appc: unadvertise routes when reconfiguring app connector

If the controlknob to persist app connector routes is enabled, when
reconfiguring an app connector unadvertise routes that are no longer
relevant.

Updates #11008
Signed-off-by: Fran Bull <fran@tailscale.com>
This commit is contained in:
Fran Bull 2024-04-15 10:16:02 -07:00
parent 63f66ad4ad
commit fd096680f0
2 changed files with 205 additions and 2 deletions

View File

@ -23,6 +23,7 @@ import (
"tailscale.com/util/dnsname"
"tailscale.com/util/execqueue"
"tailscale.com/util/mak"
"tailscale.com/util/slicesx"
)
// RouteAdvertiser is an interface that allows the AppConnector to advertise
@ -166,10 +167,26 @@ func (e *AppConnector) updateDomains(domains []string) {
for _, wc := range e.wildcards {
if dnsname.HasSuffix(d, wc) {
e.domains[d] = addrs
delete(oldDomains, d)
break
}
}
}
// Everything left in oldDomains is a domain we're no longer tracking
// and if we are storing route info we can unadvertise the routes
if e.ShouldStoreRoutes() {
toRemove := []netip.Prefix{}
for _, addrs := range oldDomains {
for _, a := range addrs {
toRemove = append(toRemove, netip.PrefixFrom(a, a.BitLen()))
}
}
if err := e.routeAdvertiser.UnadvertiseRoute(toRemove...); err != nil {
e.logf("failed to unadvertise routes on domain removal: %v: %v: %v", xmaps.Keys(oldDomains), toRemove, err)
}
}
e.logf("handling domains: %v and wildcards: %v", xmaps.Keys(e.domains), e.wildcards)
}
@ -193,6 +210,14 @@ func (e *AppConnector) updateRoutes(routes []netip.Prefix) {
var toRemove []netip.Prefix
// If we're storing routes and know e.controlRoutes is a good
// representation of what should be in AdvertisedRoutes we can stop
// advertising routes that used to be in e.controlRoutes but are not
// in routes.
if e.ShouldStoreRoutes() {
toRemove = routesWithout(e.controlRoutes, routes)
}
nextRoute:
for _, r := range routes {
for _, addr := range e.domains {
@ -447,3 +472,15 @@ func (e *AppConnector) addDomainAddrLocked(domain string, addr netip.Addr) {
func compareAddr(l, r netip.Addr) int {
return l.Compare(r)
}
// routesWithout returns a without b where a and b
// are unsorted slices of netip.Prefix
func routesWithout(a, b []netip.Prefix) []netip.Prefix {
m := make(map[netip.Prefix]bool, len(b))
for _, p := range b {
m[p] = true
}
return slicesx.Filter(make([]netip.Prefix, 0, len(a)), a, func(p netip.Prefix) bool {
return !m[p]
})
}

