Fix endian error when pass upstream prefixes to bpf
TetherUpstream6Key#src64 should be stored in network order. Use
a big-endian ByteBuffer to retrieve a value stored in network order
is actually converts it into native order, which is little-endian in
Android.
In this CL, we changed it to use byte[] instead of long to store the
top 64-bits of the source prefix.
Test: atest TetheringTests
manual test with IPv6-only tethering upstream, check BPF stats.
Bug: 312072637
Change-Id: I79f9282d5eda28328aa6a764ea92b086d6285133
diff --git a/Tethering/src/com/android/networkstack/tethering/BpfCoordinator.java b/Tethering/src/com/android/networkstack/tethering/BpfCoordinator.java
index 4bd7e6a..9f542f4 100644
--- a/Tethering/src/com/android/networkstack/tethering/BpfCoordinator.java
+++ b/Tethering/src/com/android/networkstack/tethering/BpfCoordinator.java
@@ -90,7 +90,6 @@
import java.net.NetworkInterface;
import java.net.SocketException;
import java.net.UnknownHostException;
-import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
@@ -1258,12 +1257,18 @@
pw.decreaseIndent();
}
- private IpPrefix longToPrefix(long ip64) {
- final ByteBuffer prefixBuffer = ByteBuffer.allocate(IPV6_ADDR_LEN);
- prefixBuffer.putLong(ip64);
+ /**
+ * Returns a /64 IpPrefix corresponding to the passed in byte array
+ *
+ * @param ip64 byte array to convert format
+ * @return the converted IpPrefix
+ */
+ @VisibleForTesting
+ public static IpPrefix bytesToPrefix(final byte[] ip64) {
IpPrefix sourcePrefix;
+ byte[] prefixBytes = Arrays.copyOf(ip64, IPV6_ADDR_LEN);
try {
- sourcePrefix = new IpPrefix(InetAddress.getByAddress(prefixBuffer.array()), 64);
+ sourcePrefix = new IpPrefix(InetAddress.getByAddress(prefixBytes), 64);
} catch (UnknownHostException e) {
// Cannot happen. InetAddress.getByAddress can only throw an exception if the byte array
// is the wrong length, but we allocate it with fixed length IPV6_ADDR_LEN.
@@ -1274,7 +1279,7 @@
private String ipv6UpstreamRuleToString(TetherUpstream6Key key, Tether6Value value) {
return String.format("%d(%s) [%s] [%s] -> %d(%s) %04x [%s] [%s]",
- key.iif, getIfName(key.iif), key.dstMac, longToPrefix(key.src64), value.oif,
+ key.iif, getIfName(key.iif), key.dstMac, bytesToPrefix(key.src64), value.oif,
getIfName(value.oif), value.ethProto, value.ethSrcMac, value.ethDstMac);
}
@@ -1570,7 +1575,7 @@
*/
@NonNull
public TetherUpstream6Key makeTetherUpstream6Key() {
- long prefix64 = ByteBuffer.wrap(sourcePrefix.getRawAddress()).getLong();
+ final byte[] prefix64 = Arrays.copyOf(sourcePrefix.getRawAddress(), 8);
return new TetherUpstream6Key(downstreamIfindex, inDstMac, prefix64);
}
diff --git a/Tethering/src/com/android/networkstack/tethering/TetherUpstream6Key.java b/Tethering/src/com/android/networkstack/tethering/TetherUpstream6Key.java
index 36a1c3c..0cc3dd9 100644
--- a/Tethering/src/com/android/networkstack/tethering/TetherUpstream6Key.java
+++ b/Tethering/src/com/android/networkstack/tethering/TetherUpstream6Key.java
@@ -32,10 +32,10 @@
@Field(order = 1, type = Type.EUI48, padding = 6)
public final MacAddress dstMac; // Destination ethernet mac address (zeroed iff rawip ingress).
- @Field(order = 2, type = Type.S64)
- public final long src64; // The top 64-bits of the source ip.
+ @Field(order = 2, type = Type.ByteArray, arraysize = 8)
+ public final byte[] src64; // The top 64-bits of the source ip.
