diff options
| -rw-r--r-- | pkg/tcpip/stack/ndp.go | 35 | ||||
| -rw-r--r-- | pkg/tcpip/stack/ndp_test.go | 283 | ||||
| -rw-r--r-- | pkg/tcpip/stack/nic.go | 12 | ||||
| -rw-r--r-- | pkg/tcpip/stack/stack.go | 22 |
4 files changed, 338 insertions, 14 deletions
diff --git a/pkg/tcpip/stack/ndp.go b/pkg/tcpip/stack/ndp.go index 90664ba8a..d9ab59336 100644 --- a/pkg/tcpip/stack/ndp.go +++ b/pkg/tcpip/stack/ndp.go @@ -1155,3 +1155,38 @@ func (ndp *ndpState) autoGenAddrInvalidationTimer(addr tcpip.Address, vl time.Du ndp.invalidateAutoGenAddress(addr) }) } + +// cleanupHostOnlyState cleans up any state that is only useful for hosts. +// +// cleanupHostOnlyState MUST be called when ndp's NIC is transitioning from a +// host to a router. This function will invalidate all discovered on-link +// prefixes, discovered routers, and auto-generated addresses as routers do not +// normally process Router Advertisements to discover default routers and +// on-link prefixes, and auto-generate addresses via SLAAC. +// +// The NIC that ndp belongs to MUST be locked. +func (ndp *ndpState) cleanupHostOnlyState() { + for addr, _ := range ndp.autoGenAddresses { + ndp.invalidateAutoGenAddress(addr) + } + + if got := len(ndp.autoGenAddresses); got != 0 { + log.Fatalf("ndp: still have auto-generated addresses after cleaning up, found = %d", got) + } + + for prefix, _ := range ndp.onLinkPrefixes { + ndp.invalidateOnLinkPrefix(prefix) + } + + if got := len(ndp.onLinkPrefixes); got != 0 { + log.Fatalf("ndp: still have discovered on-link prefixes after cleaning up, found = %d", got) + } + + for router, _ := range ndp.defaultRouters { + ndp.invalidateDefaultRouter(router) + } + + if got := len(ndp.defaultRouters); got != 0 { + log.Fatalf("ndp: still have discovered default routers after cleaning up, found = %d", got) + } +} diff --git a/pkg/tcpip/stack/ndp_test.go b/pkg/tcpip/stack/ndp_test.go index 666f86c33..64a9a2b20 100644 --- a/pkg/tcpip/stack/ndp_test.go +++ b/pkg/tcpip/stack/ndp_test.go @@ -47,6 +47,19 @@ var ( llAddr3 = header.LinkLocalAddr(linkAddr3) ) +func addrForSubnet(subnet tcpip.Subnet, linkAddr tcpip.LinkAddress) tcpip.AddressWithPrefix { + if !header.IsValidUnicastEthernetAddress(linkAddr) { + return tcpip.AddressWithPrefix{} + } + + addrBytes := []byte(subnet.ID()) + header.EthernetAdddressToModifiedEUI64IntoBuf(linkAddr, addrBytes[header.IIDOffsetInIPv6Address:]) + return tcpip.AddressWithPrefix{ + Address: tcpip.Address(addrBytes), + PrefixLen: 64, + } +} + // prefixSubnetAddr returns a prefix (Address + Length), the prefix's equivalent // tcpip.Subnet, and an address where the lower half of the address is composed // of the EUI-64 of linkAddr if it is a valid unicast ethernet address. @@ -59,17 +72,7 @@ func prefixSubnetAddr(offset uint8, linkAddr tcpip.LinkAddress) (tcpip.AddressWi subnet := prefix.Subnet() - var addr tcpip.AddressWithPrefix - if header.IsValidUnicastEthernetAddress(linkAddr) { - addrBytes := []byte(subnet.ID()) - header.EthernetAdddressToModifiedEUI64IntoBuf(linkAddr, addrBytes[header.IIDOffsetInIPv6Address:]) - addr = tcpip.AddressWithPrefix{ - Address: tcpip.Address(addrBytes), - PrefixLen: 64, - } - } - - return prefix, subnet, addr + return prefix, subnet, addrForSubnet(subnet, linkAddr) } // TestDADDisabled tests that an address successfully resolves immediately @@ -1772,7 +1775,7 @@ func TestAutoGenAddrValidLifetimeUpdates(t *testing.T) { // test.evl. select { case <-ndpDisp.autoGenAddrC: - t.Fatalf("unexpectedly received an auto gen addr event") + t.Fatal("unexpectedly received an auto gen addr event") case <-time.After(time.Duration(test.evl)*time.Second - delta): } @@ -1846,7 +1849,7 @@ func TestAutoGenAddrRemoval(t *testing.T) { // got stopped/cleaned up. select { case <-ndpDisp.autoGenAddrC: - t.Fatalf("unexpectedly received an auto gen addr event") + t.Fatal("unexpectedly received an auto gen addr event") case <-time.After(lifetimeSeconds*time.Second + defaultTimeout): } } @@ -2055,3 +2058,257 @@ func TestNDPRecursiveDNSServerDispatch(t *testing.T) { }) } } + +// TestCleanupHostOnlyStateOnBecomingRouter tests that all discovered routers +// and prefixes, and auto-generated addresses get invalidated when a NIC +// becomes a router. +func TestCleanupHostOnlyStateOnBecomingRouter(t *testing.T) { + t.Parallel() + + const ( + lifetimeSeconds = 5 + maxEvents = 4 + nicID1 = 1 + nicID2 = 2 + ) + + prefix1, subnet1, e1Addr1 := prefixSubnetAddr(0, linkAddr1) + prefix2, subnet2, e1Addr2 := prefixSubnetAddr(1, linkAddr1) + e2Addr1 := addrForSubnet(subnet1, linkAddr2) + e2Addr2 := addrForSubnet(subnet2, linkAddr2) + + ndpDisp := ndpDispatcher{ + routerC: make(chan ndpRouterEvent, maxEvents), + rememberRouter: true, + prefixC: make(chan ndpPrefixEvent, maxEvents), + rememberPrefix: true, + autoGenAddrC: make(chan ndpAutoGenAddrEvent, maxEvents), + } + s := stack.New(stack.Options{ + NetworkProtocols: []stack.NetworkProtocol{ipv6.NewProtocol()}, + NDPConfigs: stack.NDPConfigurations{ + HandleRAs: true, + DiscoverDefaultRouters: true, + DiscoverOnLinkPrefixes: true, + AutoGenGlobalAddresses: true, + }, + NDPDisp: &ndpDisp, + }) + + e1 := channel.New(0, 1280, linkAddr1) + if err := s.CreateNIC(nicID1, e1); err != nil { + t.Fatalf("CreateNIC(%d, _) = %s", nicID1, err) + } + + e2 := channel.New(0, 1280, linkAddr2) + if err := s.CreateNIC(nicID2, e2); err != nil { + t.Fatalf("CreateNIC(%d, _) = %s", nicID2, err) + } + + expectRouterEvent := func() (bool, ndpRouterEvent) { + select { + case e := <-ndpDisp.routerC: + return true, e + default: + } + + return false, ndpRouterEvent{} + } + + expectPrefixEvent := func() (bool, ndpPrefixEvent) { + select { + case e := <-ndpDisp.prefixC: + return true, e + default: + } + + return false, ndpPrefixEvent{} + } + + expectAutoGenAddrEvent := func() (bool, ndpAutoGenAddrEvent) { + select { + case e := <-ndpDisp.autoGenAddrC: + return true, e + default: + } + + return false, ndpAutoGenAddrEvent{} + } + + // Receive RAs on NIC(1) and NIC(2) from default routers (llAddr1 and + // llAddr2) w/ PI (for prefix1 in RA from llAddr1 and prefix2 in RA from + // llAddr2) to discover multiple routers and prefixes, and auto-gen + // multiple addresses. + + e1.InjectInbound(header.IPv6ProtocolNumber, raBufWithPI(llAddr1, lifetimeSeconds, prefix1, true, true, lifetimeSeconds, lifetimeSeconds)) + // We have other tests that make sure we receive the *correct* events + // on normal discovery of routers/prefixes, and auto-generated + // addresses. Here we just make sure we get an event and let other tests + // handle the correctness check. + if ok, _ := expectRouterEvent(); !ok { + t.Errorf("expected router event for %s on NIC(%d)", llAddr1, nicID1) + } + if ok, _ := expectPrefixEvent(); !ok { + t.Errorf("expected prefix event for %s on NIC(%d)", prefix1, nicID1) + } + if ok, _ := expectAutoGenAddrEvent(); !ok { + t.Errorf("expected auto-gen addr event for %s on NIC(%d)", e1Addr1, nicID1) + } + + e1.InjectInbound(header.IPv6ProtocolNumber, raBufWithPI(llAddr2, lifetimeSeconds, prefix2, true, true, lifetimeSeconds, lifetimeSeconds)) + if ok, _ := expectRouterEvent(); !ok { + t.Errorf("expected router event for %s on NIC(%d)", llAddr2, nicID1) + } + if ok, _ := expectPrefixEvent(); !ok { + t.Errorf("expected prefix event for %s on NIC(%d)", prefix2, nicID1) + } + if