BpfCoordinator: avoid attach/deatach duplicate downstream program
The forwarding pairs may use the same downstream. Ex: 464xlat
tethering has rmnet0:ncm0, v4-rmnet0:ncm0 forwarding pairs.
Need to avoid duplicate downstream program.
Bug: 241106456
Test: atest BpfCoordinatorTest
Change-Id: Ic41b3ad856e4876808f8497a760081afcfd04988
diff --git a/Tethering/src/com/android/networkstack/tethering/BpfCoordinator.java b/Tethering/src/com/android/networkstack/tethering/BpfCoordinator.java
index 49442a6..f8169cb 100644
--- a/Tethering/src/com/android/networkstack/tethering/BpfCoordinator.java
+++ b/Tethering/src/com/android/networkstack/tethering/BpfCoordinator.java
@@ -905,10 +905,16 @@
if (forwardingPairExists(intIface, extIface)) return;
+ boolean firstUpstreamForThisDownstream = !isAnyForwardingPairOnDownstream(intIface);
boolean firstDownstreamForThisUpstream = !isAnyForwardingPairOnUpstream(extIface);
forwardingPairAdd(intIface, extIface);
- mBpfCoordinatorShim.attachProgram(intIface, UPSTREAM);
+ // Attach if the downstream is the first time to be used in a forwarding pair.
+ // Ex: IPv6 only interface has two forwarding pair, iface and v4-iface, on the
+ // same downstream.
+ if (firstUpstreamForThisDownstream) {
+ mBpfCoordinatorShim.attachProgram(intIface, UPSTREAM);
+ }
// Attach if the upstream is the first time to be used in a forwarding pair.
if (firstDownstreamForThisUpstream) {
mBpfCoordinatorShim.attachProgram(extIface, DOWNSTREAM);
@@ -922,7 +928,9 @@
forwardingPairRemove(intIface, extIface);
// Detaching program may fail because the interface has been removed already.
- mBpfCoordinatorShim.detachProgram(intIface);
+ if (!isAnyForwardingPairOnDownstream(intIface)) {
+ mBpfCoordinatorShim.detachProgram(intIface);
+ }
// Detach if no more forwarding pair is using the upstream.
if (!isAnyForwardingPairOnUpstream(extIface)) {
mBpfCoordinatorShim.detachProgram(extIface);
@@ -1827,6 +1835,13 @@
return mForwardingPairs.containsKey(extIface);
}
+ private boolean isAnyForwardingPairOnDownstream(@NonNull String intIface) {
+ for (final HashSet downstreams : mForwardingPairs.values()) {
+ if (downstreams.contains(intIface)) return true;
+ }
+ return false;
+ }
+
@NonNull
private NetworkStats buildNetworkStats(@NonNull StatsType type, int ifIndex,
@NonNull final ForwardedStats diff) {
diff --git a/Tethering/tests/unit/src/com/android/networkstack/tethering/BpfCoordinatorTest.java b/Tethering/tests/unit/src/com/android/networkstack/tethering/BpfCoordinatorTest.java
index fa1d881..788673a 100644
--- a/Tethering/tests/unit/src/com/android/networkstack/tethering/BpfCoordinatorTest.java
+++ b/Tethering/tests/unit/src/com/android/networkstack/tethering/BpfCoordinatorTest.java
@@ -1277,47 +1277,62 @@
try {
final String intIface1 = "wlan1";
final String intIface2 = "rndis0";
- final String extIface = "rmnet_data0";
+ final String extIface1 = "rmnet_data0";
+ final String extIface2 = "v4-rmnet_data0";
final String virtualIface = "ipsec0";
final BpfUtils mockMarkerBpfUtils = staticMockMarker(BpfUtils.class);
final BpfCoordinator coordinator = makeBpfCoordinator();
// [1] Add the forwarding pair <wlan1, rmnet_data0>. Expect that attach both wlan1 and
// rmnet_data0.
- coordinator.maybeAttachProgram(intIface1, extIface);
- ExtendedMockito.verify(() -> BpfUtils.attachProgram(extIface, DOWNSTREAM));
+ coordinator.maybeAttachProgram(intIface1, extIface1);
+ ExtendedMockito.verify(() -> BpfUtils.attachProgram(extIface1, DOWNSTREAM));
ExtendedMockito.verify(() -> BpfUtils.attachProgram(intIface1, UPSTREAM));
ExtendedMockito.verifyNoMoreInteractions(mockMarkerBpfUtils);
ExtendedMockito.clearInvocations(mockMarkerBpfUtils);
// [2] Add the forwarding pair <wlan1, rmnet_data0> again. Expect no more action.
