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tailscale/net/netcheck/netcheck_test.go

721 lines
18 KiB
Go

// Copyright (c) Tailscale Inc & AUTHORS
// SPDX-License-Identifier: BSD-3-Clause
package netcheck
import (
"bytes"
"context"
"fmt"
"net"
"net/http"
"net/netip"
"reflect"
"sort"
"strconv"
"strings"
"sync/atomic"
"testing"
"time"
"tailscale.com/net/interfaces"
"tailscale.com/net/stun"
"tailscale.com/net/stun/stuntest"
"tailscale.com/tailcfg"
)
func TestHairpinSTUN(t *testing.T) {
tx := stun.NewTxID()
c := &Client{
curState: &reportState{
hairTX: tx,
gotHairSTUN: make(chan netip.AddrPort, 1),
},
}
req := stun.Request(tx)
if !stun.Is(req) {
t.Fatal("expected STUN message")
}
if !c.handleHairSTUNLocked(req, netip.AddrPort{}) {
t.Fatal("expected true")
}
select {
case <-c.curState.gotHairSTUN:
default:
t.Fatal("expected value")
}
}
func TestBasic(t *testing.T) {
stunAddr, cleanup := stuntest.Serve(t)
defer cleanup()
c := &Client{
Logf: t.Logf,
UDPBindAddr: "127.0.0.1:0",
}
ctx, cancel := context.WithTimeout(context.Background(), 1*time.Second)
defer cancel()
r, err := c.GetReport(ctx, stuntest.DERPMapOf(stunAddr.String()))
if err != nil {
t.Fatal(err)
}
if !r.UDP {
t.Error("want UDP")
}
if len(r.RegionLatency) != 1 {
t.Errorf("expected 1 key in DERPLatency; got %+v", r.RegionLatency)
}
if _, ok := r.RegionLatency[1]; !ok {
t.Errorf("expected key 1 in DERPLatency; got %+v", r.RegionLatency)
}
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()
dm := stuntest.DERPMapOf(stunAddr)
dm.Regions[1].Nodes[0].STUNOnly = true
c := &Client{
Logf: t.Logf,
}
ctx, cancel := context.WithTimeout(context.Background(), 250*time.Millisecond)
defer cancel()
r, err := c.GetReport(ctx, dm)
if err != nil {
t.Fatal(err)
}
r.UPnP = ""
r.PMP = ""
r.PCP = ""
want := newReport()
// The IPv4CanSend flag gets set differently across platforms.
// On Windows this test detects false, while on Linux detects true.
// That's not relevant to this test, so just accept what we're
// given.
want.IPv4CanSend = r.IPv4CanSend
// OS IPv6 test is irrelevant here, accept whatever the current
// machine has.
want.OSHasIPv6 = r.OSHasIPv6
// Captive portal test is irrelevant; accept what the current report
// has.
want.CaptivePortal = r.CaptivePortal
if !reflect.DeepEqual(r, want) {
t.Errorf("mismatch\n got: %+v\nwant: %+v\n", r, want)
}
}
func TestAddReportHistoryAndSetPreferredDERP(t *testing.T) {
// report returns a *Report from (DERP host, time.Duration)+ pairs.
report := func(a ...any) *Report {
r := &Report{RegionLatency: map[int]time.Duration{}}
for i := 0; i < len(a); i += 2 {
s := a[i].(string)
if !strings.HasPrefix(s, "d") {
t.Fatalf("invalid derp server key %q", s)
}
regionID, err := strconv.Atoi(s[1:])
if err != nil {
t.Fatalf("invalid derp server key %q", s)
}
switch v := a[i+1].(type) {
case time.Duration:
r.RegionLatency[regionID] = v
case int:
r.RegionLatency[regionID] = 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
},
{
name: "preferred_derp_hysteresis_no_switch",
steps: []step{
{0 * time.Second, report("d1", 4, "d2", 5)},
{1 * time.Second, report("d1", 4, "d2", 3)},
},
wantPrevLen: 2,
wantDERP: 1, // 2 didn't get fast enough
},
{
name: "preferred_derp_hysteresis_do_switch",
steps: []step{
{0 * time.Second, report("d1", 4, "d2", 5)},
{1 * time.Second, report("d1", 4, "d2", 1)},
},
wantPrevLen: 2,
wantDERP: 2, // 2 got fast enough
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
fakeTime := time.Unix(123, 0)
c := &Client{
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)
}
})
}
}
func TestMakeProbePlan(t *testing.T) {
// basicMap has 5 regions. each region has a number of nodes
// equal to the region number (1 has 1a, 2 has 2a and 2b, etc.)
