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-rw-r--r--pkg/tcpip/network/ipv6/ndp.go42
-rw-r--r--pkg/tcpip/stack/ndp_test.go292
2 files changed, 225 insertions, 109 deletions
diff --git a/pkg/tcpip/network/ipv6/ndp.go b/pkg/tcpip/network/ipv6/ndp.go
index 9cd283eba..8837d66d8 100644
--- a/pkg/tcpip/network/ipv6/ndp.go
+++ b/pkg/tcpip/network/ipv6/ndp.go
@@ -54,6 +54,11 @@ const (
// Advertisements, as a host.
defaultDiscoverDefaultRouters = true
+ // defaultDiscoverMoreSpecificRoutes is the default configuration for
+ // whether or not to discover more-specific routes from incoming Router
+ // Advertisements, as a host.
+ defaultDiscoverMoreSpecificRoutes = true
+
// defaultDiscoverOnLinkPrefixes is the default configuration for
// whether or not to discover on-link prefixes from incoming Router
// Advertisements' Prefix Information option, as a host.
@@ -352,12 +357,18 @@ type NDPConfigurations struct {
// DiscoverDefaultRouters determines whether or not default routers are
// discovered from Router Advertisements, as per RFC 4861 section 6. This
- // configuration is ignored if HandleRAs is false.
+ // configuration is ignored if RAs will not be processed (see HandleRAs).
DiscoverDefaultRouters bool
+ // DiscoverMoreSpecificRoutes determines whether or not more specific routes
+ // are discovered from Router Advertisements, as per RFC 4191. This
+ // configuration is ignored if RAs will not be processed (see HandleRAs).
+ DiscoverMoreSpecificRoutes bool
+
// DiscoverOnLinkPrefixes determines whether or not on-link prefixes are
// discovered from Router Advertisements' Prefix Information option, as per
- // RFC 4861 section 6. This configuration is ignored if HandleRAs is false.
+ // RFC 4861 section 6. This configuration is ignored if RAs will not be
+ // processed (see HandleRAs).
DiscoverOnLinkPrefixes bool
// AutoGenGlobalAddresses determines whether or not an IPv6 endpoint performs
@@ -408,6 +419,7 @@ func DefaultNDPConfigurations() NDPConfigurations {
MaxRtrSolicitationDelay: defaultMaxRtrSolicitationDelay,
HandleRAs: defaultHandleRAs,
DiscoverDefaultRouters: defaultDiscoverDefaultRouters,
+ DiscoverMoreSpecificRoutes: defaultDiscoverMoreSpecificRoutes,
DiscoverOnLinkPrefixes: defaultDiscoverOnLinkPrefixes,
AutoGenGlobalAddresses: defaultAutoGenGlobalAddresses,
AutoGenTempGlobalAddresses: defaultAutoGenTempGlobalAddresses,
@@ -786,6 +798,32 @@ func (ndp *ndpState) handleRA(ip tcpip.Address, ra header.NDPRouterAdvert) {
if opt.AutonomousAddressConfigurationFlag() {
ndp.handleAutonomousPrefixInformation(opt)
}
+
+ case header.NDPRouteInformation:
+ if !ndp.configs.DiscoverMoreSpecificRoutes {
+ continue
+ }
+
+ dest, err := opt.Prefix()
+ if err != nil {
+ panic(fmt.Sprintf("%T.Prefix(): %s", opt, err))
+ }
+
+ prf := opt.RoutePreference()
+ if prf == header.ReservedRoutePreference {
+ // As per RFC 4191 section 2.3,
+ //
+ // Prf (Route Preference)
+ // 2-bit signed integer. The Route Preference indicates
+ // whether to prefer the router associated with this prefix
+ // over others, when multiple identical prefixes (for
+ // different routers) have been received. If the Reserved
+ // (10) value is received, the Route Information Option MUST
+ // be ignored.
+ continue
+ }
+
+ ndp.handleOffLinkRouteDiscovery(offLinkRoute{dest: dest, router: ip}, opt.RouteLifetime(), prf)
}
// TODO(b/141556115): Do (MTU) Parameter Discovery.
diff --git a/pkg/tcpip/stack/ndp_test.go b/pkg/tcpip/stack/ndp_test.go
index 9623d9c28..ca2250ad6 100644
--- a/pkg/tcpip/stack/ndp_test.go
+++ b/pkg/tcpip/stack/ndp_test.go
@@ -1152,6 +1152,39 @@ func raBufWithPI(ip tcpip.Address, rl uint16, prefix tcpip.AddressWithPrefix, on
})
}
+// raBufWithRIO returns a valid NDP Router Advertisement with a single Route
+// Information option.
