Snap for 8090552 from 340ef7f3cdb7c57cc43ef35e83ec2755e13d512a to tm-release

Change-Id: I8f6ab1ea8769b6e36d38ee43aba108c00ee07caf

1 files changed, 809 insertions, 0 deletions

diff --git a/framework/java/android/bluetooth/BluetoothSocket.java b/framework/java/android/bluetooth/BluetoothSocket.java
new file mode 100644
index 0000000000..db5b75148e
--- /dev/null
+++ b/framework/java/android/bluetooth/BluetoothSocket.java
@@ -0,0 +1,809 @@
+/*
+ * Copyright (C) 2012 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.bluetooth;
+
+import android.annotation.RequiresNoPermission;
+import android.annotation.RequiresPermission;
+import android.bluetooth.annotations.RequiresBluetoothConnectPermission;
+import android.compat.annotation.UnsupportedAppUsage;
+import android.net.LocalSocket;
+import android.os.Build;
+import android.os.ParcelFileDescriptor;
+import android.os.ParcelUuid;
+import android.os.RemoteException;
+import android.util.Log;
+
+import java.io.Closeable;
+import java.io.FileDescriptor;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
+import java.util.Arrays;
+import java.util.Locale;
+import java.util.UUID;
+
+/**
+ * A connected or connecting Bluetooth socket.
+ *
+ * <p>The interface for Bluetooth Sockets is similar to that of TCP sockets:
+ * {@link java.net.Socket} and {@link java.net.ServerSocket}. On the server
+ * side, use a {@link BluetoothServerSocket} to create a listening server
+ * socket. When a connection is accepted by the {@link BluetoothServerSocket},
+ * it will return a new {@link BluetoothSocket} to manage the connection.
+ * On the client side, use a single {@link BluetoothSocket} to both initiate
+ * an outgoing connection and to manage the connection.
+ *
+ * <p>The most common type of Bluetooth socket is RFCOMM, which is the type
+ * supported by the Android APIs. RFCOMM is a connection-oriented, streaming
+ * transport over Bluetooth. It is also known as the Serial Port Profile (SPP).
+ *
+ * <p>To create a {@link BluetoothSocket} for connecting to a known device, use
+ * {@link BluetoothDevice#createRfcommSocketToServiceRecord
+ * BluetoothDevice.createRfcommSocketToServiceRecord()}.
+ * Then call {@link #connect()} to attempt a connection to the remote device.
+ * This call will block until a connection is established or the connection
+ * fails.
+ *
+ * <p>To create a {@link BluetoothSocket} as a server (or "host"), see the
+ * {@link BluetoothServerSocket} documentation.
+ *
+ * <p>Once the socket is connected, whether initiated as a client or accepted
+ * as a server, open the IO streams by calling {@link #getInputStream} and
+ * {@link #getOutputStream} in order to retrieve {@link java.io.InputStream}
+ * and {@link java.io.OutputStream} objects, respectively, which are
+ * automatically connected to the socket.
+ *
+ * <p>{@link BluetoothSocket} is thread
+ * safe. In particular, {@link #close} will always immediately abort ongoing
+ * operations and close the socket.