basicMap := &tailcfg.DERPMap{
Regions: map[int]*tailcfg.DERPRegion{},
}
for rid := 1; rid <= 5; rid++ {
var nodes []*tailcfg.DERPNode
for nid := 0; nid < rid; nid++ {
nodes = append(nodes, &tailcfg.DERPNode{
Name: fmt.Sprintf("%d%c", rid, 'a'+rune(nid)),
RegionID: rid,
HostName: fmt.Sprintf("derp%d-%d", rid, nid),
IPv4: fmt.Sprintf("%d.0.0.%d", rid, nid),
IPv6: fmt.Sprintf("%d::%d", rid, nid),
})
}
basicMap.Regions[rid] = &tailcfg.DERPRegion{
RegionID: rid,
Nodes: nodes,
}
}
const ms = time.Millisecond
p := func(name string, c rune, d ...time.Duration) probe {
var proto probeProto
switch c {
case 4:
proto = probeIPv4
case 6:
proto = probeIPv6
case 'h':
proto = probeHTTPS
}
pr := probe{node: name, proto: proto}
if len(d) == 1 {
pr.delay = d[0]
} else if len(d) > 1 {
panic("too many args")
}
return pr
}
tests := []struct {
name string
dm *tailcfg.DERPMap
have6if bool
no4 bool // no IPv4
last *Report
want probePlan
}{
{
name: "initial_v6",
dm: basicMap,
have6if: true,
last: nil, // initial
want: probePlan{
"region-1-v4": []probe{p("1a", 4), p("1a", 4, 100*ms), p("1a", 4, 200*ms)}, // all a
"region-1-v6": []probe{p("1a", 6), p("1a", 6, 100*ms), p("1a", 6, 200*ms)},
"region-2-v4": []probe{p("2a", 4), p("2b", 4, 100*ms), p("2a", 4, 200*ms)}, // a -> b -> a
"region-2-v6": []probe{p("2a", 6), p("2b", 6, 100*ms), p("2a", 6, 200*ms)},
"region-3-v4": []probe{p("3a", 4), p("3b", 4, 100*ms), p("3c", 4, 200*ms)}, // a -> b -> c
"region-3-v6": []probe{p("3a", 6), p("3b", 6, 100*ms), p("3c", 6, 200*ms)},
"region-4-v4": []probe{p("4a", 4), p("4b", 4, 100*ms), p("4c", 4, 200*ms)},
"region-4-v6": []probe{p("4a", 6), p("4b", 6, 100*ms), p("4c", 6, 200*ms)},
"region-5-v4": []probe{p("5a", 4), p("5b", 4, 100*ms), p("5c", 4, 200*ms)},
"region-5-v6": []probe{p("5a", 6), p("5b", 6, 100*ms), p("5c", 6, 200*ms)},
},
},
{
name: "initial_no_v6",
dm: basicMap,
have6if: false,
last: nil, // initial
want: probePlan{
"region-1-v4": []probe{p("1a", 4), p("1a", 4, 100*ms), p("1a", 4, 200*ms)}, // all a
"region-2-v4": []probe{p("2a", 4), p("2b", 4, 100*ms), p("2a", 4, 200*ms)}, // a -> b -> a
"region-3-v4": []probe{p("3a", 4), p("3b", 4, 100*ms), p("3c", 4, 200*ms)}, // a -> b -> c
"region-4-v4": []probe{p("4a", 4), p("4b", 4, 100*ms), p("4c", 4, 200*ms)},
"region-5-v4": []probe{p("5a", 4), p("5b", 4, 100*ms), p("5c", 4, 200*ms)},
},
},
{
name: "second_v4_no_6if",
dm: basicMap,
have6if: false,
last: &Report{
RegionLatency: map[int]time.Duration{
1: 10 * time.Millisecond,
2: 20 * time.Millisecond,
3: 30 * time.Millisecond,
4: 40 * time.Millisecond,
// Pretend 5 is missing
},
RegionV4Latency: map[int]time.Duration{
1: 10 * time.Millisecond,
2: 20 * time.Millisecond,
3: 30 * time.Millisecond,
4: 40 * time.Millisecond,
},
},
want: probePlan{
"region-1-v4": []probe{p("1a", 4), p("1a", 4, 12*ms)},
