Example #1
0
// Check that the cache entries are ok
func TestCacheEntries(t *testing.T) {
	InitDefaultLogging(testing.Verbose())
	Info.Println("TestCacheEntries starting")

	Info.Println("Checking cache consistency")

	const cacheLen = 128
	clk := clock.NewMock()

	l, err := NewCache(cacheLen, clk)
	wt.AssertNoErr(t, err)

	questionMsg := new(dns.Msg)
	questionMsg.SetQuestion("some.name", dns.TypeA)
	questionMsg.RecursionDesired = true

	question := &questionMsg.Question[0]

	t.Logf("Trying to get a name")
	resp, err := l.Get(questionMsg, minUDPSize)
	wt.AssertNoErr(t, err)
	if resp != nil {
		t.Logf("Got\n%s", resp)
		t.Fatalf("ERROR: Did not expect a reponse from Get() yet")
	}
	t.Logf("Trying to get it again")
	resp, err = l.Get(questionMsg, minUDPSize)
	wt.AssertNoErr(t, err)
	if resp != nil {
		t.Logf("Got\n%s", resp)
		t.Fatalf("ERROR: Did not expect a reponse from Get() yet")
	}

	t.Logf("Inserting the reply")
	records := []ZoneRecord{Record{"some.name", net.ParseIP("10.0.1.1"), 0, 0, 0}}
	reply1 := makeAddressReply(questionMsg, question, records)
	l.Put(questionMsg, reply1, nullTTL, 0)

	t.Logf("Checking we can Get() the reply now")
	resp, err = l.Get(questionMsg, minUDPSize)
	wt.AssertNoErr(t, err)
	wt.AssertTrue(t, resp != nil, "reponse from Get()")
	t.Logf("Received '%s'", resp.Answer[0])
	wt.AssertType(t, resp.Answer[0], (*dns.A)(nil), "DNS record")
	ttlGet1 := resp.Answer[0].Header().Ttl

	clk.Add(time.Duration(1) * time.Second)
	t.Logf("Checking that a second Get(), after 1 second, gets the same result, but with reduced TTL")
	resp, err = l.Get(questionMsg, minUDPSize)
	wt.AssertNoErr(t, err)
	wt.AssertTrue(t, resp != nil, "reponse from a second Get()")
	t.Logf("Received '%s'", resp.Answer[0])
	wt.AssertType(t, resp.Answer[0], (*dns.A)(nil), "DNS record")
	ttlGet2 := resp.Answer[0].Header().Ttl
	wt.AssertEqualInt(t, int(ttlGet1-ttlGet2), 1, "TTL difference")

	clk.Add(time.Duration(localTTL) * time.Second)
	t.Logf("Checking that a third Get(), after %d second, gets no result", localTTL)
	resp, err = l.Get(questionMsg, minUDPSize)
	wt.AssertNoErr(t, err)
	if resp != nil {
		t.Logf("Got\n%s", resp)
		t.Fatalf("ERROR: Did NOT expect a reponse from the second Get()")
	}

	t.Logf("Checking that an Remove() results in Get() returning nothing")
	records = []ZoneRecord{Record{"some.name", net.ParseIP("10.0.9.9"), 0, 0, 0}}
	replyTemp := makeAddressReply(questionMsg, question, records)
	l.Put(questionMsg, replyTemp, nullTTL, 0)
	lenBefore := l.Len()
	l.Remove(question)
	wt.AssertEqualInt(t, l.Len(), lenBefore-1, "cache length")
	l.Remove(question) // do it again: should have no effect...
	wt.AssertEqualInt(t, l.Len(), lenBefore-1, "cache length")

	resp, err = l.Get(questionMsg, minUDPSize)
	wt.AssertNoErr(t, err)
	wt.AssertTrue(t, resp == nil, "reponse from the Get() after a Remove()")

	t.Logf("Inserting a two replies for the same query")
	records = []ZoneRecord{Record{"some.name", net.ParseIP("10.0.1.2"), 0, 0, 0}}
	reply2 := makeAddressReply(questionMsg, question, records)
	l.Put(questionMsg, reply2, nullTTL, 0)
	clk.Add(time.Duration(1) * time.Second)
	records = []ZoneRecord{Record{"some.name", net.ParseIP("10.0.1.3"), 0, 0, 0}}
	reply3 := makeAddressReply(questionMsg, question, records)
	l.Put(questionMsg, reply3, nullTTL, 0)

	t.Logf("Checking we get the last one...")
	resp, err = l.Get(questionMsg, minUDPSize)
	wt.AssertNoErr(t, err)
	wt.AssertTrue(t, resp != nil, "reponse from the Get()")
	t.Logf("Received '%s'", resp.Answer[0])
	wt.AssertType(t, resp.Answer[0], (*dns.A)(nil), "DNS record")
	wt.AssertEqualString(t, resp.Answer[0].(*dns.A).A.String(), "10.0.1.3", "IP address")
	wt.AssertEqualInt(t, int(resp.Answer[0].Header().Ttl), int(localTTL), "TTL")