+ *
+ * <div class="special reference">
+ * <h3>Developer Guides</h3>
+ * <p>For more information about using Bluetooth, read the
+ * <a href="{@docRoot}guide/topics/connectivity/bluetooth.html">Bluetooth</a> developer guide.</p>
+ * </div>
+ *
+ * {@see BluetoothServerSocket}
+ * {@see java.io.InputStream}
+ * {@see java.io.OutputStream}
+ */
+public final class BluetoothSocket implements Closeable {
+    private static final String TAG = "BluetoothSocket";
+    private static final boolean DBG = Log.isLoggable(TAG, Log.DEBUG);
+    private static final boolean VDBG = Log.isLoggable(TAG, Log.VERBOSE);
+
+    /** @hide */
+    public static final int MAX_RFCOMM_CHANNEL = 30;
+    /*package*/ static final int MAX_L2CAP_PACKAGE_SIZE = 0xFFFF;
+
+    /** RFCOMM socket */
+    public static final int TYPE_RFCOMM = 1;
+
+    /** SCO socket */
+    public static final int TYPE_SCO = 2;
+
+    /** L2CAP socket */
+    public static final int TYPE_L2CAP = 3;
+
+    /** L2CAP socket on BR/EDR transport
+     * @hide
+     */
+    public static final int TYPE_L2CAP_BREDR = TYPE_L2CAP;
+
+    /** L2CAP socket on LE transport
+     * @hide
+     */
+    public static final int TYPE_L2CAP_LE = 4;
+
+    /*package*/ static final int EBADFD = 77;
+    @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553)
+    /*package*/ static final int EADDRINUSE = 98;
+
+    /*package*/ static final int SEC_FLAG_ENCRYPT = 1;
+    /*package*/ static final int SEC_FLAG_AUTH = 1 << 1;
+    /*package*/ static final int BTSOCK_FLAG_NO_SDP = 1 << 2;
+    /*package*/ static final int SEC_FLAG_AUTH_MITM = 1 << 3;
+    /*package*/ static final int SEC_FLAG_AUTH_16_DIGIT = 1 << 4;
+
+    private final int mType;  /* one of TYPE_RFCOMM etc */
+    private BluetoothDevice mDevice;    /* remote device */
+    private String mAddress;    /* remote address */
+    private final boolean mAuth;
+    private final boolean mEncrypt;
+    private final BluetoothInputStream mInputStream;
+    private final BluetoothOutputStream mOutputStream;
+    private final ParcelUuid mUuid;
+    /** when true no SPP SDP record will be created */
+    private boolean mExcludeSdp = false;
+    /** when true Person-in-the-middle protection will be enabled */
+    private boolean mAuthMitm = false;
+    /** Minimum 16 digit pin for sec mode 2 connections */
+    private boolean mMin16DigitPin = false;
+    @UnsupportedAppUsage(publicAlternatives = "Use {@link BluetoothSocket} public API instead.")
+    private ParcelFileDescriptor mPfd;
+    @UnsupportedAppUsage
+    private LocalSocket mSocket;
+    private InputStream mSocketIS;
+    private OutputStream mSocketOS;
+    @UnsupportedAppUsage
+    private int mPort;  /* RFCOMM channel or L2CAP psm */
+    private int mFd;
+    private String mServiceName;
+    private static final int PROXY_CONNECTION_TIMEOUT = 5000;
+
+    private static final int SOCK_SIGNAL_SIZE = 20;
+
+    private ByteBuffer mL2capBuffer = null;
+    private int mMaxTxPacketSize = 0; // The l2cap maximum packet size supported by the peer.
+    private int mMaxRxPacketSize = 0; // The l2cap maximum packet size that can be received.
+
+    private enum SocketState {
+        INIT,
+        CONNECTED,
+        LISTENING,
+        CLOSED,
+    }
+
+    /** prevents all native calls after destroyNative() */
+    private volatile SocketState mSocketState;
+
+    /** protects mSocketState */
+    //private final ReentrantReadWriteLock mLock;
+
+    /**
+     * Construct a BluetoothSocket.
+     *
+     * @param type type of socket
+     * @param fd fd to use for connected socket, or -1 for a new socket
+     * @param auth require the remote device to be authenticated
+     * @param encrypt require the connection to be encrypted
+     * @param device remote device that this socket can connect to
+     * @param port remote port
+     * @param uuid SDP uuid
+     * @throws IOException On error, for example Bluetooth not available, or insufficient
+     * privileges
+     */
+    /*package*/ BluetoothSocket(int type, int fd, boolean auth, boolean encrypt,
+            BluetoothDevice device, int port, ParcelUuid uuid) throws IOException {
+        this(type, fd, auth, encrypt, device, port, uuid, false, false);
+    }
+
+    /**
+     * Construct a BluetoothSocket.
+     *
+     * @param type type of socket
+     * @param fd fd to use for connected socket, or -1 for a new socket
+     * @param auth require the remote device to be authenticated
+     * @param encrypt require the connection to be encrypted
+     * @param device remote device that this socket can connect to
+     * @param port remote port
+     * @param uuid SDP uuid
+     * @param mitm enforce person-in-the-middle protection.
