reactos/drivers/dd/ramdrv/ramdrv.c

   1 #include <ntddk.h>
   2 #include "ramdrv.h"
   3 #include <debug.h>
   4 #include "../../../lib/bzip2/bzlib.h"
   5
   6 NTSTATUS STDCALL RamdrvDispatchReadWrite(PDEVICE_OBJECT DeviceObject,
   7                                          PIRP Irp)
   8 {
   9   PRAMDRV_DEVICE_EXTENSION devext = (PRAMDRV_DEVICE_EXTENSION)DeviceObject->DeviceExtension;
  10   PIO_STACK_LOCATION Stk = IoGetCurrentIrpStackLocation( Irp );
  11
  12   if( Stk->Parameters.Read.ByteOffset.u.HighPart ||
  13       Stk->Parameters.Read.ByteOffset.u.LowPart >= devext->Size )
  14     {
  15       Irp->IoStatus.Status = STATUS_END_OF_FILE;
  16       Irp->IoStatus.Information = 0;
  17       IoCompleteRequest( Irp, 0 );
  18       return STATUS_END_OF_FILE;
  19     }
  20   if( (Stk->Parameters.Read.ByteOffset.u.LowPart + Stk->Parameters.Read.Length) > devext->Size )
  21     Stk->Parameters.Read.Length = devext->Size - Stk->Parameters.Read.ByteOffset.u.LowPart;
  22   if( Stk->MajorFunction == IRP_MJ_READ )
  23     RtlCopyMemory( MmGetSystemAddressForMdl( Irp->MdlAddress ),
  24                    devext->Buffer + Stk->Parameters.Read.ByteOffset.u.LowPart,
  25                    Stk->Parameters.Read.Length );
  26   else RtlCopyMemory( devext->Buffer + Stk->Parameters.Read.ByteOffset.u.LowPart,
  27                       MmGetSystemAddressForMdl( Irp->MdlAddress ),
  28                       Stk->Parameters.Read.Length );
  29   Irp->IoStatus.Status = STATUS_SUCCESS;
  30   Irp->IoStatus.Information = Stk->Parameters.Read.Length;
  31   IoCompleteRequest( Irp, 0 );
  32   return STATUS_SUCCESS;
  33 }
  34
  35 NTSTATUS STDCALL RamdrvDispatchOpenClose(PDEVICE_OBJECT DeviceObject,
  36                                          PIRP Irp)
  37 {
  38    DPRINT("RamdrvDispatchOpenClose\n");
  39    return STATUS_SUCCESS;
  40 }
  41
  42 NTSTATUS STDCALL DriverEntry(IN PDRIVER_OBJECT DriverObject,
  43                              IN PUNICODE_STRING RegistryPath)
  44 {
  45   UNICODE_STRING DeviceName;
  46   NTSTATUS Status;
  47   PDEVICE_OBJECT DeviceObject;
  48   PRAMDRV_DEVICE_EXTENSION devext;
  49   UNICODE_STRING LinkName;
  50   HANDLE file;
  51   OBJECT_ATTRIBUTES objattr;
  52   IO_STATUS_BLOCK iosb;
  53   LARGE_INTEGER allocsize;
  54   HANDLE event;
  55   void *tbuff;
  56   unsigned int dstlen = 1024 * 1440;
  57   FILE_STANDARD_INFORMATION finfo;
  58   DWORD err;
  59
  60   DPRINT("Ramdisk driver\n");
  61
  62   /* Export other driver entry points... */
  63   DriverObject->MajorFunction[IRP_MJ_CREATE] = RamdrvDispatchOpenClose;
  64   DriverObject->MajorFunction[IRP_MJ_CLOSE] = RamdrvDispatchOpenClose;
  65   DriverObject->MajorFunction[IRP_MJ_READ] = RamdrvDispatchReadWrite;
  66   DriverObject->MajorFunction[IRP_MJ_WRITE] = RamdrvDispatchReadWrite;
  67   //   DriverObject->MajorFunction[IRP_MJ_DEVICE_CONTROL] =
  68   //   RamdrvDispatchDeviceControl;
  69
  70
  71   // create device and symbolic link
  72   RtlInitUnicodeString( &DeviceName, L"\\Device\\Ramdisk" );
  73   Status = IoCreateDevice( DriverObject,
  74                            sizeof( RAMDRV_DEVICE_EXTENSION ),
  75                            &DeviceName,
  76                            FILE_DEVICE_DISK,
  77                            0,
  78                            FALSE,
  79                            &DeviceObject );
  80   if( !NT_SUCCESS( Status ) )
  81     return Status;
  82   DeviceObject->Flags |= DO_DIRECT_IO;
  83   devext = (PRAMDRV_DEVICE_EXTENSION)DeviceObject->DeviceExtension;
  84   devext->Size = 1440 * 1024;
  85   devext->Buffer = ExAllocatePool( PagedPool, devext->Size );
  86   if( !devext->Buffer )
  87     {
  88       Status = STATUS_INSUFFICIENT_RESOURCES;
  89       goto cleandevice;
  90     }
