| /* |
| * Copyright (C) 2020 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package android.net.util |
| |
| import android.Manifest.permission.MANAGE_TEST_NETWORKS |
| import android.content.Context |
| import android.net.InetAddresses.parseNumericAddress |
| import android.net.IpPrefix |
| import android.net.MacAddress |
| import android.net.TestNetworkInterface |
| import android.net.TestNetworkManager |
| import android.net.dhcp.DhcpPacket |
| import android.os.HandlerThread |
| import android.system.ErrnoException |
| import android.system.Os |
| import android.system.OsConstants |
| import android.system.OsConstants.AF_INET |
| import android.system.OsConstants.AF_PACKET |
| import android.system.OsConstants.ETH_P_IPV6 |
| import android.system.OsConstants.IPPROTO_UDP |
| import android.system.OsConstants.SOCK_CLOEXEC |
| import android.system.OsConstants.SOCK_DGRAM |
| import android.system.OsConstants.SOCK_NONBLOCK |
| import android.system.OsConstants.SOCK_RAW |
| import android.system.OsConstants.SOL_SOCKET |
| import android.system.OsConstants.SO_RCVTIMEO |
| import android.system.StructTimeval |
| import androidx.test.platform.app.InstrumentationRegistry |
| import com.android.internal.util.HexDump |
| import com.android.net.module.util.InterfaceParams |
| import com.android.net.module.util.IpUtils |
| import com.android.net.module.util.Ipv6Utils |
| import com.android.net.module.util.NetworkStackConstants.ETHER_ADDR_LEN |
| import com.android.net.module.util.NetworkStackConstants.ETHER_HEADER_LEN |
| import com.android.net.module.util.NetworkStackConstants.IPV4_ADDR_ANY |
| import com.android.net.module.util.NetworkStackConstants.IPV4_CHECKSUM_OFFSET |
| import com.android.net.module.util.NetworkStackConstants.IPV4_FLAGS_OFFSET |
| import com.android.net.module.util.NetworkStackConstants.IPV4_FLAG_DF |
| import com.android.net.module.util.NetworkStackConstants.IPV4_FLAG_MF |
| import com.android.net.module.util.NetworkStackConstants.IPV4_HEADER_MIN_LEN |
| import com.android.net.module.util.NetworkStackConstants.IPV6_ADDR_ALL_NODES_MULTICAST |
| import com.android.net.module.util.NetworkStackConstants.UDP_HEADER_LEN |
| import com.android.net.module.util.structs.PrefixInformationOption |
| import com.android.networkstack.util.NetworkStackUtils |
| import com.android.testutils.ArpRequestFilter |
| import com.android.testutils.IPv4UdpFilter |
| import com.android.testutils.PollPacketReader |
| import java.io.FileDescriptor |
| import java.net.Inet4Address |
| import java.net.Inet6Address |
| import java.net.InetAddress |
| import java.nio.ByteBuffer |
| import java.util.Arrays |
| import kotlin.reflect.KClass |
| import kotlin.test.assertEquals |
| import kotlin.test.assertNotNull |
| import kotlin.test.assertNull |
| import kotlin.test.assertTrue |
| import kotlin.test.fail |
| import org.junit.After |
| import org.junit.Assert.assertArrayEquals |
| import org.junit.Before |
| import org.junit.Test |
| |
| class NetworkStackUtilsIntegrationTest { |
| private val inst by lazy { InstrumentationRegistry.getInstrumentation() } |
| private val context by lazy { inst.context } |
| |
