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"\\??\\Z:" );
  92   IoCreateSymbolicLink( &LinkName, &DeviceName );
  93
  94   RtlInitUnicodeString( &LinkName, L"\\Device\\Floppy0\\ramdisk.bz2" );
  95   InitializeObjectAttributes( &objattr,
  96                               &LinkName,
  97                               0,
  98                               0,
  99                               0 );
 100   allocsize.u.LowPart = allocsize.u.HighPart = 0;
 101
 102   Status = NtOpenFile( &file,
 103                          GENERIC_READ,
 104                          &objattr,
 105                          &iosb,
 106                          FILE_SHARE_READ,
 107                          FILE_NO_INTERMEDIATE_BUFFERING );
 108
 109   if( !NT_SUCCESS( Status ) )
 110     {
 111       DPRINT( "Failed to open floppy\n" );
 112       goto cleanbuffer;
 113     }
 114
 115   InitializeObjectAttributes( &objattr,
 116                               0,
 117                               0,
 118                               0,
 119                               0 );
 120   Status = NtCreateEvent( &event,
 121                           0,
 122                           &objattr,
 123                           TRUE,
 124                           FALSE );
 125   if( !NT_SUCCESS( Status ) )
 126     {
 127       DPRINT( "Failed to create event\n" );
 128       goto cleanfile;
 129     }
 130
 131   Status = NtQueryInformationFile( file,
 132                                    &iosb,
 133                                    &finfo,
 134                                    sizeof( finfo ),
 135                                    FileStandardInformation );
 136
 137   if( !NT_SUCCESS( Status ) )
 138     {
 139       DPRINT1( "Failed to query file information\n" );
 140       goto cleanevent;
 141     }
 142   tbuff = ExAllocatePool( PagedPool, finfo.EndOfFile.u.LowPart );
 143   if( !tbuff )
 144     {
 145       DPRINT1( "Failed to allocate buffer of size %d\n", finfo.EndOfFile.u.LowPart );
 146       Status = STATUS_INSUFFICIENT_RESOURCES;
 147       goto cleanevent;
 148     }
 149
 150   Status = NtReadFile( file,
 151                        event,
 152                        0,
 153                        0,
 154                        &iosb,
 155                        tbuff,
 156                        finfo.EndOfFile.u.LowPart,
 157                        &allocsize,
 158                        0 );
 159
 160   if( !NT_SUCCESS( Status ) )
 161     {
 162       DPRINT( "Failed to read floppy\n" );
 163       goto cleantbuff;
 164     }
 165   Status = NtWaitForSingleObject( event, FALSE, 0 );
 166   if( Status != STATUS_WAIT_0 || !NT_SUCCESS( iosb.Status ) )
 167     {
 168       DPRINT( "Failed to read floppy\n" );
 169       goto cleantbuff;
 170     }
 171   DPRINT( "RAMDRV: Read in %d bytes, decompressing now\n", iosb.Information );
 172   err = BZ2_bzBuffToBuffDecompress( devext->Buffer,
 173                                     &dstlen,
 174                                     tbuff,
 175                                     iosb.Information,
 176                                     1,
 177                                     0 );
 178   if( err == 0 )
 179     DPRINT( "RAMDRV: Image Decompressed\n");
 180   else DbgPrint( "RAMDRV: Failed to decomparess image, error: %d\n", err );
 181   ExFreePool( tbuff );
 182   NtClose( file );
 183   NtClose( event );
 184   return STATUS_SUCCESS;
 185
 186  cleantbuff:
 187   ExFreePool( tbuff );
 188  cleanevent:
 189   NtClose( event );
 190  cleanfile:
 191   NtClose( file );
 192  cleanbuffer:
 193   ExFreePool( devext->Buffer );
 194
 195  cleandevice:
 196   IoDeleteDevice( DeviceObject );
 197   for(;;);
 198
 199   return Status;
 200 }
 201