package dns import ( "encoding/hex" "fmt" "net" "testing" ) func TestCompressLength(t *testing.T) { m := new(Msg) m.SetQuestion("miek.nl", TypeMX) ul := m.Len() m.Compress = true if ul != m.Len() { t.Fatalf("should be equal") } } // Does the predicted length match final packed length? func TestMsgCompressLength(t *testing.T) { makeMsg := func(question string, ans, ns, e []RR) *Msg { msg := new(Msg) msg.SetQuestion(Fqdn(question), TypeANY) msg.Answer = append(msg.Answer, ans...) msg.Ns = append(msg.Ns, ns...) msg.Extra = append(msg.Extra, e...) msg.Compress = true return msg } name1 := "12345678901234567890123456789012345.12345678.123." rrA := testRR(name1 + " 3600 IN A 192.0.2.1") rrMx := testRR(name1 + " 3600 IN MX 10 " + name1) tests := []*Msg{ makeMsg(name1, []RR{rrA}, nil, nil), makeMsg(name1, []RR{rrMx, rrMx}, nil, nil)} for _, msg := range tests { predicted := msg.Len() buf, err := msg.Pack() if err != nil { t.Error(err) } if predicted < len(buf) { t.Errorf("predicted compressed length is wrong: predicted %s (len=%d) %d, actual %d", msg.Question[0].Name, len(msg.Answer), predicted, len(buf)) } } } func TestMsgLength(t *testing.T) { makeMsg := func(question string, ans, ns, e []RR) *Msg { msg := new(Msg) msg.SetQuestion(Fqdn(question), TypeANY) msg.Answer = append(msg.Answer, ans...) msg.Ns = append(msg.Ns, ns...) msg.Extra = append(msg.Extra, e...) return msg } name1 := "12345678901234567890123456789012345.12345678.123." rrA := testRR(name1 + " 3600 IN A 192.0.2.1") rrMx := testRR(name1 + " 3600 IN MX 10 " + name1) tests := []*Msg{ makeMsg(name1, []RR{rrA}, nil, nil), makeMsg(name1, []RR{rrMx, rrMx}, nil, nil)} for _, msg := range tests { predicted := msg.Len() buf, err := msg.Pack() if err != nil { t.Error(err) } if predicted < len(buf) { t.Errorf("predicted length is wrong: predicted %s (len=%d), actual %d", msg.Question[0].Name, predicted, len(buf)) } } } func TestMsgLength2(t *testing.T) { // Serialized replies var testMessages = []string{ // google.com. IN A? "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", // amazon.com. IN A? (reply has no EDNS0 record) // TODO(miek): this one is off-by-one, need to find out why //"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", // yahoo.com. IN A? "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", // microsoft.com. IN A? "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", // google.com. IN MX? "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", // reddit.com. IN A? "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", } for i, hexData := range testMessages { // we won't fail the decoding of the hex input, _ := hex.DecodeString(hexData) m := new(Msg) m.Unpack(input) m.Compress = true lenComp := m.Len() b, _ := m.Pack() pacComp := len(b) m.Compress = false lenUnComp := m.Len() b, _ = m.Pack() pacUnComp := len(b) if pacComp+1 != lenComp { t.Errorf("msg.Len(compressed)=%d actual=%d for test %d", lenComp, pacComp, i) } if pacUnComp+1 != lenUnComp { t.Errorf("msg.Len(uncompressed)=%d actual=%d for test %d", lenUnComp, pacUnComp, i) } } } func TestMsgLengthCompressionMalformed(t *testing.T) { // SOA with empty hostmaster, which is illegal soa := &SOA{Hdr: RR_Header{Name: ".", Rrtype: TypeSOA, Class: ClassINET, Ttl: 12345}, Ns: ".", Mbox: "", Serial: 0, Refresh: 28800, Retry: 7200, Expire: 604800, Minttl: 60} m := new(Msg) m.Compress = true m.Ns = []RR{soa} m.Len() // Should not crash. } func TestMsgCompressLength2(t *testing.T) { msg := new(Msg) msg.Compress = true msg.SetQuestion(Fqdn("bliep."), TypeANY) msg.Answer = append(msg.Answer, &SRV{Hdr: RR_Header{Name: "blaat.", Rrtype: 0x21, Class: 0x1, Ttl: 0x3c}, Port: 0x4c57, Target: "foo.bar."}) msg.Extra = append(msg.Extra, &A{Hdr: RR_Header{Name: "foo.bar.", Rrtype: 0x1, Class: 0x1, Ttl: 0x3c}, A: net.IP{0xac, 0x11, 0x0, 0x3}}) predicted := msg.Len() buf, err := msg.Pack() if err != nil { t.Error(err) } if predicted != len(buf) { t.Errorf("predicted compressed length is wrong: predicted %s (len=%d) %d, actual %d", msg.Question[0].Name, len(msg.Answer), predicted, len(buf)) } } func TestMsgCompressLengthLargeRecords(t *testing.T) { msg := new(Msg) msg.Compress = true msg.SetQuestion("my.service.acme.", TypeSRV) j := 1 for i := 0; i < 250; i++ { target := fmt.Sprintf("host-redis-%d-%d.test.acme.com.node.dc1.consul.", j, i) msg.Answer = append(msg.Answer, &SRV{Hdr: RR_Header{Name: "redis.service.consul.", Class: 1, Rrtype: TypeSRV, Ttl: 0x3c}, Port: 0x4c57, Target: target}) msg.Extra = append(msg.Extra, &CNAME{Hdr: RR_Header{Name: target, Class: 1, Rrtype: TypeCNAME, Ttl: 0x3c}, Target: fmt.Sprintf("fx.168.%d.%d.", j, i)}) } predicted := msg.Len() buf, err := msg.Pack() if err != nil { t.Error(err) } if predicted != len(buf) { t.Fatalf("predicted compressed length is wrong: predicted %s (len=%d) %d, actual %d", msg.Question[0].Name, len(msg.Answer), predicted, len(buf)) } }