	clk.Add(time.Duration(localTTL-1) * time.Second)
	resp, err = l.Get(questionMsg, minUDPSize)
	wt.AssertNoErr(t, err)
	wt.AssertTrue(t, resp != nil, "reponse from the Get()")
	t.Logf("Received '%s'", resp.Answer[0])
	wt.AssertType(t, resp.Answer[0], (*dns.A)(nil), "DNS record")
	wt.AssertEqualString(t, resp.Answer[0].(*dns.A).A.String(), "10.0.1.3", "IP address")
	wt.AssertEqualInt(t, int(resp.Answer[0].Header().Ttl), 1, "TTL")

	t.Logf("Checking we get empty replies when they are expired...")
	lenBefore = l.Len()
	clk.Add(time.Duration(localTTL) * time.Second)
	resp, err = l.Get(questionMsg, minUDPSize)
	wt.AssertNoErr(t, err)
	if resp != nil {
		t.Logf("Got\n%s", resp.Answer[0])
		t.Fatalf("ERROR: Did NOT expect a reponse from the Get()")
	}
	wt.AssertEqualInt(t, l.Len(), lenBefore-1, "cache length (after getting an expired entry)")

	questionMsg2 := new(dns.Msg)
	questionMsg2.SetQuestion("some.other.name", dns.TypeA)
	questionMsg2.RecursionDesired = true
	question2 := &questionMsg2.Question[0]

	t.Logf("Trying to Get() a name")
	resp, err = l.Get(questionMsg2, minUDPSize)
	wt.AssertNoErr(t, err)
	wt.AssertNil(t, resp, "reponse from Get() yet")

	t.Logf("Checking that an Remove() between Get() and Put() does not break things")
	records = []ZoneRecord{Record{"some.name", net.ParseIP("10.0.9.9"), 0, 0, 0}}
	replyTemp2 := makeAddressReply(questionMsg2, question2, records)
	l.Remove(question2)
	l.Put(questionMsg2, replyTemp2, nullTTL, 0)
	resp, err = l.Get(questionMsg2, minUDPSize)
	wt.AssertNoErr(t, err)
	wt.AssertNotNil(t, resp, "reponse from Get()")

	questionMsg3 := new(dns.Msg)
	questionMsg3.SetQuestion("some.other.name", dns.TypeA)
	questionMsg3.RecursionDesired = true
	question3 := &questionMsg3.Question[0]

	t.Logf("Checking that a entry with CacheNoLocalReplies return an error")
	l.Put(questionMsg3, nil, nullTTL, CacheNoLocalReplies)
	resp, err = l.Get(questionMsg3, minUDPSize)
	wt.AssertNil(t, resp, "Get() response with CacheNoLocalReplies")
	wt.AssertNotNil(t, err, "Get() error with CacheNoLocalReplies")

	clk.Add(time.Second * time.Duration(negLocalTTL+1))
	t.Logf("Checking that we get an expired response after %f seconds", negLocalTTL)
	resp, err = l.Get(questionMsg3, minUDPSize)
	wt.AssertNil(t, resp, "expired Get() response with CacheNoLocalReplies")
	wt.AssertNil(t, err, "expired Get() error with CacheNoLocalReplies")

	l.Remove(question3)
	t.Logf("Checking that Put&Get with CacheNoLocalReplies with a Remove in the middle returns nothing")
	l.Put(questionMsg3, nil, nullTTL, CacheNoLocalReplies)
	l.Remove(question3)
	resp, err = l.Get(questionMsg3, minUDPSize)
	wt.AssertNil(t, resp, "Get() reponse with CacheNoLocalReplies")
	wt.AssertNil(t, err, "Get() error with CacheNoLocalReplies")
}
Example #2
0
func TestTCPDNSServer(t *testing.T) {
	setupForTest(t)
	const (
		numAnswers   = 512
		nonLocalName = "weave.works."
	)
	dnsAddr := fmt.Sprintf("localhost:%d", testPort)

	InitDefaultLogging(true)
	var zone = NewZoneDb(DefaultLocalDomain)

	// generate a list of `numAnswers` IP addresses
	var addrs []ZoneRecord
	bs := make([]byte, 4)
	for i := 0; i < numAnswers; i++ {
		binary.LittleEndian.PutUint32(bs, uint32(i))
		addrs = append(addrs, Record{"", net.IPv4(bs[0], bs[1], bs[2], bs[3]), 0, 0, 0})
	}