- coordinator.maybeAttachProgram(intIface1, extIface);
+ coordinator.maybeAttachProgram(intIface1, extIface1);
ExtendedMockito.verifyNoMoreInteractions(mockMarkerBpfUtils);
ExtendedMockito.clearInvocations(mockMarkerBpfUtils);
// [3] Add the forwarding pair <rndis0, rmnet_data0>. Expect that attach rndis0 only.
- coordinator.maybeAttachProgram(intIface2, extIface);
+ coordinator.maybeAttachProgram(intIface2, extIface1);
ExtendedMockito.verify(() -> BpfUtils.attachProgram(intIface2, UPSTREAM));
ExtendedMockito.verifyNoMoreInteractions(mockMarkerBpfUtils);
ExtendedMockito.clearInvocations(mockMarkerBpfUtils);
- // [4] Remove the forwarding pair <rndis0, rmnet_data0>. Expect detach rndis0 only.
- coordinator.maybeDetachProgram(intIface2, extIface);
+ // [4] Add the forwarding pair <rndis0, v4-rmnet_data0>. Expect that attach
+ // v4-rmnet_data0 only.
+ coordinator.maybeAttachProgram(intIface2, extIface2);
+ ExtendedMockito.verify(() -> BpfUtils.attachProgram(extIface2, DOWNSTREAM));
+ ExtendedMockito.verifyNoMoreInteractions(mockMarkerBpfUtils);
+ ExtendedMockito.clearInvocations(mockMarkerBpfUtils);
+
+ // [5] Remove the forwarding pair <rndis0, v4-rmnet_data0>. Expect detach
+ // v4-rmnet_data0 only.
+ coordinator.maybeDetachProgram(intIface2, extIface2);
+ ExtendedMockito.verify(() -> BpfUtils.detachProgram(extIface2));
+ ExtendedMockito.verifyNoMoreInteractions(mockMarkerBpfUtils);
+ ExtendedMockito.clearInvocations(mockMarkerBpfUtils);
+
+ // [6] Remove the forwarding pair <rndis0, rmnet_data0>. Expect detach rndis0 only.
+ coordinator.maybeDetachProgram(intIface2, extIface1);
ExtendedMockito.verify(() -> BpfUtils.detachProgram(intIface2));
ExtendedMockito.verifyNoMoreInteractions(mockMarkerBpfUtils);
ExtendedMockito.clearInvocations(mockMarkerBpfUtils);
- // [5] Remove the forwarding pair <wlan1, rmnet_data0>. Expect that detach both wlan1
+ // [7] Remove the forwarding pair <wlan1, rmnet_data0>. Expect that detach both wlan1
// and rmnet_data0.
- coordinator.maybeDetachProgram(intIface1, extIface);
- ExtendedMockito.verify(() -> BpfUtils.detachProgram(extIface));
+ coordinator.maybeDetachProgram(intIface1, extIface1);
+ ExtendedMockito.verify(() -> BpfUtils.detachProgram(extIface1));
ExtendedMockito.verify(() -> BpfUtils.detachProgram(intIface1));
ExtendedMockito.verifyNoMoreInteractions(mockMarkerBpfUtils);
ExtendedMockito.clearInvocations(mockMarkerBpfUtils);
- // [6] Skip attaching if upstream is virtual interface.
+ // [8] Skip attaching if upstream is virtual interface.
coordinator.maybeAttachProgram(intIface1, virtualIface);
- ExtendedMockito.verify(() -> BpfUtils.attachProgram(extIface, DOWNSTREAM), never());
+ ExtendedMockito.verify(() -> BpfUtils.attachProgram(extIface1, DOWNSTREAM), never());
ExtendedMockito.verify(() -> BpfUtils.attachProgram(intIface1, UPSTREAM), never());
ExtendedMockito.verifyNoMoreInteractions(mockMarkerBpfUtils);
ExtendedMockito.clearInvocations(mockMarkerBpfUtils);