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 <QDataStream>
  78 #include <QFileInfo>
  79 #include <QLocalServer>
  80 #include <QLocalSocket>
  81
  82 namespace QtLP_Private
  83 {
  84 #include "qtlockedfile.cpp"
  85
  86 #if defined(Q_OS_WIN)
  87 #include "qtlockedfile_win.cpp"
  88 #else
  89 #include "qtlockedfile_unix.cpp"
  90 #endif
  91 }
  92
  93 const char ACK[] = "ack";
  94
  95 QtLocalPeer::QtLocalPeer(const QString &path, QObject *parent)
  96     : QObject(parent)
  97     , m_socketName(path + u"/ipc-socket")
  98     , m_server(new QLocalServer(this))
  99 {
 100     m_server->setSocketOptions(QLocalServer::UserAccessOption);
 101
 102     m_lockFile.setFileName(path + u"/lockfile");
 103     m_lockFile.open(QIODevice::ReadWrite);
 104 }
 105
 106 QtLocalPeer::~QtLocalPeer()
 107 {
 108     if (!isClient())
 109     {
 110         m_lockFile.unlock();
 111         m_lockFile.remove();
 112     }
 113 }
 114
 115 bool QtLocalPeer::isClient()
 116 {
 117     if (m_lockFile.isLocked())
 118         return false;
 119
 120     if (!m_lockFile.lock(QtLP_Private::QtLockedFile::WriteLock, false))
 121         return true;
 122
 123     bool res = m_server->listen(m_socketName);
 124 #if defined(Q_OS_UNIX)
 125     // ### Workaround
 126     if (!res && m_server->serverError() == QAbstractSocket::AddressInUseError)
 127     {
 128         QFile::remove(m_socketName);
 129         res = m_server->listen(m_socketName);
 130     }
 131 #endif
 132     if (!res)
 133         qWarning("QtSingleCoreApplication: listen on local socket failed, %s", qUtf8Printable(m_server->errorString()));
 134
 135     connect(m_server, &QLocalServer::newConnection, this, &QtLocalPeer::receiveConnection);
 136     return false;
 137 }
 138
 139 bool QtLocalPeer::sendMessage(const QString &message, const int timeout)
 140 {
 141     if (!isClient())
 142         return false;
 143
 144     QLocalSocket socket;
 145     bool connOk = false;
 146     for(int i = 0; i < 2; i++)
 147     {
 148         // Try twice, in case the other instance is just starting up
 149         socket.connectToServer(m_socketName);
 150         connOk = socket.waitForConnected(timeout/2);
 151         if (connOk || i)
 152             break;
 153         int ms = 250;
 154 #if defined(Q_OS_WIN)
 155         ::Sleep(DWORD(ms));
 156 #else
 157         struct timespec ts = { ms / 1000, (ms % 1000) * 1000 * 1000 };
 158         ::nanosleep(&ts, nullptr);
 159 #endif
 160     }
 161     if (!connOk)
 162         return false;
 163
 164     QByteArray uMsg(message.toUtf8());
 165     QDataStream ds(&socket);
 166     ds.writeBytes(uMsg.constData(), uMsg.size());
 167     bool res = socket.waitForBytesWritten(timeout);
 168     if (res)
 169     {
 170         res &= socket.waitForReadyRead(timeout);   // wait for ack
 171         if (res)
 172             res &= (socket.read(qstrlen(ACK)) == ACK);
 173     }
 174     return res;
 175 }
 176
 177 void QtLocalPeer::receiveConnection()
 178 {
 179     QLocalSocket *socket = m_server->nextPendingConnection();
 180     if (!socket)
 181         return;
 182
 183     while (true)
 184     {
 185         if (socket->state() == QLocalSocket::UnconnectedState)
 186         {
 187             qWarning("QtLocalPeer: Peer disconnected");
 188             delete socket;
 189             return;
 190         }
 191         if (socket->bytesAvailable() >= qint64(sizeof(quint32)))
 192             break;
 193         socket->waitForReadyRead();
 194     }
 195
 196     QDataStream ds(socket);
 197     QByteArray uMsg;
 198     quint32 remaining;
 199     ds >> remaining;
 200     if (remaining > 65535)
 201     {
 202         // drop suspiciously large data
 203         delete socket;
 204         return;
 205     }
 206
 207     uMsg.resize(remaining);
 208     int got = 0;
 209     char* uMsgBuf = uMsg.data();
 210     do
 211     {
 212         got = ds.readRawData(uMsgBuf, remaining);
 213         remaining -= got;
 214         uMsgBuf += got;
 215     } while (remaining && got >= 0 && socket->waitForReadyRead(2000));
 216     if (got < 0)
 217     {
 218         qWarning("QtLocalPeer: Message reception failed %s", socket->errorString().toLatin1().constData());
 219         delete socket;
 220         return;
 221     }
 222     QString message(QString::fromUtf8(uMsg));
 223     socket->write(ACK, qstrlen(ACK));
 224     socket->waitForBytesWritten(1000);
 225     socket->waitForDisconnected(1000); // make sure client reads ack
 226     delete socket;
 227     emit messageReceived(message); //### (might take a long time to return)
 228 }