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authorgVisor bot <gvisor-bot@google.com>2020-04-28 23:07:19 +0000
committergVisor bot <gvisor-bot@google.com>2020-04-28 23:07:19 +0000
commit0293ccf4aa6bd56b22f8d437997fdd267e4d56c5 (patch)
tree51933385bffe05d28c6077bbf32d6ca26515831c /pkg/tcpip/stack/ndp.go
parent21312786e3d288b1934955d1d8d7e56db000c799 (diff)
parent37a59bc76da7e0b20be3cef1fcb1d5cb8fbc839d (diff)
Merge release-20200413.0-15-g37a59bc (automated)
Diffstat (limited to 'pkg/tcpip/stack/ndp.go')
-rwxr-xr-xpkg/tcpip/stack/ndp.go645
1 files changed, 543 insertions, 102 deletions
diff --git a/pkg/tcpip/stack/ndp.go b/pkg/tcpip/stack/ndp.go
index c11d62f97..fbc0e3f55 100755
--- a/pkg/tcpip/stack/ndp.go
+++ b/pkg/tcpip/stack/ndp.go
@@ -119,6 +119,32 @@ const (
// identifier (IID) is 64 bits and an IPv6 address is 128 bits, so
// 128 - 64 = 64.
validPrefixLenForAutoGen = 64
+
+ // defaultAutoGenTempGlobalAddresses is the default configuration for whether
+ // or not to generate temporary SLAAC addresses.
+ defaultAutoGenTempGlobalAddresses = true
+
+ // defaultMaxTempAddrValidLifetime is the default maximum valid lifetime
+ // for temporary SLAAC addresses generated as part of RFC 4941.
+ //
+ // Default = 7 days (from RFC 4941 section 5).
+ defaultMaxTempAddrValidLifetime = 7 * 24 * time.Hour
+
+ // defaultMaxTempAddrPreferredLifetime is the default preferred lifetime
+ // for temporary SLAAC addresses generated as part of RFC 4941.
+ //
+ // Default = 1 day (from RFC 4941 section 5).
+ defaultMaxTempAddrPreferredLifetime = 24 * time.Hour
+
+ // defaultRegenAdvanceDuration is the default duration before the deprecation
+ // of a temporary address when a new address will be generated.
+ //
+ // Default = 5s (from RFC 4941 section 5).
+ defaultRegenAdvanceDuration = 5 * time.Second
+
+ // minRegenAdvanceDuration is the minimum duration before the deprecation
+ // of a temporary address when a new address will be generated.
+ minRegenAdvanceDuration = time.Duration(0)
)
var (
@@ -131,6 +157,37 @@ var (
//
// Min = 2hrs.
MinPrefixInformationValidLifetimeForUpdate = 2 * time.Hour
+
+ // MaxDesyncFactor is the upper bound for the preferred lifetime's desync
+ // factor for temporary SLAAC addresses.
+ //
+ // This is exported as a variable (instead of a constant) so tests
+ // can update it to a smaller value.
+ //
+ // Must be greater than 0.
+ //
+ // Max = 10m (from RFC 4941 section 5).
+ MaxDesyncFactor = 10 * time.Minute
+
+ // MinMaxTempAddrPreferredLifetime is the minimum value allowed for the
+ // maximum preferred lifetime for temporary SLAAC addresses.
+ //
+ // This is exported as a variable (instead of a constant) so tests
+ // can update it to a smaller value.
+ //
+ // This value guarantees that a temporary address will be preferred for at
+ // least 1hr if the SLAAC prefix is valid for at least that time.
+ MinMaxTempAddrPreferredLifetime = defaultRegenAdvanceDuration + MaxDesyncFactor + time.Hour
+
+ // MinMaxTempAddrValidLifetime is the minimum value allowed for the
+ // maximum valid lifetime for temporary SLAAC addresses.
+ //
+ // This is exported as a variable (instead of a constant) so tests
+ // can update it to a smaller value.
+ //
+ // This value guarantees that a temporary address will be valid for at least
+ // 2hrs if the SLAAC prefix is valid for at least that time.
+ MinMaxTempAddrValidLifetime = 2 * time.Hour
)
// DHCPv6ConfigurationFromNDPRA is a configuration available via DHCPv6 that an
@@ -324,35 +381,49 @@ type NDPConfigurations struct {
// alternative addresses (e.g. IIDs based on the modified EUI64 of a NIC's
// MAC address), then no attempt will be made to resolve the conflict.
AutoGenAddressConflictRetries uint8
+
+ // AutoGenTempGlobalAddresses determines whether or not temporary SLAAC
+ // addresses will be generated for a NIC as part of SLAAC privacy extensions,
+ // RFC 4941.
+ //
+ // Ignored if AutoGenGlobalAddresses is false.
+ AutoGenTempGlobalAddresses bool
+
+ // MaxTempAddrValidLifetime is the maximum valid lifetime for temporary
+ // SLAAC addresses.
+ MaxTempAddrValidLifetime time.Duration
+
+ // MaxTempAddrPreferredLifetime is the maximum preferred lifetime for
+ // temporary SLAAC addresses.
+ MaxTempAddrPreferredLifetime time.Duration
+
+ // RegenAdvanceDuration is the duration before the deprecation of a temporary
+ // address when a new address will be generated.
