How to trace event logs from provider "Microsoft-Windows-RPC" programmatically - winapi

I want to create a program that will trace event logs from the provider "Microsoft-Windows-RPC".
The program logman.exe by Microsoft is doing it like that:
logman start RPC_ONLY -p Microsoft-Windows-RPC -ets
When done, you can capture the logs like that:
tracerpt RPC_ONLY.etl -o RPC_ONLY.evtx -of EVTX
logman stop RPC_ONLY -ets
I want my program to be able to trace it like logman does but I didn't understand how.
Is there a function that I can "tell" windows that I want it to start tracing events related to Microsoft-Windows-RPC?

According to Example that Creates a Session and Enables a Manifest-based or Classic Provider, I have traced Microsoft-Windows-RPC events successfully with some changes. With log.etl, you can then Retrieve Event Data.
#include <windows.h>
#include <stdio.h>
#include <conio.h>
#include <strsafe.h>
#include <wmistr.h>
#include <evntrace.h>
#define LOGFILE_PATH L"C:\\log.etl"
#define LOGSESSION_NAME L"My Event Trace Session"
// GUID that identifies your trace session.
// Remember to create your own session GUID.
// {AE44CB98-BD11-4069-8093-770EC9258A12}
//static const GUID SessionGuid = { 0xae44cb98, 0xbd11, 0x4069, { 0x80, 0x93, 0x77, 0xe, 0xc9, 0x25, 0x8a, 0x12 } };
// GUID that identifies the provider that you want
// to enable to your session.
// {D8909C24-5BE9-4502-98CA-AB7BDC24899D}
/*
name: Microsoft-Windows-RPC
guid: 6ad52b32-d609-4be9-ae07-ce8dae937e39
*/
static const GUID ProviderGuid =
{ 0x6ad52b32, 0xd609, 0x4be9, {0xae, 0x07, 0xce, 0x8d, 0xae, 0x93, 0x7e, 0x39 } };
void wmain(void)
{
ULONG status = ERROR_SUCCESS;
TRACEHANDLE SessionHandle = 0;
EVENT_TRACE_PROPERTIES* pSessionProperties = NULL;
ULONG BufferSize = 0;
BOOL TraceOn = TRUE;
// Allocate memory for the session properties. The memory must
// be large enough to include the log file name and session name,
// which get appended to the end of the session properties structure.
BufferSize = sizeof(EVENT_TRACE_PROPERTIES) + sizeof(LOGFILE_PATH) + sizeof(LOGSESSION_NAME);
pSessionProperties = (EVENT_TRACE_PROPERTIES*)malloc(BufferSize);
if (NULL == pSessionProperties)
{
wprintf(L"Unable to allocate %d bytes for properties structure.\n", BufferSize);
goto cleanup;
}
// Set the session properties. You only append the log file name
// to the properties structure; the StartTrace function appends
// the session name for you.
ZeroMemory(pSessionProperties, BufferSize);
pSessionProperties->Wnode.BufferSize = BufferSize;
pSessionProperties->Wnode.Flags = WNODE_FLAG_TRACED_GUID;
pSessionProperties->Wnode.ClientContext = 1; //QPC clock resolution
//pSessionProperties->Wnode.Guid = SessionGuid;
pSessionProperties->Wnode.Guid = {};
pSessionProperties->LogFileMode = EVENT_TRACE_FILE_MODE_SEQUENTIAL;
pSessionProperties->MaximumFileSize = 1; // 1 MB
pSessionProperties->LoggerNameOffset = sizeof(EVENT_TRACE_PROPERTIES);
pSessionProperties->LogFileNameOffset = sizeof(EVENT_TRACE_PROPERTIES) + sizeof(LOGSESSION_NAME);
StringCbCopy((LPWSTR)((char*)pSessionProperties + pSessionProperties->LogFileNameOffset), sizeof(LOGFILE_PATH), LOGFILE_PATH);
// Create the trace session.
status = StartTrace((PTRACEHANDLE)&SessionHandle, LOGSESSION_NAME, pSessionProperties);
if (ERROR_SUCCESS != status)
{
wprintf(L"StartTrace() failed with %lu\n", status);
goto cleanup;
}
// Enable the providers that you want to log events to your session.
