diff options
| -rw-r--r-- | pkg/tcpip/header/ipv6.go | 49 | ||||
| -rw-r--r-- | pkg/tcpip/header/ndp_options.go | 9 | ||||
| -rw-r--r-- | pkg/tcpip/stack/ndp.go | 509 | ||||
| -rw-r--r-- | pkg/tcpip/stack/ndp_test.go | 616 | ||||
| -rw-r--r-- | pkg/tcpip/stack/nic.go | 74 |
5 files changed, 1109 insertions, 148 deletions
diff --git a/pkg/tcpip/header/ipv6.go b/pkg/tcpip/header/ipv6.go index 0caa51c1e..5275b34d4 100644 --- a/pkg/tcpip/header/ipv6.go +++ b/pkg/tcpip/header/ipv6.go @@ -90,6 +90,18 @@ const ( // IPv6Any is the non-routable IPv6 "any" meta address. It is also // known as the unspecified address. IPv6Any tcpip.Address = "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" + + // IIDSize is the size of an interface identifier (IID), in bytes, as + // defined by RFC 4291 section 2.5.1. + IIDSize = 8 + + // IIDOffsetInIPv6Address is the offset, in bytes, from the start + // of an IPv6 address to the beginning of the interface identifier + // (IID) for auto-generated addresses. That is, all bytes before + // the IIDOffsetInIPv6Address-th byte are the prefix bytes, and all + // bytes including and after the IIDOffsetInIPv6Address-th byte are + // for the IID. + IIDOffsetInIPv6Address = 8 ) // IPv6EmptySubnet is the empty IPv6 subnet. It may also be known as the @@ -266,6 +278,28 @@ func SolicitedNodeAddr(addr tcpip.Address) tcpip.Address { return solicitedNodeMulticastPrefix + addr[len(addr)-3:] } +// EthernetAdddressToEUI64IntoBuf populates buf with a EUI-64 from a 48-bit +// Ethernet/MAC address. +// +// buf MUST be at least 8 bytes. +func EthernetAdddressToEUI64IntoBuf(linkAddr tcpip.LinkAddress, buf []byte) { + buf[0] = linkAddr[0] ^ 2 + buf[1] = linkAddr[1] + buf[2] = linkAddr[2] + buf[3] = 0xFE + buf[4] = 0xFE + buf[5] = linkAddr[3] + buf[6] = linkAddr[4] + buf[7] = linkAddr[5] +} + +// EthernetAddressToEUI64 computes an EUI-64 from a 48-bit Ethernet/MAC address. +func EthernetAddressToEUI64(linkAddr tcpip.LinkAddress) [IIDSize]byte { + var buf [IIDSize]byte + EthernetAdddressToEUI64IntoBuf(linkAddr, buf[:]) + return buf +} + // LinkLocalAddr computes the default IPv6 link-local address from a link-layer // (MAC) address. func LinkLocalAddr(linkAddr tcpip.LinkAddress) tcpip.Address { @@ -275,18 +309,11 @@ func LinkLocalAddr(linkAddr tcpip.LinkAddress) tcpip.Address { // The conversion is very nearly: // aa:bb:cc:dd:ee:ff => FE80::Aabb:ccFF:FEdd:eeff // Note the capital A. The conversion aa->Aa involves a bit flip. - lladdrb := [16]byte{ - 0: 0xFE, - 1: 0x80, - 8: linkAddr[0] ^ 2, - 9: linkAddr[1], - 10: linkAddr[2], - 11: 0xFF, - 12: 0xFE, - 13: linkAddr[3], - 14: linkAddr[4], - 15: linkAddr[5], + lladdrb := [IPv6AddressSize]byte{ + 0: 0xFE, + 1: 0x80, } + EthernetAdddressToEUI64IntoBuf(linkAddr, lladdrb[IIDOffsetInIPv6Address:]) return tcpip.Address(lladdrb[:]) } diff --git a/pkg/tcpip/header/ndp_options.go b/pkg/tcpip/header/ndp_options.go index 2652e7b67..06e0bace2 100644 --- a/pkg/tcpip/header/ndp_options.go +++ b/pkg/tcpip/header/ndp_options.go @@ -17,6 +17,7 @@ package header import ( "encoding/binary" "errors" + "math" "time" "gvisor.dev/gvisor/pkg/tcpip" @@ -109,13 +110,13 @@ const ( ) var ( - // NDPInfiniteLifetime is a value that represents - // infinity for the Valid and Preferred Lifetime fields in a NDP Prefix - // Information option. Its value is (2^32 - 1)s = 4294967295s + // NDPInfiniteLifetime is a value that represents infinity for the + // 4-byte lifetime fields found in various NDP options. Its value is + // (2^32 - 1)s = 4294967295s. // // This is a variable instead of a constant so that tests can change // this value to a smaller value. It should only be modified by tests. - NDPInfiniteLifetime = time.Second * 4294967295 + NDPInfiniteLifetime = time.Second * math.MaxUint32 ) // NDPOptionIterator is an iterator of NDPOption. diff --git a/pkg/tcpip/stack/ndp.go b/pkg/tcpip/stack/ndp.go index 1d202deb5..75d3ecdac 100644 --- a/pkg/tcpip/stack/ndp.go +++ b/pkg/tcpip/stack/ndp.go @@ -58,6 +58,14 @@ const ( // Default = true. defaultDiscoverOnLinkPrefixes = true + // defaultAutoGenGlobalAddresses is the default configuration for + // whether or not to generate global IPv6 addresses in response to + // receiving a new Prefix Information option with its Autonomous + // Address AutoConfiguration flag set, as a host. + // + // Default = true. + defaultAutoGenGlobalAddresses = true + // minimumRetransmitTimer is the minimum amount of time to wait between // sending NDP Neighbor solicitation messages. Note, RFC 4861 does // not impose a minimum Retransmit Timer, but we do here to make sure @@ -87,6 +95,24 @@ const ( // // Max = 10. MaxDiscoveredOnLinkPrefixes = 10 + + // validPrefixLenForAutoGen is the expected prefix length that an + // address can be generated for. Must be 64 bits as the interface + // identifier (IID) is 64 bits and an IPv6 address is 128 bits, so + // 128 - 64 = 64. + validPrefixLenForAutoGen = 64 +) + +var ( + // MinPrefixInformationValidLifetimeForUpdate is the minimum Valid + // Lifetime to update the valid lifetime of a generated address by + // SLAAC. + // + // This is exported as a variable (instead of a constant) so tests + // can update it to a smaller value. + // + // Min = 2hrs. + MinPrefixInformationValidLifetimeForUpdate = 2 * time.Hour ) // NDPDispatcher is the interface integrators of netstack must implement to @@ -139,6 +165,22 @@ type NDPDispatcher interface { // This function is not permitted to block indefinitely. This function // is also not permitted to call into the stack. OnOnLinkPrefixInvalidated(nicID tcpip.NICID, prefix tcpip.Subnet) []tcpip.Route + + // OnAutoGenAddress will be called when a new prefix with its + // autonomous address-configuration flag set has been received and SLAAC + // has been performed. Implementations may prevent the stack from + // assigning the address to the NIC by returning false. + // + // This function is not permitted to block indefinitely. It must not + // call functions on the stack itself. + OnAutoGenAddress(tcpip.NICID, tcpip.AddressWithPrefix) bool + + // OnAutoGenAddressInvalidated will be called when an auto-generated + // address (as part of SLAAC) has been invalidated. + // + // This function is not permitted to block indefinitely. It must not + // call functions on the stack itself. + OnAutoGenAddressInvalidated(tcpip.NICID, tcpip.AddressWithPrefix) } // NDPConfigurations is the NDP configurations for the netstack. @@ -168,6 +210,17 @@ type NDPConfigurations struct { // will be discovered from Router Advertisements' Prefix Information // option. This configuration is ignored if HandleRAs is false. DiscoverOnLinkPrefixes bool + + // AutoGenGlobalAddresses determines whether or not global IPv6 + // addresses will be generated for a NIC in response to receiving a new + // Prefix Information option with its Autonomous Address + // AutoConfiguration flag set, as a host, as per RFC 4862 (SLAAC). + // + // Note, if an address was already generated for some unique prefix, as + // part of SLAAC, this option does not affect whether or not the + // lifetime(s) of the generated address changes; this option