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-rw-r--r--pkg/tcpip/network/ipv6/ipv6.go43
-rw-r--r--pkg/tcpip/network/ipv6/ndp.go62
-rw-r--r--pkg/tcpip/stack/ndp_test.go249
3 files changed, 222 insertions, 132 deletions
diff --git a/pkg/tcpip/network/ipv6/ipv6.go b/pkg/tcpip/network/ipv6/ipv6.go
index c7a92be6c..659057fa7 100644
--- a/pkg/tcpip/network/ipv6/ipv6.go
+++ b/pkg/tcpip/network/ipv6/ipv6.go
@@ -420,8 +420,6 @@ func (e *endpoint) transitionForwarding(forwarding bool) {
defer e.mu.Unlock()
if forwarding {
- e.mu.ndp.stopSolicitingRouters()
-
// As per RFC 4291 section 2.8:
//
// A router is required to recognize all addresses that a host is
@@ -445,28 +443,19 @@ func (e *endpoint) transitionForwarding(forwarding bool) {
panic(fmt.Sprintf("e.joinGroupLocked(%s): %s", g, err))
}
}
-
- return
- }
-
- for _, g := range allRoutersGroups {
- switch err := e.leaveGroupLocked(g).(type) {
- case nil:
- case *tcpip.ErrBadLocalAddress:
- // The endpoint may have already left the multicast group.
- default:
- panic(fmt.Sprintf("e.leaveGroupLocked(%s): %s", g, err))
+ } else {
+ for _, g := range allRoutersGroups {
+ switch err := e.leaveGroupLocked(g).(type) {
+ case nil:
+ case *tcpip.ErrBadLocalAddress:
+ // The endpoint may have already left the multicast group.
+ default:
+ panic(fmt.Sprintf("e.leaveGroupLocked(%s): %s", g, err))
+ }
}
}
- // When transitioning into an IPv6 host, NDP router solicitations are
- // started if the endpoint is enabled.
- //
- // If the endpoint is not currently enabled, routers will be solicited when
- // the endpoint becomes enabled (if it is still a host).
- if e.Enabled() {
- e.mu.ndp.startSolicitingRouters()
- }
+ e.mu.ndp.forwardingChanged(forwarding)
}
// Enable implements stack.NetworkEndpoint.
@@ -548,17 +537,7 @@ func (e *endpoint) Enable() tcpip.Error {
e.mu.ndp.doSLAAC(header.IPv6LinkLocalPrefix.Subnet(), header.NDPInfiniteLifetime, header.NDPInfiniteLifetime)
}
- // If we are operating as a router, then do not solicit routers since we
- // won't process the RAs anyway.
- //
- // Routers do not process Router Advertisements (RA) the same way a host
- // does. That is, routers do not learn from RAs (e.g. on-link prefixes
- // and default routers). Therefore, soliciting RAs from other routers on
- // a link is unnecessary for routers.
- if !e.protocol.Forwarding() {
- e.mu.ndp.startSolicitingRouters()
- }
-
+ e.mu.ndp.startSolicitingRouters()
return nil
}
diff --git a/pkg/tcpip/network/ipv6/ndp.go b/pkg/tcpip/network/ipv6/ndp.go
index be6a2e161..b29fed347 100644
--- a/pkg/tcpip/network/ipv6/ndp.go
+++ b/pkg/tcpip/network/ipv6/ndp.go
@@ -334,10 +334,27 @@ func (c HandleRAsConfiguration) String() string {
}
}
+// enabled returns true iff Router Advertisements may be handled given the
+// specified forwarding status.
+func (c HandleRAsConfiguration) enabled(forwarding bool) bool {
+ switch c {
+ case HandlingRAsDisabled:
+ return false
+ case HandlingRAsEnabledWhenForwardingDisabled:
+ return !forwarding
+ case HandlingRAsAlwaysEnabled:
+ return true
+ default:
+ panic(fmt.Sprintf("unhandled HandleRAsConfiguration = %d", c))
+ }
+}
+
// NDPConfigurations is the NDP configurations for the netstack.
type NDPConfigurations struct {
// The number of Router Solicitation messages to send when the IPv6 endpoint
// becomes enabled.
