Windows Services Programming 22
Adding New Project for Windows Service Control Application
Next, add another new project in the same solution. This project will create Win32 application which can be used to control Windows services. Create a new empty Win32 console application project.
Then, add the source file and give it a suitable name.
Next, add the following source code.
// link with Kernel32.lib and Advapi32.lib.
#include <windows.h>
#include <strsafe.h>
#include <aclapi.h>
#include <stdio.h>
//#pragma comment(lib, advapi32.lib)
WCHAR szCommand[10];
WCHAR szSvcName[80];
SC_HANDLE schSCManager;
SC_HANDLE schService;
VOID __stdcall DisplayUsage(void);
VOID __stdcall DoStartSvc(void);
VOID __stdcall DoUpdateSvcDacl(void);
VOID __stdcall DoStopSvc(void);
BOOL __stdcall StopDependentServices(void);
// Purpose: Entry point function. Executes specified command from user.
// Parameters: Command-line syntax is: svccontrol [command] [service_name]
// Return value: None
void wmain(int argc, WCHAR *argv[])
{
wprintf(L\n);
if( argc != 3 )
{
wprintf(LERROR: Incorrect number of arguments\n\n);
DisplayUsage();
return;
}
StringCchCopy(szCommand, 10, argv[1]);
StringCchCopy(szSvcName, 80, argv[2]);
if (lstrcmpi( szCommand, Lstart) == 0 )
DoStartSvc();
else if (lstrcmpi( szCommand, Ldacl) == 0 )
DoUpdateSvcDacl();
else if (lstrcmpi( szCommand, Lstop) == 0 )
DoStopSvc();
else
{
wprintf(LUnknown command (%s)\n\n, szCommand);
DisplayUsage();
}
}
VOID __stdcall DisplayUsage()
{
wprintf(LDescription:);
wprintf(L\tCommand-line tool that controls a service.\n\n);
wprintf(LUsage:);
wprintf(L\tsvccontrol [command] [service_name]\n\n);
wprintf(L\t[command]\n);
wprintf(L\t start\n);
wprintf(L\t dacl\n);
wprintf(L\t stop\n);
}
// Purpose: Starts the service if possible.
// Parameters: None
// Return value: None
VOID __stdcall DoStartSvc()
{
SERVICE_STATUS_PROCESS ssStatus;
DWORD dwOldCheckPoint;
DWORD dwStartTickCount;
DWORD dwWaitTime;
DWORD dwBytesNeeded;
// 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)
{
wprintf(LOpenSCManager() failed, error %d\n, GetLastError());
return;
}
// Get a handle to the service
schService = OpenService(
schSCManager, // SCM database
szSvcName, // name of service
SERVICE_ALL_ACCESS); // full access
if (schService == NULL)
{
wprintf(LOpenService() failed, error %d\n, GetLastError());
CloseServiceHandle(schSCManager);
return;
}
// Check the status in case the service is not stopped.
if (!QueryServiceStatusEx(
schService, // handle to service
SC_STATUS_PROCESS_INFO, // information level
(LPBYTE) &ssStatus, // address of structure
sizeof(SERVICE_STATUS_PROCESS), // size of structure
&dwBytesNeeded ) ) // size needed if buffer is too small
{
wprintf(LQueryServiceStatusEx() failed, error %d\n, GetLastError());
CloseServiceHandle(schService);
CloseServiceHandle(schSCManager);
return;
}
// Check if the service is already running. It would be possible
// to stop the service here, but for simplicity this example just returns.
if(ssStatus.dwCurrentState != SERVICE_STOPPED && ssStatus.dwCurrentState != SERVICE_STOP_PENDING)
{
wprintf(LCannot start the %s service because it is already running\n, szSvcName);
CloseServiceHandle(schService);
CloseServiceHandle(schSCManager);
return;
}
// Save the tick count and initial checkpoint
dwStartTickCount = GetTickCount();
dwOldCheckPoint = ssStatus.dwCheckPoint;
// Wait for the service to stop before attempting to start it
while (ssStatus.dwCurrentState == SERVICE_STOP_PENDING)
{
// Do not wait longer than the wait hint. A good interval is
// one-tenth of the wait hint but not less than 1 second
// and not more than 10 seconds
dwWaitTime = ssStatus.dwWaitHint / 10;
if( dwWaitTime < 1000 )
dwWaitTime = 1000;
else if ( dwWaitTime > 10000 )
dwWaitTime = 10000;
Sleep( dwWaitTime );
// Check the status until the service is no longer stop pending
if (!QueryServiceStatusEx(
schService, // handle to service
SC_STATUS_PROCESS_INFO, // information level
(LPBYTE) &ssStatus, // address of structure
sizeof(SERVICE_STATUS_PROCESS), // size of structure
&dwBytesNeeded ) ) // size needed if buffer is too small
{
wprintf(LQueryServiceStatusEx failed (%d)\n, GetLastError());
CloseServiceHandle(schService);
CloseServiceHandle(schSCManager);
return;
}
if ( ssStatus.dwCheckPoint > dwOldCheckPoint )
{
// Continue to wait and check
dwStartTickCount = GetTickCount();
dwOldCheckPoint = ssStatus.dwCheckPoint;
}
else
{
if(GetTickCount()-dwStartTickCount > ssStatus.dwWaitHint)
{
wprintf(LTimeout waiting for %s service to stop\n, szSvcName);
CloseServiceHandle(schService);
CloseServiceHandle(schSCManager);
return;
}
}
}
// Attempt to start the service.
