SingleApplication

client/3rd/SingleApplication/singleapplication_p.cpp

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+// The MIT License (MIT)
+//
+// Copyright (c) Itay Grudev 2015 - 2020
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+//
+//  W A R N I N G !!!
+//  -----------------
+//
+// This file is not part of the SingleApplication API. It is used purely as an
+// implementation detail. This header file may change from version to
+// version without notice, or may even be removed.
+//
+
+#include <cstdlib>
+#include <cstddef>
+
+#include <QtCore/QDir>
+#include <QtCore/QThread>
+#include <QtCore/QByteArray>
+#include <QtCore/QDataStream>
+#include <QtCore/QElapsedTimer>
+#include <QtCore/QCryptographicHash>
+#include <QtNetwork/QLocalServer>
+#include <QtNetwork/QLocalSocket>
+
+#if QT_VERSION >= QT_VERSION_CHECK(5, 10, 0)
+#include <QtCore/QRandomGenerator>
+#else
+#include <QtCore/QDateTime>
+#endif
+
+#include "singleapplication.h"
+#include "singleapplication_p.h"
+
+#ifdef Q_OS_UNIX
+    #include <unistd.h>
+    #include <sys/types.h>
+    #include <pwd.h>
+#endif
+
+#ifdef Q_OS_WIN
+    #ifndef NOMINMAX
+        #define NOMINMAX 1
+    #endif
+    #include <windows.h>
+    #include <lmcons.h>
+#endif
+
+SingleApplicationPrivate::SingleApplicationPrivate( SingleApplication *q_ptr )
+    : q_ptr( q_ptr )
+{
+    server = nullptr;
+    socket = nullptr;
+    memory = nullptr;
+    instanceNumber = 0;
+}
+
+SingleApplicationPrivate::~SingleApplicationPrivate()
+{
+    if( socket != nullptr ){
+        socket->close();
+        delete socket;
+    }
+
+    if( memory != nullptr ){
+        memory->lock();
+        auto *inst = static_cast<InstancesInfo*>(memory->data());
+        if( server != nullptr ){
+            server->close();
+            delete server;
+            inst->primary = false;
+            inst->primaryPid = -1;
+            inst->primaryUser[0] =  '\0';
+            inst->checksum = blockChecksum();
+        }
+        memory->unlock();
+
+        delete memory;
+    }
+}
+
+QString SingleApplicationPrivate::getUsername()
+{
+#ifdef Q_OS_WIN
+      wchar_t username[UNLEN + 1];
+      // Specifies size of the buffer on input
+      DWORD usernameLength = UNLEN + 1;
+      if( GetUserNameW( username, &usernameLength ) )
+          return QString::fromWCharArray( username );
+#if QT_VERSION < QT_VERSION_CHECK(5, 10, 0)
+      return QString::fromLocal8Bit( qgetenv( "USERNAME" ) );
+#else
+      return qEnvironmentVariable( "USERNAME" );
+#endif
+#endif
+#ifdef Q_OS_UNIX
+      QString username;
+      uid_t uid = geteuid();
+      struct passwd *pw = getpwuid( uid );
+      if( pw )
+          username = QString::fromLocal8Bit( pw->pw_name );
+      if ( username.isEmpty() ){
+#if QT_VERSION < QT_VERSION_CHECK(5, 10, 0)
+          username = QString::fromLocal8Bit( qgetenv( "USER" ) );
+#else
+          username = qEnvironmentVariable( "USER" );
+#endif
+      }
+      return username;
+#endif
+}
+
+void SingleApplicationPrivate::genBlockServerName()
+{
+    QCryptographicHash appData( QCryptographicHash::Sha256 );
+    appData.addData( "SingleApplication", 17 );
+    appData.addData( SingleApplication::app_t::applicationName().toUtf8() );
+    appData.addData( SingleApplication::app_t::organizationName().toUtf8() );
+    appData.addData( SingleApplication::app_t::organizationDomain().toUtf8() );
+
+    if ( ! appDataList.isEmpty() )
+        appData.addData( appDataList.join( "" ).toUtf8() );
+
+    if( ! (options & SingleApplication::Mode::ExcludeAppVersion) ){
+        appData.addData( SingleApplication::app_t::applicationVersion().toUtf8() );
+    }
+
+    if( ! (options & SingleApplication::Mode::ExcludeAppPath) ){
+#ifdef Q_OS_WIN
+        appData.addData( SingleApplication::app_t::applicationFilePath().toLower().toUtf8() );
+#else
+        appData.addData( SingleApplication::app_t::applicationFilePath().toUtf8() );
+#endif
+    }
+
+    // User level block requires a user specific data in the hash
+    if( options & SingleApplication::Mode::User ){
+        appData.addData( getUsername().toUtf8() );
+    }
+
+    // Replace the backslash in RFC 2045 Base64 [a-zA-Z0-9+/=] to comply with
+    // server naming requirements.
