1/*
2 * Copyright (C) 2010 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.net.rtp;
18
19import java.net.InetAddress;
20import java.net.Inet4Address;
21import java.net.Inet6Address;
22import java.net.SocketException;
23
24/**
25 * RtpStream represents the base class of streams which send and receive network
26 * packets with media payloads over Real-time Transport Protocol (RTP).
27 *
28 * <p class="note">Using this class requires
29 * {@link android.Manifest.permission#INTERNET} permission.</p>
30 */
31public class RtpStream {
32    /**
33     * This mode indicates that the stream sends and receives packets at the
34     * same time. This is the initial mode for new streams.
35     */
36    public static final int MODE_NORMAL = 0;
37
38    /**
39     * This mode indicates that the stream only sends packets.
40     */
41    public static final int MODE_SEND_ONLY = 1;
42
43    /**
44     * This mode indicates that the stream only receives packets.
45     */
46    public static final int MODE_RECEIVE_ONLY = 2;
47
48    private static final int MODE_LAST = 2;
49
50    private final InetAddress mLocalAddress;
51    private final int mLocalPort;
52
53    private InetAddress mRemoteAddress;
54    private int mRemotePort = -1;
55    private int mMode = MODE_NORMAL;
56
57    private int mSocket = -1;
58    static {
59        System.loadLibrary("rtp_jni");
60    }
61
62    /**
63     * Creates a RtpStream on the given local address. Note that the local
64     * port is assigned automatically to conform with RFC 3550.
65     *
66     * @param address The network address of the local host to bind to.
67     * @throws SocketException if the address cannot be bound or a problem
68     *     occurs during binding.
69     */
70    RtpStream(InetAddress address) throws SocketException {
71        mLocalPort = create(address.getHostAddress());
72        mLocalAddress = address;
73    }
74
75    private native int create(String address) throws SocketException;
76
77    /**
78     * Returns the network address of the local host.
79     */
80    public InetAddress getLocalAddress() {
81        return mLocalAddress;
82    }
83
84    /**
85     * Returns the network port of the local host.
86     */
87    public int getLocalPort() {
88        return mLocalPort;
89    }
90
91    /**
92     * Returns the network address of the remote host or {@code null} if the
93     * stream is not associated.
94     */
95    public InetAddress getRemoteAddress() {
96        return mRemoteAddress;
97    }
98
99    /**
100     * Returns the network port of the remote host or {@code -1} if the stream
101     * is not associated.
102     */
103    public int getRemotePort() {
104        return mRemotePort;
105    }
106
107    /**
108     * Returns {@code true} if the stream is busy. In this case most of the
109     * setter methods are disabled. This method is intended to be overridden
110     * by subclasses.
111     */
112    public boolean isBusy() {
113        return false;
114    }
115
116    /**
117     * Returns the current mode.
118     */
119    public int getMode() {
120        return mMode;
121    }
122
123    /**
124     * Changes the current mode. It must be one of {@link #MODE_NORMAL},
125     * {@link #MODE_SEND_ONLY}, and {@link #MODE_RECEIVE_ONLY}.
126     *
127     * @param mode The mode to change to.
128     * @throws IllegalArgumentException if the mode is invalid.
129     * @throws IllegalStateException if the stream is busy.
130     * @see #isBusy()
131     */
132    public void setMode(int mode) {
133        if (isBusy()) {
134            throw new IllegalStateException("Busy");
135        }
136        if (mode < 0 || mode > MODE_LAST) {
137            throw new IllegalArgumentException("Invalid mode");
138        }
139        mMode = mode;
140    }
141
142    /**
143     * Associates with a remote host. This defines the destination of the
144     * outgoing packets.
145     *
146     * @param address The network address of the remote host.
147     * @param port The network port of the remote host.
148     * @throws IllegalArgumentException if the address is not supported or the
149     *     port is invalid.
150     * @throws IllegalStateException if the stream is busy.
151     * @see #isBusy()
152     */
153    public void associate(InetAddress address, int port) {
154        if (isBusy()) {
155            throw new IllegalStateException("Busy");
156        }
157        if (!(address instanceof Inet4Address && mLocalAddress instanceof Inet4Address) &&
158                !(address instanceof Inet6Address && mLocalAddress instanceof Inet6Address)) {
159            throw new IllegalArgumentException("Unsupported address");
160        }
161        if (port < 0 || port > 65535) {
162            throw new IllegalArgumentException("Invalid port");
163        }
164        mRemoteAddress = address;
165        mRemotePort = port;
166    }
167
168    int getSocket() {
169        return mSocket;
170    }
171
172    /**
173     * Releases allocated resources. The stream becomes inoperable after calling
174     * this method.
175     *
176     * @throws IllegalStateException if the stream is busy.
177     * @see #isBusy()
178     */
179    public void release() {
180        synchronized (this) {
181            if (isBusy()) {
182                throw new IllegalStateException("Busy");
183            }
184            close();
185        }
186    }
187
188    private native void close();
189
190    @Override
191    protected void finalize() throws Throwable {
192        close();
193        super.finalize();
194    }
195}
196