Stop reducing RA advertised ipv6 mtu by 16 - not needed.
This effectively reverts:
commit da0fb1bca8eda1ce8159289a2ea9e4f6933ce517
Author: Maciej Żenczykowski <maze@google.com>
Date: Wed Feb 19 01:24:39 2020 -0800
Reduce advertised ipv6 mtu by 16 to fit ethernet header
This is a temporary hack to workaround the inability of current
kernel's ebpf bpf_skb_change_mode() function to prefix a 14-byte
ethernet header on to a packet without going over the upstream
(source, rawip) interface's mtu *before* we bpf_redirect() to
the downstream (destination, ethernet) interface.
Test: build, atest, atest TetheringTests
Bug: 149816401
Test: flashed a flame with new kernel and it works at 1500 mtu
Bug: 149816401
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I76a75a16fa27b47d78816b2f9379ef4bb68beb00
diff --git a/Tethering/src/android/net/ip/IpServer.java b/Tethering/src/android/net/ip/IpServer.java
index 659d344..6edc0e6 100644
--- a/Tethering/src/android/net/ip/IpServer.java
+++ b/Tethering/src/android/net/ip/IpServer.java
@@ -753,12 +753,7 @@
final String upstreamIface = v6only.getInterfaceName();
params = new RaParams();
- // When BPF offload is enabled, we advertise an mtu lower by 16, which is the closest
- // multiple of 8 >= 14, the ethernet header size. This makes kernel ebpf tethering
- // offload happy. This hack should be reverted once we have the kernel fixed up.
- // Note: this will automatically clamp to at least 1280 (ipv6 minimum mtu)
- // see RouterAdvertisementDaemon.java putMtu()
- params.mtu = mUsingBpfOffload ? v6only.getMtu() - 16 : v6only.getMtu();
+ params.mtu = v6only.getMtu();
params.hasDefaultRoute = v6only.hasIpv6DefaultRoute();
if (params.hasDefaultRoute) params.hopLimit = getHopLimit(upstreamIface, ttlAdjustment);