In Windows environments (XP and Win 7):
What is the best way to automatically have a crash dump generated when processes crash on the system?
Can an installer (MSI) package do this?
One of the best way to have an automatic dump for any/specific process on Windows is to configure a set of entries in the registry. I tried the below on Windows 7 64 bit.
Open notepad.exe, paste the below entry and save it as "EnableDump.reg". You can give any name you wish.
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\Windows Error Reporting\LocalDumps]
"DumpFolder"=hex(2):44,00,3a,00,5c,00,64,00,75,00,6d,00,70,00,00,00
"DumpCount"=dword:00000010
"DumpType"=dword:00000002
"CustomDumpFlags"=dword:00000000
Double click the "EnableDump.reg" and select 'Yes'. I have given the dump folder as 'd:\dump'. You can change it to whatever folder you wish.
Try to execute a crashing application, Windows will display the error dialog. Choose 'Close the Program' option. After that you will see the dump in the configured folder. The name of the dump file will be .exe..dmp.
For more details, you can refer the below link.
http://msdn.microsoft.com/en-us/library/bb787181(VS.85).aspx
Below explanation is based on another answer, but the logic is mine (without attribution need, as said on my profile);
Having your own dump generation framework which automatically creates a process dump when any Unhandled exception is encountered, would avoid clients having to install WinDbg.
At the application start up use SetUnhandledExceptionFilter(...) Win32 API to register a callback (i.e. application level exception-handler).
Now the registered callback function is called whenever there is any exception which is not handled. You may then create the process dump using MiniDumpWriteDump(...) API from DbgHelp.dll.
C++ Sample (unicode-enabled)
header-file
#ifndef CRASH_REPORTER_H
#define CRASH_REPORTER_H
//Exclude rarely used content from the Windows headers.
#ifndef WIN32_LEAN_AND_MEAN
# define WIN32_LEAN_AND_MEAN
# include <windows.h>
# undef WIN32_LEAN_AND_MEAN
#else
# include <windows.h>
#endif
#include <tchar.h>
#include <DbgHelp.h>
class CrashReporter {
public:
inline CrashReporter() { Register(); }
inline ~CrashReporter() { Unregister(); }
inline static void Register() {
if(m_lastExceptionFilter != NULL) {
fprintf(stdout, "CrashReporter: is already registered\n");
fflush(stdout);
}
SetErrorMode(SEM_FAILCRITICALERRORS);
//ensures UnHandledExceptionFilter is called before App dies.
m_lastExceptionFilter = SetUnhandledExceptionFilter(UnHandledExceptionFilter);
}
inline static void Unregister() {
SetUnhandledExceptionFilter(m_lastExceptionFilter);
}
private:
static LPTOP_LEVEL_EXCEPTION_FILTER m_lastExceptionFilter;
static LONG WINAPI UnHandledExceptionFilter(_EXCEPTION_POINTERS *);
};
#endif // CRASH_REPORTER_H
source-file
#include "crash-report.h"
#include <stdio.h>
LPTOP_LEVEL_EXCEPTION_FILTER CrashReporter::m_lastExceptionFilter = NULL;
typedef BOOL (WINAPI *MiniDumpWriteDumpFunc)(HANDLE hProcess, DWORD ProcessId
, HANDLE hFile
, MINIDUMP_TYPE DumpType
, const MINIDUMP_EXCEPTION_INFORMATION *ExceptionInfo
, const MINIDUMP_USER_STREAM_INFORMATION *UserStreamInfo
, const MINIDUMP_CALLBACK_INFORMATION *Callback
);
LONG WINAPI CrashReporter::UnHandledExceptionFilter(struct _EXCEPTION_POINTERS *exceptionPtr)
{
//we load DbgHelp.dll dynamically, to support Windows 2000
HMODULE hModule = ::LoadLibraryA("DbgHelp.dll");
if (hModule) {
MiniDumpWriteDumpFunc dumpFunc = reinterpret_cast<MiniDumpWriteDumpFunc>(
::GetProcAddress(hModule, "MiniDumpWriteDump")
);
if (dumpFunc) {
//fetch system time for dump-file name
SYSTEMTIME SystemTime;
::GetLocalTime(&SystemTime);
//choose proper path for dump-file
wchar_t dumpFilePath[MAX_PATH] = {0};
