// Check that the cache keeps its intended capacity constant
func TestCacheLength(t *testing.T) {
InitDefaultLogging(testing.Verbose())
Info.Println("TestCacheLength starting")
const cacheLen = 128
l, err := NewCache(cacheLen, nil)
wt.AssertNoErr(t, err)
insTime := time.Now()
t.Logf("Inserting 256 questions in the cache at '%s', with TTL from 0 to 255", insTime)
for i := 0; i < cacheLen*2; i++ {
name := fmt.Sprintf("name%d", i)
questionMsg := new(dns.Msg)
questionMsg.SetQuestion(name, dns.TypeA)
questionMsg.RecursionDesired = true
question := &questionMsg.Question[0]
ip := net.ParseIP(fmt.Sprintf("10.0.1.%d", i))
records := []ZoneRecord{Record{name, ip, 0, 0, 0}}
reply := makeAddressReply(questionMsg, question, records)
reply.Answer[0].Header().Ttl = uint32(i)
l.Put(questionMsg, reply, 0, 0)
}
wt.AssertEqualInt(t, l.Len(), cacheLen, "cache length")
minExpectedTime := insTime.Add(time.Duration(cacheLen) * time.Second)
t.Logf("Checking all remaining entries expire after insert_time + %d secs='%s'", cacheLen, minExpectedTime)
for _, entry := range l.entries {
if entry.validUntil.Before(minExpectedTime) {
t.Fatalf("Entry valid until %s", entry.validUntil)
}
}
}
// 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")
}
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)")
}