+     * @param min16DigitPin enforce a minimum length of 16 digits for a sec mode 2 connection
+     * @throws IOException On error, for example Bluetooth not available, or insufficient
+     * privileges
+     */
+    /*package*/ BluetoothSocket(int type, int fd, boolean auth, boolean encrypt,
+            BluetoothDevice device, int port, ParcelUuid uuid, boolean mitm, boolean min16DigitPin)
+            throws IOException {
+        if (VDBG) Log.d(TAG, "Creating new BluetoothSocket of type: " + type);
+        if (type == BluetoothSocket.TYPE_RFCOMM && uuid == null && fd == -1
+                && port != BluetoothAdapter.SOCKET_CHANNEL_AUTO_STATIC_NO_SDP) {
+            if (port < 1 || port > MAX_RFCOMM_CHANNEL) {
+                throw new IOException("Invalid RFCOMM channel: " + port);
+            }
+        }
+        if (uuid != null) {
+            mUuid = uuid;
+        } else {
+            mUuid = new ParcelUuid(new UUID(0, 0));
+        }
+        mType = type;
+        mAuth = auth;
+        mAuthMitm = mitm;
+        mMin16DigitPin = min16DigitPin;
+        mEncrypt = encrypt;
+        mDevice = device;
+        mPort = port;
+        mFd = fd;
+
+        mSocketState = SocketState.INIT;
+
+        if (device == null) {
+            // Server socket
+            mAddress = BluetoothAdapter.getDefaultAdapter().getAddress();
+        } else {
+            // Remote socket
+            mAddress = device.getAddress();
+        }
+        mInputStream = new BluetoothInputStream(this);
+        mOutputStream = new BluetoothOutputStream(this);
+    }
+
+    private BluetoothSocket(BluetoothSocket s) {
+        if (VDBG) Log.d(TAG, "Creating new Private BluetoothSocket of type: " + s.mType);
+        mUuid = s.mUuid;
+        mType = s.mType;
+        mAuth = s.mAuth;
+        mEncrypt = s.mEncrypt;
+        mPort = s.mPort;
+        mInputStream = new BluetoothInputStream(this);
+        mOutputStream = new BluetoothOutputStream(this);
+        mMaxRxPacketSize = s.mMaxRxPacketSize;
+        mMaxTxPacketSize = s.mMaxTxPacketSize;
+
+        mServiceName = s.mServiceName;
+        mExcludeSdp = s.mExcludeSdp;
+        mAuthMitm = s.mAuthMitm;
+        mMin16DigitPin = s.mMin16DigitPin;
+    }
+
+    private BluetoothSocket acceptSocket(String remoteAddr) throws IOException {
+        BluetoothSocket as = new BluetoothSocket(this);
+        as.mSocketState = SocketState.CONNECTED;
+        FileDescriptor[] fds = mSocket.getAncillaryFileDescriptors();
+        if (DBG) Log.d(TAG, "socket fd passed by stack fds: " + Arrays.toString(fds));
+        if (fds == null || fds.length != 1) {
+            Log.e(TAG, "socket fd passed from stack failed, fds: " + Arrays.toString(fds));
+            as.close();
+            throw new IOException("bt socket acept failed");
+        }
+
+        as.mPfd = ParcelFileDescriptor.dup(fds[0]);
+        as.mSocket = LocalSocket.createConnectedLocalSocket(fds[0]);
+        as.mSocketIS = as.mSocket.getInputStream();
+        as.mSocketOS = as.mSocket.getOutputStream();
+        as.mAddress = remoteAddr;
+        as.mDevice = BluetoothAdapter.getDefaultAdapter().getRemoteDevice(remoteAddr);
+        return as;
+    }
+
+    /**
+     * Construct a BluetoothSocket from address. Used by native code.