+ //
+ // Ignored unless configured to handle Router Advertisements.
MaxRtrSolicitations uint8
// The amount of time between transmitting Router Solicitation messages.
@@ -688,18 +705,9 @@ func (ndp *ndpState) handleRA(ip tcpip.Address, ra header.NDPRouterAdvert) {
// per-interface basis; it is a protocol-wide configuration, so we check the
// protocol's forwarding flag to determine if the IPv6 endpoint is forwarding
// packets.
- switch ndp.configs.HandleRAs {
- case HandlingRAsDisabled:
+ if !ndp.configs.HandleRAs.enabled(ndp.ep.protocol.Forwarding()) {
ndp.ep.stats.localStats.UnhandledRouterAdvertisements.Increment()
return
- case HandlingRAsEnabledWhenForwardingDisabled:
- if ndp.ep.protocol.Forwarding() {
- ndp.ep.stats.localStats.UnhandledRouterAdvertisements.Increment()
- return
- }
- case HandlingRAsAlwaysEnabled:
- default:
- panic(fmt.Sprintf("unhandled HandleRAs configuration = %d", ndp.configs.HandleRAs))
}
// Only worry about the DHCPv6 configuration if we have an NDPDispatcher as we
@@ -1686,6 +1694,10 @@ func (ndp *ndpState) cleanupState() {
// startSolicitingRouters starts soliciting routers, as per RFC 4861 section
// 6.3.7. If routers are already being solicited, this function does nothing.
//
+// If ndp is not configured to handle Router Advertisements, routers will not
+// be solicited as there is no point soliciting routers if we don't handle their
+// advertisements.
+//
// The IPv6 endpoint that ndp belongs to MUST be locked.
func (ndp *ndpState) startSolicitingRouters() {
if ndp.rtrSolicitTimer.timer != nil {
@@ -1698,6 +1710,10 @@ func (ndp *ndpState) startSolicitingRouters() {
return
}
+ if !ndp.configs.HandleRAs.enabled(ndp.ep.protocol.Forwarding()) {
+ return
+ }
+
// Calculate the random delay before sending our first RS, as per RFC
// 4861 section 6.3.7.
var delay time.Duration
@@ -1790,6 +1806,32 @@ func (ndp *ndpState) startSolicitingRouters() {
}
}
+// forwardingChanged handles a change in forwarding configuration.
+//
+// If transitioning to a host, router solicitation will be started. Otherwise,
+// router solicitation will be stopped if NDP is not configured to handle RAs
+// as a router.
+//
+// Precondition: ndp.ep.mu must be locked.
+func (ndp *ndpState) forwardingChanged(forwarding bool) {
+ if forwarding {
+ if ndp.configs.HandleRAs.enabled(forwarding) {
+ return
+ }
+
+ ndp.stopSolicitingRouters()
+ return
+ }
+
+ // Solicit routers when transitioning to a host.
+ //
+ // If the endpoint is not currently enabled, routers will be solicited when
+ // the endpoint becomes enabled (if it is still a host).
+ if ndp.ep.Enabled() {
+ ndp.startSolicitingRouters()
+ }
+}
+
// stopSolicitingRouters stops soliciting routers. If routers are not currently
// being solicited, this function does nothing.
