获取可执行文件的服务路径

Question

考虑下图。

我已经编写了以下代码，这些代码应该获取服务的 可执行文件 的路径，如图中突出显示。基本上我在下面给出的代码片段将写入另一个 cpp 文件，该文件将生成 lpa.exe 并且应该运行作为服务。我尝试了 GetModuleFileName，如果可执行文件 (lpa.exe) 通常是运行（不是作为服务），该函数会找到正确的路径。但是一旦它运行作为服务，它就不会给出正确的路径并指向 system32/...。为了解决这个问题，我相信下面的代码片段可能是解决方案：

#include <Windows.h>
#include <iostream>

int main()
{
    SC_HANDLE sHandle;
    LPQUERY_SERVICE_CONFIG lpServiceConfig = NULL;
    DWORD cbBufSize = 100;
    LPDWORD bytesNeeded = NULL;
    sHandle = OpenSCManager(NULL,NULL,SC_MANAGER_ALL_ACCESS);
    sHandle = OpenService(sHandle, "LogPointAgent",SERVICE_ALL_ACCESS);
    QueryServiceConfig(sHandle,lpServiceConfig,cbBufSize,bytesNeeded);
    std::cout << lpServiceConfig->lpBinaryPathName << std::endl;
}

代码编译但我得到异常 LearningCpp.exe 中 0x00ad1103 处未处理的异常：0xC0000005：访问冲突读取位置 0x0000000c。 这意味着我遇到与指针相关的问题.我上面给出的代码有什么问题？

Answer 1

如果您使用第三个参数指定大小，

QueryServiceConfig 需要一个指向已分配内存的指针作为第二个参数。您指定了大小，但指针为 NULL，导致崩溃。

lpServiceConfig [out, optional]

A pointer to a buffer that receives the service configuration information. The format of the data is a QUERY_SERVICE_CONFIG structure.

The maximum size of this array is 8K bytes. To determine the required size, specify NULL for this parameter and 0 for the cbBufSize parameter. The function will fail and GetLastError will return ERROR_INSUFFICIENT_BUFFER. The pcbBytesNeeded parameter will receive the required size.*

您必须为 lpServiceConfig 参数分配内存。

这里有一个官方例子：

Querying a Service's Configuration

//
// Purpose: 
//   Retrieves and displays the current service configuration.
//
// Parameters:
//   None
// 
// Return value:
//   None
//
VOID __stdcall DoQuerySvc()
{
    SC_HANDLE schSCManager;
    SC_HANDLE schService;
    LPQUERY_SERVICE_CONFIG lpsc; 
    LPSERVICE_DESCRIPTION lpsd;
    DWORD dwBytesNeeded, cbBufSize, dwError; 

    // Get a handle to the SCM database. 

    schSCManager = OpenSCManager( 
        NULL,                    // local computer
        NULL,                    // ServicesActive database 
        SC_MANAGER_ALL_ACCESS);  // full access rights 

    if (NULL == schSCManager) 
    {
        printf("OpenSCManager failed (%d)\n", GetLastError());
        return;
    }

    // Get a handle to the service.

    schService = OpenService( 
        schSCManager,          // SCM database 
        szSvcName,             // name of service 
        SERVICE_QUERY_CONFIG); // need query config access 

    if (schService == NULL)
    { 
        printf("OpenService failed (%d)\n", GetLastError()); 
        CloseServiceHandle(schSCManager);
        return;
    }

    // Get the configuration information.

    if( !QueryServiceConfig( 
        schService, 
        NULL, 
        0, 
        &dwBytesNeeded))
    {
        dwError = GetLastError();
        if( ERROR_INSUFFICIENT_BUFFER == dwError )
        {
            cbBufSize = dwBytesNeeded;
            lpsc = (LPQUERY_SERVICE_CONFIG) LocalAlloc(LMEM_FIXED, cbBufSize);
        }
        else
        {
            printf("QueryServiceConfig failed (%d)", dwError);
            goto cleanup; 
        }
    }

    if( !QueryServiceConfig( 
        schService, 
        lpsc, 
        cbBufSize, 
        &dwBytesNeeded) ) 
    {
        printf("QueryServiceConfig failed (%d)", GetLastError());
        goto cleanup;
    }

    if( !QueryServiceConfig2( 
        schService, 
        SERVICE_CONFIG_DESCRIPTION,
        NULL, 
        0, 
        &dwBytesNeeded))
    {
        dwError = GetLastError();
        if( ERROR_INSUFFICIENT_BUFFER == dwError )
        {
            cbBufSize = dwBytesNeeded;
            lpsd = (LPSERVICE_DESCRIPTION) LocalAlloc(LMEM_FIXED, cbBufSize);
        }
        else
        {
            printf("QueryServiceConfig2 failed (%d)", dwError);
            goto cleanup; 
        }
    }

    if (! QueryServiceConfig2( 
        schService, 
        SERVICE_CONFIG_DESCRIPTION,
        (LPBYTE) lpsd, 
        cbBufSize, 
        &dwBytesNeeded) ) 
    {
        printf("QueryServiceConfig2 failed (%d)", GetLastError());
        goto cleanup;
    }

    // Print the configuration information.

    _tprintf(TEXT("%s configuration: \n"), szSvcName);
    _tprintf(TEXT("  Type: 0x%x\n"), lpsc->dwServiceType);
    _tprintf(TEXT("  Start Type: 0x%x\n"), lpsc->dwStartType);
    _tprintf(TEXT("  Error Control: 0x%x\n"), lpsc->dwErrorControl);
    _tprintf(TEXT("  Binary path: %s\n"), lpsc->lpBinaryPathName);
    _tprintf(TEXT("  Account: %s\n"), lpsc->lpServiceStartName);

    if (lpsd->lpDescription != NULL && lstrcmp(lpsd->lpDescription, TEXT("")) != 0)
        _tprintf(TEXT("  Description: %s\n"), lpsd->lpDescription);
    if (lpsc->lpLoadOrderGroup != NULL && lstrcmp(lpsc->lpLoadOrderGroup, TEXT("")) != 0)
        _tprintf(TEXT("  Load order group: %s\n"), lpsc->lpLoadOrderGroup);
    if (lpsc->dwTagId != 0)
        _tprintf(TEXT("  Tag ID: %d\n"), lpsc->dwTagId);
    if (lpsc->lpDependencies != NULL && lstrcmp(lpsc->lpDependencies, TEXT("")) != 0)
        _tprintf(TEXT("  Dependencies: %s\n"), lpsc->lpDependencies);

    LocalFree(lpsc); 
    LocalFree(lpsd);

cleanup:
    CloseServiceHandle(schService); 
    CloseServiceHandle(schSCManager);
}

获取可执行文件的服务路径

Getting Service Path to Executable

c++

winapi