmt.Println(payloadType == websocket.TextFrame)
+	fmt.Println(string(data))
+	// Output:
+	// <nil>
+	// true
+	// -1 do_authorize "1234567890"
+}

src/socket.js

@@ -40,7 +40,7 @@ FFZ.prototype.ws_create = function() {
 	this._ws_pending = this._ws_pending || [];
 
 	try {
-		ws = this._ws_sock = new WebSocket("ws://" + constants.WS_SERVERs[this._ws_host_idx] + "/");
+		ws = this._ws_sock = new WebSocket("ws://" + constants.WS_SERVERS[this._ws_host_idx] + "/");
 	} catch(err) {
 		this._ws_exists = false;
 		return this.log("Error Creating WebSocket: " + err);