Merge "Implement IPv4 address conflict detection and DHCPDECLINE." (a0a8ed53) · Commits · e / os / android_packages_modules_NetworkStack

src/android/net/dhcp/DhcpClient.java

+391 −19

File changed.

Preview size limit exceeded, changes collapsed.

src/android/net/dhcp/DhcpDeclinePacket.java

+6 −2

Original line number	Diff line number	Diff line
		@@ -27,9 +27,11 @@ public class DhcpDeclinePacket extends DhcpPacket {
		* Generates a DECLINE packet with the specified parameters.
		*/
		DhcpDeclinePacket(int transId, short secs, Inet4Address clientIp, Inet4Address yourIp,
		Inet4Address nextIp, Inet4Address relayIp,
		byte[] clientMac) {
		Inet4Address nextIp, Inet4Address relayIp, byte[] clientMac,
		Inet4Address requestedIpAddress, Inet4Address serverIdentifier) {
		super(transId, secs, clientIp, yourIp, nextIp, relayIp, clientMac, false);
		mRequestedIp = requestedIpAddress;
		mServerIdentifier = serverIdentifier;
		}

		public String toString() {
		@@ -55,6 +57,8 @@ public class DhcpDeclinePacket extends DhcpPacket {
		void finishPacket(ByteBuffer buffer) {
		addTlv(buffer, DHCP_MESSAGE_TYPE, DHCP_MESSAGE_TYPE_DECLINE);
		addTlv(buffer, DHCP_CLIENT_IDENTIFIER, getClientId());
		addTlv(buffer, DHCP_REQUESTED_IP, mRequestedIp);
		addTlv(buffer, DHCP_SERVER_IDENTIFIER, mServerIdentifier);
		// RFC 2131 says we MUST NOT include our common client TLVs or the parameter request list.
		addTlvEnd(buffer);
		}

src/android/net/dhcp/DhcpPacket.java

+31 −17

Original line number	Diff line number	Diff line
		@@ -210,7 +210,8 @@ public abstract class DhcpPacket {
		* DHCP Optional Type: DHCP Requested IP Address
		*/
		protected static final byte DHCP_REQUESTED_IP = 50;
		protected Inet4Address mRequestedIp;
		@VisibleForTesting(otherwise = VisibleForTesting.PROTECTED)
		public Inet4Address mRequestedIp;

		/**
		* DHCP Optional Type: DHCP Lease Time
		@@ -236,7 +237,8 @@ public abstract class DhcpPacket {
		* DHCP Optional Type: DHCP Server Identifier
		*/
		protected static final byte DHCP_SERVER_IDENTIFIER = 54;
		protected Inet4Address mServerIdentifier;
		@VisibleForTesting(otherwise = VisibleForTesting.PROTECTED)
		public Inet4Address mServerIdentifier;

		/**
		* DHCP Optional Type: DHCP Parameter List
		@@ -1189,8 +1191,8 @@ public abstract class DhcpPacket {
		break;
		case DHCP_MESSAGE_TYPE_DECLINE:
		newPacket = new DhcpDeclinePacket(
		transactionId, secs, clientIp, yourIp, nextIp, relayIp,
		clientMac);
		transactionId, secs, clientIp, yourIp, nextIp, relayIp, clientMac, requestedIp,
		serverIdentifier);
		break;
		case DHCP_MESSAGE_TYPE_ACK:
		newPacket = new DhcpAckPacket(
		@@ -1417,4 +1419,16 @@ public abstract class DhcpPacket {
		ByteBuffer result = pkt.buildPacket(encap, DHCP_SERVER, DHCP_CLIENT);
		return result;
		}

		/**
		* Builds a DHCP-DECLINE packet from the required specified parameters.
		*/
		public static ByteBuffer buildDeclinePacket(int encap, int transactionId, byte[] clientMac,
		Inet4Address requestedIpAddress, Inet4Address serverIdentifier) {
		DhcpPacket pkt = new DhcpDeclinePacket(transactionId, (short) 0 /* secs */,
		INADDR_ANY /* clientIp /, INADDR_ANY / yourIp /, INADDR_ANY / nextIp */,
		INADDR_ANY /* relayIp */, clientMac, requestedIpAddress, serverIdentifier);
		ByteBuffer result = pkt.buildPacket(encap, DHCP_SERVER, DHCP_CLIENT);
		return result;
		}
		}

src/android/net/util/NetworkStackUtils.java

+15 −0

Original line number	Diff line number	Diff line
		@@ -121,6 +121,21 @@ public class NetworkStackUtils {
		*/
		public static final String DHCP_RAPID_COMMIT_ENABLED = "dhcp_rapid_commit_enabled";

		/**
		* Minimum module version at which to enable the DHCP INIT-REBOOT state.
		*/
		public static final String DHCP_INIT_REBOOT_VERSION = "dhcp_init_reboot_version";

		/**
		* Minimum module version at which to enable the DHCP Rapid Commit option.
		*/
		public static final String DHCP_RAPID_COMMIT_VERSION = "dhcp_rapid_commit_version";