| private val TEST_TIMEOUT_MS = 10_000L |
| private val TEST_MTU = 1500 |
| private val TEST_TARGET_IPV4_ADDR = parseNumericAddress("192.0.2.42") as Inet4Address |
| private val TEST_SRC_MAC = MacAddress.fromString("BA:98:76:54:32:10") |
| private val TEST_TARGET_MAC = MacAddress.fromString("01:23:45:67:89:0A") |
| private val TEST_INET6ADDR_1 = parseNumericAddress("2001:db8::1") as Inet6Address |
| private val TEST_INET6ADDR_2 = parseNumericAddress("2001:db8::2") as Inet6Address |
| private val TEST_INET6ADDR_3 = parseNumericAddress("fd01:db8::3") as Inet6Address |
| |
| // RFC4291 section 2.7.1 |
| private val SOLICITED_NODE_MULTICAST_PREFIX = "FF02:0:0:0:0:1:FF00::/104" |
| |
| private val readerHandler = HandlerThread( |
| NetworkStackUtilsIntegrationTest::class.java.simpleName) |
| private lateinit var iface: TestNetworkInterface |
| private lateinit var reader: PollPacketReader |
| |
| @Before |
| fun setUp() { |
| inst.uiAutomation.adoptShellPermissionIdentity(MANAGE_TEST_NETWORKS) |
| try { |
| val tnm = context.assertHasService(TestNetworkManager::class) |
| iface = tnm.createTapInterface() |
| } finally { |
| inst.uiAutomation.dropShellPermissionIdentity() |
| } |
| readerHandler.start() |
| reader = PollPacketReader(readerHandler.threadHandler, iface.fileDescriptor.fileDescriptor, |
| 1500 /* maxPacketSize */) |
| readerHandler.threadHandler.post { reader.start() } |
| } |
| |
| @After |
| fun tearDown() { |
| readerHandler.quitSafely() |
| if (this::iface.isInitialized) iface.fileDescriptor.close() |
| } |
| |
| @Test |
| fun testAddArpEntry() { |
| val socket = Os.socket(AF_INET, SOCK_DGRAM or SOCK_NONBLOCK, IPPROTO_UDP) |
| SocketUtils.bindSocketToInterface(socket, iface.interfaceName) |
| |
| NetworkStackUtils.addArpEntry(TEST_TARGET_IPV4_ADDR, TEST_TARGET_MAC, iface.interfaceName, |
| socket) |
| |
| // Fake DHCP packet: would not be usable as a DHCP offer (most IPv4 addresses are all-zero, |
| // no gateway or DNS servers, etc). |
| // Using a DHCP packet to replicate actual usage of the API: it is used in DhcpServer to |
| // send packets to clients before their IP address has been assigned. |
| val buffer = DhcpPacket.buildOfferPacket(DhcpPacket.ENCAP_BOOTP, 123 /* transactionId */, |
| false /* broadcast */, IPV4_ADDR_ANY /* serverIpAddr */, |
| IPV4_ADDR_ANY /* relayIp */, IPV4_ADDR_ANY /* yourIp */, |
| TEST_TARGET_MAC.toByteArray(), 3600 /* timeout */, IPV4_ADDR_ANY /* netMask */, |
| IPV4_ADDR_ANY /* bcAddr */, emptyList<Inet4Address>() /* gateways */, |
| emptyList<Inet4Address>() /* dnsServers */, |
| IPV4_ADDR_ANY /* dhcpServerIdentifier */, null /* domainName */, |
| null /* hostname */, false /* metered */, 1500 /* mtu */, |
| null /* captivePortalUrl */) |
| // Not using .array as per errorprone "ByteBufferBackingArray" recommendation |
| val originalPacket = buffer.readAsArray() |
| |
| Os.sendto(socket, originalPacket, 0 /* bytesOffset */, originalPacket.size /* bytesCount */, |
| 0 /* flags */, TEST_TARGET_IPV4_ADDR, DhcpPacket.DHCP_CLIENT.toInt() /* port */) |
| |
| // Verify the packet was sent to the mac address specified in the ARP entry |
