source: vbox/trunk/src/VBox/Additions/WINNT/VBoxGINA/Helper.cpp@ 39764

/* $Id: Helper.cpp 39759 2012-01-12 11:58:14Z vboxsync $ */
/** @file
 * VBoxGINA - Windows Logon DLL for VirtualBox, Helper Functions.
 */

/*
 * Copyright (C) 2006-2011 Oracle Corporation
 *
 * This file is part of VirtualBox Open Source Edition (OSE), as
 * available from http://www.virtualbox.org. This file is free software;
 * you can redistribute it and/or modify it under the terms of the GNU
 * General Public License (GPL) as published by the Free Software
 * Foundation, in version 2 as it comes in the "COPYING" file of the
 * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
 * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
 */

#include <windows.h>
#include "winwlx.h"
#include "Helper.h"
#include "VBoxGINA.h"

#include <VBox/VBoxGuest.h>
#include <VBox/VMMDev.h>
#include <iprt/string.h>

/* remote session handling */
DWORD g_dwHandleRemoteSessions = 0;

/* the credentials */
wchar_t g_Username[VMMDEV_CREDENTIALS_SZ_SIZE];
wchar_t g_Password[VMMDEV_CREDENTIALS_SZ_SIZE];
wchar_t g_Domain[VMMDEV_CREDENTIALS_SZ_SIZE];


HANDLE getVBoxDriver(void)
{
    static HANDLE sVBoxDriver = INVALID_HANDLE_VALUE;
    if (sVBoxDriver == INVALID_HANDLE_VALUE)
    {
        sVBoxDriver = CreateFile(L"\\\\.\\VBoxGuest", /** @todo use define */
                                 GENERIC_READ | GENERIC_WRITE,
                                 FILE_SHARE_READ | FILE_SHARE_WRITE,
                                 NULL,
                                 OPEN_EXISTING,
                                 FILE_ATTRIBUTE_NORMAL,
                                 NULL);
        if (sVBoxDriver == INVALID_HANDLE_VALUE)
            Log(("VBoxGINA::sVBoxDriver: failed to open VBoxGuest driver, last error = %d\n", GetLastError()));
    }
    return sVBoxDriver;
}

/**
 * Detects whether our process is running in a remote session or not.
 *
 * @return  bool        true if running in a remote session, false if not.
 */
bool isRemoteSession(void)
{
    return (0 != GetSystemMetrics(SM_REMOTESESSION)) ? true : false;
}

/**
 * Loads the global configuration from registry.
 *
 * @return  DWORD       Windows error code.
 */
DWORD loadConfiguration(void)
{
    HKEY hKey;
    /** @todo Add some registry wrapper function(s) as soon as we got more values to retrieve. */
    DWORD dwRet = RegOpenKeyEx(HKEY_LOCAL_MACHINE, L"SOFTWARE\\Oracle\\VirtualBox Guest Additions\\AutoLogon",
                               0L, KEY_QUERY_VALUE, &hKey);
    if (dwRet == ERROR_SUCCESS)
    {
        DWORD dwValue;
        DWORD dwType = REG_DWORD;
        DWORD dwSize = sizeof(DWORD);

        dwRet = RegQueryValueEx(hKey, L"HandleRemoteSessions", NULL, &dwType, (LPBYTE)&dwValue, &dwSize);
        if (   dwRet  == ERROR_SUCCESS
            && dwType == REG_DWORD
            && dwSize == sizeof(DWORD))
        {
            g_dwHandleRemoteSessions = dwValue;
        }
        RegCloseKey(hKey);
    }
    /* Do not report back an error here yet. */
    return ERROR_SUCCESS;
}

