diff options
| -rw-r--r-- | pkg/tcpip/network/ipv6/ipv6.go | 5 | ||||
| -rw-r--r-- | pkg/tcpip/network/ipv6/ndp.go | 145 | ||||
| -rw-r--r-- | pkg/tcpip/network/ipv6/ndp_test.go | 2 | ||||
| -rw-r--r-- | pkg/tcpip/stack/ndp_test.go | 6 |
4 files changed, 80 insertions, 78 deletions
diff --git a/pkg/tcpip/network/ipv6/ipv6.go b/pkg/tcpip/network/ipv6/ipv6.go index f5693defe..b1aec5312 100644 --- a/pkg/tcpip/network/ipv6/ipv6.go +++ b/pkg/tcpip/network/ipv6/ipv6.go @@ -344,7 +344,10 @@ func (e *endpoint) onAddressAssignedLocked(addr tcpip.Address) { func (e *endpoint) InvalidateDefaultRouter(rtr tcpip.Address) { e.mu.Lock() defer e.mu.Unlock() - e.mu.ndp.invalidateDefaultRouter(rtr) + + // We represent default routers with a default (off-link) route through the + // router. + e.mu.ndp.invalidateOffLinkRoute(offLinkRoute{dest: header.IPv6EmptySubnet, router: rtr}) } // SetNDPConfigurations implements NDPEndpoint. diff --git a/pkg/tcpip/network/ipv6/ndp.go b/pkg/tcpip/network/ipv6/ndp.go index c44e4ac4e..9cd283eba 100644 --- a/pkg/tcpip/network/ipv6/ndp.go +++ b/pkg/tcpip/network/ipv6/ndp.go @@ -78,13 +78,13 @@ const ( // we cannot have a negative delay. minimumMaxRtrSolicitationDelay = 0 - // MaxDiscoveredDefaultRouters is the maximum number of discovered - // default routers. The stack should stop discovering new routers after - // discovering MaxDiscoveredDefaultRouters routers. + // MaxDiscoveredOffLinkRoutes is the maximum number of discovered off-link + // routes. The stack should stop discovering new off-link routes after + // this limit is reached. // // This value MUST be at minimum 2 as per RFC 4861 section 6.3.4, and // SHOULD be more. - MaxDiscoveredDefaultRouters = 10 + MaxDiscoveredOffLinkRoutes = 10 // MaxDiscoveredOnLinkPrefixes is the maximum number of discovered // on-link prefixes. The stack should stop discovering new on-link @@ -448,6 +448,11 @@ type timer struct { timer tcpip.Timer } +type offLinkRoute struct { + dest tcpip.Subnet + router tcpip.Address +} + // ndpState is the per-Interface NDP state. type ndpState struct { // Do not allow overwriting this state. @@ -462,8 +467,8 @@ type ndpState struct { // The DAD timers to send the next NS message, or resolve the address. dad ip.DAD - // The default routers discovered through Router Advertisements. - defaultRouters map[tcpip.Address]defaultRouterState + // The off-link routes discovered through Router Advertisements. + offLinkRoutes map[offLinkRoute]offLinkRouteState // rtrSolicitTimer is the timer used to send the next router solicitation // message. @@ -491,12 +496,12 @@ type ndpState struct { temporaryAddressDesyncFactor time.Duration } -// defaultRouterState holds data associated with a default router discovered by +// offLinkRouteState holds data associated with an off-link route discovered by // a Router Advertisement (RA). -type defaultRouterState struct { +type offLinkRouteState struct { prf header.NDPRoutePreference - // Job to invalidate the default router. + // Job to invalidate the route. // // Must not be nil. invalidationJob *tcpip.Job @@ -727,38 +732,9 @@ func (ndp *ndpState) handleRA(ip tcpip.Address, ra header.NDPRouterAdvert) { prf = header.MediumRoutePreference } - rtr, ok := ndp.defaultRouters[ip] - rl := ra.RouterLifetime() - switch { - case !ok && rl != 0: - // This is a new default router we are discovering. - // - // Only remember it if we currently know about less than - // MaxDiscoveredDefaultRouters routers. - if len(ndp.defaultRouters) < MaxDiscoveredDefaultRouters { - ndp.rememberDefaultRouter(ip, rl, prf) - } - - case ok && rl != 0: - // This is an already discovered default router. Update - // the invalidation