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 com.android.dumprendertree2.forwarder;
18
19import android.util.Log;
20
21import java.io.IOException;
22import java.net.ServerSocket;
23import java.net.Socket;
24import java.util.HashSet;
25import java.util.Set;
26
27/**
28 * A port forwarding server. Listens on localhost on specified port and forwards the tcp
29 * communications to external socket via adb networking proxy.
30 */
31public class Forwarder extends Thread {
32    private static final String LOG_TAG = "Forwarder";
33
34    private int mPort;
35    private String mRemoteMachineIpAddress;
36
37    private ServerSocket mServerSocket;
38
39    private Set<ConnectionHandler> mConnectionHandlers = new HashSet<ConnectionHandler>();
40
41    public Forwarder(int port, String remoteMachineIpAddress) {
42        mPort = port;
43        mRemoteMachineIpAddress = remoteMachineIpAddress;
44    }
45
46    @Override
47    public void start() {
48        Log.i(LOG_TAG, "start(): Starting fowarder on port: " + mPort);
49
50        try {
51            mServerSocket = new ServerSocket(mPort);
52        } catch (IOException e) {
53            Log.e(LOG_TAG, "mPort=" + mPort, e);
54            return;
55        }
56
57        super.start();
58    }
59
60    @Override
61    public void run() {
62        while (true) {
63            Socket localSocket;
64            try {
65                localSocket = mServerSocket.accept();
66            } catch (IOException e) {
67                /** This most likely means that mServerSocket is already closed */
68                Log.w(LOG_TAG, "mPort=" + mPort, e);
69                break;
70            }
71
72            Socket remoteSocket = null;
73            final ConnectionHandler connectionHandler;
74            try {
75                remoteSocket = AdbUtils.createSocket();
76                connectionHandler = new ConnectionHandler(
77                        mRemoteMachineIpAddress, mPort, localSocket, remoteSocket);
78            } catch (IOException exception) {
79                try {
80                    localSocket.close();
81                } catch (IOException e) {
82                    Log.e(LOG_TAG, "mPort=" + mPort, e);
83                }
84                if (remoteSocket != null) {
85                    try {
86                        remoteSocket.close();
87                    } catch (IOException e) {
88                        Log.e(LOG_TAG, "mPort=" + mPort, e);
89                    }
90                }
91                continue;
92            }
93
94            /**
95             * We have to close the sockets after the ConnectionHandler finishes, so we
96             * don't get "Too may open files" exception. We also remove the ConnectionHandler
97             * from the collection to avoid memory issues.
98             * */
99            ConnectionHandler.OnFinishedCallback callback =
100                    new ConnectionHandler.OnFinishedCallback() {
101                @Override
102                public void onFinished() {
103                    synchronized (this) {
104                        if (!mConnectionHandlers.remove(connectionHandler)) {
105                            assert false : "removeConnectionHandler(): not in the collection";
106                        }
107                    }
108                }
109            };
110            connectionHandler.registerOnConnectionHandlerFinishedCallback(callback);
111
112            synchronized (this) {
113                mConnectionHandlers.add(connectionHandler);
114            }
115            connectionHandler.start();
116        }
117
118        synchronized (this) {
119            for (ConnectionHandler connectionHandler : mConnectionHandlers) {
120                connectionHandler.stop();
121            }
122        }
123    }
124
125    public void finish() {
126        try {
127            mServerSocket.close();
128        } catch (IOException e) {
129            Log.e(LOG_TAG, "mPort=" + mPort, e);
130        }
131    }
132}
133