+    blockServerName = appData.result().toBase64().replace("/", "_");
+}
+
+void SingleApplicationPrivate::initializeMemoryBlock() const
+{
+    auto *inst = static_cast<InstancesInfo*>( memory->data() );
+    inst->primary = false;
+    inst->secondary = 0;
+    inst->primaryPid = -1;
+    inst->primaryUser[0] =  '\0';
+    inst->checksum = blockChecksum();
+}
+
+void SingleApplicationPrivate::startPrimary()
+{
+    // Reset the number of connections
+    auto *inst = static_cast <InstancesInfo*>( memory->data() );
+
+    inst->primary = true;
+    inst->primaryPid = QCoreApplication::applicationPid();
+    qstrncpy( inst->primaryUser, getUsername().toUtf8().data(), sizeof(inst->primaryUser) );
+    inst->checksum = blockChecksum();
+    instanceNumber = 0;
+    // Successful creation means that no main process exists
+    // So we start a QLocalServer to listen for connections
+    QLocalServer::removeServer( blockServerName );
+    server = new QLocalServer();
+
+    // Restrict access to the socket according to the
+    // SingleApplication::Mode::User flag on User level or no restrictions
+    if( options & SingleApplication::Mode::User ){
+        server->setSocketOptions( QLocalServer::UserAccessOption );
+    } else {
+        server->setSocketOptions( QLocalServer::WorldAccessOption );
+    }
+
+    server->listen( blockServerName );
+    QObject::connect(
+        server,
+        &QLocalServer::newConnection,
+        this,
+        &SingleApplicationPrivate::slotConnectionEstablished
+    );
+}
+
+void SingleApplicationPrivate::startSecondary()
+{
+  auto *inst = static_cast <InstancesInfo*>( memory->data() );
+
+  inst->secondary += 1;
+  inst->checksum = blockChecksum();
+  instanceNumber = inst->secondary;
+}
+
+bool SingleApplicationPrivate::connectToPrimary( int msecs, ConnectionType connectionType )
+{
+    QElapsedTimer time;
+    time.start();
+
+    // Connect to the Local Server of the Primary Instance if not already
+    // connected.