+     *
+     * @param type type of socket
+     * @param fd fd to use for connected socket, or -1 for a new socket
+     * @param auth require the remote device to be authenticated
+     * @param encrypt require the connection to be encrypted
+     * @param address remote device that this socket can connect to
+     * @param port remote port
+     * @throws IOException On error, for example Bluetooth not available, or insufficient
+     * privileges
+     */
+    private BluetoothSocket(int type, int fd, boolean auth, boolean encrypt, String address,
+            int port) throws IOException {
+        this(type, fd, auth, encrypt, new BluetoothDevice(address), port, null, false, false);
+    }
+
+    /** @hide */
+    @Override
+    protected void finalize() throws Throwable {
+        try {
+            close();
+        } finally {
+            super.finalize();
+        }
+    }
+
+    private int getSecurityFlags() {
+        int flags = 0;
+        if (mAuth) {
+            flags |= SEC_FLAG_AUTH;
+        }
+        if (mEncrypt) {
+            flags |= SEC_FLAG_ENCRYPT;
+        }
+        if (mExcludeSdp) {
+            flags |= BTSOCK_FLAG_NO_SDP;
+        }
+        if (mAuthMitm) {
+            flags |= SEC_FLAG_AUTH_MITM;
+        }
+        if (mMin16DigitPin) {
+            flags |= SEC_FLAG_AUTH_16_DIGIT;
+        }
+        return flags;
+    }
+
+    /**
+     * Get the remote device this socket is connecting, or connected, to.
+     *
+     * @return remote device
+     */
+    @RequiresNoPermission
+    public BluetoothDevice getRemoteDevice() {
+        return mDevice;
+    }
+
+    /**
+     * Get the input stream associated with this socket.
+     * <p>The input stream will be returned even if the socket is not yet
+     * connected, but operations on that stream will throw IOException until
+     * the associated socket is connected.
+     *
+     * @return InputStream
+     */
+    @RequiresNoPermission
+    public InputStream getInputStream() throws IOException {
+        return mInputStream;
+    }
+
+    /**
+     * Get the output stream associated with this socket.
+     * <p>The output stream will be returned even if the socket is not yet
+     * connected, but operations on that stream will throw IOException until
+     * the associated socket is connected.
+     *
+     * @return OutputStream
+     */
+    @RequiresNoPermission
+    public OutputStream getOutputStream() throws IOException {
+        return mOutputStream;
+    }
+
+    /**
+     * Get the connection status of this socket, ie, whether there is an active connection with
+     * remote device.
+     *
+     * @return true if connected false if not connected
+     */
+    @RequiresNoPermission
+    public boolean isConnected() {
+        return mSocketState == SocketState.CONNECTED;
+    }
+
+    /*package*/ void setServiceName(String name) {
+        mServiceName = name;
+    }
+
+    /**
+     * Attempt to connect to a remote device.
+     * <p>This method will block until a connection is made or the connection
+     * fails. If this method returns without an exception then this socket
+     * is now connected.
+     * <p>Creating new connections to
+     * remote Bluetooth devices should not be attempted while device discovery
+     * is in progress. Device discovery is a heavyweight procedure on the
+     * Bluetooth adapter and will significantly slow a device connection.
+     * Use {@link BluetoothAdapter#cancelDiscovery()} to cancel an ongoing
+     * discovery. Discovery is not managed by the Activity,
+     * but is run as a system service, so an application should always call
+     * {@link BluetoothAdapter#cancelDiscovery()} even if it
+     * did not directly request a discovery, just to be sure.
+     * <p>{@link #close} can be used to abort this call from another thread.
