Refactoring modules

modules/net_sniff/net_sniff_fuzz.go

@@ -0,0 +1,121 @@
+package net_sniff
+
+import (
+	"math/rand"
+	"strings"
+
+	"github.com/google/gopacket"
+
+	"github.com/bettercap/bettercap/log"
+
+	"github.com/evilsocket/islazy/str"
+	"github.com/evilsocket/islazy/tui"
+)
+
+var mutators = []func(byte) byte{
+	func(b byte) byte {
+		return byte(rand.Intn(256) & 0xff)
+	},
+	func(b byte) byte {
+		return byte(b << uint(rand.Intn(9)))
+	},
+	func(b byte) byte {
+		return byte(b >> uint(rand.Intn(9)))
+	},
+}
+
+func (s *Sniffer) fuzz(data []byte) int {
+	changes := 0
+	for off, b := range data {
+		if rand.Float64() > s.fuzzRatio {
+			continue
+		}
+
+		data[off] = mutators[rand.Intn(len(mutators))](b)
+		changes++
+	}
+	return changes
+}
+
+func (s *Sniffer) doFuzzing(pkt gopacket.Packet) {
+	if rand.Float64() > s.fuzzRate {
+		return
+	}
+
+	layersChanged := 0
+	bytesChanged := 0
+
+	for _, fuzzLayerType := range s.fuzzLayers {
+		for _, layer := range pkt.Layers() {
+			if layer.LayerType().String() == fuzzLayerType {
+				fuzzData := layer.LayerContents()
+				changes := s.fuzz(fuzzData)
+				if changes > 0 {
+					layersChanged++
+					bytesChanged += changes
+				}
+
+			}
+		}
+	}
+
+	if bytesChanged > 0 {
+		logFn := log.Info
+		if s.fuzzSilent {
+			logFn = log.Debug
+		}
+		logFn("[%s] changed %d bytes in %d layers.", tui.Green("net.fuzz"), bytesChanged, layersChanged)
+		if err := s.Session.Queue.Send(pkt.Data()); err != nil {
+			log.Error("error sending fuzzed packet: %s", err)
+		}
+	}
+}
+
+func (s *Sniffer) configureFuzzing() (err error) {
+	layers := ""
+
+	if err, layers = s.StringParam("net.fuzz.layers"); err != nil {
+		return
+	} else {
+		s.fuzzLayers = str.Comma(layers)
+	}
+
+	if err, s.fuzzRate = s.DecParam("net.fuzz.rate"); err != nil {
+		return
+	}
+
+	if err, s.fuzzRatio = s.DecParam("net.fuzz.ratio"); err != nil {
+		return
+	}
+
+	if err, s.fuzzSilent = s.BoolParam("net.fuzz.silent"); err != nil {
+		return
+	}
+
+	return
+}
+
+func (s *Sniffer) StartFuzzing() error {
+	if s.fuzzActive {
+		return nil
+	}
+
+	if err := s.configureFuzzing(); err != nil {
+		return err
+	} else if !s.Running() {
+		if err := s.Start(); err != nil {
+			return err
+		}
+	}
+
+	s.fuzzActive = true
+
+	log.Info("[%s] active on layer types %s (rate:%f ratio:%f)", tui.Green("net.fuzz"), strings.Join(s.fuzzLayers, ","), s.fuzzRate, s.fuzzRatio)
+
+	return nil
+}
+
+func (s *Sniffer) StopFuzzing() error {
+	s.fuzzActive = false
+	return nil
+}