diff options
| -rw-r--r-- | pkg/tcpip/stack/neighbor_cache.go | 15 | ||||
| -rw-r--r-- | pkg/tcpip/stack/neighbor_cache_test.go | 66 |
2 files changed, 47 insertions, 34 deletions
diff --git a/pkg/tcpip/stack/neighbor_cache.go b/pkg/tcpip/stack/neighbor_cache.go index 27e1feec0..4df288798 100644 --- a/pkg/tcpip/stack/neighbor_cache.go +++ b/pkg/tcpip/stack/neighbor_cache.go @@ -131,10 +131,17 @@ func (n *neighborCache) entry(remoteAddr, localAddr tcpip.Address, linkRes LinkA defer entry.mu.Unlock() switch s := entry.neigh.State; s { - case Reachable, Static: + case Stale: + entry.handlePacketQueuedLocked() + fallthrough + case Reachable, Static, Delay, Probe: + // As per RFC 4861 section 7.3.3: + // "Neighbor Unreachability Detection operates in parallel with the sending + // of packets to a neighbor. While reasserting a neighbor's reachability, + // a node continues sending packets to that neighbor using the cached + // link-layer address." return entry.neigh, nil, nil - - case Unknown, Incomplete, Stale, Delay, Probe: + case Unknown, Incomplete: entry.addWakerLocked(w) if entry.done == nil { @@ -147,10 +154,8 @@ func (n *neighborCache) entry(remoteAddr, localAddr tcpip.Address, linkRes LinkA entry.handlePacketQueuedLocked() return entry.neigh, entry.done, tcpip.ErrWouldBlock - case Failed: return entry.neigh, nil, tcpip.ErrNoLinkAddress - default: panic(fmt.Sprintf("Invalid cache entry state: %s", s)) } diff --git a/pkg/tcpip/stack/neighbor_cache_test.go b/pkg/tcpip/stack/neighbor_cache_test.go index a0b7da5cd..fcd54ed83 100644 --- a/pkg/tcpip/stack/neighbor_cache_test.go +++ b/pkg/tcpip/stack/neighbor_cache_test.go @@ -1500,24 +1500,26 @@ func TestNeighborCacheReplace(t *testing.T) { } // Verify the entry exists - e, doneCh, err := neigh.entry(entry.Addr, entry.LocalAddr, linkRes, nil) - if err != nil { - t.Errorf("unexpected error from neigh.entry(%s, %s, _, nil): %s", entry.Addr, entry.LocalAddr, err) - } - if doneCh != nil { - t.Errorf("unexpected done channel from neigh.entry(%s, %s, _, nil): %v", entry.Addr, entry.LocalAddr, doneCh) - } - if t.Failed() { - t.FailNow() - } - want := NeighborEntry{ - Addr: entry.Addr, - LocalAddr: entry.LocalAddr, - LinkAddr: entry.LinkAddr, - State: Reachable, - } - if diff := cmp.Diff(e, want, entryDiffOpts()...); diff != "" { - t.Errorf("neigh.entry(%s, %s, _, nil) mismatch (-got, +want):\n%s", entry.Addr, entry.LinkAddr, diff) + { + e, doneCh, err := neigh.entry(entry.Addr, entry.LocalAddr, linkRes, nil) + if err != nil { + t.Errorf("unexpected error from neigh.entry(%s, %s, _, nil): %s", entry.Addr, entry.LocalAddr, err) + } + if doneCh != nil { + t.Errorf("unexpected done channel from neigh.entry(%s, %s, _, nil): %v", entry.Addr, entry.LocalAddr, doneCh) + } + if t.Failed() { + t.FailNow() + } + want := NeighborEntry{ + Addr: entry.Addr, + LocalAddr: entry.LocalAddr, + LinkAddr: entry.LinkAddr, + State: Reachable, + } + if diff := cmp.Diff(e, want, entryDiffOpts()...); diff != "" { + t.Errorf("neigh.entry(%s, %s, _, nil) mismatch (-got, +want):\n%s", entry.Addr, entry.LinkAddr, diff) + } } // Notify of a link address change @@ -1536,28 +1538,34 @@ func TestNeighborCacheReplace(t *testing.T) { IsRouter: false, }) - // Requesting the entry again should start address resolution + // Requesting the entry again should start neighbor reachability confirmation. + // + // Verify the entry's new link address and the new state. { - _, doneCh, err := neigh.entry(entry.Addr, entry.LocalAddr, linkRes, nil) - if err != tcpip.ErrWouldBlock { - t.Fatalf("got neigh.entry(%s, %s, _, nil) = %v, want = %s", entry.Addr, entry.LocalAddr, err, tcpip.ErrWouldBlock) + e, _, err := neigh.entry(entry.Addr, entry.LocalAddr, linkRes, nil) + if err != nil { + t.Fatalf("neigh.entry(%s, %s, _, nil): %s", entry.Addr, entry.LocalAddr, err) } - clock.Advance(config.DelayFirstProbeTime + typicalLatency) - select { - case <-doneCh: - default: - t.Fatalf("expected notification from done channel returned by neigh.entry(%s, %s, _, nil)", entry.Addr, entry.LocalAddr) + want := NeighborEntry{ + Addr: entry.Addr, + LocalAddr: entry.LocalAddr, + LinkAddr: updatedLinkAddr, + State: Delay, } + if diff := cmp.Diff(e, want, entryDiffOpts()...); diff != "" { + t.Errorf("neigh.entry(%s, %s, _, nil) mismatch (-got, +want):\n%s", entry.Addr, entry.LocalAddr, diff) + } + clock.Advance(config.DelayFirstProbeTime + typicalLatency) } - // Verify the entry's new link address + // Verify that the neighbor is now reachable. { e, _, err := neigh.entry(entry.Addr, entry.LocalAddr, linkRes, nil) clock.Advance(typicalLatency) if err != nil { t.Errorf("unexpected error from neigh.entry(%s, %s, _, nil): %s", entry.Addr, entry.LocalAddr, err) } - want = NeighborEntry{ + want := NeighborEntry{ Addr: entry.Addr, LocalAddr: entry.LocalAddr, LinkAddr: updatedLinkAddr, |