_snwprintf_s(dumpFilePath, MAX_PATH, L"crash_%04d-%d-%02d_%d-%02d-%02d.dmp"
, SystemTime.wYear, SystemTime.wMonth, SystemTime.wDay
, SystemTime.wHour, SystemTime.wMinute, SystemTime.wSecond
);
//create and open the dump-file
HANDLE hFile = ::CreateFileW( dumpFilePath, GENERIC_WRITE
, FILE_SHARE_WRITE
, NULL
, CREATE_ALWAYS
, FILE_ATTRIBUTE_NORMAL | FILE_ATTRIBUTE_HIDDEN
, NULL
);
if (hFile != INVALID_HANDLE_VALUE) {
_MINIDUMP_EXCEPTION_INFORMATION exceptionInfo;
exceptionInfo.ThreadId = GetCurrentThreadId();
exceptionInfo.ExceptionPointers = exceptionPtr;
exceptionInfo.ClientPointers = NULL;
//at last write crash-dump to file
bool ok = dumpFunc(::GetCurrentProcess(), ::GetCurrentProcessId()
, hFile, MiniDumpNormal
, &exceptionInfo, NULL, NULL
);
//dump-data is written, and we can close the file
CloseHandle(hFile);
if (ok) {
//Return from UnhandledExceptionFilter and execute the associated exception handler.
// This usually results in process termination.
return EXCEPTION_EXECUTE_HANDLER;
}
}
}
}
//Proceed with normal execution of UnhandledExceptionFilter.
// That means obeying the SetErrorMode flags,
// or invoking the Application Error pop-up message box.
return EXCEPTION_CONTINUE_SEARCH;
}
usage
#include "3rdParty/crash-report.h"
int main(int argc, char *argv[])
{
CrashReporter crashReporter;
(void)crashReporter; //prevents unused warnings
// [application main loop should be here]
return 0;
}
Windows XP:
The following steps enable automatic crash dumps:
1) Open a command prompt, running as administrator
2) Run drwtsn32 -i. This will install Doctor Watson as the default debugger when something crashes
3) Click Ok
4) From the command prompt, run drwtsn32
5) Set the Crash Dump path to your favorite directory, or leave the default.
6) Set the Crash Dump Type to mini. Note that under some circumstances, we may ask you for a full crash dump.
7) Make sure the Dump All Thread Contexts and Create Crash Dump File options are selected.
8) Click Ok
9) If a user.dmp file already exists in the Crash Dump path, delete it.
Windows 7: Location is:
C:\Users[Current User when app crashed]\AppData\Local\Microsoft\Windows\WER\ReportArchive
Related
I've been experimenting with Overlapped IO feature of Win32 API, namely ReadFileEx and WriteFileEx functions.
Here is a simplest example:
#include <iostream>
#include <string>
#include <Windows.h>
const DWORD blockSize = 512;
char buffer[blockSize];
bool done = false;
OVERLAPPED overlapped;
void Completion(DWORD error, DWORD read, LPOVERLAPPED overlapped) {
}
int _tmain(int argc, _TCHAR* argv[])
{
std::wstring fileName;
std::wcout << "Enter file name: ";
std::getline(std::wcin, fileName);
HANDLE file = CreateFile(
fileName.c_str(),
GENERIC_READ,
FILE_SHARE_READ,
NULL,
OPEN_EXISTING,
FILE_FLAG_OVERLAPPED,
NULL
);
if (file == INVALID_HANDLE_VALUE) {
std::wcout << "Error while opening file: " << GetLastError() << std::endl;
std::cin.get();
return -1;
}
overlapped.Offset = overlapped.OffsetHigh = 0;
ReadFileEx(file, buffer, blockSize, &overlapped, (LPOVERLAPPED_COMPLETION_ROUTINE) &Completion);
while (!done)
SleepEx(1000, TRUE);
return 0;
}
As you can see, I'm starting overlapped reading with ReadFileEx and waiting for it to finish using SleepEx. Although Completion has empty body and the program should hang forever after reading first block, it does something completely different. In fact, it raises AccessViolation with code 0xC0000005 on the first call to SleepEx. This happens on Windows machines with Win 7 and Win Vista I've tried, including fresh 64 bit virtual machine with Windows 7. But, curiously, it does not fail on one Windows 8.1 machine and runs just as expected. This was compiled with Visual Studio 2010, but I don't think it matters.
