Add basic netlink library code. (6193aa33) · Commits · e / os / android_frameworks_base

core/java/android/net/netlink/NetlinkConstants.java

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		/*
		* Copyright (C) 2015 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.netlink;

		import android.system.OsConstants;
		import com.android.internal.util.HexDump;

		import java.nio.ByteBuffer;


		/**
		* Various constants and static helper methods for netlink communications.
		*
		* Values taken from:
		*
		* <linux_src>/include/uapi/linux/netlink.h
		* <linux_src>/include/uapi/linux/rtnetlink.h
		*
		* @hide
		*/
		public class NetlinkConstants {
		private NetlinkConstants() {}

		public static final int NLA_ALIGNTO = 4;

		public static final int alignedLengthOf(short length) {
		final int intLength = (int) length & 0xffff;
		return alignedLengthOf(intLength);
		}

		public static final int alignedLengthOf(int length) {
		if (length <= 0) { return 0; }
		return (((length + NLA_ALIGNTO - 1) / NLA_ALIGNTO) * NLA_ALIGNTO);
		}

		public static String stringForAddressFamily(int family) {
		if (family == OsConstants.AF_INET) { return "AF_INET"; }
		if (family == OsConstants.AF_INET6) { return "AF_INET6"; }
		if (family == OsConstants.AF_NETLINK) { return "AF_NETLINK"; }
		return String.valueOf(family);
		}

		public static String hexify(byte[] bytes) {
		if (bytes == null) { return "(null)"; }
		return HexDump.toHexString(bytes);
		}

		public static String hexify(ByteBuffer buffer) {
		if (buffer == null) { return "(null)"; }
		return HexDump.toHexString(
		buffer.array(), buffer.position(), buffer.remaining());
		}

		// Known values for struct nlmsghdr nlm_type.
		public static final short NLMSG_NOOP = 1; // Nothing
		public static final short NLMSG_ERROR = 2; // Error
		public static final short NLMSG_DONE = 3; // End of a dump
		public static final short NLMSG_OVERRUN = 4; // Data lost
		public static final short NLMSG_MAX_RESERVED = 15; // Max reserved value

		public static final short RTM_NEWLINK = 16;
		public static final short RTM_DELLINK = 17;
		public static final short RTM_GETLINK = 18;
		public static final short RTM_SETLINK = 19;
		public static final short RTM_NEWADDR = 20;
		public static final short RTM_DELADDR = 21;
		public static final short RTM_GETADDR = 22;
		public static final short RTM_NEWROUTE = 24;
		public static final short RTM_DELROUTE = 25;
		public static final short RTM_GETROUTE = 26;
		public static final short RTM_NEWNEIGH = 28;
		public static final short RTM_DELNEIGH = 29;
		public static final short RTM_GETNEIGH = 30;
		public static final short RTM_NEWRULE = 32;
		public static final short RTM_DELRULE = 33;
		public static final short RTM_GETRULE = 34;
		public static final short RTM_NEWNDUSEROPT = 68;

		public static String stringForNlMsgType(short nlm_type) {
		switch (nlm_type) {
		case NLMSG_NOOP: return "NLMSG_NOOP";
		case NLMSG_ERROR: return "NLMSG_ERROR";
		case NLMSG_DONE: return "NLMSG_DONE";
		case NLMSG_OVERRUN: return "NLMSG_OVERRUN";
		case RTM_NEWLINK: return "RTM_NEWLINK";
		case RTM_DELLINK: return "RTM_DELLINK";
		case RTM_GETLINK: return "RTM_GETLINK";
		case RTM_SETLINK: return "RTM_SETLINK";
		case RTM_NEWADDR: return "RTM_NEWADDR";
		case RTM_DELADDR: return "RTM_DELADDR";
		case RTM_GETADDR: return "RTM_GETADDR";
		case RTM_NEWROUTE: return "RTM_NEWROUTE";
		case RTM_DELROUTE: return "RTM_DELROUTE";
		case RTM_GETROUTE: return "RTM_GETROUTE";
		case RTM_NEWNEIGH: return "RTM_NEWNEIGH";
		case RTM_DELNEIGH: return "RTM_DELNEIGH";
		case RTM_GETNEIGH: return "RTM_GETNEIGH";
		case RTM_NEWRULE: return "RTM_NEWRULE";
		case RTM_DELRULE: return "RTM_DELRULE";
		case RTM_GETRULE: return "RTM_GETRULE";
		case RTM_NEWNDUSEROPT: return "RTM_NEWNDUSEROPT";
		default:
		return "unknown RTM type: " + String.valueOf(nlm_type);
		}
		}
		}

core/java/android/net/netlink/NetlinkErrorMessage.java

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		/*
		* Copyright (C) 2015 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.netlink;

		import android.net.netlink.StructNlMsgHdr;
		import android.net.netlink.NetlinkMessage;
		import android.util.Log;

		import java.nio.ByteBuffer;