+     *
+     * @throws IOException on error, for example connection failure
+     */
+    @RequiresBluetoothConnectPermission
+    @RequiresPermission(android.Manifest.permission.BLUETOOTH_CONNECT)
+    public void connect() throws IOException {
+        if (mDevice == null) throw new IOException("Connect is called on null device");
+
+        try {
+            if (mSocketState == SocketState.CLOSED) throw new IOException("socket closed");
+            IBluetooth bluetoothProxy =
+                    BluetoothAdapter.getDefaultAdapter().getBluetoothService();
+            if (bluetoothProxy == null) throw new IOException("Bluetooth is off");
+            mPfd = bluetoothProxy.getSocketManager().connectSocket(mDevice, mType,
+                    mUuid, mPort, getSecurityFlags());
+            synchronized (this) {
+                if (DBG) Log.d(TAG, "connect(), SocketState: " + mSocketState + ", mPfd: " + mPfd);
+                if (mSocketState == SocketState.CLOSED) throw new IOException("socket closed");
+                if (mPfd == null) throw new IOException("bt socket connect failed");
+                FileDescriptor fd = mPfd.getFileDescriptor();
+                mSocket = LocalSocket.createConnectedLocalSocket(fd);
+                mSocketIS = mSocket.getInputStream();
+                mSocketOS = mSocket.getOutputStream();
+            }
+            int channel = readInt(mSocketIS);
+            if (channel <= 0) {
+                throw new IOException("bt socket connect failed");
+            }
+            mPort = channel;
+            waitSocketSignal(mSocketIS);
+            synchronized (this) {
+                if (mSocketState == SocketState.CLOSED) {
+                    throw new IOException("bt socket closed");
+                }
+                mSocketState = SocketState.CONNECTED;
+            }
+        } catch (RemoteException e) {
+            Log.e(TAG, Log.getStackTraceString(new Throwable()));
+            throw new IOException("unable to send RPC: " + e.getMessage());
+        }
+    }
+
+    /**
+     * Currently returns unix errno instead of throwing IOException,
+     * so that BluetoothAdapter can check the error code for EADDRINUSE
+     */
+    @RequiresPermission(android.Manifest.permission.BLUETOOTH_CONNECT)
+    /*package*/ int bindListen() {
+        int ret;
+        if (mSocketState == SocketState.CLOSED) return EBADFD;
+        IBluetooth bluetoothProxy = BluetoothAdapter.getDefaultAdapter().getBluetoothService();
+        if (bluetoothProxy == null) {
+            Log.e(TAG, "bindListen fail, reason: bluetooth is off");
+            return -1;
+        }
+        try {
+            if (DBG) Log.d(TAG, "bindListen(): mPort=" + mPort + ", mType=" + mType);
+            mPfd = bluetoothProxy.getSocketManager().createSocketChannel(mType, mServiceName,
+                    mUuid, mPort, getSecurityFlags());
+        } catch (RemoteException e) {
+            Log.e(TAG, Log.getStackTraceString(new Throwable()));
+            return -1;
+        }
+
+        // read out port number
+        try {
+            synchronized (this) {
+                if (DBG) {
+                    Log.d(TAG, "bindListen(), SocketState: " + mSocketState + ", mPfd: " + mPfd);
+                }
+                if (mSocketState != SocketState.INIT) return EBADFD;
+                if (mPfd == null) return -1;
+                FileDescriptor fd = mPfd.getFileDescriptor();
+                if (fd == null) {
+                    Log.e(TAG, "bindListen(), null file descriptor");
+                    return -1;
+                }
+
+                if (DBG) Log.d(TAG, "bindListen(), Create LocalSocket");
+                mSocket = LocalSocket.createConnectedLocalSocket(fd);
+                if (DBG) Log.d(TAG, "bindListen(), new LocalSocket.getInputStream()");
+                mSocketIS = mSocket.getInputStream();
+                mSocketOS = mSocket.getOutputStream();
+            }
