1 files changed, 121 insertions, 0 deletions
diff --git a/src/rhrdtime/rhrdtime.go b/src/rhrdtime/rhrdtime.go
new file mode 100644
index 0000000..4bdf680
--- /dev/null
+++ b/src/rhrdtime/rhrdtime.go
@@ -0,0 +1,121 @@
+//
+//  rhrdtime
+//
+//  The Radio Helsinki Rivendell Time Websocket Server
+//
+//
+//  Copyright (C) 2015 Christian Pointner <equinox@helsinki.at>
+//
+//  This file is part of rhrdtime.
+//
+//  rhrdtime is free software: you can redistribute it and/or modify
+//  it under the terms of the GNU General Public License as published by
+//  the Free Software Foundation, either version 3 of the License, or
+//  any later version.
+//
+//  rhrdtime is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU General Public License for more details.
+//
+//  You should have received a copy of the GNU General Public License
+//  along with rhrdtime. If not, see <http://www.gnu.org/licenses/>.
+//
+
+package main
+
+import (
+	"encoding/json"
+	"flag"
+	"fmt"
+	"net/http"
+	_ "net/http/pprof"
+	"time"
+
+	"github.com/gorilla/websocket"
+)
+
+var (
+	loc *time.Location
+)
+
+func init() {
+	var err error
+	if loc, err = time.LoadLocation("Europe/Vienna"); err != nil {
+		fmt.Println("Error while loading loaction Europe/Vienna:", err)
+	}
+}
+
+func getTZOffset(t time.Time) int {
+	t = t.In(loc)
+	_, offset := t.Zone()
+	return offset
+}
+
+type ntpMessage struct {
+	T1       int64 `json:"t1"`
+	T2       int64 `json:"t2"`
+	T3       int64 `json:"t3"`
+	T4       int64 `json:"t4"`
+	TZOffset int   `json:"tz_offset"`
+}
+
+func handleNTPClient(w http.ResponseWriter, r *http.Request) {
+	ws, err := websocket.Upgrade(w, r, nil, 1024, 1024)
+	if _, ok := err.(websocket.HandshakeError); ok {
+		http.Error(w, "Not a websocket handshake", 400)
+		return
+	} else if err != nil {
+		fmt.Println(err)
+		return
+	}
+	fmt.Println("Client", ws.RemoteAddr(), "connected")
+
+	for {
+		msgtype, msg, err := ws.ReadMessage()
+		if err != nil {
+			fmt.Println("Client", ws.RemoteAddr(), "disconnected:", err)
+			return
+		}
+		now_t2 := time.Now()
+		if msgtype == websocket.TextMessage {
+
+			var n ntpMessage
+			if err := json.Unmarshal(msg, &n); err != nil {
+				fmt.Println("Ignoring malformed (", err, ") NTP message from:", ws.RemoteAddr())
+				continue
+			}
+
+			n.T2 = (now_t2.Unix() * 1000) + int64(now_t2.Nanosecond()/1000000)
+			n.TZOffset = getTZOffset(now_t2)
+
+			now_t3 := time.Now()
+			n.T3 = (now_t3.Unix() * 1000) + int64(now_t3.Nanosecond()/1000000)
+
+			ntp_json, err := json.Marshal(n)
+			if err != nil {
+				fmt.Println("Error while encoding to json:", err)
+				continue
+			}
+			if err := ws.WriteMessage(websocket.TextMessage, ntp_json); err != nil {
+				fmt.Println("Client", ws.RemoteAddr(), "write error:", err)
+				return
+			}
+		}
+	}
+}
+
+func main() {
+	addr_s := flag.String("addr", ":3000", "addr:port to listen on, default: ':3000'")
+	help := flag.Bool("help", false, "show usage")
+
+	flag.Parse()
+	if *help {
+		flag.Usage()
+		return
+	}
+
+	http.HandleFunc("/ntp", handleNTPClient)
+
+	http.ListenAndServe(*addr_s, nil)
+}