Add an integration test to verify zero-length DHCP packet.
DHCP packet listener closes the listening socket and stops reading
packet upon receiving a zero-length DHCP packet, which will break
the following DHCP handshake. Add an integration test to verify the
current behavior. A follow-up fix will verify if DHCP server will
accept the zero-length DHCP packet and continue reading packet on
that socket.
Bug: 269692093
Test: atest TetheringIntegrationTests
Change-Id: I5990e37cdfad4e8e4337b0bb1a74632286884baf
diff --git a/Tethering/tests/integration/base/android/net/TetheringTester.java b/Tethering/tests/integration/base/android/net/TetheringTester.java
index ae39b24..1c0803e 100644
--- a/Tethering/tests/integration/base/android/net/TetheringTester.java
+++ b/Tethering/tests/integration/base/android/net/TetheringTester.java
@@ -628,7 +628,7 @@
return false;
}
- private void sendUploadPacket(ByteBuffer packet) throws Exception {
+ public void sendUploadPacket(ByteBuffer packet) throws Exception {
mDownstreamReader.sendResponse(packet);
}
@@ -680,4 +680,12 @@
return verifyPacketNotNull("Download fail", getDownloadPacket(filter));
}
+
+ // Send DHCPDISCOVER to DHCP server to see if DHCP server is still alive to handle
+ // the upcoming DHCP packets. This method should be only used when we know the DHCP
+ // server has been created successfully before.
+ public boolean testDhcpServerAlive(final MacAddress mac) throws Exception {
+ sendDhcpDiscover(mac.toByteArray());
+ return getNextDhcpPacket() != null;
+ }
}
diff --git a/Tethering/tests/integration/src/android/net/EthernetTetheringTest.java b/Tethering/tests/integration/src/android/net/EthernetTetheringTest.java
index 55854e2..21927df 100644
--- a/Tethering/tests/integration/src/android/net/EthernetTetheringTest.java
+++ b/Tethering/tests/integration/src/android/net/EthernetTetheringTest.java
@@ -39,6 +39,7 @@
import static com.android.net.module.util.NetworkStackConstants.IPV4_LENGTH_OFFSET;
import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.assertTrue;
import static org.junit.Assert.fail;
@@ -839,4 +840,41 @@
REMOTE_NAT64_ADDR /* downloadSrcIp */, clatIp6 /* downloadDstIp */,
tester, true /* isClat */);
}
+
+ private static final byte[] ZeroLengthDhcpPacket = new byte[] {
+ // scapy.Ether(
+ // dst="ff:ff:ff:ff:ff:ff")
+ // scapy.IP(
+ // dst="255.255.255.255")
+ // scapy.UDP(sport=68, dport=67)
+ /* Ethernet Header */
+ (byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0xff, (byte) 0xff,
+ (byte) 0xe0, (byte) 0x4f, (byte) 0x43, (byte) 0xe6, (byte) 0xfb, (byte) 0xd2,
+ (byte) 0x08, (byte) 0x00,
+ /* Ip header */
+ (byte) 0x45, (byte) 0x00, (byte) 0x00, (byte) 0x1c, (byte) 0x00, (byte) 0x01,
+ (byte) 0x00, (byte) 0x00, (byte) 0x40, (byte) 0x11, (byte) 0xb6, (byte) 0x58,
+ (byte) 0x64, (byte) 0x4f, (byte) 0x60, (byte) 0x29, (byte) 0xff, (byte) 0xff,
+ (byte) 0xff, (byte) 0xff,
+ /* UDP header */
+ (byte) 0x00, (byte) 0x44, (byte) 0x00, (byte) 0x43,
+ (byte) 0x00, (byte) 0x08, (byte) 0x3a, (byte) 0xdf
+ };
+
+ @Test
+ public void testTetherZeroLengthDhcpPacket() throws Exception {
+ final TetheringTester tester = initTetheringTester(toList(TEST_IP4_ADDR),
+ toList(TEST_IP4_DNS));
+ tester.createTetheredDevice(TEST_MAC, false /* hasIpv6 */);
+
+ // Send a zero-length DHCP packet to upstream DHCP server.
+ final ByteBuffer packet = ByteBuffer.wrap(ZeroLengthDhcpPacket);
+ tester.sendUploadPacket(packet);
+
+ // Send DHCPDISCOVER packet from another downstream tethered device to verify that upstream
+ // DHCP server has closed the listening socket and stopped reading, then we will not receive
+ // any DHCPOFFER in this case.
+ final MacAddress macAddress = MacAddress.fromString("11:22:33:44:55:66");
+ assertFalse(tester.testDhcpServerAlive(macAddress));
+ }
}