tailscale/appc/appconnector_test.go
Fran Bull 1bd1b387b2 appc: add flag shouldStoreRoutes and controlknob for it
When an app connector is reconfigured and domains to route are removed,
we would like to no longer advertise routes that were discovered for
those domains. In order to do this we plan to store which routes were
discovered for which domains.

Add a controlknob so that we can enable/disable the new behavior.

Updates #11008
Signed-off-by: Fran Bull <fran@tailscale.com>
2024-04-29 11:40:04 -07:00

357 lines
11 KiB
Go

// Copyright (c) Tailscale Inc & AUTHORS
// SPDX-License-Identifier: BSD-3-Clause
package appc
import (
"context"
"net/netip"
"reflect"
"slices"
"testing"
xmaps "golang.org/x/exp/maps"
"golang.org/x/net/dns/dnsmessage"
"tailscale.com/appc/appctest"
"tailscale.com/util/mak"
"tailscale.com/util/must"
)
func fakeStoreRoutes(*RouteInfo) error { return nil }
func TestUpdateDomains(t *testing.T) {
for _, shouldStore := range []bool{false, true} {
ctx := context.Background()
var a *AppConnector
if shouldStore {
a = NewAppConnector(t.Logf, nil, &RouteInfo{}, fakeStoreRoutes)
} else {
a = NewAppConnector(t.Logf, nil, nil, nil)
}
a.UpdateDomains([]string{"example.com"})
a.Wait(ctx)
if got, want := a.Domains().AsSlice(), []string{"example.com"}; !slices.Equal(got, want) {
t.Errorf("got %v; want %v", got, want)
}
addr := netip.MustParseAddr("192.0.0.8")
a.domains["example.com"] = append(a.domains["example.com"], addr)
a.UpdateDomains([]string{"example.com"})
a.Wait(ctx)
if got, want := a.domains["example.com"], []netip.Addr{addr}; !slices.Equal(got, want) {
t.Errorf("got %v; want %v", got, want)
}
// domains are explicitly downcased on set.
a.UpdateDomains([]string{"UP.EXAMPLE.COM"})
a.Wait(ctx)
if got, want := xmaps.Keys(a.domains), []string{"up.example.com"}; !slices.Equal(got, want) {
t.Errorf("got %v; want %v", got, want)
}
}
}
func TestUpdateRoutes(t *testing.T) {
for _, shouldStore := range []bool{false, true} {
ctx := context.Background()
rc := &appctest.RouteCollector{}
var a *AppConnector
if shouldStore {
a = NewAppConnector(t.Logf, rc, &RouteInfo{}, fakeStoreRoutes)
} else {
a = NewAppConnector(t.Logf, rc, nil, nil)
}
a.updateDomains([]string{"*.example.com"})
// This route should be collapsed into the range
a.ObserveDNSResponse(dnsResponse("a.example.com.", "192.0.2.1"))
a.Wait(ctx)
if !slices.Equal(rc.Routes(), []netip.Prefix{netip.MustParsePrefix("192.0.2.1/32")}) {
t.Fatalf("got %v, want %v", rc.Routes(), []netip.Prefix{netip.MustParsePrefix("192.0.2.1/32")})
}
// This route should not be collapsed or removed
a.ObserveDNSResponse(dnsResponse("b.example.com.", "192.0.0.1"))
a.Wait(ctx)
routes := []netip.Prefix{netip.MustParsePrefix("192.0.2.0/24"), netip.MustParsePrefix("192.0.0.1/32")}
a.updateRoutes(routes)
slices.SortFunc(rc.Routes(), prefixCompare)
rc.SetRoutes(slices.Compact(rc.Routes()))
slices.SortFunc(routes, prefixCompare)
// Ensure that the non-matching /32 is preserved, even though it's in the domains table.
if !slices.EqualFunc(routes, rc.Routes(), prefixEqual) {
t.Errorf("added routes: got %v, want %v", rc.Routes(), routes)
}
// Ensure that the contained /32 is removed, replaced by the /24.
