new: implemented mDNS server / spoofer (closes #542)

modules/mdns_server/mdns_server.go

@@ -0,0 +1,160 @@
+package mdns_server
+
+import (
+	"fmt"
+	"io/ioutil"
+	"log"
+	"net"
+	"os"
+
+	"github.com/bettercap/bettercap/session"
+
+	"github.com/evilsocket/islazy/str"
+	"github.com/evilsocket/islazy/tui"
+
+	"github.com/hashicorp/mdns"
+)
+
+type MDNSServer struct {
+	session.SessionModule
+	hostname string
+	instance string
+	service  *mdns.MDNSService
+	server   *mdns.Server
+}
+
+func NewMDNSServer(s *session.Session) *MDNSServer {
+	host, _ := os.Hostname()
+	mod := &MDNSServer{
+		SessionModule: session.NewSessionModule("mdns.server", s),
+		hostname:      host,
+	}
+
+	mod.AddParam(session.NewStringParameter("mdns.server.host",
+		mod.hostname+".",
+		"",
+		"mDNS hostname to advertise on the network."))
+
+	mod.AddParam(session.NewStringParameter("mdns.server.service",
+		"_companion-link._tcp.",
+		"",
+		"mDNS service name to advertise on the network."))
+
+	mod.AddParam(session.NewStringParameter("mdns.server.domain",
+		"local.",
+		"",
+		"mDNS domain."))
+
+	mod.AddParam(session.NewStringParameter("mdns.server.address",
+		session.ParamIfaceAddress,
+		session.IPv4Validator,
+		"IPv4 address of the mDNS service."))
+
+	mod.AddParam(session.NewStringParameter("mdns.server.address6",
+		session.ParamIfaceAddress6,
+		session.IPv6Validator,
+		"IPv6 address of the mDNS service."))
+
+	mod.AddParam(session.NewIntParameter("mdns.server.port",
+		"52377",
+		"Port of the mDNS service."))
+
+	mod.AddParam(session.NewStringParameter("mdns.server.info",
+		"rpBA=DE:AD:BE:EF:CA:FE, rpAD=abf99d4ff73f, rpHI=ec5fb3caf528, rpHN=20f8fb46e2eb, rpVr=164.16, rpHA=7406bd0eff69",
+		"",
+		"Comma separated list of informative TXT records for the mDNS server."))
+
+	mod.AddHandler(session.NewModuleHandler("mdns.server on", "",
+		"Start mDNS server.",
+		func(args []string) error {
+			return mod.Start()
+		}))
+
+	mod.AddHandler(session.NewModuleHandler("mdns.server off", "",
+		"Stop mDNS server.",
+		func(args []string) error {
+			return mod.Stop()
+		}))
+
+	return mod
+}
+
+func (mod *MDNSServer) Name() string {
+	return "mdns.server"
+}
+
+func (mod *MDNSServer) Description() string {
+	return "A mDNS server module to create multicast services or spoof existing ones."
+}
+
+func (mod *MDNSServer) Author() string {
+	return "Simone Margaritelli <evilsocket@gmail.com>"
+}
+
+func (mod *MDNSServer) Configure() (err error) {
+	if mod.Running() {
+		return session.ErrAlreadyStarted(mod.Name())
+	}
+
+	var host string
+	var service string
+	var domain string
+	var ip4 string
+	var ip6 string
+	var port int
+	var info string
+
+	if err, host = mod.StringParam("mdns.server.host"); err != nil {
+		return err
+	} else if err, service = mod.StringParam("mdns.server.service"); err != nil {
+		return err
+	} else if err, domain = mod.StringParam("mdns.server.domain"); err != nil {
+		return err
+	} else if err, ip4 = mod.StringParam("mdns.server.address"); err != nil {
+		return err
+	} else if err, ip6 = mod.StringParam("mdns.server.address6"); err != nil {
+		return err
+	} else if err, port = mod.IntParam("mdns.server.port"); err != nil {
+		return err
+	} else if err, info = mod.StringParam("mdns.server.info"); err != nil {
+		return err
+	}
+
+	log.SetOutput(ioutil.Discard)
+
+	mod.instance = fmt.Sprintf("%s%s%s", host, service, domain)
+	mod.service, err = mdns.NewMDNSService(
+		mod.instance,
+		service,
+		domain,
+		host,
+		port,
+		[]net.IP{
+			net.ParseIP(ip4),
+			net.ParseIP(ip6),
+		},
+		str.Comma(info))
+
+	return err
+}
+
+func (mod *MDNSServer) Start() error {
+	if err := mod.Configure(); err != nil {
+		return err
+	}
+
+	return mod.SetRunning(true, func() {
+		var err error
+		mod.Info("advertising service %s -> %s:%d", tui.Bold(mod.instance), mod.service.IPs, mod.service.Port)
+		if mod.server, err = mdns.NewServer(&mdns.Config{Zone: mod.service}); err != nil {
+			mod.Error("%v", err)
+			mod.Stop()
+		}
+	})
+}
+
+func (mod *MDNSServer) Stop() error {
+	return mod.SetRunning(false, func() {
+		mod.server.Shutdown()
+	})
+}