| // Also accept ARP requests, but expect that none is sent before the UDP packet |
| // IPv6 NS may be sent on the interface but will be filtered out |
| val sentPacket = reader.poll(TEST_TIMEOUT_MS, IPv4UdpFilter().or(ArpRequestFilter())) |
| ?: fail("Packet was not sent on the interface") |
| |
| val sentTargetAddr = MacAddress.fromBytes(sentPacket.copyOfRange(0, ETHER_ADDR_LEN)) |
| assertEquals(TEST_TARGET_MAC, sentTargetAddr, "Destination ethernet address does not match") |
| |
| val sentDhcpPacket = sentPacket.copyOfRange( |
| ETHER_HEADER_LEN + IPV4_HEADER_MIN_LEN + UDP_HEADER_LEN, sentPacket.size) |
| |
| assertArrayEquals("Sent packet != original packet", originalPacket, sentDhcpPacket) |
| } |
| |
| private fun doTestAttachRaFilter(generic: Boolean) { |
| val socket = Os.socket(AF_PACKET, SOCK_RAW or SOCK_CLOEXEC, 0) |
| val ifParams = InterfaceParams.getByName(iface.interfaceName) |
| ?: fail("Could not obtain interface params for ${iface.interfaceName}") |
| val socketAddr = SocketUtils.makePacketSocketAddress(ETH_P_IPV6, ifParams.index) |
| Os.bind(socket, socketAddr) |
| Os.setsockoptTimeval(socket, SOL_SOCKET, SO_RCVTIMEO, |
| StructTimeval.fromMillis(TEST_TIMEOUT_MS)) |
| |
| // Verify that before setting any filter, the socket receives pings |
| val echo = Ipv6Utils.buildEchoRequestPacket(TEST_SRC_MAC, TEST_TARGET_MAC, TEST_INET6ADDR_1, |
| TEST_INET6ADDR_2) |
| reader.sendResponse(echo) |
| echo.rewind() |
| assertNextPacketEquals(socket, echo.readAsArray(), "ICMPv6 echo") |
| |
| if (generic) { |
| NetworkStackUtils.attachControlPacketFilter(socket) |
| } else { |
| NetworkStackUtils.attachRaFilter(socket) |
| } |
| // Send another echo, then an RA. After setting the filter expect only the RA. |
| echo.rewind() |
| reader.sendResponse(echo) |
| val pio = PrefixInformationOption.build(IpPrefix("2001:db8:1::/64"), |
| 0.toByte() /* flags */, 3600 /* validLifetime */, 1800 /* preferredLifetime */) |
| val ra = Ipv6Utils.buildRaPacket(TEST_SRC_MAC, TEST_TARGET_MAC, |
| TEST_INET6ADDR_1 /* routerAddr */, IPV6_ADDR_ALL_NODES_MULTICAST, |
| 0.toByte() /* flags */, 1800 /* lifetime */, 0 /* reachableTime */, |
| 0 /* retransTimer */, pio) |
| reader.sendResponse(ra) |
| ra.rewind() |
| |
| assertNextPacketEquals(socket, ra.readAsArray(), "ICMPv6 RA") |
| } |
| |
| @Test |
| fun testAttachRaFilter() { |
| doTestAttachRaFilter(false) |
| } |
| |
| @Test |
| fun testRaViaAttachControlPacketFilter() { |
| doTestAttachRaFilter(true) |
| } |
| |
| private fun assertNextPacketEquals(socket: FileDescriptor, expected: ByteArray, descr: String) { |
| val buffer = ByteArray(TEST_MTU) |
| val readPacket = Os.read(socket, buffer, 0 /* byteOffset */, buffer.size) |
| assertTrue(readPacket > 0, "$descr not received") |
| assertEquals(expected.size, readPacket, "Received packet size does not match for $descr") |
| assertArrayEquals("Received packet != expected $descr", |
| expected, buffer.copyOfRange(0, readPacket)) |
| } |
| |
| private fun assertSolicitedNodeMulticastAddress( |
| expected: Inet6Address?, |
| unicast: Inet6Address |
| ) { |
| assertNotNull(expected) |
| val prefix = IpPrefix(SOLICITED_NODE_MULTICAST_PREFIX) |
