summaryrefslogtreecommitdiffhomepage
path: root/pkg/tcpip/stack
diff options
context:
space:
mode:
Diffstat (limited to 'pkg/tcpip/stack')
-rw-r--r--pkg/tcpip/stack/neighbor_cache.go2
-rw-r--r--pkg/tcpip/stack/neighbor_cache_test.go4
-rw-r--r--pkg/tcpip/stack/neighbor_entry.go22
3 files changed, 26 insertions, 2 deletions
diff --git a/pkg/tcpip/stack/neighbor_cache.go b/pkg/tcpip/stack/neighbor_cache.go
index 13ea2d1d9..0d3f626cf 100644
--- a/pkg/tcpip/stack/neighbor_cache.go
+++ b/pkg/tcpip/stack/neighbor_cache.go
@@ -233,6 +233,8 @@ func (n *neighborCache) addStaticEntry(addr tcpip.Address, linkAddr tcpip.LinkAd
}
// removeEntryLocked removes the specified entry from the neighbor cache.
+//
+// Prerequisite: n.mu and entry.mu MUST be locked.
func (n *neighborCache) removeEntryLocked(entry *neighborEntry) {
if entry.neigh.State != Static {
n.dynamic.lru.Remove(entry)
diff --git a/pkg/tcpip/stack/neighbor_cache_test.go b/pkg/tcpip/stack/neighbor_cache_test.go
index 0927122c2..732a299f7 100644
--- a/pkg/tcpip/stack/neighbor_cache_test.go
+++ b/pkg/tcpip/stack/neighbor_cache_test.go
@@ -80,7 +80,7 @@ func entryDiffOptsWithSort() []cmp.Option {
func newTestNeighborCache(nudDisp NUDDispatcher, config NUDConfigurations, clock tcpip.Clock) *neighborCache {
config.resetInvalidFields()
rng := rand.New(rand.NewSource(time.Now().UnixNano()))
- return &neighborCache{
+ neigh := &neighborCache{
nic: &NIC{
stack: &Stack{
clock: clock,
@@ -92,6 +92,8 @@ func newTestNeighborCache(nudDisp NUDDispatcher, config NUDConfigurations, clock
state: NewNUDState(config, rng),
cache: make(map[tcpip.Address]*neighborEntry, neighborCacheSize),
}
+ neigh.nic.neigh = neigh
+ return neigh
}
// testEntryStore contains a set of IP to NeighborEntry mappings.
diff --git a/pkg/tcpip/stack/neighbor_entry.go b/pkg/tcpip/stack/neighbor_entry.go
index 65fbd0ac3..32399b4f5 100644
--- a/pkg/tcpip/stack/neighbor_entry.go
+++ b/pkg/tcpip/stack/neighbor_entry.go
@@ -258,7 +258,7 @@ func (e *neighborEntry) setStateLocked(next NeighborState) {
case Failed:
e.notifyWakersLocked()
- e.job = e.nic.stack.newJob(&e.mu, func() {
+ e.job = e.nic.stack.newJob(&doubleLock{first: &e.nic.neigh.mu, second: &e.mu}, func() {
e.nic.neigh.removeEntryLocked(e)
})
e.job.Schedule(config.UnreachableTime)
@@ -512,3 +512,23 @@ func (e *neighborEntry) handleUpperLevelConfirmationLocked() {
panic(fmt.Sprintf("Invalid cache entry state: %s", e.neigh.State))
}
}
+
+// doubleLock combines two locks into one while maintaining lock ordering.
+//
+// TODO(gvisor.dev/issue/4796): Remove this once subsequent traffic to a Failed
+// neighbor is allowed.
+type doubleLock struct {
+ first, second sync.Locker
+}
+
+// Lock locks both locks in order: first then second.
+func (l *doubleLock) Lock() {
+ l.first.Lock()
+ l.second.Lock()
+}
+
+// Unlock unlocks both locks in reverse order: second then first.
+func (l *doubleLock) Unlock() {
+ l.second.Unlock()
+ l.first.Unlock()
+}