+//
+// All fields in the RA will be zero except the RIO option.
+func raBufWithRIO(t *testing.T, ip tcpip.Address, prefix tcpip.AddressWithPrefix, lifetimeSeconds uint32, prf header.NDPRoutePreference) *stack.PacketBuffer {
+ // buf will hold the route information option after the Type and Length
+ // fields.
+ //
+ // 2.3. Route Information Option
+ //
+ // 0 1 2 3
+ // 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+ // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ // | Type | Length | Prefix Length |Resvd|Prf|Resvd|
+ // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ // | Route Lifetime |
+ // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ // | Prefix (Variable Length) |
+ // . .
+ // . .
+ // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+ var buf [22]byte
+ buf[0] = uint8(prefix.PrefixLen)
+ buf[1] = byte(prf) << 3
+ binary.BigEndian.PutUint32(buf[2:], lifetimeSeconds)
+ if n := copy(buf[6:], prefix.Address); n != len(prefix.Address) {
+ t.Fatalf("got copy(...) = %d, want = %d", n, len(prefix.Address))
+ }
+ return raBufWithOpts(ip, 0 /* router lifetime */, header.NDPOptionsSerializer{
+ header.NDPRouteInformation(buf[:]),
+ })
+}
+
func TestDynamicConfigurationsDisabled(t *testing.T) {
const (
nicID = 1
@@ -1308,8 +1341,8 @@ func boolToUint64(v bool) uint64 {
return 0
}
-func checkOffLinkRouteEvent(e ndpOffLinkRouteEvent, nicID tcpip.NICID, router tcpip.Address, prf header.NDPRoutePreference, updated bool) string {
- return cmp.Diff(ndpOffLinkRouteEvent{nicID: nicID, subnet: header.IPv6EmptySubnet, router: router, prf: prf, updated: updated}, e, cmp.AllowUnexported(e))
+func checkOffLinkRouteEvent(e ndpOffLinkRouteEvent, nicID tcpip.NICID, subnet tcpip.Subnet, router tcpip.Address, prf header.NDPRoutePreference, updated bool) string {
+ return cmp.Diff(ndpOffLinkRouteEvent{nicID: nicID, subnet: subnet, router: router, prf: prf, updated: updated}, e, cmp.AllowUnexported(e))
}
func testWithRAs(t *testing.T, f func(*testing.T, ipv6.HandleRAsConfiguration, bool)) {
@@ -1342,122 +1375,167 @@ func testWithRAs(t *testing.T, f func(*testing.T, ipv6.HandleRAsConfiguration, b
}
}
-func TestRouterDiscovery(t *testing.T) {
+func TestOffLinkRouteDiscovery(t *testing.T) {
const nicID = 1
- testWithRAs(t, func(t *testing.T, handleRAs ipv6.HandleRAsConfiguration, forwarding bool) {
- ndpDisp := ndpDispatcher{
- offLinkRouteC: make(chan ndpOffLinkRouteEvent, 1),
- }
- e := channel.New(0, 1280, linkAddr1)
- clock := faketime.NewManualClock()
- s := stack.New(stack.Options{
- NetworkProtocols: []stack.NetworkProtocolFactory{ipv6.NewProtocolWithOptions(ipv6.Options{
- NDPConfigs: ipv6.NDPConfigurations{
- HandleRAs: handleRAs,
- DiscoverDefaultRouters: true,
- },
- NDPDisp: &ndpDisp,
- })},
- Clock: clock,
- })
+ moreSpecificPrefix := tcpip.AddressWithPrefix{Address: testutil.MustParse6("a00::"), PrefixLen: 16}
+ tests := []struct {
+ name string
- expectOffLinkRouteEvent := func(addr tcpip.Address, prf header.NDPRoutePreference, updated bool) {
- t.Helper()
+ discoverDefaultRouters bool
+ discoverMoreSpecificRoutes bool
- select {
- case e := <-ndpDisp.offLinkRouteC:
- if diff := checkOffLinkRouteEvent(e, nicID, addr, prf, updated); diff != "" {