only + // affects the generation of new addresses as part of SLAAC. + AutoGenGlobalAddresses bool } // DefaultNDPConfigurations returns an NDPConfigurations populated with @@ -179,6 +232,7 @@ func DefaultNDPConfigurations() NDPConfigurations { HandleRAs: defaultHandleRAs, DiscoverDefaultRouters: defaultDiscoverDefaultRouters, DiscoverOnLinkPrefixes: defaultDiscoverOnLinkPrefixes, + AutoGenGlobalAddresses: defaultAutoGenGlobalAddresses, } } @@ -210,6 +264,9 @@ type ndpState struct { // The on-link prefixes discovered through Router Advertisements' Prefix // Information option. onLinkPrefixes map[tcpip.Subnet]onLinkPrefixState + + // The addresses generated by SLAAC. + autoGenAddresses map[tcpip.Address]autoGenAddressState } // dadState holds the Duplicate Address Detection timer and channel to signal @@ -270,6 +327,32 @@ type onLinkPrefixState struct { doNotInvalidate *bool } +// autoGenAddressState holds data associated with an address generated via +// SLAAC. +type autoGenAddressState struct { + invalidationTimer *time.Timer + + // Used to signal the timer not to invalidate the SLAAC address (A) in + // a race condition (T1 is a goroutine that handles a PI for A and T2 + // is the goroutine that handles A's invalidation timer firing): + // T1: Receive a new PI for A + // T1: Obtain the NIC's lock before processing the PI + // T2: A's invalidation timer fires, and gets blocked on obtaining the + // NIC's lock + // T1: Refreshes/extends A's lifetime & releases NIC's lock + // T2: Obtains NIC's lock & invalidates A immediately + // + // To resolve this, T1 will check to see if the timer already fired, and + // inform the timer using doNotInvalidate to not invalidate A, so that + // once T2 obtains the lock, it will see that it is set to true and do + // nothing further. + doNotInvalidate *bool + + // Nonzero only when the address is not valid forever (invalidationTimer + // is not nil). + validUntil time.Time +} + // startDuplicateAddressDetection performs Duplicate Address Detection. // // This function must only be called by IPv6 addresses that are currently @@ -536,17 +619,14 @@ func (ndp *ndpState) handleRA(ip tcpip.Address, ra header.NDPRouterAdvert) { for opt, done, _ := it.Next(); !done; opt, done, _ = it.Next() { switch opt.Type() { case header.NDPPrefixInformationType: - if !ndp.configs.DiscoverOnLinkPrefixes { - continue - } - pi := opt.(header.NDPPrefixInformation) prefix := pi.Subnet() // Is the prefix a link-local? if header.IsV6LinkLocalAddress(prefix.ID()) { - // ...Yes, skip as per RFC 4861 section 6.3.4. + // ...Yes, skip as per RFC 4861 section 6.3.4, + // and RFC 4862 section 5.5.3.b (for SLAAC). continue } @@ -557,82 +637,13 @@ func (ndp *ndpState) handleRA(ip tcpip.Address, ra header.NDPRouterAdvert) { continue } - if !pi.OnLinkFlag() { - // Not on-link so don't "discover" it as an - // on-link prefix. - continue - } - - prefixState, ok := ndp.onLinkPrefixes[prefix] - vl := pi.ValidLifetime() - switch { - case !ok && vl == 0: - // Don't know about this prefix but has a zero - // valid lifetime, so just ignore. - continue - - case !ok && vl != 0: - // This is a new on-link prefix we are - // discovering. - // - // Only remember it if we currently know about - // less than MaxDiscoveredOnLinkPrefixes on-link - // prefixes. - if len(ndp.onLinkPrefixes) < MaxDiscoveredOnLinkPrefixes { - ndp.rememberOnLinkPrefix(prefix, vl) - } - continue - - case ok && vl == 0: - // We know about the on-link prefix, but it is - // no longer to be considered on-link, so - // invalidate it. - ndp.invalidateOnLinkPrefix(prefix) - continue - } - - // This is an already discovered on-link prefix with a - // new non-zero valid lifetime. - // Update the invalidation timer. - timer := prefixState.invalidationTimer - - if timer == nil && vl >= header.NDPInfiniteLifetime { - // Had infinite valid lifetime before and - // continues to have an invalid lifetime. Do - // nothing further. - continue - } - - if timer != nil && !timer.Stop() { - // If we reach this point, then we know the - // timer already fired after we took the NIC - // lock. Inform the timer to not invalidate - // the prefix once it obtains the lock as we - // just got a new PI that refeshes its lifetime - // to a non-zero value. See - // onLinkPrefixState.doNotInvalidate for more - // details. - *prefixState.doNotInvalidate = true + if pi.OnLinkFlag() { + ndp.handleOnLinkPrefixInformation(pi) } - if vl >= header.NDPInfiniteLifetime { - // Prefix is now valid forever so we don't need - // an invalidation timer. - prefixState.invalidationTimer = nil - ndp.onLinkPrefixes[prefix] = prefixState - continue + if pi.AutonomousAddressConfigurationFlag() { + ndp.handleAutonomousPrefixInformation(pi) } - - if timer != nil { - // We already have a timer so just reset it to - // expire after the new valid lifetime. - timer.Reset(vl) - continue - } - - // We do not have a timer so just create a new one. - prefixState.invalidationTimer = ndp.prefixInvalidationCallback(prefix, vl, prefixState.doNotInvalidate) - ndp.onLinkPrefixes[prefix] = prefixState } // TODO(b/141556115): Do (MTU) Parameter Discovery. @@ -795,3 +806,345 @@ func (ndp *ndpState) prefixInvalidationCallback(prefix tcpip.Subnet, vl time.Dur ndp.invalidateOnLinkPrefix(prefix) }) } + +// handleOnLinkPrefixInformation handles a Prefix Information option with +// its on-link flag set, as per RFC 4861 section 6.3.4. +// +// handleOnLinkPrefixInformation assumes that the prefix this pi is for is +// not the link-local prefix and the on-link flag is set. +// +// The NIC that ndp belongs to and its associated stack MUST be locked. +func (ndp *ndpState) handleOnLinkPrefixInformation(pi header.NDPPrefixInformation) { + prefix := pi.Subnet() + prefixState, ok := ndp.onLinkPrefixes[prefix] + vl := pi.ValidLifetime() + + if !ok && vl == 0 { + // Don't know about this prefix but it has a zero valid + // lifetime, so just ignore. + return + } + + if !ok && vl != 0 { + // This is a new on-link prefix we are discovering + // + // Only remember it if we currently know about less than + // MaxDiscoveredOnLinkPrefixes on-link prefixes. + if ndp.configs.DiscoverOnLinkPrefixes && len(ndp.onLinkPrefixes) < MaxDiscoveredOnLinkPrefixes { + ndp.rememberOnLinkPrefix(prefix, vl) + } + return + } + + if ok && vl == 0 { + // We know about the on-link prefix, but it is + // no longer to be considered on-link, so + // invalidate it. + ndp.invalidateOnLinkPrefix(prefix) + return + } + + // This is an already discovered on-link prefix with a + // new non-zero valid lifetime. + // Update the invalidation timer. + timer := prefixState.invalidationTimer + + if timer == nil && vl >= header.NDPInfiniteLifetime { + // Had infinite valid lifetime before and + // continues to have an invalid lifetime. Do + // nothing further. + return + } + + if timer != nil && !timer.Stop() { + // If we reach this point, then we know the timer alread fired + // after we took the NIC lock. Inform the timer to not + // invalidate the prefix once it obtains the lock as we just + // got a new PI that refreshes its lifetime to a non-zero value. + // See