//
diff --git a/pkg/tcpip/stack/ndp_test.go b/pkg/tcpip/stack/ndp_test.go
index 011571106..c585b81b2 100644
--- a/pkg/tcpip/stack/ndp_test.go
+++ b/pkg/tcpip/stack/ndp_test.go
@@ -1147,7 +1147,10 @@ func raBufWithPI(ip tcpip.Address, rl uint16, prefix tcpip.AddressWithPrefix, on
}
func TestDynamicConfigurationsDisabled(t *testing.T) {
- const nicID = 1
+ const (
+ nicID = 1
+ maxRtrSolicitDelay = time.Second
+ )
prefix := tcpip.AddressWithPrefix{
Address: testutil.MustParse6("102:304:506:708::"),
@@ -1206,7 +1209,12 @@ func TestDynamicConfigurationsDisabled(t *testing.T) {
}
ndpConfigs := test.config(enable)
ndpConfigs.HandleRAs = handle
+ ndpConfigs.MaxRtrSolicitations = 1
+ ndpConfigs.RtrSolicitationInterval = maxRtrSolicitDelay
+ ndpConfigs.MaxRtrSolicitationDelay = maxRtrSolicitDelay
+ clock := faketime.NewManualClock()
s := stack.New(stack.Options{
+ Clock: clock,
NetworkProtocols: []stack.NetworkProtocolFactory{ipv6.NewProtocolWithOptions(ipv6.Options{
NDPConfigs: ndpConfigs,
NDPDisp: &ndpDisp,
@@ -1216,15 +1224,12 @@ func TestDynamicConfigurationsDisabled(t *testing.T) {
t.Fatalf("SetForwarding(%d, %t): %s", ipv6.ProtocolNumber, forwarding, err)
}
- e := channel.New(0, 1280, linkAddr1)
+ e := channel.New(1, 1280, linkAddr1)
if err := s.CreateNIC(nicID, e); err != nil {
t.Fatalf("CreateNIC(%d, _): %s", nicID, err)
}
- e.InjectInbound(header.IPv6ProtocolNumber, test.ra.Clone())
-
- // Make sure that the unhandled RA stat is only incremented when RAs
- // are configured to be unhandled.
+ handleRAsDisabled := handle == ipv6.HandlingRAsDisabled || forwarding
ep, err := s.GetNetworkEndpoint(nicID, ipv6.ProtocolNumber)
if err != nil {
t.Fatalf("s.GetNetworkEndpoint(%d, %d): %s", nicID, ipv6.ProtocolNumber, err)
@@ -1234,16 +1239,41 @@ func TestDynamicConfigurationsDisabled(t *testing.T) {
if !ok {
t.Fatalf("got v6Stats = %T, expected = %T", stats, v6Stats)
}
- want := uint64(0)
- if handle == ipv6.HandlingRAsDisabled || forwarding {
- want = 1
+
+ // Make sure that when handling RAs are enabled, we solicit routers.
+ clock.Advance(maxRtrSolicitDelay)
+ if got, want := v6Stats.ICMP.PacketsSent.RouterSolicit.Value(), boolToUint64(!handleRAsDisabled); got != want {
+ t.Errorf("got v6Stats.ICMP.PacketsSent.RouterSolicit.Value() = %d, want = %d", got, want)
}
- if got := v6Stats.UnhandledRouterAdvertisements.Value(); got != want {
- t.Fatalf("got v6Stats.UnhandledRouterAdvertisements.Value() = %d, want = %d", got, want)
+ if handleRAsDisabled {
+ if p, ok := e.Read(); ok {
+ t.Errorf("unexpectedly got a packet = %#v", p)
+ }
+ } else if p, ok := e.Read(); !ok {
+ t.Error("expected router solicitation packet")
+ } else if p.Proto != header.IPv6ProtocolNumber {
+ t.Errorf("got Proto = %d, want = %d", p.Proto, header.IPv6ProtocolNumber)
+ } else {
+ if want := header.EthernetAddressFromMulticastIPv6Address(header.IPv6AllRoutersLinkLocalMulticastAddress); p.Route.RemoteLinkAddress != want {
+ t.Errorf("got remote link address = %s, want = %s", p.Route.RemoteLinkAddress, want)
+ }
+
+ checker.IPv6(t, stack.PayloadSince(p.Pkt.NetworkHeader()),
+ checker.SrcAddr(header.IPv6Any),
+ checker.DstAddr(header.IPv6AllRoutersLinkLocalMulticastAddress),
+ checker.TTL(header.NDPHopLimit),
+ checker.NDPRS(checker.NDPRSOptions(nil)),
+ )
}
- // Make sure we did not discover any routers or prefixes, or perform
- // SLAAC.
