1/*
2 * Copyright (C) 2009 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package android.bluetooth;
18
19import android.os.Handler;
20import android.os.ParcelUuid;
21import android.util.Log;
22
23import java.io.Closeable;
24import java.io.IOException;
25
26/**
27 * A listening Bluetooth socket.
28 *
29 * <p>The interface for Bluetooth Sockets is similar to that of TCP sockets:
30 * {@link java.net.Socket} and {@link java.net.ServerSocket}. On the server
31 * side, use a {@link BluetoothServerSocket} to create a listening server
32 * socket. When a connection is accepted by the {@link BluetoothServerSocket},
33 * it will return a new {@link BluetoothSocket} to manage the connection.
34 * On the client side, use a single {@link BluetoothSocket} to both initiate
35 * an outgoing connection and to manage the connection.
36 *
37 * <p>The most common type of Bluetooth socket is RFCOMM, which is the type
38 * supported by the Android APIs. RFCOMM is a connection-oriented, streaming
39 * transport over Bluetooth. It is also known as the Serial Port Profile (SPP).
40 *
41 * <p>To create a listening {@link BluetoothServerSocket} that's ready for
42 * incoming connections, use
43 * {@link BluetoothAdapter#listenUsingRfcommWithServiceRecord
44 * BluetoothAdapter.listenUsingRfcommWithServiceRecord()}. Then call
45 * {@link #accept()} to listen for incoming connection requests. This call
46 * will block until a connection is established, at which point, it will return
47 * a {@link BluetoothSocket} to manage the connection. Once the {@link
48 * BluetoothSocket} is acquired, it's a good idea to call {@link #close()} on
49 * the {@link BluetoothServerSocket} when it's no longer needed for accepting
50 * connections. Closing the {@link BluetoothServerSocket} will <em>not</em>
51 * close the returned {@link BluetoothSocket}.
52 *
53 * <p>{@link BluetoothServerSocket} is thread
54 * safe. In particular, {@link #close} will always immediately abort ongoing
55 * operations and close the server socket.
56 *
57 * <p class="note"><strong>Note:</strong>
58 * Requires the {@link android.Manifest.permission#BLUETOOTH} permission.
59 *
60 * <div class="special reference">
61 * <h3>Developer Guides</h3>
62 * <p>For more information about using Bluetooth, read the
63 * <a href="{@docRoot}guide/topics/wireless/bluetooth.html">Bluetooth</a> developer guide.</p>
64 * </div>
65 *
66 * {@see BluetoothSocket}
67 */
68public final class BluetoothServerSocket implements Closeable {
69
70    private static final String TAG = "BluetoothServerSocket";
71    /*package*/ final BluetoothSocket mSocket;
72    private Handler mHandler;
73    private int mMessage;
74    private int mChannel;
75
76    /**
77     * Construct a socket for incoming connections.
78     * @param type    type of socket
79     * @param auth    require the remote device to be authenticated
80     * @param encrypt require the connection to be encrypted
81     * @param port    remote port
82     * @throws IOException On error, for example Bluetooth not available, or
83     *                     insufficient privileges
84     */
85    /*package*/ BluetoothServerSocket(int type, boolean auth, boolean encrypt, int port)
86            throws IOException {
87        mChannel = port;
88        mSocket = new BluetoothSocket(type, -1, auth, encrypt, null, port, null);
89        if (port == BluetoothAdapter.SOCKET_CHANNEL_AUTO_STATIC_NO_SDP) {
90            mSocket.setExcludeSdp(true);
91        }
92    }
93
94    /**
95     * Construct a socket for incoming connections.
96     * @param type    type of socket
97     * @param auth    require the remote device to be authenticated
98     * @param encrypt require the connection to be encrypted
99     * @param port    remote port
100     * @param mitm    enforce man-in-the-middle protection for authentication.
101     * @param min16DigitPin enforce a minimum length of 16 digits for a sec mode 2 connection
102     * @throws IOException On error, for example Bluetooth not available, or
103     *                     insufficient privileges
104     */
105    /*package*/ BluetoothServerSocket(int type, boolean auth, boolean encrypt, int port,
106            boolean mitm, boolean min16DigitPin)
107            throws IOException {
108        mChannel = port;
109        mSocket = new BluetoothSocket(type, -1, auth, encrypt, null, port, null, mitm,
110                min16DigitPin);
111        if(port == BluetoothAdapter.SOCKET_CHANNEL_AUTO_STATIC_NO_SDP) {
112            mSocket.setExcludeSdp(true);
113        }
114    }
115
116    /**
117     * Construct a socket for incoming connections.
