init dns.proxy

modules/dns_proxy/dns_proxy_script.go

@@ -0,0 +1,99 @@
+package dns_proxy
+
+import (
+	"github.com/bettercap/bettercap/v2/log"
+	"github.com/bettercap/bettercap/v2/session"
+	"github.com/evilsocket/islazy/plugin"
+
+	"github.com/miekg/dns"
+
+	"github.com/robertkrimen/otto"
+)
+
+type DnsProxyScript struct {
+	*plugin.Plugin
+
+	doOnRequest  bool
+	doOnResponse bool
+	doOnCommand  bool
+}
+
+func LoadDnsProxyScript(path string, sess *session.Session) (err error, s *DnsProxyScript) {
+	log.Debug("loading proxy script %s ...", path)
+
+	plug, err := plugin.Load(path)
+	if err != nil {
+		return
+	}
+
+	// define session pointer
+	if err = plug.Set("env", sess.Env.Data); err != nil {
+		log.Error("Error while defining environment: %+v", err)
+		return
+	}
+
+	// run onLoad if defined
+	if plug.HasFunc("onLoad") {
+		if _, err = plug.Call("onLoad"); err != nil {
+			log.Error("Error while executing onLoad callback: %s", "\nTraceback:\n  "+err.(*otto.Error).String())
+			return
+		}
+	}
+
+	s = &DnsProxyScript{
+		Plugin:       plug,
+		doOnRequest:  plug.HasFunc("onRequest"),
+		doOnResponse: plug.HasFunc("onResponse"),
+		doOnCommand:  plug.HasFunc("onCommand"),
+	}
+	return
+}
+
+func (s *DnsProxyScript) OnRequest(req *dns.Msg, clientIP string) (jsreq, jsres *JSQuery) {
+	if s.doOnRequest {
+		jsreq := NewJSQuery(req, clientIP)
+		jsres := NewJSQuery(req, clientIP)
+
+		if _, err := s.Call("onRequest", jsreq, jsres); err != nil {
+			log.Error("%s", err)
+			return nil, nil
+		} else if jsreq.WasModified() {
+			jsreq.UpdateHash()
+			return jsreq, nil
+		} else if jsres.WasModified() {
+			jsres.UpdateHash()
+			return nil, jsres
+		}
+	}
+
+	return nil, nil
+}
+
+func (s *DnsProxyScript) OnResponse(req, res *dns.Msg, clientIP string) (jsreq, jsres *JSQuery) {
+	if s.doOnResponse {
+		jsreq := NewJSQuery(req, clientIP)
+		jsres := NewJSQuery(res, clientIP)
+
+		if _, err := s.Call("onResponse", jsreq, jsres); err != nil {
+			log.Error("%s", err)
+			return nil, nil
+		} else if jsres.WasModified() {
+			jsres.UpdateHash()
+			return nil, jsres
+		}
+	}
+
+	return nil, nil
+}
+
+func (s *DnsProxyScript) OnCommand(cmd string) bool {
+	if s.doOnCommand {
+		if ret, err := s.Call("onCommand", cmd); err != nil {
+			log.Error("Error while executing onCommand callback: %+v", err)
+			return false
+		} else if v, ok := ret.(bool); ok {
+			return v
+		}
+	}
+	return false
+}