reactos/drivers/fs/ms/rw.c

   1 /* $Id$
   2  *
   3  * COPYRIGHT:  See COPYING in the top level directory
   4  * PROJECT:    ReactOS kernel
   5  * FILE:       services/fs/ms/rw.c
   6  * PURPOSE:    Mailslot filesystem
   7  * PROGRAMMER: Eric Kohl <ekohl@rz-online.de>
   8  */
   9
  10 /* INCLUDES ******************************************************************/
  11
  12 #include "msfs.h"
  13
  14 #define NDEBUG
  15 #include <debug.h>
  16
  17
  18 /* FUNCTIONS *****************************************************************/
  19
  20 NTSTATUS DEFAULTAPI
  21 MsfsRead(PDEVICE_OBJECT DeviceObject,
  22          PIRP Irp)
  23 {
  24    PIO_STACK_LOCATION IoStack;
  25    PFILE_OBJECT FileObject;
  26    PMSFS_MAILSLOT Mailslot;
  27    PMSFS_FCB Fcb;
  28    PMSFS_MESSAGE Message;
  29    KIRQL oldIrql;
  30    ULONG Length;
  31    ULONG LengthRead = 0;
  32    PVOID Buffer;
  33    NTSTATUS Status;
  34
  35    DPRINT("MsfsRead(DeviceObject %p Irp %p)\n", DeviceObject, Irp);
  36
  37    IoStack = IoGetCurrentIrpStackLocation (Irp);
  38    FileObject = IoStack->FileObject;
  39    Fcb = (PMSFS_FCB)FileObject->FsContext;
  40    Mailslot = Fcb->Mailslot;
  41
  42    DPRINT("MailslotName: %wZ\n", &Mailslot->Name);
  43
  44    /* reading is not permitted on client side */
  45    if (Fcb->Mailslot->ServerFcb != Fcb)
  46      {
  47         Irp->IoStatus.Status = STATUS_ACCESS_DENIED;
  48         Irp->IoStatus.Information = 0;
  49
  50         IoCompleteRequest(Irp, IO_NO_INCREMENT);
  51
  52         return(STATUS_ACCESS_DENIED);
  53      }
  54
  55    Length = IoStack->Parameters.Read.Length;
  56    if (Irp->MdlAddress)
  57      Buffer = MmGetSystemAddressForMdl (Irp->MdlAddress);
  58    else
  59      Buffer = Irp->UserBuffer;
  60
  61    Status = KeWaitForSingleObject(&Mailslot->MessageEvent,
  62                                   UserRequest,
  63                                   KernelMode,
  64                                   FALSE,
  65                                   NULL); /* FIXME: handle timeout */
  66    if ((NT_SUCCESS(Status)) && (Mailslot->MessageCount > 0))
  67      {
  68         /* copy current message into buffer */
  69         Message = CONTAINING_RECORD(Mailslot->MessageListHead.Flink,
  70                                     MSFS_MESSAGE,
  71                                     MessageListEntry);
  72         memcpy(Buffer, &Message->Buffer, min(Message->Size,Length));
  73         LengthRead = Message->Size;
  74
  75         KeAcquireSpinLock(&Mailslot->MessageListLock, &oldIrql);
  76         RemoveHeadList(&Mailslot->MessageListHead);
  77         KeReleaseSpinLock(&Mailslot->MessageListLock, oldIrql);
  78
  79         ExFreePool(Message);
  80         Mailslot->MessageCount--;
  81         if (Mailslot->MessageCount == 0)
  82           {
  83              KeClearEvent(&Mailslot->MessageEvent);
  84           }
  85      }
  86
  87    Irp->IoStatus.Status = Status;
  88    Irp->IoStatus.Information = LengthRead;
  89
  90    IoCompleteRequest(Irp, IO_NO_INCREMENT);
  91
  92    return(Status);
  93 }
  94
  95
  96 NTSTATUS DEFAULTAPI
  97 MsfsWrite(PDEVICE_OBJECT DeviceObject,
  98           PIRP Irp)
  99 {
 100    PIO_STACK_LOCATION IoStack;
 101    PFILE_OBJECT FileObject;
 102    PMSFS_MAILSLOT Mailslot;
 103    PMSFS_FCB Fcb;
 104    PMSFS_MESSAGE Message;
 105    KIRQL oldIrql;
 106    ULONG Length;
 107    PVOID Buffer;
 108
 109    DPRINT("MsfsWrite(DeviceObject %p Irp %p)\n", DeviceObject, Irp);
 110
 111    IoStack = IoGetCurrentIrpStackLocation (Irp);
 112    FileObject = IoStack->FileObject;
 113    Fcb = (PMSFS_FCB)FileObject->FsContext;
 114    Mailslot = Fcb->Mailslot;
 115
 116    DPRINT("MailslotName: %wZ\n", &Mailslot->Name);
 117
 118    /* writing is not permitted on server side */
 119    if (Fcb->Mailslot->ServerFcb == Fcb)
 120      {
 121         Irp->IoStatus.Status = STATUS_ACCESS_DENIED;
 122         Irp->IoStatus.Information = 0;
 123
 124         IoCompleteRequest(Irp, IO_NO_INCREMENT);
 125
 126         return(STATUS_ACCESS_DENIED);
 127      }
 128
 129    Length = IoStack->Parameters.Write.Length;
 130    if (Irp->MdlAddress)
 131      Buffer = MmGetSystemAddressForMdl (Irp->MdlAddress);
 132    else
 133      Buffer = Irp->UserBuffer;
 134
 135    DPRINT("Length: %lu Message: %s\n", Length, (PUCHAR)Buffer);
 136
 137    /* Allocate new message */
 138    Message = ExAllocatePool(NonPagedPool,
 139                             sizeof(MSFS_MESSAGE) + Length);
 140    if (Message == NULL)
 141      {
 142         Irp->IoStatus.Status = STATUS_NO_MEMORY;
 143         Irp->IoStatus.Information = 0;
 144
 145         IoCompleteRequest(Irp, IO_NO_INCREMENT);
 146
 147         return(STATUS_NO_MEMORY);
 148      }
 149
 150    Message->Size = Length;
 151    memcpy(&Message->Buffer, Buffer, Length);
 152
 153    KeAcquireSpinLock(&Mailslot->MessageListLock, &oldIrql);
 154    InsertTailList(&Mailslot->MessageListHead, &Message->MessageListEntry);
 155    KeReleaseSpinLock(&Mailslot->MessageListLock, oldIrql);
 156
 157    Mailslot->MessageCount++;
 158    if (Mailslot->MessageCount == 1)
 159      {
 160         KeSetEvent(&Mailslot->MessageEvent,
 161                    0,
 162                    FALSE);
 163      }
 164
 165    Irp->IoStatus.Status = STATUS_SUCCESS;
 166    Irp->IoStatus.Information = Length;
 167
 168    IoCompleteRequest(Irp, IO_NO_INCREMENT);
 169
 170    return(STATUS_SUCCESS);
 171 }
 172
 173 /* EOF */