SERVICE.C

// THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF 
// ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO
// THE IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A
// PARTICULAR PURPOSE.
//
// Copyright 1993 - 1998 Microsoft Corporation. All Rights Reserved.
//
// MODULE: service.c
//
// PURPOSE: Implements functions required by all services
// windows.
//
// FUNCTIONS:
// main(int argc, char **argv);
// service_ctrl(DWORD dwCtrlCode);
// service_main(DWORD dwArgc, LPTSTR *lpszArgv);
// CmdInstallService();
// CmdRemoveService();
// CmdDebugService(int argc, char **argv);
// ControlHandler ( DWORD dwCtrlType );
// GetLastErrorText( LPTSTR lpszBuf, DWORD dwSize );
//
// COMMENTS:
//
// AUTHOR: Craig Link - Microsoft Developer Support
//


#include <windows.h>
#include <stdio.h>
#include <stdlib.h>
#include <process.h>
#include <tchar.h>

#include "service.h"



// internal variables
SERVICE_STATUS ssStatus; // current status of the service
SERVICE_STATUS_HANDLE sshStatusHandle;
DWORD dwErr = 0;
BOOL bDebug = FALSE;
TCHAR szErr[256];

// internal function prototypes
VOID WINAPI service_ctrl(DWORD dwCtrlCode);
VOID WINAPI service_main(DWORD dwArgc, LPTSTR *lpszArgv);
VOID CmdInstallService();
VOID CmdRemoveService();
VOID CmdDebugService(int argc, char **argv);
BOOL WINAPI ControlHandler ( DWORD dwCtrlType );
LPTSTR GetLastErrorText( LPTSTR lpszBuf, DWORD dwSize );

//
// FUNCTION: main
//
// PURPOSE: entrypoint for service
//
// PARAMETERS:
// argc - number of command line arguments
// argv - array of command line arguments
//
// RETURN VALUE:
// none
//
// COMMENTS:
// main() either performs the command line task, or
// call StartServiceCtrlDispatcher to register the
// main service thread. When the this call returns,
// the service has stopped, so exit.
//
void main(int argc, char **argv)
{
SERVICE_TABLE_ENTRY dispatchTable[] =
{
{ TEXT(SZSERVICENAME), (LPSERVICE_MAIN_FUNCTION)service_main },
{ NULL, NULL }
};

if ( (argc > 1) &&
((*argv[1] == '-') || (*argv[1] == '/')) )
{
if ( _stricmp( "install", argv[1]+1 ) == 0 )
{
CmdInstallService();
}
else if ( _stricmp( "remove", argv[1]+1 ) == 0 )
{
CmdRemoveService();
}
else if ( _stricmp( "debug", argv[1]+1 ) == 0 )
{
bDebug = TRUE;
CmdDebugService(argc, argv);
}
else
{
goto dispatch;
}
exit(0);
}

// if it doesn't match any of the above parameters
// the service control manager may be starting the service
// so we must call StartServiceCtrlDispatcher
dispatch:
// this is just to be friendly
printf( "%s -install to install the service\n", SZAPPNAME );
printf( "%s -remove to remove the service\n", SZAPPNAME );
printf( "%s -debug <params> to run as a console app for debugging\n", SZAPPNAME );
printf( "\nStartServiceCtrlDispatcher being called.\n" );
printf( "This may take several seconds. Please wait.\n" );

if (!StartServiceCtrlDispatcher(dispatchTable))
AddToMessageLog(TEXT("StartServiceCtrlDispatcher failed."));
}



//
// FUNCTION: service_main
//
// PURPOSE: To perform actual initialization of the service
//
// PARAMETERS:
// dwArgc - number of command line arguments
// lpszArgv - array of command line arguments
//
// RETURN VALUE:
// none
//
// COMMENTS:
// This routine performs the service initialization and then calls
// the user defined ServiceStart() routine to perform majority
// of the work.
//
void WINAPI service_main(DWORD dwArgc, LPTSTR *lpszArgv)
{

// register our service control handler:
//
sshStatusHandle = RegisterServiceCtrlHandler( TEXT(SZSERVICENAME), service_ctrl);

if (!sshStatusHandle)
goto cleanup;

// SERVICE_STATUS members that don't change in example
//
ssStatus.dwServiceType = SERVICE_WIN32_OWN_PROCESS;
ssStatus.dwServiceSpecificExitCode = 0;


// report the status to the service control manager.
//
if (!ReportStatusToSCMgr(
SERVICE_START_PENDING, // service state
NO_ERROR, // exit code
3000)) // wait hint
goto cleanup;


ServiceStart( dwArgc, lpszArgv );

cleanup:

// try to report the stopped status to the service control manager.
//
if (sshStatusHandle)
(VOID)ReportStatusToSCMgr(
SERVICE_STOPPED,
dwErr,
0);

return;
}



//
// FUNCTION: service_ctrl
//
// PURPOSE: This function is called by the SCM whenever
// ControlService() is called on this service.
//
// PARAMETERS:
// dwCtrlCode - type of control requested
//
// RETURN VALUE:
// none
//
// COMMENTS:
//
VOID WINAPI service_ctrl(DWORD dwCtrlCode)
{
// Handle the requested control code.
//
switch(dwCtrlCode)
{
// Stop the service.
//
case SERVICE_CONTROL_STOP:
ReportStatusToSCMgr(SERVICE_STOP_PENDING, NO_ERROR, 0);
ServiceStop();
return;

// Update the service status.
//
case SERVICE_CONTROL_INTERROGATE:
break;

// invalid control code
//
default:
break;

}

ReportStatusToSCMgr(ssStatus.dwCurrentState, NO_ERROR, 0);

}



//
// FUNCTION: ReportStatusToSCMgr()
//
// PURPOSE: Sets the current status of the service and
// reports it to the Service Control Manager
//
// PARAMETERS:
// dwCurrentState - the state of the service
// dwWin32ExitCode - error code to report
// dwWaitHint - worst case estimate to next checkpoint
//
// RETURN VALUE:
// TRUE - success
// FALSE - failure
//
// COMMENTS:
//
BOOL ReportStatusToSCMgr(DWORD dwCurrentState,
DWORD dwWin32ExitCode,
DWORD dwWaitHint)
{
static DWORD dwCheckPoint = 1;
BOOL fResult = TRUE;


if ( !bDebug ) // when debugging we don't report to the SCM
{
if (dwCurrentState == SERVICE_START_PENDING)
ssStatus.dwControlsAccepted = 0;
else
ssStatus.dwControlsAccepted = SERVICE_ACCEPT_STOP;

ssStatus.dwCurrentState = dwCurrentState;
ssStatus.dwWin32ExitCode = dwWin32ExitCode;
ssStatus.dwWaitHint = dwWaitHint;

if ( ( dwCurrentState == SERVICE_RUNNING ) ||
( dwCurrentState == SERVICE_STOPPED ) )
ssStatus.dwCheckPoint = 0;
else
ssStatus.dwCheckPoint = dwCheckPoint++;


// Report the status of the service to the service control manager.
//
if (!(fResult = SetServiceStatus( sshStatusHandle, &ssStatus))) {
AddToMessageLog(TEXT("SetServiceStatus"));
}
}
return fResult;
}



//
// FUNCTION: AddToMessageLog(LPTSTR lpszMsg)
//
// PURPOSE: Allows any thread to log an error message
//
// PARAMETERS:
// lpszMsg - text for message
//
// RETURN VALUE:
// none
//
// COMMENTS:
//
VOID AddToMessageLog(LPTSTR lpszMsg)
{
TCHAR szMsg[256];
HANDLE hEventSource;
LPTSTR lpszStrings[2];


if ( !bDebug )
{
dwErr = GetLastError();

// Use event logging to log the error.
//
hEventSource = RegisterEventSource(NULL, TEXT(SZSERVICENAME));

_stprintf(szMsg, TEXT("%s error: %d"), TEXT(SZSERVICENAME), dwErr);
lpszStrings[0] = szMsg;
lpszStrings[1] = lpszMsg;

if (hEventSource != NULL) {
ReportEvent(hEventSource, // handle of event source
EVENTLOG_ERROR_TYPE, // event type
0, // event category
0, // event ID
NULL, // current user's SID
2, // strings in lpszStrings
0, // no bytes of raw data
lpszStrings, // array of error strings
NULL); // no raw data

(VOID) DeregisterEventSource(hEventSource);
}
}
}




///////////////////////////////////////////////////////////////////
//
// The following code handles service installation and removal
//


//
// FUNCTION: CmdInstallService()
//
// PURPOSE: Installs the service
//
// PARAMETERS:
// none
//
// RETURN VALUE:
// none
//
// COMMENTS:
//
void CmdInstallService()
{
SC_HANDLE schService;
SC_HANDLE schSCManager;

TCHAR szPath[512];

if ( GetModuleFileName( NULL, szPath, 512 ) == 0 )
{
_tprintf(TEXT("Unable to install %s - %s\n"), TEXT(SZSERVICEDISPLAYNAME), GetLastErrorText(szErr, 256));
return;
}

schSCManager = OpenSCManager(
NULL, // machine (NULL == local)
NULL, // database (NULL == default)
SC_MANAGER_ALL_ACCESS // access required
);
if ( schSCManager )
{
schService = CreateService(
schSCManager, // SCManager database
TEXT(SZSERVICENAME), // name of service
TEXT(SZSERVICEDISPLAYNAME), // 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, // service's binary
NULL, // no load ordering group
NULL, // no tag identifier
TEXT(SZDEPENDENCIES), // dependencies
NULL, // LocalSystem account
NULL); // no password

if ( schService )
{
_tprintf(TEXT("%s installed.\n"), TEXT(SZSERVICEDISPLAYNAME) );
CloseServiceHandle(schService);
}
else
{
_tprintf(TEXT("CreateService failed - %s\n"), GetLastErrorText(szErr, 256));
}