I can not understand what have I done wrong, so if anyone knows the answer, please help me.
The callback must be of the following form, as stated clearly in the documentation:
VOID CALLBACK FileIOCompletionRoutine(
_In_ DWORD dwErrorCode,
_In_ DWORD dwNumberOfBytesTransfered,
_Inout_ LPOVERLAPPED lpOverlapped
);
Your function has the wrong calling convention. Your cast does not change that. It is simply a way for you to stop the compiler rejecting your ill-formed program. Don't lie to the compiler. Correct the function declaration by adding the CALLBACK calling convention.
I want to create a loadable DLL of some of my tcl methods. But I am not getting how to do this. For that I have taken a simple example of tcl api which adds two numbers and prints the sum. Now I want to create a loadable DLL for this to export this tcl functionality.
But I am not understanding how to do it in Visual Studio. I have written a C code which can call this tcl api and get the sum of two integers, but again I don't want it to do this way. I want to create a DLL file to use this tcl functionality. How can I create this DLL on Visual Studio 2010.
Below is my sample tcl program that I am using:
#!/usr/bin/env tclsh8.5
proc add_two_nos { } {
set a 10
set b 20
set c [expr { $a + $b } ]
puts " c is $c ......."
}
And here is the C code which can use this tcl functionality :
#include <tcl.h>
#include <stdio.h>
#include <stdlib.h>
int main(int argc, char **argv) {
Tcl_Interp *interp;
int code;
char *result;
Tcl_FindExecutable(argv[0]);
interp = Tcl_CreateInterp();
code = Tcl_Eval(interp, "source myscript.tcl; add_two_nos");
/* Retrieve the result... */
result = Tcl_GetString(Tcl_GetObjResult(interp));
/* Check for error! If an error, message is result. */
if (code == TCL_ERROR) {
fprintf(stderr, "ERROR in script: %s\n", result);
exit(1);
}
/* Print (normal) result if non-empty; we'll skip handling encodings for now */
if (strlen(result)) {
printf("%s\n", result);
}
/* Clean up */
Tcl_DeleteInterp(interp);
exit(0);
}
I have successfully compiled this code with the below command
gcc simple_addition_wrapper_new.c -I/usr/include/tcl8.5/ -ltcl8.5 -o simple_addition_op
The above code is working with the expected output.
What steps do I need to take to create a loadable dll for this in Visual Studio 2010?
If you look at the answers to this question: here it gives the basic outline of the process you need to go through. There are links from my answer to some Microsoft MSDN articles on creating DLLs.
To go into this in a little more detail for a C++ dll that has Tcl embedded in it.
The first step is to create a new visual studio project with the correct type, one that is going to build a dll that exports symbols. My example project is called TclEmbeddedInDll and that name appears in code in symbols such as TCLEMBEDDEDINDLL_API that are generated by Visual Studio.
The dllmain.cpp look like this:
// dllmain.cpp : Defines the entry point for the DLL application.
#include "stdafx.h"
BOOL APIENTRY DllMain( HMODULE hModule,
DWORD ul_reason_for_call,
LPVOID lpReserved
)
{
switch (ul_reason_for_call)
{
case DLL_PROCESS_ATTACH:
{
allocInterp() ;
break ;
}
case DLL_THREAD_ATTACH:
break ;
case DLL_THREAD_DETACH:
break ;
case DLL_PROCESS_DETACH:
{
destroyInterp() ;
break;
}
}
return TRUE;
}
The allocInterp() and destroyInterp() functions are defined in the TclEmbeddedInDll.h, the reason for using functions here rather than creating the Tcl_Interp directly is that it keeps the details about Tcl away from the DLL interface. If you create the interp here then you have to include tcl.h and then things get complicated when you try and use the DLL in another program.
The TclEmbeddedInDll.h and .cpp are shown next, the function fnTclEmbeddedInDll() is the one that is exported from the DLL - I'm using C linkage for this rather than C++ as it makes it easier to call the function from other languages IMHO.
// The following ifdef block is the standard way of creating macros which make exporting
// from a DLL simpler. All files within this DLL are compiled with the TCLEMBEDDEDINDLL_EXPORTS
// symbol defined on the command line. This symbol should not be defined on any project
// that uses this DLL. This way any other project whose source files include this file see
// TCLEMBEDDEDINDLL_API functions as being imported from a DLL, whereas this DLL sees symbols
// defined with this macro as being exported.