"region-2-v4": []probe{p("2a", 4), p("2b", 4, 24*ms)},
"region-3-v4": []probe{p("3a", 4)},
},
},
{
name: "second_v4_only_with_6if",
dm: basicMap,
have6if: true,
last: &Report{
RegionLatency: map[int]time.Duration{
1: 10 * time.Millisecond,
2: 20 * time.Millisecond,
3: 30 * time.Millisecond,
4: 40 * time.Millisecond,
// Pretend 5 is missing
},
RegionV4Latency: map[int]time.Duration{
1: 10 * time.Millisecond,
2: 20 * time.Millisecond,
3: 30 * time.Millisecond,
4: 40 * time.Millisecond,
},
},
want: probePlan{
"region-1-v4": []probe{p("1a", 4), p("1a", 4, 12*ms)},
"region-1-v6": []probe{p("1a", 6)},
"region-2-v4": []probe{p("2a", 4), p("2b", 4, 24*ms)},
"region-2-v6": []probe{p("2a", 6)},
"region-3-v4": []probe{p("3a", 4)},
},
},
{
name: "second_mixed",
dm: basicMap,
have6if: true,
last: &Report{
RegionLatency: map[int]time.Duration{
1: 10 * time.Millisecond,
2: 20 * time.Millisecond,
3: 30 * time.Millisecond,
4: 40 * time.Millisecond,
// Pretend 5 is missing
},
RegionV4Latency: map[int]time.Duration{
1: 10 * time.Millisecond,
2: 20 * time.Millisecond,
},
RegionV6Latency: map[int]time.Duration{
3: 30 * time.Millisecond,
4: 40 * time.Millisecond,
},
},
want: probePlan{
"region-1-v4": []probe{p("1a", 4), p("1a", 4, 12*ms)},
"region-1-v6": []probe{p("1a", 6), p("1a", 6, 12*ms)},
"region-2-v4": []probe{p("2a", 4), p("2b", 4, 24*ms)},
"region-2-v6": []probe{p("2a", 6), p("2b", 6, 24*ms)},
"region-3-v4": []probe{p("3a", 4)},
},
},
{
name: "only_v6_initial",
have6if: true,
no4: true,
dm: basicMap,
want: probePlan{
"region-1-v6": []probe{p("1a", 6), p("1a", 6, 100*ms), p("1a", 6, 200*ms)},
"region-2-v6": []probe{p("2a", 6), p("2b", 6, 100*ms), p("2a", 6, 200*ms)},
"region-3-v6": []probe{p("3a", 6), p("3b", 6, 100*ms), p("3c", 6, 200*ms)},
"region-4-v6": []probe{p("4a", 6), p("4b", 6, 100*ms), p("4c", 6, 200*ms)},
"region-5-v6": []probe{p("5a", 6), p("5b", 6, 100*ms), p("5c", 6, 200*ms)},
},
},
{
name: "try_harder_for_preferred_derp",
dm: basicMap,
have6if: true,
last: &Report{
RegionLatency: map[int]time.Duration{
1: 10 * time.Millisecond,
2: 20 * time.Millisecond,
3: 30 * time.Millisecond,
4: 40 * time.Millisecond,
},
RegionV4Latency: map[int]time.Duration{
1: 10 * time.Millisecond,
2: 20 * time.Millisecond,
},
RegionV6Latency: map[int]time.Duration{
3: 30 * time.Millisecond,
4: 40 * time.Millisecond,
},
PreferredDERP: 1,
},
want: probePlan{
"region-1-v4": []probe{p("1a", 4), p("1a", 4, 12*ms), p("1a", 4, 124*ms), p("1a", 4, 186*ms)},
"region-1-v6": []probe{p("1a", 6), p("1a", 6, 12*ms), p("1a", 6, 124*ms), p("1a", 6, 186*ms)},
"region-2-v4": []probe{p("2a", 4), p("2b", 4, 24*ms)},
"region-2-v6": []probe{p("2a", 6), p("2b", 6, 24*ms)},
"region-3-v4": []probe{p("3a", 4)},
},
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
ifState := &interfaces.State{
