Svc.cpp
The following is a complete service sample. When using this code as a template, simply add code to the sections that are prefaced by TO_DO.
When building the sample, be sure to link with Kernel32.lib and Advapi32.lib. The file Sample.h is generated when building the resource-only DLL, Sample.dll. For more information, see Sample.mc.
#include <windows.h>
#include <tchar.h>
#include <strsafe.h>
#include "sample.h"
#pragma comment(lib, "advapi32.lib")
#define SVCNAME TEXT("SvcName")
SERVICE_STATUS gSvcStatus;
SERVICE_STATUS_HANDLE gSvcStatusHandle;
HANDLE ghSvcStopEvent = NULL;
VOID SvcInstall(void);
VOID WINAPI SvcCtrlHandler( DWORD );
VOID WINAPI SvcMain( DWORD, LPTSTR * );
VOID ReportSvcStatus( DWORD, DWORD, DWORD );
VOID SvcInit( DWORD, LPTSTR * );
VOID SvcReportEvent( LPTSTR );
//
// Purpose:
// Entry point for the process
//
// Parameters:
// None
//
// Return value:
// None, defaults to 0 (zero)
//
int __cdecl _tmain(int argc, TCHAR *argv[])
{
// If command-line parameter is "install", install the service.
// Otherwise, the service is probably being started by the SCM.
if( lstrcmpi( argv[1], TEXT("install")) == 0 )
{
SvcInstall();
return 0;
}
// TO_DO: Add any additional services for the process to this table.
SERVICE_TABLE_ENTRY DispatchTable[] =
{
{ SVCNAME, (LPSERVICE_MAIN_FUNCTION) SvcMain },
{ NULL, NULL }
};
// This call returns when the service has stopped.
// The process should simply terminate when the call returns.
if (!StartServiceCtrlDispatcher( DispatchTable ))
{
SvcReportEvent(TEXT("StartServiceCtrlDispatcher"));
}
}
//
// Purpose:
// Installs a service in the SCM database
//
// Parameters:
// None
//
// Return value:
// None
//
VOID SvcInstall()
{
SC_HANDLE schSCManager;
SC_HANDLE schService;
TCHAR szUnquotedPath[MAX_PATH];
if( !GetModuleFileName( NULL, szUnquotedPath, MAX_PATH ) )
{
printf("Cannot install service (%d)\n", GetLastError());
return;
}
// In case the path contains a space, it must be quoted so that
// it is correctly interpreted. For example,
// "d:\my share\myservice.exe" should be specified as
// ""d:\my share\myservice.exe"".
TCHAR szPath[MAX_PATH];
StringCbPrintf(szPath, MAX_PATH, TEXT("\"%s\""), szUnquotedPath);
// 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;
}
// Create the service
schService = CreateService(
schSCManager, // SCM database
SVCNAME, // name of service
SVCNAME, // service name to display
SERVICE_ALL_ACCESS, // desired access
SERVICE_WIN32_OWN_PROCESS, // service type
SERVICE_DEMAND_START, // start type
SERVICE_ERROR_NORMAL, // error control type
szPath, // path to service's binary
NULL, // no load ordering group
NULL, // no tag identifier
NULL, // no dependencies
NULL, // LocalSystem account
NULL); // no password
if (schService == NULL)
{
printf("CreateService failed (%d)\n", GetLastError());
CloseServiceHandle(schSCManager);
return;
}
else printf("Service installed successfully\n");
CloseServiceHandle(schService);
CloseServiceHandle(schSCManager);
}
//
// Purpose:
// Entry point for the service
//
// Parameters:
// dwArgc - Number of arguments in the lpszArgv array
// lpszArgv - Array of strings. The first string is the name of
// the service and subsequent strings are passed by the process
// that called the StartService function to start the service.
//
// Return value:
// None.
//
VOID WINAPI SvcMain( DWORD dwArgc, LPTSTR *lpszArgv )
{
// Register the handler function for the service
gSvcStatusHandle = RegisterServiceCtrlHandler(
SVCNAME,
SvcCtrlHandler);
if( !gSvcStatusHandle )
{
SvcReportEvent(TEXT("RegisterServiceCtrlHandler"));
return;
}
// These SERVICE_STATUS members remain as set here
gSvcStatus.dwServiceType = SERVICE_WIN32_OWN_PROCESS;
gSvcStatus.dwServiceSpecificExitCode = 0;
// Report initial status to the SCM
ReportSvcStatus( SERVICE_START_PENDING, NO_ERROR, 3000 );
// Perform service-specific initialization and work.