if (!StartService(
schService, // handle to service
0, // number of arguments
NULL) ) // no arguments
{
wprintf(LStartService() failed, error %d\n, GetLastError());
CloseServiceHandle(schService);
CloseServiceHandle(schSCManager);
return;
}
else
wprintf(LService %s start pending...\n, szSvcName);
// Check the status until the service is no longer start pending.
if (!QueryServiceStatusEx(
schService, // handle to service
SC_STATUS_PROCESS_INFO, // info level
(LPBYTE) &ssStatus, // address of structure
sizeof(SERVICE_STATUS_PROCESS), // size of structure
&dwBytesNeeded ) ) // if buffer too small
{
wprintf(LQueryServiceStatusEx failed, error %d\n, GetLastError());
CloseServiceHandle(schService);
CloseServiceHandle(schSCManager);
return;
}
// Save the tick count and initial checkpoint
dwStartTickCount = GetTickCount();
dwOldCheckPoint = ssStatus.dwCheckPoint;
while (ssStatus.dwCurrentState == SERVICE_START_PENDING)
{
// Do not wait longer than the wait hint. A good interval is
// one-tenth the wait hint, but no less than 1 second and no more than 10 seconds
dwWaitTime = ssStatus.dwWaitHint / 10;
if( dwWaitTime < 1000 )
dwWaitTime = 1000;
else if ( dwWaitTime > 10000 )
dwWaitTime = 10000;
Sleep( dwWaitTime );
// Check the status again
if (!QueryServiceStatusEx(
schService, // handle to service
SC_STATUS_PROCESS_INFO, // info level
(LPBYTE) &ssStatus, // address of structure
sizeof(SERVICE_STATUS_PROCESS), // size of structure
&dwBytesNeeded ) ) // if buffer too small
{
wprintf(LQueryServiceStatusEx failed, error %d\n, GetLastError());
break;
}
if ( ssStatus.dwCheckPoint > dwOldCheckPoint )
{
// Continue to wait and check
dwStartTickCount = GetTickCount();
dwOldCheckPoint = ssStatus.dwCheckPoint;
}
else
{
if(GetTickCount()-dwStartTickCount > ssStatus.dwWaitHint)
{
// No progress made within the wait hint.
break;
}
}
}
// Determine whether the service is running
if (ssStatus.dwCurrentState == SERVICE_RUNNING)
{
wprintf(LService %s started successfully.\n, szSvcName);
}
else
{
wprintf(LService %s not started. \n, szSvcName);
wprintf(L Current State: %d\n, ssStatus.dwCurrentState);
wprintf(L Exit Code: %d\n, ssStatus.dwWin32ExitCode);
wprintf(L Check Point: %d\n, ssStatus.dwCheckPoint);
wprintf(L Wait Hint: %d\n, ssStatus.dwWaitHint);
}
CloseServiceHandle(schService);
CloseServiceHandle(schSCManager);
}
// Purpose:
// Updates the service DACL to grant start, stop, delete, and read
// control access to the Guest account.//
// Parameters: None
// Return value: None
VOID __stdcall DoUpdateSvcDacl()
{
EXPLICIT_ACCESS ea;
SECURITY_DESCRIPTOR sd;
PSECURITY_DESCRIPTOR psd = NULL;
PACL pacl = NULL;
PACL pNewAcl = NULL;
BOOL bDaclPresent = FALSE;
BOOL bDaclDefaulted = FALSE;
DWORD dwError = 0;
DWORD dwSize = 0;
DWORD dwBytesNeeded = 0;
// 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)
{
wprintf(LOpenSCManager() failed (%d)\n, GetLastError());
return;
}
// Get a handle to the service
schService = OpenService(
schSCManager, // SCManager database
szSvcName, // name of service
READ_CONTROL | WRITE_DAC); // access
if (schService == NULL)
{
wprintf(LOpenService() failed, error %d\n, GetLastError());
CloseServiceHandle(schSCManager);
return;
}
// Get the current security descriptor
if (!QueryServiceObjectSecurity(schService,
DACL_SECURITY_INFORMATION,
&psd, // using NULL does not work on all versions
0,
&dwBytesNeeded))
{
if (GetLastError() == ERROR_INSUFFICIENT_BUFFER)
{
dwSize = dwBytesNeeded;
psd = (PSECURITY_DESCRIPTOR)HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, dwSize);
if (psd == NULL)
{
// Note: HeapAlloc does not support GetLastError.