job. - rtr.invalidationJob.Cancel() - rtr.invalidationJob.Schedule(rl) - - if prf != rtr.prf { - rtr.prf = prf - - // Inform the integrator about router preference updates. - ndp.ep.protocol.options.NDPDisp.OnOffLinkRouteUpdated(ndp.ep.nic.ID(), header.IPv6EmptySubnet, ip, prf) - } - - ndp.defaultRouters[ip] = rtr - - case ok && rl == 0: - // We know about the router but it is no longer to be - // used as a default router so invalidate it. - ndp.invalidateDefaultRouter(ip) - } + // We represent default routers with a default (off-link) route through the + // router. + ndp.handleOffLinkRouteDiscovery(offLinkRoute{dest: header.IPv6EmptySubnet, router: ip}, ra.RouterLifetime(), prf) } // TODO(b/141556115): Do (RetransTimer, ReachableTime)) Parameter @@ -816,52 +792,75 @@ func (ndp *ndpState) handleRA(ip tcpip.Address, ra header.NDPRouterAdvert) { } } -// invalidateDefaultRouter invalidates a discovered default router. +// invalidateOffLinkRoute invalidates a discovered off-link route. // // The IPv6 endpoint that ndp belongs to MUST be locked. -func (ndp *ndpState) invalidateDefaultRouter(ip tcpip.Address) { - rtr, ok := ndp.defaultRouters[ip] - - // Is the router still discovered? +func (ndp *ndpState) invalidateOffLinkRoute(route offLinkRoute) { + state, ok := ndp.offLinkRoutes[route] if !ok { - // ...Nope, do nothing further. return } - rtr.invalidationJob.Cancel() - delete(ndp.defaultRouters, ip) + state.invalidationJob.Cancel() + delete(ndp.offLinkRoutes, route) - // Let the integrator know a discovered default router is invalidated. + // Let the integrator know a discovered off-link route is invalidated. if ndpDisp := ndp.ep.protocol.options.NDPDisp; ndpDisp != nil { - ndpDisp.OnOffLinkRouteInvalidated(ndp.ep.nic.ID(), header.IPv6EmptySubnet, ip) + ndpDisp.OnOffLinkRouteInvalidated(ndp.ep.nic.ID(), route.dest, route.router) } } -// rememberDefaultRouter remembers a newly discovered default router with IPv6 -// link-local address ip with lifetime rl. -// -// The router identified by ip MUST NOT already be known by the IPv6 endpoint. +// handleOffLinkRouteDiscovery handles the discovery of an off-link route. // -// The IPv6 endpoint that ndp belongs to MUST be locked. -func (ndp *ndpState) rememberDefaultRouter(ip tcpip.Address, rl time.Duration, prf header.NDPRoutePreference) { +// Precondition: ndp.ep.mu must be locked. +func (ndp *ndpState) handleOffLinkRouteDiscovery(route offLinkRoute, lifetime time.Duration, prf header.NDPRoutePreference) { ndpDisp := ndp.ep.protocol.options.NDPDisp if ndpDisp == nil { return } - // Inform the integrator when we discovered a default router. - ndpDisp.OnOffLinkRouteUpdated(ndp.ep.nic.ID(), header.IPv6EmptySubnet, ip, prf) + state, ok := ndp.offLinkRoutes[route] + switch { + case !ok && lifetime != 0: + // This is a new route we are discovering. + // + // Only remember it if we currently know about less than + // MaxDiscoveredOffLinkRoutes routers. + if len(ndp.offLinkRoutes) < MaxDiscoveredOffLinkRoutes { + // Inform the integrator when we discovered an off-link route. + ndpDisp.OnOffLinkRouteUpdated(ndp.ep.nic.ID(), route.dest, route.router, prf) + + state := offLinkRouteState{ + prf: prf, + invalidationJob: ndp.ep.protocol.stack.NewJob(&ndp.ep.mu, func() { + ndp.invalidateOffLinkRoute(route) + }), + } - state := defaultRouterState{ - prf: prf, - invalidationJob: ndp.ep.protocol.stack.NewJob(&ndp.ep.mu, func() { - ndp.invalidateDefaultRouter(ip) - }), - } + state.invalidationJob.Schedule(lifetime) - state.invalidationJob.Schedule(rl) + ndp.offLinkRoutes[route] = state + } + + case ok && lifetime != 0: + // This is an already discovered off-link route. Update the