status = EnableTraceEx2(
SessionHandle,
(LPCGUID)&ProviderGuid,
EVENT_CONTROL_CODE_ENABLE_PROVIDER,
TRACE_LEVEL_INFORMATION,
0,
0,
0,
NULL
);
if (ERROR_SUCCESS != status)
{
wprintf(L"EnableTrace() failed with %lu\n", status);
TraceOn = FALSE;
goto cleanup;
}
wprintf(L"Run the provider application. Then hit any key to stop the session.\n");
_getch();
cleanup:
if (SessionHandle)
{
if (TraceOn)
{
status = EnableTraceEx2(
SessionHandle,
(LPCGUID)&ProviderGuid,
EVENT_CONTROL_CODE_DISABLE_PROVIDER,
TRACE_LEVEL_INFORMATION,
0,
0,
0,
NULL
);
}
status = ControlTrace(SessionHandle, LOGSESSION_NAME, pSessionProperties, EVENT_TRACE_CONTROL_STOP);
if (ERROR_SUCCESS != status)
{
wprintf(L"ControlTrace(stop) failed with %lu\n", status);
}
}
if (pSessionProperties)
{
free(pSessionProperties);
pSessionProperties = NULL;
}
}

Related

How to uniquely identify a redirected by EasyPrint printer on an RDP session in Delphi (or via Windows API)?

I like to uniquely identify a redirected by EasyPrint printer on an RDP session in Delphi. Each time a user connects to the RDP session, the name of the printer change, e.g.: "HPLJP1606 (redirected 6)". The last number (6) is always changing to ensure the printer name is unique across the server. In my program, I like to save some printer related parameters that are dependent to the printer model. I was expecting to find something like a GUID to identify the printer somewhere a bit like a MAC address. It should allow my program to ensure it's the same printer than previously selected.
Me and my colleagues looked into this solution:
How can I uniquely identify a print queue on Windows even if the queue is renamed?
This wouldn't work because the GUID is different for each session.
We also tried some system workaround to rename the printer but it's not easy to generalize.
Is there a way to identify the underlying EasyPrint printer without using the printer name in Delphi or via Windows API?
I use Delphi 10.2
Thanks in advance,
I do not use delphi but this should help you. What you need to use are the following functions from setup class.
SetupDiGetClassDevs
SetupDiEnumDeviceInfo
SetupDiGetDeviceRegistryProperty
Hardware Class IDs
Here is a crude sample Cpp code that I wrote. No matter if the printer is local/network/redirected rdp printer, the hardware Id will always be same even if the name is different.
#include <Windows.h>
#include <stdio.h>
#include <SetupAPI.h>
#pragma comment(lib, "setupapi.lib")
void PrintPrinterIds(REFGUID ClassGuid)
{
HDEVINFO hDevInfo = SetupDiGetClassDevs(&ClassGuid, NULL, NULL, DIGCF_PRESENT);
if (hDevInfo == INVALID_HANDLE_VALUE)
{
wprintf(L"Cannot get devices : %d\n", GetLastError());
return;
}
int idx = 0;
DWORD errorVal = ERROR_SUCCESS;
while (true)
{
SP_DEVINFO_DATA devInfoData = {};
WCHAR regProp[512];
devInfoData.cbSize = sizeof(devInfoData);
if (!SetupDiEnumDeviceInfo(hDevInfo, idx, &devInfoData))
{
errorVal = GetLastError();
break;
}
if (!SetupDiGetDeviceRegistryProperty(
hDevInfo,
&devInfoData,
SPDRP_FRIENDLYNAME,
NULL,
(PBYTE)regProp,
sizeof(regProp),
NULL))
{
errorVal = GetLastError();
break;
}
wprintf(L"Friendly name = %s\n", regProp);
if (!SetupDiGetDeviceRegistryProperty(
hDevInfo,
&devInfoData,
SPDRP_HARDWAREID,
NULL,
(PBYTE)regProp,
sizeof(regProp),
NULL))
{
errorVal = GetLastError();
break;
}
// hardwareId is reg_multi_sz
// Print all of the hardware ids for this device
PWCHAR pId = regProp;
do
{
wprintf(L"HardwareId = %s\n", pId);
pId += wcslen(pId) + 1;
} while (pId[0] != 0);
// Point to next device
idx++;
}
if (errorVal != ERROR_NO_MORE_ITEMS)
{
printf("Error : %d\n", errorVal);
}
SetupDiDestroyDeviceInfoList(hDevInfo);
}
int main()
{
// {4d36e979-e325-11ce-bfc1-08002be10318}
static const GUID PrinterClass =
{ 0x4d36e979, 0xe325, 0x11ce, { 0xbf, 0xc1, 0x08, 0x00, 0x2b, 0xe1, 0x03, 0x18 } };
PrintPrinterIds(PrinterClass);
// L"{1ed2bbf9-11f0-4084-b21f-ad83a8e6dcdc}"
static const GUID PrinterQueue =
{ 0x1ed2bbf9, 0x11f0, 0x4084, { 0xb2, 0x1f, 0xad, 0x83, 0xa8, 0xe6, 0xdc, 0xdc } };
PrintPrinterIds(PrinterQueue);
}

USN NFTS change notification event interrupt

I'm trying to find a way to let the system tell me whenever there's a new entry in the USN Change Journal to track modifications made to files and directories on an NTFS volume (Server 2008/2012).