+ RegenAdvanceDuration time.Duration
}
// DefaultNDPConfigurations returns an NDPConfigurations populated with
// default values.
func DefaultNDPConfigurations() NDPConfigurations {
return NDPConfigurations{
- DupAddrDetectTransmits: defaultDupAddrDetectTransmits,
- RetransmitTimer: defaultRetransmitTimer,
- MaxRtrSolicitations: defaultMaxRtrSolicitations,
- RtrSolicitationInterval: defaultRtrSolicitationInterval,
- MaxRtrSolicitationDelay: defaultMaxRtrSolicitationDelay,
- HandleRAs: defaultHandleRAs,
- DiscoverDefaultRouters: defaultDiscoverDefaultRouters,
- DiscoverOnLinkPrefixes: defaultDiscoverOnLinkPrefixes,
- AutoGenGlobalAddresses: defaultAutoGenGlobalAddresses,
+ DupAddrDetectTransmits: defaultDupAddrDetectTransmits,
+ RetransmitTimer: defaultRetransmitTimer,
+ MaxRtrSolicitations: defaultMaxRtrSolicitations,
+ RtrSolicitationInterval: defaultRtrSolicitationInterval,
+ MaxRtrSolicitationDelay: defaultMaxRtrSolicitationDelay,
+ HandleRAs: defaultHandleRAs,
+ DiscoverDefaultRouters: defaultDiscoverDefaultRouters,
+ DiscoverOnLinkPrefixes: defaultDiscoverOnLinkPrefixes,
+ AutoGenGlobalAddresses: defaultAutoGenGlobalAddresses,
+ AutoGenTempGlobalAddresses: defaultAutoGenTempGlobalAddresses,
+ MaxTempAddrValidLifetime: defaultMaxTempAddrValidLifetime,
+ MaxTempAddrPreferredLifetime: defaultMaxTempAddrPreferredLifetime,
+ RegenAdvanceDuration: defaultRegenAdvanceDuration,
}
}
// validate modifies an NDPConfigurations with valid values. If invalid values
// are present in c, the corresponding default values will be used instead.
-//
-// If RetransmitTimer is less than minimumRetransmitTimer, then a value of
-// defaultRetransmitTimer will be used.
-//
-// If RtrSolicitationInterval is less than minimumRtrSolicitationInterval, then
-// a value of defaultRtrSolicitationInterval will be used.
-//
-// If MaxRtrSolicitationDelay is less than minimumMaxRtrSolicitationDelay, then
-// a value of defaultMaxRtrSolicitationDelay will be used.
func (c *NDPConfigurations) validate() {
if c.RetransmitTimer < minimumRetransmitTimer {
c.RetransmitTimer = defaultRetransmitTimer
@@ -365,6 +436,18 @@ func (c *NDPConfigurations) validate() {
if c.MaxRtrSolicitationDelay < minimumMaxRtrSolicitationDelay {
c.MaxRtrSolicitationDelay = defaultMaxRtrSolicitationDelay
}
+
+ if c.MaxTempAddrValidLifetime < MinMaxTempAddrValidLifetime {
+ c.MaxTempAddrValidLifetime = MinMaxTempAddrValidLifetime
+ }
+
+ if c.MaxTempAddrPreferredLifetime < MinMaxTempAddrPreferredLifetime || c.MaxTempAddrPreferredLifetime > c.MaxTempAddrValidLifetime {
+ c.MaxTempAddrPreferredLifetime = MinMaxTempAddrPreferredLifetime
+ }
+
+ if c.RegenAdvanceDuration < minRegenAdvanceDuration {
+ c.RegenAdvanceDuration = minRegenAdvanceDuration
+ }
}
// ndpState is the per-interface NDP state.
@@ -394,6 +477,14 @@ type ndpState struct {
// The last learned DHCPv6 configuration from an NDP RA.
dhcpv6Configuration DHCPv6ConfigurationFromNDPRA
+
+ // temporaryIIDHistory is the history value used to generate a new temporary
+ // IID.
+ temporaryIIDHistory [header.IIDSize]byte
+
+ // temporaryAddressDesyncFactor is the preferred lifetime's desync factor for
+ // temporary SLAAC addresses.
+ temporaryAddressDesyncFactor time.Duration
}
// dadState holds the Duplicate Address Detection timer and channel to signal
@@ -414,7 +505,7 @@ type dadState struct {
type defaultRouterState struct {
// Timer to invalidate the default router.
//
- // May not be nil.
+ // Must not be nil.
invalidationTimer *tcpip.CancellableTimer
}
@@ -424,20 +515,48 @@ type defaultRouterState struct {
type onLinkPrefixState struct {
// Timer to invalidate the on-link prefix.
//
- // May not be nil.
+ // Must not be nil.
+ invalidationTimer *tcpip.CancellableTimer
+}
+
+// tempSLAACAddrState holds state associated with a temporary SLAAC address.
+type tempSLAACAddrState struct {
+ // Timer to deprecate the temporary SLAAC address.
+ //
+ // Must not be nil.
+ deprecationTimer *tcpip.CancellableTimer
+
+ // Timer to invalidate the temporary SLAAC address.