View File

@ -24,9 +24,9 @@ func TestUpdateDomains(t *testing.T) {
ctx := context.Background()
var a *AppConnector
if shouldStore {
a = NewAppConnector(t.Logf, nil, &RouteInfo{}, fakeStoreRoutes)
a = NewAppConnector(t.Logf, &appctest.RouteCollector{}, &RouteInfo{}, fakeStoreRoutes)
} else {
a = NewAppConnector(t.Logf, nil, nil, nil)
a = NewAppConnector(t.Logf, &appctest.RouteCollector{}, nil, nil)
}
a.UpdateDomains([]string{"example.com"})
@ -354,3 +354,169 @@ func prefixCompare(a, b netip.Prefix) int {
}
return a.Addr().Compare(b.Addr())
}
func prefixes(in ...string) []netip.Prefix {
toRet := make([]netip.Prefix, len(in))
for i, s := range in {
toRet[i] = netip.MustParsePrefix(s)
}
return toRet
}
func TestUpdateRouteRouteRemoval(t *testing.T) {
for _, shouldStore := range []bool{false, true} {
ctx := context.Background()
rc := &appctest.RouteCollector{}
assertRoutes := func(prefix string, routes, removedRoutes []netip.Prefix) {
if !slices.Equal(routes, rc.Routes()) {
t.Fatalf("%s: (shouldStore=%t) routes want %v, got %v", prefix, shouldStore, routes, rc.Routes())
}
if !slices.Equal(removedRoutes, rc.RemovedRoutes()) {
t.Fatalf("%s: (shouldStore=%t) removedRoutes want %v, got %v", prefix, shouldStore, removedRoutes, rc.RemovedRoutes())
}
}
var a *AppConnector
if shouldStore {
a = NewAppConnector(t.Logf, rc, &RouteInfo{}, fakeStoreRoutes)
} else {
a = NewAppConnector(t.Logf, rc, nil, nil)
}
// nothing has yet been advertised
assertRoutes("appc init", []netip.Prefix{}, []netip.Prefix{})
a.UpdateDomainsAndRoutes([]string{}, prefixes("1.2.3.1/32", "1.2.3.2/32"))
a.Wait(ctx)
// the routes passed to UpdateDomainsAndRoutes have been advertised
assertRoutes("simple update", prefixes("1.2.3.1/32", "1.2.3.2/32"), []netip.Prefix{})
// one route the same, one different
a.UpdateDomainsAndRoutes([]string{}, prefixes("1.2.3.1/32", "1.2.3.3/32"))
a.Wait(ctx)
// old behavior: routes are not removed, resulting routes are both old and new
// (we have dupe 1.2.3.1 routes because the test RouteAdvertiser doesn't have the deduplication
// the real one does)
wantRoutes := prefixes("1.2.3.1/32", "1.2.3.2/32", "1.2.3.1/32", "1.2.3.3/32")
wantRemovedRoutes := []netip.Prefix{}
if shouldStore {
// new behavior: routes are removed, resulting routes are new only
wantRoutes = prefixes("1.2.3.1/32", "1.2.3.1/32", "1.2.3.3/32")
wantRemovedRoutes = prefixes("1.2.3.2/32")
}
assertRoutes("removal", wantRoutes, wantRemovedRoutes)
}
}
func TestUpdateDomainRouteRemoval(t *testing.T) {
for _, shouldStore := range []bool{false, true} {
ctx := context.Background()
rc := &appctest.RouteCollector{}
assertRoutes := func(prefix string, routes, removedRoutes []netip.Prefix) {
if !slices.Equal(routes, rc.Routes()) {
t.Fatalf("%s: (shouldStore=%t) routes want %v, got %v", prefix, shouldStore, routes, rc.Routes())
}
if !slices.Equal(removedRoutes, rc.RemovedRoutes()) {
t.Fatalf("%s: (shouldStore=%t) removedRoutes want %v, got %v", prefix, shouldStore, removedRoutes, rc.RemovedRoutes())
}
}
var a *AppConnector
if shouldStore {
a = NewAppConnector(t.Logf, rc, &RouteInfo{}, fakeStoreRoutes)
} else {
a = NewAppConnector(t.Logf, rc, nil, nil)
}
assertRoutes("appc init", []netip.Prefix{}, []netip.Prefix{})
a.UpdateDomainsAndRoutes([]string{"a.example.com", "b.example.com"}, []netip.Prefix{})
a.Wait(ctx)
// adding domains doesn't immediately cause any routes to be advertised
assertRoutes("update domains", []netip.Prefix{}, []netip.Prefix{})
a.ObserveDNSResponse(dnsResponse("a.example.com.", "1.2.3.1"))
a.ObserveDNSResponse(dnsResponse("a.example.com.", "1.2.3.2"))
a.ObserveDNSResponse(dnsResponse("b.example.com.", "1.2.3.3"))