- t.Errorf("off-link route event mismatch (-want +got):\n%s", diff)
+ dest tcpip.Subnet
+ ra func(*testing.T, tcpip.Address, uint16, header.NDPRoutePreference) *stack.PacketBuffer
+ }{
+ {
+ name: "Default router discovery",
+ discoverDefaultRouters: true,
+ discoverMoreSpecificRoutes: false,
+ dest: header.IPv6EmptySubnet,
+ ra: func(_ *testing.T, router tcpip.Address, lifetimeSeconds uint16, prf header.NDPRoutePreference) *stack.PacketBuffer {
+ return raBufWithPrf(router, lifetimeSeconds, prf)
+ },
+ },
+ {
+ name: "More-specific route discovery",
+ discoverDefaultRouters: false,
+ discoverMoreSpecificRoutes: true,
+ dest: moreSpecificPrefix.Subnet(),
+ ra: func(t *testing.T, router tcpip.Address, lifetimeSeconds uint16, prf header.NDPRoutePreference) *stack.PacketBuffer {
+ return raBufWithRIO(t, router, moreSpecificPrefix, uint32(lifetimeSeconds), prf)
+ },
+ },
+ }
+
+ for _, test := range tests {
+ t.Run(test.name, func(t *testing.T) {
+ testWithRAs(t, func(t *testing.T, handleRAs ipv6.HandleRAsConfiguration, forwarding bool) {
+ ndpDisp := ndpDispatcher{
+ offLinkRouteC: make(chan ndpOffLinkRouteEvent, 1),
}
- default:
- t.Fatal("expected router discovery event")
- }
- }
+ e := channel.New(0, 1280, linkAddr1)
+ clock := faketime.NewManualClock()
+ s := stack.New(stack.Options{
+ NetworkProtocols: []stack.NetworkProtocolFactory{ipv6.NewProtocolWithOptions(ipv6.Options{
+ NDPConfigs: ipv6.NDPConfigurations{
+ HandleRAs: handleRAs,
+ DiscoverDefaultRouters: test.discoverDefaultRouters,
+ DiscoverMoreSpecificRoutes: test.discoverMoreSpecificRoutes,
+ },
+ NDPDisp: &ndpDisp,
+ })},
+ Clock: clock,
+ })
- expectAsyncOffLinkRouteInvalidationEvent := func(addr tcpip.Address, timeout time.Duration) {
- t.Helper()
+ expectOffLinkRouteEvent := func(addr tcpip.Address, prf header.NDPRoutePreference, updated bool) {
+ t.Helper()
- clock.Advance(timeout)
- select {
- case e := <-ndpDisp.offLinkRouteC:
- var prf header.NDPRoutePreference
- if diff := checkOffLinkRouteEvent(e, nicID, addr, prf, false); diff != "" {
- t.Errorf("off-link route event mismatch (-want +got):\n%s", diff)
+ select {
+ case e := <-ndpDisp.offLinkRouteC:
+ if diff := checkOffLinkRouteEvent(e, nicID, test.dest, addr, prf, updated); diff != "" {
+ t.Errorf("off-link route event mismatch (-want +got):\n%s", diff)
+ }
+ default:
+ t.Fatal("expected router discovery event")
+ }
}
- default:
- t.Fatal("timed out waiting for router discovery event")
- }
- }
- if err := s.SetForwardingDefaultAndAllNICs(ipv6.ProtocolNumber, forwarding); err != nil {
- t.Fatalf("SetForwardingDefaultAndAllNICs(%d, %t): %s", ipv6.ProtocolNumber, forwarding, err)
- }
+ expectAsyncOffLinkRouteInvalidationEvent := func(addr tcpip.Address, timeout time.Duration) {
+ t.Helper()
- if err := s.CreateNIC(nicID, e); err != nil {
- t.Fatalf("CreateNIC(%d, _): %s", nicID, err)
- }
+ clock.Advance(timeout)
+ select {
+ case e := <-ndpDisp.offLinkRouteC:
+ var prf header.NDPRoutePreference
+ if diff := checkOffLinkRouteEvent(e, nicID, test.dest, addr, prf, false); diff != "" {
+ t.Errorf("off-link route event mismatch (-want +got):\n%s", diff)
+ }
+ default:
+ t.Fatal("timed out waiting for router discovery event")
+ }
+ }
- // Rx an RA from lladdr2 with zero lifetime. It should not be
- // remembered.