+ //
+ // Must not be nil.
invalidationTimer *tcpip.CancellableTimer
+
+ // Timer to regenerate the temporary SLAAC address.
+ //
+ // Must not be nil.
+ regenTimer *tcpip.CancellableTimer
+
+ createdAt time.Time
+
+ // The address's endpoint.
+ //
+ // Must not be nil.
+ ref *referencedNetworkEndpoint
+
+ // Has a new temporary SLAAC address already been regenerated?
+ regenerated bool
}
// slaacPrefixState holds state associated with a SLAAC prefix.
type slaacPrefixState struct {
// Timer to deprecate the prefix.
//
- // May not be nil.
+ // Must not be nil.
deprecationTimer *tcpip.CancellableTimer
// Timer to invalidate the prefix.
//
- // May not be nil.
+ // Must not be nil.
invalidationTimer *tcpip.CancellableTimer
// Nonzero only when the address is not valid forever.
@@ -446,19 +565,27 @@ type slaacPrefixState struct {
// Nonzero only when the address is not preferred forever.
preferredUntil time.Time
- // The prefix's permanent address endpoint.
+ // The endpoint for the stable address generated for a SLAAC prefix.
//
// May only be nil when a SLAAC address is being (re-)generated. Otherwise,
- // must not be nil as all SLAAC prefixes must have a SLAAC address.
- ref *referencedNetworkEndpoint
+ // must not be nil as all SLAAC prefixes must have a stable address.
+ stableAddrRef *referencedNetworkEndpoint
+
+ // The temporary (short-lived) addresses generated for the SLAAC prefix.
+ tempAddrs map[tcpip.Address]tempSLAACAddrState
- // The number of times a permanent address has been generated for the prefix.
+ // The next two fields are used by both stable and temporary addresses
+ // generated for a SLAAC prefix. This is safe as only 1 address will be
+ // in the generation and DAD process at any time. That is, no two addresses
+ // will be generated at the same time for a given SLAAC prefix.
+
+ // The number of times an address has been generated.
//
// Addresses may be regenerated in reseponse to a DAD conflicts.
generationAttempts uint8
- // The maximum number of times to attempt regeneration of a permanent SLAAC
- // address in response to DAD conflicts.
+ // The maximum number of times to attempt regeneration of a SLAAC address
+ // in response to DAD conflicts.
maxGenerationAttempts uint8
}
@@ -536,10 +663,10 @@ func (ndp *ndpState) startDuplicateAddressDetection(addr tcpip.Address, ref *ref
}
ndp.nic.mu.Lock()
+ defer ndp.nic.mu.Unlock()
if done {
// If we reach this point, it means that DAD was stopped after we released
// the NIC's read lock and before we obtained the write lock.
- ndp.nic.mu.Unlock()
return
}
@@ -551,8 +678,6 @@ func (ndp *ndpState) startDuplicateAddressDetection(addr tcpip.Address, ref *ref
// schedule the next DAD timer.
remaining--
timer.Reset(ndp.nic.stack.ndpConfigs.RetransmitTimer)
-
- ndp.nic.mu.Unlock()
return
}
@@ -560,15 +685,18 @@ func (ndp *ndpState) startDuplicateAddressDetection(addr tcpip.Address, ref *ref
// the last NDP NS. Either way, clean up addr's DAD state and let the
// integrator know DAD has completed.
delete(ndp.dad, addr)
- ndp.nic.mu.Unlock()
-
- if err != nil {
- log.Printf("ndpdad: error occured during DAD iteration for addr (%s) on NIC(%d); err = %s", addr, ndp.nic.ID(), err)
- }
if ndpDisp := ndp.nic.stack.ndpDisp; ndpDisp != nil {
ndpDisp.OnDuplicateAddressDetectionStatus(ndp.nic.ID(), addr, dadDone, err)
}
+
+ // If DAD resolved for a stable SLAAC address, attempt generation of a
+ // temporary SLAAC address.
+ if dadDone && ref.configType == slaac {
+ // Reset the generation attempts counter as we are starting the generation
+ // of a new address for the SLAAC prefix.
+ ndp.regenerateTempSLAACAddr(ref.addrWithPrefix().Subnet(), true /* resetGenAttempts */)
+ }
})
ndp.dad[addr] = dadState{
@@ -953,9 +1081,10 @@ func (ndp *ndpState) handleAutonomousPrefixInformation(pi header.NDPPrefixInform
prefix := pi.Subnet()
// Check if we already maintain SLAAC state for prefix.
- if _, ok := ndp.slaacPrefixes[prefix]; ok {
+ if state, ok := ndp.slaacPrefixes[prefix]; ok {
// As per RFC 4862 section 5.5.3.e, refresh prefix's SLAAC lifetimes.