onLinkPrefixState.doNotInvalidate for more details. + *prefixState.doNotInvalidate = true + } + + if vl >= header.NDPInfiniteLifetime { + // Prefix is now valid forever so we don't need + // an invalidation timer. + prefixState.invalidationTimer = nil + ndp.onLinkPrefixes[prefix] = prefixState + return + } + + if timer != nil { + // We already have a timer so just reset it to + // expire after the new valid lifetime. + timer.Reset(vl) + return + } + + // We do not have a timer so just create a new one. + prefixState.invalidationTimer = ndp.prefixInvalidationCallback(prefix, vl, prefixState.doNotInvalidate) + ndp.onLinkPrefixes[prefix] = prefixState +} + +// handleAutonomousPrefixInformation handles a Prefix Information option with +// its autonomous flag set, as per RFC 4862 section 5.5.3. +// +// handleAutonomousPrefixInformation assumes that the prefix this pi is for is +// not the link-local prefix and the autonomous flag is set. +// +// The NIC that ndp belongs to and its associated stack MUST be locked. +func (ndp *ndpState) handleAutonomousPrefixInformation(pi header.NDPPrefixInformation) { + vl := pi.ValidLifetime() + pl := pi.PreferredLifetime() + + // If the preferred lifetime is greater than the valid lifetime, + // silently ignore the Prefix Information option, as per RFC 4862 + // section 5.5.3.c. + if pl > vl { + return + } + + prefix := pi.Subnet() + + // Check if we already have an auto-generated address for prefix. + for _, ref := range ndp.nic.endpoints { + if ref.protocol != header.IPv6ProtocolNumber { + continue + } + + if ref.configType != slaac { + continue + } + + addr := ref.ep.ID().LocalAddress + refAddrWithPrefix := tcpip.AddressWithPrefix{Address: addr, PrefixLen: ref.ep.PrefixLen()} + if refAddrWithPrefix.Subnet() != prefix { + continue + } + + // + // At this point, we know we are refreshing a SLAAC generated + // IPv6 address with the prefix, prefix. Do the work as outlined + // by RFC 4862 section 5.5.3.e. + // + + addrState, ok := ndp.autoGenAddresses[addr] + if !ok { + panic(fmt.Sprintf("must have an autoGenAddressess entry for the SLAAC generated IPv6 address %s", addr)) + } + + // TODO(b/143713887): Handle deprecating auto-generated address + // after the preferred lifetime. + + // As per RFC 4862 section 5.5.3.e, the valid lifetime of the + // address generated by SLAAC is as follows: + // + // 1) If the received Valid Lifetime is greater than 2 hours or + // greater than RemainingLifetime, set the valid lifetime of + // the address to the advertised Valid Lifetime. + // + // 2) If RemainingLifetime is less than or equal to 2 hours, + // ignore the advertised Valid Lifetime. + // + // 3) Otherwise, reset the valid lifetime of the address to 2 + // hours. + + // Handle the infinite valid lifetime separately as we do not + // keep a timer in this case. + if vl >= header.NDPInfiniteLifetime { + if addrState.invalidationTimer != nil { + // Valid lifetime was finite before, but now it + // is valid forever. + if !addrState.invalidationTimer.Stop() { + *addrState.doNotInvalidate = true + } + addrState.invalidationTimer = nil + addrState.validUntil = time.Time{} + ndp.autoGenAddresses[addr] = addrState + } + + return + } + + var effectiveVl time.Duration + var rl time.Duration + + // If the address was originally set to be valid forever, + // assume the remaining time to be the maximum possible value. + if addrState.invalidationTimer == nil { + rl = header.NDPInfiniteLifetime + } else { + rl = time.Until(addrState.validUntil) + } + + if vl > MinPrefixInformationValidLifetimeForUpdate || vl > rl { + effectiveVl = vl + } else if rl <= MinPrefixInformationValidLifetimeForUpdate { + ndp.autoGenAddresses[addr] = addrState + return + } else { + effectiveVl = MinPrefixInformationValidLifetimeForUpdate + } + + if addrState.invalidationTimer == nil { + addrState.invalidationTimer = ndp.autoGenAddrInvalidationTimer(addr, effectiveVl, addrState.doNotInvalidate) + } else { + if !addrState.invalidationTimer.Stop() { + *addrState.doNotInvalidate = true + } + addrState.invalidationTimer.Reset(effectiveVl) + } + + addrState.validUntil = time.Now().Add(effectiveVl) + ndp.autoGenAddresses[addr] = addrState + return + } + + // We do not already have an address within the prefix, prefix. Do the + // work as outlined by RFC 4862 section 5.5.3.d if n is configured + // to auto-generated global addresses by SLAAC. + + // Are we configured to auto-generate new global addresses? + if !ndp.configs.AutoGenGlobalAddresses { + return + } + + // If we do not already have an address for this prefix and the valid + // lifetime is 0, no need to do anything further, as per RFC 4862 + // section 5.5.3.d. + if vl == 0 { + return + } + + // Make sure the prefix is valid (as far as its length is concerned) to + // generate a valid IPv6 address from an interface identifier (IID), as + // per RFC 4862 sectiion 5.5.3.d. + if prefix.Prefix() != validPrefixLenForAutoGen { + return + } + + // Only attempt to generate an interface-specific IID if we have a valid + // link address. + // + // TODO(b/141011931): Validate a LinkEndpoint's link address + // (provided by LinkEndpoint.LinkAddress) before reaching this + // point. + linkAddr := ndp.nic.linkEP.LinkAddress() + if !header.IsValidUnicastEthernetAddress(linkAddr) { + return + } + + // Generate an address within prefix from the EUI-64 of ndp's NIC's + // Ethernet MAC address. + addrBytes := make([]byte, header.IPv6AddressSize) + copy(addrBytes[:header.IIDOffsetInIPv6Address], prefix.ID()[:header.IIDOffsetInIPv6Address]) + header.EthernetAdddressToEUI64IntoBuf(linkAddr, addrBytes[header.IIDOffsetInIPv6Address:]) + addr := tcpip.Address(addrBytes) + addrWithPrefix := tcpip.AddressWithPrefix{ + Address: addr, + PrefixLen: validPrefixLenForAutoGen, + } + + // If the nic already has this address, do nothing further. + if ndp.nic.hasPermanentAddrLocked(addr) { + return + } + + // Inform the integrator that we have a new SLAAC address. + if ndp.nic.stack.ndpDisp == nil { + return + } + if !ndp.nic.stack.ndpDisp.OnAutoGenAddress(ndp.nic.ID(), addrWithPrefix) { + // Informed by the integrator not to add the address. + return + } + + if _, err := ndp.nic.addAddressLocked(tcpip.ProtocolAddress{ + Protocol: header.IPv6ProtocolNumber, + AddressWithPrefix: addrWithPrefix, + }, FirstPrimaryEndpoint, permanent, slaac); err != nil { + panic(err) + } + + // Setup the timers to deprecate and invalidate this newly generated + // address. + + // TODO(b/143713887): Handle deprecating auto-generated addresses + // after the preferred lifetime. + + var doNotInvalidate bool + var vTimer *time.Timer + if vl < header.NDPInfiniteLifetime { + vTimer = ndp.autoGenAddrInvalidationTimer(addr, vl, &doNotInvalidate) + } + + ndp.autoGenAddresses[addr] = autoGenAddressState{ + invalidationTimer: vTimer, + doNotInvalidate: &doNotInvalidate, + validUntil: time.Now().Add(vl), + } +} + +// invalidateAutoGenAddress invalidates an auto-generated address. +// +// The NIC that ndp belongs to MUST be locked. +func (ndp *ndpState) invalidateAutoGenAddress(addr tcpip.Address) { + if !ndp.cleanupAutoGenAddrResourcesAndNotify(addr) { + return + } + + ndp.nic.removePermanentAddressLocked(addr) +} + +// cleanupAutoGenAddrResourcesAndNotify cleans up an invalidated auto-generated +// address's resources from ndp. If the stack has an NDP dispatcher, it will +// be notified that addr has been invalidated. +// +// Returns true if ndp had resources for addr to cleanup. +// +// The NIC that ndp belongs to MUST be locked. +func (ndp *ndpState) cleanupAutoGenAddrResourcesAndNotify(addr tcpip.Address) bool { + state, ok := ndp.autoGenAddresses[addr] + + if !ok { + return false + } + + if state.invalidationTimer != nil { + state.invalidationTimer.Stop() + state.invalidationTimer = nil + *state.doNotInvalidate = true + } + + state.doNotInvalidate = nil + + delete(ndp.autoGenAddresses, addr) + + if ndp.nic.stack.ndpDisp != nil { + ndp.nic.stack.ndpDisp.OnAutoGenAddressInvalidated(ndp.nic.ID(), tcpip.AddressWithPrefix{ + Address: addr, + PrefixLen: validPrefixLenForAutoGen, + }) + } + + return true +} + +// autoGenAddrInvalidationTimer returns a new invalidation timer for an +// auto-generated address that fires after vl. +// +// doNotInvalidate is used to inform the timer when it fires at the same time +// that an auto-generated address's valid lifetime gets refreshed. See +// autoGenAddrState.doNotInvalidate for more details. +func (ndp *ndpState) autoGenAddrInvalidationTimer(addr tcpip.Address, vl time.Duration, doNotInvalidate *bool) *time.Timer { + return time.AfterFunc(vl, func() { + ndp.nic.mu.Lock() + defer ndp.nic.mu.Unlock() + + if *doNotInvalidate { + *doNotInvalidate = false + return + } + + ndp.invalidateAutoGenAddress(addr) + }) +} diff --git a/pkg/tcpip/stack/ndp_test.go b/pkg/tcpip/stack/ndp_test.go index b2af78212..e9aa20148 100644 --- a/pkg/tcpip/stack/ndp_test.go +++ b/pkg/tcpip/stack/ndp_test.go @@ -38,7 +38,7 @@ const ( linkAddr1 = "\x02\x02\x03\x04\x05\x06" linkAddr2 = "\x02\x02\x03\x04\x05\x07" linkAddr3 = "\x02\x02\x03\x04\x05\x08" - defaultTimeout = 250 * time.Millisecond + defaultTimeout = 100 * time.Millisecond ) var ( @@ -47,6 +47,31 @@ var ( llAddr3 = header.LinkLocalAddr(linkAddr3) ) +// 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. +func prefixSubnetAddr(offset uint8, linkAddr tcpip.LinkAddress) (tcpip.AddressWithPrefix, tcpip.Subnet, tcpip.AddressWithPrefix) { + prefixBytes := []byte{1, 2, 3, 4, 5, 6, 7, 8 + offset, 0, 0, 0, 0, 0, 0, 0, 0} + prefix := tcpip.AddressWithPrefix{ + Address: tcpip.Address(prefixBytes), + PrefixLen: 64, + } + + subnet := prefix.Subnet() + + var addr tcpip.AddressWithPrefix + if header.IsValidUnicastEthernetAddress(linkAddr) { + addrBytes := []byte(subnet.ID()) + header.EthernetAdddressToEUI64IntoBuf(linkAddr, addrBytes[header.IIDOffsetInIPv6Address:]) + addr = tcpip.AddressWithPrefix{ + Address: tcpip.Address(addrBytes), + PrefixLen: 64, + } + } + + return prefix, subnet, addr +} + // TestDADDisabled tests that an address successfully resolves immediately // when DAD is not enabled (the default for an empty stack.Options). func TestDADDisabled(t *testing.T) { @@ -103,6 +128,19 @@ type ndpPrefixEvent struct { discovered bool } +type ndpAutoGenAddrEventType int + +const ( + newAddr ndpAutoGenAddrEventType = iota + invalidatedAddr +) + +type ndpAutoGenAddrEvent struct { + nicID tcpip.NICID + addr tcpip.AddressWithPrefix + eventType ndpAutoGenAddrEventType +} + var _ stack.NDPDispatcher = (*ndpDispatcher)(nil) // ndpDispatcher implements NDPDispatcher so tests can know when various NDP @@ -113,6 +151,7 @@ type ndpDispatcher struct { rememberRouter bool prefixC chan ndpPrefixEvent rememberPrefix bool + autoGenAddrC chan ndpAutoGenAddrEvent routeTable []tcpip.Route } @@ -211,7 +250,7 @@ func (n *ndpDispatcher) OnOnLinkPrefixInvalidated(nicID tcpip.NICID, prefix tcpi } } - rt := make([]tcpip.Route, 0) + var rt []tcpip.Route exclude := tcpip.Route{ Destination: prefix, NIC: nicID, @@ -226,6 +265,27 @@ func (n *ndpDispatcher) OnOnLinkPrefixInvalidated(nicID tcpip.NICID, prefix tcpi return rt } +func (n *ndpDispatcher) OnAutoGenAddress(nicID tcpip.NICID, addr tcpip.AddressWithPrefix) bool { + if n.autoGenAddrC != nil { + n.autoGenAddrC <- ndpAutoGenAddrEvent{ + nicID, + addr, + newAddr, + } + } + return true +} + +func (n *ndpDispatcher) OnAutoGenAddressInvalidated(nicID tcpip.NICID, addr tcpip.AddressWithPrefix) { + if n.autoGenAddrC != nil { + n.autoGenAddrC <- ndpAutoGenAddrEvent{ + nicID, + addr, + invalidatedAddr, + } + } +} + // TestDADResolve tests that an address successfully resolves after performing // DAD for various values of DupAddrDetectTransmits and RetransmitTimer. // Included in the subtests is a test to make sure that an invalid @@ -247,6 +307,8 @@ func TestDADResolve(t *testing.T) { for _, test := range tests { t.Run(test.name, func(t *testing.T) { + t.Parallel() + ndpDisp := ndpDispatcher{ dadC: make(chan ndpDADEvent), } @@ -781,16 +843,33 @@ func raBuf(ip tcpip.Address, rl uint16) tcpip.PacketBuffer { // // Note, raBufWithPI does not populate any of the RA fields other than the // Router Lifetime. -func raBufWithPI(ip tcpip.Address, rl uint16, prefix tcpip.AddressWithPrefix, onLink bool, vl uint32) tcpip.PacketBuffer { +func raBufWithPI(ip tcpip.Address, rl uint16, prefix tcpip.AddressWithPrefix, onLink, auto bool, vl, pl uint32) tcpip.PacketBuffer { flags := uint8(0) if onLink { - flags |= 128 + // The OnLink flag is the 7th bit in the flags byte. + flags |= 1 << 7 + } + if auto { + // The Address Auto-Configuration flag is the 6th bit in the + // flags byte. + flags |= 1 << 6 } + // A valid header.NDPPrefixInformation must be 30 bytes. buf := [30]byte{} + // The first byte in a header.NDPPrefixInformation is the Prefix Length + // field. buf[0] = uint8(prefix.PrefixLen) + // The 2nd byte within a header.NDPPrefixInformation is the Flags field. buf[1] = flags + // The Valid Lifetime field starts after the 2nd byte within a + // header.NDPPrefixInformation. binary.BigEndian.PutUint32(buf[2:], vl) + // The Preferred Lifetime field starts after the 6th byte within a + // header.NDPPrefixInformation. + binary.BigEndian.PutUint32(buf[6:], pl) + // The Prefix Address field starts after the 14th byte within a + // header.NDPPrefixInformation. copy(buf[14:], prefix.Address) return raBufWithOpts(ip, rl, header.NDPOptionsSerializer{ header.NDPPrefixInformation(buf[:]), @@ -800,6 +879,8 @@ func raBufWithPI(ip tcpip.Address, rl uint16, prefix tcpip.AddressWithPrefix, on // TestNoRouterDiscovery tests that router discovery will not be performed if // configured not to. func TestNoRouterDiscovery(t *testing.T) { + t.Parallel() + // Being configured to discover routers means handle and // discover are set to true and forwarding is set to false. // This tests all possible combinations of the configurations, @@ -812,6 +893,8 @@ func TestNoRouterDiscovery(t *testing.T) { forwarding := i&4 == 0 t.Run(fmt.Sprintf("HandleRAs(%t), DiscoverDefaultRouters(%t), Forwarding(%t)", handle, discover, forwarding), func(t *testing.T) { + t.Parallel() + ndpDisp := ndpDispatcher{ routerC: make(chan ndpRouterEvent, 10), } @@ -844,6 +927,8 @@ func TestNoRouterDiscovery(t *testing.T) { // TestRouterDiscoveryDispatcherNoRemember