Add DHCP error event class and record DHCP errors. (62418743) · Commits · e / os / android_frameworks_base

core/java/android/net/metrics/DhcpErrorEvent.java

0 → 100644

+93 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2016 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.metrics;

		import android.os.Parcel;
		import android.os.Parcelable;

		/**
		* {@hide} Event class used to record error events when parsing DHCP response packets.
		*/
		public class DhcpErrorEvent extends IpConnectivityEvent implements Parcelable {
		public static final String TAG = "DhcpErrorEvent";

		public static final int L2_ERROR = 1;
		public static final int L3_ERROR = 2;
		public static final int L4_ERROR = 3;
		public static final int DHCP_ERROR = 4;
		public static final int MISC_ERROR = 5;

		public static final int L2_TOO_SHORT = makeErrorCode(L2_ERROR, 1);
		public static final int L2_WRONG_ETH_TYPE = makeErrorCode(L2_ERROR, 2);

		public static final int L3_TOO_SHORT = makeErrorCode(L3_ERROR, 1);
		public static final int L3_NOT_IPV4 = makeErrorCode(L3_ERROR, 2);
		public static final int L3_INVALID_IP = makeErrorCode(L3_ERROR, 3);

		public static final int L4_NOT_UDP = makeErrorCode(L4_ERROR, 1);
		public static final int L4_WRONG_PORT = makeErrorCode(L4_ERROR, 2);

		public static final int BOOTP_TOO_SHORT = makeErrorCode(DHCP_ERROR, 1);
		public static final int DHCP_BAD_MAGIC_COOKIE = makeErrorCode(DHCP_ERROR, 2);
		public static final int DHCP_INVALID_OPTION_LENGTH = makeErrorCode(DHCP_ERROR, 3);
		public static final int DHCP_NO_MSG_TYPE = makeErrorCode(DHCP_ERROR, 4);
		public static final int DHCP_UNKNOWN_MSG_TYPE = makeErrorCode(DHCP_ERROR, 5);

		public static final int BUFFER_UNDERFLOW = makeErrorCode(MISC_ERROR, 1);

		// error code byte format (MSB to LSB):
		// byte 0: error type
		// byte 1: error subtype
		// byte 2: unused
		// byte 3: optional code
		public final int errorCode;

		private DhcpErrorEvent(int errorCode) {
		this.errorCode = errorCode;
		}

		private DhcpErrorEvent(Parcel in) {
		this.errorCode = in.readInt();
		}

		public void writeToParcel(Parcel out, int flags) {
		out.writeInt(errorCode);
		}

		public static final Parcelable.Creator<DhcpErrorEvent> CREATOR
		= new Parcelable.Creator<DhcpErrorEvent>() {
		public DhcpErrorEvent createFromParcel(Parcel in) {
		return new DhcpErrorEvent(in);
		}

		public DhcpErrorEvent[] newArray(int size) {
		return new DhcpErrorEvent[size];
		}
		};

		public static void logEvent(int errorCode) {
		IpConnectivityEvent.logEvent(IPCE_DHCP_PARSE_ERROR, new DhcpErrorEvent(errorCode));
		}

		public static void logEvent(int errorCode, int option) {
		logEvent((0xFFFF0000 & errorCode) \| (0xFF & option));
		}

		private static int makeErrorCode(int type, int subtype) {
		return (type << 24) \| ((0xFF & subtype) << 16);
		}
		}

services/net/java/android/net/dhcp/DhcpPacket.java

+18 −3

Original line number	Diff line number	Diff line
		@@ -3,6 +3,7 @@ package android.net.dhcp;
		import android.net.DhcpResults;
		import android.net.LinkAddress;
		import android.net.NetworkUtils;
		import android.net.metrics.DhcpErrorEvent;
		import android.os.Build;
		import android.os.SystemProperties;
		import android.system.OsConstants;
		@@ -765,6 +766,7 @@ abstract class DhcpPacket {
		// check to see if we need to parse L2, IP, and UDP encaps
		if (pktType == ENCAP_L2) {
		if (packet.remaining() < MIN_PACKET_LENGTH_L2) {
		DhcpErrorEvent.logEvent(DhcpErrorEvent.L2_TOO_SHORT);
		throw new ParseException("L2 packet too short, %d < %d",
		packet.remaining(), MIN_PACKET_LENGTH_L2);
		}
		@@ -777,13 +779,16 @@ abstract class DhcpPacket {

		short l2type = packet.getShort();

		if (l2type != OsConstants.ETH_P_IP)
		if (l2type != OsConstants.ETH_P_IP) {
		DhcpErrorEvent.logEvent(DhcpErrorEvent.L2_WRONG_ETH_TYPE);
		throw new ParseException("Unexpected L2 type 0x%04x, expected 0x%04x",
		l2type, OsConstants.ETH_P_IP);
		}
		}

