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-rw-r--r--pkg/tcpip/stack/neighbor_cache.go10
-rw-r--r--pkg/tcpip/stack/neighbor_cache_test.go3
-rw-r--r--pkg/tcpip/stack/neighbor_entry.go57
-rw-r--r--pkg/tcpip/stack/neighbor_entry_test.go192
-rw-r--r--pkg/tcpip/stack/neighborstate_string.go7
5 files changed, 195 insertions, 74 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_cache_test.go b/pkg/tcpip/stack/neighbor_cache_test.go
index d60a49fe8..909912662 100644
--- a/pkg/tcpip/stack/neighbor_cache_test.go
+++ b/pkg/tcpip/stack/neighbor_cache_test.go
@@ -1610,12 +1610,11 @@ func TestNeighborCacheRetryResolution(t *testing.T) {
}
}
- // Verify the entry is in Failed state.
wantEntries := []NeighborEntry{
{
Addr: entry.Addr,
LinkAddr: "",
- State: Failed,
+ State: Unreachable,
},
}
if diff := cmp.Diff(linkRes.neigh.entries(), wantEntries, entryDiffOptsWithSort()...); diff != "" {
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/neighbor_entry_test.go b/pkg/tcpip/stack/neighbor_entry_test.go
index f80d4ef8a..47a9e2448 100644
--- a/pkg/tcpip/stack/neighbor_entry_test.go
+++ b/pkg/tcpip/stack/neighbor_entry_test.go
@@ -70,38 +70,39 @@ func eventDiffOptsWithSort() []cmp.Option {
}
// The following unit tests exercise every state transition and verify its
-// behavior with RFC 4681.
+// behavior with RFC 4681 and RFC 7048.
//
-// | From | To | Cause | Update | Action | Event |
-// | ========== | ========== | ========================================== | ======== | ===========| ======= |
-// | Unknown | Unknown | Confirmation w/ unknown address | | | Added |
-// | Unknown | Incomplete | Packet queued to unknown address | | Send probe | Added |
-// | Unknown | Stale | Probe | | | Added |
-// | Incomplete | Incomplete | Retransmit timer expired | | Send probe | Changed |
-// | Incomplete | Reachable | Solicited confirmation | LinkAddr | Notify | Changed |
-// | Incomplete | Stale | Unsolicited confirmation | LinkAddr | Notify | Changed |
-// | Incomplete | Stale | Probe | LinkAddr | Notify | Changed |
-// | Incomplete | Failed | Max probes sent without reply | | Notify | Removed |
-// | Reachable | Reachable | Confirmation w/ different isRouter flag | IsRouter | | |
-// | Reachable | Stale | Reachable timer expired | | | Changed |
-// | Reachable | Stale | Probe or confirmation w/ different address | | | Changed |
-// | Stale | Reachable | Solicited override confirmation | LinkAddr | | Changed |
-// | Stale | Reachable | Solicited confirmation w/o address | | Notify | Changed |
-// | Stale | Stale | Override confirmation | LinkAddr | | Changed |
-// | Stale | Stale | Probe w/ different address | LinkAddr | | Changed |
-// | Stale | Delay | Packet sent | | | Changed |
-// | Delay | Reachable | Upper-layer confirmation | | | Changed |
-// | Delay | Reachable | Solicited override confirmation | LinkAddr | | Changed |
-// | Delay | Reachable | Solicited confirmation w/o address | | Notify | Changed |
-// | Delay | Stale | Probe or confirmation w/ different address | | | Changed |
-// | Delay | Probe | Delay timer expired | | Send probe | Changed |
-// | Probe | Reachable | Solicited override confirmation | LinkAddr | | Changed |