		/**
		* A NetlinkMessage subclass for netlink error messages.
		*
		* @hide
		*/
		public class NetlinkErrorMessage extends NetlinkMessage {

		public static NetlinkErrorMessage parse(StructNlMsgHdr header, ByteBuffer byteBuffer) {
		final NetlinkErrorMessage errorMsg = new NetlinkErrorMessage(header);

		errorMsg.mNlMsgErr = StructNlMsgErr.parse(byteBuffer);
		if (errorMsg.mNlMsgErr == null) {
		return null;
		}

		return errorMsg;
		}

		private StructNlMsgErr mNlMsgErr;

		NetlinkErrorMessage(StructNlMsgHdr header) {
		super(header);
		mNlMsgErr = null;
		}

		public StructNlMsgErr getNlMsgError() {
		return mNlMsgErr;
		}

		@Override
		public String toString() {
		return "NetlinkErrorMessage{ "
		+ "nlmsghdr{" + (mHeader == null ? "" : mHeader.toString()) + "}, "
		+ "nlmsgerr{" + (mNlMsgErr == null ? "" : mNlMsgErr.toString()) + "} "
		+ "}";
		}
		}

core/java/android/net/netlink/NetlinkMessage.java

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		/*
		* Copyright (C) 2015 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.netlink;

		import android.net.netlink.NetlinkConstants;
		import android.net.netlink.NetlinkErrorMessage;
		import android.net.netlink.RtNetlinkNeighborMessage;
		import android.net.netlink.StructNlAttr;
		import android.net.netlink.StructNlMsgHdr;
		import android.util.Log;

		import java.nio.ByteBuffer;


		/**
		* NetlinkMessage base class for other, more specific netlink message types.
		*
		* Classes that extend NetlinkMessage should:
		* - implement a public static parse(StructNlMsgHdr, ByteBuffer) method
		* - returning either null (parse errors) or a new object of the subclass
		* type (cast-able to NetlinkMessage)
		*
		* NetlinkMessage.parse() should be updated to know which nlmsg_type values
		* correspond with which message subclasses.
		*
		* @hide
		*/
		public class NetlinkMessage {
		private final static String TAG = "NetlinkMessage";

		public static NetlinkMessage parse(ByteBuffer byteBuffer) {
		final int startPosition = (byteBuffer != null) ? byteBuffer.position() : -1;
		final StructNlMsgHdr nlmsghdr = StructNlMsgHdr.parse(byteBuffer);
		if (nlmsghdr == null) {
		return null;
		}

		int payloadLength = NetlinkConstants.alignedLengthOf(nlmsghdr.nlmsg_len);
		payloadLength -= StructNlMsgHdr.STRUCT_SIZE;
		if (payloadLength < 0 \|\| payloadLength > byteBuffer.remaining()) {
		// Malformed message or runt buffer. Pretend the buffer was consumed.
		byteBuffer.position(byteBuffer.limit());
		return null;
		}

		switch (nlmsghdr.nlmsg_type) {
		//case NetlinkConstants.NLMSG_NOOP:
		case NetlinkConstants.NLMSG_ERROR:
		return (NetlinkMessage) NetlinkErrorMessage.parse(byteBuffer);
		case NetlinkConstants.NLMSG_DONE:
		byteBuffer.position(byteBuffer.position() + payloadLength);
		return new NetlinkMessage(nlmsghdr);
		//case NetlinkConstants.NLMSG_OVERRUN:
		case NetlinkConstants.RTM_NEWNEIGH:
		case NetlinkConstants.RTM_DELNEIGH:
		case NetlinkConstants.RTM_GETNEIGH:
		return (NetlinkMessage) RtNetlinkNeighborMessage.parse(nlmsghdr, byteBuffer);
		default:
		if (nlmsghdr.nlmsg_type <= NetlinkConstants.NLMSG_MAX_RESERVED) {
		// Netlink control message. Just parse the header for now,
		// pretending the whole message was consumed.
		byteBuffer.position(byteBuffer.position() + payloadLength);
		return new NetlinkMessage(nlmsghdr);
		}
		return null;
		}
		}

