newstuff

ex/fks-shield/shield.go

@@ -0,0 +1,86 @@
+/* 
+ * Funkensturm, a versatile DNS proxy
+ * Miek Gieben <miek@miek.nl> (c) 2011
+ * GPLv2
+ */
+
+package main
+
+import (
+	"dns"
+	"flag"
+	"log"
+	"os/signal"
+	"strings"
+)
+
+func doFunkenSturm(pkt *dns.Msg) (ret []byte) {
+	// No matter what, we refuse to answer requests with the response bit set.
+	if pkt.MsgHdr.Response == true {
+		return nil
+	}
+
+	// Loop through the Funks and decide what to do with the packet.
+	for _, f := range f.Funk {
+		if m, ok := f.Match(pkt); ok {
+			ret = f.Action(m)
+			return
+		}
+	}
+	if f.Default == nil {
+		println("No f.Default set!")
+		return
+	}
+	ret = f.Default(pkt)
+	return
+}
+
+func serve(w dns.ResponseWriter, req *dns.Msg) {
+	if out := doFunkenSturm(req); out != nil {
+		w.Write(out)
+	}
+}
+
+func listenAndServe(add, net string) {
+	if err := dns.ListenAndServe(add, net, nil); err != nil {
+		log.Printf("fks-shield: failed to setup:", net, add)
+	}
+}
+
+func main() {
+	listen := flag.String("listen", "127.0.0.1:8053", "set the listener address")
+	server := flag.String("server", "127.0.0.1:53", "remote server address(es), seperate with commas")
+	verbose = flag.Bool("verbose", false, "Print packet as it flows through")
+	flag.Usage = func() {
+		flag.PrintDefaults()
+	}
+	flag.Parse()
+
+	clients := strings.Split(*server, ",")
+	qr = make([]*FunkClient, len(clients))
+	for i, ra := range clients {
+		qr[i] = new(FunkClient)
+		qr[i].Client = dns.NewClient()
+		qr[i].Addr = ra
+	}
+
+	f = NewFunkenSturm()
+	ok := f.Setup()
+	if !ok {
+		println("Setup failed")
+		return
+	}
+
+	dns.HandleFunc(".", serve)
+	go listenAndServe(*listen, "tcp")
+	go listenAndServe(*listen, "udp")
+
+forever:
+	for {
+		select {
+		case <-signal.Incoming:
+			println("Signal received, stopping")
+			break forever
+		}
+	}
+}