-// | Probe | Reachable | Solicited confirmation w/ same address | | Notify | Changed |
-// | Probe | Reachable | Solicited confirmation w/o address | | Notify | Changed |
-// | Probe | Stale | Probe or confirmation w/ different address | | | Changed |
-// | Probe | Probe | Retransmit timer expired | | | Changed |
-// | Probe | Failed | Max probes sent without reply | | Notify | Removed |
-// | Failed | Incomplete | Packet queued | | Send probe | Added |
+// | From | To | Cause | Update | Action | Event |
+// | =========== | =========== | ========================================== | ======== | ===========| ======= |
+// | Unknown | Unknown | Confirmation w/ unknown address | | | Added |
+// | Unknown | Incomplete | Packet queued to unknown address | | Send probe | Added |
+// | Unknown | Stale | Probe | | | Added |
+// | Incomplete | Incomplete | Retransmit timer expired | | Send probe | Changed |
+// | Incomplete | Reachable | Solicited confirmation | LinkAddr | Notify | Changed |
+// | Incomplete | Stale | Unsolicited confirmation | LinkAddr | Notify | Changed |
+// | Incomplete | Stale | Probe | LinkAddr | Notify | Changed |
+// | Incomplete | Unreachable | Max probes sent without reply | | Notify | Changed |
+// | Reachable | Reachable | Confirmation w/ different isRouter flag | IsRouter | | |
+// | Reachable | Stale | Reachable timer expired | | | Changed |
+// | Reachable | Stale | Probe or confirmation w/ different address | | | Changed |
+// | Stale | Reachable | Solicited override confirmation | LinkAddr | | Changed |
+// | Stale | Reachable | Solicited confirmation w/o address | | Notify | Changed |
+// | Stale | Stale | Override confirmation | LinkAddr | | Changed |
+// | Stale | Stale | Probe w/ different address | LinkAddr | | Changed |
+// | Stale | Delay | Packet sent | | | Changed |
+// | Delay | Reachable | Upper-layer confirmation | | | Changed |
+// | Delay | Reachable | Solicited override confirmation | LinkAddr | | Changed |
+// | Delay | Reachable | Solicited confirmation w/o address | | Notify | Changed |
+// | Delay | Stale | Probe or confirmation w/ different address | | | Changed |
+// | Delay | Probe | Delay timer expired | | Send probe | Changed |
+// | Probe | Reachable | Solicited override confirmation | LinkAddr | | Changed |
+// | Probe | Reachable | Solicited confirmation w/ same address | | Notify | Changed |
+// | Probe | Reachable | Solicited confirmation w/o address | | Notify | Changed |
+// | Probe | Stale | Probe or confirmation w/ different address | | | Changed |
+// | Probe | Probe | Retransmit timer expired | | | Changed |
+// | Probe | Unreachable | Max probes sent without reply | | Notify | Changed |
+// | Unreachable | Incomplete | Packet queued | | Send probe | Changed |
+// | Unreachable | Stale | Probe w/ different address | LinkAddr | | Changed |
type testEntryEventType uint8
@@ -448,7 +449,7 @@ func TestEntryIncompleteToIncompleteDoesNotChangeUpdatedAt(t *testing.T) {
clock.Advance(c.RetransmitTimer)
// UpdatedAt should change after failing address resolution. Timing out after
- // sending the last probe transitions the entry to Failed.
+ // sending the last probe transitions the entry to Unreachable.
