Thread: read raw from the hd

SUPER KOOL! I'll be spending a while looking at that (hopefully); recently I've been discovering that alot more things are open-source that I knew.

To bad, I looked through it this morning, and I see that all it does is look for fragmented files, then tell windows to move the file to a location where it fits whole, so windows ends up grouping all the fragments it's self. So there is no real "raw" reading going on. Defragers are simpler than I thought. Does anyone know how to read/write the FS? Kind of like biosdisk (but without biosdisk).

Give the following sample a try to see if it works..

Code:

#pragma comment( lib, "user32.lib" ) 
#define _WIN32_WINNT 0x0500
#include <windows.h>
#include <stdio.h>
#include <winioctl.h>

int ReadSectors(DISK_GEOMETRY dg, HANDLE hDrive, DWORD dwCylinder, DWORD dwTrack, DWORD dwSector, DWORD dwNumberOfSectors)
{
    DWORD dwCylinders, dwTracksPerCylinder, dwSectorsPerTrack, dwBytesPerSector;
    DWORD dwReadOffset = 0;
    DWORD dwNotUsed;
    char *pSectorData = NULL;
    dwCylinders = dg.Cylinders.QuadPart;
    dwTracksPerCylinder = dg.TracksPerCylinder;
    dwSectorsPerTrack = dg.SectorsPerTrack;
    dwBytesPerSector = dg.BytesPerSector;
    DWORD dwNumberOfBytesToRead = dwBytesPerSector;
    printf("Cylinders: %d\nTracks Per Cylinder: %d\nBytes Per Sector: %d\n\n", dwCylinders, dwTracksPerCylinder, dwBytesPerSector);
    dwNumberOfBytesToRead *= dwNumberOfSectors;
    dwReadOffset = ((dwCylinder * dwTracksPerCylinder + dwTrack) * dwSectorsPerTrack + dwSector) * dwBytesPerSector;
    LARGE_INTEGER liOffset = {dwReadOffset};
    pSectorData = (char*) malloc(dwNumberOfBytesToRead);
    memset(pSectorData, 0, sizeof pSectorData);
    if(dwReadOffset != 0)
    {
        if(!SetFilePointer(hDrive, (liOffset.LowPart), &liOffset.HighPart, FILE_BEGIN))
        {
            printf("SetFilePointer failed\n");
            return -1;
        }
    }   
    if(!ReadFile(hDrive, pSectorData, dwNumberOfBytesToRead, &dwNotUsed, NULL))
    {
        printf("readfile failed\n");
        return -2;
    }
    for(int iIndex = 0; iIndex <= dwNumberOfBytesToRead; iIndex++)
        printf("%02x", pSectorData[iIndex]);
    return 0;
}


int main(void)
{
    int iDiskInputID = 0;
    char cDriveLetter = 'c';
    DISK_GEOMETRY dg;
    DWORD dwNotUsed;
    char cPhysicalDisk[24];
    ZeroMemory(cPhysicalDisk, 24);
    wsprintf(cPhysicalDisk, "\\\\.\\PhysicalDrive%d", iDiskInputID);
    HANDLE hDrive = CreateFile(cPhysicalDisk, GENERIC_READ | GENERIC_WRITE, FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, OPEN_EXISTING, 0, NULL);
    if (!DeviceIoControl(hDrive, IOCTL_DISK_GET_DRIVE_GEOMETRY, NULL, 0, &dg, sizeof(dg), &dwNotUsed, (LPOVERLAPPED)NULL))
    {
        printf("Deviceiocontrol failed\n");
        return -3;
    }
    CloseHandle(hDrive);
    ZeroMemory(cPhysicalDisk, 24);
    wsprintf(cPhysicalDisk, "\\\\.\\%c:", cDriveLetter);
    hDrive = CreateFile(cPhysicalDisk, GENERIC_READ, FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, OPEN_EXISTING, 0, 0);
    return ReadSectors(dg, hDrive, 0 ,0 ,1 ,1);   
}

Thanks.
I'm having some problems with my computer right now so it'll have to wait a bit.