wprintf(LHeapAlloc failed!\n);
goto dacl_cleanup;
}
if (!QueryServiceObjectSecurity(schService, DACL_SECURITY_INFORMATION, psd, dwSize, &dwBytesNeeded))
{
wprintf(LQueryServiceObjectSecurity() failed, error %d\n, GetLastError());
goto dacl_cleanup;
}
}
else
{
wprintf(LQueryServiceObjectSecurity() failed %d\n, GetLastError());
goto dacl_cleanup;
}
}
// Get the DACL
if (!GetSecurityDescriptorDacl(psd, &bDaclPresent, &pacl, &bDaclDefaulted))
{
wprintf(LGetSecurityDescriptorDacl() failed, error %d\n, GetLastError());
goto dacl_cleanup;
}
// Build the ACE
BuildExplicitAccessWithName(&ea, LGUEST, SERVICE_START | SERVICE_STOP | READ_CONTROL | DELETE,
SET_ACCESS, NO_INHERITANCE);
dwError = SetEntriesInAcl(1, &ea, pacl, &pNewAcl);
if (dwError != ERROR_SUCCESS)
{
wprintf(LSetEntriesInAcl failed, error %d\n, dwError);
goto dacl_cleanup;
}
// Initialize a new security descriptor
if (!InitializeSecurityDescriptor(&sd, SECURITY_DESCRIPTOR_REVISION))
{
wprintf(LInitializeSecurityDescriptor failed, error %d\n, GetLastError());
goto dacl_cleanup;
}
// Set the new DACL in the security descriptor
if (!SetSecurityDescriptorDacl(&sd, TRUE, pNewAcl, FALSE))
{
wprintf(LSetSecurityDescriptorDacl failed, error %d\n, GetLastError());
goto dacl_cleanup;
}
// Set the new DACL for the service object
if (!SetServiceObjectSecurity(schService, DACL_SECURITY_INFORMATION, &sd))
{
wprintf(LSetServiceObjectSecurity failed, error %d\n, GetLastError());
goto dacl_cleanup;
}
else
wprintf(LService DACL updated successfully\n);
dacl_cleanup:
CloseServiceHandle(schSCManager);
CloseServiceHandle(schService);
if(NULL != pNewAcl)
LocalFree((HLOCAL)pNewAcl);
if(NULL != psd)
HeapFree(GetProcessHeap(), 0, (LPVOID)psd);
}
// Purpose: Stops the service.
// Parameters: None
// Return value: None
VOID __stdcall DoStopSvc()
{
SERVICE_STATUS_PROCESS ssp;
DWORD dwStartTime = GetTickCount();
DWORD dwBytesNeeded;
DWORD dwTimeout = 30000; // 30-second time-out
DWORD dwWaitTime;
// 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)
{
wprintf(LOpenSCManager failed, error %d\n, GetLastError());
return;
}
// Get a handle to the service
schService = OpenService(
schSCManager, // SCM database
szSvcName, // name of service
SERVICE_STOP |
SERVICE_QUERY_STATUS |
SERVICE_ENUMERATE_DEPENDENTS);
if (schService == NULL)
{
wprintf(LOpenService failed, error %d\n, GetLastError());
CloseServiceHandle(schSCManager);
return;
}
// Make sure the service is not already stopped
if ( !QueryServiceStatusEx(
schService,
SC_STATUS_PROCESS_INFO,
(LPBYTE)&ssp,
sizeof(SERVICE_STATUS_PROCESS),
&dwBytesNeeded ) )
{
wprintf(LQueryServiceStatusEx failed, error %d\n, GetLastError());
goto stop_cleanup;
}
if ( ssp.dwCurrentState == SERVICE_STOPPED )
{
wprintf(L%s service is already stopped.\n, szSvcName);
goto stop_cleanup;
}
// If a stop is pending, wait for it
while ( ssp.dwCurrentState == SERVICE_STOP_PENDING )
{
wprintf(L%s service stop pending...\n, szSvcName);
// Do not wait longer than the wait hint. A good interval is
// one-tenth of the wait hint but not less than 1 second
// and not more than 10 seconds
dwWaitTime = ssp.dwWaitHint / 10;
if( dwWaitTime < 1000 )
dwWaitTime = 1000;
else if ( dwWaitTime > 10000 )
dwWaitTime = 10000;
Sleep( dwWaitTime );
if ( !QueryServiceStatusEx(
schService,
SC_STATUS_PROCESS_INFO,
(LPBYTE)&ssp,