HaveV6: tt.have6if,
HaveV4: !tt.no4,
}
got := makeProbePlan(tt.dm, ifState, tt.last)
if !reflect.DeepEqual(got, tt.want) {
t.Errorf("unexpected plan; got:\n%v\nwant:\n%v\n", got, tt.want)
}
})
}
}
func (plan probePlan) String() string {
var sb strings.Builder
keys := []string{}
for k := range plan {
keys = append(keys, k)
}
sort.Strings(keys)
for _, key := range keys {
fmt.Fprintf(&sb, "[%s]", key)
pv := plan[key]
for _, p := range pv {
fmt.Fprintf(&sb, " %v", p)
}
sb.WriteByte('\n')
}
return sb.String()
}
func (p probe) String() string {
wait := ""
if p.wait > 0 {
wait = "+" + p.wait.String()
}
delay := ""
if p.delay > 0 {
delay = "@" + p.delay.String()
}
return fmt.Sprintf("%s-%s%s%s", p.node, p.proto, delay, wait)
}
func (p probeProto) String() string {
switch p {
case probeIPv4:
return "v4"
case probeIPv6:
return "v4"
case probeHTTPS:
return "https"
}
return "?"
}
func TestLogConciseReport(t *testing.T) {
dm := &tailcfg.DERPMap{
Regions: map[int]*tailcfg.DERPRegion{
1: nil,
2: nil,
3: nil,
},
}
const ms = time.Millisecond
tests := []struct {
name string
r *Report
want string
}{
{
name: "no_udp",
r: &Report{},
want: "udp=false v4=false icmpv4=false v6=false mapvarydest= hair= portmap=? derp=0",
},
{
name: "no_udp_icmp",
r: &Report{ICMPv4: true, IPv4: true},
want: "udp=false icmpv4=true v6=false mapvarydest= hair= portmap=? derp=0",
},
{
name: "ipv4_one_region",
r: &Report{
UDP: true,
IPv4: true,
PreferredDERP: 1,
RegionLatency: map[int]time.Duration{
1: 10 * ms,
},
RegionV4Latency: map[int]time.Duration{
1: 10 * ms,
},
},
want: "udp=true v6=false mapvarydest= hair= portmap=? derp=1 derpdist=1v4:10ms",
},
{
name: "ipv4_all_region",
r: &Report{
UDP: true,
IPv4: true,
PreferredDERP: 1,
RegionLatency: map[int]time.Duration{
1: 10 * ms,
2: 20 * ms,
3: 30 * ms,
},
RegionV4Latency: map[int]time.Duration{
1: 10 * ms,
2: 20 * ms,
3: 30 * ms,
},
},
want: "udp=true v6=false mapvarydest= hair= portmap=? derp=1 derpdist=1v4:10ms,2v4:20ms,3v4:30ms",
},
{
name: "ipboth_all_region",
r: &Report{
UDP: true,
IPv4: true,
IPv6: true,
PreferredDERP: 1,
RegionLatency: map[int]time.Duration{
1: 10 * ms,
2: 20 * ms,
3: 30 * ms,
},
RegionV4Latency: map[int]time.Duration{
1: 10 * ms,
2: 20 * ms,
3: 30 * ms,
},
RegionV6Latency: map[int]time.Duration{
1: 10 * ms,
2: 20 * ms,
3: 30 * ms,
},
},
want: "udp=true v6=true mapvarydest= hair= portmap=? derp=1 derpdist=1v4:10ms,1v6:10ms,2v4:20ms,2v6:20ms,3v4:30ms,3v6:30ms",
},
{
name: "portmap_all",
r: &Report{
UDP: true,
UPnP: "true",
PMP: "true",
PCP: "true",
},
want: "udp=true v4=false v6=false mapvarydest= hair= portmap=UMC derp=0",
},
{
name: "portmap_some",
r: &Report{
UDP: true,
UPnP: "true",
PMP: "false",
PCP: "true",
},
want: "udp=true v4=false v6=false mapvarydest= hair= portmap=UC derp=0",
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
