Assert that adapter is always running when client is registering rings

By attaching to NDIS device instead of creating our own device for I/O,
the adapter is always running before client is able to connect and
register rings. NDIS also won't allow adapter to pause with connected
clients.

Signed-off-by: Simon Rozman <simon@rozman.si>

1 files changed, 2 insertions, 0 deletions

diff --git a/wintun.c b/wintun.c
index 62b2485..0e19ee9 100644
--- a/wintun.c
+++ b/wintun.c
@@ -606,6 +606,8 @@ TunRegisterBuffers(_Inout_ TUN_CTX *Ctx, _Inout_ IRP *Irp)
     if (InterlockedCompareExchangePointer(&Ctx->Device.Owner, Stack->FileObject, NULL) != NULL)
         return STATUS_ALREADY_INITIALIZED;
 
+    ASSERT(InterlockedGet(&Ctx->Flags) & TUN_FLAGS_RUNNING);
+
     TUN_REGISTER_RINGS *Rrb = Irp->AssociatedIrp.SystemBuffer;
     if (Status = STATUS_INVALID_PARAMETER, Stack->Parameters.DeviceIoControl.InputBufferLength != sizeof(*Rrb))
         goto cleanupResetOwner;