More robust way to get a version info

Driver.cpp

@@ -26,6 +26,7 @@
 #include <wdfrequest.h>
 
 #include "bufferpool.h"
+#include "control.h"
 #include "driver.h"
 #include "trace.h"
 #include "peer.h"
@@ -49,13 +50,27 @@ OvpnEvtDriverUnload(_In_ WDFDRIVER driver)
 {
     UNREFERENCED_PARAMETER(driver);
 
+    LOG_ENTER();
+    LOG_EXIT();
+
     TraceLoggingUnregister(g_hOvpnEtwProvider);
 
     // tail call optimization incorrectly eliminates TraceLoggingUnregister() call
     // add __nop() to prevent TCO
     __nop();
 }
 
+EVT_WDF_OBJECT_CONTEXT_CLEANUP OvpnEvtDriverCleanup;
+
+_Use_decl_annotations_
+VOID OvpnEvtDriverCleanup(_In_ WDFOBJECT driver)
+{
+    UNREFERENCED_PARAMETER(driver);
+
+    LOG_ENTER();
+    LOG_EXIT();
+}
+
 EXTERN_C DRIVER_INITIALIZE DriverEntry;
 
 #ifdef ALLOC_PRAGMA
@@ -80,6 +95,7 @@ DriverEntry(_In_ PDRIVER_OBJECT driverObject, _In_ PUNICODE_STRING registryPath)
     WDF_OBJECT_ATTRIBUTES driverAttrs;
     WDF_OBJECT_ATTRIBUTES_INIT(&driverAttrs);
     WDF_OBJECT_ATTRIBUTES_SET_CONTEXT_TYPE(&driverAttrs, OVPN_DRIVER);
+    driverAttrs.EvtCleanupCallback = OvpnEvtDriverCleanup;
 
     WDF_DRIVER_CONFIG driverConfig;
     WDF_DRIVER_CONFIG_INIT(&driverConfig, OvpnEvtDeviceAdd);
@@ -212,26 +228,6 @@ OvpnEvtIoWrite(WDFQUEUE queue, WDFREQUEST request, size_t length)
     ExReleaseSpinLockShared(&device->SpinLock, kiqrl);
 }
 
-NTSTATUS
-OvpnGetVersion(WDFREQUEST request, _Out_ ULONG_PTR* bytesReturned)
-{
-    *bytesReturned = 0;
-
-    NTSTATUS status;
-    POVPN_VERSION version = NULL;
-    GOTO_IF_NOT_NT_SUCCESS(done, status, WdfRequestRetrieveOutputBuffer(request, sizeof(OVPN_VERSION), (PVOID*)&version, NULL));
-
-    version->Major = OVPN_DCO_VERSION_MAJOR;
-    version->Minor = OVPN_DCO_VERSION_MINOR;
-    version->Patch = OVPN_DCO_VERSION_PATCH;
-
-    *bytesReturned = sizeof(OVPN_VERSION);
-
-done:
-    return status;
-}
-
-
 EVT_WDF_IO_QUEUE_IO_DEVICE_CONTROL OvpnEvtIoDeviceControl;
 
 _Use_decl_annotations_
@@ -336,6 +332,16 @@ VOID OvpnEvtDeviceCleanup(WDFOBJECT obj) {
     device->Adapter = WDF_NO_HANDLE;
     ExReleaseSpinLockExclusive(&device->SpinLock, irql);
 
+    // delete control device if there are no devices left
+    POVPN_DRIVER driverCtx = OvpnGetDriverContext(WdfGetDriver());
+    LONG deviceCount = InterlockedDecrement(&driverCtx->DeviceCount);
+    LOG_INFO("Device count", TraceLoggingValue(deviceCount, "deviceCount"));
+    if ((deviceCount == 0) && (driverCtx->ControlDevice != NULL)) {
+        LOG_INFO("Delete control device");
+        WdfObjectDelete(driverCtx->ControlDevice);
+        driverCtx->ControlDevice = NULL;
+    }
+
     LOG_EXIT();
 }
 
