add command line arguments

main.go

@@ -1,8 +1,10 @@
 package main
 
 import (
+	"flag"
 	"fmt"
 	"log"
+	"strings"
 
 	"git.freifunk-franken.de/jkimmel/abbel/capture"
 	"git.freifunk-franken.de/jkimmel/abbel/packet"
@@ -11,21 +13,29 @@ import (
 )
 
 type options struct {
-	Group      string
-	Port       uint16
-	Ifs        []string
-	UseCapture bool
+	Group        string
+	Port         uint16
+	Ifs          []string
+	UseMulticast bool
 }
 
 func parseOpts() (options, error) {
 	var opt options
 	var err error
 
-	opt = options{
-		Group:      "ff02:0:0:0:0:0:1:6",
-		Port:       6696,
-		Ifs:        []string{"babel"},
-		UseCapture: false,
+	flag.StringVar(&opt.Group, "group", "ff02:0:0:0:0:0:1:6", "Multicast group to join")
+	port := flag.Uint("port", 6696, "Port to listen on")
+	flag.BoolVar(&opt.UseMulticast, "m", false, "Use multicast mode")
+	ifs := flag.String("i", "any", "Comma-seperated list of interfaces to listen on or \"any\" for all interfaces in capture mode")
+	flag.Parse()
+
+	if *port == 0 || *port >= 0xffff {
+		return options{}, fmt.Errorf("Invalid port %q", *port)
+	}
+	opt.Port = uint16(*port)
+
+	for _, iface := range strings.Split(*ifs, ",") {
+		opt.Ifs = append(opt.Ifs, iface)
 	}
 
 	return opt, err
@@ -50,10 +60,10 @@ func run(opt options) error {
 	var err error
 	var conn BabelPacketConn
 
-	if opt.UseCapture {
-		conn, err = capture.FromInterface(opt.Ifs[0])
-	} else {
+	if opt.UseMulticast {
 		conn, err = packet.Listen(opt.Group, opt.Port, opt.Ifs...)
+	} else {
+		conn, err = capture.FromInterface(opt.Ifs[0])
 	}
 	if err != nil {
 		return err