From 18fe2434db011ba8ba207a16d349f72cf098d4d9 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Maciej=20=C5=BBenczykowski?= Date: Fri, 1 Aug 2025 14:31:15 -0700 Subject: [PATCH] Lower tethering IPv6 MTU to 1400 (to match newly clamped RA) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Bug: 432676104 Test: TreeHugger Flag: EXEMPT mainline Signed-off-by: Maciej Żenczykowski Change-Id: I3674036bf28454bc57dcfeead9ff5f2917046939 --- .../com/android/networkstack/tethering/BpfCoordinator.java | 3 +-- .../android/networkstack/tethering/BpfCoordinatorTest.java | 5 ++--- 2 files changed, 3 insertions(+), 5 deletions(-) diff --git a/Tethering/src/com/android/networkstack/tethering/BpfCoordinator.java b/Tethering/src/com/android/networkstack/tethering/BpfCoordinator.java index 180791e813..57b7255ffd 100644 --- a/Tethering/src/com/android/networkstack/tethering/BpfCoordinator.java +++ b/Tethering/src/com/android/networkstack/tethering/BpfCoordinator.java @@ -1732,8 +1732,7 @@ public class BpfCoordinator { */ @NonNull public Tether6Value makeTether6Value() { - return new Tether6Value(upstreamIfindex, outDstMac, outSrcMac, ETH_P_IPV6, - NetworkStackConstants.ETHER_MTU); + return new Tether6Value(upstreamIfindex, outDstMac, outSrcMac, ETH_P_IPV6, 1400); } @Override 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 92ed6fc5b4..8183256da4 100644 --- a/Tethering/tests/unit/src/com/android/networkstack/tethering/BpfCoordinatorTest.java +++ b/Tethering/tests/unit/src/com/android/networkstack/tethering/BpfCoordinatorTest.java @@ -769,8 +769,7 @@ public class BpfCoordinatorTest { final TetherUpstream6Key key = new TetherUpstream6Key(DOWNSTREAM_IFACE_PARAMS.index, DOWNSTREAM_IFACE_PARAMS.macAddr, prefix64); final Tether6Value value = new Tether6Value(upstreamIfindex, - MacAddress.ALL_ZEROS_ADDRESS, MacAddress.ALL_ZEROS_ADDRESS, ETH_P_IPV6, - NetworkStackConstants.ETHER_MTU); + MacAddress.ALL_ZEROS_ADDRESS, MacAddress.ALL_ZEROS_ADDRESS, ETH_P_IPV6, 1400); expected.put(key, value); } ArgumentCaptor keyCaptor = @@ -1295,7 +1294,7 @@ public class BpfCoordinatorTest { assertEquals(MAC_NULL, value.ethDstMac); assertEquals(MAC_NULL, value.ethSrcMac); assertEquals(ETH_P_IPV6, value.ethProto); - assertEquals(NetworkStackConstants.ETHER_MTU, value.pmtu); + assertEquals(1400, value.pmtu); // oif (4) + ethDstMac (6) + ethSrcMac (6) + ethProto (2) + pmtu (2) = 20 assertEquals(20, value.writeToBytes().length); }