drivers/network/ndisuio/misc.c

   1 /*
   2  * COPYRIGHT:   See COPYING in the top level directory
   3  * PROJECT:     ReactOS NDIS User I/O driver
   4  * FILE:        misc.c
   5  * PURPOSE:     Helper functions
   6  * PROGRAMMERS: Cameron Gutman (cameron.gutman@reactos.org)
   7  */
   8
   9 #include "ndisuio.h"
  10
  11 #define NDEBUG
  12 #include <debug.h>
  13
  14 PNDISUIO_ADAPTER_CONTEXT
  15 FindAdapterContextByName(PNDIS_STRING DeviceName)
  16 {
  17     KIRQL OldIrql;
  18     PLIST_ENTRY CurrentEntry;
  19     PNDISUIO_ADAPTER_CONTEXT AdapterContext;
  20
  21     KeAcquireSpinLock(&GlobalAdapterListLock, &OldIrql);
  22     CurrentEntry = GlobalAdapterList.Flink;
  23     while (CurrentEntry != &GlobalAdapterList)
  24     {
  25         AdapterContext = CONTAINING_RECORD(CurrentEntry, NDISUIO_ADAPTER_CONTEXT, ListEntry);
  26
  27         /* Check if the device name matches */
  28         if (RtlEqualUnicodeString(&AdapterContext->DeviceName, DeviceName, TRUE))
  29         {
  30             KeAcquireSpinLockAtDpcLevel(&AdapterContext->Spinlock);
  31
  32             /* Check that it's not being destroyed */
  33             if (AdapterContext->OpenCount > 0)
  34             {
  35                 KeReleaseSpinLockFromDpcLevel(&AdapterContext->Spinlock);
  36                 KeReleaseSpinLock(&GlobalAdapterListLock, OldIrql);
  37                 return AdapterContext;
  38             }
  39             else
  40             {
  41                 KeReleaseSpinLockFromDpcLevel(&Adaptercontext->Spinlock);
  42             }
  43         }
  44
  45         CurrentEntry = CurrentEntry->Flink;
  46     }
  47     KeReleaseSpinLock(&GlobalAdapterListLock, OldIrql);
  48
  49     return NULL;
  50 }
  51
  52 VOID
  53 ReferenceAdapterContext(PNDISUIO_ADAPTER_CONTEXT AdapterContext, BOOLEAN Locked)
  54 {
  55     KIRQL OldIrql;
  56
  57     /* Lock if needed */
  58     if (!Locked)
  59     {
  60         KeAcquireSpinLock(&AdapterContext->Spinlock, &OldIrql);
  61     }
  62
  63     /* Increment the open count */
  64     AdapterContext->OpenCount++;
  65
  66     /* Unlock if needed */
  67     if (!Locked)
  68     {
  69         KeReleaseSpinLock(&AdapterContext->Spinlock, OldIrql);
  70     }
  71 }
  72
  73 VOID
  74 DereferenceAdapterContextWithOpenEntry(PNDISUIO_ADAPTER_CONTEXT AdapterContext,
  75                                        PNDISUIO_OPEN_ENTRY OpenEntry)
  76 {
  77     KIRQL OldIrql;
  78
  79     /* Lock the adapter context */
  80     KeAcquireSpinLock(&AdapterContext->Spinlock, &OldIrql);
  81
  82     /* Decrement the open count */
  83     AdapterContext->OpenCount--;
  84
  85     /* Cleanup the open entry if we were given one */
  86     if (OpenEntry != NULL)
  87     {
  88         /* Remove the open entry */
  89         RemoveEntryList(&OpenEntry->ListEntry);
  90
  91         /* Invalidate the FO */
  92         OpenEntry->FileObject->FsContext = NULL;
  93         OpenEntry->FileObject->FsContext2 = NULL;
  94
  95         /* Free the open entry */
  96         ExFreePool(OpenEntry);
  97     }
  98
  99     /* See if this binding can be destroyed */
 100     if (AdapterContext->OpenCount == 0)
 101     {
 102         /* Unlock the context */
 103         KeReleaseSpinLock(&AdapterContext->Spinlock, OldIrql);
 104
 105         /* Destroy the adapter context */
 106         UnbindAdapterByContext(AdapterContext);
 107     }
 108     else
 109     {
 110         /* Still more references on it */
 111         KeReleaseSpinLock(&AdapterContext->Spinlock, OldIrql);
 112     }
 113 }