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authorgVisor bot <gvisor-bot@google.com>2021-02-09 19:52:01 +0000
committergVisor bot <gvisor-bot@google.com>2021-02-09 19:52:01 +0000
commit7976b340af1a8a9ad4a806c9284f09407c108684 (patch)
treec69c23fc5384147c0718fd780c1deb7a157ce155
parentfaa5b3394e01ab3639c8e91665557993a90c4016 (diff)
parentd0c0549e607699e0186065ad9186431f12260487 (diff)
Merge release-20210201.0-66-gd0c0549e6 (automated)
-rw-r--r--pkg/tcpip/stack/neighbor_cache.go10
-rw-r--r--pkg/tcpip/stack/neighbor_entry.go57
-rw-r--r--pkg/tcpip/stack/neighborstate_string.go7
3 files changed, 51 insertions, 23 deletions
diff --git a/pkg/tcpip/stack/neighbor_cache.go b/pkg/tcpip/stack/neighbor_cache.go
index a77fe575a..533287c4c 100644
--- a/pkg/tcpip/stack/neighbor_cache.go
+++ b/pkg/tcpip/stack/neighbor_cache.go
@@ -25,9 +25,13 @@ const neighborCacheSize = 512 // max entries per interface
// NeighborStats holds metrics for the neighbor table.
type NeighborStats struct {
- // FailedEntryLookups counts the number of lookups performed on an entry in
- // Failed state.
+ // FailedEntryLookups is deprecated; UnreachableEntryLookups should be used
+ // instead.
FailedEntryLookups *tcpip.StatCounter
+
+ // UnreachableEntryLookups counts the number of lookups performed on an
+ // entry in Unreachable state.
+ UnreachableEntryLookups *tcpip.StatCounter
}
// neighborCache maps IP addresses to link addresses. It uses the Least
@@ -143,7 +147,7 @@ func (n *neighborCache) entry(remoteAddr, localAddr tcpip.Address, onResolve fun
onResolve(LinkResolutionResult{LinkAddress: entry.mu.neigh.LinkAddr, Success: true})
}
return entry.mu.neigh, nil, nil
- case Unknown, Incomplete, Failed:
+ case Unknown, Incomplete, Unreachable:
if onResolve != nil {
entry.mu.onResolve = append(entry.mu.onResolve, onResolve)
}
diff --git a/pkg/tcpip/stack/neighbor_entry.go b/pkg/tcpip/stack/neighbor_entry.go
index 4ed149ee8..03fef52ee 100644
--- a/pkg/tcpip/stack/neighbor_entry.go
+++ b/pkg/tcpip/stack/neighbor_entry.go
@@ -38,7 +38,8 @@ type NeighborEntry struct {
}
// NeighborState defines the state of a NeighborEntry within the Neighbor
-// Unreachability Detection state machine, as per RFC 4861 section 7.3.2.
+// Unreachability Detection state machine, as per RFC 4861 section 7.3.2 and
+// RFC 7048.
type NeighborState uint8
const (
@@ -61,13 +62,24 @@ const (
Delay
// Probe means a reachability confirmation is actively being sought by
// periodically retransmitting reachability probes until a reachability
- // confirmation is received, or until the max amount of probes has been sent.
+ // confirmation is received, or until the maximum number of probes has been
+ // sent.
Probe
// Static describes entries that have been explicitly added by the user. They
// do not expire and are not deleted until explicitly removed.
Static
- // Failed means recent attempts of reachability have returned inconclusive.
+ // Failed is deprecated and should no longer be used.
+ //
+ // TODO(gvisor.dev/issue/4667): Remove this once all references to Failed
+ // are removed from Fuchsia.
Failed
+ // Unreachable means reachability confirmation failed; the maximum number of
+ // reachability probes has been sent and no replies have been received.
+ //
+ // TODO(gvisor.dev/issue/5472): Add the following sentence when we implement
+ // RFC 7048: "Packets continue to be sent to the neighbor while
+ // re-attempting to resolve the address."
