src/app/qtlocalpeer/qtlocalpeer.cpp

   1 /*
   2  * Bittorrent Client using Qt and libtorrent.
   3  * Copyright (C) 2019  Mike Tzou (Chocobo1)
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License
   7  * as published by the Free Software Foundation; either version 2
   8  * of the License, or (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  18  *
  19  * In addition, as a special exception, the copyright holders give permission to
  20  * link this program with the OpenSSL project's "OpenSSL" library (or with
  21  * modified versions of it that use the same license as the "OpenSSL" library),
  22  * and distribute the linked executables. You must obey the GNU General Public
  23  * License in all respects for all of the code used other than "OpenSSL".  If you
  24  * modify file(s), you may extend this exception to your version of the file(s),
  25  * but you are not obligated to do so. If you do not wish to do so, delete this
  26  * exception statement from your version.
  27  *
  28 ****************************************************************************
  29 **
  30 ** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
  31 ** Contact: http://www.qt-project.org/legal
  32 **
  33 ** This file is part of the Qt Solutions component.
  34 **
  35 ** $QT_BEGIN_LICENSE:BSD$
  36 ** You may use this file under the terms of the BSD license as follows:
  37 **
  38 ** "Redistribution and use in source and binary forms, with or without
  39 ** modification, are permitted provided that the following conditions are
  40 ** met:
  41 **   * Redistributions of source code must retain the above copyright
  42 **     notice, this list of conditions and the following disclaimer.
  43 **   * Redistributions in binary form must reproduce the above copyright
  44 **     notice, this list of conditions and the following disclaimer in
  45 **     the documentation and/or other materials provided with the
  46 **     distribution.
  47 **   * Neither the name of Digia Plc and its Subsidiary(-ies) nor the names
  48 **     of its contributors may be used to endorse or promote products derived
  49 **     from this software without specific prior written permission.
  50 **
  51 **
  52 ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  53 ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  54 ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  55 ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  56 ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  57 ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  58 ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  59 ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  60 ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  61 ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  62 ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
  63 **
  64 ** $QT_END_LICENSE$
  65 **
  66 ****************************************************************************
  67 */
  68
  69 #include "qtlocalpeer.h"
  70
  71 #include <QtSystemDetection>
  72
  73 #if defined(Q_OS_WIN)
  74 #include <windows.h>
  75 #endif
  76
  77 #include <QByteArray>
  78 #include <QDataStream>
  79 #include <QFileInfo>
  80 #include <QLocalServer>
  81 #include <QLocalSocket>
  82
  83 namespace QtLP_Private
  84 {
  85 #include "qtlockedfile.cpp"
  86
  87 #if defined(Q_OS_WIN)
  88 #include "qtlockedfile_win.cpp"
  89 #else
  90 #include "qtlockedfile_unix.cpp"
  91 #endif
  92 }
  93
  94 const QByteArray ACK = QByteArrayLiteral("ack");
  95
  96 QtLocalPeer::QtLocalPeer(const QString &path, QObject *parent)
  97     : QObject(parent)
  98     , m_socketName(path + u"/ipc-socket")
  99     , m_server(new QLocalServer(this))
 100 {
 101     m_server->setSocketOptions(QLocalServer::UserAccessOption);
 102
 103     m_lockFile.setFileName(path + u"/lockfile");
 104     m_lockFile.open(QIODevice::ReadWrite);
 105 }
 106
 107 QtLocalPeer::~QtLocalPeer()
 108 {
 109     if (!isClient())
 110     {
 111         m_lockFile.unlock();
 112         m_lockFile.remove();
 113     }
 114 }
 115
 116 bool QtLocalPeer::isClient()
 117 {
 118     if (m_lockFile.isLocked())
 119         return false;
 120
 121     if (!m_lockFile.lock(QtLP_Private::QtLockedFile::WriteLock, false))
 122         return true;
 123
 124     bool res = m_server->listen(m_socketName);
 125 #if defined(Q_OS_UNIX)
 126     // ### Workaround
 127     if (!res && m_server->serverError() == QAbstractSocket::AddressInUseError)
 128     {
 129         QFile::remove(m_socketName);
 130         res = m_server->listen(m_socketName);
 131     }
 132 #endif
 133     if (!res)
 134         qWarning("QtSingleCoreApplication: listen on local socket failed, %s", qUtf8Printable(m_server->errorString()));
 135
 136     connect(m_server, &QLocalServer::newConnection, this, &QtLocalPeer::receiveConnection);
 137     return false;
 138 }
 139
 140 bool QtLocalPeer::sendMessage(const QString &message, const int timeout)
 141 {
 142     if (!isClient())
 143         return false;
 144
 145     QLocalSocket socket;
 146     bool connOk = false;
 147     for(int i = 0; i < 2; i++)
 148     {
 149         // Try twice, in case the other instance is just starting up
 150         socket.connectToServer(m_socketName);
 151         connOk = socket.waitForConnected(timeout/2);
 152         if (connOk || i)
 153             break;
 154         int ms = 250;
 155 #if defined(Q_OS_WIN)
 156         ::Sleep(DWORD(ms));
 157 #else
 158         struct timespec ts = { ms / 1000, (ms % 1000) * 1000 * 1000 };
 159         ::nanosleep(&ts, nullptr);
 160 #endif
 161     }
 162     if (!connOk)
 163         return false;
 164
 165     QByteArray uMsg(message.toUtf8());
 166     QDataStream ds(&socket);
 167     ds.writeBytes(uMsg.constData(), uMsg.size());
 168     bool res = socket.waitForBytesWritten(timeout);
 169     if (res)
 170     {
 171         res &= socket.waitForReadyRead(timeout);   // wait for ack
 172         if (res)
 173             res &= (socket.read(ACK.size()) == ACK);
 174     }
 175     return res;
 176 }
 177
 178 void QtLocalPeer::receiveConnection()
 179 {
 180     QLocalSocket *socket = m_server->nextPendingConnection();
 181     if (!socket)
 182         return;
 183
 184     while (true)
 185     {
 186         if (socket->state() == QLocalSocket::UnconnectedState)
 187         {
 188             qWarning("QtLocalPeer: Peer disconnected");
 189             delete socket;
 190             return;
 191         }
 192         if (socket->bytesAvailable() >= qint64(sizeof(quint32)))
 193             break;
 194         socket->waitForReadyRead();
 195     }
 196
 197     QDataStream ds(socket);
 198     QByteArray uMsg;
 199     quint32 remaining;
 200     ds >> remaining;
 201     if (remaining > 65535)
 202     {
 203         // drop suspiciously large data
 204         delete socket;
 205         return;
 206     }
 207
 208     uMsg.resize(remaining);
 209     int got = 0;
 210     char* uMsgBuf = uMsg.data();
 211     do
 212     {
 213         got = ds.readRawData(uMsgBuf, remaining);
 214         remaining -= got;
 215         uMsgBuf += got;
 216     } while (remaining && got >= 0 && socket->waitForReadyRead(2000));
 217     if (got < 0)
 218     {
 219         qWarning("QtLocalPeer: Message reception failed %s", socket->errorString().toLatin1().constData());
 220         delete socket;
 221         return;
 222     }
 223     QString message(QString::fromUtf8(uMsg));
 224     socket->write(ACK);
 225     socket->waitForBytesWritten(1000);
 226     socket->waitForDisconnected(1000); // make sure client reads ack
 227     delete socket;
 228     emit messageReceived(message); //### (might take a long time to return)
 229 }