// Copyright (c) Tailscale Inc & AUTHORS // SPDX-License-Identifier: BSD-3-Clause package resolver import ( "flag" "fmt" "reflect" "strings" "testing" "time" dns "golang.org/x/net/dns/dnsmessage" "tailscale.com/types/dnstype" ) func (rr resolverAndDelay) String() string { return fmt.Sprintf("%v+%v", rr.name, rr.startDelay) } func TestResolversWithDelays(t *testing.T) { // query q := func(ss ...string) (ipps []*dnstype.Resolver) { for _, host := range ss { ipps = append(ipps, &dnstype.Resolver{Addr: host}) } return } // output o := func(ss ...string) (rr []resolverAndDelay) { for _, s := range ss { var d time.Duration s, durStr, hasPlus := strings.Cut(s, "+") if hasPlus { var err error d, err = time.ParseDuration(durStr) if err != nil { panic(fmt.Sprintf("parsing duration in %q: %v", s, err)) } } rr = append(rr, resolverAndDelay{ name: &dnstype.Resolver{Addr: s}, startDelay: d, }) } return } tests := []struct { name string in []*dnstype.Resolver want []resolverAndDelay }{ { name: "unknown-no-delays", in: q("1.2.3.4", "2.3.4.5"), want: o("1.2.3.4", "2.3.4.5"), }, { name: "google-all-ipv4", in: q("8.8.8.8", "8.8.4.4"), want: o("https://dns.google/dns-query", "8.8.8.8+0.5s", "8.8.4.4+0.7s"), }, { name: "google-only-ipv6", in: q("2001:4860:4860::8888", "2001:4860:4860::8844"), want: o("https://dns.google/dns-query", "2001:4860:4860::8888+0.5s", "2001:4860:4860::8844+0.7s"), }, { name: "google-all-four", in: q("8.8.8.8", "8.8.4.4", "2001:4860:4860::8888", "2001:4860:4860::8844"), want: o("https://dns.google/dns-query", "8.8.8.8+0.5s", "8.8.4.4+0.7s", "2001:4860:4860::8888+0.5s", "2001:4860:4860::8844+0.7s"), }, { name: "quad9-one-v4-one-v6", in: q("9.9.9.9", "2620:fe::fe"), want: o("https://dns.quad9.net/dns-query", "9.9.9.9+0.5s", "2620:fe::fe+0.5s"), }, { name: "nextdns-ipv6-expand", in: q("2a07:a8c0::c3:a884"), want: o("https://dns.nextdns.io/c3a884"), }, { name: "nextdns-doh-input", in: q("https://dns.nextdns.io/c3a884"), want: o("https://dns.nextdns.io/c3a884"), }, } for _, tt := range tests { t.Run(tt.name, func(t *testing.T) { got := resolversWithDelays(tt.in) if !reflect.DeepEqual(got, tt.want) { t.Errorf("got %v; want %v", got, tt.want) } }) } } func TestGetRCode(t *testing.T) { tests := []struct { name string packet []byte want dns.RCode }{ { name: "empty", packet: []byte{}, want: dns.RCode(5), }, { name: "too-short", packet: []byte{0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, want: dns.RCode(5), }, { name: "noerror", packet: []byte{0xC4, 0xFE, 0x81, 0xA0, 0x00, 0x01, 0x00, 0x01, 0x00, 0x00, 0x00, 0x01}, want: dns.RCode(0), }, { name: "refused", packet: []byte{0xee, 0xa1, 0x81, 0x05, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01}, want: dns.RCode(5), }, { name: "nxdomain", packet: []byte{0x34, 0xf4, 0x81, 0x83, 0x00, 0x01, 0x00, 0x00, 0x00, 0x01, 0x00, 0x01}, want: dns.RCode(3), }, } for _, tt := range tests { t.Run(tt.name, func(t *testing.T) { got := getRCode(tt.packet) if got != tt.want { t.Errorf("got %d; want %d", got, tt.want) } }) } } var testDNS = flag.Bool("test-dns", false, "run tests that require a working DNS server") func TestGetKnownDoHClientForProvider(t *testing.T) { var fwd forwarder c, ok := fwd.getKnownDoHClientForProvider("https://dns.google/dns-query") if !ok { t.Fatal("not found") } if !*testDNS { t.Skip("skipping without --test-dns") } res, err := c.Head("https://dns.google/") if err != nil { t.Fatal(err) } defer res.Body.Close() t.Logf("Got: %+v", res) } func BenchmarkNameFromQuery(b *testing.B) { builder := dns.NewBuilder(nil, dns.Header{}) builder.StartQuestions() builder.Question(dns.Question{ Name: dns.MustNewName("foo.example."), Type: dns.TypeA, Class: dns.ClassINET, }) msg, err := builder.Finish() if err != nil { b.Fatal(err) } b.ResetTimer() b.ReportAllocs() for i := 0; i < b.N; i++ { _, err := nameFromQuery(msg) if err != nil { b.Fatal(err) } } } // Reproduces https://github.com/tailscale/tailscale/issues/2533 // Fixed by https://github.com/tailscale/tailscale/commit/f414a9cc01f3264912513d07c0244ff4f3e4ba54 // // NOTE: fuzz tests act like unit tests when run without `-fuzz` func FuzzClampEDNSSize(f *testing.F) { // Empty DNS packet f.Add([]byte{ // query id 0x12, 0x34, // flags: standard query, recurse 0x01, 0x20, // num questions 0x00, 0x00, // num answers 0x00, 0x00, // num authority RRs 0x00, 0x00, // num additional RRs 0x00, 0x00, }) // Empty OPT f.Add([]byte{ // header 0xaf, 0x66, 0x01, 0x20, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, // query 0x06, 0x67, 0x6f, 0x6f, 0x67, 0x6c, 0x65, 0x03, 0x63, 0x6f, 0x6d, 0x00, 0x00, 0x01, 0x00, 0x01, // OPT 0x00, // name: 0x00, 0x29, // type: OPT 0x10, 0x00, // UDP payload size 0x00, // higher bits in extended RCODE 0x00, // EDNS0 version 0x80, 0x00, // "Z" field 0x00, 0x00, // data length }) // Query for "google.com" f.Add([]byte{ // header 0xaf, 0x66, 0x01, 0x20, 0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, // query 0x06, 0x67, 0x6f, 0x6f, 0x67, 0x6c, 0x65, 0x03, 0x63, 0x6f, 0x6d, 0x00, 0x00, 0x01, 0x00, 0x01, // OPT 0x00, 0x00, 0x29, 0x10, 0x00, 0x00, 0x00, 0x80, 0x00, 0x00, 0x0c, 0x00, 0x0a, 0x00, 0x08, 0x62, 0x18, 0x1a, 0xcb, 0x19, 0xd7, 0xee, 0x23, }) f.Fuzz(func(t *testing.T, data []byte) { clampEDNSSize(data, maxResponseBytes) }) }