| assertTrue(prefix.contains(expected)) |
| assertTrue(expected.isMulticastAddress()) |
| // check the last 3 bytes of address |
| assertArrayEquals(Arrays.copyOfRange(expected.getAddress(), 13, 15), |
| Arrays.copyOfRange(unicast.getAddress(), 13, 15)) |
| } |
| |
| @Test |
| fun testConvertIpv6AddressToSolicitedNodeMulticast() { |
| val addr1 = NetworkStackUtils.ipv6AddressToSolicitedNodeMulticast(TEST_INET6ADDR_1) |
| assertSolicitedNodeMulticastAddress(addr1, TEST_INET6ADDR_1) |
| |
| val addr2 = NetworkStackUtils.ipv6AddressToSolicitedNodeMulticast(TEST_INET6ADDR_2) |
| assertSolicitedNodeMulticastAddress(addr2, TEST_INET6ADDR_2) |
| |
| val addr3 = NetworkStackUtils.ipv6AddressToSolicitedNodeMulticast(TEST_INET6ADDR_3) |
| assertSolicitedNodeMulticastAddress(addr3, TEST_INET6ADDR_3) |
| } |
| |
| @Test |
| fun testConvertMacAddressToEui64() { |
| // MAC address with universal/local bit set (the first byte: 0xBA) |
| var expected = byteArrayOf( |
| 0xB8.toByte(), 0x98.toByte(), 0x76.toByte(), 0xFF.toByte(), |
| 0xFE.toByte(), 0x54.toByte(), 0x32.toByte(), 0x10.toByte()) |
| val srcEui64 = NetworkStackUtils.macAddressToEui64(TEST_SRC_MAC) |
| assertArrayEquals(expected, srcEui64) |
| |
| // MAC address with universal/local bit unset (the first byte: 0x01). |
| expected = byteArrayOf( |
| 0x03.toByte(), 0x23.toByte(), 0x45.toByte(), 0xFF.toByte(), |
| 0xFE.toByte(), 0x67.toByte(), 0x89.toByte(), 0x0A.toByte()) |
| val targetEui64 = NetworkStackUtils.macAddressToEui64(TEST_TARGET_MAC) |
| assertArrayEquals(expected, targetEui64) |
| } |
| |
| @Test |
| fun testGenerateIpv6AddressFromEui64() { |
| val eui64 = NetworkStackUtils.macAddressToEui64(TEST_SRC_MAC) |
| var prefix = IpPrefix("2001:db8:1::/80") |
| // Don't accept the prefix length larger than 64. |
| assertNull(NetworkStackUtils.createInet6AddressFromEui64(prefix, eui64)) |
| |
| // prefix length equals to or less than 64 is acceptable. |
| prefix = IpPrefix("2001:db8:1::/48") |
| // IPv6 address string is formed by combining the IPv6 prefix("2001:db8:1::") and |
| // EUI64 converted from TEST_SRC_MAC, see above test for the output EUI64 example. |
| var expected = parseNumericAddress("2001:db8:1::b898:76ff:fe54:3210") as Inet6Address |
| assertEquals(expected, NetworkStackUtils.createInet6AddressFromEui64(prefix, eui64)) |
| |
| prefix = IpPrefix("2001:db8:1:2::/64") |
| expected = parseNumericAddress("2001:db8:1:2:b898:76ff:fe54:3210") as Inet6Address |
| assertEquals(expected, NetworkStackUtils.createInet6AddressFromEui64(prefix, eui64)) |
| } |
| |
| private fun assertSocketReadErrno(msg: String, fd: FileDescriptor, errno: Int) { |
| val received = ByteBuffer.allocate(TEST_MTU) |
| try { |
| val len = Os.read(fd, received) |
| fail(msg + ": " + toHexString(received, len)) |
| } catch (expected: ErrnoException) { |
| assertEquals(errno.toLong(), expected.errno.toLong()) |
| } |
| } |
| |
| private fun assertNextPacketOnSocket(fd: FileDescriptor, expectedPacket: ByteBuffer) { |
| val received = ByteBuffer.allocate(TEST_MTU) |
| val len = Os.read(fd, received) |
| assertEquals(toHexString(expectedPacket, expectedPacket.limit()), |
| toHexString(received, len)) |