tests that the stack does not // remember a discovered router when the dispatcher asks it not to. func TestRouterDiscoveryDispatcherNoRemember(t *testing.T) { + t.Parallel() + ndpDisp := ndpDispatcher{ routerC: make(chan ndpRouterEvent, 10), } @@ -909,6 +994,8 @@ func TestRouterDiscoveryDispatcherNoRemember(t *testing.T) { } func TestRouterDiscovery(t *testing.T) { + t.Parallel() + ndpDisp := ndpDispatcher{ routerC: make(chan ndpRouterEvent, 10), rememberRouter: true, @@ -1040,6 +1127,8 @@ func TestRouterDiscovery(t *testing.T) { // TestRouterDiscoveryMaxRouters tests that only // stack.MaxDiscoveredDefaultRouters discovered routers are remembered. func TestRouterDiscoveryMaxRouters(t *testing.T) { + t.Parallel() + ndpDisp := ndpDispatcher{ routerC: make(chan ndpRouterEvent, 10), rememberRouter: true, @@ -1104,6 +1193,8 @@ func TestRouterDiscoveryMaxRouters(t *testing.T) { // TestNoPrefixDiscovery tests that prefix discovery will not be performed if // configured not to. func TestNoPrefixDiscovery(t *testing.T) { + t.Parallel() + prefix := tcpip.AddressWithPrefix{ Address: tcpip.Address("\x01\x02\x03\x04\x05\x06\x07\x08\x00\x00\x00\x00\x00\x00\x00\x00"), PrefixLen: 64, @@ -1121,6 +1212,8 @@ func TestNoPrefixDiscovery(t *testing.T) { forwarding := i&4 == 0 t.Run(fmt.Sprintf("HandleRAs(%t), DiscoverOnLinkPrefixes(%t), Forwarding(%t)", handle, discover, forwarding), func(t *testing.T) { + t.Parallel() + ndpDisp := ndpDispatcher{ prefixC: make(chan ndpPrefixEvent, 10), } @@ -1140,7 +1233,7 @@ func TestNoPrefixDiscovery(t *testing.T) { } // Rx an RA with prefix with non-zero lifetime. - e.InjectInbound(header.IPv6ProtocolNumber, raBufWithPI(llAddr2, 0, prefix, true, 10)) + e.InjectInbound(header.IPv6ProtocolNumber, raBufWithPI(llAddr2, 0, prefix, true, false, 10, 0)) select { case <-ndpDisp.prefixC: @@ -1154,11 +1247,9 @@ func TestNoPrefixDiscovery(t *testing.T) { // TestPrefixDiscoveryDispatcherNoRemember tests that the stack does not // remember a discovered on-link prefix when the dispatcher asks it not to. func TestPrefixDiscoveryDispatcherNoRemember(t *testing.T) { - prefix := tcpip.AddressWithPrefix{ - Address: tcpip.Address("\x01\x02\x03\x04\x05\x06\x07\x08\x00\x00\x00\x00\x00\x00\x00\x00"), - PrefixLen: 64, - } - subnet := prefix.Subnet() + t.Parallel() + + prefix, subnet, _ := prefixSubnetAddr(0, "") ndpDisp := ndpDispatcher{ prefixC: make(chan ndpPrefixEvent, 10), @@ -1189,7 +1280,7 @@ func TestPrefixDiscoveryDispatcherNoRemember(t *testing.T) { // Rx an RA with prefix with a short lifetime. const lifetime = 1 - e.InjectInbound(header.IPv6ProtocolNumber, raBufWithPI(llAddr2, 0, prefix, true, lifetime)) + e.InjectInbound(header.IPv6ProtocolNumber, raBufWithPI(llAddr2, 0, prefix, true, false, lifetime, 0)) select { case r := <-ndpDisp.prefixC: if r.nicID != 1 { @@ -1226,21 +1317,11 @@ func TestPrefixDiscoveryDispatcherNoRemember(t *testing.T) { } func TestPrefixDiscovery(t *testing.T) { - prefix1 := tcpip.AddressWithPrefix{ - Address: tcpip.Address("\x01\x02\x03\x04\x05\x06\x07\x08\x00\x00\x00\x00\x00\x00\x00\x00"), - PrefixLen: 64, - } - prefix2 := tcpip.AddressWithPrefix{ - Address: tcpip.Address("\x01\x02\x03\x04\x05\x06\x07\x09\x00\x00\x00\x00\x00\x00\x00\x00"), - PrefixLen: 64, - } - prefix3 := tcpip.AddressWithPrefix{ - Address: tcpip.Address("\x01\x02\x03\x04\x05\x06\x07\x09\x0a\x00\x00\x00\x00\x00\x00\x00"), - PrefixLen: 72, - } - subnet1 := prefix1.Subnet() - subnet2 := prefix2.Subnet() - subnet3 := prefix3.Subnet() + t.Parallel() + + prefix1, subnet1, _ := prefixSubnetAddr(0, "") + prefix2, subnet2, _ := prefixSubnetAddr(1, "") + prefix3, subnet3, _ := prefixSubnetAddr(2, "") ndpDisp := ndpDispatcher{ prefixC: make(chan ndpPrefixEvent, 10), @@ -1281,7 +1362,7 @@ func TestPrefixDiscovery(t *testing.T) { // Receive an RA with prefix1 in an NDP Prefix Information option (PI) // with zero valid lifetime. - e.InjectInbound(header.IPv6ProtocolNumber, raBufWithPI(llAddr2, 0, prefix1, true, 0)) + e.InjectInbound(header.IPv6ProtocolNumber, raBufWithPI(llAddr2, 0, prefix1, true, false, 0, 0)) select { case <-ndpDisp.prefixC: t.Fatal("unexpectedly discovered a prefix with 0 lifetime") @@ -1290,7 +1371,7 @@ func TestPrefixDiscovery(t *testing.T) { // Receive an RA with prefix1 in an NDP Prefix Information option (PI) // with non-zero lifetime. - e.InjectInbound(header.IPv6ProtocolNumber, raBufWithPI(llAddr2, 0, prefix1, true, 100)) + e.InjectInbound(header.IPv6ProtocolNumber, raBufWithPI(llAddr2, 0, prefix1, true, false, 100, 0)) waitForEvent(subnet1, true, defaultTimeout) // Should have added a device route for subnet1 through the nic. @@ -1299,7 +1380,7 @@ func TestPrefixDiscovery(t *testing.T) { } // Receive an RA with prefix2 in a PI. - e.InjectInbound(header.IPv6ProtocolNumber, raBufWithPI(llAddr2, 0, prefix2, true, 100)) + e.InjectInbound(header.IPv6ProtocolNumber, raBufWithPI(llAddr2, 0, prefix2, true, false, 100, 0)) waitForEvent(subnet2, true, defaultTimeout) // Should have added a device route for subnet2 through the nic. @@ -1308,7 +1389,7 @@ func TestPrefixDiscovery(t *testing.T) { } // Receive an RA with prefix3 in a PI. - e.InjectInbound(header.IPv6ProtocolNumber, raBufWithPI(llAddr2, 0, prefix3, true, 100)) + e.InjectInbound(header.IPv6ProtocolNumber, raBufWithPI(llAddr2, 0, prefix3, true, false, 100, 0)) waitForEvent(subnet3, true, defaultTimeout) // Should have added a device route for subnet3 through the nic. @@ -1317,7 +1398,7 @@ func TestPrefixDiscovery(t *testing.T) { } // Receive an RA with prefix1 in a PI with lifetime = 0. - e.InjectInbound(header.IPv6ProtocolNumber, raBufWithPI(llAddr2, 0, prefix1, true, 0)) + e.InjectInbound(header.IPv6ProtocolNumber, raBufWithPI(llAddr2, 0, prefix1, true, false, 0, 0)) waitForEvent(subnet1, false, defaultTimeout) // Should have removed the device route for subnet1 through the nic. @@ -1327,7 +1408,7 @@ func TestPrefixDiscovery(t *testing.T) { // Receive an RA with prefix2 in a PI with lesser lifetime. lifetime := uint32(2) - e.InjectInbound(header.IPv6ProtocolNumber, raBufWithPI(llAddr2, 0, prefix2, true, lifetime)) + e.InjectInbound(header.IPv6ProtocolNumber, raBufWithPI(llAddr2, 0, prefix2, true, false, lifetime, 0)) select { case <-ndpDisp.prefixC: t.Fatal("unexpectedly received prefix event when updating lifetime") @@ -1349,7 +1430,7 @@ func TestPrefixDiscovery(t *testing.T) { } // Receive RA to invalidate prefix3. - e.InjectInbound(header.IPv6ProtocolNumber, raBufWithPI(llAddr2, 0, prefix3, true, 0)) + e.InjectInbound(header.IPv6ProtocolNumber, raBufWithPI(llAddr2, 0, prefix3, true, false, 0, 0)) waitForEvent(subnet3, false, defaultTimeout) // Should not have any routes. @@ -1415,7 +1496,7 @@ func TestPrefixDiscoveryWithInfiniteLifetime(t *testing.T) { // Receive an RA with prefix in an NDP Prefix Information option (PI) // with infinite valid lifetime which should not get invalidated. - e.InjectInbound(header.IPv6ProtocolNumber, raBufWithPI(llAddr2, 0, prefix, true, testInfiniteLifetimeSeconds)) + e.InjectInbound(header.IPv6ProtocolNumber, raBufWithPI(llAddr2, 0, prefix, true, false, testInfiniteLifetimeSeconds, 