This way I don't have to constantly poll the journal and can just let my thread sleep until I get notified when there's a new change-event.
However, is there even such an interrupt?
The FSCTL_QUERY_USN_JOURNAL function doesn't specifically mention interrupts (events, notifications), nor have I been able to find another way to achieve this with less intensive poll-and-compare techniques.
I'm not a hard-core programmer so there may be simpler ways to tie these functions to interrupts that I'm not aware of.
Could I perhaps find out where the USN Change Journal is stored and watch that file with another process that can generate and interrupt on change?
https://msdn.microsoft.com/en-us/library/aa365729(v=vs.85).aspx
The code posted here blocks the executing thread till the new USN record is created in the Journal. When new records arrive, the thread awakens and you can process changes and/or notify listeners via a callback that filesystem has changed (in the example it just prints message to the console). Then the thread blocks again. This example uses one thread per volume (so for each volume, separate NTFSChangesWatcher class instance needed).
It is not specified which tools or language you use, so I will write as I did it. To run this code, create a Visual Studio C++ Win32 Console Application.
Create NTFSChangesWatcher class. Paste this code in NTFSChangesWatcher.h file (replacing auto-generated one):
#pragma once
#include <windows.h>
#include <memory>
class NTFSChangesWatcher
{
public:
NTFSChangesWatcher(char drive_letter);
~NTFSChangesWatcher() = default;
// Method which runs an infinite loop and waits for new update sequence number in a journal.
// The thread is blocked till the new USN record created in the journal.
void WatchChanges();
private:
HANDLE OpenVolume(char drive_letter);
bool CreateJournal(HANDLE volume);
bool LoadJournal(HANDLE volume, USN_JOURNAL_DATA* journal_data);
bool NTFSChangesWatcher::WaitForNextUsn(PREAD_USN_JOURNAL_DATA read_journal_data) const;
std::unique_ptr<READ_USN_JOURNAL_DATA> GetWaitForNextUsnQuery(USN start_usn);
bool NTFSChangesWatcher::ReadJournalRecords(PREAD_USN_JOURNAL_DATA journal_query, LPVOID buffer,
DWORD& byte_count) const;
std::unique_ptr<READ_USN_JOURNAL_DATA> NTFSChangesWatcher::GetReadJournalQuery(USN low_usn);
char drive_letter_;
HANDLE volume_;
std::unique_ptr<USN_JOURNAL_DATA> journal_;
DWORDLONG journal_id_;
USN last_usn_;
// Flags, which indicate which types of changes you want to listen.