+            if (DBG) Log.d(TAG, "bindListen(), readInt mSocketIS: " + mSocketIS);
+            int channel = readInt(mSocketIS);
+            synchronized (this) {
+                if (mSocketState == SocketState.INIT) {
+                    mSocketState = SocketState.LISTENING;
+                }
+            }
+            if (DBG) Log.d(TAG, "bindListen(): channel=" + channel + ", mPort=" + mPort);
+            if (mPort <= -1) {
+                mPort = channel;
+            } // else ASSERT(mPort == channel)
+            ret = 0;
+        } catch (IOException e) {
+            if (mPfd != null) {
+                try {
+                    mPfd.close();
+                } catch (IOException e1) {
+                    Log.e(TAG, "bindListen, close mPfd: " + e1);
+                }
+                mPfd = null;
+            }
+            Log.e(TAG, "bindListen, fail to get port number, exception: " + e);
+            return -1;
+        }
+        return ret;
+    }
+
+    /*package*/ BluetoothSocket accept(int timeout) throws IOException {
+        BluetoothSocket acceptedSocket;
+        if (mSocketState != SocketState.LISTENING) {
+            throw new IOException("bt socket is not in listen state");
+        }
+        if (timeout > 0) {
+            Log.d(TAG, "accept() set timeout (ms):" + timeout);
+            mSocket.setSoTimeout(timeout);
+        }
+        String RemoteAddr = waitSocketSignal(mSocketIS);
+        if (timeout > 0) {
+            mSocket.setSoTimeout(0);
+        }
+        synchronized (this) {
+            if (mSocketState != SocketState.LISTENING) {
+                throw new IOException("bt socket is not in listen state");
+            }
+            acceptedSocket = acceptSocket(RemoteAddr);
+            //quick drop the reference of the file handle
+        }
+        return acceptedSocket;
+    }
+
+    /*package*/ int available() throws IOException {
+        if (VDBG) Log.d(TAG, "available: " + mSocketIS);
+        return mSocketIS.available();
+    }
+
+    /*package*/ int read(byte[] b, int offset, int length) throws IOException {
+        int ret = 0;
+        if (VDBG) Log.d(TAG, "read in:  " + mSocketIS + " len: " + length);
+        if ((mType == TYPE_L2CAP) || (mType == TYPE_L2CAP_LE)) {
+            int bytesToRead = length;
+            if (VDBG) {
+                Log.v(TAG, "l2cap: read(): offset: " + offset + " length:" + length
+                        + "mL2capBuffer= " + mL2capBuffer);
+            }
+            if (mL2capBuffer == null) {
+                createL2capRxBuffer();
+            }
+            if (mL2capBuffer.remaining() == 0) {
+                if (VDBG) Log.v(TAG, "l2cap buffer empty, refilling...");
+                if (fillL2capRxBuffer() == -1) {
+                    return -1;
+                }
+            }
+            if (bytesToRead > mL2capBuffer.remaining()) {
+                bytesToRead = mL2capBuffer.remaining();
+            }
+            if (VDBG) {
+                Log.v(TAG, "get(): offset: " + offset
+                        + " bytesToRead: " + bytesToRead);
+            }
+            mL2capBuffer.get(b, offset, bytesToRead);
+            ret = bytesToRead;
+        } else {
+            if (VDBG) Log.v(TAG, "default: read(): offset: " + offset + " length:" + length);
+            ret = mSocketIS.read(b, offset, length);
+        }
+        if (ret < 0) {
+            throw new IOException("bt socket closed, read return: " + ret);
+        }
+        if (VDBG) Log.d(TAG, "read out:  " + mSocketIS + " ret: " + ret);
+        return ret;
+    }
+
+    /*package*/ int write(byte[] b, int offset, int length) throws IOException {
+
+        //TODO: Since bindings can exist between the SDU size and the
+        //      protocol, we might need to throw an exception instead of just
+        //      splitting the write into multiple smaller writes.
+        //      Rfcomm uses dynamic allocation, and should not have any bindings
+        //      to the actual message length.