wantRemoved := []netip.Prefix{netip.MustParsePrefix("192.0.2.1/32")}
if !slices.EqualFunc(rc.RemovedRoutes(), wantRemoved, prefixEqual) {
t.Fatalf("unexpected removed routes: %v", rc.RemovedRoutes())
}
}
}
func TestUpdateRoutesUnadvertisesContainedRoutes(t *testing.T) {
for _, shouldStore := range []bool{false, true} {
rc := &appctest.RouteCollector{}
var a *AppConnector
if shouldStore {
a = NewAppConnector(t.Logf, rc, &RouteInfo{}, fakeStoreRoutes)
} else {
a = NewAppConnector(t.Logf, rc, nil, nil)
}
mak.Set(&a.domains, "example.com", []netip.Addr{netip.MustParseAddr("192.0.2.1")})
rc.SetRoutes([]netip.Prefix{netip.MustParsePrefix("192.0.2.1/32")})
routes := []netip.Prefix{netip.MustParsePrefix("192.0.2.0/24")}
a.updateRoutes(routes)
if !slices.EqualFunc(routes, rc.Routes(), prefixEqual) {
t.Fatalf("got %v, want %v", rc.Routes(), routes)
}
}
}
func TestDomainRoutes(t *testing.T) {
for _, shouldStore := range []bool{false, true} {
rc := &appctest.RouteCollector{}
var a *AppConnector
if shouldStore {
a = NewAppConnector(t.Logf, rc, &RouteInfo{}, fakeStoreRoutes)
} else {
a = NewAppConnector(t.Logf, rc, nil, nil)
}
a.updateDomains([]string{"example.com"})
a.ObserveDNSResponse(dnsResponse("example.com.", "192.0.0.8"))
a.Wait(context.Background())
want := map[string][]netip.Addr{
"example.com": {netip.MustParseAddr("192.0.0.8")},
}
if got := a.DomainRoutes(); !reflect.DeepEqual(got, want) {
t.Fatalf("DomainRoutes: got %v, want %v", got, want)
}
}
}
func TestObserveDNSResponse(t *testing.T) {
for _, shouldStore := range []bool{false, true} {
ctx := context.Background()
rc := &appctest.RouteCollector{}
var a *AppConnector
if shouldStore {
a = NewAppConnector(t.Logf, rc, &RouteInfo{}, fakeStoreRoutes)
} else {
a = NewAppConnector(t.Logf, rc, nil, nil)
}
// a has no domains configured, so it should not advertise any routes
a.ObserveDNSResponse(dnsResponse("example.com.", "192.0.0.8"))
if got, want := rc.Routes(), ([]netip.Prefix)(nil); !slices.Equal(got, want) {
t.Errorf("got %v; want %v", got, want)
}
wantRoutes := []netip.Prefix{netip.MustParsePrefix("192.0.0.8/32")}
a.updateDomains([]string{"example.com"})
a.ObserveDNSResponse(dnsResponse("example.com.", "192.0.0.8"))
a.Wait(ctx)
if got, want := rc.Routes(), wantRoutes; !slices.Equal(got, want) {
t.Errorf("got %v; want %v", got, want)
}
// a CNAME record chain should result in a route being added if the chain
// matches a routed domain.
a.updateDomains([]string{"www.example.com", "example.com"})
a.ObserveDNSResponse(dnsCNAMEResponse("192.0.0.9", "www.example.com.", "chain.example.com.", "example.com."))
a.Wait(ctx)
wantRoutes = append(wantRoutes, netip.MustParsePrefix("192.0.0.9/32"))
if got, want := rc.Routes(), wantRoutes; !slices.Equal(got, want) {
t.Errorf("got %v; want %v", got, want)
}
// a CNAME record chain should result in a route being added if the chain
// even if only found in the middle of the chain
a.ObserveDNSResponse(dnsCNAMEResponse("192.0.0.10", "outside.example.org.", "www.example.com.", "example.org."))
