// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved. // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. package netcheck import ( "context" "fmt" "net" "reflect" "testing" "time" "tailscale.com/derp/derpmap" "tailscale.com/stun" "tailscale.com/stun/stuntest" ) func TestHairpinSTUN(t *testing.T) { c := &Client{ hairTX: stun.NewTxID(), gotHairSTUN: make(chan *net.UDPAddr, 1), } req := stun.Request(c.hairTX) if !stun.Is(req) { t.Fatal("expected STUN message") } if !c.handleHairSTUN(req, nil) { t.Fatal("expected true") } select { case <-c.gotHairSTUN: default: t.Fatal("expected value") } } func TestBasic(t *testing.T) { stunAddr, cleanup := stuntest.Serve(t) defer cleanup() c := &Client{ DERP: derpmap.NewTestWorld(stunAddr), Logf: t.Logf, } ctx, cancel := context.WithTimeout(context.Background(), 1*time.Second) defer cancel() r, err := c.GetReport(ctx) if err != nil { t.Fatal(err) } if !r.UDP { t.Error("want UDP") } if len(r.DERPLatency) != 1 { t.Errorf("expected 1 key in DERPLatency; got %+v", r.DERPLatency) } if _, ok := r.DERPLatency[stunAddr]; !ok { t.Errorf("expected key %q in DERPLatency; got %+v", stunAddr, r.DERPLatency) } if r.GlobalV4 == "" { t.Error("expected GlobalV4 set") } if r.PreferredDERP != 1 { t.Errorf("PreferredDERP = %v; want 1", r.PreferredDERP) } } func TestWorksWhenUDPBlocked(t *testing.T) { blackhole, err := net.ListenPacket("udp4", "127.0.0.1:0") if err != nil { t.Fatalf("failed to open blackhole STUN listener: %v", err) } defer blackhole.Close() stunAddr := blackhole.LocalAddr().String() c := &Client{ DERP: derpmap.NewTestWorld(stunAddr), Logf: t.Logf, } ctx, cancel := context.WithTimeout(context.Background(), 250*time.Millisecond) defer cancel() r, err := c.GetReport(ctx) if err != nil { t.Fatal(err) } want := &Report{ DERPLatency: map[string]time.Duration{}, } if !reflect.DeepEqual(r, want) { t.Errorf("mismatch\n got: %+v\nwant: %+v\n", r, want) } } func TestAddReportHistoryAndSetPreferredDERP(t *testing.T) { derps := derpmap.NewTestWorldWith( &derpmap.Server{ ID: 1, STUN4: "d1:1", }, &derpmap.Server{ ID: 2, STUN4: "d2:1", }, &derpmap.Server{ ID: 3, STUN4: "d3:1", }, ) // report returns a *Report from (DERP host, time.Duration)+ pairs. report := func(a ...interface{}) *Report { r := &Report{DERPLatency: map[string]time.Duration{}} for i := 0; i < len(a); i += 2 { k := a[i].(string) + ":1" switch v := a[i+1].(type) { case time.Duration: r.DERPLatency[k] = v case int: r.DERPLatency[k] = time.Second * time.Duration(v) default: panic(fmt.Sprintf("unexpected type %T", v)) } } return r } type step struct { after time.Duration r *Report } tests := []struct { name string steps []step wantDERP int // want PreferredDERP on final step wantPrevLen int // wanted len(c.prev) }{ { name: "first_reading", steps: []step{ {0, report("d1", 2, "d2", 3)}, }, wantPrevLen: 1, wantDERP: 1, }, { name: "with_two", steps: []step{ {0, report("d1", 2, "d2", 3)}, {1 * time.Second, report("d1", 4, "d2", 3)}, }, wantPrevLen: 2, wantDERP: 1, // t0's d1 of 2 is still best }, { name: "but_now_d1_gone", steps: []step{ {0, report("d1", 2, "d2", 3)}, {1 * time.Second, report("d1", 4, "d2", 3)}, {2 * time.Second, report("d2", 3)}, }, wantPrevLen: 3, wantDERP: 2, // only option }, { name: "d1_is_back", steps: []step{ {0, report("d1", 2, "d2", 3)}, {1 * time.Second, report("d1", 4, "d2", 3)}, {2 * time.Second, report("d2", 3)}, {3 * time.Second, report("d1", 4, "d2", 3)}, // same as 2 seconds ago }, wantPrevLen: 4, wantDERP: 1, // t0's d1 of 2 is still best }, { name: "things_clean_up", steps: []step{ {0, report("d1", 1, "d2", 2)}, {1 * time.Second, report("d1", 1, "d2", 2)}, {2 * time.Second, report("d1", 1, "d2", 2)}, {3 * time.Second, report("d1", 1, "d2", 2)}, {10 * time.Minute, report("d3", 3)}, }, wantPrevLen: 1, // t=[0123]s all gone. (too old, older than 10 min) wantDERP: 3, // only option }, } for _, tt := range tests { t.Run(tt.name, func(t *testing.T) { fakeTime := time.Unix(123, 0) c := &Client{ DERP: derps, TimeNow: func() time.Time { return fakeTime }, } for _, s := range tt.steps { fakeTime = fakeTime.Add(s.after) c.addReportHistoryAndSetPreferredDERP(s.r) } lastReport := tt.steps[len(tt.steps)-1].r if got, want := len(c.prev), tt.wantPrevLen; got != want { t.Errorf("len(prev) = %v; want %v", got, want) } if got, want := lastReport.PreferredDERP, tt.wantDERP; got != want { t.Errorf("PreferredDERP = %v; want %v", got, want) } }) } }