  91   RtlInitUnicodeString( &LinkName, L"\\ArcName\\virt(0)disk(0)ram(0)" );
  92   IoAssignArcName( &LinkName, &DeviceName );
  93   RtlInitUnicodeString( &LinkName, L"\\??\\Z:" );
  94   IoCreateSymbolicLink( &LinkName, &DeviceName );
  95
  96   RtlInitUnicodeString( &LinkName, L"\\Device\\Floppy0\\ramdisk.bz2" );
  97   InitializeObjectAttributes( &objattr,
  98                               &LinkName,
  99                               0,
 100                               0,
 101                               0 );
 102   allocsize.u.LowPart = allocsize.u.HighPart = 0;
 103
 104   Status = NtOpenFile( &file,
 105                          GENERIC_READ,
 106                          &objattr,
 107                          &iosb,
 108                          FILE_SHARE_READ,
 109                          FILE_NO_INTERMEDIATE_BUFFERING );
 110
 111   if( !NT_SUCCESS( Status ) )
 112     {
 113       DPRINT( "Failed to open floppy\n" );
 114       goto cleanbuffer;
 115     }
 116
 117   InitializeObjectAttributes( &objattr,
 118                               0,
 119                               0,
 120                               0,
 121                               0 );
 122   Status = NtCreateEvent( &event,
 123                           0,
 124                           &objattr,
 125                           TRUE,
 126                           FALSE );
 127   if( !NT_SUCCESS( Status ) )
 128     {
 129       DPRINT( "Failed to create event\n" );
 130       goto cleanfile;
 131     }
 132
 133   Status = NtQueryInformationFile( file,
 134                                    &iosb,
 135                                    &finfo,
 136                                    sizeof( finfo ),
 137                                    FileStandardInformation );
 138
 139   if( !NT_SUCCESS( Status ) )
 140     {
 141       DPRINT1( "Failed to query file information\n" );
 142       goto cleanevent;
 143     }
 144   tbuff = ExAllocatePool( PagedPool, finfo.EndOfFile.u.LowPart );
 145   if( !tbuff )
 146     {
 147       DPRINT1( "Failed to allocate buffer of size %d\n", finfo.EndOfFile.u.LowPart );
 148       Status = STATUS_INSUFFICIENT_RESOURCES;
 149       goto cleanevent;
 150     }
 151
 152   Status = NtReadFile( file,
 153                        event,
 154                        0,
 155                        0,
 156                        &iosb,
 157                        tbuff,
 158                        finfo.EndOfFile.u.LowPart,
 159                        &allocsize,
 160                        0 );
 161
 162   if( !NT_SUCCESS( Status ) )
 163     {
 164       DPRINT( "Failed to read floppy\n" );
 165       goto cleantbuff;
 166     }
 167   Status = NtWaitForSingleObject( event, FALSE, 0 );
 168   if( Status != STATUS_WAIT_0 || !NT_SUCCESS( iosb.Status ) )
 169     {
 170       DPRINT( "Failed to read floppy\n" );
 171       goto cleantbuff;
 172     }
 173   DPRINT( "RAMDRV: Read in %d bytes, decompressing now\n", iosb.Information );
 174   err = BZ2_bzBuffToBuffDecompress( devext->Buffer,
 175                                     &dstlen,
 176                                     tbuff,
 177                                     iosb.Information,
 178                                     1,
 179                                     0 );
 180   if( err == 0 )
 181     DPRINT( "RAMDRV: Image Decompressed\n");
 182   else DbgPrint( "RAMDRV: Failed to decomparess image, error: %d\n", err );
 183   ExFreePool( tbuff );
 184   NtClose( file );
 185   NtClose( event );
 186   return STATUS_SUCCESS;
 187
 188  cleantbuff:
 189   ExFreePool( tbuff );
 190  cleanevent:
 191   NtClose( event );
 192  cleanfile:
 193   NtClose( file );
 194  cleanbuffer:
 195   ExFreePool( devext->Buffer );
 196
 197  cleandevice:
 198   IoDeleteDevice( DeviceObject );
 199   for(;;);
 200
 201   return Status;
 202 }
 203