From 28f99b237bdbfa7792137ca307b3194691609c73 Mon Sep 17 00:00:00 2001
From: Fredrik Orderud <fredrik.orderud@gehealthcare.com>
Date: Thu, 26 Sep 2024 12:33:08 +0200
Subject: [PATCH] [FwUpdateCfu] Fix broken PID/VID filtering in
 FwUpdateCfu::GetVersion method

Fixes #63. I'm struggling to get FwUpdateCfu.exe version protocolCfgExample.cfg to work against the CfuVirtualHid driver in this repo.

The main problem appear to be faulty VID/PID filtering in the FwUpdateCfu::GetVersion method where the method looks for either a VID_xxxx&PID_yyyy or VID_xxxx substring in the DevicePath. The observed DevicePath for CfuVirtualHid on my test machine is \\?\HID#HID_DEVICE_SYSTEM_VHF#2&b84b253&0&0000#{4d1e55b2-f16f-11cf-88cb-001111000030}, which doesn't contain the VID or PID.

The VID/PID filtering mechanism therefore appear to be flawed to me. I think the VID/PID filtering should instead be performed against a HIDD_ATTRIBUTES struct obtained through HidD_GetAttributes after opening the device.
---
 .../FwUpdate.cpp                              | 49 +++++++++----------
 1 file changed, 23 insertions(+), 26 deletions(-)

diff --git a/Tools/ComponentFirmwareUpdateStandAloneToolSample/FwUpdate.cpp b/Tools/ComponentFirmwareUpdateStandAloneToolSample/FwUpdate.cpp
index abb533a..0a156b3 100644
--- a/Tools/ComponentFirmwareUpdateStandAloneToolSample/FwUpdate.cpp
+++ b/Tools/ComponentFirmwareUpdateStandAloneToolSample/FwUpdate.cpp
@@ -182,18 +182,32 @@ Return Value:
     NTSTATUS   status;
     HRESULT    hr = S_OK;
     device.hDevice = INVALID_HANDLE_VALUE;
-    
-    // Check that the VID/PID matches.
-    wchar_t vidPidFilterString[256] = { 0 };
-    memset(&VerReport, 0, sizeof(VerReport));
+    HIDD_ATTRIBUTES attr = { 0 };
 
+    // Open a handle to the device.
+    device.hDevice = CreateFileW(
+        DevicePath,
+        GENERIC_READ,
+        FILE_SHARE_READ | FILE_SHARE_WRITE,
+        NULL,
+        OPEN_EXISTING,
+        FILE_ATTRIBUTE_NORMAL,
+        NULL);
+    if (device.hDevice == INVALID_HANDLE_VALUE)
+    {
+        wprintf(L"INVALID_HANDLE_VALUE %s", DevicePath);
+        hr = HRESULT_FROM_WIN32(GetLastError());
+        goto Exit;
+    }
 
+    if (!HidD_GetAttributes(device.hDevice, &attr)) {
+        hr = HRESULT_FROM_WIN32(GetLastError());
+        goto Exit;
+    }
     // Filter on both if both set
-    if (ProtocolSettings.Vid && ProtocolSettings.Pid) 
+    if (ProtocolSettings.Vid && ProtocolSettings.Pid)
     {
-        swprintf(vidPidFilterString, 256, L"VID_%04X&PID_%04X", 
-                 ProtocolSettings.Vid, ProtocolSettings.Pid);
-        if (!wcsstr(DevicePath, vidPidFilterString))
+        if ((attr.VendorID != ProtocolSettings.Vid) || (attr.ProductID != ProtocolSettings.Pid))
         {
             // The device found doesn't match the vid and pid
             //wprintf(L"The device found does not match the VID/PID\n");
@@ -205,8 +219,7 @@ Return Value:
     // Filter on vid only (vid is mandatory)
     else
     {
-        swprintf(vidPidFilterString, 256, L"VID_%04X", ProtocolSettings.Vid);
-        if (!wcsstr(DevicePath, vidPidFilterString))
+        if (attr.VendorID != ProtocolSettings.Vid)
         {
             // The device found doesn't match the vid
             hr = HRESULT_FROM_WIN32(ERROR_NOT_FOUND);
@@ -214,22 +227,6 @@ Return Value:
         }
     }
 
-    // Open a handle to the device.
-    device.hDevice = CreateFileW(
-        DevicePath,
-        GENERIC_READ,
-        FILE_SHARE_READ | FILE_SHARE_WRITE,
-        NULL,
-        OPEN_EXISTING,
-        FILE_ATTRIBUTE_NORMAL,
-        NULL);
-    if (device.hDevice == INVALID_HANDLE_VALUE)
-    {
-        wprintf(L"INVALID_HANDLE_VALUE %s", DevicePath);
-        hr = HRESULT_FROM_WIN32(GetLastError());
-        goto Exit;
-    }
-
     // Try to get the device's preparsed HID data.
     if (!HidD_GetPreparsedData(device.hDevice, &device.PreparsedData))
     {