var buf bytes.Buffer
c := &Client{Logf: func(f string, a ...any) { fmt.Fprintf(&buf, f, a...) }}
c.logConciseReport(tt.r, dm)
if got, ok := strings.CutPrefix(buf.String(), "[v1] report: "); !ok {
t.Errorf("unexpected result.\n got: %#q\nwant: %#q\n", got, tt.want)
}
})
}
}
func TestSortRegions(t *testing.T) {
unsortedMap := &tailcfg.DERPMap{
Regions: map[int]*tailcfg.DERPRegion{},
}
for rid := 1; rid <= 5; rid++ {
var nodes []*tailcfg.DERPNode
nodes = append(nodes, &tailcfg.DERPNode{
Name: fmt.Sprintf("%da", rid),
RegionID: rid,
HostName: fmt.Sprintf("derp%d-1", rid),
IPv4: fmt.Sprintf("%d.0.0.1", rid),
IPv6: fmt.Sprintf("%d::1", rid),
})
unsortedMap.Regions[rid] = &tailcfg.DERPRegion{
RegionID: rid,
Nodes: nodes,
}
}
report := newReport()
report.RegionLatency[1] = time.Second * time.Duration(5)
report.RegionLatency[2] = time.Second * time.Duration(3)
report.RegionLatency[3] = time.Second * time.Duration(6)
report.RegionLatency[4] = time.Second * time.Duration(0)
report.RegionLatency[5] = time.Second * time.Duration(2)
sortedMap := sortRegions(unsortedMap, report)
// Sorting by latency this should result in rid: 5, 2, 1, 3
// rid 4 with latency 0 should be at the end
want := []int{5, 2, 1, 3, 4}
got := make([]int, len(sortedMap))
for i, r := range sortedMap {
got[i] = r.RegionID
}
if !reflect.DeepEqual(got, want) {
t.Errorf("got %v; want %v", got, want)
}
}
func TestNoCaptivePortalWhenUDP(t *testing.T) {
// Override noRedirectClient to handle the /generate_204 endpoint
var generate204Called atomic.Bool
tr := RoundTripFunc(func(req *http.Request) *http.Response {
if !strings.HasSuffix(req.URL.String(), "/generate_204") {
panic("bad URL: " + req.URL.String())
}
generate204Called.Store(true)
return &http.Response{
StatusCode: http.StatusNoContent,
Header: make(http.Header),
}
})
oldTransport := noRedirectClient.Transport
t.Cleanup(func() { noRedirectClient.Transport = oldTransport })
noRedirectClient.Transport = tr
stunAddr, cleanup := stuntest.Serve(t)
defer cleanup()
c := &Client{
Logf: t.Logf,
UDPBindAddr: "127.0.0.1:0",
testEnoughRegions: 1,
// Set the delay long enough that we have time to cancel it
// when our STUN probe succeeds.
testCaptivePortalDelay: 10 * time.Second,
}
ctx, cancel := context.WithTimeout(context.Background(), 1*time.Second)
defer cancel()
r, err := c.GetReport(ctx, stuntest.DERPMapOf(stunAddr.String()))
if err != nil {
t.Fatal(err)
}
// Should not have called our captive portal function.
if generate204Called.Load() {
t.Errorf("captive portal check called; expected no call")
}
if r.CaptivePortal != "" {
t.Errorf("got CaptivePortal=%q, want empty", r.CaptivePortal)
}
}
type RoundTripFunc func(req *http.Request) *http.Response
func (f RoundTripFunc) RoundTrip(req *http.Request) (*http.Response, error) {
return f(req), nil
}