+ // Make sure we do not discover any routers or prefixes, or perform
+ // SLAAC on reception of an RA.
+ e.InjectInbound(header.IPv6ProtocolNumber, test.ra.Clone())
+ // Make sure that the unhandled RA stat is only incremented when
+ // handling RAs is disabled.
+ if got, want := v6Stats.UnhandledRouterAdvertisements.Value(), boolToUint64(handleRAsDisabled); got != want {
+ t.Errorf("got v6Stats.UnhandledRouterAdvertisements.Value() = %d, want = %d", got, want)
+ }
select {
case e := <-ndpDisp.routerC:
t.Errorf("unexpectedly discovered a router when configured not to: %#v", e)
@@ -1265,6 +1295,13 @@ func TestDynamicConfigurationsDisabled(t *testing.T) {
}
}
+func boolToUint64(v bool) uint64 {
+ if v {
+ return 1
+ }
+ return 0
+}
+
// Check e to make sure that the event is for addr on nic with ID 1, and the
// discovered flag set to discovered.
func checkRouterEvent(e ndpRouterEvent, addr tcpip.Address, discovered bool) string {
@@ -5299,96 +5336,127 @@ func TestRouterSolicitation(t *testing.T) {
},
}
+ subTests := []struct {
+ name string
+ handleRAs ipv6.HandleRAsConfiguration
+ afterFirstRS func(*testing.T, *stack.Stack)
+ }{
+ {
+ name: "Handle RAs when forwarding disabled",
+ handleRAs: ipv6.HandlingRAsEnabledWhenForwardingDisabled,
+ afterFirstRS: func(*testing.T, *stack.Stack) {},
+ },
+
+ // Enabling forwarding when RAs are always configured to be handled
+ // should not stop router solicitations.
+ {
+ name: "Handle RAs always",
+ handleRAs: ipv6.HandlingRAsAlwaysEnabled,
+ afterFirstRS: func(t *testing.T, s *stack.Stack) {
+ if err := s.SetForwarding(ipv6.ProtocolNumber, true); err != nil {
+ t.Fatalf("SetForwarding(%d, true): %s", ipv6.ProtocolNumber, err)
+ }
+ },
+ },
+ }
+
for _, test := range tests {
t.Run(test.name, func(t *testing.T) {
- clock := faketime.NewManualClock()
- e := channelLinkWithHeaderLength{
- Endpoint: channel.New(int(test.maxRtrSolicit), 1280, test.linkAddr),
- headerLength: test.linkHeaderLen,
- }
- e.Endpoint.LinkEPCapabilities |= stack.CapabilityResolutionRequired
- waitForPkt := func(timeout time.Duration) {
- t.Helper()
+ for _, subTest := range subTests {
+ t.Run(subTest.name, func(t *testing.T) {
+ clock := faketime.NewManualClock()
+ e := channelLinkWithHeaderLength{
+ Endpoint: channel.New(int(test.maxRtrSolicit), 1280, test.linkAddr),
+ headerLength: test.linkHeaderLen,
+ }
+ e.Endpoint.LinkEPCapabilities |= stack.CapabilityResolutionRequired
+ waitForPkt := func(timeout time.Duration) {
+ t.Helper()
+
+ clock.Advance(timeout)
+ p, ok := e.Read()
+ if !ok {
+ t.Fatal("expected router solicitation packet")
+ }
- clock.Advance(timeout)
- p, ok := e.Read()
- if !ok {
- t.Fatal("expected router solicitation packet")
- }
+ if p.Proto != header.IPv6ProtocolNumber {
+ t.Fatalf("got Proto = %d, want = %d", p.Proto, header.IPv6ProtocolNumber)
+ }
- if p.Proto != header.IPv6ProtocolNumber {
- t.Fatalf("got Proto = %d, want = %d", p.Proto, header.IPv6ProtocolNumber)
- }
+ // Make sure the right remote link address is used.