static const int FILE_CHANGE_BITMASK;
static const int kBufferSize;
};
and this code in NTFSChangesWatcher.cpp file:
#include "NTFSChangesWatcher.h"
#include <iostream>
using namespace std;
const int NTFSChangesWatcher::kBufferSize = 1024 * 1024 / 2;
const int NTFSChangesWatcher::FILE_CHANGE_BITMASK =
USN_REASON_RENAME_NEW_NAME | USN_REASON_SECURITY_CHANGE | USN_REASON_BASIC_INFO_CHANGE | USN_REASON_DATA_OVERWRITE |
USN_REASON_DATA_TRUNCATION | USN_REASON_DATA_EXTEND | USN_REASON_CLOSE;
NTFSChangesWatcher::NTFSChangesWatcher(char drive_letter) :
drive_letter_(drive_letter)
{
volume_ = OpenVolume(drive_letter_);
journal_ = make_unique<USN_JOURNAL_DATA>();
bool res = LoadJournal(volume_, journal_.get());
if (!res) {
cout << "Failed to load journal" << endl;
return;
}
journal_id_ = journal_->UsnJournalID;
last_usn_ = journal_->NextUsn;
}
HANDLE NTFSChangesWatcher::OpenVolume(char drive_letter) {
wchar_t pattern[10] = L"\\\\?\\a:";
pattern[4] = static_cast<wchar_t>(drive_letter);
HANDLE volume = nullptr;
volume = CreateFile(
pattern, // lpFileName
// also could be | FILE_READ_DATA | FILE_READ_ATTRIBUTES | SYNCHRONIZE
GENERIC_READ | GENERIC_WRITE | SYNCHRONIZE, // dwDesiredAccess
FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, // share mode
NULL, // default security attributes
OPEN_EXISTING, // disposition
// It is always set, no matter whether you explicitly specify it or not. This means, that access
// must be aligned with sector size so we can only read a number of bytes that is a multiple of the sector size.
FILE_FLAG_NO_BUFFERING, // file attributes
NULL // do not copy file attributes
);
if (volume == INVALID_HANDLE_VALUE) {
// An error occurred!
cout << "Failed to open volume" << endl;
return nullptr;
}
return volume;
}
bool NTFSChangesWatcher::CreateJournal(HANDLE volume) {
DWORD byte_count;
CREATE_USN_JOURNAL_DATA create_journal_data;
bool ok = DeviceIoControl(volume, // handle to volume
FSCTL_CREATE_USN_JOURNAL, // dwIoControlCode
&create_journal_data, // input buffer
sizeof(create_journal_data), // size of input buffer
NULL, // lpOutBuffer
0, // nOutBufferSize
&byte_count, // number of bytes returned
NULL) != 0; // OVERLAPPED structure
if (!ok) {
// An error occurred!
}
return ok;
}
bool NTFSChangesWatcher::LoadJournal(HANDLE volume, USN_JOURNAL_DATA* journal_data) {
DWORD byte_count;
// Try to open journal.
if (!DeviceIoControl(volume, FSCTL_QUERY_USN_JOURNAL, NULL, 0, journal_data, sizeof(*journal_data), &byte_count,
NULL)) {
// If failed (for example, in case journaling is disabled), create journal and retry.
if (CreateJournal(volume)) {
return LoadJournal(volume, journal_data);
}
return false;
}
return true;
}
void NTFSChangesWatcher::WatchChanges() {
auto u_buffer = make_unique<char[]>(kBufferSize);
auto read_journal_query = GetWaitForNextUsnQuery(last_usn_);
while (true) {
// This function does not return until new USN record created.
WaitForNextUsn(read_journal_query.get());
cout << "New entry created in the journal!" << endl;
auto journal_query = GetReadJournalQuery(read_journal_query->StartUsn);
DWORD byte_count;
if (!ReadJournalRecords(journal_query.get(), u_buffer.get(), byte_count)) {
// An error occurred.
cout << "Failed to read journal records" << endl;
}
last_usn_ = *(USN*)u_buffer.get();
read_journal_query->StartUsn = last_usn_;
// If you need here you can:
// Read and parse Journal records from the buffer.
// Notify an NTFSChangeObservers about journal changes.
}
}
bool NTFSChangesWatcher::WaitForNextUsn(PREAD_USN_JOURNAL_DATA read_journal_data) const {
DWORD bytes_read;
bool ok = true;
// This function does not return until new USN record created.
ok = DeviceIoControl(volume_, FSCTL_READ_USN_JOURNAL, read_journal_data, sizeof(*read_journal_data),
&read_journal_data->StartUsn, sizeof(read_journal_data->StartUsn), &bytes_read,
nullptr) != 0;
return ok;
}
unique_ptr<READ_USN_JOURNAL_DATA> NTFSChangesWatcher::GetWaitForNextUsnQuery(USN start_usn) {
auto query = make_unique<READ_USN_JOURNAL_DATA>();
query->StartUsn = start_usn;
query->ReasonMask = 0xFFFFFFFF; // All bits.
query->ReturnOnlyOnClose = FALSE; // All entries.
query->Timeout = 0; // No timeout.
query->BytesToWaitFor = 1; // Wait for this.
query->UsnJournalID = journal_id_; // The journal.
