From 76792ffc0b262bc3de9d7ef4d0c53a21697c6cc3 Mon Sep 17 00:00:00 2001
From: Wim <wim@42.be>
Date: Tue, 2 Jun 2015 23:47:18 +0200
Subject: [PATCH] Send SOA with negative responses

---
 command/agent/dns.go      |  3 ++
 command/agent/dns_test.go | 76 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 79 insertions(+)

diff --git a/command/agent/dns.go b/command/agent/dns.go
index f4d8bb8891dc..d1ef0d1be665 100644
--- a/command/agent/dns.go
+++ b/command/agent/dns.go
@@ -333,6 +333,7 @@ PARSE:
 	return
 INVALID:
 	d.logger.Printf("[WARN] dns: QName invalid: %s", qName)
+	d.addSOA(d.domain, resp)
 	resp.SetRcode(req, dns.RcodeNameError)
 }
 
@@ -367,6 +368,7 @@ RPC:
 
 	// If we have no address, return not found!
 	if out.NodeServices == nil {
+		d.addSOA(d.domain, resp)
 		resp.SetRcode(req, dns.RcodeNameError)
 		return
 	}
@@ -469,6 +471,7 @@ RPC:
 
 	// If we have no nodes, return not found!
 	if len(out.Nodes) == 0 {
+		d.addSOA(d.domain, resp)
 		resp.SetRcode(req, dns.RcodeNameError)
 		return
 	}
diff --git a/command/agent/dns_test.go b/command/agent/dns_test.go
index ec584a1cd2d1..47fb26d2c7eb 100644
--- a/command/agent/dns_test.go
+++ b/command/agent/dns_test.go
@@ -157,6 +157,28 @@ func TestDNS_NodeLookup(t *testing.T) {
 	if aRec.Hdr.Ttl != 0 {
 		t.Fatalf("Bad: %#v", in.Answer[0])
 	}
+
+	// lookup a non-existing node, we should receive a SOA
+	m = new(dns.Msg)
+	m.SetQuestion("nofoo.node.dc1.consul.", dns.TypeANY)
+
+	c = new(dns.Client)
+	in, _, err = c.Exchange(m, addr.String())
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	if len(in.Ns) != 1 {
+		t.Fatalf("Bad: %#v", in, len(in.Answer))
+	}
+
+	soaRec, ok := in.Ns[0].(*dns.SOA)
+	if !ok {
+		t.Fatalf("Bad: %#v", in.Ns[0])
+	}
+	if soaRec.Hdr.Ttl != 0 {
+		t.Fatalf("Bad: %#v", in.Ns[0])
+	}
 }
 
 func TestDNS_CaseInsensitiveNodeLookup(t *testing.T) {
@@ -524,6 +546,29 @@ func TestDNS_ServiceLookup(t *testing.T) {
 	if aRec.Hdr.Ttl != 0 {
 		t.Fatalf("Bad: %#v", in.Extra[0])
 	}
+
+	// lookup a non-existing service, we should receive a SOA
+	m = new(dns.Msg)
+	m.SetQuestion("nodb.service.consul.", dns.TypeSRV)
+
+	c = new(dns.Client)
+	addr, _ = srv.agent.config.ClientListener("", srv.agent.config.Ports.DNS)
+	in, _, err = c.Exchange(m, addr.String())
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	if len(in.Ns) != 1 {
+		t.Fatalf("Bad: %#v", in)
+	}
+
+	soaRec, ok := in.Ns[0].(*dns.SOA)
+	if !ok {
+		t.Fatalf("Bad: %#v", in.Ns[0])
+	}
+	if soaRec.Hdr.Ttl != 0 {
+		t.Fatalf("Bad: %#v", in.Ns[0])
+	}
 }
 
 func TestDNS_ServiceLookup_ServiceAddress(t *testing.T) {
@@ -1692,3 +1737,34 @@ func TestDNS_ServiceLookup_SRV_RFC_TCP_Default(t *testing.T) {
 		t.Fatalf("Bad: %#v", in.Extra[0])
 	}
 }
+
+func TestDNS_NonExistingLookup(t *testing.T) {
+	dir, srv := makeDNSServer(t, nil, nil)
+	defer os.RemoveAll(dir)
+	defer srv.agent.Shutdown()
+
+	addr, _ := srv.agent.config.ClientListener("", srv.agent.config.Ports.DNS)
+
+	// lookup a non-existing node, we should receive a SOA
+	m := new(dns.Msg)
+	m.SetQuestion("nonexisting.consul.", dns.TypeANY)
+
+	c := new(dns.Client)
+	in, _, err := c.Exchange(m, addr.String())
+	if err != nil {
+		t.Fatalf("err: %v", err)
+	}
+
+	if len(in.Ns) != 1 {
+		t.Fatalf("Bad: %#v", in, len(in.Answer))
+	}
+
+	soaRec, ok := in.Ns[0].(*dns.SOA)
+	if !ok {
+		t.Fatalf("Bad: %#v", in.Ns[0])
+	}
+	if soaRec.Hdr.Ttl != 0 {
+		t.Fatalf("Bad: %#v", in.Ns[0])
+	}
+
+}