+    if( socket == nullptr ){
+        socket = new QLocalSocket();
+    }
+
+    if( socket->state() == QLocalSocket::ConnectedState ) return true;
+
+    if( socket->state() != QLocalSocket::ConnectedState ){
+
+        while( true ){
+            randomSleep();
+
+          if( socket->state() != QLocalSocket::ConnectingState )
+            socket->connectToServer( blockServerName );
+
+          if( socket->state() == QLocalSocket::ConnectingState ){
+              socket->waitForConnected( static_cast<int>(msecs - time.elapsed()) );
+          }
+
+          // If connected break out of the loop
+          if( socket->state() == QLocalSocket::ConnectedState ) break;
+
+          // If elapsed time since start is longer than the method timeout return
+          if( time.elapsed() >= msecs ) return false;
+        }
+    }
+
+    // Initialisation message according to the SingleApplication protocol
+    QByteArray initMsg;
+    QDataStream writeStream(&initMsg, QIODevice::WriteOnly);
+
+#if (QT_VERSION >= QT_VERSION_CHECK(5, 6, 0))
+    writeStream.setVersion(QDataStream::Qt_5_6);
+#endif
+
+    writeStream << blockServerName.toLatin1();
+    writeStream << static_cast<quint8>(connectionType);
+    writeStream << instanceNumber;
+#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
+    quint16 checksum = qChecksum(QByteArray(initMsg, static_cast<quint32>(initMsg.length())));
+#else
+    quint16 checksum = qChecksum(initMsg.constData(), static_cast<quint32>(initMsg.length()));
+#endif
+    writeStream << checksum;
+
+    // The header indicates the message length that follows
+    QByteArray header;
+    QDataStream headerStream(&header, QIODevice::WriteOnly);
+
+#if (QT_VERSION >= QT_VERSION_CHECK(5, 6, 0))
+    headerStream.setVersion(QDataStream::Qt_5_6);
+#endif
+    headerStream << static_cast <quint64>( initMsg.length() );
+
+    socket->write( header );
+    socket->write( initMsg );
+    bool result = socket->waitForBytesWritten( static_cast<int>(msecs - time.elapsed()) );
+    socket->flush();
+    return result;
+}
+
+quint16 SingleApplicationPrivate::blockChecksum() const
+{
+#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
+    quint16 checksum = qChecksum(QByteArray(static_cast<const char*>(memory->constData()), offsetof(InstancesInfo, checksum)));
+#else
+    quint16 checksum = qChecksum(static_cast<const char*>(memory->constData()), offsetof(InstancesInfo, checksum));
+#endif
+    return checksum;
+}
+
+qint64 SingleApplicationPrivate::primaryPid() const
+{
+    qint64 pid;
+
+    memory->lock();
+    auto *inst = static_cast<InstancesInfo*>( memory->data() );
+    pid = inst->primaryPid;
+    memory->unlock();
+
+    return pid;
+}
+
+QString SingleApplicationPrivate::primaryUser() const
+{
+    QByteArray username;
+
+    memory->lock();
+    auto *inst = static_cast<InstancesInfo*>( memory->data() );
+    username = inst->primaryUser;
+    memory->unlock();
+
+    return QString::fromUtf8( username );
+}
+
+/**
+ * @brief Executed when a connection has been made to the LocalServer
+ */
+void SingleApplicationPrivate::slotConnectionEstablished()
+{
+    QLocalSocket *nextConnSocket = server->nextPendingConnection();
+    connectionMap.insert(nextConnSocket, ConnectionInfo());
+
+    QObject::connect(nextConnSocket, &QLocalSocket::aboutToClose,
+        [nextConnSocket, this](){
+            auto &info = connectionMap[nextConnSocket];
+            Q_EMIT this->slotClientConnectionClosed( nextConnSocket, info.instanceId );
+        }
+    );
+
+    QObject::connect(nextConnSocket, &QLocalSocket::disconnected, nextConnSocket, &QLocalSocket::deleteLater);
+
+    QObject::connect(nextConnSocket, &QLocalSocket::destroyed,
+        [nextConnSocket, this](){
+            connectionMap.remove(nextConnSocket);
+        }
+    );
+
+    QObject::connect(nextConnSocket, &QLocalSocket::readyRead,
+        [nextConnSocket, this](){
+            auto &info = connectionMap[nextConnSocket];
+            switch(info.stage){
+            case StageHeader:
+                readInitMessageHeader(nextConnSocket);