118     * @param type    type of socket
119     * @param auth    require the remote device to be authenticated
120     * @param encrypt require the connection to be encrypted
121     * @param uuid    uuid
122     * @throws IOException On error, for example Bluetooth not available, or
123     *                     insufficient privileges
124     */
125    /*package*/ BluetoothServerSocket(int type, boolean auth, boolean encrypt, ParcelUuid uuid)
126            throws IOException {
127        mSocket = new BluetoothSocket(type, -1, auth, encrypt, null, -1, uuid);
128        // TODO: This is the same as mChannel = -1 - is this intentional?
129        mChannel = mSocket.getPort();
130    }
131
132
133    /**
134     * Block until a connection is established.
135     * <p>Returns a connected {@link BluetoothSocket} on successful connection.
136     * <p>Once this call returns, it can be called again to accept subsequent
137     * incoming connections.
138     * <p>{@link #close} can be used to abort this call from another thread.
139     * @return a connected {@link BluetoothSocket}
140     * @throws IOException on error, for example this call was aborted, or
141     *                     timeout
142     */
143    public BluetoothSocket accept() throws IOException {
144        return accept(-1);
145    }
146
147    /**
148     * Block until a connection is established, with timeout.
149     * <p>Returns a connected {@link BluetoothSocket} on successful connection.
150     * <p>Once this call returns, it can be called again to accept subsequent
151     * incoming connections.
152     * <p>{@link #close} can be used to abort this call from another thread.
153     * @return a connected {@link BluetoothSocket}
154     * @throws IOException on error, for example this call was aborted, or
155     *                     timeout
156     */
157    public BluetoothSocket accept(int timeout) throws IOException {
158        return mSocket.accept(timeout);
159    }
160
161    /**
162     * Immediately close this socket, and release all associated resources.
163     * <p>Causes blocked calls on this socket in other threads to immediately
164     * throw an IOException.
165     * <p>Closing the {@link BluetoothServerSocket} will <em>not</em>
166     * close any {@link BluetoothSocket} received from {@link #accept()}.
167     */
168    public void close() throws IOException {
169        synchronized (this) {
170            if (mHandler != null) {
171                mHandler.obtainMessage(mMessage).sendToTarget();
172            }
173        }
174        mSocket.close();
175    }
176
177    /*package*/ synchronized void setCloseHandler(Handler handler, int message) {
178        mHandler = handler;
179        mMessage = message;
180    }
181    /*package*/ void setServiceName(String ServiceName) {
182        mSocket.setServiceName(ServiceName);
183    }
184
185    /**
186     * Returns the channel on which this socket is bound.
187     * @hide
188     */
189    public int getChannel() {
190        return mChannel;
191    }
192
193    /**
194     * Sets the channel on which future sockets are bound.
195     * Currently used only when a channel is auto generated.
196     */
197    /*package*/ void setChannel(int newChannel) {
198        /* TODO: From a design/architecture perspective this is wrong.
199         *       The bind operation should be conducted through this class
200         *       and the resulting port should be kept in mChannel, and
201         *       not set from BluetoothAdapter. */
202        if(mSocket != null) {
203            if(mSocket.getPort() != newChannel) {
204                Log.w(TAG,"The port set is different that the underlying port. mSocket.getPort(): "
205                            + mSocket.getPort() + " requested newChannel: " + newChannel);
206            }
207        }
208        mChannel = newChannel;
209    }
210
211    @Override
212    public String toString() {
213        StringBuilder sb = new StringBuilder();
214        sb.append("ServerSocket: Type: ");
215        switch(mSocket.getConnectionType()) {
216            case BluetoothSocket.TYPE_RFCOMM:
217            {
218                sb.append("TYPE_RFCOMM");
219                break;
220            }
221            case BluetoothSocket.TYPE_L2CAP:
222            {
223                sb.append("TYPE_L2CAP");
224                break;
225            }
226            case BluetoothSocket.TYPE_SCO:
227            {
228                sb.append("TYPE_SCO");
229                break;
230            }
231        }
232        sb.append(" Channel: ").append(mChannel);
233        return sb.toString();
234    }
235}
236