query->MinMajorVersion = 2;
query->MaxMajorVersion = 2;
return query;
}
bool NTFSChangesWatcher::ReadJournalRecords(PREAD_USN_JOURNAL_DATA journal_query, LPVOID buffer,
DWORD& byte_count) const {
return DeviceIoControl(volume_, FSCTL_READ_USN_JOURNAL, journal_query, sizeof(*journal_query), buffer, kBufferSize,
&byte_count, nullptr) != 0;
}
unique_ptr<READ_USN_JOURNAL_DATA> NTFSChangesWatcher::GetReadJournalQuery(USN low_usn) {
auto query = make_unique<READ_USN_JOURNAL_DATA>();
query->StartUsn = low_usn;
query->ReasonMask = 0xFFFFFFFF; // All bits.
query->ReturnOnlyOnClose = FALSE;
query->Timeout = 0; // No timeout.
query->BytesToWaitFor = 0;
query->UsnJournalID = journal_id_;
query->MinMajorVersion = 2;
query->MaxMajorVersion = 2;
return query;
}
Now you can use it (for example in the main function for testing):
#include "NTFSChangesWatcher.h"
int _tmain(int argc, _TCHAR* argv[])
{
auto watcher = new NTFSChangesWatcher('z');
watcher->WatchChanges();
return 0;
}
And console output should be like this on every change in the filesystem:
This code was slightly reworked to remove unrelated details and is a part of the Indexer++ project. So for more details, you can refer to the original code.
You can use Journal, but in this case I'd use easier method via registering a directory notification by calling the FindFirstChangeNotification or ReadDirectoryChangesW functions, see https://msdn.microsoft.com/en-us/library/aa364417.aspx
If you'd prefer to use Journal, this is - I think - the best introductory article with many examples. It is written for W2K, but those concepts are still valid: https://www.microsoft.com/msj/0999/journal/journal.aspx

select with other objects than sockets on windows

I'm facing an issue doing a select() call waiting on a socket + pipe.
I know there are already some topics on that but I have read lots of things and their opposite and I can't figure out what is the best solution for my problem.
The best for me would be to use WaitForMultipleObjects() listening on these two objects but when I try to call it only on the WSAEvent object, it fails and last error catch is code 6 (Invalid Handle).
WSAEVENT sockEvent = WSACreateEvent();
sockEvent = WSAEventSelect(fd, sockEvent, FD_WRITE);
HANDLE *pHandles = &sockEvent;
DWORD dwEvent = WaitForMultipleObjects(1, pHandles, FALSE, amqp_time_ms_until(deadline));
switch (dwEvent)
{
// ghEvents[0] was signaled
case WAIT_OBJECT_0 + 0:
// TODO: Perform tasks required by this event
return AMQP_STATUS_OK;
// ghEvents[1] was signaled
case WAIT_OBJECT_0 + 1:
// TODO: Perform tasks required by this event
return AMQP_STATUS_POLL_EXTERNAL_WAKE;
case WAIT_TIMEOUT:
return AMQP_STATUS_TIMEOUT;
// Return value is invalid.
default:
return AMQP_STATUS_SOCKET_ERROR;
}
So WaitForMultipleObjects doesn't seems to Work with WinSocks events, however I have already seen some examples on the net working with it.
And the of WSACreateEvent documentation (https://msdn.microsoft.com/en-us/library/windows/desktop/ms741561%28v=vs.85%29.aspx) says this :
Windows Sockets 2 event objects are system objects in Windows
environments. Therefore, if a Windows application wants to use an
auto-reset event rather than a manual-reset event, the application can
call the CreateEvent function directly.
This doesn't mean that WSAEvent are based on regular windows events ? If it's the case why it doesn't work with WaitForMultipleObjects ? The doc says it can handle regular events.
Thanks for helping.
This is your problem:
sockEvent = WSAEventSelect(fd, sockEvent, FD_WRITE);
You're overwriting the event handle! (As documented, the return value for WSAEventSelect is either 0 or SOCKET_ERROR. It is not a new event handle.)
Try something like
if (WSAEventSelect(fd, sockEvent, FD_WRITE) != 0) return SOCKET_ERROR;
Looking at the declaration of WSAEVENT revealed that WSAEVENT is simply an alias for HANDLE. This explains the note of the WSACreateEvent documentation you added to your post. So WSACreateEvent simply creates a manual reset event by calling CreateEvent(..., TRUE, FALSE, ...);.