		protected StructNlMsgHdr mHeader;

		public NetlinkMessage(StructNlMsgHdr nlmsghdr) {
		mHeader = nlmsghdr;
		}

		public StructNlMsgHdr getHeader() {
		return mHeader;
		}

		@Override
		public String toString() {
		return "NetlinkMessage{" + (mHeader == null ? "" : mHeader.toString()) + "}";
		}
		}

core/java/android/net/netlink/NetlinkSocket.java

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		/*
		* Copyright (C) 2015 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.netlink;

		import android.system.ErrnoException;
		import android.system.NetlinkSocketAddress;
		import android.system.Os;
		import android.system.OsConstants;
		import android.system.StructTimeval;
		import android.util.Log;
		import libcore.io.IoUtils;
		import libcore.io.Libcore;

		import java.io.Closeable;
		import java.io.FileDescriptor;
		import java.io.InterruptedIOException;
		import java.net.SocketAddress;
		import java.net.SocketException;
		import java.nio.ByteBuffer;
		import java.nio.ByteOrder;


		/**
		* NetlinkSocket
		*
		* A small wrapper class to assist with AF_NETLINK socket operations.
		*
		* @hide
		*/
		public class NetlinkSocket implements Closeable {
		private static final String TAG = "NetlinkSocket";
		private static final int SOCKET_RECV_BUFSIZE = 64 * 1024;
		private static final int DEFAULT_RECV_BUFSIZE = 8 * 1024;

		final private FileDescriptor mDescriptor;
		private NetlinkSocketAddress mAddr;
		private long mLastRecvTimeoutMs;
		private long mLastSendTimeoutMs;

		public NetlinkSocket(int nlProto) throws ErrnoException {
		mDescriptor = Os.socket(
		OsConstants.AF_NETLINK, OsConstants.SOCK_DGRAM, nlProto);

		Libcore.os.setsockoptInt(
		mDescriptor, OsConstants.SOL_SOCKET,
		OsConstants.SO_RCVBUF, SOCKET_RECV_BUFSIZE);
		}

		public NetlinkSocketAddress getLocalAddress() throws ErrnoException {
		return (NetlinkSocketAddress) Os.getsockname(mDescriptor);
		}

		public void bind(NetlinkSocketAddress localAddr) throws ErrnoException, SocketException {
		Os.bind(mDescriptor, (SocketAddress)localAddr);
		}

		public void connectTo(NetlinkSocketAddress peerAddr)
		throws ErrnoException, SocketException {
		Os.connect(mDescriptor, (SocketAddress) peerAddr);
		}

		public void connectToKernel() throws ErrnoException, SocketException {
		connectTo(new NetlinkSocketAddress(0, 0));
		}

		/**
		* Wait indefinitely (or until underlying socket error) for a
		* netlink message of at most DEFAULT_RECV_BUFSIZE size.
		*/
		public ByteBuffer recvMessage()
		throws ErrnoException, InterruptedIOException {
		return recvMessage(DEFAULT_RECV_BUFSIZE, 0);
		}

		/**
		* Wait up to \|timeoutMs\| (or until underlying socket error) for a
		* netlink message of at most DEFAULT_RECV_BUFSIZE size.
		*/
		public ByteBuffer recvMessage(long timeoutMs) throws ErrnoException, InterruptedIOException {
		return recvMessage(DEFAULT_RECV_BUFSIZE, timeoutMs);
		}

		private void checkTimeout(long timeoutMs) {
		if (timeoutMs < 0) {
		throw new IllegalArgumentException("Negative timeouts not permitted");
		}
		}

