1/*
2 * Copyright (C) 2011 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 com.android.nfc.ndefpush;
18
19import com.android.nfc.DeviceHost.LlcpSocket;
20import com.android.nfc.LlcpException;
21import com.android.nfc.NfcService;
22
23import android.nfc.NdefMessage;
24import android.util.Log;
25
26import java.io.IOException;
27import java.util.Arrays;
28
29/**
30 * Simple client to push the local NDEF message to a server on the remote side of an
31 * LLCP connection, using the Android Ndef Push Protocol.
32 */
33public class NdefPushClient {
34    private static final String TAG = "NdefPushClient";
35    private static final int MIU = 128;
36    private static final boolean DBG = true;
37
38    private static final int DISCONNECTED = 0;
39    private static final int CONNECTING = 1;
40    private static final int CONNECTED = 2;
41
42    final Object mLock = new Object();
43    // Variables below locked on mLock
44    private int mState = DISCONNECTED;
45    private LlcpSocket mSocket;
46
47    public void connect() throws IOException {
48        synchronized (mLock) {
49            if (mState != DISCONNECTED) {
50                throw new IOException("Socket still in use.");
51            }
52            mState = CONNECTING;
53        }
54        NfcService service = NfcService.getInstance();
55        LlcpSocket sock = null;
56        if (DBG) Log.d(TAG, "about to create socket");
57        try {
58            sock = service.createLlcpSocket(0, MIU, 1, 1024);
59        } catch (LlcpException e) {
60            synchronized (mLock) {
61                mState = DISCONNECTED;
62            }
63            throw new IOException("Could not create socket.");
64        }
65        try {
66            if (DBG) Log.d(TAG, "about to connect to service " + NdefPushServer.SERVICE_NAME);
67            sock.connectToService(NdefPushServer.SERVICE_NAME);
68        } catch (IOException e) {
69            if (sock != null) {
70                try {
71                    sock.close();
72                } catch (IOException e2) {
73
74                }
75            }
76            synchronized (mLock) {
77                mState = DISCONNECTED;
78            }
79            throw new IOException("Could not connect service.");
80        }
81
82        synchronized (mLock) {
83            mSocket = sock;
84            mState = CONNECTED;
85        }
86    }
87
88    public boolean push(NdefMessage msg) {
89        LlcpSocket sock = null;
90        synchronized (mLock) {
91            if (mState != CONNECTED) {
92                Log.e(TAG, "Not connected to NPP.");
93                return false;
94            }
95            sock = mSocket;
96        }
97        // We only handle a single immediate action for now
98        NdefPushProtocol proto = new NdefPushProtocol(msg, NdefPushProtocol.ACTION_IMMEDIATE);
99        byte[] buffer = proto.toByteArray();
100        int offset = 0;
101        int remoteMiu;
102
103        try {
104            remoteMiu = sock.getRemoteMiu();
105            if (DBG) Log.d(TAG, "about to send a " + buffer.length + " byte message");
106            while (offset < buffer.length) {
107                int length = Math.min(buffer.length - offset, remoteMiu);
108                byte[] tmpBuffer = Arrays.copyOfRange(buffer, offset, offset+length);
109                if (DBG) Log.d(TAG, "about to send a " + length + " byte packet");
110                sock.send(tmpBuffer);
111                offset += length;
112            }
113            return true;
114        } catch (IOException e) {
115            Log.e(TAG, "couldn't send tag");
116            if (DBG) Log.d(TAG, "exception:", e);
117        } finally {
118            if (sock != null) {
119                try {
120                    if (DBG) Log.d(TAG, "about to close");
121                    sock.close();
122                } catch (IOException e) {
123                    // Ignore
124                }
125            }
126        }
127        return false;
128    }
129
130    public void close() {
131        synchronized (mLock) {
132            if (mSocket != null) {
133                try {
134                    if (DBG) Log.d(TAG, "About to close NPP socket.");
135                    mSocket.close();
136                } catch (IOException e) {
137                    // Ignore
138                }
139                mSocket = null;
140            }
141            mState = DISCONNECTED;
142        }
143    }
144}
145