+        if (VDBG) Log.d(TAG, "write: " + mSocketOS + " length: " + length);
+        if ((mType == TYPE_L2CAP) || (mType == TYPE_L2CAP_LE)) {
+            if (length <= mMaxTxPacketSize) {
+                mSocketOS.write(b, offset, length);
+            } else {
+                if (DBG) {
+                    Log.w(TAG, "WARNING: Write buffer larger than L2CAP packet size!\n"
+                            + "Packet will be divided into SDU packets of size "
+                            + mMaxTxPacketSize);
+                }
+                int tmpOffset = offset;
+                int bytesToWrite = length;
+                while (bytesToWrite > 0) {
+                    int tmpLength = (bytesToWrite > mMaxTxPacketSize)
+                            ? mMaxTxPacketSize
+                            : bytesToWrite;
+                    mSocketOS.write(b, tmpOffset, tmpLength);
+                    tmpOffset += tmpLength;
+                    bytesToWrite -= tmpLength;
+                }
+            }
+        } else {
+            mSocketOS.write(b, offset, length);
+        }
+        // There is no good way to confirm since the entire process is asynchronous anyway
+        if (VDBG) Log.d(TAG, "write out: " + mSocketOS + " length: " + length);
+        return length;
+    }
+
+    @Override
+    public void close() throws IOException {
+        Log.d(TAG, "close() this: " + this + ", channel: " + mPort + ", mSocketIS: " + mSocketIS
+                + ", mSocketOS: " + mSocketOS + "mSocket: " + mSocket + ", mSocketState: "
+                + mSocketState);
+        if (mSocketState == SocketState.CLOSED) {
+            return;
+        } else {
+            synchronized (this) {
+                if (mSocketState == SocketState.CLOSED) {
+                    return;
+                }
+                mSocketState = SocketState.CLOSED;
+                if (mSocket != null) {
+                    if (DBG) Log.d(TAG, "Closing mSocket: " + mSocket);
+                    mSocket.shutdownInput();
+                    mSocket.shutdownOutput();
+                    mSocket.close();
+                    mSocket = null;
+                }
+                if (mPfd != null) {
+                    mPfd.close();
+                    mPfd = null;
+                }
+            }
+        }
+    }
+
+    /*package */ void removeChannel() {
+    }
+
+    /*package */ int getPort() {
+        return mPort;
+    }
+
+    /**
+     * Get the maximum supported Transmit packet size for the underlying transport.
+     * Use this to optimize the writes done to the output socket, to avoid sending
+     * half full packets.
+     *
+     * @return the maximum supported Transmit packet size for the underlying transport.
+     */
+    @RequiresNoPermission
+    public int getMaxTransmitPacketSize() {
+        return mMaxTxPacketSize;
+    }
+
+    /**
+     * Get the maximum supported Receive packet size for the underlying transport.
+     * Use this to optimize the reads done on the input stream, as any call to read
+     * will return a maximum of this amount of bytes - or for some transports a
+     * multiple of this value.
+     *
+     * @return the maximum supported Receive packet size for the underlying transport.
+     */
+    @RequiresNoPermission
+    public int getMaxReceivePacketSize() {
+        return mMaxRxPacketSize;
+    }
+
+    /**
+     * Get the type of the underlying connection.
+     *
+     * @return one of {@link #TYPE_RFCOMM}, {@link #TYPE_SCO} or {@link #TYPE_L2CAP}
+     */
+    @RequiresNoPermission
+    public int getConnectionType() {
+        if (mType == TYPE_L2CAP_LE) {
+            // Treat the LE CoC to be the same type as L2CAP.
+            return TYPE_L2CAP;
+        }
+        return mType;
+    }
+
+    /**
+     * Change if a SDP entry should be automatically created.
+     * Must be called before calling .bind, for the call to have any effect.
+     *
+     * @param excludeSdp <li>TRUE - do not auto generate SDP record. <li>FALSE - default - auto
+     * generate SPP SDP record.
+     * @hide
+     */
+    @RequiresNoPermission
+    public void setExcludeSdp(boolean excludeSdp) {
+        mExcludeSdp = excludeSdp;
+    }
+
+    /**
+     * Set the LE Transmit Data Length to be the maximum that the BT Controller is capable of. This
+     * parameter is used by the BT Controller to set the maximum transmission packet size on this
+     * connection. This function is currently used for testing only.