Therefore an event returned by WSACreateEvent has to work along with WaitForMultipleObjects(..).
According to the code you've posted I cannot see any reason why WaitForMultipleObjects(..) should return "invalid handle" when supplied with an event returned by WSACreateEvent...
It may be though that pipes do not work with WaitForMultipleObjects(..). I remember having problems with that a long time ago but I cannot remember the details right now. But maybe it is another place to start digging...
Here is the code of my little test application which creates two threads (one event thread signalling a normal event and a simple TCP/IP server sending data). In the main loop a connection to the server is established and signalled events are processed.
#include <winsock2.h>
#include <windows.h>
#include <stdio.h>
#include <stdlib.h>
#include <conio.h>
#pragma comment(lib, "Ws2_32.lib");
#define SERVER_PORT 5000
HANDLE hSomeEvent;
HANDLE hSocketEvent;
DWORD WINAPI eventThread(LPVOID pData)
{
while (1)
{
SleepEx(2250, FALSE);
SetEvent(hSomeEvent);
}
return (0);
}
DWORD WINAPI serverThread(LPVOID pData)
{
SOCKET listener;
struct sockaddr_in sockaddr;
int size;
SOCKET client;
listener = socket(AF_INET, SOCK_STREAM, 0);
if (listener == INVALID_SOCKET)
{
printf("Could not create socket : %d" , WSAGetLastError());
}
sockaddr.sin_family = AF_INET;
sockaddr.sin_addr.s_addr = INADDR_ANY;
sockaddr.sin_port = htons(SERVER_PORT);
if (bind(listener, (struct sockaddr *)&sockaddr , sizeof(sockaddr)) == SOCKET_ERROR)
{
printf("Bind failed with error code : %d" , WSAGetLastError());
}
listen(listener, 1);
while (listener)
{
size = sizeof(struct sockaddr_in);
client = accept(listener, (struct sockaddr *)&sockaddr, &size);
printf("client connected\n");
while (client != INVALID_SOCKET)
{
SleepEx(5000, FALSE);
if (send(client, "hello\0", 6, 0) != 6)
{
closesocket(client);
shutdown(client, 2);
client = INVALID_SOCKET;
}
}
SetEvent(hSomeEvent);
}
return (0);
}
int main()
{
WSADATA wsaData;
HANDLE events[2];
DWORD result;
SOCKET s;
struct hostent *hp;
struct sockaddr_in sockaddr;
int len;
char buff[1024 * 16];
HANDLE *evtPtr;
WSAStartup(MAKEWORD(2, 2), &wsaData);
hSocketEvent = WSACreateEvent();
//hSocketEvent = CreateEvent(NULL, FALSE, FALSE, "socket_event");
hSomeEvent = CreateEvent(NULL, FALSE, FALSE, "some_event");
CreateThread(NULL, 0, eventThread, NULL, 0, &result);
CreateThread(NULL, 0, serverThread, NULL, 0, &result);
s = socket(AF_INET, SOCK_STREAM, 0);
if (s == INVALID_SOCKET)
{
printf("Could not create socket : %d" , WSAGetLastError());
}
hp = gethostbyname("127.0.0.1");
sockaddr.sin_addr.s_addr = *((unsigned long*)hp->h_addr);
sockaddr.sin_family = AF_INET;
sockaddr.sin_port = htons(SERVER_PORT);
if (connect(s, (struct sockaddr*)&sockaddr, sizeof(sockaddr)))
{
closesocket(s);
printf("Could not connect socket : %d" , WSAGetLastError());
}
WSAEventSelect(s, hSocketEvent, FD_READ);
do
{
//events[0] = hSocketEvent;
//events[1] = hSomeEvent;
//result = WaitForMultipleObjects(2, events, FALSE, 1000);
evtPtr = &hSocketEvent;
result = WaitForMultipleObjects(1, evtPtr, FALSE, 1000);
switch (result)
{
case WAIT_OBJECT_0 + 0:
printf("hSocketEvent is signalled!\n");
len = recv(s, buff, sizeof(buff), 0);
printf(" %d bytes received\n", len);
WSAResetEvent(hSocketEvent);
break;
case WAIT_OBJECT_0 + 1:
printf("hSomeEvent is signalled!\n");
break;
case WAIT_TIMEOUT:
printf("timeout\n");
break;
default:
printf("error = %d\n", GetLastError());
break;
}
}
while (1);
printf("\n\nend.");
getch();
return (0);
}
Note that if you use WSACreateEvent you have to manually reset the event after readinng the data (otherwise WaitForMultipleObjects(..) will go nuts).

