Completes the soft migration to Unreachable state by removing the Failed state
and the the FailedEntryLookups StatCounter.
Fixes#4667
PiperOrigin-RevId: 358226380
... as per RFC 7048. The Failed state is an internal state that is not
specified by any RFC; replacing it with the Unreachable state enables us to
expose this state while keeping our terminology consistent with RFC 4861 and
RFC 7048.
Unreachable state replaces all internal references for Failed state. However
unlike the Failed state, change events are dispatched when moving into
Unreachable state. This gives developers insight into whether a neighbor entry
failed address resolution or whether it was explicitly removed.
The Failed state will be removed entirely once all references to it are
removed. This is done to avoid a Fuchsia roll failure.
Updates #4667
PiperOrigin-RevId: 356554104
This change implements the Neighbor Unreachability Detection (NUD) state
machine, as per RFC 4861 [1]. The state machine operates on a single neighbor
in the local network. This requires the state machine to be implemented on each
entry of the neighbor table.
This change also adds, but does not expose, several APIs. The first API is for
performing basic operations on the neighbor table:
- Create a static entry
- List all entries
- Delete all entries
- Remove an entry by address
The second API is used for changing the NUD protocol constants on a per-NIC
basis to allow Neighbor Discovery to operate over links with widely varying
performance characteristics. See [RFC 4861 Section 10][2] for the list of
constants.
Finally, the last API is for allowing users to subscribe to NUD state changes.
See [RFC 4861 Appendix C][3] for the list of edges.
[1]: https://tools.ietf.org/html/rfc4861
[2]: https://tools.ietf.org/html/rfc4861#section-10
[3]: https://tools.ietf.org/html/rfc4861#appendix-C
Tests:
pkg/tcpip/stack:stack_test
- TestNeighborCacheAddStaticEntryThenOverflow
- TestNeighborCacheClear
- TestNeighborCacheClearThenOverflow
- TestNeighborCacheConcurrent
- TestNeighborCacheDuplicateStaticEntryWithDifferentLinkAddress
- TestNeighborCacheDuplicateStaticEntryWithSameLinkAddress
- TestNeighborCacheEntry
- TestNeighborCacheEntryNoLinkAddress
- TestNeighborCacheGetConfig
- TestNeighborCacheKeepFrequentlyUsed
- TestNeighborCacheNotifiesWaker
- TestNeighborCacheOverflow
- TestNeighborCacheOverwriteWithStaticEntryThenOverflow
- TestNeighborCacheRemoveEntry
- TestNeighborCacheRemoveEntryThenOverflow
- TestNeighborCacheRemoveStaticEntry
- TestNeighborCacheRemoveStaticEntryThenOverflow
- TestNeighborCacheRemoveWaker
- TestNeighborCacheReplace
- TestNeighborCacheResolutionFailed
- TestNeighborCacheResolutionTimeout
- TestNeighborCacheSetConfig
- TestNeighborCacheStaticResolution
- TestEntryAddsAndClearsWakers
- TestEntryDelayToProbe
- TestEntryDelayToReachableWhenSolicitedOverrideConfirmation
- TestEntryDelayToReachableWhenUpperLevelConfirmation
- TestEntryDelayToStaleWhenConfirmationWithDifferentAddress
- TestEntryDelayToStaleWhenProbeWithDifferentAddress
- TestEntryFailedGetsDeleted
- TestEntryIncompleteToFailed
- TestEntryIncompleteToIncompleteDoesNotChangeUpdatedAt
- TestEntryIncompleteToReachable
- TestEntryIncompleteToReachableWithRouterFlag
- TestEntryIncompleteToStale
- TestEntryInitiallyUnknown
- TestEntryProbeToFailed
- TestEntryProbeToReachableWhenSolicitedConfirmationWithSameAddress
- TestEntryProbeToReachableWhenSolicitedOverrideConfirmation
- TestEntryProbeToStaleWhenConfirmationWithDifferentAddress
- TestEntryProbeToStaleWhenProbeWithDifferentAddress
- TestEntryReachableToStaleWhenConfirmationWithDifferentAddress
- TestEntryReachableToStaleWhenConfirmationWithDifferentAddressAndOverride
- TestEntryReachableToStaleWhenProbeWithDifferentAddress
- TestEntryReachableToStaleWhenTimeout
- TestEntryStaleToDelay
- TestEntryStaleToReachableWhenSolicitedOverrideConfirmation
- TestEntryStaleToStaleWhenOverrideConfirmation
- TestEntryStaleToStaleWhenProbeUpdateAddress
- TestEntryStaysDelayWhenOverrideConfirmationWithSameAddress
- TestEntryStaysProbeWhenOverrideConfirmationWithSameAddress
- TestEntryStaysReachableWhenConfirmationWithRouterFlag
- TestEntryStaysReachableWhenProbeWithSameAddress
- TestEntryStaysStaleWhenProbeWithSameAddress
- TestEntryUnknownToIncomplete
- TestEntryUnknownToStale
- TestEntryUnknownToUnknownWhenConfirmationWithUnknownAddress
pkg/tcpip/stack:stack_x_test
- TestDefaultNUDConfigurations
- TestNUDConfigurationFailsForNotSupported
- TestNUDConfigurationsBaseReachableTime
- TestNUDConfigurationsDelayFirstProbeTime
- TestNUDConfigurationsMaxMulticastProbes
- TestNUDConfigurationsMaxRandomFactor
- TestNUDConfigurationsMaxUnicastProbes
- TestNUDConfigurationsMinRandomFactor
- TestNUDConfigurationsRetransmitTimer
- TestNUDConfigurationsUnreachableTime
- TestNUDStateReachableTime
- TestNUDStateRecomputeReachableTime
- TestSetNUDConfigurationFailsForBadNICID
- TestSetNUDConfigurationFailsForNotSupported
[1]: https://tools.ietf.org/html/rfc4861
[2]: https://tools.ietf.org/html/rfc4861#section-10
[3]: https://tools.ietf.org/html/rfc4861#appendix-C
Updates #1889
Updates #1894
Updates #1895
Updates #1947
Updates #1948
Updates #1949
Updates #1950
PiperOrigin-RevId: 324070795
Sam Balana