drivers/filesystems/npfs/read.c

   1 /*
   2  * PROJECT:     ReactOS Named Pipe FileSystem
   3  * LICENSE:     BSD - See COPYING.ARM in the top level directory
   4  * FILE:        drivers/filesystems/npfs/read.c
   5  * PURPOSE:     Pipes Reading
   6  * PROGRAMMERS: ReactOS Portable Systems Group
   7  */
   8
   9 /* INCLUDES *******************************************************************/
  10
  11 #include "npfs.h"
  12
  13 // File ID number for NPFS bugchecking support
  14 #define NPFS_BUGCHECK_FILE_ID   (NPFS_BUGCHECK_READ)
  15
  16 /* GLOBALS ********************************************************************/
  17
  18 LONG NpSlowReadCalls;
  19
  20 /* FUNCTIONS ******************************************************************/
  21
  22 BOOLEAN
  23 NTAPI
  24 NpCommonRead(IN PFILE_OBJECT FileObject,
  25              IN PVOID Buffer,
  26              IN ULONG BufferSize,
  27              OUT PIO_STATUS_BLOCK IoStatus,
  28              IN PIRP Irp,
  29              IN PLIST_ENTRY List)
  30 {
  31     NODE_TYPE_CODE NodeType;
  32     PNP_DATA_QUEUE ReadQueue;
  33     PNP_EVENT_BUFFER EventBuffer;
  34     NTSTATUS Status;
  35     ULONG NamedPipeEnd;
  36     PNP_CCB Ccb;
  37     PNP_NONPAGED_CCB NonPagedCcb;
  38     BOOLEAN ReadOk;
  39     PAGED_CODE();
  40
  41     IoStatus->Information = 0;
  42     NodeType = NpDecodeFileObject(FileObject, NULL, &Ccb, &NamedPipeEnd);
  43
  44     if (!NodeType)
  45     {
  46         IoStatus->Status = STATUS_PIPE_DISCONNECTED;
  47         return TRUE;
  48     }
  49
  50     if (NodeType != NPFS_NTC_CCB)
  51     {
  52         IoStatus->Status = STATUS_INVALID_PARAMETER;
  53         return TRUE;
  54     }
  55
  56     NonPagedCcb = Ccb->NonPagedCcb;
  57     ExAcquireResourceExclusiveLite(&NonPagedCcb->Lock, TRUE);
  58
  59     if (Ccb->NamedPipeState == FILE_PIPE_DISCONNECTED_STATE || Ccb->NamedPipeState == FILE_PIPE_LISTENING_STATE)
  60     {
  61         IoStatus->Status = Ccb->NamedPipeState != FILE_PIPE_DISCONNECTED_STATE ? STATUS_PIPE_LISTENING : STATUS_PIPE_DISCONNECTED;
  62         ReadOk = TRUE;
  63         goto Quickie;
  64     }
  65
  66     ASSERT((Ccb->NamedPipeState == FILE_PIPE_CONNECTED_STATE) || (Ccb->NamedPipeState == FILE_PIPE_CLOSING_STATE));
  67
  68     if ((NamedPipeEnd == FILE_PIPE_SERVER_END && Ccb->Fcb->NamedPipeConfiguration == FILE_PIPE_OUTBOUND) ||
  69         (NamedPipeEnd == FILE_PIPE_CLIENT_END && Ccb->Fcb->NamedPipeConfiguration == FILE_PIPE_INBOUND))
  70     {
  71         IoStatus->Status = STATUS_INVALID_PARAMETER;
  72         ReadOk = TRUE;
  73         goto Quickie;
  74     }
  75
  76     if (NamedPipeEnd == FILE_PIPE_SERVER_END)
  77     {
  78         ReadQueue = &Ccb->DataQueue[FILE_PIPE_INBOUND];
  79     }
  80     else
  81     {
  82         ReadQueue = &Ccb->DataQueue[FILE_PIPE_OUTBOUND];
  83     }
  84
  85     EventBuffer = NonPagedCcb->EventBuffer[NamedPipeEnd];
  86
  87     if (ReadQueue->QueueState == WriteEntries)
  88     {
  89         *IoStatus = NpReadDataQueue(ReadQueue,
  90                                     FALSE,
  91                                     FALSE,