Parsing events in real time ETW consumer on Windows

We are working on ETW real time consumer application by referring to https://msdn.microsoft.com/en-us/library/windows/desktop/aa364157(v=vs.85).aspx sample.
We have been successful getting callback and print "ParentGuid" of EVENT_TRACE structure within callback. However we are getting MofData pointer as always NULL and MofLength as always 0 (zero).
On the other hand if we use non real time ETW consumer method i.e. file mode; reading from .etl file we are able to get valid MofData pointer.
We are trying to consume Kernel events such as CPU usage, DISK IO details from Events in real time.
So does it mean we cannot consume Kernel events in real time? Can some one suggest why we are not getting valid pointer/MofData?
// ConsoleApplication5.cpp : Defines the entry point for the console application.
//
//Turns the DEFINE_GUID for EventTraceGuid into a const.
#define INITGUID
#include "stdafx.h"
#include <windows.h>
#include <stdio.h>
#include <evntrace.h>
#define LOGSESSION_NAME L"power"
// Used to calculate CPU usage
ULONG g_TimerResolution = 0;
void WINAPI ProcessEvent(PEVENT_TRACE pEvent);
void wmain(void)
{
ULONG status = ERROR_SUCCESS;
EVENT_TRACE_LOGFILE trace;
TRACE_LOGFILE_HEADER* pHeader = &trace.LogfileHeader;
TRACEHANDLE hTrace = 0;
HRESULT hr = S_OK;
// Identify the log file from which you want to consume events
// and the callbacks used to process the events and buffers.
ZeroMemory(&trace, sizeof(EVENT_TRACE_LOGFILE));
trace.LoggerName = (LPWSTR)LOGSESSION_NAME;
trace.CurrentTime = 0;
trace.BuffersRead = 0;
trace.BufferSize = 0;
trace.Filled = 0;
trace.EventsLost = 0;
trace.Context = NULL;
trace.ProcessTraceMode = PROCESS_TRACE_MODE_REAL_TIME | PROCESS_TRACE_MODE_EVENT_RECORD;
trace.EventCallback = (PEVENT_CALLBACK)(ProcessEvent);
trace.BufferCallback = (PEVENT_TRACE_BUFFER_CALLBACK)(ProcessBuffer);
hTrace = OpenTrace(&trace);
if ((TRACEHANDLE)INVALID_HANDLE_VALUE == hTrace)
{
wprintf(L"OpenTrace failed with %lu\n", GetLastError());
goto cleanup;
}
if (pHeader->TimerResolution > 0)
{
g_TimerResolution = pHeader->TimerResolution / 10000;
}
wprintf(L"Number of events lost: %lu\n", pHeader->EventsLost);
// Use pHeader to access all fields prior to LoggerName.
// Adjust pHeader based on the pointer size to access
// all fields after LogFileName. This is required only if
// you are consuming events on an architecture that is
// different from architecture used to write the events.
if (pHeader->PointerSize != sizeof(PVOID))
{
pHeader = (PTRACE_LOGFILE_HEADER)((PUCHAR)pHeader +
2 * (pHeader->PointerSize - sizeof(PVOID)));
}
wprintf(L"Number of buffers lost: %lu\n\n", pHeader->BuffersLost);
status = ProcessTrace(&hTrace, 1, 0, 0);
if (status != ERROR_SUCCESS && status != ERROR_CANCELLED)
{
wprintf(L"ProcessTrace failed with %lu\n", status);
goto cleanup;
}
cleanup:
if ((TRACEHANDLE)INVALID_HANDLE_VALUE != hTrace)
{
status = CloseTrace(hTrace);
}
}
VOID WINAPI ProcessEvent(PEVENT_TRACE pEvent)
{
PBYTE pEventData = NULL;
pEventData = (PBYTE)(pEvent->MofData);
printf("\n hi%d", pEventData);
printf("\n length %d", pEvent->MofLength);
}

How to get Drive Letter and Name

I want to get Drive Letter and Name.
I used "DeviceIoControl" and "IOCTL_DISK_GET_DRIVE_LAYOUT_EX" for this reason. I am using Microsoft Visual C++ ultimate Edition.
