diff options
| author | Ghanan Gowripalan <ghanan@google.com> | 2021-01-13 17:09:44 -0800 |
|---|---|---|
| committer | gVisor bot <gvisor-bot@google.com> | 2021-01-13 17:12:29 -0800 |
| commit | c49ce8ca8ab988fd548419c522caf45bda90317b (patch) | |
| tree | 3429eeeac9831c59d40f17e6a15527767eca0e4e /pkg/tcpip/stack/nic.go | |
| parent | 25b5ec7135a6de80674ac1ad4d2289c29e156f42 (diff) | |
Clear neighbor table on NIC down
Note, this includes static entries to match linux's behaviour.
```
$ ip neigh show dev eth0
192.168.42.1 lladdr fc:ec:da:70:6e:f9 STALE
$ sudo ip neigh add 192.168.42.172 lladdr 22:33:44:55:66:77 dev eth0
$ ip neigh show dev eth0
192.168.42.1 lladdr fc:ec:da:70:6e:f9 STALE
192.168.42.172 lladdr 22:33:44:55:66:77 PERMANENT
$ sudo ifconfig eth0 down
$ ip neigh show dev eth0
$ sudo ifconfig eth0 up
$ ip neigh show dev eth0
```
Test: stack_test.TestClearNeighborCacheOnNICDisable
PiperOrigin-RevId: 351696306
Diffstat (limited to 'pkg/tcpip/stack/nic.go')
| -rw-r--r-- | pkg/tcpip/stack/nic.go | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/pkg/tcpip/stack/nic.go b/pkg/tcpip/stack/nic.go index 4a34805b5..8a946b4fa 100644 --- a/pkg/tcpip/stack/nic.go +++ b/pkg/tcpip/stack/nic.go @@ -217,6 +217,16 @@ func (n *NIC) disableLocked() { ep.Disable() } + // Clear the neighbour table (including static entries) as we cannot guarantee + // that the current neighbour table will be valid when the NIC is enabled + // again. + // + // This matches linux's behaviour at the time of writing: + // https://github.com/torvalds/linux/blob/71c061d2443814de15e177489d5cc00a4a253ef3/net/core/neighbour.c#L371 + if err := n.clearNeighbors(); err != nil && err != tcpip.ErrNotSupported { + panic(fmt.Sprintf("n.clearNeighbors(): %s", err)) + } + if !n.setEnabled(false) { panic("should have only done work to disable the NIC if it was enabled") } |