+ if want := header.EthernetAddressFromMulticastIPv6Address(header.IPv6AllRoutersLinkLocalMulticastAddress); p.Route.RemoteLinkAddress != want {
+ t.Errorf("got remote link address = %s, want = %s", p.Route.RemoteLinkAddress, want)
+ }
- // Make sure the right remote link address is used.
- if want := header.EthernetAddressFromMulticastIPv6Address(header.IPv6AllRoutersLinkLocalMulticastAddress); p.Route.RemoteLinkAddress != want {
- t.Errorf("got remote link address = %s, want = %s", p.Route.RemoteLinkAddress, want)
- }
+ checker.IPv6(t, stack.PayloadSince(p.Pkt.NetworkHeader()),
+ checker.SrcAddr(test.expectedSrcAddr),
+ checker.DstAddr(header.IPv6AllRoutersLinkLocalMulticastAddress),
+ checker.TTL(header.NDPHopLimit),
+ checker.NDPRS(checker.NDPRSOptions(test.expectedNDPOpts)),
+ )
- checker.IPv6(t, stack.PayloadSince(p.Pkt.NetworkHeader()),
- checker.SrcAddr(test.expectedSrcAddr),
- checker.DstAddr(header.IPv6AllRoutersLinkLocalMulticastAddress),
- checker.TTL(header.NDPHopLimit),
- checker.NDPRS(checker.NDPRSOptions(test.expectedNDPOpts)),
- )
+ if l, want := p.Pkt.AvailableHeaderBytes(), int(test.linkHeaderLen); l != want {
+ t.Errorf("got p.Pkt.AvailableHeaderBytes() = %d; want = %d", l, want)
+ }
+ }
+ waitForNothing := func(timeout time.Duration) {
+ t.Helper()
- if l, want := p.Pkt.AvailableHeaderBytes(), int(test.linkHeaderLen); l != want {
- t.Errorf("got p.Pkt.AvailableHeaderBytes() = %d; want = %d", l, want)
- }
- }
- waitForNothing := func(timeout time.Duration) {
- t.Helper()
+ clock.Advance(timeout)
+ if p, ok := e.Read(); ok {
+ t.Fatalf("unexpectedly got a packet = %#v", p)
+ }
+ }
+ s := stack.New(stack.Options{
+ NetworkProtocols: []stack.NetworkProtocolFactory{ipv6.NewProtocolWithOptions(ipv6.Options{
+ NDPConfigs: ipv6.NDPConfigurations{
+ HandleRAs: subTest.handleRAs,
+ MaxRtrSolicitations: test.maxRtrSolicit,
+ RtrSolicitationInterval: test.rtrSolicitInt,
+ MaxRtrSolicitationDelay: test.maxRtrSolicitDelay,
+ },
+ })},
+ Clock: clock,
+ })
+ if err := s.CreateNIC(nicID, &e); err != nil {
+ t.Fatalf("CreateNIC(%d, _) = %s", nicID, err)
+ }
- clock.Advance(timeout)
- if p, ok := e.Read(); ok {
- t.Fatalf("unexpectedly got a packet = %#v", p)
- }
- }
- s := stack.New(stack.Options{
- NetworkProtocols: []stack.NetworkProtocolFactory{ipv6.NewProtocolWithOptions(ipv6.Options{
- NDPConfigs: ipv6.NDPConfigurations{
- MaxRtrSolicitations: test.maxRtrSolicit,
- RtrSolicitationInterval: test.rtrSolicitInt,
- MaxRtrSolicitationDelay: test.maxRtrSolicitDelay,
- },
- })},
- Clock: clock,
- })
- if err := s.CreateNIC(nicID, &e); err != nil {
- t.Fatalf("CreateNIC(%d, _) = %s", nicID, err)
- }
+ if addr := test.nicAddr; addr != "" {
+ if err := s.AddAddress(nicID, header.IPv6ProtocolNumber, addr); err != nil {
+ t.Fatalf("AddAddress(%d, %d, %s) = %s", nicID, header.IPv6ProtocolNumber, addr, err)
+ }
+ }
- if addr := test.nicAddr; addr != "" {
- if err := s.AddAddress(nicID, header.IPv6ProtocolNumber, addr); err != nil {
- t.Fatalf("AddAddress(%d, %d, %s) = %s", nicID, header.IPv6ProtocolNumber, addr, err)
- }
- }
+ // Make sure each RS is sent at the right time.