- ndp.refreshSLAACPrefixLifetimes(prefix, pl, vl)
+ ndp.refreshSLAACPrefixLifetimes(prefix, &state, pl, vl)
+ ndp.slaacPrefixes[prefix] = state
return
}
@@ -996,7 +1125,7 @@ func (ndp *ndpState) doSLAAC(prefix tcpip.Subnet, pl, vl time.Duration) {
panic(fmt.Sprintf("ndp: must have a slaacPrefixes entry for the deprecated SLAAC prefix %s", prefix))
}
- ndp.deprecateSLAACAddress(state.ref)
+ ndp.deprecateSLAACAddress(state.stableAddrRef)
}),
invalidationTimer: tcpip.NewCancellableTimer(&ndp.nic.mu, func() {
state, ok := ndp.slaacPrefixes[prefix]
@@ -1006,6 +1135,7 @@ func (ndp *ndpState) doSLAAC(prefix tcpip.Subnet, pl, vl time.Duration) {
ndp.invalidateSLAACPrefix(prefix, state)
}),
+ tempAddrs: make(map[tcpip.Address]tempSLAACAddrState),
maxGenerationAttempts: ndp.configs.AutoGenAddressConflictRetries + 1,
}
@@ -1035,9 +1165,49 @@ func (ndp *ndpState) doSLAAC(prefix tcpip.Subnet, pl, vl time.Duration) {
state.validUntil = now.Add(vl)
}
+ // If the address is assigned (DAD resolved), generate a temporary address.
+ if state.stableAddrRef.getKind() == permanent {
+ // Reset the generation attempts counter as we are starting the generation
+ // of a new address for the SLAAC prefix.
+ ndp.generateTempSLAACAddr(prefix, &state, true /* resetGenAttempts */)
+ }
+
ndp.slaacPrefixes[prefix] = state
}
+// addSLAACAddr adds a SLAAC address to the NIC.
+//
+// The NIC that ndp belongs to MUST be locked.
+func (ndp *ndpState) addSLAACAddr(addr tcpip.AddressWithPrefix, configType networkEndpointConfigType, deprecated bool) *referencedNetworkEndpoint {
+ // If the nic already has this address, do nothing further.
+ if ndp.nic.hasPermanentAddrLocked(addr.Address) {
+ return nil
+ }
+
+ // Inform the integrator that we have a new SLAAC address.
+ ndpDisp := ndp.nic.stack.ndpDisp
+ if ndpDisp == nil {
+ return nil
+ }
+
+ if !ndpDisp.OnAutoGenAddress(ndp.nic.ID(), addr) {
+ // Informed by the integrator not to add the address.
+ return nil
+ }
+
+ protocolAddr := tcpip.ProtocolAddress{
+ Protocol: header.IPv6ProtocolNumber,
+ AddressWithPrefix: addr,
+ }
+
+ ref, err := ndp.nic.addAddressLocked(protocolAddr, FirstPrimaryEndpoint, permanent, configType, deprecated)
+ if err != nil {
+ panic(fmt.Sprintf("ndp: error when adding SLAAC address %+v: %s", protocolAddr, err))
+ }
+
+ return ref
+}
+
// generateSLAACAddr generates a SLAAC address for prefix.
//
// Returns true if an address was successfully generated.
@@ -1046,7 +1216,7 @@ func (ndp *ndpState) doSLAAC(prefix tcpip.Subnet, pl, vl time.Duration) {
//
// The NIC that ndp belongs to MUST be locked.
func (ndp *ndpState) generateSLAACAddr(prefix tcpip.Subnet, state *slaacPrefixState) bool {
- if r := state.ref; r != nil {
+ if r := state.stableAddrRef; r != nil {
panic(fmt.Sprintf("ndp: SLAAC prefix %s already has a permenant address %s", prefix, r.addrWithPrefix()))
}
@@ -1085,39 +1255,18 @@ func (ndp *ndpState) generateSLAACAddr(prefix tcpip.Subnet, state *slaacPrefixSt
return false
}
- generatedAddr := tcpip.ProtocolAddress{
- Protocol: header.IPv6ProtocolNumber,
- AddressWithPrefix: tcpip.AddressWithPrefix{
- Address: tcpip.Address(addrBytes),
- PrefixLen: validPrefixLenForAutoGen,
- },
- }
-
- // If the nic already has this address, do nothing further.
- if ndp.nic.hasPermanentAddrLocked(generatedAddr.AddressWithPrefix.Address) {
- return false
- }
-
- // Inform the integrator that we have a new SLAAC address.
- ndpDisp := ndp.nic.stack.ndpDisp
- if ndpDisp == nil {
- return false
+ generatedAddr := tcpip.AddressWithPrefix{
+ Address: tcpip.Address(addrBytes),
+ PrefixLen: validPrefixLenForAutoGen,
}
- if !ndpDisp.OnAutoGenAddress(ndp.nic.ID(), generatedAddr.AddressWithPrefix) {
- // Informed by the integrator not to add the address.
- return false
+ if ref := ndp.addSLAACAddr(generatedAddr, slaac, time.Since(state.preferredUntil) >= 0 /* deprecated */); ref != nil {
+ state.stableAddrRef = ref
+ state.generationAttempts++
+ return true
}
- deprecated := time.Since(state.preferredUntil) >= 0
- ref, err := ndp.nic.addAddressLocked(generatedAddr, FirstPrimaryEndpoint, permanent, slaac, deprecated)
- if err != nil {
- panic(fmt.Sprintf("ndp: error when adding address %+v: %s", generatedAddr, err))
- }
-
- state.generationAttempts++
- state.ref = ref
- return true
+ return false
}
// regenerateSLAACAddr regenerates an address for a SLAAC prefix.
