reactos/drivers/filesystems/msfs/rw.c

   1 /*
   2  * COPYRIGHT:  See COPYING in the top level directory
   3  * PROJECT:    ReactOS kernel
   4  * FILE:       drivers/filesystems/msfs/rw.c
   5  * PURPOSE:    Mailslot filesystem
   6  * PROGRAMMER: Eric Kohl
   7  */
   8
   9 /* INCLUDES ******************************************************************/
  10
  11 #include "msfs.h"
  12
  13 #define NDEBUG
  14 #include <debug.h>
  15
  16 /* FUNCTIONS *****************************************************************/
  17
  18 NTSTATUS DEFAULTAPI
  19 MsfsRead(PDEVICE_OBJECT DeviceObject,
  20          PIRP Irp)
  21 {
  22     PIO_STACK_LOCATION IoStack;
  23     PFILE_OBJECT FileObject;
  24     PMSFS_FCB Fcb;
  25     PMSFS_CCB Ccb;
  26     PMSFS_MESSAGE Message;
  27     KIRQL oldIrql;
  28     ULONG Length;
  29     ULONG LengthRead = 0;
  30     PVOID Buffer;
  31     NTSTATUS Status;
  32     PLARGE_INTEGER Timeout;
  33
  34     DPRINT("MsfsRead(DeviceObject %p Irp %p)\n", DeviceObject, Irp);
  35
  36     IoStack = IoGetCurrentIrpStackLocation (Irp);
  37     FileObject = IoStack->FileObject;
  38     Fcb = (PMSFS_FCB)FileObject->FsContext;
  39     Ccb = (PMSFS_CCB)FileObject->FsContext2;
  40
  41     DPRINT("MailslotName: %wZ\n", &Fcb->Name);
  42
  43     /* reading is not permitted on client side */
  44     if (Fcb->ServerCcb != Ccb)
  45     {
  46         Irp->IoStatus.Status = STATUS_ACCESS_DENIED;
  47         Irp->IoStatus.Information = 0;
  48
  49         IoCompleteRequest(Irp, IO_NO_INCREMENT);
  50
  51         return STATUS_ACCESS_DENIED;
  52     }
  53
  54     Length = IoStack->Parameters.Read.Length;
  55     if (Irp->MdlAddress)
  56         Buffer = MmGetSystemAddressForMdlSafe(Irp->MdlAddress, NormalPagePriority);
  57     else
  58         Buffer = Irp->UserBuffer;
  59
  60     if (Fcb->TimeOut.QuadPart == -1LL)
  61         Timeout = NULL;
  62     else
  63         Timeout = &Fcb->TimeOut;
  64
  65     Status = KeWaitForSingleObject(&Fcb->MessageEvent,
  66                                    UserRequest,
  67                                    UserMode,
  68                                    FALSE,
  69                                    Timeout);
  70     if (Status != STATUS_USER_APC)
  71     {
  72         if (Fcb->MessageCount > 0)
  73         {
  74             /* copy current message into buffer */
  75             Message = CONTAINING_RECORD(Fcb->MessageListHead.Flink,
  76                                         MSFS_MESSAGE,
  77                                         MessageListEntry);
  78
  79             memcpy(Buffer, &Message->Buffer, min(Message->Size,Length));
  80             LengthRead = Message->Size;
  81
  82             KeAcquireSpinLock(&Fcb->MessageListLock, &oldIrql);
  83             RemoveHeadList(&Fcb->MessageListHead);
  84             KeReleaseSpinLock(&Fcb->MessageListLock, oldIrql);
  85
  86             ExFreePoolWithTag(Message, 'rFsM');
  87             Fcb->MessageCount--;
  88             if (Fcb->MessageCount == 0)
  89             {
  90                 KeClearEvent(&Fcb->MessageEvent);
  91             }
  92         }
  93         else
  94         {
  95             /* No message found after waiting */
  96             Status = STATUS_IO_TIMEOUT;
  97         }
  98      }
  99
 100     Irp->IoStatus.Status = Status;
 101     Irp->IoStatus.Information = LengthRead;
 102
 103     IoCompleteRequest(Irp, IO_NO_INCREMENT);
 104
 105     return Status;
 106 }
 107
 108
 109 NTSTATUS DEFAULTAPI
 110 MsfsWrite(PDEVICE_OBJECT DeviceObject,
 111           PIRP Irp)
 112 {
 113     PIO_STACK_LOCATION IoStack;
 114     PFILE_OBJECT FileObject;
 115     PMSFS_FCB Fcb;
 116     PMSFS_CCB Ccb;
 117     PMSFS_MESSAGE Message;
 118     KIRQL oldIrql;
 119     ULONG Length;
 120     PVOID Buffer;
 121
 122     DPRINT("MsfsWrite(DeviceObject %p Irp %p)\n", DeviceObject, Irp);
 123
 124     IoStack = IoGetCurrentIrpStackLocation (Irp);
 125     FileObject = IoStack->FileObject;
 126     Fcb = (PMSFS_FCB)FileObject->FsContext;
 127     Ccb = (PMSFS_CCB)FileObject->FsContext2;
 128
 129     DPRINT("MailslotName: %wZ\n", &Fcb->Name);
 130
 131     /* writing is not permitted on server side */
 132     if (Fcb->ServerCcb == Ccb)
 133     {
 134         Irp->IoStatus.Status = STATUS_ACCESS_DENIED;
 135         Irp->IoStatus.Information = 0;
 136
 137         IoCompleteRequest(Irp, IO_NO_INCREMENT);
 138
 139         return STATUS_ACCESS_DENIED;
 140     }
 141
 142     Length = IoStack->Parameters.Write.Length;
 143     if (Irp->MdlAddress)
 144         Buffer = MmGetSystemAddressForMdlSafe(Irp->MdlAddress, NormalPagePriority);
 145     else
 146         Buffer = Irp->UserBuffer;
 147
 148     DPRINT("Length: %lu Message: %s\n", Length, (PUCHAR)Buffer);
 149
 150     /* Allocate new message */
 151     Message = ExAllocatePoolWithTag(NonPagedPool,
 152                                     sizeof(MSFS_MESSAGE) + Length,
 153                                     'rFsM');
 154     if (Message == NULL)
 155     {
 156         Irp->IoStatus.Status = STATUS_NO_MEMORY;
 157         Irp->IoStatus.Information = 0;
 158
 159         IoCompleteRequest(Irp, IO_NO_INCREMENT);
 160
 161         return STATUS_NO_MEMORY;
 162     }
 163
 164     Message->Size = Length;
 165     memcpy(&Message->Buffer, Buffer, Length);
 166
 167     KeAcquireSpinLock(&Fcb->MessageListLock, &oldIrql);
 168     InsertTailList(&Fcb->MessageListHead, &Message->MessageListEntry);
 169     KeReleaseSpinLock(&Fcb->MessageListLock, oldIrql);
 170
 171     Fcb->MessageCount++;
 172     if (Fcb->MessageCount == 1)
 173     {
 174         KeSetEvent(&Fcb->MessageEvent,
 175                    0,
 176                    FALSE);
 177     }
 178
 179     Irp->IoStatus.Status = STATUS_SUCCESS;
 180     Irp->IoStatus.Information = Length;
 181
 182     IoCompleteRequest(Irp, IO_NO_INCREMENT);
 183
 184     return STATUS_SUCCESS;
 185 }
 186
 187 /* EOF */