yeah i should have done this before, i know

session/modules/net_probe.go

@@ -0,0 +1,138 @@
+package session_modules
+
+import (
+	"fmt"
+	// "github.com/evilsocket/bettercap/packets"
+	"github.com/evilsocket/bettercap/session"
+	"github.com/malfunkt/iprange"
+	"net"
+	"time"
+)
+
+type Prober struct {
+	session.SessionModule
+}
+
+func NewProber(s *session.Session) *Prober {
+	p := &Prober{
+		SessionModule: session.NewSessionModule(s),
+	}
+
+	p.AddParam(session.NewIntParameter("net.probe.throttle", "10", "", "If greater than 0, probe packets will be throttled by this value in milliseconds."))
+
+	p.AddHandler(session.NewModuleHandler("net.probe (on|off)", "^net\\.probe\\s+(on|off)$",
+		"Start/stop network hosts probing in background.",
+		func(args []string) error {
+			if args[0] == "on" {
+				return p.Start()
+			} else {
+				return p.Stop()
+			}
+		}))
+
+	return p
+}
+
+func (p Prober) Name() string {
+	return "Network Prober"
+}
+
+func (p Prober) Description() string {
+	return "Keep probing for new hosts on the network by sending dummy UDP packets to every possible IP on the subnet."
+}
+
+func (p Prober) Author() string {
+	return "Simone Margaritelli <evilsocket@protonmail.com>"
+}
+
+func (p *Prober) shouldProbe(ip net.IP) bool {
+	addr := ip.String()
+	if ip.IsLoopback() == true {
+		return false
+	} else if addr == p.Session.Interface.IpAddress {
+		return false
+	} else if addr == p.Session.Gateway.IpAddress {
+		return false
+	} else if p.Session.Targets.Has(addr) == true {
+		return false
+	}
+	return true
+}
+
+func (p Prober) OnSessionEnded(s *session.Session) {
+	if p.Running() {
+		p.Stop()
+	}
+}
+
+func (p *Prober) sendUDP(from net.IP, from_hw net.HardwareAddr, ip net.IP) {
+	name := fmt.Sprintf("%s:137", ip)
+	if addr, err := net.ResolveUDPAddr("udp", name); err != nil {
+		log.Errorf("Could not resolve %s.", name)
+	} else if con, err := net.DialUDP("udp", nil, addr); err != nil {
+		log.Errorf("Could not dial %s.", name)
+	} else {
+		// log.Debugf("UDP connection to %s enstablished.\n", name)
+		defer con.Close()
+		con.Write([]byte{0xde, 0xad, 0xbe, 0xef})
+	}
+}
+
+func (p *Prober) Start() error {
+	if p.Running() == false {
+		throttle := int(0)
+		if err, v := p.Param("net.probe.throttle").Get(p.Session); err != nil {
+			return err
+		} else {
+			throttle = v.(int)
+			log.Debugf("Throttling packets of %d ms.\n", throttle)
+		}
+
+		p.SetRunning(true)
+
+		go func() {
+			list, err := iprange.Parse(p.Session.Interface.CIDR())
+			if err != nil {
+				log.Fatal(err)
+			}
+
+			from := p.Session.Interface.IP
+			from_hw := p.Session.Interface.HW
+			addresses := list.Expand()
+
+			log.Infof("Network prober started, probing %d possible addresses.\n", len(addresses))
+
+			for p.Running() {
+				for _, ip := range addresses {
+					if p.shouldProbe(ip) == false {
+						log.Debugf("Skipping address %s from UDP probing.\n", ip)
+						continue
+					}
+
+					p.sendUDP(from, from_hw, ip)
+
+					if throttle > 0 {
+						time.Sleep(time.Duration(throttle) * time.Millisecond)
+					}
+				}
+
+				time.Sleep(5 * time.Second)
+			}
+
+			log.Info("Network prober stopped.\n")
+		}()
+
+		return nil
+	} else {
+		return fmt.Errorf("Network prober already started.")
+	}
+}
+
+func (p *Prober) Stop() error {
+	if p.Running() == true {
+		p.SetRunning(false)
+		return nil
+	} else {
+		return fmt.Errorf("Network prober already stopped.")
+	}
+}