a.ObserveDNSResponse(dnsResponse("b.example.com.", "1.2.3.4"))
a.Wait(ctx)
// observing dns responses causes routes to be advertised
assertRoutes("observed dns", prefixes("1.2.3.1/32", "1.2.3.2/32", "1.2.3.3/32", "1.2.3.4/32"), []netip.Prefix{})
a.UpdateDomainsAndRoutes([]string{"a.example.com"}, []netip.Prefix{})
a.Wait(ctx)
// old behavior, routes are not removed
wantRoutes := prefixes("1.2.3.1/32", "1.2.3.2/32", "1.2.3.3/32", "1.2.3.4/32")
wantRemovedRoutes := []netip.Prefix{}
if shouldStore {
// new behavior, routes are removed for b.example.com
wantRoutes = prefixes("1.2.3.1/32", "1.2.3.2/32")
wantRemovedRoutes = prefixes("1.2.3.3/32", "1.2.3.4/32")
}
assertRoutes("removal", wantRoutes, wantRemovedRoutes)
}
}
func TestUpdateWildcardRouteRemoval(t *testing.T) {
for _, shouldStore := range []bool{false, true} {
ctx := context.Background()
rc := &appctest.RouteCollector{}
assertRoutes := func(prefix string, routes, removedRoutes []netip.Prefix) {
if !slices.Equal(routes, rc.Routes()) {
t.Fatalf("%s: (shouldStore=%t) routes want %v, got %v", prefix, shouldStore, routes, rc.Routes())
}
if !slices.Equal(removedRoutes, rc.RemovedRoutes()) {
t.Fatalf("%s: (shouldStore=%t) removedRoutes want %v, got %v", prefix, shouldStore, removedRoutes, rc.RemovedRoutes())
}
}
var a *AppConnector
if shouldStore {
a = NewAppConnector(t.Logf, rc, &RouteInfo{}, fakeStoreRoutes)
} else {
a = NewAppConnector(t.Logf, rc, nil, nil)
}
assertRoutes("appc init", []netip.Prefix{}, []netip.Prefix{})
a.UpdateDomainsAndRoutes([]string{"a.example.com", "*.b.example.com"}, []netip.Prefix{})
a.Wait(ctx)
// adding domains doesn't immediately cause any routes to be advertised
assertRoutes("update domains", []netip.Prefix{}, []netip.Prefix{})
a.ObserveDNSResponse(dnsResponse("a.example.com.", "1.2.3.1"))
a.ObserveDNSResponse(dnsResponse("a.example.com.", "1.2.3.2"))
a.ObserveDNSResponse(dnsResponse("1.b.example.com.", "1.2.3.3"))
a.ObserveDNSResponse(dnsResponse("2.b.example.com.", "1.2.3.4"))
a.Wait(ctx)
// observing dns responses causes routes to be advertised
assertRoutes("observed dns", prefixes("1.2.3.1/32", "1.2.3.2/32", "1.2.3.3/32", "1.2.3.4/32"), []netip.Prefix{})
a.UpdateDomainsAndRoutes([]string{"a.example.com"}, []netip.Prefix{})
a.Wait(ctx)
// old behavior, routes are not removed
wantRoutes := prefixes("1.2.3.1/32", "1.2.3.2/32", "1.2.3.3/32", "1.2.3.4/32")
wantRemovedRoutes := []netip.Prefix{}
if shouldStore {
// new behavior, routes are removed for *.b.example.com
wantRoutes = prefixes("1.2.3.1/32", "1.2.3.2/32")
wantRemovedRoutes = prefixes("1.2.3.3/32", "1.2.3.4/32")
}
assertRoutes("removal", wantRoutes, wantRemovedRoutes)
}
}
func TestRoutesWithout(t *testing.T) {
assert := func(msg string, got, want []netip.Prefix) {
if !slices.Equal(want, got) {
t.Errorf("%s: want %v, got %v", msg, want, got)
}
}
assert("empty routes", routesWithout([]netip.Prefix{}, []netip.Prefix{}), []netip.Prefix{})
assert("a empty", routesWithout([]netip.Prefix{}, prefixes("1.1.1.1/32", "1.1.1.2/32")), []netip.Prefix{})
assert("b empty", routesWithout(prefixes("1.1.1.1/32", "1.1.1.2/32"), []netip.Prefix{}), prefixes("1.1.1.1/32", "1.1.1.2/32"))
assert("no overlap", routesWithout(prefixes("1.1.1.1/32", "1.1.1.2/32"), prefixes("1.1.1.3/32", "1.1.1.4/32")), prefixes("1.1.1.1/32", "1.1.1.2/32"))
assert("a has fewer", routesWithout(prefixes("1.1.1.1/32", "1.1.1.2/32"), prefixes("1.1.1.1/32", "1.1.1.2/32", "1.1.1.3/32", "1.1.1.4/32")), []netip.Prefix{})
assert("a has more", routesWithout(prefixes("1.1.1.1/32", "1.1.1.2/32", "1.1.1.3/32", "1.1.1.4/32"), prefixes("1.1.1.1/32", "1.1.1.3/32")), prefixes("1.1.1.2/32", "1.1.1.4/32"))
}