EthernetTetheringTest: add testTetherTcpV4
Bug: 237369591
Test: atest EthernetTetheringTest
Change-Id: I411ac8dc0a36413e2e65633375218b25c412e004
diff --git a/Tethering/tests/integration/src/android/net/EthernetTetheringTest.java b/Tethering/tests/integration/src/android/net/EthernetTetheringTest.java
index e694907..de788e7 100644
--- a/Tethering/tests/integration/src/android/net/EthernetTetheringTest.java
+++ b/Tethering/tests/integration/src/android/net/EthernetTetheringTest.java
@@ -28,6 +28,7 @@
import static android.net.TetheringManager.TETHERING_ETHERNET;
import static android.net.TetheringTester.TestDnsPacket;
import static android.net.TetheringTester.isExpectedIcmpPacket;
+import static android.net.TetheringTester.isExpectedTcpPacket;
import static android.net.TetheringTester.isExpectedUdpDnsPacket;
import static android.net.TetheringTester.isExpectedUdpPacket;
import static android.system.OsConstants.ICMP_ECHO;
@@ -35,6 +36,7 @@
import static android.system.OsConstants.IPPROTO_ICMP;
import static android.system.OsConstants.IPPROTO_IP;
import static android.system.OsConstants.IPPROTO_IPV6;
+import static android.system.OsConstants.IPPROTO_TCP;
import static android.system.OsConstants.IPPROTO_UDP;
import static com.android.net.module.util.ConnectivityUtils.isIPv6ULA;
@@ -50,6 +52,8 @@
import static com.android.net.module.util.NetworkStackConstants.IPV4_CHECKSUM_OFFSET;
import static com.android.net.module.util.NetworkStackConstants.IPV4_HEADER_MIN_LEN;
import static com.android.net.module.util.NetworkStackConstants.IPV4_LENGTH_OFFSET;
+import static com.android.net.module.util.NetworkStackConstants.TCPHDR_ACK;
+import static com.android.net.module.util.NetworkStackConstants.TCPHDR_SYN;
import static com.android.testutils.DeviceInfoUtils.KVersion;
import static com.android.testutils.TestNetworkTrackerKt.initTestNetwork;
import static com.android.testutils.TestPermissionUtil.runAsShell;
@@ -178,8 +182,11 @@
(Inet6Address) parseNumericAddress("2002:db8:1::515:ca");
private static final ByteBuffer TEST_REACHABILITY_PAYLOAD =
ByteBuffer.wrap(new byte[] { (byte) 0x55, (byte) 0xaa });
+ private static final ByteBuffer EMPTY_PAYLOAD = ByteBuffer.wrap(new byte[0]);
private static final short DNS_PORT = 53;
+ private static final short WINDOW = (short) 0x2000;
+ private static final short URGENT_POINTER = 0;
private static final String DUMPSYS_TETHERING_RAWMAP_ARG = "bpfRawMap";
private static final String DUMPSYS_RAWMAP_ARG_STATS = "--stats";
@@ -1771,6 +1778,138 @@
(short) udpHeader.srcPort, (short) dnsQuery.getHeader().id, tester);
}
+ @NonNull
+ private ByteBuffer buildTcpPacket(
+ @Nullable final MacAddress srcMac, @Nullable final MacAddress dstMac,
+ @NonNull final InetAddress srcIp, @NonNull final InetAddress dstIp,
+ short srcPort, short dstPort, final short seq, final short ack,
+ final byte tcpFlags, @NonNull final ByteBuffer payload) throws Exception {
+ // TODO: support IPv6
+ if (!(srcIp instanceof Inet4Address && dstIp instanceof Inet4Address)) {
+ fail("Unsupported conditions: srcIp " + srcIp + ", dstIp " + dstIp);
+ return null;
+ }
+
+ final boolean hasEther = (srcMac != null && dstMac != null);
+ final ByteBuffer buffer = PacketBuilder.allocate(hasEther, IPPROTO_IP, IPPROTO_TCP,
+ payload.limit());
+ final PacketBuilder packetBuilder = new PacketBuilder(buffer);
+
+ // [1] Ethernet header
+ if (hasEther) packetBuilder.writeL2Header(srcMac, dstMac, (short) ETHER_TYPE_IPV4);
+
+ // [2] IP header
+ packetBuilder.writeIpv4Header(TYPE_OF_SERVICE, ID, FLAGS_AND_FRAGMENT_OFFSET,
+ TIME_TO_LIVE, (byte) IPPROTO_TCP, (Inet4Address) srcIp, (Inet4Address) dstIp);
+
+ // [3] TCP header
+ packetBuilder.writeTcpHeader(srcPort, dstPort, seq, ack, tcpFlags, WINDOW, URGENT_POINTER);
+
+ // [4] Payload
+ buffer.put(payload);
+ // in case data might be reused by caller, restore the position and
+ // limit of bytebuffer.