		/**
		* Wait up to \|timeoutMs\| (or until underlying socket error) for a
		* netlink message of at most \|bufsize\| size.
		*
		* Multi-threaded calls with different timeouts will cause unexpected results.
		*/
		public ByteBuffer recvMessage(int bufsize, long timeoutMs)
		throws ErrnoException, IllegalArgumentException, InterruptedIOException {
		checkTimeout(timeoutMs);

		synchronized (mDescriptor) {
		if (mLastRecvTimeoutMs != timeoutMs) {
		Os.setsockoptTimeval(mDescriptor,
		OsConstants.SOL_SOCKET, OsConstants.SO_RCVTIMEO,
		StructTimeval.fromMillis(timeoutMs));
		mLastRecvTimeoutMs = timeoutMs;
		}
		}

		ByteBuffer byteBuffer = ByteBuffer.allocate(bufsize);
		int length = Os.read(mDescriptor, byteBuffer);
		if (length == bufsize) {
		Log.w(TAG, "maximum read");
		}
		byteBuffer.position(0);
		byteBuffer.limit(length);
		byteBuffer.order(ByteOrder.nativeOrder());
		return byteBuffer;
		}

		/**
		* Send a message to a peer to which this socket has previously connected.
		*
		* This blocks until completion or an error occurs.
		*/
		public boolean sendMessage(byte[] bytes, int offset, int count)
		throws ErrnoException, InterruptedIOException {
		return sendMessage(bytes, offset, count, 0);
		}

		/**
		* Send a message to a peer to which this socket has previously connected,
		* waiting at most \|timeoutMs\| milliseconds for the send to complete.
		*
		* Multi-threaded calls with different timeouts will cause unexpected results.
		*/
		public boolean sendMessage(byte[] bytes, int offset, int count, long timeoutMs)
		throws ErrnoException, IllegalArgumentException, InterruptedIOException {
		checkTimeout(timeoutMs);

		synchronized (mDescriptor) {
		if (mLastSendTimeoutMs != timeoutMs) {
		Os.setsockoptTimeval(mDescriptor,
		OsConstants.SOL_SOCKET, OsConstants.SO_SNDTIMEO,
		StructTimeval.fromMillis(timeoutMs));
		mLastSendTimeoutMs = timeoutMs;
		}
		}

		return (count == Os.write(mDescriptor, bytes, offset, count));
		}

		@Override
		public void close() {
		IoUtils.closeQuietly(mDescriptor);
		}
		}

core/java/android/net/netlink/RtNetlinkNeighborMessage.java

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		/*
		* Copyright (C) 2015 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.netlink;

		import android.net.netlink.StructNdaCacheInfo;
		import android.net.netlink.StructNdMsg;
		import android.net.netlink.StructNlAttr;
		import android.net.netlink.StructNlMsgHdr;
		import android.net.netlink.NetlinkMessage;
		import android.util.Log;

		import java.net.InetAddress;
		import java.nio.ByteBuffer;
		import java.nio.ByteOrder;


		/**
		* A NetlinkMessage subclass for netlink error messages.
		*
		* see also: <linux_src>/include/uapi/linux/neighbour.h
		*
		* @hide
		*/
		public class RtNetlinkNeighborMessage extends NetlinkMessage {
		public static final short NDA_UNSPEC = 0;
		public static final short NDA_DST = 1;
		public static final short NDA_LLADDR = 2;
		public static final short NDA_CACHEINFO = 3;
		public static final short NDA_PROBES = 4;
		public static final short NDA_VLAN = 5;
		public static final short NDA_PORT = 6;
		public static final short NDA_VNI = 7;
		public static final short NDA_IFINDEX = 8;
		public static final short NDA_MASTER = 9;

		private static StructNlAttr findNextAttrOfType(short attrType, ByteBuffer byteBuffer) {
		while (byteBuffer != null && byteBuffer.remaining() > 0) {
		final StructNlAttr nlAttr = StructNlAttr.peek(byteBuffer);
		if (nlAttr == null) {
		break;
		}
		if (nlAttr.nla_type == attrType) {
		return StructNlAttr.parse(byteBuffer);
		}
		if (byteBuffer.remaining() < nlAttr.getAlignedLength()) {
		break;
		}
		byteBuffer.position(byteBuffer.position() + nlAttr.getAlignedLength());
		}
		return null;
		}

		public static RtNetlinkNeighborMessage parse(StructNlMsgHdr header, ByteBuffer byteBuffer) {
		final RtNetlinkNeighborMessage neighMsg = new RtNetlinkNeighborMessage(header);

		neighMsg.mNdmsg = StructNdMsg.parse(byteBuffer);
		if (neighMsg.mNdmsg == null) {
		return null;
		}

