added another way to configure arpspoofer, added some funcs to network

Author: shadowy-pycoder

arpspoof/arpspoof.go

@@ -23,7 +23,6 @@ import (
 )
 
 const (
-	protocolARP = 0x0806
 	unixEthPAll = 0x03
 )
 
@@ -32,6 +31,9 @@ var (
 	probeTargetsInterval    = 60 * time.Second
 	refreshARPTableInterval = 15 * time.Second
 	arpSpoofTargetsInterval = 1 * time.Second
+	errARPSpoofConfig       = fmt.Errorf(
+		`failed parsing arp options. Example: "targets 10.0.0.1,10.0.0.5-10,192.168.1.*,192.168.10.0/24;fullduplex false;debug true"`,
+	)
 )
 
 type Packet struct {
@@ -48,6 +50,45 @@ type ARPSpoofConfig struct {
 	Debug      bool
 }
 
+// NewARPSpoofConfig creates ARPSpoofConfig from a list of options separated by semicolon and logger.
+//
+// Example: "targets 10.0.0.1,10.0.0.5-10,192.168.1.*,192.168.10.0/24;fullduplex false;debug true;interface eth0;gateway 192.168.1.1"`.
+// All fields in configuration string are optional.
+func NewARPSpoofConfig(s string, logger *zerolog.Logger) (*ARPSpoofConfig, error) {
+	asc := &ARPSpoofConfig{Logger: logger}
+	for opt := range strings.SplitSeq(strings.ToLower(s), ";") {
+		keyval := strings.SplitN(strings.Trim(opt, " "), " ", 2)
+		if len(keyval) < 2 {
+			return nil, errARPSpoofConfig
+		}
+		key := keyval[0]
+		val := keyval[1]
+		switch key {
+		case "targets":
+			asc.Targets = val
+		case "interface":
+			asc.Interface = val
+		case "gateway":
+			gateway, err := netip.ParseAddr(val)
+			if err != nil {
+				return nil, err
+			}
+			asc.Gateway = &gateway
+		case "fullduplex":
+			if val == "true" {
+				asc.FullDuplex = true
+			}
+		case "debug":
+			if val == "true" {
+				asc.Debug = true
+			}
+		default:
+			return nil, errARPSpoofConfig
+		}
+	}
+	return asc, nil
+}
+
 type ARPTable struct {
 	sync.RWMutex
 	Ifname  string

cmd/marpspoof/main.go

@@ -38,7 +38,7 @@ func root(args []string) error {
 	flags.BoolVar(&conf.Debug, "d", false, "Enable debug logging")
 	nocolor := flags.Bool("nocolor", false, "Disable colored output")
 	flags.BoolFunc("I", "Display list of interfaces and exit.", func(flagValue string) error {
-		if err := network.DisplayInterfaces(); err != nil {
+		if err := network.DisplayInterfaces(false); err != nil {
 			fmt.Fprintf(os.Stderr, "%s: %v\n", app, err)
 			os.Exit(2)
 		}

cmd/mshark/cli.go

@@ -89,7 +89,7 @@ func root(args []string) error {
 	packetBuffer := flags.Int("b", 8192, "The maximum size of packet queue.")
 	flags.StringVar(&conf.Expr, "e", "", `BPF filter expression. Example: "ip proto tcp".`)
 	flags.BoolFunc("D", "Display list of interfaces and exit.", func(flagValue string) error {
-		if err := network.DisplayInterfaces(); err != nil {
+		if err := network.DisplayInterfaces(true); err != nil {
 			fmt.Fprintf(os.Stderr, "%s: %v\n", app, err)
 			os.Exit(2)
 		}

network/network.go

@@ -42,15 +42,17 @@ func InterfaceByName(name string) (*net.Interface, error) {
 	return in, nil
 }
 
-func DisplayInterfaces() error {
+func DisplayInterfaces(includeAny bool) error {
 	w := new(tabwriter.Writer)
 	w.Init(os.Stdout, 0, 0, 2, ' ', tabwriter.TabIndent)
 	ifaces, err := net.Interfaces()
 	if err != nil {
 		return fmt.Errorf("failed to get network interfaces: %v", err)
 	}
 	fmt.Fprintln(w, "Index\tName\tFlags")
-	fmt.Fprintln(w, "0\tany\tUP")
+	if includeAny {
+		fmt.Fprintln(w, "0\tany\tUP")
+	}
 	for _, iface := range ifaces {
 		fmt.Fprintf(w, "%d\t%s\t%s\n", iface.Index, iface.Name, strings.ToUpper(iface.Flags.String()))
 	}
@@ -146,3 +148,16 @@ func GetIPv4PrefixFromInterface(iface *net.Interface) (netip.Prefix, error) {
 	}
 	return netip.Prefix{}, fmt.Errorf("no IPv4 prefix found")
 }
+
+func IsLocalAddress(addr string) bool {
+	host, _, err := net.SplitHostPort(addr)
+	if err != nil {
+		host = addr
+	}
+	ip := net.ParseIP(host)
+	if ip != nil {
+		return ip.IsLoopback()
+	}
+	host = strings.ToLower(host)
+	return strings.HasSuffix(host, ".local") || host == "localhost"
+}

version.go

@@ -1,3 +1,3 @@
 package mshark
 
-const Version string = "mshark v0.0.9"
+const Version string = "mshark v0.0.10"