		/**
		* Minimum module version at which to enable the IP address conflict detection feature.
		*/
		public static final String DHCP_IP_CONFLICT_DETECT_VERSION = "dhcp_ip_conflict_detect_version";

		static {
		System.loadLibrary("networkstackutilsjni");
		}

src/com/android/networkstack/arp/ArpPacket.java

0 → 100644

+171 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2019 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.networkstack.arp;

		import static android.system.OsConstants.ETH_P_ARP;
		import static android.system.OsConstants.ETH_P_IP;

		import static com.android.server.util.NetworkStackConstants.ARP_ETHER_IPV4_LEN;
		import static com.android.server.util.NetworkStackConstants.ARP_HWTYPE_ETHER;
		import static com.android.server.util.NetworkStackConstants.ARP_REPLY;
		import static com.android.server.util.NetworkStackConstants.ARP_REQUEST;
		import static com.android.server.util.NetworkStackConstants.ETHER_ADDR_LEN;
		import static com.android.server.util.NetworkStackConstants.IPV4_ADDR_LEN;

		import android.net.MacAddress;

		import com.android.internal.annotations.VisibleForTesting;

		import java.net.Inet4Address;
		import java.net.InetAddress;
		import java.net.UnknownHostException;
		import java.nio.BufferUnderflowException;
		import java.nio.ByteBuffer;

		/**
		* Defines basic data and operations needed to build and parse packets for the
		* ARP protocol.
		*
		* @hide
		*/
		public class ArpPacket {
		private static final String TAG = "ArpPacket";

		public final short opCode;
		public final Inet4Address senderIp;
		public final Inet4Address targetIp;
		public final MacAddress senderHwAddress;
		public final MacAddress targetHwAddress;

		ArpPacket(short opCode, MacAddress senderHwAddress, Inet4Address senderIp,
		MacAddress targetHwAddress, Inet4Address targetIp) {
		this.opCode = opCode;
		this.senderHwAddress = senderHwAddress;
		this.senderIp = senderIp;
		this.targetHwAddress = targetHwAddress;
		this.targetIp = targetIp;
		}

		/**
		* Build an ARP packet from the required specified parameters.
		*/
		@VisibleForTesting
		public static ByteBuffer buildArpPacket(final byte[] dstMac, final byte[] srcMac,
		final byte[] targetIp, final byte[] targetHwAddress, byte[] senderIp,
		final short opCode) {
		final ByteBuffer buf = ByteBuffer.allocate(ARP_ETHER_IPV4_LEN);

		// Ether header
		buf.put(dstMac);
		buf.put(srcMac);
		buf.putShort((short) ETH_P_ARP);

		// ARP header
		buf.putShort((short) ARP_HWTYPE_ETHER); // hrd
		buf.putShort((short) ETH_P_IP); // pro
		buf.put((byte) ETHER_ADDR_LEN); // hln
		buf.put((byte) IPV4_ADDR_LEN); // pln
		buf.putShort(opCode); // op
		buf.put(srcMac); // sha
		buf.put(senderIp); // spa
		buf.put(targetHwAddress); // tha
		buf.put(targetIp); // tpa
		buf.flip();
		return buf;
		}

		/**
		* Parse an ARP packet from an ByteBuffer object.
		*/
		@VisibleForTesting
		public static ArpPacket parseArpPacket(final byte[] recvbuf, final int length)
		throws ParseException {
		try {
		if (length < ARP_ETHER_IPV4_LEN \|\| recvbuf.length < length) {
		throw new ParseException("Invalid packet length: " + length);
		}

		final ByteBuffer buffer = ByteBuffer.wrap(recvbuf, 0, length);
		byte[] l2dst = new byte[ETHER_ADDR_LEN];
		byte[] l2src = new byte[ETHER_ADDR_LEN];
		buffer.get(l2dst);
		buffer.get(l2src);

		final short etherType = buffer.getShort();
		if (etherType != ETH_P_ARP) {
		throw new ParseException("Incorrect Ether Type: " + etherType);
		}

		final short hwType = buffer.getShort();
		if (hwType != ARP_HWTYPE_ETHER) {
		throw new ParseException("Incorrect HW Type: " + hwType);
		}

		final short protoType = buffer.getShort();
		if (protoType != ETH_P_IP) {
		throw new ParseException("Incorrect Protocol Type: " + protoType);
		}

		final byte hwAddrLength = buffer.get();
		if (hwAddrLength != ETHER_ADDR_LEN) {
		throw new ParseException("Incorrect HW address length: " + hwAddrLength);
		}

		final byte ipAddrLength = buffer.get();
		if (ipAddrLength != IPV4_ADDR_LEN) {
		throw new ParseException("Incorrect Protocol address length: " + ipAddrLength);
		}

		final short opCode = buffer.getShort();
		if (opCode != ARP_REQUEST && opCode != ARP_REPLY) {
		throw new ParseException("Incorrect opCode: " + opCode);
		}

		byte[] senderHwAddress = new byte[ETHER_ADDR_LEN];
		byte[] senderIp = new byte[IPV4_ADDR_LEN];
		buffer.get(senderHwAddress);
		buffer.get(senderIp);

		byte[] targetHwAddress = new byte[ETHER_ADDR_LEN];
		byte[] targetIp = new byte[IPV4_ADDR_LEN];
		buffer.get(targetHwAddress);
		buffer.get(targetIp);

		return new ArpPacket(opCode, MacAddress.fromBytes(senderHwAddress),
		(Inet4Address) InetAddress.getByAddress(senderIp),
		MacAddress.fromBytes(targetHwAddress),
		(Inet4Address) InetAddress.getByAddress(targetIp));
		} catch (IndexOutOfBoundsException e) {
		throw new ParseException("Invalid index when wrapping a byte array into a buffer");
		} catch (BufferUnderflowException e) {
		throw new ParseException("Invalid buffer position");
		} catch (IllegalArgumentException e) {
		throw new ParseException("Invalid MAC address representation");
		} catch (UnknownHostException e) {
		throw new ParseException("Invalid IP address of Host");
		}
		}

		/**
		* Thrown when parsing ARP packet failed.
		*/
		public static class ParseException extends Exception {
		ParseException(String message) {
		super(message);
		}
		}
		}