+ payload.clear();
+
+ return packetBuilder.finalizePacket();
+ }
+
+ private void sendDownloadPacketTcp(@NonNull final InetAddress srcIp,
+ @NonNull final InetAddress dstIp, short seq, short ack, byte tcpFlags,
+ @NonNull final ByteBuffer payload, @NonNull final TetheringTester tester)
+ throws Exception {
+ final ByteBuffer testPacket = buildTcpPacket(null /* srcMac */, null /* dstMac */,
+ srcIp, dstIp, REMOTE_PORT /* srcPort */, LOCAL_PORT /* dstPort */, seq, ack,
+ tcpFlags, payload);
+ tester.verifyDownload(testPacket, p -> {
+ Log.d(TAG, "Packet in downstream: " + dumpHexString(p));
+
+ return isExpectedTcpPacket(p, true /* hasEther */, true /* isIpv4 */, seq,
+ payload);
+ });
+ }
+
+ private void sendUploadPacketTcp(@NonNull final MacAddress srcMac,
+ @NonNull final MacAddress dstMac, @NonNull final InetAddress srcIp,
+ @NonNull final InetAddress dstIp, short seq, short ack, byte tcpFlags,
+ @NonNull final ByteBuffer payload, @NonNull final TetheringTester tester)
+ throws Exception {
+ final ByteBuffer testPacket = buildTcpPacket(srcMac, dstMac, srcIp, dstIp,
+ LOCAL_PORT /* srcPort */, REMOTE_PORT /* dstPort */, seq, ack, tcpFlags,
+ payload);
+ tester.verifyUpload(testPacket, p -> {
+ Log.d(TAG, "Packet in upstream: " + dumpHexString(p));
+
+ return isExpectedTcpPacket(p, false /* hasEther */, true /* isIpv4 */,
+ seq, payload);
+ });
+ }
+
+ void runTcpTest(@NonNull final MacAddress srcMac, @NonNull final MacAddress dstMac,
+ @NonNull final InetAddress remoteIp, @NonNull final InetAddress tetheringUpstreamIp,
+ @NonNull final InetAddress clientIp, @NonNull final TetheringTester tester)
+ throws Exception {
+ // Three way handshake and data transfer.
+ //
+ // Server (base seq = 2000) Client (base seq = 1000)
+ // | |
+ // | [1] [SYN] SEQ = 1000 |
+ // |<---------------------------------------------------------| -
+ // | | ^
+ // | [2] [SYN + ACK] SEQ = 2000, ACK = 1000+1 | |
+ // |--------------------------------------------------------->| three way handshake
+ // | | |
+ // | [3] [ACK] SEQ = 1001, ACK = 2000+1 | v
+ // |<---------------------------------------------------------| -
+ // | | ^
+ // | [4] [ACK] SEQ = 1001, ACK = 2001, 2 byte payload | |
+ // |<---------------------------------------------------------| data transfer
+ // | | |
+ // | [5] [ACK] SEQ = 2001, ACK = 1001+2, 2 byte payload | v
+ // |--------------------------------------------------------->| -
+ // | |
+ //
+
+ // This test can only verify the packets are transferred end to end but TCP state.
+ // TODO: verify TCP state change via /proc/net/nf_conntrack or netlink conntrack event.
+ // [1] [UPLOAD] [SYN]: SEQ = 1000
+ sendUploadPacketTcp(srcMac, dstMac, clientIp, remoteIp, (short) 1000 /* seq */,
+ (short) 0 /* ack */, TCPHDR_SYN, EMPTY_PAYLOAD, tester);
+
+ // [2] [DONWLOAD] [SYN + ACK]: SEQ = 2000, ACK = 1001
+ sendDownloadPacketTcp(remoteIp, tetheringUpstreamIp, (short) 2000 /* seq */,
+ (short) 1001 /* ack */, (byte) ((TCPHDR_SYN | TCPHDR_ACK) & 0xff),
+ EMPTY_PAYLOAD, tester);
+
+ // [3] [UPLOAD] [ACK]: SEQ = 1001, ACK = 2001
+ sendUploadPacketTcp(srcMac, dstMac, clientIp, remoteIp, (short) 1001 /* seq */,
+ (short) 2001 /* ack */, TCPHDR_ACK, EMPTY_PAYLOAD, tester);
+
+ // [4] [UPLOAD] [ACK]: SEQ = 1001, ACK = 2001, 2 byte payload
+ sendUploadPacketTcp(srcMac, dstMac, clientIp, remoteIp, (short) 1001 /* seq */,
+ (short) 2001 /* ack */, TCPHDR_ACK, TX_PAYLOAD, tester);
+
+ // [5] [DONWLOAD] [ACK]: SEQ = 2001, ACK = 1003, 2 byte payload
+ sendDownloadPacketTcp(remoteIp, tetheringUpstreamIp, (short) 2001 /* seq */,
+ (short) 1003 /* ack */, TCPHDR_ACK, RX_PAYLOAD, tester);
+ }
+
+ @Test
+ public void testTetherTcpV4() throws Exception {
+ final TetheringTester tester = initTetheringTester(toList(TEST_IP4_ADDR),
+ toList(TEST_IP4_DNS));
+ final TetheredDevice tethered = tester.createTetheredDevice(TEST_MAC, false /* hasIpv6 */);
+
+ // TODO: remove the connectivity verification for upstream connected notification race.