@@ -433,6 +439,17 @@ OvpnEvtDeviceAdd(WDFDRIVER wdfDriver, PWDFDEVICE_INIT deviceInit) {
     WDFDEVICE wdfDevice;
     GOTO_IF_NOT_NT_SUCCESS(done, status, WdfDeviceCreate(&deviceInit, &objAttributes, &wdfDevice));
 
+    POVPN_DRIVER driverCtx = OvpnGetDriverContext(WdfGetDriver());
+    InterlockedIncrement(&driverCtx->DeviceCount);
+
+    LOG_INFO("Device count", TraceLoggingValue(driverCtx->DeviceCount, "count"));
+
+    if (driverCtx->DeviceCount == 1)
+    {
+        // create non-exclusive control device to get the version information
+        GOTO_IF_NOT_NT_SUCCESS(done, status, OvpnCreateControlDevice(wdfDriver));
+    }
+
     // this will fail if one device has already been created but that's ok, since
     // openvpn2/3 accesses devices via Device Interface GUID, and symlink is used only by test client.
     LOG_IF_NOT_NT_SUCCESS(WdfDeviceCreateSymbolicLink(wdfDevice, &symLink));

Driver.h

@@ -47,6 +47,8 @@ EVT_WDF_IO_QUEUE_IO_DEVICE_CONTROL OvpnEvtIoDeviceControl;
 typedef struct _OVPN_DRIVER {
     WSK_PROVIDER_NPI WskProviderNpi;
     WSK_REGISTRATION WskRegistration;
+    WDFDEVICE ControlDevice;
+    LONG DeviceCount;
 } OVPN_DRIVER, * POVPN_DRIVER;
 WDF_DECLARE_CONTEXT_TYPE_WITH_NAME(OVPN_DRIVER, OvpnGetDriverContext)
 

PropertySheet.props

@@ -3,8 +3,8 @@
   <ImportGroup Label="PropertySheets" />
   <PropertyGroup Label="UserMacros">
     <OVPN_DCO_VERSION_MAJOR>1</OVPN_DCO_VERSION_MAJOR>
-    <OVPN_DCO_VERSION_MINOR>2</OVPN_DCO_VERSION_MINOR>
-    <OVPN_DCO_VERSION_PATCH>1</OVPN_DCO_VERSION_PATCH>
+    <OVPN_DCO_VERSION_MINOR>3</OVPN_DCO_VERSION_MINOR>
+    <OVPN_DCO_VERSION_PATCH>0</OVPN_DCO_VERSION_PATCH>
   </PropertyGroup>
   <PropertyGroup />
   <ItemDefinitionGroup>