+ remaining := test.maxRtrSolicit
+ if remaining > 0 {
+ waitForPkt(test.effectiveMaxRtrSolicitDelay)
+ remaining--
+ }
- // Make sure each RS is sent at the right time.
- remaining := test.maxRtrSolicit
- if remaining > 0 {
- waitForPkt(test.effectiveMaxRtrSolicitDelay)
- remaining--
- }
+ subTest.afterFirstRS(t, s)
- for ; remaining > 0; remaining-- {
- if test.effectiveRtrSolicitInt > defaultAsyncPositiveEventTimeout {
- waitForNothing(test.effectiveRtrSolicitInt - time.Nanosecond)
- waitForPkt(time.Nanosecond)
- } else {
- waitForPkt(test.effectiveRtrSolicitInt)
- }
- }
+ for ; remaining > 0; remaining-- {
+ if test.effectiveRtrSolicitInt > defaultAsyncPositiveEventTimeout {
+ waitForNothing(test.effectiveRtrSolicitInt - time.Nanosecond)
+ waitForPkt(time.Nanosecond)
+ } else {
+ waitForPkt(test.effectiveRtrSolicitInt)
+ }
+ }
- // Make sure no more RS.
- if test.effectiveRtrSolicitInt > test.effectiveMaxRtrSolicitDelay {
- waitForNothing(test.effectiveRtrSolicitInt)
- } else {
- waitForNothing(test.effectiveMaxRtrSolicitDelay)
- }
+ // Make sure no more RS.
+ if test.effectiveRtrSolicitInt > test.effectiveMaxRtrSolicitDelay {
+ waitForNothing(test.effectiveRtrSolicitInt)
+ } else {
+ waitForNothing(test.effectiveMaxRtrSolicitDelay)
+ }
- if got, want := s.Stats().ICMP.V6.PacketsSent.RouterSolicit.Value(), uint64(test.maxRtrSolicit); got != want {
- t.Fatalf("got sent RouterSolicit = %d, want = %d", got, want)
+ if got, want := s.Stats().ICMP.V6.PacketsSent.RouterSolicit.Value(), uint64(test.maxRtrSolicit); got != want {
+ t.Fatalf("got sent RouterSolicit = %d, want = %d", got, want)
+ }
+ })
}
})
}
@@ -5486,6 +5554,7 @@ func TestStopStartSolicitingRouters(t *testing.T) {
s := stack.New(stack.Options{
NetworkProtocols: []stack.NetworkProtocolFactory{ipv6.NewProtocolWithOptions(ipv6.Options{
NDPConfigs: ipv6.NDPConfigurations{
+ HandleRAs: ipv6.HandlingRAsEnabledWhenForwardingDisabled,
MaxRtrSolicitations: maxRtrSolicitations,
RtrSolicitationInterval: interval,
MaxRtrSolicitationDelay: delay,
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-03 21:05:07 +0000