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
  33     DPRINT("MsfsRead(DeviceObject %p Irp %p)\n", DeviceObject, Irp);
  34
  35     IoStack = IoGetCurrentIrpStackLocation (Irp);
  36     FileObject = IoStack->FileObject;
  37     Fcb = (PMSFS_FCB)FileObject->FsContext;
  38     Ccb = (PMSFS_CCB)FileObject->FsContext2;
  39
  40     DPRINT("MailslotName: %wZ\n", &Fcb->Name);
  41
  42     /* reading is not permitted on client side */
  43     if (Fcb->ServerCcb != Ccb)
  44     {
  45         Irp->IoStatus.Status = STATUS_ACCESS_DENIED;
  46         Irp->IoStatus.Information = 0;
  47
  48         IoCompleteRequest(Irp, IO_NO_INCREMENT);
  49
  50         return STATUS_ACCESS_DENIED;
  51     }
  52
  53     Length = IoStack->Parameters.Read.Length;
  54     if (Irp->MdlAddress)
  55         Buffer = MmGetSystemAddressForMdl (Irp->MdlAddress);
  56     else
  57         Buffer = Irp->UserBuffer;
  58
  59     Status = KeWaitForSingleObject(&Fcb->MessageEvent,
  60                                    UserRequest,
  61                                    KernelMode,
  62                                    FALSE,
  63                                    &Fcb->TimeOut);
  64     if (NT_SUCCESS(Status))
  65     {
  66         if (Fcb->MessageCount > 0)
  67         {
  68             /* copy current message into buffer */
  69             Message = CONTAINING_RECORD(Fcb->MessageListHead.Flink,
  70                                         MSFS_MESSAGE,
  71                                         MessageListEntry);
  72
  73             memcpy(Buffer, &Message->Buffer, min(Message->Size,Length));
  74             LengthRead = Message->Size;
  75
  76             KeAcquireSpinLock(&Fcb->MessageListLock, &oldIrql);
  77             RemoveHeadList(&Fcb->MessageListHead);
  78             KeReleaseSpinLock(&Fcb->MessageListLock, oldIrql);
  79
  80             ExFreePool(Message);
  81             Fcb->MessageCount--;
  82             if (Fcb->MessageCount == 0)
  83             {
  84                 KeClearEvent(&Fcb->MessageEvent);
  85             }
  86         }
  87         else if (Fcb->TimeOut.QuadPart != 0LL)
  88         {
  89             /* No message found after waiting */
  90             Status = STATUS_IO_TIMEOUT;
  91         }
  92      }
  93
  94     Irp->IoStatus.Status = Status;
  95     Irp->IoStatus.Information = LengthRead;
  96
  97     IoCompleteRequest(Irp, IO_NO_INCREMENT);
  98
  99     return Status;
 100 }
 101
 102
 103 NTSTATUS DEFAULTAPI
 104 MsfsWrite(PDEVICE_OBJECT DeviceObject,
 105           PIRP Irp)
 106 {
 107     PIO_STACK_LOCATION IoStack;
 108     PFILE_OBJECT FileObject;
 109     PMSFS_FCB Fcb;
 110     PMSFS_CCB Ccb;
 111     PMSFS_MESSAGE Message;
 112     KIRQL oldIrql;
 113     ULONG Length;
 114     PVOID Buffer;
 115
 116     DPRINT("MsfsWrite(DeviceObject %p Irp %p)\n", DeviceObject, Irp);
 117
 118     IoStack = IoGetCurrentIrpStackLocation (Irp);
 119     FileObject = IoStack->FileObject;
 120     Fcb = (PMSFS_FCB)FileObject->FsContext;
 121     Ccb = (PMSFS_CCB)FileObject->FsContext2;
 122
 123     DPRINT("MailslotName: %wZ\n", &Fcb->Name);
 124
 125     /* writing is not permitted on server side */
 126     if (Fcb->ServerCcb == Ccb)
 127     {
 128         Irp->IoStatus.Status = STATUS_ACCESS_DENIED;
 129         Irp->IoStatus.Information = 0;
 130
 131         IoCompleteRequest(Irp, IO_NO_INCREMENT);
 132
 133         return STATUS_ACCESS_DENIED;
 134     }
 135
 136     Length = IoStack->Parameters.Write.Length;
 137     if (Irp->MdlAddress)
 138         Buffer = MmGetSystemAddressForMdl (Irp->MdlAddress);
 139     else
 140         Buffer = Irp->UserBuffer;
 141
 142     DPRINT("Length: %lu Message: %s\n", Length, (PUCHAR)Buffer);
 143
 144     /* Allocate new message */
 145     Message = ExAllocatePool(NonPagedPool,
 146                              sizeof(MSFS_MESSAGE) + Length);
 147     if (Message == NULL)
 148     {
 149         Irp->IoStatus.Status = STATUS_NO_MEMORY;
 150         Irp->IoStatus.Information = 0;
 151
 152         IoCompleteRequest(Irp, IO_NO_INCREMENT);
 153
 154         return STATUS_NO_MEMORY;
 155     }
 156
 157     Message->Size = Length;
 158     memcpy(&Message->Buffer, Buffer, Length);
 159
 160     KeAcquireSpinLock(&Fcb->MessageListLock, &oldIrql);
 161     InsertTailList(&Fcb->MessageListHead, &Message->MessageListEntry);
 162     KeReleaseSpinLock(&Fcb->MessageListLock, oldIrql);
 163
 164     Fcb->MessageCount++;
 165     if (Fcb->MessageCount == 1)
 166     {
 167         KeSetEvent(&Fcb->MessageEvent,
 168                    0,
 169                    FALSE);
 170     }
 171
 172     Irp->IoStatus.Status = STATUS_SUCCESS;
 173     Irp->IoStatus.Information = Length;
 174
 175     IoCompleteRequest(Irp, IO_NO_INCREMENT);
 176
 177     return STATUS_SUCCESS;
 178 }
 179
 180 /* EOF */