Thread: remote execution COM DCOM?

> and does that have anything to do with COM/DCOM...
I think you could use those for this purpose, but it's not necessary to use them.

The first thing you need is to get a copy of myProcess2.exe onto the remote machine.

Then you need some kind of server program running on the slave machine, which can listen for remote instructions. One of those remote instructions (which the master will send) is "run executable.exe".

There's lots of information in the sticky threads of this forum to help with the low level send and receive over a network.

You may want to check out the DispHelper COM Helper Library. In the wmi.cpp sample file (or wmi.c if you prefer C) you will find a function called StartProcess that can be used to start a process on the local or remote computer. It takes a computer name and a program path. You must have administrator priviliges on the remote computer.

Another option is Sysinternals' PsExec.

I'm not sure this will be useful as it is a vbscript rather than C/C++. However, it does exactly what you want. It copies a selected file to the remote computer, executes a command line and returns the result. Copy the code to a text file and name it StartRemote.vbs.

Code:

'/* ---------------------------------------------------------------- */'
Sub PrepareRemote(szComputer, szFile, szCmdLine)

	Set fso = CreateObject("Scripting.FileSystemObject")

	szRemotePath = "\\" & szComputer & "\c$\___temp___\" 

	If (Not fso.FolderExists(szRemotePath)) Then
		Set f = fso.CreateFolder(szRemotePath)
		f.Attributes = f.Attributes Or 2 Or 4 'Hidden and System
	End If

	If (szFile <> "" And _
	    Not fso.FileExists(szRemotePath & fso.GetFileName(szFile))) Then
		  fso.CopyFile szFile, szRemotePath & fso.GetFileName(szFile)
	End If

	Set strm = fso.CreateTextFile(szRemotePath & "run.bat", True)

	strm.WriteLine "CALL " & szCmdLine

	strm.WriteLine "ECHO %ERRORLEVEL% > C:\___temp___\result.txt"

	strm.Close
End Sub


'/* ---------------------------------------------------------------- */'
Function ReadResult(szComputer, bCleanup)

	Set fso = CreateObject("Scripting.FileSystemObject")

	szRemotePath = "\\" & szComputer & "\c$\___temp___"

	Set strm = fso.OpenTextFile(szRemotePath & "\result.txt")

	ReadResult = strm.ReadAll()

	strm.Close

	If (bCleanup) Then fso.DeleteFolder(szRemotePath)
End Function


'/* ---------------------------------------------------------------- */'
Function StartProcess(szComputer, szCmdLine)

	szWmiStr = "winmgmts:{impersonationLevel=impersonate}!\\" & _
	              szComputer & "\root\cimv2"

	szWmiStr = szWmiStr & ":Win32_Process"

	Set wmiProcess = GetObject(szWmiStr)

	nResult = wmiProcess.Create(szCmdLine,,,pid)

	If (nResult <> 0) Then
		Err.Raise nResult, "Win32_Process::Create", _
		          "Failed to create remote process."
	End If

	StartProcess = pid
End Function


'/* ---------------------------------------------------------------- */'
Sub WaitForTermination(szComputer, pid)

	szWmiStr = "winmgmts:{impersonationLevel=impersonate}!\\" & _
	              szComputer & "\root\cimv2"
	
	Set wmiSvc = GetObject(szWmiStr)

	Set wmiEventSrc = wmiSvc.ExecNotificationQuery( _
	           "SELECT * FROM __InstanceDeletionEvent WITHIN 1 " & _
	           "WHERE TargetInstance ISA 'Win32_Process' AND "   & _
	           "TargetInstance.ProcessId=" & pid)

	wmiEventSrc.NextEvent
End Sub


'/* ---------------------------------------------------------------- */'
Function StartRemoteProcess(szComputer, szFilePath, szCmdLine, bCleanup)

	Call PrepareRemote(szComputer, szFilePath, szCmdLine)

	pid = StartProcess(szComputer, "C:\___temp___\run.bat")

	Call WaitForTermination(szComputer, pid)

	StartRemoteProcess = ReadResult(szComputer, bCleanup)
End Function

'' Sample usages (shows pushing out windows updates).

' Vulnerability in the Microsoft Jet Database Engine Could Allow Code Execution (837001)
'MsgBox "The result of running the remote program was " & _
'       StartRemoteProcess("remote_computer", "C:\Documents and Settings\UONE\Desktop\Windows2000-KB837001-x86-ENU.EXE", _
'       "C:\___temp___\Windows2000-KB837001-x86-ENU.EXE /passive /quiet /norestart /o", False)

' Cumulative Update for Microsoft RPC/DCOM (828741)
'MsgBox "The result of running the remote program was " & _
'       StartRemoteProcess("remote_computer", "C:\Documents and Settings\UONE\Desktop\Windows2000-KB828741-x86-ENU.EXE", _
'       "C:\___temp___\Windows2000-KB828741-x86-ENU.EXE /passive /quiet /norestart /o", False)

Note: Both this and the DispHelper based solution will only run on Windows 2000/XP.