/**
 * Determines whether we should handle the current session or not.
 *
 * @return  bool        true if we should handle this session, false if not.
 */
bool handleCurrentSession(void)
{
    /* Load global configuration from registry. */
    DWORD dwRet = loadConfiguration();
    if (ERROR_SUCCESS != dwRet)
        LogRel(("VBoxGINA::handleCurrentSession: Error loading global configuration, error=%ld\n", dwRet));

    bool fHandle = false;
    if (isRemoteSession())
    {
        if (g_dwHandleRemoteSessions) /* Force remote session handling. */
            fHandle = true;
    }
    else /* No remote session. */
        fHandle = true;

    if (!fHandle)
        LogRel(("VBoxGINA::handleCurrentSession: Handling of remote desktop sessions is disabled.\n"));

    return fHandle;
}

void credentialsReset(void)
{
    RT_ZERO(g_Username);
    RT_ZERO(g_Password);
    RT_ZERO(g_Domain);
}

bool credentialsAvailable(void)
{
    if (!handleCurrentSession())
        return false;

    HANDLE vboxDriver = getVBoxDriver();
    if (vboxDriver ==  INVALID_HANDLE_VALUE)
        return false;

    /* query the VMMDev whether there are credentials */
    VMMDevCredentials vmmreqCredentials = {0};
    vmmdevInitRequest((VMMDevRequestHeader*)&vmmreqCredentials, VMMDevReq_QueryCredentials);
    vmmreqCredentials.u32Flags |= VMMDEV_CREDENTIALS_QUERYPRESENCE;
    DWORD cbReturned;
    if (!DeviceIoControl(vboxDriver, VBOXGUEST_IOCTL_VMMREQUEST(sizeof(vmmreqCredentials)), &vmmreqCredentials, sizeof(vmmreqCredentials),
                         &vmmreqCredentials, sizeof(vmmreqCredentials), &cbReturned, NULL))
    {
        Log(("VBoxGINA::credentialsAvailable: error doing IOCTL, last error: %d\n", GetLastError()));
        return false;
    }
    bool fAvailable = ((vmmreqCredentials.u32Flags & VMMDEV_CREDENTIALS_PRESENT) != 0);
    /*Log(("VBoxGINA::credentialsAvailable: fAvailable: %d\n", fAvailable));*/
    return fAvailable;
}

bool credentialsRetrieve(void)
{
    if (!handleCurrentSession())
        return false;

    Log(("VBoxGINA::credentialsRetrieve\n"));

    HANDLE vboxDriver = getVBoxDriver();
    if (vboxDriver == INVALID_HANDLE_VALUE)
        return false;

    /* to be safe, reset the credentials */
    credentialsReset();

    /* query the credentials */
    VMMDevCredentials vmmreqCredentials = {0};
    vmmdevInitRequest((VMMDevRequestHeader*)&vmmreqCredentials, VMMDevReq_QueryCredentials);
    vmmreqCredentials.u32Flags |= VMMDEV_CREDENTIALS_READ;
    vmmreqCredentials.u32Flags |= VMMDEV_CREDENTIALS_CLEAR;
    DWORD cbReturned;
    if (!DeviceIoControl(vboxDriver, VBOXGUEST_IOCTL_VMMREQUEST(sizeof(vmmreqCredentials)), &vmmreqCredentials, sizeof(vmmreqCredentials),
                         &vmmreqCredentials, sizeof(vmmreqCredentials), &cbReturned, NULL))
    {
        Log(("VBoxGINA::credentialsRetrieve: error doing IOCTL, last error: %d\n", GetLastError()));
        return false;
    }
    /* convert from UTF-8 to UTF-16 and store in global variables */
    PRTUTF16 ptr = NULL;
    if (RT_SUCCESS(RTStrToUtf16(vmmreqCredentials.szUserName, &ptr)) && ptr)
    {
        wcscpy(g_Username, ptr);
        RTUtf16Free(ptr);
    }
    ptr = NULL;
    if (RT_SUCCESS(RTStrToUtf16(vmmreqCredentials.szPassword, &ptr)) && ptr)
    {
        wcscpy(g_Password, ptr);
        RTUtf16Free(ptr);
    }
    ptr = NULL;
    if (RT_SUCCESS(RTStrToUtf16(vmmreqCredentials.szDomain, &ptr)) && ptr)
    {
        wcscpy(g_Domain, ptr);
        RTUtf16Free(ptr);
    }
    Log(("VBoxGINA::credentialsRetrieve: returning user '%s', password '%s', domain '%s'\n",
         vmmreqCredentials.szUserName, vmmreqCredentials.szPassword, vmmreqCredentials.szDomain));