	// handler for the fallback server: it will just return a very long response
	fallbackUDPHandler := func(w dns.ResponseWriter, req *dns.Msg) {
		maxLen := getMaxReplyLen(req, protUDP)

		t.Logf("Fallback UDP server got asked: returning %d answers", numAnswers)
		q := req.Question[0]
		m := makeAddressReply(req, &q, addrs)
		mLen := m.Len()
		m.SetEdns0(uint16(maxLen), false)

		if mLen > maxLen {
			t.Logf("... truncated response (%d > %d)", mLen, maxLen)
			m.Truncated = true
		}
		w.WriteMsg(m)
	}
	fallbackTCPHandler := func(w dns.ResponseWriter, req *dns.Msg) {
		t.Logf("Fallback TCP server got asked: returning %d answers", numAnswers)
		q := req.Question[0]
		m := makeAddressReply(req, &q, addrs)
		w.WriteMsg(m)
	}

	t.Logf("Running a DNS fallback server with UDP")
	us, fallbackUDPAddr, err := runLocalUDPServer(t, "127.0.0.1:0", fallbackUDPHandler)
	wt.AssertNoErr(t, err)
	defer us.Shutdown()

	_, fallbackPort, err := net.SplitHostPort(fallbackUDPAddr)
	wt.AssertNoErr(t, err)

	t.Logf("Starting another fallback server, with TCP, on the same port as the UDP server")
	fallbackTCPAddr := fmt.Sprintf("127.0.0.1:%s", fallbackPort)
	ts, fallbackTCPAddr, err := runLocalTCPServer(t, fallbackTCPAddr, fallbackTCPHandler)
	wt.AssertNoErr(t, err)
	defer ts.Shutdown()

	t.Logf("Creating a WeaveDNS server instance, falling back to 127.0.0.1:%s", fallbackPort)
	config := &dns.ClientConfig{Servers: []string{"127.0.0.1"}, Port: fallbackPort}
	srv, err := NewDNSServer(DNSServerConfig{UpstreamCfg: config, Port: testPort}, zone, nil)
	wt.AssertNoErr(t, err)
	defer srv.Stop()
	go srv.Start()
	time.Sleep(100 * time.Millisecond) // Allow sever goroutine to start

	t.Logf("Creating a UDP and a TCP client")
	uc := new(dns.Client)
	uc.UDPSize = minUDPSize
	tc := new(dns.Client)
	tc.Net = "tcp"

	t.Logf("Creating DNS query message")
	m := new(dns.Msg)
	m.RecursionDesired = true
	m.SetQuestion(nonLocalName, dns.TypeA)

	t.Logf("Checking the fallback server at %s returns a truncated response with UDP", fallbackUDPAddr)
	r, _, err := uc.Exchange(m, fallbackUDPAddr)
	t.Logf("Got response from fallback server (UDP) with %d answers", len(r.Answer))
	t.Logf("Response:\n%+v\n", r)
	wt.AssertNoErr(t, err)
	wt.AssertTrue(t, r.MsgHdr.Truncated, "DNS truncated reponse flag")
	wt.AssertNotEqualInt(t, len(r.Answer), numAnswers, "number of answers (UDP)")

	t.Logf("Checking the WeaveDNS server at %s returns a truncated reponse with UDP", dnsAddr)
	r, _, err = uc.Exchange(m, dnsAddr)
	t.Logf("UDP Response:\n%+v\n", r)
	wt.AssertNoErr(t, err)
	wt.AssertNotNil(t, r, "response")
	t.Logf("%d answers", len(r.Answer))
	wt.AssertTrue(t, r.MsgHdr.Truncated, "DNS truncated reponse flag")
	wt.AssertNotEqualInt(t, len(r.Answer), numAnswers, "number of answers (UDP)")

	t.Logf("Checking the WeaveDNS server at %s does not return a truncated reponse with TCP", dnsAddr)
	r, _, err = tc.Exchange(m, dnsAddr)
	t.Logf("TCP Response:\n%+v\n", r)
	wt.AssertNoErr(t, err)
	wt.AssertNotNil(t, r, "response")
	t.Logf("%d answers", len(r.Answer))
	wt.AssertFalse(t, r.MsgHdr.Truncated, "DNS truncated response flag")
	wt.AssertEqualInt(t, len(r.Answer), numAnswers, "number of answers (TCP)")

	t.Logf("Checking the WeaveDNS server at %s does not return a truncated reponse with UDP with a bigger buffer", dnsAddr)
	m.SetEdns0(testUDPBufSize, false)
	r, _, err = uc.Exchange(m, dnsAddr)
	t.Logf("UDP-large Response:\n%+v\n", r)
	wt.AssertNoErr(t, err)
	wt.AssertNotNil(t, r, "response")
	t.Logf("%d answers", len(r.Answer))
	wt.AssertNoErr(t, err)
	wt.AssertFalse(t, r.MsgHdr.Truncated, "DNS truncated response flag")
	wt.AssertEqualInt(t, len(r.Answer), numAnswers, "number of answers (UDP-long)")
}