control.cpp

@@ -0,0 +1,128 @@
+/*
+ *  ovpn-dco-win OpenVPN protocol accelerator for Windows
+ *
+ *  Copyright (C) 2024- OpenVPN Inc <[email protected]>
+ *
+ *  Author:	Lev Stipakov <[email protected]>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2
+ *  as published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "control.h"
+#include "Driver.h"
+#include "uapi\ovpn-dco.h"
+#include "trace.h"
+
+_Use_decl_annotations_
+NTSTATUS
+OvpnGetVersion(WDFREQUEST request, ULONG_PTR* bytesReturned)
+{
+    LOG_ENTER();
+
+    *bytesReturned = 0;
+
+    NTSTATUS status;
+    POVPN_VERSION version = NULL;
+    GOTO_IF_NOT_NT_SUCCESS(done, status, WdfRequestRetrieveOutputBuffer(request, sizeof(OVPN_VERSION), (PVOID*)&version, NULL));
+
+    version->Major = OVPN_DCO_VERSION_MAJOR;
+    version->Minor = OVPN_DCO_VERSION_MINOR;
+    version->Patch = OVPN_DCO_VERSION_PATCH;
+
+    LOG_INFO("Version", TraceLoggingValue(version->Major, "Major"), TraceLoggingValue(version->Minor, "Minor"), TraceLoggingValue(version->Patch, "Patch"));
+
+    *bytesReturned = sizeof(OVPN_VERSION);
+
+done:
+    LOG_EXIT();
+
+    return status;
+}
+
+EVT_WDF_IO_QUEUE_IO_DEVICE_CONTROL OvpnEvtControlDeviceIOControl;
+
+VOID
+OvpnEvtControlDeviceIOControl(WDFQUEUE queue, WDFREQUEST request, size_t outputBufferLength, size_t inputBufferLength, ULONG ioControlCode)
+{
+    UNREFERENCED_PARAMETER(queue);
+    UNREFERENCED_PARAMETER(inputBufferLength);
+    UNREFERENCED_PARAMETER(outputBufferLength);
+
+    NTSTATUS status = STATUS_SUCCESS;
+    ULONG_PTR bytesReturned = 0;
+
+    switch (ioControlCode)
+    {
+    case OVPN_IOCTL_GET_VERSION:
+        status = OvpnGetVersion(request, &bytesReturned);
+        break;
+
+    default:
+        status = STATUS_INVALID_DEVICE_REQUEST;
+        break;
+    }
+
+    WdfRequestCompleteWithInformation(request, status, bytesReturned);
+}
+
+NTSTATUS
+OvpnCreateControlDevice(WDFDRIVER wdfDriver)
+{
+    LOG_ENTER();
+
+    DECLARE_CONST_UNICODE_STRING(symLink, L"\\DosDevices\\ovpn-dco-ver"); // this will be used by CreateFile
+    DECLARE_CONST_UNICODE_STRING(deviceName, L"\\Device\\ovpn-dco-ver"); // this is required tp create symlink
+
+    // allocate control device initialization structure
+    PWDFDEVICE_INIT deviceInit = WdfControlDeviceInitAllocate(wdfDriver, &SDDL_DEVOBJ_SYS_ALL_ADM_RWX_WORLD_R_RES_R);
+    if (deviceInit == NULL)
+    {
+        return STATUS_INSUFFICIENT_RESOURCES;
+    }
+
+    // create the control device
+    WDF_OBJECT_ATTRIBUTES deviceAttributes;
+    WDF_OBJECT_ATTRIBUTES_INIT(&deviceAttributes);
+    WDFDEVICE controlDevice;
+    NTSTATUS status;
+
+    GOTO_IF_NOT_NT_SUCCESS(done, status, WdfDeviceInitAssignName(deviceInit, &deviceName));
+    GOTO_IF_NOT_NT_SUCCESS(done, status, WdfDeviceCreate(&deviceInit, &deviceAttributes, &controlDevice));
+
+    POVPN_DRIVER driverCtx = OvpnGetDriverContext(WdfGetDriver());
+    driverCtx->ControlDevice = controlDevice;
+
+    // symlink for control device
+    GOTO_IF_NOT_NT_SUCCESS(done, status, WdfDeviceCreateSymbolicLink(controlDevice, &symLink));
+
+    // queue to handle IO
+    WDF_IO_QUEUE_CONFIG queueConfig;
+    WDF_IO_QUEUE_CONFIG_INIT_DEFAULT_QUEUE(&queueConfig, WdfIoQueueDispatchParallel);
+    queueConfig.EvtIoDeviceControl = OvpnEvtControlDeviceIOControl;
+    WDFQUEUE queue;
+    GOTO_IF_NOT_NT_SUCCESS(done, status, WdfIoQueueCreate(controlDevice, &queueConfig, WDF_NO_OBJECT_ATTRIBUTES, &queue));
+
+    // Complete the control device initialization
+    WdfControlFinishInitializing(controlDevice);
+
+ done:
+    if (deviceInit)
+    {
+        WdfDeviceInitFree(deviceInit);
+    }
+
+    LOG_EXIT();
+
+    return status;
+}

control.h

@@ -0,0 +1,31 @@
+/*
+ *  ovpn-dco-win OpenVPN protocol accelerator for Windows
+ *
+ *  Copyright (C) 2024- OpenVPN Inc <[email protected]>
+ *
+ *  Author:	Lev Stipakov <[email protected]>
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License version 2
+ *  as published by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#pragma once
+
+#include <ntddk.h>
+#include <wdf.h>
+
+NTSTATUS
+OvpnGetVersion(WDFREQUEST request, _Out_ ULONG_PTR* bytesReturned);
+
+NTSTATUS
+OvpnCreateControlDevice(WDFDRIVER wdfDriver);