SvcInit( dwArgc, lpszArgv );
}
//
// Purpose:
// The service code
//
// Parameters:
// dwArgc - Number of arguments in the lpszArgv array
// lpszArgv - Array of strings. The first string is the name of
// the service and subsequent strings are passed by the process
// that called the StartService function to start the service.
//
// Return value:
// None
//
VOID SvcInit( DWORD dwArgc, LPTSTR *lpszArgv)
{
// TO_DO: Declare and set any required variables.
// Be sure to periodically call ReportSvcStatus() with
// SERVICE_START_PENDING. If initialization fails, call
// ReportSvcStatus with SERVICE_STOPPED.
// Create an event. The control handler function, SvcCtrlHandler,
// signals this event when it receives the stop control code.
ghSvcStopEvent = CreateEvent(
NULL, // default security attributes
TRUE, // manual reset event
FALSE, // not signaled
NULL); // no name
if ( ghSvcStopEvent == NULL)
{
ReportSvcStatus( SERVICE_STOPPED, GetLastError(), 0 );
return;
}
// Report running status when initialization is complete.
ReportSvcStatus( SERVICE_RUNNING, NO_ERROR, 0 );
// TO_DO: Perform work until service stops.
while(1)
{
// Check whether to stop the service.
WaitForSingleObject(ghSvcStopEvent, INFINITE);
ReportSvcStatus( SERVICE_STOPPED, NO_ERROR, 0 );
return;
}
}
//
// Purpose:
// Sets the current service status and reports it to the SCM.
//
// Parameters:
// dwCurrentState - The current state (see SERVICE_STATUS)
// dwWin32ExitCode - The system error code
// dwWaitHint - Estimated time for pending operation,
// in milliseconds
//
// Return value:
// None
//
VOID ReportSvcStatus( DWORD dwCurrentState,
DWORD dwWin32ExitCode,
DWORD dwWaitHint)
{
static DWORD dwCheckPoint = 1;
// Fill in the SERVICE_STATUS structure.
gSvcStatus.dwCurrentState = dwCurrentState;
gSvcStatus.dwWin32ExitCode = dwWin32ExitCode;
gSvcStatus.dwWaitHint = dwWaitHint;
if (dwCurrentState == SERVICE_START_PENDING)
gSvcStatus.dwControlsAccepted = 0;
else gSvcStatus.dwControlsAccepted = SERVICE_ACCEPT_STOP;
if ( (dwCurrentState == SERVICE_RUNNING) ||
(dwCurrentState == SERVICE_STOPPED) )
gSvcStatus.dwCheckPoint = 0;
else gSvcStatus.dwCheckPoint = dwCheckPoint++;
// Report the status of the service to the SCM.
SetServiceStatus( gSvcStatusHandle, &gSvcStatus );
}
//
// Purpose:
// Called by SCM whenever a control code is sent to the service
// using the ControlService function.
//
// Parameters:
// dwCtrl - control code
//
// Return value:
// None
//
VOID WINAPI SvcCtrlHandler( DWORD dwCtrl )
{
// Handle the requested control code.
switch(dwCtrl)
{
case SERVICE_CONTROL_STOP:
ReportSvcStatus(SERVICE_STOP_PENDING, NO_ERROR, 0);
// Signal the service to stop.
SetEvent(ghSvcStopEvent);
ReportSvcStatus(gSvcStatus.dwCurrentState, NO_ERROR, 0);
return;
case SERVICE_CONTROL_INTERROGATE:
break;
default:
break;
}
}
//
// Purpose:
// Logs messages to the event log
//
// Parameters:
// szFunction - name of function that failed
//
// Return value:
// None
//
// Remarks:
// The service must have an entry in the Application event log.
//
VOID SvcReportEvent(LPTSTR szFunction)
{
HANDLE hEventSource;
LPCTSTR lpszStrings[2];
TCHAR Buffer[80];
hEventSource = RegisterEventSource(NULL, SVCNAME);
if( NULL != hEventSource )
{
StringCchPrintf(Buffer, 80, TEXT("%s failed with %d"), szFunction, GetLastError());
lpszStrings[0] = SVCNAME;
lpszStrings[1] = Buffer;
ReportEvent(hEventSource, // event log handle
EVENTLOG_ERROR_TYPE, // event type
0, // event category
SVC_ERROR, // event identifier
NULL, // no security identifier
2, // size of lpszStrings array
0, // no binary data
lpszStrings, // array of strings
NULL); // no binary data
DeregisterEventSource(hEventSource);
}
}
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