CloseServiceHandle(schSCManager);
}
else
_tprintf(TEXT("OpenSCManager failed - %s\n"), GetLastErrorText(szErr,256));
}



//
// FUNCTION: CmdRemoveService()
//
// PURPOSE: Stops and removes the service
//
// PARAMETERS:
// none
//
// RETURN VALUE:
// none
//
// COMMENTS:
//
void CmdRemoveService()
{
SC_HANDLE schService;
SC_HANDLE schSCManager;

schSCManager = OpenSCManager(
NULL, // machine (NULL == local)
NULL, // database (NULL == default)
SC_MANAGER_ALL_ACCESS // access required
);
if ( schSCManager )
{
schService = OpenService(schSCManager, TEXT(SZSERVICENAME), SERVICE_ALL_ACCESS);

if (schService)
{
// try to stop the service
if ( ControlService( schService, SERVICE_CONTROL_STOP, &ssStatus ) )
{
_tprintf(TEXT("Stopping %s."), TEXT(SZSERVICEDISPLAYNAME));
Sleep( 1000 );

while( QueryServiceStatus( schService, &ssStatus ) )
{
if ( ssStatus.dwCurrentState == SERVICE_STOP_PENDING )
{
_tprintf(TEXT("."));
Sleep( 1000 );
}
else
break;
}

if ( ssStatus.dwCurrentState == SERVICE_STOPPED )
_tprintf(TEXT("\n%s stopped.\n"), TEXT(SZSERVICEDISPLAYNAME) );
else
_tprintf(TEXT("\n%s failed to stop.\n"), TEXT(SZSERVICEDISPLAYNAME) );

}

// now remove the service
if( DeleteService(schService) )
_tprintf(TEXT("%s removed.\n"), TEXT(SZSERVICEDISPLAYNAME) );
else
_tprintf(TEXT("DeleteService failed - %s\n"), GetLastErrorText(szErr,256));


CloseServiceHandle(schService);
}
else
_tprintf(TEXT("OpenService failed - %s\n"), GetLastErrorText(szErr,256));

CloseServiceHandle(schSCManager);
}
else
_tprintf(TEXT("OpenSCManager failed - %s\n"), GetLastErrorText(szErr,256));
}




///////////////////////////////////////////////////////////////////
//
// The following code is for running the service as a console app
//


//
// FUNCTION: CmdDebugService(int argc, char ** argv)
//
// PURPOSE: Runs the service as a console application
//
// PARAMETERS:
// argc - number of command line arguments
// argv - array of command line arguments
//
// RETURN VALUE:
// none
//
// COMMENTS:
//
void CmdDebugService(int argc, char ** argv)
{
DWORD dwArgc;
LPTSTR *lpszArgv;

#ifdef UNICODE
lpszArgv = CommandLineToArgvW(GetCommandLineW(), &(dwArgc) );
#else
dwArgc = (DWORD) argc;
lpszArgv = argv;
#endif

_tprintf(TEXT("Debugging %s.\n"), TEXT(SZSERVICEDISPLAYNAME));

SetConsoleCtrlHandler( ControlHandler, TRUE );

ServiceStart( dwArgc, lpszArgv );
}


//
// FUNCTION: ControlHandler ( DWORD dwCtrlType )
//
// PURPOSE: Handled console control events
//
// PARAMETERS:
// dwCtrlType - type of control event
//
// RETURN VALUE:
// True - handled
// False - unhandled
//
// COMMENTS:
//
BOOL WINAPI ControlHandler ( DWORD dwCtrlType )
{
switch( dwCtrlType )
{
case CTRL_BREAK_EVENT: // use Ctrl+C or Ctrl+Break to simulate
case CTRL_C_EVENT: // SERVICE_CONTROL_STOP in debug mode
_tprintf(TEXT("Stopping %s.\n"), TEXT(SZSERVICEDISPLAYNAME));
ServiceStop();
return TRUE;
break;

}
return FALSE;
}

//
// FUNCTION: GetLastErrorText
//
// PURPOSE: copies error message text to string
//
// PARAMETERS:
// lpszBuf - destination buffer
// dwSize - size of buffer
//
// RETURN VALUE:
// destination buffer
//
// COMMENTS:
//
LPTSTR GetLastErrorText( LPTSTR lpszBuf, DWORD dwSize )
{
DWORD dwRet;
LPTSTR lpszTemp = NULL;

dwRet = FormatMessage( FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM |FORMAT_MESSAGE_ARGUMENT_ARRAY,
NULL,
GetLastError(),
LANG_NEUTRAL,
(LPTSTR)&lpszTemp,
0,
NULL );

// supplied buffer is not long enough
if ( !dwRet || ( (long)dwSize < (long)dwRet+14 ) )
lpszBuf[0] = TEXT('\0');
else
{
lpszTemp[lstrlen(lpszTemp)-2] = TEXT('\0'); //remove cr and newline character
_stprintf( lpszBuf, TEXT("%s (0x%x)"), lpszTemp, GetLastError() );
}

if ( lpszTemp )
LocalFree((HLOCAL) lpszTemp );

return lpszBuf;
}