		// Some of these are message-type dependent, and not always present.
		final int baseOffset = byteBuffer.position();
		StructNlAttr nlAttr = findNextAttrOfType(NDA_DST, byteBuffer);
		if (nlAttr != null) {
		neighMsg.mDestination = nlAttr.getValueAsInetAddress();
		}

		byteBuffer.position(baseOffset);
		nlAttr = findNextAttrOfType(NDA_LLADDR, byteBuffer);
		if (nlAttr != null) {
		neighMsg.mLinkLayerAddr = nlAttr.nla_value;
		}

		byteBuffer.position(baseOffset);
		nlAttr = findNextAttrOfType(NDA_PROBES, byteBuffer);
		if (nlAttr != null) {
		neighMsg.mNumProbes = nlAttr.getValueAsInt(0);
		}

		byteBuffer.position(baseOffset);
		nlAttr = findNextAttrOfType(NDA_CACHEINFO, byteBuffer);
		if (nlAttr != null) {
		neighMsg.mCacheInfo = StructNdaCacheInfo.parse(nlAttr.getValueAsByteBuffer());
		}

		final int kMinConsumed = StructNlMsgHdr.STRUCT_SIZE + StructNdMsg.STRUCT_SIZE;
		final int kAdditionalSpace = NetlinkConstants.alignedLengthOf(
		neighMsg.mHeader.nlmsg_len - kMinConsumed);
		if (byteBuffer.remaining() < kAdditionalSpace) {
		byteBuffer.position(byteBuffer.limit());
		} else {
		byteBuffer.position(baseOffset + kAdditionalSpace);
		}

		return neighMsg;
		}

		/**
		* A convenience method to create an RTM_GETNEIGH request message.
		*/
		public static byte[] newGetNeighborsRequest(int seqNo) {
		final int length = StructNlMsgHdr.STRUCT_SIZE + StructNdMsg.STRUCT_SIZE;
		final byte[] bytes = new byte[length];
		final ByteBuffer byteBuffer = ByteBuffer.wrap(bytes);
		byteBuffer.order(ByteOrder.nativeOrder());

		final StructNlMsgHdr nlmsghdr = new StructNlMsgHdr();
		nlmsghdr.nlmsg_len = length;
		nlmsghdr.nlmsg_type = NetlinkConstants.RTM_GETNEIGH;
		nlmsghdr.nlmsg_flags = StructNlMsgHdr.NLM_F_REQUEST\|StructNlMsgHdr.NLM_F_DUMP;
		nlmsghdr.nlmsg_seq = seqNo;
		nlmsghdr.pack(byteBuffer);

		final StructNdMsg ndmsg = new StructNdMsg();
		ndmsg.pack(byteBuffer);

		return bytes;
		}

		private StructNdMsg mNdmsg;
		private InetAddress mDestination;
		private byte[] mLinkLayerAddr;
		private int mNumProbes;
		private StructNdaCacheInfo mCacheInfo;

		private RtNetlinkNeighborMessage(StructNlMsgHdr header) {
		super(header);
		mNdmsg = null;
		mDestination = null;
		mLinkLayerAddr = null;
		mNumProbes = 0;
		mCacheInfo = null;
		}

		public StructNdMsg getNdHeader() {
		return mNdmsg;
		}

		public InetAddress getDestination() {
		return mDestination;
		}

		public byte[] getLinkLayerAddress() {
		return mLinkLayerAddr;
		}

		public int getProbes() {
		return mNumProbes;
		}

		public StructNdaCacheInfo getCacheInfo() {
		return mCacheInfo;
		}

		@Override
		public String toString() {
		final String ipLiteral = (mDestination == null) ? "" : mDestination.getHostAddress();
		return "RtNetlinkNeighborMessage{ "
		+ "nlmsghdr{" + (mHeader == null ? "" : mHeader.toString()) + "}, "
		+ "ndmsg{" + (mNdmsg == null ? "" : mNdmsg.toString()) + "}, "
		+ "destination{" + ipLiteral + "} "
		+ "linklayeraddr{" + NetlinkConstants.hexify(mLinkLayerAddr) + "} "
		+ "probes{" + mNumProbes + "} "
		+ "cacheinfo{" + (mCacheInfo == null ? "" : mCacheInfo.toString()) + "} "
		+ "}";
		}
		}