#ifdef TCLEMBEDDEDINDLL_EXPORTS
#define TCLEMBEDDEDINDLL_API __declspec(dllexport)
#else
#define TCLEMBEDDEDINDLL_API __declspec(dllimport)
#endif
extern "C" {
TCLEMBEDDEDINDLL_API void fnTclEmbeddedInDll(void);
}
void allocInterp() ;
void destroyInterp() ;
// TclEmbeddedInDll.cpp : Defines the exported functions for the DLL application.
//
#include "stdafx.h"
extern "C" {
static Tcl_Interp *interp ;
// This is an example of an exported function.
TCLEMBEDDEDINDLL_API void fnTclEmbeddedInDll(void)
{
int code;
const char *result;
code = Tcl_Eval(interp, "source simple_addition.tcl; add_two_nos");
result = Tcl_GetString(Tcl_GetObjResult(interp));
}
}
void allocInterp()
{
Tcl_FindExecutable(NULL);
interp = Tcl_CreateInterp();
}
void destroyInterp()
{
Tcl_DeleteInterp(interp);
}
The implementation of allocInterp() and destroyInterp() is very naive, no error checking is done.
Finally for the Dll the stdafx.h file ties it all together like this:
// stdafx.h : include file for standard system include files,
// or project specific include files that are used frequently, but
// are changed infrequently
//
#pragma once
#include "targetver.h"
#define WIN32_LEAN_AND_MEAN // Exclude rarely-used stuff from Windows headers
// Windows Header Files:
#include <windows.h>
// TODO: reference additional headers your program requires here
#include <tcl.h>
#include "TclEmbeddedInDll.h"
I have a 32 bit program that has been installed by a customer on 64 bit windows.
There appears to be a problem with using ShellExecute and the print verb in that configuration. First my test program.
// printme.cpp : Defines the entry point for the console application.
//
#include "stdafx.h"
#include "objbase.h"
#include <windows.h>
#include <shellapi.h>
int main(int argc, char* argv[])
{
if (argc != 2)
{
printf("Usage: %s file_to_print", argv[0]);
return 0;
}
CoInitializeEx(NULL, COINIT_APARTMENTTHREADED) ; //| COINIT_DISABLE_OLE1DDE);
HINSTANCE retVal = ::ShellExecute(NULL, "print", argv[1], NULL, NULL, 0); // don't ask, as the user can always cancel...
printf("RetVal = %08x\n", retVal);
printf("LastError = %08x\n", GetLastError());
return 0;
}
This program works correctly on 32 bit windows version up to Windows 7. The program simply runs the print verb on the first argument passed on the command line.
printme Page1.htm
On the system in question, the registry is set up as follows:
HKEY_CLASSES_ROOT\htmlfile\shell\print\command
contains a default value of type REG_EXPAND_SZ containing
rundll32.exe %windir%\system32\mshtml.dll,PrintHTML "%1"
If I run the following command
rundll32 c:\windows\system32\mshtml.dll,PrintHTML “Page1.htm”
the print dialog is successfully shown.
However running my program blinks, but the print dialog never appears, and a stalled copy of
C:\Windows\sysWow64\rundll32.exe is in process manager, which never completes.
Is there a workaround, or is ShellExecute permanently broken for common verbs on common file types from 32 bit programs on 64 bit windows?
It turns out the problem is the last parameter of ShellExecute. While 0 worked for years, it now requires SW_SHOW to function correctly for the print verb in this case. Perhaps a recent windows update changed the behavior?
I am a beginner for Eclipse. I now have Eclipse C/C++ IDE with OpenCV library running on Windows 7. So far it works after spending hours trying to get it running. But then I realize that Eclipse does not pop up a command prompt as VS2010 does while debugging. And moreover Eclipse's debug mode is just stuck in there and refuse to output anything. But if the code doesn't involve the OpenCV things it works again.
Below is the code I use for testing. It captures images from webcam and output it to the screen. The infinite loop (until you press 'q') makes sure it constantly grabs new inputs from the camera.