0)) waitForEvent(true, defaultTimeout) select { case <-ndpDisp.prefixC: @@ -1425,16 +1506,16 @@ func TestPrefixDiscoveryWithInfiniteLifetime(t *testing.T) { // Receive an RA with finite lifetime. // The prefix should get invalidated after 1s. - e.InjectInbound(header.IPv6ProtocolNumber, raBufWithPI(llAddr2, 0, prefix, true, testInfiniteLifetimeSeconds-1)) + e.InjectInbound(header.IPv6ProtocolNumber, raBufWithPI(llAddr2, 0, prefix, true, false, testInfiniteLifetimeSeconds-1, 0)) waitForEvent(false, testInfiniteLifetime) // Receive an RA with finite lifetime. - e.InjectInbound(header.IPv6ProtocolNumber, raBufWithPI(llAddr2, 0, prefix, true, testInfiniteLifetimeSeconds-1)) + e.InjectInbound(header.IPv6ProtocolNumber, raBufWithPI(llAddr2, 0, prefix, true, false, testInfiniteLifetimeSeconds-1, 0)) waitForEvent(true, defaultTimeout) // Receive an RA with prefix with an infinite lifetime. // The prefix should not be invalidated. - e.InjectInbound(header.IPv6ProtocolNumber, raBufWithPI(llAddr2, 0, prefix, true, testInfiniteLifetimeSeconds)) + e.InjectInbound(header.IPv6ProtocolNumber, raBufWithPI(llAddr2, 0, prefix, true, false, testInfiniteLifetimeSeconds, 0)) select { case <-ndpDisp.prefixC: t.Fatal("unexpectedly invalidated a prefix with infinite lifetime") @@ -1443,7 +1524,7 @@ func TestPrefixDiscoveryWithInfiniteLifetime(t *testing.T) { // Receive an RA with a prefix with a lifetime value greater than the // set infinite lifetime value. - e.InjectInbound(header.IPv6ProtocolNumber, raBufWithPI(llAddr2, 0, prefix, true, testInfiniteLifetimeSeconds+1)) + e.InjectInbound(header.IPv6ProtocolNumber, raBufWithPI(llAddr2, 0, prefix, true, false, testInfiniteLifetimeSeconds+1, 0)) select { case <-ndpDisp.prefixC: t.Fatal("unexpectedly invalidated a prefix with infinite lifetime") @@ -1452,13 +1533,15 @@ func TestPrefixDiscoveryWithInfiniteLifetime(t *testing.T) { // Receive an RA with 0 lifetime. // The prefix should get invalidated. - e.InjectInbound(header.IPv6ProtocolNumber, raBufWithPI(llAddr2, 0, prefix, true, 0)) + e.InjectInbound(header.IPv6ProtocolNumber, raBufWithPI(llAddr2, 0, prefix, true, false, 0, 0)) waitForEvent(false, defaultTimeout) } // TestPrefixDiscoveryMaxRouters tests that only // stack.MaxDiscoveredOnLinkPrefixes discovered on-link prefixes are remembered. func TestPrefixDiscoveryMaxOnLinkPrefixes(t *testing.T) { + t.Parallel() + ndpDisp := ndpDispatcher{ prefixC: make(chan ndpPrefixEvent, stack.MaxDiscoveredOnLinkPrefixes+3), rememberPrefix: true, @@ -1537,3 +1620,458 @@ func TestPrefixDiscoveryMaxOnLinkPrefixes(t *testing.T) { t.Fatalf("got GetRouteTable = %v, want = %v", got, expectedRt) } } + +// Checks to see if list contains an IPv6 address, item. +func contains(list []tcpip.ProtocolAddress, item tcpip.AddressWithPrefix) bool { + protocolAddress := tcpip.ProtocolAddress{ + Protocol: header.IPv6ProtocolNumber, + AddressWithPrefix: item, + } + + for _, i := range list { + if i == protocolAddress { + return true + } + } + + return false +} + +// TestNoAutoGenAddr tests that SLAAC is not performed when configured not to. +func TestNoAutoGenAddr(t *testing.T) { + t.Parallel() + + prefix, _, _ := prefixSubnetAddr(0, "") + + // Being configured to auto-generate addresses means handle and + // autogen are set to true and forwarding is set to false. + // This tests all possible combinations of the configurations, + // except for the configuration where handle = true, autogen = + // true and forwarding = false (the required configuration to do + // SLAAC) - that will done in other tests. + for i := 0; i < 7; i++ { + handle := i&1 != 0 + autogen := i&2 != 0 + forwarding := i&4 == 0 + + t.Run(fmt.Sprintf("HandleRAs(%t), AutoGenAddr(%t), Forwarding(%t)", handle, autogen, forwarding), func(t *testing.T) { + t.Parallel() + + ndpDisp := ndpDispatcher{ + autoGenAddrC: make(chan ndpAutoGenAddrEvent, 10), + } + e := channel.New(10, 1280, linkAddr1) + s := stack.New(stack.Options{ + NetworkProtocols: []stack.NetworkProtocol{ipv6.NewProtocol()}, + NDPConfigs: stack.NDPConfigurations{ + HandleRAs: handle, + AutoGenGlobalAddresses: autogen, + }, + NDPDisp: &ndpDisp, + }) + s.SetForwarding(forwarding) + + if err := s.CreateNIC(1, e); err != nil { + t.Fatalf("CreateNIC(1) = %s", err) + } + + // Rx an RA with prefix with non-zero lifetime. + e.InjectInbound(header.IPv6ProtocolNumber, raBufWithPI(llAddr2, 0, prefix, false, true, 10, 0)) + + select { + case <-ndpDisp.autoGenAddrC: + t.Fatal("unexpectedly auto-generated an address when configured not to") + case <-time.After(defaultTimeout): + } + }) + } +} + +// TestAutoGenAddr tests that an address is properly generated and invalidated +// when configured to do so. +func TestAutoGenAddr(t *testing.T) { + const newMinVL = 2 + newMinVLDuration := newMinVL * time.Second + saved := stack.MinPrefixInformationValidLifetimeForUpdate + defer func() { + stack.MinPrefixInformationValidLifetimeForUpdate = saved + }() + stack.MinPrefixInformationValidLifetimeForUpdate = newMinVLDuration + + prefix1, _, addr1 := prefixSubnetAddr(0, linkAddr1) + prefix2, _, addr2 := prefixSubnetAddr(1, linkAddr1) + + ndpDisp := ndpDispatcher{ + autoGenAddrC: make(chan ndpAutoGenAddrEvent, 10), + } + e := channel.New(10, 1280, linkAddr1) + s := stack.New(stack.Options{ + NetworkProtocols: []stack.NetworkProtocol{ipv6.NewProtocol()}, + NDPConfigs: stack.NDPConfigurations{ + HandleRAs: true, + AutoGenGlobalAddresses: true, + }, + NDPDisp: &ndpDisp, + }) + + waitForEvent := func(addr tcpip.AddressWithPrefix, eventType ndpAutoGenAddrEventType, timeout time.Duration) { + t.Helper() + + select { + case r := <-ndpDisp.autoGenAddrC: + if r.nicID != 1 { + t.Fatalf("got r.nicID = %d, want = 1", r.nicID) + } + if r.addr != addr { + t.Fatalf("got r.addr = %s, want = %s", r.addr, addr) + } + if r.eventType != eventType { + t.Fatalf("got r.eventType = %v, want = %v", r.eventType, eventType) + } + case <-time.After(timeout): + t.Fatal("timeout waiting for addr auto gen event") + } + } + + if err := s.CreateNIC(1, e); err != nil { + t.Fatalf("CreateNIC(1) = %s", err) + } + + // Receive an RA with prefix1 in an NDP Prefix Information option (PI) + // with zero valid lifetime. + e.InjectInbound(header.IPv6ProtocolNumber, raBufWithPI(llAddr2, 0, prefix1, true, true, 0, 0)) + select { + case <-ndpDisp.autoGenAddrC: + t.Fatal("unexpectedly auto-generated an address with 0 lifetime") + case <-time.After(defaultTimeout): + } + + // Receive an RA with prefix1 in an NDP Prefix Information option (PI) + // with non-zero lifetime. + e.InjectInbound(header.IPv6ProtocolNumber, raBufWithPI(llAddr2, 0, prefix1, true, true, 100, 0)) + waitForEvent(addr1, newAddr, defaultTimeout) + if !contains(s.NICInfo()[1].ProtocolAddresses, addr1) { + t.Fatalf("Should have %s in the list of addresses", addr1) + } + + // Receive an RA with prefix2 in an NDP Prefix Information option (PI) + // with preferred lifetime > valid lifetime + e.InjectInbound(header.IPv6ProtocolNumber, raBufWithPI(llAddr2, 0, prefix1, true, true, 5, 6)) + select { + case <-ndpDisp.autoGenAddrC: + t.Fatal("unexpectedly auto-generated an address with preferred lifetime > valid lifetime") + case <-time.After(defaultTimeout): + } + + // Receive an RA with prefix2 in a PI. + e.InjectInbound(header.IPv6ProtocolNumber, raBufWithPI(llAddr2, 0, prefix2, true, true, 100, 0)) + waitForEvent(addr2, newAddr, defaultTimeout) + if !contains(s.NICInfo()[1].ProtocolAddresses, addr1) { + t.Fatalf("Should have %s in the list of addresses", addr1) + } + if !contains(s.NICInfo()[1].ProtocolAddresses, addr2) { + t.Fatalf("Should have %s in the list of addresses", addr2) + } + + // Refresh valid lifetime for addr of prefix1. + e.InjectInbound(header.IPv6ProtocolNumber, raBufWithPI(llAddr2, 0, prefix1, true, true, newMinVL, 0)) + select { + case <-ndpDisp.autoGenAddrC: + t.Fatal("unexpectedly auto-generated an address when we already have an address for a prefix") + case <-time.After(defaultTimeout): + } + + // Wait for addr of prefix1 to be invalidated. + waitForEvent(addr1, invalidatedAddr, newMinVLDuration+defaultTimeout) + if contains(s.NICInfo()[1].ProtocolAddresses, addr1) { + t.Fatalf("Should not have %s in the list of addresses", addr1) + } + if !contains(s.NICInfo()[1].ProtocolAddresses, addr2) { + t.Fatalf("Should have %s in the list of addresses", addr2) + } +} + +// TestAutoGenAddrValidLifetimeUpdates tests that the valid lifetime of an +// auto-generated address only gets updated when required to, as specified in +// RFC 4862 section 5.5.3.e. +func TestAutoGenAddrValidLifetimeUpdates(t *testing.T) { + const infiniteVL = 4294967295 + const newMinVL = 5 + saved := stack.MinPrefixInformationValidLifetimeForUpdate + defer func() { + stack.MinPrefixInformationValidLifetimeForUpdate = saved + }() + stack.MinPrefixInformationValidLifetimeForUpdate = newMinVL * time.Second + + prefix, _, addr := prefixSubnetAddr(0, linkAddr1) + + tests := []struct { + name string + ovl uint32 + nvl uint32 + evl uint32 + }{ + // Should update the VL to the minimum VL for updating if the + // new VL is less than newMinVL but was originally greater than + // it. + { + "LargeVLToVLLessThanMinVLForUpdate", + 9999, + 1, + newMinVL, + }, + { + "LargeVLTo0", + 9999, + 0, + newMinVL, + }, + { + "InfiniteVLToVLLessThanMinVLForUpdate", + infiniteVL, + 1, + newMinVL, + }, + { + "InfiniteVLTo0", + infiniteVL, + 0, + newMinVL, + }, + + // Should not update VL if original VL was less than newMinVL + // and the new VL is also less than newMinVL. + { + "ShouldNotUpdateWhenBothOldAndNewAreLessThanMinVLForUpdate", + newMinVL - 1, + newMinVL - 3, + newMinVL - 1, + }, + + // Should take the new VL if the new VL is greater than the + // remaining time or is greater than newMinVL. + { + "MorethanMinVLToLesserButStillMoreThanMinVLForUpdate", + newMinVL + 5, + newMinVL + 3, + newMinVL + 3, + }, + { + "SmallVLToGreaterVLButStillLessThanMinVLForUpdate", + newMinVL - 3, + newMinVL - 1, + newMinVL - 1, + }, + { + "SmallVLToGreaterVLThatIsMoreThaMinVLForUpdate", + newMinVL - 3, + newMinVL + 1, + newMinVL + 1, + }, + } + + const delta = 500 * time.Millisecond + + for _, test := range tests { + t.Run(test.name, func(t *testing.T) { + t.Parallel() + + ndpDisp := ndpDispatcher{ + autoGenAddrC: make(chan ndpAutoGenAddrEvent, 10), + } + e := channel.New(10, 1280, linkAddr1) + s := stack.New(stack.Options{ + NetworkProtocols: []stack.NetworkProtocol{ipv6.NewProtocol()}, + NDPConfigs: stack.NDPConfigurations{ + HandleRAs: true, + AutoGenGlobalAddresses: true, + }, + NDPDisp: &ndpDisp, + }) + + if err := s.CreateNIC(1, e); err != nil { + t.Fatalf("CreateNIC(1) = %s", err) + } + + // Receive an RA with prefix with initial VL, test.ovl. + e.InjectInbound(header.IPv6ProtocolNumber, raBufWithPI(llAddr2, 0, prefix, true, true, test.ovl, 0)) + select { + case r := <-ndpDisp.autoGenAddrC: + if r.nicID != 1 { + t.Fatalf("got r.nicID = %d, want = 1", r.nicID) + } + if r.addr != addr { + t.Fatalf("got r.addr = %s, want = %s", r.addr, addr) + } + if r.eventType != newAddr { + t.Fatalf("got r.eventType = %v, want = %v", r.eventType, newAddr) + } + case <-time.After(defaultTimeout): + t.Fatal("timeout waiting for addr auto gen event") + } + + // Receive an new RA with prefix with new VL, test.nvl. + e.InjectInbound(header.IPv6ProtocolNumber, raBufWithPI(llAddr2, 0, prefix, true, true, test.nvl, 0)) + + // + // Validate that the VL for the address got set to + // test.evl. + // + + // Make sure we do not get any invalidation events + // until atleast 500ms (delta) before test.evl. + select { + case <-ndpDisp.autoGenAddrC: + t.Fatalf("unexpectedly received an auto gen addr event") + case <-time.After(time.Duration(test.evl)*time.Second - delta): + } + + // Wait for another second (2x delta), but now we expect + // the invalidation event. + select { + case r := <-ndpDisp.autoGenAddrC: + if r.nicID != 1 { + t.Fatalf("got r.nicID = %d, want = 1", r.nicID) + } + if r.addr != addr { + t.Fatalf("got r.addr = %s, want = %s", r.addr, addr) + } + if r.eventType != invalidatedAddr { + t.Fatalf("got r.eventType = %v, want = %v", r.eventType, newAddr) + } + case <-time.After(2 * delta): + t.Fatal("timeout waiting for addr auto gen event") + } + }) + } +} + +// TestAutoGenAddrRemoval tests that when auto-generated addresses are removed +// by the user, its resources will be cleaned up and an invalidation event will +// be sent to the integrator. +func TestAutoGenAddrRemoval(t *testing.T) { + t.Parallel() + + prefix, _, addr := prefixSubnetAddr(0, linkAddr1) + + ndpDisp := ndpDispatcher{ + autoGenAddrC: make(chan ndpAutoGenAddrEvent, 10), + } + e := channel.New(10, 1280, linkAddr1) + s := stack.New(stack.Options{ + NetworkProtocols: []stack.NetworkProtocol{ipv6.NewProtocol()}, + NDPConfigs: stack.NDPConfigurations{ + HandleRAs: true, + AutoGenGlobalAddresses: true, + }, + NDPDisp: &ndpDisp, + }) + + if err := s.CreateNIC(1, e); err != nil { + t.Fatalf("CreateNIC(1) = %s", err) + } + + // Receive an RA with prefix with its valid lifetime = lifetime. + const lifetime = 5 + e.InjectInbound(header.IPv6ProtocolNumber, raBufWithPI(llAddr2, 0, prefix, true, true, lifetime, 0)) + select { + case r := <-ndpDisp.autoGenAddrC: + if r.nicID != 1 { + t.Fatalf("got r.nicID = %d, want = 1", r.nicID) + } + if r.addr != addr { + t.Fatalf("got r.addr = %s, want = %s", r.addr, addr) + } + if r.eventType != newAddr { + t.Fatalf("got r.eventType = %v, want = %v", r.eventType, newAddr) + } + case <-time.After(defaultTimeout): + t.Fatal("timeout waiting for addr auto gen event") + } + + // Remove the address. + if err := s.RemoveAddress(1, addr.Address); err != nil { + t.Fatalf("RemoveAddress(_, %s) = %s", addr.Address, err) + } + + // Should get the invalidation event immediately. + select { + case r := <-ndpDisp.autoGenAddrC: + if r.nicID != 1 { + t.Fatalf("got r.nicID = %d, want = 1", r.nicID) + } + if r.addr != addr { + t.Fatalf("got r.addr = %s, want = %s", r.addr, addr) + } + if r.eventType != invalidatedAddr { + t.Fatalf("got r.eventType = %v, want = %v", r.eventType, newAddr) + } + case <-time.After(defaultTimeout): + t.Fatal("timeout waiting for addr auto gen event") + } + + // Wait for the original valid lifetime to make sure the original timer + // got stopped/cleaned up. + select { + case <-ndpDisp.autoGenAddrC: + t.Fatalf("unexpectedly received an auto gen addr event") + case <-time.After(lifetime*time.Second + defaultTimeout): + } +} + +// TestAutoGenAddrStaticConflict tests that if SLAAC generates an address that +// is already assigned to the NIC, the static address remains. +func TestAutoGenAddrStaticConflict(t *testing.T) { + t.Parallel() + + prefix, _, addr := prefixSubnetAddr(0, linkAddr1) + + ndpDisp := ndpDispatcher{ + autoGenAddrC: make(chan ndpAutoGenAddrEvent, 10), + } + e := channel.New(10, 1280, linkAddr1) + s := stack.New(stack.Options{ + NetworkProtocols: []stack.NetworkProtocol{ipv6.NewProtocol()}, + NDPConfigs: stack.NDPConfigurations{ + HandleRAs: true, + AutoGenGlobalAddresses: true, + }, + NDPDisp: &ndpDisp, + }) + + if err := s.CreateNIC(1, e); err != nil { + t.Fatalf("CreateNIC(1) = %s", err) + } + + // Add the address as a static address before SLAAC tries to add it. + if err := s.AddProtocolAddress(1, tcpip.ProtocolAddress{Protocol: header.IPv6ProtocolNumber, AddressWithPrefix: addr}); err != nil { + t.Fatalf("AddAddress(_, %d, %s) = %s", header.IPv6ProtocolNumber, addr.Address, err) + } + if !contains(s.NICInfo()[1].ProtocolAddresses, addr) { + t.Fatalf("Should have %s in the list of addresses", addr1) + } + + // Receive a PI where the generated address will be the same as the one + // that we already have assigned statically. + const lifetime = 5 + e.InjectInbound(header.IPv6ProtocolNumber, raBufWithPI(llAddr2, 0, prefix, true, true, lifetime, 0)) + select { + case <-ndpDisp.autoGenAddrC: + t.Fatal("unexpectedly received an auto gen addr event for an address we already have statically") + case <-time.After(defaultTimeout): + } + if !contains(s.NICInfo()[1].ProtocolAddresses, addr) { + t.Fatalf("Should have %s in the list of addresses", addr1) + } + + // Should not get an invalidation event after the PI's invalidation + // time. + select { + case <-ndpDisp.autoGenAddrC: + t.Fatal("unexpectedly received an auto gen addr event") + case <-time.After(lifetime*time.Second + defaultTimeout): + } + if !contains(s.NICInfo()[1].ProtocolAddresses, addr) { + t.Fatalf("Should have %s in the list of addresses", addr1) + } +} diff --git a/pkg/tcpip/stack/nic.go b/pkg/tcpip/stack/nic.go index 3f8d7312c..e8401c673 100644 --- a/pkg/tcpip/stack/nic.go +++ b/pkg/tcpip/stack/nic.go @@ -115,10 +115,11 @@ func newNIC(stack *Stack, id tcpip.NICID, name string, ep LinkEndpoint, loopback }, }, ndp: ndpState{ - configs: stack.ndpConfigs, - dad: make(map[tcpip.Address]dadState), - defaultRouters: make(map[tcpip.Address]defaultRouterState), - onLinkPrefixes: make(map[tcpip.Subnet]onLinkPrefixState), + configs: stack.ndpConfigs, + dad: make(map[tcpip.Address]dadState), + defaultRouters: make(map[tcpip.Address]defaultRouterState), + onLinkPrefixes: make(map[tcpip.Subnet]onLinkPrefixState), + autoGenAddresses: make(map[tcpip.Address]autoGenAddressState), }, } nic.ndp.nic = nic @@ -244,6 +245,20 @@ func (n *NIC) primaryEndpoint(protocol tcpip.NetworkProtocolNumber) *referencedN return nil } +// hasPermanentAddrLocked returns true if n has a permanent (including currently +// tentative) address, addr. +func (n *NIC) hasPermanentAddrLocked(addr tcpip.Address) bool { + ref, ok := n.endpoints[NetworkEndpointID{addr}] + + if !ok { + return false + } + + kind := ref.getKind() + + return kind == permanent || kind == permanentTentative +} + func (n *NIC) getRef(protocol tcpip.NetworkProtocolNumber, dst tcpip.Address) *referencedNetworkEndpoint { return n.getRefOrCreateTemp(protocol, dst, CanBePrimaryEndpoint, n.promiscuous) } @@ -335,7 +350,7 @@ func (n *NIC) getRefOrCreateTemp(protocol tcpip.NetworkProtocolNumber, address t Address: address, PrefixLen: netProto.DefaultPrefixLen(), }, - }, peb, temporary) + }, peb, temporary, static) n.mu.Unlock() return ref @@ -384,10 +399,10 @@ func (n *NIC) addPermanentAddressLocked(protocolAddress tcpip.ProtocolAddress, p } } - return n.addAddressLocked(protocolAddress, peb, permanent) + return n.addAddressLocked(protocolAddress, peb, permanent, static) } -func (n *NIC) addAddressLocked(protocolAddress tcpip.ProtocolAddress, peb PrimaryEndpointBehavior, kind networkEndpointKind) (*referencedNetworkEndpoint, *tcpip.Error) { +func (n *NIC) addAddressLocked(protocolAddress tcpip.ProtocolAddress, peb PrimaryEndpointBehavior, kind networkEndpointKind, configType networkEndpointConfigType) (*referencedNetworkEndpoint, *tcpip.Error) { // TODO(b/141022673): Validate IP address before adding them. // Sanity check. @@ -417,11 +432,12 @@ func (n *NIC) addAddressLocked(protocolAddress tcpip.ProtocolAddress, peb Primar } ref := &referencedNetworkEndpoint{ - refs: 1, - ep: ep, - nic: n, - protocol: protocolAddress.Protocol, - kind: kind, + refs: 1, + ep: ep, + nic: n, + protocol: protocolAddress.Protocol, + kind: kind, + configType: configType, } // Set up cache if link address resolution exists for this protocol. @@ -624,9 +640,18 @@ func (n *NIC) removePermanentAddressLocked(addr tcpip.Address) *tcpip.Error { isIPv6Unicast := r.protocol == header.IPv6ProtocolNumber && header.IsV6UnicastAddress(addr) - // If we are removing a tentative IPv6 unicast address, stop DAD. - if isIPv6Unicast && kind == permanentTentative { - n.ndp.stopDuplicateAddressDetection(addr) + if isIPv6Unicast { + // If we are removing a tentative IPv6 unicast address, stop + // DAD. + if kind == permanentTentative { + n.ndp.stopDuplicateAddressDetection(addr) + } + + // If we are removing an address generated via SLAAC, cleanup + // its SLAAC resources and notify the integrator. + if r.configType == slaac { + n.ndp.cleanupAutoGenAddrResourcesAndNotify(addr) + } } r.setKind(permanentExpired) @@ -989,7 +1014,7 @@ const ( // removing the permanent address from the NIC. permanent - // An expired permanent endoint is a permanent endoint that had its address + // An expired permanent endpoint is a permanent endpoint that had its address // removed from the NIC, and it is waiting to be removed once no more routes // hold a reference to it. This is achieved by decreasing its reference count // by 1. If its address is re-added before the endpoint is removed, its type @@ -1035,6 +1060,19 @@ func (n *NIC) unregisterPacketEndpoint(netProto tcpip.NetworkProtocolNumber, ep } } +type networkEndpointConfigType int32 + +const ( + // A statically configured endpoint is an address that was added by + // some user-specified action (adding an explicit address, joining a + // multicast group). + static networkEndpointConfigType = iota + + // A slaac configured endpoint is an IPv6 endpoint that was + // added by SLAAC as per RFC 4862 section 5.5.3. + slaac +) + type referencedNetworkEndpoint struct { ep NetworkEndpoint nic *NIC @@ -1050,6 +1088,10 @@ type referencedNetworkEndpoint struct { // networkEndpointKind must only be accessed using {get,set}Kind(). kind networkEndpointKind + + // configType is the method that was used to configure this endpoint. + // This must never change after the endpoint is added to a NIC. + configType networkEndpointConfigType } func (r *referencedNetworkEndpoint) getKind() networkEndpointKind { |