  92                                     Buffer,
  93                                     BufferSize,
  94                                     Ccb->ReadMode[NamedPipeEnd],
  95                                     Ccb,
  96                                     List);
  97         if (!NT_SUCCESS(IoStatus->Status))
  98         {
  99             ReadOk = TRUE;
 100             goto Quickie;
 101         }
 102
 103         ReadOk = TRUE;
 104         if (EventBuffer) KeSetEvent(EventBuffer->Event, IO_NO_INCREMENT, FALSE);
 105         goto Quickie;
 106     }
 107
 108     if (Ccb->NamedPipeState == FILE_PIPE_CLOSING_STATE)
 109     {
 110         IoStatus->Status = STATUS_PIPE_BROKEN;
 111         ReadOk = TRUE;
 112         if (EventBuffer) KeSetEvent(EventBuffer->Event, IO_NO_INCREMENT, FALSE);
 113         goto Quickie;
 114     }
 115
 116     if (Ccb->CompletionMode[NamedPipeEnd] == FILE_PIPE_COMPLETE_OPERATION)
 117     {
 118         IoStatus->Status = STATUS_PIPE_EMPTY;
 119         ReadOk = TRUE;
 120         if (EventBuffer) KeSetEvent(EventBuffer->Event, IO_NO_INCREMENT, FALSE);
 121         goto Quickie;
 122     }
 123
 124     if (!Irp)
 125     {
 126         ReadOk = FALSE;
 127         goto Quickie;
 128     }
 129
 130     Status = NpAddDataQueueEntry(NamedPipeEnd,
 131                                  Ccb,
 132                                  ReadQueue,
 133                                  ReadEntries,
 134                                  Buffered,
 135                                  BufferSize,
 136                                  Irp,
 137                                  NULL,
 138                                  0);
 139     IoStatus->Status = Status;
 140     if (!NT_SUCCESS(Status))
 141     {
 142         ReadOk = FALSE;
 143     }
 144     else
 145     {
 146         ReadOk = TRUE;
 147         if (EventBuffer) KeSetEvent(EventBuffer->Event, IO_NO_INCREMENT, FALSE);
 148     }
 149
 150 Quickie:
 151     ExReleaseResourceLite(&Ccb->NonPagedCcb->Lock);
 152     return ReadOk;
 153 }
 154
 155 NTSTATUS
 156 NTAPI
 157 NpFsdRead(IN PDEVICE_OBJECT DeviceObject,
 158           IN PIRP Irp)
 159 {
 160     PIO_STACK_LOCATION IoStack;
 161     IO_STATUS_BLOCK IoStatus;
 162     LIST_ENTRY DeferredList;
 163     PAGED_CODE();
 164     NpSlowReadCalls++;
 165
 166     InitializeListHead(&DeferredList);
 167     IoStack = IoGetCurrentIrpStackLocation(Irp);
 168
 169     FsRtlEnterFileSystem();
 170     NpAcquireSharedVcb();
 171
 172     NpCommonRead(IoStack->FileObject,
 173                  Irp->UserBuffer,
 174                  IoStack->Parameters.Read.Length,
 175                  &IoStatus,
 176                  Irp,
 177                  &DeferredList);
 178
 179     NpReleaseVcb();
 180     NpCompleteDeferredIrps(&DeferredList);
 181     FsRtlExitFileSystem();
 182
 183     if (IoStatus.Status != STATUS_PENDING)
 184     {
 185         Irp->IoStatus.Information = IoStatus.Information;
 186         Irp->IoStatus.Status = IoStatus.Status;
 187         IoCompleteRequest(Irp, IO_NAMED_PIPE_INCREMENT);
 188     }
 189
 190     return IoStatus.Status;
 191 }
 192
 193 /* EOF */