intial import

backend.go

@@ -0,0 +1,68 @@
+package main
+
+import (
+	"fmt"
+	"net"
+	"net/http"
+	"strings"
+)
+
+// check if net.ParseIP returns nil!!
+func getIP(r *http.Request) net.IP {
+	addr := r.URL.Query().Get("myip")
+	if len(addr) > 0 {
+		return net.ParseIP(addr)
+	}
+
+	addr = r.Header.Get(http.CanonicalHeaderKey("X-Forwarded-For"))
+	if len(addr) > 0 {
+		end := strings.Index(addr, ", ")
+		if end == -1 {
+			end = len(addr)
+		}
+		return net.ParseIP(addr[:end])
+	}
+
+	addr = r.Header.Get(http.CanonicalHeaderKey("X-Real-IP"))
+	if len(addr) > 0 {
+		return net.ParseIP(addr)
+	}
+
+	addr, _, err := net.SplitHostPort(r.RemoteAddr)
+	if err != nil {
+		panic(err)
+	}
+	return net.ParseIP(addr)
+}
+
+func handleRequest(w http.ResponseWriter, r *http.Request, data userData) {
+	msg := "good"
+	defer func() {
+		w.Write([]byte(msg))
+	}()
+
+	hostname := r.URL.Query().Get("hostname")
+	if len(hostname) <= 0 || hostname != data.hostname {
+		msg = "nohost"
+		return
+	}
+
+	ipaddr := getIP(r)
+	if ipaddr == nil {
+		//TODO:
+		msg = "error"
+		return
+	}
+	msg = "Hostname: " + hostname + " , IP: " + ipaddr.String()
+
+	updated, err := updateNameserver(data, ipaddr)
+	if err != nil {
+		msg = "dnserr"
+		fmt.Println(err)
+		return
+	}
+	if !updated {
+		msg = "nochg"
+		return
+	}
+}