@@ -1143,24 +1292,167 @@ func (ndp *ndpState) regenerateSLAACAddr(prefix tcpip.Subnet) {
ndp.invalidateSLAACPrefix(prefix, state)
}
-// refreshSLAACPrefixLifetimes refreshes the lifetimes of a SLAAC prefix.
+// generateTempSLAACAddr generates a new temporary SLAAC address.
//
-// pl is the new preferred lifetime. vl is the new valid lifetime.
+// If resetGenAttempts is true, the prefix's generation counter will be reset.
+//
+// Returns true if a new address was generated.
+func (ndp *ndpState) generateTempSLAACAddr(prefix tcpip.Subnet, prefixState *slaacPrefixState, resetGenAttempts bool) bool {
+ // Are we configured to auto-generate new temporary global addresses for the
+ // prefix?
+ if !ndp.configs.AutoGenTempGlobalAddresses || prefix == header.IPv6LinkLocalPrefix.Subnet() {
+ return false
+ }
+
+ if resetGenAttempts {
+ prefixState.generationAttempts = 0
+ prefixState.maxGenerationAttempts = ndp.configs.AutoGenAddressConflictRetries + 1
+ }
+
+ // If we have already reached the maximum address generation attempts for the
+ // prefix, do not generate another address.
+ if prefixState.generationAttempts == prefixState.maxGenerationAttempts {
+ return false
+ }
+
+ stableAddr := prefixState.stableAddrRef.ep.ID().LocalAddress
+ now := time.Now()
+
+ // As per RFC 4941 section 3.3 step 4, the valid lifetime of a temporary
+ // address is the lower of the valid lifetime of the stable address or the
+ // maximum temporary address valid lifetime.
+ vl := ndp.configs.MaxTempAddrValidLifetime
+ if prefixState.validUntil != (time.Time{}) {
+ if prefixVL := prefixState.validUntil.Sub(now); vl > prefixVL {
+ vl = prefixVL
+ }
+ }
+
+ if vl <= 0 {
+ // Cannot create an address without a valid lifetime.
+ return false
+ }
+
+ // As per RFC 4941 section 3.3 step 4, the preferred lifetime of a temporary
+ // address is the lower of the preferred lifetime of the stable address or the
+ // maximum temporary address preferred lifetime - the temporary address desync
+ // factor.
+ pl := ndp.configs.MaxTempAddrPreferredLifetime - ndp.temporaryAddressDesyncFactor
+ if prefixState.preferredUntil != (time.Time{}) {
+ if prefixPL := prefixState.preferredUntil.Sub(now); pl > prefixPL {
+ // Respect the preferred lifetime of the prefix, as per RFC 4941 section
+ // 3.3 step 4.
+ pl = prefixPL
+ }
+ }
+
+ // As per RFC 4941 section 3.3 step 5, a temporary address is created only if
+ // the calculated preferred lifetime is greater than the advance regeneration
+ // duration. In particular, we MUST NOT create a temporary address with a zero
+ // Preferred Lifetime.
+ if pl <= ndp.configs.RegenAdvanceDuration {
+ return false
+ }
+
+ generatedAddr := header.GenerateTempIPv6SLAACAddr(ndp.temporaryIIDHistory[:], stableAddr)
+
+ // As per RFC RFC 4941 section 3.3 step 5, we MUST NOT create a temporary
+ // address with a zero preferred lifetime. The checks above ensure this
+ // so we know the address is not deprecated.
+ ref := ndp.addSLAACAddr(generatedAddr, slaacTemp, false /* deprecated */)
+ if ref == nil {
+ return false
+ }
+
+ state := tempSLAACAddrState{
+ deprecationTimer: tcpip.NewCancellableTimer(&ndp.nic.mu, func() {
+ prefixState, ok := ndp.slaacPrefixes[prefix]
+ if !ok {
+ panic(fmt.Sprintf("ndp: must have a slaacPrefixes entry for %s to deprecate temporary address %s", prefix, generatedAddr))
+ }
+
+ tempAddrState, ok := prefixState.tempAddrs[generatedAddr.Address]
+ if !ok {
+ panic(fmt.Sprintf("ndp: must have a tempAddr entry to deprecate temporary address %s", generatedAddr))
+ }
+
+ ndp.deprecateSLAACAddress(tempAddrState.ref)
+ }),
+ invalidationTimer: tcpip.NewCancellableTimer(&ndp.nic.mu, func() {
+ prefixState, ok := ndp.slaacPrefixes[prefix]
+ if !ok {
+ panic(fmt.Sprintf("ndp: must have a slaacPrefixes entry for %s to invalidate temporary address %s", prefix, generatedAddr))
+ }
+
+ tempAddrState, ok := prefixState.tempAddrs[generatedAddr.Address]
+ if !ok {
+ panic(fmt.Sprintf("ndp: must have a tempAddr entry to invalidate temporary address %s", generatedAddr))
+ }
+
+ ndp.invalidateTempSLAACAddr(prefixState.tempAddrs, generatedAddr.Address, tempAddrState)
+ }),
+ regenTimer: tcpip.NewCancellableTimer(&ndp.nic.mu, func() {
+ prefixState, ok := ndp.slaacPrefixes[prefix]
+ if !ok {
+ panic(fmt.Sprintf("ndp: must have a slaacPrefixes entry for %s to regenerate temporary address after %s", prefix, generatedAddr))
+ }
+
+ tempAddrState, ok := prefixState.tempAddrs[generatedAddr.Address]
+ if !ok {
+ panic(fmt.Sprintf("ndp: must have a tempAddr entry to regenerate temporary address after %s", generatedAddr))
+ }
+
+ // If an address has already been regenerated for this address, don't
+ // regenerate another address.