+                break;
+            case StageBody:
+                readInitMessageBody(nextConnSocket);
+                break;
+            case StageConnected:
+                Q_EMIT this->slotDataAvailable( nextConnSocket, info.instanceId );
+                break;
+            default:
+                break;
+            };
+        }
+    );
+}
+
+void SingleApplicationPrivate::readInitMessageHeader( QLocalSocket *sock )
+{
+    if (!connectionMap.contains( sock )){
+        return;
+    }
+
+    if( sock->bytesAvailable() < ( qint64 )sizeof( quint64 ) ){
+        return;
+    }
+
+    QDataStream headerStream( sock );
+
+#if (QT_VERSION >= QT_VERSION_CHECK(5, 6, 0))
+    headerStream.setVersion( QDataStream::Qt_5_6 );
+#endif
+
+    // Read the header to know the message length
+    quint64 msgLen = 0;
+    headerStream >> msgLen;
+    ConnectionInfo &info = connectionMap[sock];
+    info.stage = StageBody;
+    info.msgLen = msgLen;
+
+    if ( sock->bytesAvailable() >= (qint64) msgLen ){
+        readInitMessageBody( sock );
+    }
+}
+
+void SingleApplicationPrivate::readInitMessageBody( QLocalSocket *sock )
+{
+    Q_Q(SingleApplication);
+
+    if (!connectionMap.contains( sock )){
+        return;
+    }
+
+    ConnectionInfo &info = connectionMap[sock];
+    if( sock->bytesAvailable() < ( qint64 )info.msgLen ){
+        return;
+    }
+
+    // Read the message body
+    QByteArray msgBytes = sock->read(info.msgLen);
+    QDataStream readStream(msgBytes);
+
+#if (QT_VERSION >= QT_VERSION_CHECK(5, 6, 0))
+    readStream.setVersion( QDataStream::Qt_5_6 );
+#endif
+
+    // server name
+    QByteArray latin1Name;
+    readStream >> latin1Name;
+
+    // connection type
+    ConnectionType connectionType = InvalidConnection;
+    quint8 connTypeVal = InvalidConnection;
+    readStream >> connTypeVal;
+    connectionType = static_cast <ConnectionType>( connTypeVal );
+
+    // instance id
+    quint32 instanceId = 0;
+    readStream >> instanceId;
+
+    // checksum
+    quint16 msgChecksum = 0;
+    readStream >> msgChecksum;
+
+#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
+    const quint16 actualChecksum = qChecksum(QByteArray(msgBytes, static_cast<quint32>(msgBytes.length() - sizeof(quint16))));
+#else
+    const quint16 actualChecksum = qChecksum(msgBytes.constData(), static_cast<quint32>(msgBytes.length() - sizeof(quint16)));
+#endif
+
+    bool isValid = readStream.status() == QDataStream::Ok &&
+                   QLatin1String(latin1Name) == blockServerName &&
+                   msgChecksum == actualChecksum;
+
+    if( !isValid ){
+        sock->close();
+        return;
+    }
+
+    info.instanceId = instanceId;
+    info.stage = StageConnected;
+
+    if( connectionType == NewInstance ||
+        ( connectionType == SecondaryInstance &&
+          options & SingleApplication::Mode::SecondaryNotification ) )
+    {
+        Q_EMIT q->instanceStarted();
+    }
+
+    if (sock->bytesAvailable() > 0){
+        Q_EMIT this->slotDataAvailable( sock, instanceId );
+    }
+}
+
+void SingleApplicationPrivate::slotDataAvailable( QLocalSocket *dataSocket, quint32 instanceId )
+{
+    Q_Q(SingleApplication);
+    Q_EMIT q->receivedMessage( instanceId, dataSocket->readAll() );
+}
+
+void SingleApplicationPrivate::slotClientConnectionClosed( QLocalSocket *closedSocket, quint32 instanceId )
+{
+    if( closedSocket->bytesAvailable() > 0 )
+        Q_EMIT slotDataAvailable( closedSocket, instanceId  );
+}
+
+void SingleApplicationPrivate::randomSleep()
+{
+#if QT_VERSION >= QT_VERSION_CHECK( 5, 10, 0 )
+    QThread::msleep( QRandomGenerator::global()->bounded( 8u, 18u ));
+#else
+    qsrand( QDateTime::currentMSecsSinceEpoch() % std::numeric_limits<uint>::max() );
+    QThread::msleep( 8 + static_cast <unsigned long>( static_cast <float>( qrand() ) / RAND_MAX * 10 ));
+#endif
+}
+
+void SingleApplicationPrivate::addAppData(const QString &data)
+{
+    appDataList.push_back(data);
+}
+
+QStringList SingleApplicationPrivate::appData() const
+{
+    return appDataList;
+}