    /* Let the release log know that we got something. */
    LogRel(("VBoxGINA: Credentials from host retrieved\n"));

    return true;
}

/* handle of the poller thread */
RTTHREAD gThreadPoller = NIL_RTTHREAD;


/**
 * Poller thread. Checks periodically whether there are credentials.
 */
static DECLCALLBACK(int) credentialsPoller(RTTHREAD ThreadSelf, void *pvUser)
{
    Log(("VBoxGINA::credentialsPoller\n"));

    do
    {
        if (credentialsAvailable())
        {
            Log(("VBoxGINA::credentialsPoller: got credentials, simulating C-A-D\n"));
            /* tell WinLogon to start the attestation process */
            pWlxFuncs->WlxSasNotify(hGinaWlx, WLX_SAS_TYPE_CTRL_ALT_DEL);
            /* time to say goodbye */
            return 0;
        }
        /* wait a bit */
        if (RTThreadUserWait(ThreadSelf, 500) == VINF_SUCCESS)
        {
            Log(("VBoxGINA::credentialsPoller: we were asked to terminate\n"));
            /* we were asked to terminate, do that instantly! */
            return 0;
        }
    }
    while (1);

    return 0;
}

bool credentialsPollerCreate(void)
{
    if (!handleCurrentSession())
        return false;

    Log(("VBoxGINA::credentialsPollerCreate\n"));

    /* don't create more than one of them */
    if (gThreadPoller != NIL_RTTHREAD)
    {
        Log(("VBoxGINA::credentialsPollerCreate: thread already running, returning!\n"));
        return false;
    }

    /* create the poller thread */
    int rc = RTThreadCreate(&gThreadPoller, credentialsPoller, NULL, 0, RTTHREADTYPE_INFREQUENT_POLLER,
                            RTTHREADFLAGS_WAITABLE, "creds");
    if (RT_FAILURE(rc))
    {
        Log(("VBoxGINA::credentialsPollerCreate: failed to create thread, rc = %Rrc\n", rc));
        return false;
    }
    return true;
}

bool credentialsPollerTerminate(void)
{
    Log(("VBoxGINA::credentialsPollerTerminate\n"));

    if (gThreadPoller == NIL_RTTHREAD)
    {
        Log(("VBoxGINA::credentialsPollerTerminate: either thread or exit sem is NULL!\n"));
        return false;
    }
    /* post termination event semaphore */
    int rc = RTThreadUserSignal(gThreadPoller);
    if (RT_SUCCESS(rc))
    {
        Log(("VBoxGINA::credentialsPollerTerminate: waiting for thread to terminate\n"));
        /* wait until the thread has terminated */
        rc = RTThreadWait(gThreadPoller, RT_INDEFINITE_WAIT, NULL);
        Log(("VBoxGINA::credentialsPollerTermiante: thread has (probably) terminated (rc = %Rrc)\n", rc));
    }
    else
    {
        /* failed to signal the thread - very unlikely - so no point in waiting long. */
        Log(("VBoxGINA::credentialsPollerTermiante: failed to signal semaphore, rc = %Rrc\n", rc));
        rc = RTThreadWait(gThreadPoller, 100, NULL);
        Log(("VBoxGINA::credentialsPollerTermiante: thread has terminated? wait rc = %Rrc\n", rc));
    }
    /* now cleanup */
    gThreadPoller = NIL_RTTHREAD;
    return true;
}