+ if tempAddrState.regenerated {
+ return
+ }
+
+ // Reset the generation attempts counter as we are starting the generation
+ // of a new address for the SLAAC prefix.
+ tempAddrState.regenerated = ndp.generateTempSLAACAddr(prefix, &prefixState, true /* resetGenAttempts */)
+ prefixState.tempAddrs[generatedAddr.Address] = tempAddrState
+ ndp.slaacPrefixes[prefix] = prefixState
+ }),
+ createdAt: now,
+ ref: ref,
+ }
+
+ state.deprecationTimer.Reset(pl)
+ state.invalidationTimer.Reset(vl)
+ state.regenTimer.Reset(pl - ndp.configs.RegenAdvanceDuration)
+
+ prefixState.generationAttempts++
+ prefixState.tempAddrs[generatedAddr.Address] = state
+
+ return true
+}
+
+// regenerateTempSLAACAddr regenerates a temporary address for a SLAAC prefix.
//
// The NIC that ndp belongs to MUST be locked.
-func (ndp *ndpState) refreshSLAACPrefixLifetimes(prefix tcpip.Subnet, pl, vl time.Duration) {
- prefixState, ok := ndp.slaacPrefixes[prefix]
+func (ndp *ndpState) regenerateTempSLAACAddr(prefix tcpip.Subnet, resetGenAttempts bool) {
+ state, ok := ndp.slaacPrefixes[prefix]
if !ok {
- panic(fmt.Sprintf("ndp: SLAAC prefix state not found to refresh lifetimes for %s", prefix))
+ panic(fmt.Sprintf("ndp: SLAAC prefix state not found to regenerate temporary address for %s", prefix))
}
- defer func() { ndp.slaacPrefixes[prefix] = prefixState }()
+ ndp.generateTempSLAACAddr(prefix, &state, resetGenAttempts)
+ ndp.slaacPrefixes[prefix] = state
+}
+
+// refreshSLAACPrefixLifetimes refreshes the lifetimes of a SLAAC prefix.
+//
+// pl is the new preferred lifetime. vl is the new valid lifetime.
+//
+// The NIC that ndp belongs to MUST be locked.
+func (ndp *ndpState) refreshSLAACPrefixLifetimes(prefix tcpip.Subnet, prefixState *slaacPrefixState, pl, vl time.Duration) {
// If the preferred lifetime is zero, then the prefix should be deprecated.
deprecated := pl == 0
if deprecated {
- ndp.deprecateSLAACAddress(prefixState.ref)
+ ndp.deprecateSLAACAddress(prefixState.stableAddrRef)
} else {
- prefixState.ref.deprecated = false
+ prefixState.stableAddrRef.deprecated = false
}
// If prefix was preferred for some finite lifetime before, stop the
@@ -1190,36 +1482,118 @@ func (ndp *ndpState) refreshSLAACPrefixLifetimes(prefix tcpip.Subnet, pl, vl tim
//
// 3) Otherwise, reset the valid lifetime of the prefix to 2 hours.
- // Handle the infinite valid lifetime separately as we do not keep a timer in
- // this case.
if vl >= header.NDPInfiniteLifetime {
+ // Handle the infinite valid lifetime separately as we do not keep a timer
+ // in this case.
prefixState.invalidationTimer.StopLocked()
prefixState.validUntil = time.Time{}
- return
- }
+ } else {
+ var effectiveVl time.Duration
+ var rl time.Duration
+
+ // If the prefix was originally set to be valid forever, assume the
+ // remaining time to be the maximum possible value.
+ if prefixState.validUntil == (time.Time{}) {
+ rl = header.NDPInfiniteLifetime
+ } else {
+ rl = time.Until(prefixState.validUntil)
+ }
- var effectiveVl time.Duration
- var rl time.Duration
+ if vl > MinPrefixInformationValidLifetimeForUpdate || vl > rl {
+ effectiveVl = vl
+ } else if rl > MinPrefixInformationValidLifetimeForUpdate {
+ effectiveVl = MinPrefixInformationValidLifetimeForUpdate
+ }
- // If the prefix was originally set to be valid forever, assume the remaining
- // time to be the maximum possible value.
- if prefixState.validUntil == (time.Time{}) {
- rl = header.NDPInfiniteLifetime
- } else {
- rl = time.Until(prefixState.validUntil)
+ if effectiveVl != 0 {
+ prefixState.invalidationTimer.StopLocked()
+ prefixState.invalidationTimer.Reset(effectiveVl)
+ prefixState.validUntil = now.Add(effectiveVl)
+ }
}
- if vl > MinPrefixInformationValidLifetimeForUpdate || vl > rl {
- effectiveVl = vl
- } else if rl <= MinPrefixInformationValidLifetimeForUpdate {
+ // If DAD is not yet complete on the stable address, there is no need to do
+ // work with temporary addresses.
