Create RouterAdvertisementResponder
This is useful for tests that need a provisioned tap interface.
Test: TH
Change-Id: I9a2eb3d8697bbcbfdb65563da609534b929a0715
diff --git a/staticlibs/testutils/devicetests/com/android/testutils/RouterAdvertisementResponder.java b/staticlibs/testutils/devicetests/com/android/testutils/RouterAdvertisementResponder.java
new file mode 100644
index 0000000..4ad93d8
--- /dev/null
+++ b/staticlibs/testutils/devicetests/com/android/testutils/RouterAdvertisementResponder.java
@@ -0,0 +1,123 @@
+/*
+ * Copyright (C) 2022 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 com.android.testutils;
+
+import static android.system.OsConstants.IPPROTO_ICMPV6;
+
+import static com.android.net.module.util.NetworkStackConstants.ETHER_ADDR_LEN;
+import static com.android.net.module.util.NetworkStackConstants.ETHER_SRC_ADDR_OFFSET;
+import static com.android.net.module.util.NetworkStackConstants.ETHER_TYPE_IPV6;
+import static com.android.net.module.util.NetworkStackConstants.ICMPV6_ROUTER_SOLICITATION;
+import static com.android.net.module.util.NetworkStackConstants.IPV6_ADDR_ALL_NODES_MULTICAST;
+import static com.android.net.module.util.NetworkStackConstants.IPV6_ADDR_ALL_ROUTERS_MULTICAST;
+import static com.android.net.module.util.NetworkStackConstants.PIO_FLAG_AUTONOMOUS;
+import static com.android.net.module.util.NetworkStackConstants.PIO_FLAG_ON_LINK;
+
+import android.net.InetAddresses;
+import android.net.IpPrefix;
+import android.net.LinkAddress;
+import android.net.MacAddress;
+import android.util.Pair;
+
+import com.android.net.module.util.Ipv6Utils;
+import com.android.net.module.util.Struct;
+import com.android.net.module.util.structs.EthernetHeader;
+import com.android.net.module.util.structs.Icmpv6Header;
+import com.android.net.module.util.structs.Ipv6Header;
+import com.android.net.module.util.structs.PrefixInformationOption;
+import com.android.net.module.util.structs.RdnssOption;
+
+import java.io.IOException;
+import java.net.Inet6Address;
+import java.nio.ByteBuffer;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+/**
+ * RA responder class useful for tests that require a provisioned interface.
+ */
+public class RouterAdvertisementResponder extends PacketResponder {
+ private static final String TAG = "RouterAdvertisementResponder";
+ private static final LinkAddress SLAAC_PREFIX = new LinkAddress("2001:db8::/64");
+ private static final Inet6Address DNS_SERVER =
+ (Inet6Address) InetAddresses.parseNumericAddress("2001:4860:4860::64");
+ private final TapPacketReader mPacketReader;
+ private final List<Pair<MacAddress, Inet6Address>> mRouterList = new ArrayList<>();
+
+ public RouterAdvertisementResponder(TapPacketReader packetReader) {
+ super(packetReader, RouterAdvertisementResponder::isRouterSolicitation, TAG);
+ mPacketReader = packetReader;
+ }
+
+ private static boolean isRouterSolicitation(byte[] packet) {
+ final ByteBuffer buffer = ByteBuffer.wrap(packet);
+ final EthernetHeader ethHeader = Struct.parse(EthernetHeader.class, buffer);
+ if (ethHeader.etherType != ETHER_TYPE_IPV6) {
+ return false;
+ }
+ final Ipv6Header ipv6Header = Struct.parse(Ipv6Header.class, buffer);
+ if (ipv6Header.nextHeader != IPPROTO_ICMPV6
+ || !ipv6Header.dstIp.equals(IPV6_ADDR_ALL_ROUTERS_MULTICAST)) {
+ return false;
+ }
+ final Icmpv6Header icmpv6Header = Struct.parse(Icmpv6Header.class, buffer);
+ return icmpv6Header.type == ICMPV6_ROUTER_SOLICITATION;
+ }
+
+ /**
+ * Adds a new router to be advertised.
+ * @param mac the mac address of the router.
+ * @param ip the link-local address of the router.
+ */
+ public void addRouterEntry(MacAddress mac, Inet6Address ip) {
+ mRouterList.add(new Pair<>(mac, ip));
+ }
+
+ private ByteBuffer buildPrefixOption() {
+ return PrefixInformationOption.build(
+ new IpPrefix(SLAAC_PREFIX.getAddress(), SLAAC_PREFIX.getPrefixLength()),
+ (byte) (PIO_FLAG_ON_LINK | PIO_FLAG_AUTONOMOUS), 3600/*valid lifetime*/,
+ 3600/*preferred lifetime*/);
+ }
+
+ private ByteBuffer buildRdnssOption() {
+ return RdnssOption.build(3600/*lifetime, must be at least 120*/, DNS_SERVER);
+ }
+
+ private ByteBuffer buildRaPacket(MacAddress srcMac, MacAddress dstMac, Inet6Address srcIp) {
+ return Ipv6Utils.buildRaPacket(srcMac, dstMac, srcIp, IPV6_ADDR_ALL_NODES_MULTICAST,
+ (byte) 0 /*M=0, O=0*/, 3600 /*lifetime*/, 0 /*reachableTime, unspecified*/,
+ 0/*retransTimer, unspecified*/, buildPrefixOption(), buildRdnssOption());
+ }
+
+ @Override
+ protected void replyToPacket(byte[] packet, TapPacketReader reader) {
+ final MacAddress srcMac = MacAddress.fromBytes(
+ Arrays.copyOfRange(packet, ETHER_SRC_ADDR_OFFSET,
+ ETHER_SRC_ADDR_OFFSET + ETHER_ADDR_LEN));
+
+ for (Pair<MacAddress, Inet6Address> it : mRouterList) {
+ final ByteBuffer raResponse = buildRaPacket(it.first, srcMac, it.second);
+ try {
+ reader.sendResponse(raResponse);
+ } catch (IOException e) {
+ throw new RuntimeException("Failed to send RA");
+ }
+ }
+ }
+}