- e.InjectInbound(header.IPv6ProtocolNumber, raBufSimple(llAddr2, 0))
- select {
- case <-ndpDisp.offLinkRouteC:
- t.Fatal("unexpectedly updated an off-link route with 0 lifetime")
- default:
- }
+ if err := s.SetForwardingDefaultAndAllNICs(ipv6.ProtocolNumber, forwarding); err != nil {
+ t.Fatalf("SetForwardingDefaultAndAllNICs(%d, %t): %s", ipv6.ProtocolNumber, forwarding, err)
+ }
- // Rx an RA from lladdr2 with a huge lifetime and reserved preference value
- // (which should be interpreted as the default (medium) preference value).
- e.InjectInbound(header.IPv6ProtocolNumber, raBufWithPrf(llAddr2, 1000, header.ReservedRoutePreference))
- expectOffLinkRouteEvent(llAddr2, header.MediumRoutePreference, true)
-
- // Rx an RA from another router (lladdr3) with non-zero lifetime and
- // non-default preference value.
- const l3LifetimeSeconds = 6
- e.InjectInbound(header.IPv6ProtocolNumber, raBufWithPrf(llAddr3, l3LifetimeSeconds, header.HighRoutePreference))
- expectOffLinkRouteEvent(llAddr3, header.HighRoutePreference, true)
-
- // Rx an RA from lladdr2 with lesser lifetime and default (medium)
- // preference value.
- const l2LifetimeSeconds = 2
- e.InjectInbound(header.IPv6ProtocolNumber, raBufSimple(llAddr2, l2LifetimeSeconds))
- select {
- case <-ndpDisp.offLinkRouteC:
- t.Fatal("should not receive a off-link route event when updating lifetimes for known routers")
- default:
- }
+ if err := s.CreateNIC(nicID, e); err != nil {
+ t.Fatalf("CreateNIC(%d, _): %s", nicID, err)
+ }
- // Rx an RA from lladdr2 with a different preference.
- e.InjectInbound(header.IPv6ProtocolNumber, raBufWithPrf(llAddr2, l2LifetimeSeconds, header.LowRoutePreference))
- expectOffLinkRouteEvent(llAddr2, header.LowRoutePreference, true)
-
- // Wait for lladdr2's router invalidation job to execute. The lifetime
- // of the router should have been updated to the most recent (smaller)
- // lifetime.
- //
- // Wait for the normal lifetime plus an extra bit for the
- // router to get invalidated. If we don't get an invalidation
- // event after this time, then something is wrong.
- expectAsyncOffLinkRouteInvalidationEvent(llAddr2, l2LifetimeSeconds*time.Second)
-
- // Rx an RA from lladdr2 with huge lifetime.
- e.InjectInbound(header.IPv6ProtocolNumber, raBufSimple(llAddr2, 1000))
- expectOffLinkRouteEvent(llAddr2, header.MediumRoutePreference, true)
-
- // Rx an RA from lladdr2 with zero lifetime. It should be invalidated.
- e.InjectInbound(header.IPv6ProtocolNumber, raBufSimple(llAddr2, 0))
- expectOffLinkRouteEvent(llAddr2, header.MediumRoutePreference, false)
-
- // Wait for lladdr3's router invalidation job to execute. The lifetime
- // of the router should have been updated to the most recent (smaller)
- // lifetime.
- //
- // Wait for the normal lifetime plus an extra bit for the
- // router to get invalidated. If we don't get an invalidation
- // event after this time, then something is wrong.
- expectAsyncOffLinkRouteInvalidationEvent(llAddr3, l3LifetimeSeconds*time.Second)
- })
+ // Rx an RA from lladdr2 with zero lifetime. It should not be
+ // remembered.
+ e.InjectInbound(header.IPv6ProtocolNumber, test.ra(t, llAddr2, 0, header.MediumRoutePreference))
+ select {
+ case <-ndpDisp.offLinkRouteC:
+ t.Fatal("unexpectedly updated an off-link route with 0 lifetime")
+ default:
+ }
+
+ // Discover an off-link route through llAddr2.
+ e.InjectInbound(header.IPv6ProtocolNumber, test.ra(t, llAddr2, 1000, header.ReservedRoutePreference))
+ if test.discoverMoreSpecificRoutes {
+ // The reserved value is considered invalid with more-specific route
+ // discovery so we inject the same packet but with the default
+ // (medium) preference value.
