Initial implementation of gdl90_websocket, which uses the new GDL90 w…

test/gdl90_websocket.go

@@ -0,0 +1,164 @@
+package main
+
+import (
+	"encoding/hex"
+	"encoding/json"
+	"flag"
+	"fmt"
+	"golang.org/x/net/websocket"
+	"net"
+	"os"
+	"time"
+)
+
+const (
+	configLocation = "./gdl90_websocket.conf"
+)
+
+type dumpdata struct {
+	data string
+}
+
+type HostsType struct {
+	Address string
+	Port    int
+}
+
+type settings struct {
+	Source string
+	//Hosts   []HostsType
+	Host string
+	Port int
+}
+
+var globalSettings settings
+var Verbose bool
+
+func defaultSettings(confFile string) {
+	globalSettings.Source = "192.168.0.1"
+	/*
+		    globalSettings.Hosts = []HostsType{
+				{ Address: "192.168.0.1", Port: 4000 },
+			}
+	*/
+	globalSettings.Host = "192.168.0.1"
+	globalSettings.Port = 4000
+	saveSettings(confFile)
+}
+
+func readSettings(confFile string) {
+	fd, err := os.Open(confFile)
+	if err != nil {
+		fmt.Printf("can't read settings %s: %s\n", confFile, err.Error())
+		defaultSettings(confFile)
+		return
+	}
+	defer fd.Close()
+	buf := make([]byte, 1024)
+	count, err := fd.Read(buf)
+	if err != nil {
+		fmt.Printf("can't read settings %s: %s\n", confFile, err.Error())
+		defaultSettings(confFile)
+		return
+	}
+	var newSettings settings
+	err = json.Unmarshal(buf[0:count], &newSettings)
+	if err != nil {
+		fmt.Printf("can't read settings %s: %s\n", confFile, err.Error())
+		defaultSettings(confFile)
+		return
+	}
+	globalSettings = newSettings
+	fmt.Printf("read in settings.\n")
+}
+
+func saveSettings(confFile string) {
+	fd, err := os.OpenFile(configLocation, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, os.FileMode(0644))
+	if err != nil {
+		err_ret := fmt.Errorf("can't save settings %s: %s", configLocation, err.Error())
+		fmt.Printf("%s\n", err_ret.Error())
+		return
+	}
+	defer fd.Close()
+	jsonSettings, _ := json.Marshal(&globalSettings)
+	fd.Write(jsonSettings)
+	fmt.Printf("wrote settings.\n")
+}
+
+func Usage() {
+    fmt.Printf(`Usage:
+The configuration file contains the source and destination IP and port. Edit
+the configuration file directly to modify the source and destination hosts
+
+    `)
+}
+
+func main() {
+	confFile := flag.String("config", configLocation, "Specify custom config file")
+	Verb := flag.Bool("verbose", false, "Set verbose - show received messages")
+    HelpFlag := flag.Bool("info", false, "Show detailed help")
+	flag.Parse()
+	Verbose = *Verb
+    if *HelpFlag {
+        Usage()
+        os.Exit(0)
+    }
+	readSettings(*confFile)
+	initWebsocketClient(globalSettings.Source)
+}
+
+func initWebsocketClient(srcHost string) {
+
+	fmt.Printf("Starting Client, trying to connect to %s\n", srcHost)
+	ws, err := websocket.Dial(fmt.Sprintf("ws://%s/gdl90", srcHost), "", fmt.Sprintf("http://%s/gdl90", srcHost))
+	if err != nil {
+		fmt.Printf("Dial failed: %s\n", err.Error())
+		os.Exit(1)
+	}
+
+	fmt.Printf("Connected to %s\n", srcHost)
+
+	dest := fmt.Sprintf("%s:%d", globalSettings.Host, globalSettings.Port)
+	fmt.Printf("Destination %s\n", dest)
+	udp, err := net.Dial("udp", dest)
+	if err != nil {
+		fmt.Printf("Dial failed: %s\n", err.Error())
+	}
+
+	incomingMessages := make(chan string)
+	go readClientMessages(ws, incomingMessages)
+	i := 0
+	for {
+		select {
+		case <-time.After(time.Duration(2e9)):
+			i++
+		case message := <-incomingMessages:
+			var d []byte
+			err := json.Unmarshal([]byte(message), &d)
+			if err != nil {
+				fmt.Printf("json.Unmarshal(): %s\n", err.Error())
+				continue
+			}
+			if Verbose {
+				fmt.Printf(hex.Dump(d))
+			}
+			_, err2 := udp.Write(d)
+			if err2 != nil {
+				fmt.Printf("Write failed: %s\n", err2.Error())
+			}
+		}
+	}
+}
+
+func readClientMessages(ws *websocket.Conn, incomingMessages chan string) {
+	for {
+		var message string
+		// err := websocket.JSON.Receive(ws, &message)
+		err := websocket.Message.Receive(ws, &message)
+		if err != nil {
+			fmt.Printf("Error::: %s\n", err.Error())
+			return
+		}
+		incomingMessages <- message
+	}
+}