volume.c

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/*
 *  FreeLoader - volume.c
 *
 *  Copyright (C) 2001  Brian Palmer  <brianp@sginet.com>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
 
#include <windows.h>
#include <stdio.h>
#include <tchar.h>
#include "volume.h"
 
static HANDLE    hDiskVolume = NULL;
 
BOOL OpenVolume(LPCTSTR lpszVolumeName)
{
    TCHAR    RealVolumeName[MAX_PATH];
 
    //
    // If they passed in a drive letter (e.g. "A:")
    // then try to open the physical device volume,
    // otherwise we will assume it is a disk image
    // file they are writing to. (not fully supported yet)
    //
    if ((_tcslen(lpszVolumeName) == 2) && (lpszVolumeName[1] == _T(':')))
    {
        _tcscpy(RealVolumeName, _T("\\\\.\\"));
        _tcscat(RealVolumeName, lpszVolumeName);
    }
    else
    {
        _tcscpy(RealVolumeName, lpszVolumeName);
    }
 
    _tprintf(_T("Opening volume \'%s\'\n"), lpszVolumeName);
 
    hDiskVolume = CreateFile(RealVolumeName,
                            GENERIC_READ | GENERIC_WRITE,
                            FILE_SHARE_READ | FILE_SHARE_WRITE,
                            NULL,
                            OPEN_EXISTING,
                            0,
                            NULL);
 
    if (hDiskVolume == INVALID_HANDLE_VALUE)
    {
        _tprintf(_T("%s:%d: "), __FILE__, __LINE__);
        _tprintf(_T("Failed. Error code %ld.\n"), GetLastError());
        return FALSE;
    }
 
    return TRUE;
}
 
void CloseVolume(void)
{
    CloseHandle(hDiskVolume);
}
 
BOOL ReadVolumeSector(ULONG SectorNumber, PVOID SectorBuffer)
{
    DWORD    dwNumberOfBytesRead;
    DWORD    dwFilePosition;
    BOOL    bRetVal;
 
    //
    // FIXME: this doesn't seem to handle the situation
    // properly when SectorNumber is bigger than the
    // amount of sectors on the disk. Seems to me that
    // the call to SetFilePointer() should just give an
    // out of bounds error or something but it doesn't.
    //
    dwFilePosition = SetFilePointer(hDiskVolume, (SectorNumber * 512), NULL, FILE_BEGIN);
    if (dwFilePosition != (SectorNumber * 512))
    {
        _tprintf(_T("%s:%d: "), __FILE__, __LINE__);
        _tprintf(_T("SetFilePointer() failed. Error code %ld.\n"), GetLastError());
        return FALSE;
    }
 
    bRetVal = ReadFile(hDiskVolume, SectorBuffer, 512, &dwNumberOfBytesRead, NULL);
    if (!bRetVal || (dwNumberOfBytesRead != 512))
    {
        _tprintf(_T("%s:%d: "), __FILE__, __LINE__);
        _tprintf(_T("ReadFile() failed. Error code %ld.\n"), GetLastError());
        return FALSE;
    }
 
    return TRUE;
}
 
BOOL WriteVolumeSector(ULONG SectorNumber, PVOID SectorBuffer)
{
    DWORD    dwNumberOfBytesWritten;
    DWORD    dwFilePosition;
    BOOL    bRetVal;
 
    //
    // FIXME: this doesn't seem to handle the situation
    // properly when SectorNumber is bigger than the
    // amount of sectors on the disk. Seems to me that
    // the call to SetFilePointer() should just give an
    // out of bounds error or something but it doesn't.
    //
    dwFilePosition = SetFilePointer(hDiskVolume, (SectorNumber * 512), NULL, FILE_BEGIN);
    if (dwFilePosition != (SectorNumber * 512))
    {
        _tprintf(_T("%s:%d: "), __FILE__, __LINE__);
        _tprintf(_T("SetFilePointer() failed. Error code %ld.\n"), GetLastError());
        return FALSE;
    }
 
    bRetVal = WriteFile(hDiskVolume, SectorBuffer, 512, &dwNumberOfBytesWritten, NULL);
    if (!bRetVal || (dwNumberOfBytesWritten != 512))
    {
        _tprintf(_T("%s:%d: "), __FILE__, __LINE__);
        _tprintf(_T("WriteFile() failed. Error code %ld.\n"), GetLastError());
        return FALSE;
    }
 
    return TRUE;
}