- public TetherUpstream6Key(int iif, @NonNull final MacAddress dstMac, long src64) {
+ public TetherUpstream6Key(int iif, @NonNull final MacAddress dstMac, final byte[] src64) {
Objects.requireNonNull(dstMac);
this.iif = iif;
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 6c1721e..01600b8 100644
--- a/Tethering/tests/unit/src/com/android/networkstack/tethering/BpfCoordinatorTest.java
+++ b/Tethering/tests/unit/src/com/android/networkstack/tethering/BpfCoordinatorTest.java
@@ -64,6 +64,7 @@
import static com.android.networkstack.tethering.TetheringConfiguration.DEFAULT_TETHER_OFFLOAD_POLL_INTERVAL_MS;
import static com.android.testutils.MiscAsserts.assertSameElements;
+import static org.junit.Assert.assertArrayEquals;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertNotNull;
@@ -166,7 +167,6 @@
import java.net.Inet4Address;
import java.net.Inet6Address;
import java.net.InetAddress;
-import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;
@@ -794,7 +794,7 @@
if (!mDeps.isAtLeastS()) return;
ArrayMap<TetherUpstream6Key, Tether6Value> expected = new ArrayMap<>();
for (IpPrefix upstreamPrefix : upstreamPrefixes) {
- long prefix64 = prefixToLong(upstreamPrefix);
+ final byte[] prefix64 = prefixToIp64(upstreamPrefix);
final TetherUpstream6Key key = new TetherUpstream6Key(DOWNSTREAM_IFACE_PARAMS.index,
DOWNSTREAM_IFACE_PARAMS.macAddr, prefix64);
final Tether6Value value = new Tether6Value(upstreamIfindex,
@@ -822,7 +822,7 @@
if (!mDeps.isAtLeastS()) return;
Set<TetherUpstream6Key> expected = new ArraySet<>();
for (IpPrefix upstreamPrefix : upstreamPrefixes) {
- long prefix64 = prefixToLong(upstreamPrefix);
+ final byte[] prefix64 = prefixToIp64(upstreamPrefix);
final TetherUpstream6Key key = new TetherUpstream6Key(DOWNSTREAM_IFACE_PARAMS.index,
DOWNSTREAM_IFACE_PARAMS.macAddr, prefix64);
expected.add(key);
@@ -1275,7 +1275,7 @@
}
@Test
- public void testRuleMakeTetherDownstream6Key() throws Exception {
+ public void testIpv6DownstreamRuleMakeTetherDownstream6Key() throws Exception {
final int mobileIfIndex = 100;
final Ipv6DownstreamRule rule = buildTestDownstreamRule(mobileIfIndex, NEIGH_A, MAC_A);
@@ -1288,7 +1288,7 @@
}
@Test
- public void testRuleMakeTether6Value() throws Exception {
+ public void testIpv6DownstreamRuleMakeTether6Value() throws Exception {
final int mobileIfIndex = 100;
final Ipv6DownstreamRule rule = buildTestDownstreamRule(mobileIfIndex, NEIGH_A, MAC_A);
@@ -1303,6 +1303,46 @@
}
@Test
+ public void testIpv6UpstreamRuleMakeTetherUpstream6Key() {
+ final byte[] bytes = new byte[]{(byte) 0x20, (byte) 0x01, (byte) 0x0d, (byte) 0xb8,
+ (byte) 0xab, (byte) 0xcd, (byte) 0xfe, (byte) 0x00};
+ final IpPrefix prefix = new IpPrefix("2001:db8:abcd:fe00::/64");
+ final Ipv6UpstreamRule rule = buildTestUpstreamRule(UPSTREAM_IFINDEX,
+ DOWNSTREAM_IFINDEX, prefix, DOWNSTREAM_MAC);
+
+ final TetherUpstream6Key key = rule.makeTetherUpstream6Key();
+ assertEquals(DOWNSTREAM_IFINDEX, key.iif);
+ assertEquals(DOWNSTREAM_MAC, key.dstMac);
+ assertArrayEquals(bytes, key.src64);
+ // iif (4) + dstMac (6) + padding (6) + src64 (8) = 24
+ assertEquals(24, key.writeToBytes().length);
+ }
+
+ @Test
+ public void testIpv6UpstreamRuleMakeTether6Value() {
+ final IpPrefix prefix = new IpPrefix("2001:db8:abcd:fe00::/64");
+ final Ipv6UpstreamRule rule = buildTestUpstreamRule(UPSTREAM_IFINDEX,
+ DOWNSTREAM_IFINDEX, prefix, DOWNSTREAM_MAC);
+
+ final Tether6Value value = rule.makeTether6Value();
+ assertEquals(UPSTREAM_IFINDEX, value.oif);
+ assertEquals(MAC_NULL, value.ethDstMac);
+ assertEquals(MAC_NULL, value.ethSrcMac);
+ assertEquals(ETH_P_IPV6, value.ethProto);
+ assertEquals(NetworkStackConstants.ETHER_MTU, value.pmtu);
+ // oif (4) + ethDstMac (6) + ethSrcMac (6) + ethProto (2) + pmtu (2) = 20
+ assertEquals(20, value.writeToBytes().length);
+ }
+
+ @Test
+ public void testBytesToPrefix() {
+ final byte[] bytes = new byte[]{(byte) 0x20, (byte) 0x01, (byte) 0x0d, (byte) 0xb8,
+ (byte) 0x00, (byte) 0x00, (byte) 0x12, (byte) 0x34};
+ final IpPrefix prefix = new IpPrefix("2001:db8:0:1234::/64");
+ assertEquals(prefix, BpfCoordinator.bytesToPrefix(bytes));
+ }
+
+ @Test
public void testSetDataLimit() throws Exception {
setupFunctioningNetdInterface();
@@ -2269,8 +2309,8 @@
100 /* nonzero, CT_NEW */);
}
- private static long prefixToLong(IpPrefix prefix) {
- return ByteBuffer.wrap(prefix.getRawAddress()).getLong();
+ private static byte[] prefixToIp64(IpPrefix prefix) {
+ return Arrays.copyOf(prefix.getRawAddress(), 8);
}
void checkRule4ExistInUpstreamDownstreamMap() throws Exception {
@@ -2515,7 +2555,7 @@
final Ipv6DownstreamRule rule = buildTestDownstreamRule(UPSTREAM_IFINDEX, NEIGH_A, MAC_A);
mBpfDownstream6Map.insertEntry(rule.makeTetherDownstream6Key(), rule.makeTether6Value());
- final long prefix64 = prefixToLong(UPSTREAM_PREFIX);
+ final byte[] prefix64 = prefixToIp64(UPSTREAM_PREFIX);
final TetherUpstream6Key upstream6Key = new TetherUpstream6Key(DOWNSTREAM_IFINDEX,
DOWNSTREAM_MAC, prefix64);
final Tether6Value upstream6Value = new Tether6Value(UPSTREAM_IFINDEX,