src/qt/winshutdownmonitor.cpp

   1 // Copyright (c) 2014-2016 The Bitcoin Core developers
   2 // Distributed under the MIT software license, see the accompanying
   3 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
   4
   5 #include "winshutdownmonitor.h"
   6
   7 #if defined(Q_OS_WIN) && QT_VERSION >= 0x050000
   8 #include "init.h"
   9 #include "util.h"
  10
  11 #include <windows.h>
  12
  13 #include <QDebug>
  14
  15 #include <openssl/rand.h>
  16
  17 // If we don't want a message to be processed by Qt, return true and set result to
  18 // the value that the window procedure should return. Otherwise return false.
  19 bool WinShutdownMonitor::nativeEventFilter(const QByteArray &eventType, void *pMessage, long *pnResult)
  20 {
  21        Q_UNUSED(eventType);
  22
  23        MSG *pMsg = static_cast<MSG *>(pMessage);
  24
  25        // Seed OpenSSL PRNG with Windows event data (e.g.  mouse movements and other user interactions)
  26        if (RAND_event(pMsg->message, pMsg->wParam, pMsg->lParam) == 0) {
  27             // Warn only once as this is performance-critical
  28             static bool warned = false;
  29             if (!warned) {
  30                 LogPrintf("%s: OpenSSL RAND_event() failed to seed OpenSSL PRNG with enough data.\n", __func__);
  31                 warned = true;
  32             }
  33        }
  34
  35        switch(pMsg->message)
  36        {
  37            case WM_QUERYENDSESSION:
  38            {
  39                // Initiate a client shutdown after receiving a WM_QUERYENDSESSION and block
  40                // Windows session end until we have finished client shutdown.
  41                StartShutdown();
  42                *pnResult = FALSE;
  43                return true;
  44            }
  45
  46            case WM_ENDSESSION:
  47            {
  48                *pnResult = FALSE;
  49                return true;
  50            }
  51        }
  52
  53        return false;
  54 }
  55
  56 void WinShutdownMonitor::registerShutdownBlockReason(const QString& strReason, const HWND& mainWinId)
  57 {
  58     typedef BOOL (WINAPI *PSHUTDOWNBRCREATE)(HWND, LPCWSTR);
  59     PSHUTDOWNBRCREATE shutdownBRCreate = (PSHUTDOWNBRCREATE)GetProcAddress(GetModuleHandleA("User32.dll"), "ShutdownBlockReasonCreate");
  60     if (shutdownBRCreate == nullptr) {
  61         qWarning() << "registerShutdownBlockReason: GetProcAddress for ShutdownBlockReasonCreate failed";
  62         return;
  63     }
  64
  65     if (shutdownBRCreate(mainWinId, strReason.toStdWString().c_str()))
  66         qWarning() << "registerShutdownBlockReason: Successfully registered: " + strReason;
  67     else
  68         qWarning() << "registerShutdownBlockReason: Failed to register: " + strReason;
  69 }
  70 #endif