+ select {
+ case <-ndpDisp.offLinkRouteC:
+ t.Fatal("unexpectedly updated an off-link route with a reserved preference value")
+ default:
+ }
+ e.InjectInbound(header.IPv6ProtocolNumber, test.ra(t, llAddr2, 1000, header.MediumRoutePreference))
+ }
+ expectOffLinkRouteEvent(llAddr2, header.MediumRoutePreference, true)
+
+ // Rx an RA from another router (lladdr3) with non-zero lifetime and
+ // non-default preference value.
+ const l3LifetimeSeconds = 6
+ e.InjectInbound(header.IPv6ProtocolNumber, test.ra(t, llAddr3, l3LifetimeSeconds, header.HighRoutePreference))
+ expectOffLinkRouteEvent(llAddr3, header.HighRoutePreference, true)
+
+ // Rx an RA from lladdr2 with lesser lifetime and default (medium)
+ // preference value.
+ const l2LifetimeSeconds = 2
+ e.InjectInbound(header.IPv6ProtocolNumber, test.ra(t, llAddr2, l2LifetimeSeconds, header.MediumRoutePreference))
+ select {
+ case <-ndpDisp.offLinkRouteC:
+ t.Fatal("should not receive a off-link route event when updating lifetimes for known routers")
+ default:
+ }
+
+ // Rx an RA from lladdr2 with a different preference.
+ e.InjectInbound(header.IPv6ProtocolNumber, test.ra(t, llAddr2, l2LifetimeSeconds, header.LowRoutePreference))
+ expectOffLinkRouteEvent(llAddr2, header.LowRoutePreference, true)
+
+ // Wait for lladdr2's router invalidation job to execute. The lifetime
+ // of the router should have been updated to the most recent (smaller)
+ // lifetime.
+ //
+ // Wait for the normal lifetime plus an extra bit for the
+ // router to get invalidated. If we don't get an invalidation
+ // event after this time, then something is wrong.
+ expectAsyncOffLinkRouteInvalidationEvent(llAddr2, l2LifetimeSeconds*time.Second)
+
+ // Rx an RA from lladdr2 with huge lifetime.
+ e.InjectInbound(header.IPv6ProtocolNumber, test.ra(t, llAddr2, 1000, header.MediumRoutePreference))
+ expectOffLinkRouteEvent(llAddr2, header.MediumRoutePreference, true)
+
+ // Rx an RA from lladdr2 with zero lifetime. It should be invalidated.
+ e.InjectInbound(header.IPv6ProtocolNumber, test.ra(t, llAddr2, 0, header.MediumRoutePreference))
+ expectOffLinkRouteEvent(llAddr2, header.MediumRoutePreference, false)
+
+ // Wait for lladdr3's router invalidation job to execute. The lifetime
+ // of the router should have been updated to the most recent (smaller)
+ // lifetime.
+ //
+ // Wait for the normal lifetime plus an extra bit for the
+ // router to get invalidated. If we don't get an invalidation
+ // event after this time, then something is wrong.
+ expectAsyncOffLinkRouteInvalidationEvent(llAddr3, l3LifetimeSeconds*time.Second)
+ })
+ })
+ }
}
// TestRouterDiscoveryMaxRouters tests that only
@@ -1494,7 +1572,7 @@ func TestRouterDiscoveryMaxRouters(t *testing.T) {
if i <= ipv6.MaxDiscoveredOffLinkRoutes {
select {
case e := <-ndpDisp.offLinkRouteC:
- if diff := checkOffLinkRouteEvent(e, nicID, llAddr, header.MediumRoutePreference, true); diff != "" {
+ if diff := checkOffLinkRouteEvent(e, nicID, header.IPv6EmptySubnet, llAddr, header.MediumRoutePreference, true); diff != "" {
t.Errorf("off-link route event mismatch (-want +got):\n%s", diff)
}
default:
@@ -4583,7 +4661,7 @@ func TestNoCleanupNDPStateWhenForwardingEnabled(t *testing.T) {
)
select {
case e := <-ndpDisp.offLinkRouteC:
- if diff := checkOffLinkRouteEvent(e, nicID, llAddr3, header.MediumRoutePreference, true /* discovered */); diff != "" {
+ if diff := checkOffLinkRouteEvent(e, nicID, header.IPv6EmptySubnet, llAddr3, header.MediumRoutePreference, true /* discovered */); diff != "" {
t.Errorf("off-link route event mismatch (-want +got):\n%s", diff)
}
default:
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-02 18:34:10 +0000