lifetime. + state.invalidationJob.Cancel() + state.invalidationJob.Schedule(lifetime) - ndp.defaultRouters[ip] = state + if prf != state.prf { + state.prf = prf + + // Inform the integrator about route preference updates. + ndpDisp.OnOffLinkRouteUpdated(ndp.ep.nic.ID(), route.dest, route.router, prf) + } + + ndp.offLinkRoutes[route] = state + + case ok && lifetime == 0: + // The already discovered off-link route is no longer considered valid so we + // invalidate it immediately. + ndp.invalidateOffLinkRoute(route) + } } // rememberOnLinkPrefix remembers a newly discovered on-link prefix with IPv6 @@ -1677,12 +1676,12 @@ func (ndp *ndpState) cleanupState() { panic(fmt.Sprintf("ndp: still have discovered on-link prefixes after cleaning up; found = %d", got)) } - for router := range ndp.defaultRouters { - ndp.invalidateDefaultRouter(router) + for route := range ndp.offLinkRoutes { + ndp.invalidateOffLinkRoute(route) } - if got := len(ndp.defaultRouters); got != 0 { - panic(fmt.Sprintf("ndp: still have discovered default routers after cleaning up; found = %d", got)) + if got := len(ndp.offLinkRoutes); got != 0 { + panic(fmt.Sprintf("ndp: still have discovered off-link routes after cleaning up; found = %d", got)) } ndp.dhcpv6Configuration = 0 @@ -1845,14 +1844,14 @@ func (ndp *ndpState) stopSolicitingRouters() { } func (ndp *ndpState) init(ep *endpoint, dadOptions ip.DADOptions) { - if ndp.defaultRouters != nil { + if ndp.offLinkRoutes != nil { panic("attempted to initialize NDP state twice") } ndp.ep = ep ndp.configs = ep.protocol.options.NDPConfigs ndp.dad.Init(&ndp.ep.mu, ep.protocol.options.DADConfigs, dadOptions) - ndp.defaultRouters = make(map[tcpip.Address]defaultRouterState) + ndp.offLinkRoutes = make(map[offLinkRoute]offLinkRouteState) ndp.onLinkPrefixes = make(map[tcpip.Subnet]onLinkPrefixState) ndp.slaacPrefixes = make(map[tcpip.Subnet]slaacPrefixState) diff --git a/pkg/tcpip/network/ipv6/ndp_test.go b/pkg/tcpip/network/ipv6/ndp_test.go index 130438f3b..f0186c64e 100644 --- a/pkg/tcpip/network/ipv6/ndp_test.go +++ b/pkg/tcpip/network/ipv6/ndp_test.go @@ -93,7 +93,7 @@ func TestStackNDPEndpointInvalidateDefaultRouter(t *testing.T) { ipv6EP := ep.(*endpoint) ipv6EP.mu.Lock() - ipv6EP.mu.ndp.rememberDefaultRouter(lladdr1, time.Hour, header.MediumRoutePreference) + ipv6EP.mu.ndp.handleOffLinkRouteDiscovery(offLinkRoute{dest: header.IPv6EmptySubnet, router: lladdr1}, time.Hour, header.MediumRoutePreference) ipv6EP.mu.Unlock() if ndpDisp.addr != lladdr1 { diff --git a/pkg/tcpip/stack/ndp_test.go b/pkg/tcpip/stack/ndp_test.go index bd512d312..9623d9c28 100644 --- a/pkg/tcpip/stack/ndp_test.go +++ b/pkg/tcpip/stack/ndp_test.go @@ -1461,7 +1461,7 @@ func TestRouterDiscovery(t *testing.T) { } // TestRouterDiscoveryMaxRouters tests that only -// ipv6.MaxDiscoveredDefaultRouters discovered routers are remembered. +// ipv6.MaxDiscoveredOffLinkRoutes discovered routers are remembered. func TestRouterDiscoveryMaxRouters(t *testing.T) { const nicID = 1 @@ -1484,14 +1484,14 @@ func TestRouterDiscoveryMaxRouters(t *testing.T) { } // Receive an RA from 2 more than the max number of discovered routers. - for i := 1; i <= ipv6.MaxDiscoveredDefaultRouters+2; i++ { + for i := 1; i <= ipv6.MaxDiscoveredOffLinkRoutes+2; i++ { linkAddr := []byte{2, 2, 3, 4, 5, 0} linkAddr[5] = byte(i) llAddr := header.LinkLocalAddr(tcpip.LinkAddress(linkAddr)) e.InjectInbound(header.IPv6ProtocolNumber, raBufSimple(llAddr, 5)) - if i <= ipv6.MaxDiscoveredDefaultRouters { + if i <= ipv6.MaxDiscoveredOffLinkRoutes { select { case e := <-ndpDisp.offLinkRouteC: if diff := checkOffLinkRouteEvent(e, nicID, llAddr, header.MediumRoutePreference, true); diff != "" { |