| } |
| |
| private fun setMfBit(packet: ByteBuffer, set: Boolean) { |
| val offset = ETHER_HEADER_LEN + IPV4_FLAGS_OFFSET |
| var flagOff: Int = packet.getShort(offset).toInt() |
| if (set) { |
| flagOff = (flagOff or IPV4_FLAG_MF) and IPV4_FLAG_DF.inv() |
| } else { |
| flagOff = (flagOff or IPV4_FLAG_DF) and IPV4_FLAG_MF.inv() |
| } |
| packet.putShort(offset, flagOff.toShort()) |
| // Recalculate the checksum, which requires first clearing the checksum field. |
| val checksumOffset = ETHER_HEADER_LEN + IPV4_CHECKSUM_OFFSET |
| packet.putShort(checksumOffset, 0) |
| packet.putShort(checksumOffset, IpUtils.ipChecksum(packet, ETHER_HEADER_LEN)) |
| } |
| |
| private fun doTestDhcpResponseWithMfBitDropped(generic: Boolean) { |
| val ifindex = InterfaceParams.getByName(iface.interfaceName).index |
| val packetSock = Os.socket(AF_PACKET, SOCK_RAW or SOCK_NONBLOCK, /*protocol=*/0) |
| try { |
| if (generic) { |
| NetworkStackUtils.attachControlPacketFilter(packetSock) |
| } else { |
| NetworkStackUtils.attachDhcpFilter(packetSock) |
| } |
| val addr = SocketUtils.makePacketSocketAddress(OsConstants.ETH_P_IP, ifindex) |
| Os.bind(packetSock, addr) |
| val packet = DhcpPacket.buildNakPacket(DhcpPacket.ENCAP_L2, 42, |
| TEST_TARGET_IPV4_ADDR, /*relayIp=*/ IPV4_ADDR_ANY, TEST_TARGET_MAC.toByteArray(), |
| /*broadcast=*/ false, "NAK") |
| setMfBit(packet, true) |
| reader.sendResponse(packet) |
| |
| // Packet with MF bit set is not received. |
| assertSocketReadErrno("Packet with MF bit should have been dropped", |
| packetSock, OsConstants.EAGAIN) |
| |
| // Identical packet, except with MF bit cleared, should be received. |
| setMfBit(packet, false) |
| reader.sendResponse(packet) |
| assertNextPacketOnSocket(packetSock, packet) |
| } finally { |
| Os.close(packetSock) |
| } |
| } |
| |
| @Test |
| fun testDhcpResponseWithMfBitDropped() { |
| doTestDhcpResponseWithMfBitDropped(false) |
| } |
| |
| @Test |
| fun testGenericDhcpResponseWithMfBitDropped() { |
| doTestDhcpResponseWithMfBitDropped(true) |
| } |
| |
| @Test |
| fun testConvertIpv4AddressToEthernetMulticast() { |
| var mcastAddrs = listOf( |
| // ipv4 multicast address, multicast ethernet address |
| Pair( |
| InetAddress.getByName("224.0.0.1") as Inet4Address, |
| MacAddress.fromString("01:00:5e:00:00:01") |
| ), |
| Pair( |
| InetAddress.getByName("239.128.1.1") as Inet4Address, |
| MacAddress.fromString("01:00:5e:00:01:01") |
| ), |
| Pair( |
| InetAddress.getByName("239.255.255.255") as Inet4Address, |
| MacAddress.fromString("01:00:5e:7f:ff:ff") |
| ) |
| ) |
| |
| for ((addr, expectAddr) in mcastAddrs) { |
| val ether = NetworkStackUtils.ipv4MulticastToEthernetMulticast(addr) |
| assertEquals(expectAddr, ether) |
| } |
| } |
| } |
| |
| private fun ByteBuffer.readAsArray(): ByteArray { |
| val out = ByteArray(remaining()) |
| get(out) |
| return out |
| } |
| |
| private fun toHexString(b: ByteBuffer, len: Int): String { |
| return HexDump.toHexString(Arrays.copyOf(b.array(), len)) |
| } |
| |
| private fun <T : Any> Context.assertHasService(manager: KClass<T>) = getSystemService(manager.java) |
| ?: fail("Could not find service $manager") |