{
wantProbes := []entryTestProbeInfo{
{
@@ -478,12 +479,12 @@ func TestEntryIncompleteToIncompleteDoesNotChangeUpdatedAt(t *testing.T) {
},
},
{
- EventType: entryTestRemoved,
+ EventType: entryTestChanged,
NICID: entryTestNICID,
Entry: NeighborEntry{
Addr: entryTestAddr1,
LinkAddr: tcpip.LinkAddress(""),
- State: Incomplete,
+ State: Unreachable,
},
},
}
@@ -755,7 +756,7 @@ func TestEntryIncompleteToStaleWhenProbe(t *testing.T) {
nudDisp.mu.Unlock()
}
-func TestEntryIncompleteToFailed(t *testing.T) {
+func TestEntryIncompleteToUnreachable(t *testing.T) {
c := DefaultNUDConfigurations()
c.MaxMulticastProbes = 3
e, nudDisp, linkRes, clock := entryTestSetup(c)
@@ -807,12 +808,12 @@ func TestEntryIncompleteToFailed(t *testing.T) {
},
},
{
- EventType: entryTestRemoved,
+ EventType: entryTestChanged,
NICID: entryTestNICID,
Entry: NeighborEntry{
Addr: entryTestAddr1,
LinkAddr: tcpip.LinkAddress(""),
- State: Incomplete,
+ State: Unreachable,
},
},
}
@@ -823,8 +824,8 @@ func TestEntryIncompleteToFailed(t *testing.T) {
nudDisp.mu.Unlock()
e.mu.Lock()
- if e.mu.neigh.State != Failed {
- t.Errorf("got e.mu.neigh.State = %q, want = %q", e.mu.neigh.State, Failed)
+ if e.mu.neigh.State != Unreachable {
+ t.Errorf("got e.mu.neigh.State = %q, want = %q", e.mu.neigh.State, Unreachable)
}
e.mu.Unlock()
}
@@ -3294,7 +3295,7 @@ func TestEntryProbeToReachableWhenSolicitedConfirmationWithoutAddress(t *testing
nudDisp.mu.Unlock()
}
-func TestEntryProbeToFailed(t *testing.T) {
+func TestEntryProbeToUnreachable(t *testing.T) {
c := DefaultNUDConfigurations()
c.MaxMulticastProbes = 3
c.MaxUnicastProbes = 3
@@ -3355,11 +3356,11 @@ func TestEntryProbeToFailed(t *testing.T) {
e.mu.Unlock()
}
- // Wait for the last probe to expire, causing a transition to Failed.
+ // Wait for the last probe to expire, causing a transition to Unreachable.
clock.Advance(c.RetransmitTimer)
e.mu.Lock()
- if e.mu.neigh.State != Failed {
- t.Errorf("got e.mu.neigh.State = %q, want = %q", e.mu.neigh.State, Failed)
+ if e.mu.neigh.State != Unreachable {
+ t.Errorf("got e.mu.neigh.State = %q, want = %q", e.mu.neigh.State, Unreachable)
}
e.mu.Unlock()
@@ -3401,12 +3402,12 @@ func TestEntryProbeToFailed(t *testing.T) {
},
},
{
- EventType: entryTestRemoved,
+ EventType: entryTestChanged,
NICID: entryTestNICID,
Entry: NeighborEntry{
Addr: entryTestAddr1,
LinkAddr: entryTestLinkAddr1,
- State: Probe,
+ State: Unreachable,
},
},
}
@@ -3417,7 +3418,7 @@ func TestEntryProbeToFailed(t *testing.T) {
nudDisp.mu.Unlock()
}
-func TestEntryFailedToIncomplete(t *testing.T) {
+func TestEntryUnreachableToIncomplete(t *testing.T) {
c := DefaultNUDConfigurations()
c.MaxMulticastProbes = 3
e, nudDisp, linkRes, clock := entryTestSetup(c)
@@ -3461,8 +3462,8 @@ func TestEntryFailedToIncomplete(t *testing.T) {
}
e.mu.Lock()
- if e.mu.neigh.State != Failed {
- t.Errorf("got e.mu.neigh.State = %q, want = %q", e.mu.neigh.State, Failed)
+ if e.mu.neigh.State != Unreachable {
+ t.Errorf("got e.mu.neigh.State = %q, want = %q", e.mu.neigh.State, Unreachable)
}
e.mu.Unlock()
@@ -3484,7 +3485,16 @@ func TestEntryFailedToIncomplete(t *testing.T) {
},
},
{
- EventType: entryTestRemoved,
+ EventType: entryTestChanged,
+ NICID: entryTestNICID,
+ Entry: NeighborEntry{
+ Addr: entryTestAddr1,
+ LinkAddr: tcpip.LinkAddress(""),
+ State: Unreachable,
+ },
+ },
+ {
+ EventType: entryTestChanged,
NICID: entryTestNICID,
Entry: NeighborEntry{
Addr: entryTestAddr1,
@@ -3492,6 +3502,72 @@ func TestEntryFailedToIncomplete(t *testing.T) {
State: Incomplete,
},
},
+ }
+ nudDisp.mu.Lock()
+ if diff := cmp.Diff(wantEvents, nudDisp.events, eventDiffOpts()...); diff != "" {
+ t.Errorf("nud dispatcher events mismatch (-want, +got):\n%s", diff)
+ }
+ nudDisp.mu.Unlock()
+}
+
+func TestEntryUnreachableToStale(t *testing.T) {
+ wantProbes := []entryTestProbeInfo{
+ // The Incomplete-to-Incomplete state transition is tested here by
+ // verifying that 3 reachability probes were sent.