sizeof(SERVICE_STATUS_PROCESS),
&dwBytesNeeded ) )
{
wprintf(LQueryServiceStatusEx failed, error %d\n, GetLastError());
goto stop_cleanup;
}
if ( ssp.dwCurrentState == SERVICE_STOPPED )
{
wprintf(L%s service stopped successfully.\n, szSvcName);
goto stop_cleanup;
}
if ( GetTickCount() - dwStartTime > dwTimeout )
{
wprintf(LService stop timed out.\n);
goto stop_cleanup;
}
}
// If the service is running, dependencies must be stopped first
StopDependentServices();
// Send a stop code to the service
if ( !ControlService(schService, SERVICE_CONTROL_STOP, (LPSERVICE_STATUS) &ssp ) )
{
wprintf(LControlService failed, error %d\n, GetLastError() );
goto stop_cleanup;
}
// Wait for the service to stop
while ( ssp.dwCurrentState != SERVICE_STOPPED )
{
Sleep( ssp.dwWaitHint );
if ( !QueryServiceStatusEx(
schService,
SC_STATUS_PROCESS_INFO,
(LPBYTE)&ssp,
sizeof(SERVICE_STATUS_PROCESS),
&dwBytesNeeded ) )
{
wprintf(LQueryServiceStatusEx() failed, error %d\n, GetLastError() );
goto stop_cleanup;
}
if ( ssp.dwCurrentState == SERVICE_STOPPED )
break;
if ( GetTickCount() - dwStartTime > dwTimeout )
{
wprintf(LWait timed out...\n );
goto stop_cleanup;
}
}
wprintf(LService stopped successfully\n);
stop_cleanup:
CloseServiceHandle(schService);
CloseServiceHandle(schSCManager);
}
BOOL __stdcall StopDependentServices()
{
DWORD i;
DWORD dwBytesNeeded;
DWORD dwCount;
LPENUM_SERVICE_STATUS lpDependencies = NULL;
ENUM_SERVICE_STATUS ess;
SC_HANDLE hDepService;
SERVICE_STATUS_PROCESS ssp;
DWORD dwStartTime = GetTickCount();
DWORD dwTimeout = 30000; // 30-second time-out
// Pass a zero-length buffer to get the required buffer size.
if ( EnumDependentServices( schService, SERVICE_ACTIVE, lpDependencies, 0, &dwBytesNeeded, &dwCount ) )
{
// If the Enum call succeeds, then there are no dependent
// services, so do nothing.
return TRUE;
}
else
{
if ( GetLastError() != ERROR_MORE_DATA )
return FALSE; // Unexpected error
// Allocate a buffer for the dependencies.
lpDependencies = (LPENUM_SERVICE_STATUS) HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, dwBytesNeeded );
if ( !lpDependencies )
return FALSE;
__try {
// Enumerate the dependencies.
if ( !EnumDependentServices( schService, SERVICE_ACTIVE, lpDependencies, dwBytesNeeded, &dwBytesNeeded, &dwCount ) )
return FALSE;
for ( i = 0; i < dwCount; i++ )
{
ess = *(lpDependencies + i);
// Open the service.
hDepService = OpenService( schSCManager, ess.lpServiceName, SERVICE_STOP | SERVICE_QUERY_STATUS );
if ( !hDepService )
return FALSE;
__try {
// Send a stop code.
if ( !ControlService( hDepService, SERVICE_CONTROL_STOP, (LPSERVICE_STATUS) &ssp ) )
return FALSE;
// Wait for the service to stop.
while ( ssp.dwCurrentState != SERVICE_STOPPED )
{
Sleep( ssp.dwWaitHint );
if ( !QueryServiceStatusEx(
hDepService,
SC_STATUS_PROCESS_INFO,
(LPBYTE)&ssp,
sizeof(SERVICE_STATUS_PROCESS),
&dwBytesNeeded ) )
return FALSE;
if ( ssp.dwCurrentState == SERVICE_STOPPED )
break;
if ( GetTickCount() - dwStartTime > dwTimeout )
return FALSE;
}
}
__finally
{
// Always release the service handle.
CloseServiceHandle( hDepService );
}
}
}
__finally
{
// Always free the enumeration buffer.
HeapFree( GetProcessHeap(), 0, lpDependencies );
}
}
return TRUE;
}
Build this project independently. Make sure there is no error.
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