+     * @hide
+     */
+    @RequiresBluetoothConnectPermission
+    @RequiresPermission(android.Manifest.permission.BLUETOOTH_CONNECT)
+    public void requestMaximumTxDataLength() throws IOException {
+        if (mDevice == null) {
+            throw new IOException("requestMaximumTxDataLength is called on null device");
+        }
+
+        try {
+            if (mSocketState == SocketState.CLOSED) {
+                throw new IOException("socket closed");
+            }
+            IBluetooth bluetoothProxy =
+                    BluetoothAdapter.getDefaultAdapter().getBluetoothService();
+            if (bluetoothProxy == null) {
+                throw new IOException("Bluetooth is off");
+            }
+
+            if (DBG) Log.d(TAG, "requestMaximumTxDataLength");
+            bluetoothProxy.getSocketManager().requestMaximumTxDataLength(mDevice);
+        } catch (RemoteException e) {
+            Log.e(TAG, Log.getStackTraceString(new Throwable()));
+            throw new IOException("unable to send RPC: " + e.getMessage());
+        }
+    }
+
+    private String convertAddr(final byte[] addr) {
+        return String.format(Locale.US, "%02X:%02X:%02X:%02X:%02X:%02X",
+                addr[0], addr[1], addr[2], addr[3], addr[4], addr[5]);
+    }
+
+    private String waitSocketSignal(InputStream is) throws IOException {
+        byte[] sig = new byte[SOCK_SIGNAL_SIZE];
+        int ret = readAll(is, sig);
+        if (VDBG) {
+            Log.d(TAG, "waitSocketSignal read " + SOCK_SIGNAL_SIZE + " bytes signal ret: " + ret);
+        }
+        ByteBuffer bb = ByteBuffer.wrap(sig);
+        /* the struct in native is decorated with __attribute__((packed)), hence this is possible */
+        bb.order(ByteOrder.nativeOrder());
+        int size = bb.getShort();
+        if (size != SOCK_SIGNAL_SIZE) {
+            throw new IOException("Connection failure, wrong signal size: " + size);
+        }
+        byte[] addr = new byte[6];
+        bb.get(addr);
+        int channel = bb.getInt();
+        int status = bb.getInt();
+        mMaxTxPacketSize = (bb.getShort() & 0xffff); // Convert to unsigned value
+        mMaxRxPacketSize = (bb.getShort() & 0xffff); // Convert to unsigned value
+        String RemoteAddr = convertAddr(addr);
+        if (VDBG) {
+            Log.d(TAG, "waitSocketSignal: sig size: " + size + ", remote addr: "
+                    + RemoteAddr + ", channel: " + channel + ", status: " + status
+                    + " MaxRxPktSize: " + mMaxRxPacketSize + " MaxTxPktSize: " + mMaxTxPacketSize);
+        }
+        if (status != 0) {
+            throw new IOException("Connection failure, status: " + status);
+        }
+        return RemoteAddr;
+    }
+
+    private void createL2capRxBuffer() {
+        if ((mType == TYPE_L2CAP) || (mType == TYPE_L2CAP_LE)) {
+            // Allocate the buffer to use for reads.
+            if (VDBG) Log.v(TAG, "  Creating mL2capBuffer: mMaxPacketSize: " + mMaxRxPacketSize);
+            mL2capBuffer = ByteBuffer.wrap(new byte[mMaxRxPacketSize]);
+            if (VDBG) Log.v(TAG, "mL2capBuffer.remaining()" + mL2capBuffer.remaining());
+            mL2capBuffer.limit(0); // Ensure we do a real read at the first read-request
+            if (VDBG) {
+                Log.v(TAG, "mL2capBuffer.remaining() after limit(0):" + mL2capBuffer.remaining());
+            }
+        }
+    }
+
+    private int readAll(InputStream is, byte[] b) throws IOException {
+        int left = b.length;
+        while (left > 0) {
+            int ret = is.read(b, b.length - left, left);
+            if (ret <= 0) {
+                throw new IOException("read failed, socket might closed or timeout, read ret: "
+                        + ret);
+            }
+            left -= ret;
+            if (left != 0) {
+                Log.w(TAG, "readAll() looping, read partial size: " + (b.length - left)
+                        + ", expect size: " + b.length);
+            }
+        }
+        return b.length;
+    }
+
+    private int readInt(InputStream is) throws IOException {
+        byte[] ibytes = new byte[4];
+        int ret = readAll(is, ibytes);
+        if (VDBG) Log.d(TAG, "inputStream.read ret: " + ret);
+        ByteBuffer bb = ByteBuffer.wrap(ibytes);
+        bb.order(ByteOrder.nativeOrder());
+        return bb.getInt();
+    }
+
+    private int fillL2capRxBuffer() throws IOException {
+        mL2capBuffer.rewind();
+        int ret = mSocketIS.read(mL2capBuffer.array());
+        if (ret == -1) {
+            // reached end of stream - return -1
+            mL2capBuffer.limit(0);
+            return -1;
+        }
+        mL2capBuffer.limit(ret);
+        return ret;
+    }
+
+
+}