+ if prefixState.stableAddrRef.getKind() != permanent {
return
- } else {
- effectiveVl = MinPrefixInformationValidLifetimeForUpdate
}
- prefixState.invalidationTimer.StopLocked()
- prefixState.invalidationTimer.Reset(effectiveVl)
- prefixState.validUntil = now.Add(effectiveVl)
+ // Note, we do not need to update the entries in the temporary address map
+ // after updating the timers because the timers are held as pointers.
+ var regenForAddr tcpip.Address
+ allAddressesRegenerated := true
+ for tempAddr, tempAddrState := range prefixState.tempAddrs {
+ // As per RFC 4941 section 3.3 step 4, the valid lifetime of a temporary
+ // address is the lower of the valid lifetime of the stable address or the
+ // maximum temporary address valid lifetime. Note, the valid lifetime of a
+ // temporary address is relative to the address's creation time.
+ validUntil := tempAddrState.createdAt.Add(ndp.configs.MaxTempAddrValidLifetime)
+ if prefixState.validUntil != (time.Time{}) && validUntil.Sub(prefixState.validUntil) > 0 {
+ validUntil = prefixState.validUntil
+ }
+
+ // If the address is no longer valid, invalidate it immediately. Otherwise,
+ // reset the invalidation timer.
+ newValidLifetime := validUntil.Sub(now)
+ if newValidLifetime <= 0 {
+ ndp.invalidateTempSLAACAddr(prefixState.tempAddrs, tempAddr, tempAddrState)
+ continue
+ }
+ tempAddrState.invalidationTimer.StopLocked()
+ tempAddrState.invalidationTimer.Reset(newValidLifetime)
+
+ // As per RFC 4941 section 3.3 step 4, the preferred lifetime of a temporary
+ // address is the lower of the preferred lifetime of the stable address or
+ // the maximum temporary address preferred lifetime - the temporary address
+ // desync factor. Note, the preferred lifetime of a temporary address is
+ // relative to the address's creation time.
+ preferredUntil := tempAddrState.createdAt.Add(ndp.configs.MaxTempAddrPreferredLifetime - ndp.temporaryAddressDesyncFactor)
+ if prefixState.preferredUntil != (time.Time{}) && preferredUntil.Sub(prefixState.preferredUntil) > 0 {
+ preferredUntil = prefixState.preferredUntil
+ }
+
+ // If the address is no longer preferred, deprecate it immediately.
+ // Otherwise, reset the deprecation timer.
+ newPreferredLifetime := preferredUntil.Sub(now)
+ tempAddrState.deprecationTimer.StopLocked()
+ if newPreferredLifetime <= 0 {
+ ndp.deprecateSLAACAddress(tempAddrState.ref)
+ } else {
+ tempAddrState.ref.deprecated = false
+ tempAddrState.deprecationTimer.Reset(newPreferredLifetime)
+ }
+
+ tempAddrState.regenTimer.StopLocked()
+ if tempAddrState.regenerated {
+ } else {
+ allAddressesRegenerated = false
+
+ if newPreferredLifetime <= ndp.configs.RegenAdvanceDuration {
+ // The new preferred lifetime is less than the advance regeneration
+ // duration so regenerate an address for this temporary address
+ // immediately after we finish iterating over the temporary addresses.
+ regenForAddr = tempAddr
+ } else {
+ tempAddrState.regenTimer.Reset(newPreferredLifetime - ndp.configs.RegenAdvanceDuration)
+ }
+ }
+ }
+
+ // Generate a new temporary address if all of the existing temporary addresses
+ // have been regenerated, or we need to immediately regenerate an address
+ // due to an update in preferred lifetime.
+ //
+ // If each temporay address has already been regenerated, no new temporary
+ // address will be generated. To ensure continuation of temporary SLAAC
+ // addresses, we manually try to regenerate an address here.
+ if len(regenForAddr) != 0 || allAddressesRegenerated {
+ // Reset the generation attempts counter as we are starting the generation
+ // of a new address for the SLAAC prefix.
+ if state, ok := prefixState.tempAddrs[regenForAddr]; ndp.generateTempSLAACAddr(prefix, prefixState, true /* resetGenAttempts */) && ok {
+ state.regenerated = true
+ prefixState.tempAddrs[regenForAddr] = state
+ }
+ }
}
// deprecateSLAACAddress marks ref as deprecated and notifies the stack's NDP
@@ -1243,11 +1617,11 @@ func (ndp *ndpState) deprecateSLAACAddress(ref *referencedNetworkEndpoint) {
//
// The NIC that ndp belongs to MUST be locked.
func (ndp *ndpState) invalidateSLAACPrefix(prefix tcpip.Subnet, state slaacPrefixState) {
- if r := state.ref; r != nil {
+ if r := state.stableAddrRef; r != nil {
// Since we are already invalidating the prefix, do not invalidate the
// prefix when removing the address.