+ Unreachable
)
type timer struct {
@@ -310,8 +322,8 @@ func (e *neighborEntry) setStateLocked(next NeighborState) {
}
if timedoutResolution || err != nil {
- e.dispatchRemoveEventLocked()
- e.setStateLocked(Failed)
+ e.setStateLocked(Unreachable)
+ e.dispatchChangeEventLocked()
return
}
@@ -320,7 +332,7 @@ func (e *neighborEntry) setStateLocked(next NeighborState) {
}),
}
- case Failed:
+ case Unreachable:
e.notifyCompletionLocked(false /* succeeded */)
case Unknown, Stale, Static:
@@ -339,15 +351,19 @@ func (e *neighborEntry) setStateLocked(next NeighborState) {
// Precondition: e.mu MUST be locked.
func (e *neighborEntry) handlePacketQueuedLocked(localAddr tcpip.Address) {
switch e.mu.neigh.State {
- case Failed:
- e.cache.nic.stats.Neighbor.FailedEntryLookups.Increment()
-
- fallthrough
- case Unknown:
+ case Unknown, Unreachable:
+ prev := e.mu.neigh.State
e.mu.neigh.State = Incomplete
e.mu.neigh.UpdatedAtNanos = e.cache.nic.stack.clock.NowNanoseconds()
- e.dispatchAddEventLocked()
+ switch prev {
+ case Unknown:
+ e.dispatchAddEventLocked()
+ case Unreachable:
+ e.dispatchChangeEventLocked()
+ e.cache.nic.stats.Neighbor.UnreachableEntryLookups.Increment()
+ }
+
config := e.nudState.Config()
// Protected by e.mu.
@@ -385,8 +401,8 @@ func (e *neighborEntry) handlePacketQueuedLocked(localAddr tcpip.Address) {
}
if timedoutResolution || err != nil {
- e.dispatchRemoveEventLocked()
- e.setStateLocked(Failed)
+ e.setStateLocked(Unreachable)
+ e.dispatchChangeEventLocked()
return
}
@@ -418,7 +434,7 @@ func (e *neighborEntry) handleProbeLocked(remoteLinkAddr tcpip.LinkAddress) {
// checks MUST be done by the NetworkEndpoint.
switch e.mu.neigh.State {
- case Unknown, Failed:
+ case Unknown:
e.mu.neigh.LinkAddr = remoteLinkAddr
e.setStateLocked(Stale)
e.dispatchAddEventLocked()
@@ -447,6 +463,13 @@ func (e *neighborEntry) handleProbeLocked(remoteLinkAddr tcpip.LinkAddress) {
e.dispatchChangeEventLocked()
}
+ case Unreachable:
+ // TODO(gvisor.dev/issue/5472): Do not change the entry if the link
+ // address is the same, as per RFC 7048.
+ e.mu.neigh.LinkAddr = remoteLinkAddr
+ e.setStateLocked(Stale)
+ e.dispatchChangeEventLocked()
+
case Static:
// Do nothing
@@ -549,7 +572,7 @@ func (e *neighborEntry) handleConfirmationLocked(linkAddr tcpip.LinkAddress, fla
}
e.mu.isRouter = flags.IsRouter
- case Unknown, Failed, Static:
+ case Unknown, Unreachable, Static:
// Do nothing
default:
@@ -571,7 +594,7 @@ func (e *neighborEntry) handleUpperLevelConfirmationLocked() {
e.dispatchChangeEventLocked()
}
- case Unknown, Incomplete, Failed, Static:
+ case Unknown, Incomplete, Unreachable, Static:
// Do nothing
default:
diff --git a/pkg/tcpip/stack/neighborstate_string.go b/pkg/tcpip/stack/neighborstate_string.go
index aa7311ec6..765df4d7a 100644
--- a/pkg/tcpip/stack/neighborstate_string.go
+++ b/pkg/tcpip/stack/neighborstate_string.go
@@ -1,4 +1,4 @@
-// Copyright 2020 The gVisor Authors.
+// Copyright 2021 The gVisor Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
@@ -30,11 +30,12 @@ func _() {
_ = x[Probe-5]
_ = x[Static-6]
_ = x[Failed-7]
+ _ = x[Unreachable-8]
}
-const _NeighborState_name = "UnknownIncompleteReachableStaleDelayProbeStaticFailed"
+const _NeighborState_name = "UnknownIncompleteReachableStaleDelayProbeStaticFailedUnreachable"
-var _NeighborState_index = [...]uint8{0, 7, 17, 26, 31, 36, 41, 47, 53}
+var _NeighborState_index = [...]uint8{0, 7, 17, 26, 31, 36, 41, 47, 53, 64}
func (i NeighborState) String() string {
if i >= NeighborState(len(_NeighborState_index)-1) {