I browsed through the workspace and run the exe just compiled and it worked flawlessly. So I don't think there's anything wrong in the code (it's an example code anyway
In brief, can I just pop up a command prompt window in debug mode? And why is Eclipse console stuck when the code involves some OpenCV functions?
#include <stdio.h>
#include <stdlib.h>
#include <tchar.h>
#include <cv.h>
#include <cxcore.h>
#include <highgui.h>
#include <iostream>
int _tmain(int argc, _TCHAR* argv[])
{
CvCapture *capture = 0;
IplImage *frame = 0;
int key = 0;
/* initialize camera */
capture = cvCaptureFromCAM( 0 );
/* always check */
if ( !capture ) {
printf("Cannot open initialize webcam!\n");
return 1;
}
/* create a window for the video */
cvNamedWindow( "result", CV_WINDOW_AUTOSIZE );
while( key != 'q' ) {
/* get a frame */
frame = cvQueryFrame( capture );
/* always check */
if( !frame ) break;
/* display current frame */
cvShowImage( "result", frame );
/* exit if user press 'q' */
key = cvWaitKey( 1 );
}
/* free memory */
cvDestroyWindow( "result" );
cvReleaseCapture( &capture );
return 0;
}
This is because you have already set the windows 7 system variable PATH to your MinGw/bin and compiled opencv bin directories. So when you run the program from your folder your system automatically take the required binaries from its PATH and the program runs correctly.
I don't know why but Eclipse does not take it directly from the system environment PATH variable. So we have to set it ourself.
go to Preferences > C/C++ (Expand it) > Environment > Add:
"Name:PATH"
"Value:C:\MinGW\bin;C:\opencv_MinGW\bin"
where opencv_MinGW is the folder where I compiled my opencv
SysInternals's WinObj can list all device objects.
I wonder how it can list the devices.
Is there any open source we can read?(or a code snippet)
What is the most significant function I should know?
WinObj uses the NT system calls NtOpenDirectoryObject and NtQueryDirectoryObject. There is no driver or kernel code needed. You won't see the imports because these NT functions are loaded via LoadLibrary/GetProcAddress.
You don't have to enumerate the entire object namespace. If you're interested in the device objects call NtOpenDirectoryObject with "\Device", then call NtQueryDirectoryObject on the returned handle.
According to SysInternals' web page:
The native NT API provides routines
that allow user-mode programs to
browse the namespace and query the
status of objects located there, but
the interfaces are undocumented.
I've tried looking at WinObj's import table (dumpbin /imports winobj.exe) but there are no obvious suspects :-(
As per the answer from user1575778 you can use NtOpenDirectoryObject and NtQueryDirectoryObject (which from user mode are identical to ZwOpenDirectoryObject and ZwQueryDirectoryObject respectively) to list the objects inside the object manager namespace.
Have a look at objmgr.hpp of NT Objects aka ntobjx, in particular at the class NtObjMgr::Directory (or DirectoryT). It provides the same functionality nicely wrapped into a C++ class. The whole utility is open source under a liberal license (dual-licensed due to WTL-use: MIT and MS-PL), so bits and pieces can be reused however you please, provided you comply with the license terms.