+ // See the same reason in runUdp4Test().
+ probeV4TetheringConnectivity(tester, tethered, false /* is4To6 */);
+
+ runTcpTest(tethered.macAddr /* srcMac */, tethered.routerMacAddr /* dstMac */,
+ REMOTE_IP4_ADDR /* remoteIp */,
+ TEST_IP4_ADDR.getAddress() /* tetheringUpstreamIp */,
+ tethered.ipv4Addr /* clientIp */, tester);
+ }
+
private <T> List<T> toList(T... array) {
return Arrays.asList(array);
}
diff --git a/Tethering/tests/integration/src/android/net/TetheringTester.java b/Tethering/tests/integration/src/android/net/TetheringTester.java
index d2e3512..ae39b24 100644
--- a/Tethering/tests/integration/src/android/net/TetheringTester.java
+++ b/Tethering/tests/integration/src/android/net/TetheringTester.java
@@ -19,6 +19,7 @@
import static android.net.InetAddresses.parseNumericAddress;
import static android.system.OsConstants.IPPROTO_ICMP;
import static android.system.OsConstants.IPPROTO_ICMPV6;
+import static android.system.OsConstants.IPPROTO_TCP;
import static android.system.OsConstants.IPPROTO_UDP;
import static com.android.net.module.util.DnsPacket.ANSECTION;
@@ -40,6 +41,7 @@
import static com.android.net.module.util.NetworkStackConstants.IPV6_ADDR_ALL_NODES_MULTICAST;
import static com.android.net.module.util.NetworkStackConstants.NEIGHBOR_ADVERTISEMENT_FLAG_OVERRIDE;
import static com.android.net.module.util.NetworkStackConstants.NEIGHBOR_ADVERTISEMENT_FLAG_SOLICITED;
+import static com.android.net.module.util.NetworkStackConstants.TCPHDR_SYN;
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.fail;
@@ -66,6 +68,7 @@
import com.android.net.module.util.structs.NsHeader;
import com.android.net.module.util.structs.PrefixInformationOption;
import com.android.net.module.util.structs.RaHeader;
+import com.android.net.module.util.structs.TcpHeader;
import com.android.net.module.util.structs.UdpHeader;
import com.android.networkstack.arp.ArpPacket;
import com.android.testutils.TapPacketReader;
@@ -589,6 +592,42 @@
return true;
}
+
+ private static boolean isTcpSynPacket(@NonNull final TcpHeader tcpHeader) {
+ return (tcpHeader.dataOffsetAndControlBits & TCPHDR_SYN) != 0;
+ }
+
+ public static boolean isExpectedTcpPacket(@NonNull final byte[] rawPacket, boolean hasEth,
+ boolean isIpv4, int seq, @NonNull final ByteBuffer payload) {
+ final ByteBuffer buf = ByteBuffer.wrap(rawPacket);
+ try {
+ if (hasEth && !hasExpectedEtherHeader(buf, isIpv4)) return false;
+
+ if (!hasExpectedIpHeader(buf, isIpv4, IPPROTO_TCP)) return false;
+
+ final TcpHeader tcpHeader = Struct.parse(TcpHeader.class, buf);
+ if (tcpHeader.seq != seq) return false;
+
+ // Don't try to parse the payload if it is a TCP SYN segment because additional TCP
+ // option MSS may be added in the SYN segment. Currently, TetherController uses
+ // iptables to limit downstream MSS for IPv4. The additional TCP options will be
+ // misunderstood as payload because parsing TCP options are not supported by class
+ // TcpHeader for now. See TetherController::setupIptablesHooks.
+ // TODO: remove once TcpHeader supports parsing TCP options.
+ if (isTcpSynPacket(tcpHeader)) {
+ Log.d(TAG, "Found SYN segment. Ignore parsing the remaining part of packet.");
+ return true;
+ }
+
+ if (payload.limit() != buf.remaining()) return false;
+ return Arrays.equals(getRemaining(buf), getRemaining(payload.asReadOnlyBuffer()));
+ } catch (Exception e) {
+ // Parsing packet fail means it is not tcp packet.
+ }
+
+ return false;
+ }
+
private void sendUploadPacket(ByteBuffer packet) throws Exception {
mDownstreamReader.sendResponse(packet);
}