+ {
+ RemoteAddress: entryTestAddr1,
+ RemoteLinkAddress: tcpip.LinkAddress(""),
+ LocalAddress: entryTestAddr2,
+ },
+ {
+ RemoteAddress: entryTestAddr1,
+ RemoteLinkAddress: tcpip.LinkAddress(""),
+ LocalAddress: entryTestAddr2,
+ },
+ {
+ RemoteAddress: entryTestAddr1,
+ RemoteLinkAddress: tcpip.LinkAddress(""),
+ LocalAddress: entryTestAddr2,
+ },
+ }
+
+ c := DefaultNUDConfigurations()
+ c.MaxMulticastProbes = uint32(len(wantProbes))
+ e, nudDisp, linkRes, clock := entryTestSetup(c)
+
+ // TODO(gvisor.dev/issue/4872): Use helper functions to start entry tests in
+ // their expected state.
+ e.mu.Lock()
+ e.handlePacketQueuedLocked(entryTestAddr2)
+ if e.mu.neigh.State != Incomplete {
+ t.Errorf("got e.mu.neigh.State = %q, want = %q", e.mu.neigh.State, Incomplete)
+ }
+ e.mu.Unlock()
+
+ waitFor := c.RetransmitTimer * time.Duration(c.MaxMulticastProbes)
+ clock.Advance(waitFor)
+
+ linkRes.mu.Lock()
+ diff := cmp.Diff(wantProbes, linkRes.probes)
+ linkRes.mu.Unlock()
+ if diff != "" {
+ t.Fatalf("link address resolver probes mismatch (-want, +got):\n%s", diff)
+ }
+
+ e.mu.Lock()
+ if e.mu.neigh.State != Unreachable {
+ t.Errorf("got e.mu.neigh.State = %q, want = %q", e.mu.neigh.State, Unreachable)
+ }
+ e.mu.Unlock()
+
+ e.mu.Lock()
+ e.handleProbeLocked(entryTestLinkAddr2)
+ if e.mu.neigh.State != Stale {
+ t.Errorf("got e.mu.neigh.State = %q, want = %q", e.mu.neigh.State, Stale)
+ }
+ e.mu.Unlock()
+
+ wantEvents := []testEntryEventInfo{
{
EventType: entryTestAdded,
NICID: entryTestNICID,
@@ -3501,6 +3577,24 @@ func TestEntryFailedToIncomplete(t *testing.T) {
State: Incomplete,
},
},
+ {
+ EventType: entryTestChanged,
+ NICID: entryTestNICID,
+ Entry: NeighborEntry{
+ Addr: entryTestAddr1,
+ LinkAddr: tcpip.LinkAddress(""),
+ State: Unreachable,
+ },
+ },
+ {
+ EventType: entryTestChanged,
+ NICID: entryTestNICID,
+ Entry: NeighborEntry{
+ Addr: entryTestAddr1,
+ LinkAddr: entryTestLinkAddr2,
+ State: Stale,
+ },
+ },
}
nudDisp.mu.Lock()
if diff := cmp.Diff(wantEvents, nudDisp.events, eventDiffOpts()...); diff != "" {
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) {
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-15 17:34:22 +0000