ok, _ := expectAutoGenAddrEvent(); !ok { + t.Errorf("expected auto-gen addr event for %s on NIC(%d)", e1Addr2, nicID1) + } + + e2.InjectInbound(header.IPv6ProtocolNumber, raBufWithPI(llAddr1, lifetimeSeconds, prefix1, true, true, lifetimeSeconds, lifetimeSeconds)) + if ok, _ := expectRouterEvent(); !ok { + t.Errorf("expected router event for %s on NIC(%d)", llAddr1, nicID2) + } + if ok, _ := expectPrefixEvent(); !ok { + t.Errorf("expected prefix event for %s on NIC(%d)", prefix1, nicID2) + } + if ok, _ := expectAutoGenAddrEvent(); !ok { + t.Errorf("expected auto-gen addr event for %s on NIC(%d)", e1Addr2, nicID2) + } + + e2.InjectInbound(header.IPv6ProtocolNumber, raBufWithPI(llAddr2, lifetimeSeconds, prefix2, true, true, lifetimeSeconds, lifetimeSeconds)) + if ok, _ := expectRouterEvent(); !ok { + t.Errorf("expected router event for %s on NIC(%d)", llAddr2, nicID2) + } + if ok, _ := expectPrefixEvent(); !ok { + t.Errorf("expected prefix event for %s on NIC(%d)", prefix2, nicID2) + } + if ok, _ := expectAutoGenAddrEvent(); !ok { + t.Errorf("expected auto-gen addr event for %s on NIC(%d)", e2Addr2, nicID2) + } + + // We should have the auto-generated addresses added. + nicinfo := s.NICInfo() + nic1Addrs := nicinfo[nicID1].ProtocolAddresses + nic2Addrs := nicinfo[nicID2].ProtocolAddresses + if !contains(nic1Addrs, e1Addr1) { + t.Errorf("missing %s from the list of addresses for NIC(%d): %+v", e1Addr1, nicID1, nic1Addrs) + } + if !contains(nic1Addrs, e1Addr2) { + t.Errorf("missing %s from the list of addresses for NIC(%d): %+v", e1Addr2, nicID1, nic1Addrs) + } + if !contains(nic2Addrs, e2Addr1) { + t.Errorf("missing %s from the list of addresses for NIC(%d): %+v", e2Addr1, nicID2, nic2Addrs) + } + if !contains(nic2Addrs, e2Addr2) { + t.Errorf("missing %s from the list of addresses for NIC(%d): %+v", e2Addr2, nicID2, nic2Addrs) + } + + // We can't proceed any further if we already failed the test (missing + // some discovery/auto-generated address events or addresses). + if t.Failed() { + t.FailNow() + } + + s.SetForwarding(true) + + // Collect invalidation events after becoming a router + gotRouterEvents := make(map[ndpRouterEvent]int) + for i := 0; i < maxEvents; i++ { + ok, e := expectRouterEvent() + if !ok { + t.Errorf("expected %d router events after becoming a router; got = %d", maxEvents, i) + break + } + gotRouterEvents[e]++ + } + gotPrefixEvents := make(map[ndpPrefixEvent]int) + for i := 0; i < maxEvents; i++ { + ok, e := expectPrefixEvent() + if !ok { + t.Errorf("expected %d prefix events after becoming a router; got = %d", maxEvents, i) + break + } + gotPrefixEvents[e]++ + } + gotAutoGenAddrEvents := make(map[ndpAutoGenAddrEvent]int) + for i := 0; i < maxEvents; i++ { + ok, e := expectAutoGenAddrEvent() + if !ok { + t.Errorf("expected %d auto-generated address events after becoming a router; got = %d", maxEvents, i) + break + } + gotAutoGenAddrEvents[e]++ + } + + // No need to proceed any further if we already failed the test (missing + // some invalidation events). + if t.Failed() { + t.FailNow() + } + + expectedRouterEvents := map[ndpRouterEvent]int{ + {nicID: nicID1, addr: llAddr1, discovered: false}: 1, + {nicID: nicID1, addr: llAddr2, discovered: false}: 1, + {nicID: nicID2, addr: llAddr1, discovered: false}: 1, + {nicID: nicID2, addr: llAddr2, discovered: false}: 1, + } + if diff := cmp.Diff(expectedRouterEvents, gotRouterEvents); diff != "" { + t.Errorf("router events mismatch (-want +got):\n%s", diff) + } + expectedPrefixEvents := map[ndpPrefixEvent]int{ + {nicID: nicID1, prefix: subnet1, discovered: false}: 1, + {nicID: nicID1, prefix: subnet2, discovered: false}: 1, + {nicID: nicID2, prefix: subnet1, discovered: false}: 1, + {nicID: nicID2, prefix: subnet2, discovered: false}: 1, + } + if diff := cmp.Diff(expectedPrefixEvents, gotPrefixEvents); diff != "" { + t.Errorf("prefix events mismatch (-want +got):\n%s", diff) + } + expectedAutoGenAddrEvents := map[ndpAutoGenAddrEvent]int{ + {nicID: nicID1, addr: e1Addr1, eventType: invalidatedAddr}: 1, + {nicID: nicID1, addr: e1Addr2, eventType: invalidatedAddr}: 1, + {nicID: nicID2, addr: e2Addr1, eventType: invalidatedAddr}: 1, + {nicID: nicID2, addr: e2Addr2, eventType: invalidatedAddr}: 1, + } + if diff := cmp.Diff(expectedAutoGenAddrEvents, gotAutoGenAddrEvents); diff != "" { + t.Errorf("auto-generated address events mismatch (-want +got):\n%s", diff) + } + + // Make sure the auto-generated addresses got removed. + nicinfo = s.NICInfo() + nic1Addrs = nicinfo[nicID1].ProtocolAddresses + nic2Addrs = nicinfo[nicID2].ProtocolAddresses + if contains(nic1Addrs, e1Addr1) { + t.Errorf("still have %s in the list of addresses for NIC(%d): %+v", e1Addr1, nicID1, nic1Addrs) + } + if contains(nic1Addrs, e1Addr2) { + t.Errorf("still have %s in the list of addresses for NIC(%d): %+v", e1Addr2, nicID1, nic1Addrs) + } + if contains(nic2Addrs, e2Addr1) { + t.Errorf("still have %s in the list of addresses for NIC(%d): %+v", e2Addr1, nicID2, nic2Addrs) + } + if contains(nic2Addrs, e2Addr2) { + t.Errorf("still have %s in the list of addresses for NIC(%d): %+v", e2Addr2, nicID2, nic2Addrs) + } + + // Should not get any more events (invalidation timers should have been + // cancelled when we transitioned into a router). + time.Sleep(lifetimeSeconds*time.Second + defaultTimeout) + select { + case <-ndpDisp.routerC: + t.Error("unexpected router event") + default: + } + select { + case <-ndpDisp.prefixC: + t.Error("unexpected prefix event") + default: + } + select { + case <-ndpDisp.autoGenAddrC: + t.Error("unexpected auto-generated address event") + default: + } +} diff --git a/pkg/tcpip/stack/nic.go b/pkg/tcpip/stack/nic.go index e8401c673..ddd014658 100644 --- a/pkg/tcpip/stack/nic.go +++ b/pkg/tcpip/stack/nic.go @@ -203,6 +203,18 @@ func (n *NIC) enable() *tcpip.Error { return err } +// becomeIPv6Router transitions n into an IPv6 router. +// +// When transitioning into an IPv6 router, host-only state (NDP discovered +// routers, discovered on-link prefixes, and auto-generated addresses) will +// be cleaned up/invalidated. +func (n *NIC) becomeIPv6Router() { + n.mu.Lock() + defer n.mu.Unlock() + + n.ndp.cleanupHostOnlyState() +} + // attachLinkEndpoint attaches the NIC to the endpoint, which will enable it // to start delivering packets. func (n *NIC) attachLinkEndpoint() { diff --git a/pkg/tcpip/stack/stack.go b/pkg/tcpip/stack/stack.go index 0e88643a4..7a9600679 100644 --- a/pkg/tcpip/stack/stack.go +++ b/pkg/tcpip/stack/stack.go @@ -662,11 +662,31 @@ func (s *Stack) Stats() tcpip.Stats { } // SetForwarding enables or disables the packet forwarding between NICs. +// +// When forwarding becomes enabled, any host-only state on all NICs will be +// cleaned up. func (s *Stack) SetForwarding(enable bool) { // TODO(igudger, bgeffon): Expose via /proc/sys/net/ipv4/ip_forward. s.mu.Lock() + defer s.mu.Unlock() + + // If forwarding status didn't change, do nothing further. + if s.forwarding == enable { + return + } + s.forwarding = enable - s.mu.Unlock() + + // If this stack does not support IPv6, do nothing further. + if _, ok := s.networkProtocols[header.IPv6ProtocolNumber]; !ok { + return + } + + if enable { + for _, nic := range s.nics { + nic.becomeIPv6Router() + } + } } // Forwarding returns if the packet forwarding between NICs is enabled. |