a.Wait(ctx)
wantRoutes = append(wantRoutes, netip.MustParsePrefix("192.0.0.10/32"))
if got, want := rc.Routes(), wantRoutes; !slices.Equal(got, want) {
t.Errorf("got %v; want %v", got, want)
}
wantRoutes = append(wantRoutes, netip.MustParsePrefix("2001:db8::1/128"))
a.ObserveDNSResponse(dnsResponse("example.com.", "2001:db8::1"))
a.Wait(ctx)
if got, want := rc.Routes(), wantRoutes; !slices.Equal(got, want) {
t.Errorf("got %v; want %v", got, want)
}
// don't re-advertise routes that have already been advertised
a.ObserveDNSResponse(dnsResponse("example.com.", "2001:db8::1"))
a.Wait(ctx)
if !slices.Equal(rc.Routes(), wantRoutes) {
t.Errorf("rc.Routes(): got %v; want %v", rc.Routes(), wantRoutes)
}
// don't advertise addresses that are already in a control provided route
pfx := netip.MustParsePrefix("192.0.2.0/24")
a.updateRoutes([]netip.Prefix{pfx})
wantRoutes = append(wantRoutes, pfx)
a.ObserveDNSResponse(dnsResponse("example.com.", "192.0.2.1"))
a.Wait(ctx)
if !slices.Equal(rc.Routes(), wantRoutes) {
t.Errorf("rc.Routes(): got %v; want %v", rc.Routes(), wantRoutes)
}
if !slices.Contains(a.domains["example.com"], netip.MustParseAddr("192.0.2.1")) {
t.Errorf("missing %v from %v", "192.0.2.1", a.domains["exmaple.com"])
}
}
}
func TestWildcardDomains(t *testing.T) {
for _, shouldStore := range []bool{false, true} {
ctx := context.Background()
rc := &appctest.RouteCollector{}
var a *AppConnector
if shouldStore {
a = NewAppConnector(t.Logf, rc, &RouteInfo{}, fakeStoreRoutes)
} else {
a = NewAppConnector(t.Logf, rc, nil, nil)
}
a.updateDomains([]string{"*.example.com"})
a.ObserveDNSResponse(dnsResponse("foo.example.com.", "192.0.0.8"))
a.Wait(ctx)
if got, want := rc.Routes(), []netip.Prefix{netip.MustParsePrefix("192.0.0.8/32")}; !slices.Equal(got, want) {
t.Errorf("routes: got %v; want %v", got, want)
}
if got, want := a.wildcards, []string{"example.com"}; !slices.Equal(got, want) {
t.Errorf("wildcards: got %v; want %v", got, want)
}
a.updateDomains([]string{"*.example.com", "example.com"})
if _, ok := a.domains["foo.example.com"]; !ok {
t.Errorf("expected foo.example.com to be preserved in domains due to wildcard")
}
if got, want := a.wildcards, []string{"example.com"}; !slices.Equal(got, want) {
t.Errorf("wildcards: got %v; want %v", got, want)
}
// There was an early regression where the wildcard domain was added repeatedly, this guards against that.
a.updateDomains([]string{"*.example.com", "example.com"})
if len(a.wildcards) != 1 {
t.Errorf("expected only one wildcard domain, got %v", a.wildcards)
}
}
}
// dnsResponse is a test helper that creates a DNS response buffer for the given domain and address
func dnsResponse(domain, address string) []byte {
addr := netip.MustParseAddr(address)
b := dnsmessage.NewBuilder(nil, dnsmessage.Header{})
b.EnableCompression()
b.StartAnswers()
switch addr.BitLen() {
case 32:
b.AResource(
dnsmessage.ResourceHeader{
Name: dnsmessage.MustNewName(domain),
Type: dnsmessage.TypeA,
Class: dnsmessage.ClassINET,
TTL: 0,
},
dnsmessage.AResource{
A: addr.As4(),
},
)
case 128:
b.AAAAResource(
dnsmessage.ResourceHeader{
Name: dnsmessage.MustNewName(domain),
Type: dnsmessage.TypeAAAA,
Class: dnsmessage.ClassINET,
TTL: 0,
},
dnsmessage.AAAAResource{
AAAA: addr.As16(),
},
)
default:
panic("invalid address length")
}
return must.Get(b.Finish())
}
func dnsCNAMEResponse(address string, domains ...string) []byte {
addr := netip.MustParseAddr(address)
b := dnsmessage.NewBuilder(nil, dnsmessage.Header{})
b.EnableCompression()
b.StartAnswers()
if len(domains) >= 2 {
for i, domain := range domains[:len(domains)-1] {
b.CNAMEResource(
dnsmessage.ResourceHeader{
Name: dnsmessage.MustNewName(domain),
Type: dnsmessage.TypeCNAME,
Class: dnsmessage.ClassINET,
TTL: 0,
},
dnsmessage.CNAMEResource{
CNAME: dnsmessage.MustNewName(domains[i+1]),
},
)
}
}
domain := domains[len(domains)-1]
switch addr.BitLen() {
case 32:
b.AResource(
dnsmessage.ResourceHeader{
Name: dnsmessage.MustNewName(domain),
Type: dnsmessage.TypeA,
Class: dnsmessage.ClassINET,
TTL: 0,
},
dnsmessage.AResource{
A: addr.As4(),
},
)
case 128:
b.AAAAResource(
dnsmessage.ResourceHeader{
Name: dnsmessage.MustNewName(domain),
Type: dnsmessage.TypeAAAA,
Class: dnsmessage.ClassINET,
TTL: 0,
},
dnsmessage.AAAAResource{
AAAA: addr.As16(),
},
)
default:
panic("invalid address length")
}
return must.Get(b.Finish())
}
func prefixEqual(a, b netip.Prefix) bool {
return a == b
}
func prefixCompare(a, b netip.Prefix) int {
if a.Addr().Compare(b.Addr()) == 0 {
return a.Bits() - b.Bits()
}
return a.Addr().Compare(b.Addr())
}