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 #if defined(Q_OS_UNIX)
  72 #include <sys/types.h>
  73 #include <time.h>
  74 #include <unistd.h>
  75 #endif
  76
  77 #include <QCoreApplication>
  78 #include <QDataStream>
  79 #include <QDir>
  80 #include <QLocalServer>
  81 #include <QLocalSocket>
  82 #include <QRegularExpression>
  83
  84 #include "base/utils/misc.h"
  85
  86 namespace QtLP_Private
  87 {
  88 #include "qtlockedfile.cpp"
  89
  90 #if defined(Q_OS_WIN)
  91 #include "qtlockedfile_win.cpp"
  92 #else
  93 #include "qtlockedfile_unix.cpp"
  94 #endif
  95 }
  96
  97 const char* QtLocalPeer::ack = "ack";
  98
  99 QtLocalPeer::QtLocalPeer(QObject *parent, const QString &appId)
 100     : QObject(parent)
 101     , id(appId)
 102 {
 103     QString prefix = id;
 104     if (id.isEmpty())
 105     {
 106         id = QCoreApplication::applicationFilePath();
 107 #if defined(Q_OS_WIN)
 108         id = id.toLower();
 109 #endif
 110         prefix = id.section(QLatin1Char('/'), -1);
 111     }
 112     prefix.remove(QRegularExpression("[^a-zA-Z]"));
 113     prefix.truncate(6);
 114
 115     QByteArray idc = id.toUtf8();
 116     quint16 idNum = qChecksum(idc.constData(), idc.size());
 117     socketName = QLatin1String("qtsingleapp-") + prefix
 118                  + QLatin1Char('-') + QString::number(idNum, 16);
 119
 120 #if defined(Q_OS_WIN)
 121     DWORD sessionId = 0;
 122     ::ProcessIdToSessionId(GetCurrentProcessId(), &sessionId);
 123     socketName += (QLatin1Char('-') + QString::number(sessionId, 16));
 124 #else
 125     socketName += (QLatin1Char('-') + QString::number(::getuid(), 16));
 126 #endif
 127
 128     server = new QLocalServer(this);
 129     server->setSocketOptions(QLocalServer::UserAccessOption);
 130     QString lockName = QDir(QDir::tempPath()).absolutePath()
 131                        + QLatin1Char('/') + socketName
 132                        + QLatin1String("-lockfile");
 133     lockFile.setFileName(lockName);
 134     lockFile.open(QIODevice::ReadWrite);
 135 }
 136
 137 QtLocalPeer::~QtLocalPeer()
 138 {
 139     if (!isClient())
 140     {
 141         lockFile.unlock();
 142         lockFile.remove();
 143     }
 144 }
 145
 146 bool QtLocalPeer::isClient()
 147 {
 148     if (lockFile.isLocked())
 149         return false;
 150
 151     if (!lockFile.lock(QtLP_Private::QtLockedFile::WriteLock, false))
 152         return true;
 153
 154     bool res = server->listen(socketName);
 155 #if defined(Q_OS_UNIX)
 156     // ### Workaround
 157     if (!res && server->serverError() == QAbstractSocket::AddressInUseError)
 158     {
 159         QFile::remove(QDir::cleanPath(QDir::tempPath())+QLatin1Char('/')+socketName);
 160         res = server->listen(socketName);
 161     }
 162 #endif
 163     if (!res)
 164         qWarning("QtSingleCoreApplication: listen on local socket failed, %s", qPrintable(server->errorString()));
 165     connect(server, &QLocalServer::newConnection, this, &QtLocalPeer::receiveConnection);
 166     return false;
 167 }
 168
 169 bool QtLocalPeer::sendMessage(const QString &message, const int timeout)
 170 {
 171     if (!isClient())
 172         return false;
 173
 174     QLocalSocket socket;
 175     bool connOk = false;
 176     for(int i = 0; i < 2; i++)
 177     {
 178         // Try twice, in case the other instance is just starting up
 179         socket.connectToServer(socketName);
 180         connOk = socket.waitForConnected(timeout/2);
 181         if (connOk || i)
 182             break;
 183         int ms = 250;
 184 #if defined(Q_OS_WIN)
 185         Sleep(DWORD(ms));
 186 #else
 187         struct timespec ts = { ms / 1000, (ms % 1000) * 1000 * 1000 };
 188         nanosleep(&ts, NULL);
 189 #endif
 190     }
 191     if (!connOk)
 192         return false;
 193
 194     QByteArray uMsg(message.toUtf8());
 195     QDataStream ds(&socket);
 196     ds.writeBytes(uMsg.constData(), uMsg.size());
 197     bool res = socket.waitForBytesWritten(timeout);
 198     if (res)
 199     {
 200         res &= socket.waitForReadyRead(timeout);   // wait for ack
 201         if (res)
 202             res &= (socket.read(qstrlen(ack)) == ack);
 203     }
 204     return res;
 205 }
 206
 207 QString QtLocalPeer::applicationId() const
 208 {
 209     return id;
 210 }
 211
 212 void QtLocalPeer::receiveConnection()
 213 {
 214     QLocalSocket* socket = server->nextPendingConnection();
 215     if (!socket)
 216         return;
 217
 218     while (true)
 219     {
 220         if (socket->state() == QLocalSocket::UnconnectedState)
 221         {
 222             qWarning("QtLocalPeer: Peer disconnected");
 223             delete socket;
 224             return;
 225         }
 226         if (socket->bytesAvailable() >= qint64(sizeof(quint32)))
 227             break;
 228         socket->waitForReadyRead();
 229     }
 230
 231     QDataStream ds(socket);
 232     QByteArray uMsg;
 233     quint32 remaining;
 234     ds >> remaining;
 235     if (remaining > 65535)
 236     {
 237         // drop suspiciously large data
 238         delete socket;
 239         return;
 240     }
 241
 242     uMsg.resize(remaining);
 243     int got = 0;
 244     char* uMsgBuf = uMsg.data();
 245     do
 246     {
 247         got = ds.readRawData(uMsgBuf, remaining);
 248         remaining -= got;
 249         uMsgBuf += got;
 250     } while (remaining && got >= 0 && socket->waitForReadyRead(2000));
 251     if (got < 0)
 252     {
 253         qWarning("QtLocalPeer: Message reception failed %s", socket->errorString().toLatin1().constData());
 254         delete socket;
 255         return;
 256     }
 257     QString message(QString::fromUtf8(uMsg));
 258     socket->write(ack, qstrlen(ack));
 259     socket->waitForBytesWritten(1000);
 260     socket->waitForDisconnected(1000); // make sure client reads ack
 261     delete socket;
 262     emit messageReceived(message); //### (might take a long time to return)
 263 }