		if (pktType <= ENCAP_L3) {
		if (packet.remaining() < MIN_PACKET_LENGTH_L3) {
		DhcpErrorEvent.logEvent(DhcpErrorEvent.L3_TOO_SHORT);
		throw new ParseException("L3 packet too short, %d < %d",
		packet.remaining(), MIN_PACKET_LENGTH_L3);
		}
		@@ -791,6 +796,7 @@ abstract class DhcpPacket {
		byte ipTypeAndLength = packet.get();
		int ipVersion = (ipTypeAndLength & 0xf0) >> 4;
		if (ipVersion != 4) {
		DhcpErrorEvent.logEvent(DhcpErrorEvent.L3_NOT_IPV4);
		throw new ParseException("Invalid IP version %d", ipVersion);
		}

		@@ -808,6 +814,7 @@ abstract class DhcpPacket {
		ipDst = readIpAddress(packet);

		if (ipProto != IP_TYPE_UDP) {
		DhcpErrorEvent.logEvent(DhcpErrorEvent.L4_NOT_UDP);
		throw new ParseException("Protocol not UDP: %d", ipProto);
		}

		@@ -834,12 +841,14 @@ abstract class DhcpPacket {
		// socket to drop packets that don't have the right source ports. However, it's
		// possible that a packet arrives between when the socket is bound and when the
		// filter is set. http://b/26696823 .
		DhcpErrorEvent.logEvent(DhcpErrorEvent.L4_WRONG_PORT);
		throw new ParseException("Unexpected UDP ports %d->%d", udpSrcPort, udpDstPort);
		}
		}

		// We need to check the length even for ENCAP_L3 because the IPv4 header is variable-length.
		if (pktType > ENCAP_BOOTP \|\| packet.remaining() < MIN_PACKET_LENGTH_BOOTP) {
		DhcpErrorEvent.logEvent(DhcpErrorEvent.BOOTP_TOO_SHORT);
		throw new ParseException("Invalid type or BOOTP packet too short, %d < %d",
		packet.remaining(), MIN_PACKET_LENGTH_BOOTP);
		}
		@@ -864,6 +873,7 @@ abstract class DhcpPacket {
		packet.get(ipv4addr);
		relayIp = (Inet4Address) Inet4Address.getByAddress(ipv4addr);
		} catch (UnknownHostException ex) {
		DhcpErrorEvent.logEvent(DhcpErrorEvent.L3_INVALID_IP);
		throw new ParseException("Invalid IPv4 address: %s", Arrays.toString(ipv4addr));
		}

		@@ -888,6 +898,7 @@ abstract class DhcpPacket {
		int dhcpMagicCookie = packet.getInt();

		if (dhcpMagicCookie != DHCP_MAGIC_COOKIE) {
		DhcpErrorEvent.logEvent(DhcpErrorEvent.DHCP_BAD_MAGIC_COOKIE);
		throw new ParseException("Bad magic cookie 0x%08x, should be 0x%08x", dhcpMagicCookie,
		DHCP_MAGIC_COOKIE);
		}
		@@ -896,9 +907,8 @@ abstract class DhcpPacket {
		boolean notFinishedOptions = true;

		while ((packet.position() < packet.limit()) && notFinishedOptions) {
		final byte optionType = packet.get(); // cannot underflow because position < limit
		try {
		byte optionType = packet.get();

		if (optionType == DHCP_OPTION_END) {
		notFinishedOptions = false;
		} else if (optionType == DHCP_OPTION_PAD) {
		@@ -999,11 +1009,14 @@ abstract class DhcpPacket {
		}

		if (expectedLen != optionLen) {
		DhcpErrorEvent.logEvent(
		DhcpErrorEvent.DHCP_INVALID_OPTION_LENGTH, optionType);
		throw new ParseException("Invalid length %d for option %d, expected %d",
		optionLen, optionType, expectedLen);
		}
		}
		} catch (BufferUnderflowException e) {
		DhcpErrorEvent.logEvent(DhcpErrorEvent.BUFFER_UNDERFLOW, optionType);
		throw new ParseException("BufferUnderflowException");
		}
		}
		@@ -1012,6 +1025,7 @@ abstract class DhcpPacket {

		switch(dhcpType) {
		case (byte) 0xFF:
		DhcpErrorEvent.logEvent(DhcpErrorEvent.DHCP_NO_MSG_TYPE);
		throw new ParseException("No DHCP message type option");
		case DHCP_MESSAGE_TYPE_DISCOVER:
		newPacket = new DhcpDiscoverPacket(
		@@ -1045,6 +1059,7 @@ abstract class DhcpPacket {
		clientMac);
		break;
		default:
		DhcpErrorEvent.logEvent(DhcpErrorEvent.DHCP_UNKNOWN_MSG_TYPE);
		throw new ParseException("Unimplemented DHCP type %d", dhcpType);
		}