#define wszDrive L"\\\\.\\PhysicalDrive0"
BOOL GetDriveParition(LPWSTR wszPath, DRIVE_LAYOUT_INFORMATION_EX *pdg)
{
HANDLE hDevice = INVALID_HANDLE_VALUE; // handle to the drive to be examined
BOOL bResult = FALSE; // results flag
DWORD junk = 0; // discard results
hDevice = CreateFileW(wszPath, // drive to open
0, // no access to the drive
FILE_SHARE_READ | // share mode
FILE_SHARE_WRITE,
NULL, // default security attributes
OPEN_EXISTING, // disposition
0, // file attributes
NULL); // do not copy file attributes
if (hDevice == INVALID_HANDLE_VALUE) // cannot open the drive
{
return (FALSE);
}
bResult = DeviceIoControl(hDevice, // device to be queried
IOCTL_DISK_GET_DRIVE_LAYOUT_EX, // operation to perform
NULL,
0, // no input buffer
pdg,
sizeof(*pdg), // output buffer
&junk, // # bytes returned
NULL); // synchronous I/O
CloseHandle(hDevice);
return (bResult);
}
int wmain(int argc, wchar_t *argv[])
{
DRIVE_LAYOUT_INFORMATION_EX pdg; // disk drive partition structure
BOOL bResult = FALSE; // generic results flag
bResult = GetDriveParition (wszDrive, &pdg);
if (bResult)
{
wprintf(L"Drive path = %ws\n", wszDrive);
wprintf(L"Partition Style = %I64d\n", pdg.PartitionStyle);
wprintf(L"Partition Count = %ld\n", pdg.PartitionCount);
}
else
{
wprintf (L"GetDrivePartition failed. Error %ld.\n", GetLastError ());
}
getch();
}
but when I was performing I confronted to an error which was "error 122".
I think that you meant to say error code 122 rather than 22. That error is ERROR_INSUFFICIENT_BUFFER. As documented, you will need to allocate a larger buffer and try again.
The point here is that the struct is a variable sized struct. You need to allocate dynamic memory large enough to hold information for all the partitions.
Something like this should get you going in the right direction:
#include <stdio.h>
#include <stdlib.h>
#include <windows.h>
#define wszDrive L"\\\\.\\PhysicalDrive0"
BOOL GetDriveParition(LPWSTR wszPath, DRIVE_LAYOUT_INFORMATION_EX *pdg, size_t size)
{
HANDLE hDevice = INVALID_HANDLE_VALUE; // handle to the drive to be examined
BOOL bResult = FALSE; // results flag
DWORD junk = 0; // discard results
hDevice = CreateFileW(wszPath, // drive to open
0, // no access to the drive
FILE_SHARE_READ | // share mode
FILE_SHARE_WRITE,
NULL, // default security attributes
OPEN_EXISTING, // disposition
0, // file attributes
NULL); // do not copy file attributes
if (hDevice == INVALID_HANDLE_VALUE) // cannot open the drive
{
return (FALSE);
}
bResult = DeviceIoControl(hDevice, // device to be queried
IOCTL_DISK_GET_DRIVE_LAYOUT_EX, // operation to perform
NULL,
0, // no input buffer
pdg,
size, // output buffer
&junk, // # bytes returned
NULL); // synchronous I/O
CloseHandle(hDevice);
return (bResult);
}
int wmain(int argc, wchar_t *argv[])
{
DRIVE_LAYOUT_INFORMATION_EX* pdg; // disk drive partition structure
BOOL bResult = FALSE; // generic results flag
size_t size = sizeof(DRIVE_LAYOUT_INFORMATION_EX) + 10*sizeof(PARTITION_INFORMATION_EX);
pdg = (DRIVE_LAYOUT_INFORMATION_EX*) malloc(size);
bResult = GetDriveParition (wszDrive, pdg, size);
if (bResult)
{
wprintf(L"Drive path = %ws\n", wszDrive);
wprintf(L"Partition Style = %I64d\n", pdg->PartitionStyle);
wprintf(L"Partition Count = %ld\n", pdg->PartitionCount);
}
else
{
wprintf (L"GetDrivePartition failed. Error %ld.\n", GetLastError ());
}
free(pdg);
}
I've cast the return value of malloc since you state that you are using a C++ compiler.

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