But here's a simple C++ code example catering just your use case:
#include <Windows.h>
#include <tchar.h>
#include <cstdio>
#include <winternl.h>
NTSTATUS (NTAPI* NtOpenDirectoryObject)(PHANDLE, ACCESS_MASK, POBJECT_ATTRIBUTES);
NTSTATUS (NTAPI* NtQueryDirectoryObject)(HANDLE, PVOID, ULONG, BOOLEAN, BOOLEAN, PULONG, PULONG);
VOID (NTAPI* RtlInitUnicodeString_)(PUNICODE_STRING, PCWSTR);
NTSTATUS (NTAPI* NtClose_)(HANDLE);
#define DIRECTORY_QUERY (0x0001)
#define DIRECTORY_TRAVERSE (0x0002)
typedef struct _OBJECT_DIRECTORY_INFORMATION {
UNICODE_STRING Name;
UNICODE_STRING TypeName;
} OBJECT_DIRECTORY_INFORMATION, *POBJECT_DIRECTORY_INFORMATION;
#ifndef STATUS_SUCCESS
#define STATUS_SUCCESS ((NTSTATUS)0x00000000L) // ntsubauth
#endif // STATUS_SUCCESS
#ifndef STATUS_MORE_ENTRIES
#define STATUS_MORE_ENTRIES ((NTSTATUS)0x00000105L)
#endif // STATUS_MORE_ENTRIES
#ifndef STATUS_NO_MORE_ENTRIES
#define STATUS_NO_MORE_ENTRIES ((NTSTATUS)0x8000001AL)
#endif // STATUS_NO_MORE_ENTRIES
int PrintDevices()
{
NTSTATUS ntStatus;
OBJECT_ATTRIBUTES oa;
UNICODE_STRING objname;
HANDLE hDeviceDir = NULL;
RtlInitUnicodeString_(&objname, L"\\Device");
InitializeObjectAttributes(&oa, &objname, 0, NULL, NULL);
ntStatus = NtOpenDirectoryObject(&hDeviceDir, DIRECTORY_QUERY | DIRECTORY_TRAVERSE, &oa);
if(NT_SUCCESS(ntStatus))
{
size_t const bufSize = 0x10000;
BYTE buf[bufSize] = {0};
ULONG start = 0, idx = 0, bytes;
BOOLEAN restart = TRUE;
for(;;)
{
ntStatus = NtQueryDirectoryObject(hDeviceDir, PBYTE(buf), bufSize, FALSE, restart, &idx, &bytes);
if(NT_SUCCESS(ntStatus))
{
POBJECT_DIRECTORY_INFORMATION const pdilist = reinterpret_cast<POBJECT_DIRECTORY_INFORMATION>(PBYTE(buf));
for(ULONG i = 0; i < idx - start; i++)
{
if(0 == wcsncmp(pdilist[i].TypeName.Buffer, L"Device", pdilist[i].TypeName.Length / sizeof(WCHAR)))
{
_tprintf(_T("%s\n"), pdilist[i].Name.Buffer);
}
}
}
if(STATUS_MORE_ENTRIES == ntStatus)
{
start = idx;
restart = FALSE;
continue;
}
if((STATUS_SUCCESS == ntStatus) || (STATUS_NO_MORE_ENTRIES == ntStatus))
{
break;
}
}
(void)NtClose_(hDeviceDir);
return 0;
}
_tprintf(_T("Failed NtOpenDirectoryObject with 0x%08X"), ntStatus);
return 1;
}
int _tmain(int /*argc*/, _TCHAR** /*argv*/)
{
HMODULE hNtDll = ::GetModuleHandle(_T("ntdll.dll"));
*(FARPROC*)&NtOpenDirectoryObject = ::GetProcAddress(hNtDll, "NtOpenDirectoryObject");
*(FARPROC*)&NtQueryDirectoryObject = ::GetProcAddress(hNtDll, "NtQueryDirectoryObject");
*(FARPROC*)&RtlInitUnicodeString_ = ::GetProcAddress(hNtDll, "RtlInitUnicodeString");
*(FARPROC*)&NtClose_ = ::GetProcAddress(hNtDll, "NtClose");
if (!NtOpenDirectoryObject || !NtQueryDirectoryObject || !RtlInitUnicodeString_ || !NtClose_)
{
_tprintf(_T("Failed to retrieve ntdll.dll function pointers\n"));
return 1;
}
return PrintDevices();
}
Some remarks: This will not delve into subdirectories, it will not list any types other than Device and it will not resolve symbolic links, if any. For any of those features, please look at the aforementioned utility's source code and adjust as needed. winternl.h should be available in any recent Windows SDK.
The functions RtlInitUnicodeString_ and NtClose_ have a trailing underscore to avoid clashes with these native API functions, which are declared in winternl.h, but use __declspec(dllimport).
Disclosure: I am the author of ntobjx.
You can use NtOpenDirectoryObject and NtQueryDirectoryObject to enumarate the objects list in a given directory.
To get the details of the object namespace, you must use the Windows NT Undocumented API. That is also used by the WinObj as it is described here that how WinOBj getting the all results..and for those who are saying that we need a driver to do this please, read these lines on given page.
"One obvious way is to use a driver – in kernel mode everything is accessible – so the client app can get the required information by communicating with its own driver. WinObj does not use a driver, however (this is one reason it’s able to execute without admin privileges, although with admin privileges it shows all objects as opposed to partial results)."
You can start with SetupDiCreateDeviceInfoList and use other related functions to enumerate all the devices. This stuff is painful to use.