- if err := ndp.nic.removePermanentIPv6EndpointLocked(r, false /* allowSLAACPrefixInvalidation */); err != nil {
- panic(fmt.Sprintf("ndp: removePermanentIPv6EndpointLocked(%s, false): %s", r.addrWithPrefix(), err))
+ if err := ndp.nic.removePermanentIPv6EndpointLocked(r, false /* allowSLAACInvalidation */); err != nil {
+ panic(fmt.Sprintf("ndp: error removing stable SLAAC address %s: %s", r.addrWithPrefix(), err))
}
}
@@ -1265,14 +1639,14 @@ func (ndp *ndpState) cleanupSLAACAddrResourcesAndNotify(addr tcpip.AddressWithPr
prefix := addr.Subnet()
state, ok := ndp.slaacPrefixes[prefix]
- if !ok || state.ref == nil || addr.Address != state.ref.ep.ID().LocalAddress {
+ if !ok || state.stableAddrRef == nil || addr.Address != state.stableAddrRef.ep.ID().LocalAddress {
return
}
if !invalidatePrefix {
// If the prefix is not being invalidated, disassociate the address from the
// prefix and do nothing further.
- state.ref = nil
+ state.stableAddrRef = nil
ndp.slaacPrefixes[prefix] = state
return
}
@@ -1286,11 +1660,68 @@ func (ndp *ndpState) cleanupSLAACAddrResourcesAndNotify(addr tcpip.AddressWithPr
//
// The NIC that ndp belongs to MUST be locked.
func (ndp *ndpState) cleanupSLAACPrefixResources(prefix tcpip.Subnet, state slaacPrefixState) {
+ // Invalidate all temporary addresses.
+ for tempAddr, tempAddrState := range state.tempAddrs {
+ ndp.invalidateTempSLAACAddr(state.tempAddrs, tempAddr, tempAddrState)
+ }
+
+ state.stableAddrRef = nil
state.deprecationTimer.StopLocked()
state.invalidationTimer.StopLocked()
delete(ndp.slaacPrefixes, prefix)
}
+// invalidateTempSLAACAddr invalidates a temporary SLAAC address.
+//
+// The NIC that ndp belongs to MUST be locked.
+func (ndp *ndpState) invalidateTempSLAACAddr(tempAddrs map[tcpip.Address]tempSLAACAddrState, tempAddr tcpip.Address, tempAddrState tempSLAACAddrState) {
+ // Since we are already invalidating the address, do not invalidate the
+ // address when removing the address.
+ if err := ndp.nic.removePermanentIPv6EndpointLocked(tempAddrState.ref, false /* allowSLAACInvalidation */); err != nil {
+ panic(fmt.Sprintf("error removing temporary SLAAC address %s: %s", tempAddrState.ref.addrWithPrefix(), err))
+ }
+
+ ndp.cleanupTempSLAACAddrResources(tempAddrs, tempAddr, tempAddrState)
+}
+
+// cleanupTempSLAACAddrResourcesAndNotify cleans up an invalidated temporary
+// SLAAC address's resources from ndp.
+//
+// The NIC that ndp belongs to MUST be locked.
+func (ndp *ndpState) cleanupTempSLAACAddrResourcesAndNotify(addr tcpip.AddressWithPrefix, invalidateAddr bool) {
+ if ndpDisp := ndp.nic.stack.ndpDisp; ndpDisp != nil {
+ ndpDisp.OnAutoGenAddressInvalidated(ndp.nic.ID(), addr)
+ }
+
+ if !invalidateAddr {
+ return
+ }
+
+ prefix := addr.Subnet()
+ state, ok := ndp.slaacPrefixes[prefix]
+ if !ok {
+ panic(fmt.Sprintf("ndp: must have a slaacPrefixes entry to clean up temp addr %s resources", addr))
+ }
+
+ tempAddrState, ok := state.tempAddrs[addr.Address]
+ if !ok {
+ panic(fmt.Sprintf("ndp: must have a tempAddr entry to clean up temp addr %s resources", addr))
+ }
+
+ ndp.cleanupTempSLAACAddrResources(state.tempAddrs, addr.Address, tempAddrState)
+}
+
+// cleanupTempSLAACAddrResourcesAndNotify cleans up a temporary SLAAC address's
+// timers and entry.
+//
+// The NIC that ndp belongs to MUST be locked.
+func (ndp *ndpState) cleanupTempSLAACAddrResources(tempAddrs map[tcpip.Address]tempSLAACAddrState, tempAddr tcpip.Address, tempAddrState tempSLAACAddrState) {
+ tempAddrState.deprecationTimer.StopLocked()
+ tempAddrState.invalidationTimer.StopLocked()
+ tempAddrState.regenTimer.StopLocked()
+ delete(tempAddrs, tempAddr)
+}
+
// cleanupState cleans up ndp's state.
//
// If hostOnly is true, then only host-specific state will be cleaned up.
@@ -1450,3 +1881,13 @@ func (ndp *ndpState) stopSolicitingRouters() {
ndp.rtrSolicitTimer.Stop()
ndp.rtrSolicitTimer = nil
}
+
+// initializeTempAddrState initializes state related to temporary SLAAC
+// addresses.
+func (ndp *ndpState) initializeTempAddrState() {
+ header.InitialTempIID(ndp.temporaryIIDHistory[:], ndp.nic.stack.tempIIDSeed, ndp.nic.ID())
+
+ if MaxDesyncFactor != 0 {
+ ndp.temporaryAddressDesyncFactor = time.Duration(rand.Int63n(int64(MaxDesyncFactor)))
+ }
+}