CreateProcess و NSLOOKUP غريب

Question

لدي روتين API هذا الذي أستخدمه بانتظام لالتقاط إخراج DOS. في الآونة الأخيرة ، تم العثور على خطأ غريب حيث لا يبدو أنه يسمح لمكالمات DNS. على سبيل المثال ، ستعيد NSLookup خطأ "لا استجابة من الخادم" مع الخادم: غير معروف. ستعمل Ping إذا قمت بتوفير عنوان IP ، ولكن ليس إذا كان عليها إجراء مكالمة DNS. هذه المشكلة معزولة تمامًا لهذا الرمز.

أي نظرة ثاقبة لهذه المشكلة سيكون موضع تقدير. وينابي ليس أقوى منطقة لي.

تحرير: آسف لإضافة جميع الثوابت والأنواع ، لكنني جعلت هذا في شيء يمكنك لصقه في وحدة نمطية والتشغيل للاختبار لنفسك في محاولة لجعل المشكلة أسهل في حلها.

' STARTUPINFO flags
Private Const STARTF_USESHOWWINDOW = &H1
Private Const STARTF_USESTDHANDLES = &H100

' ShowWindow flag
Private Const SW_HIDE = 0

'CreatePipe buffer size
Private Const BUFSIZE = 1024

Private Type SECURITY_ATTRIBUTES
    nLength As Long
    lpSecurityDescriptor As Long
    bInheritHandle As Long
End Type

Private Type STARTUPINFO
    cb As Long
    lpReserved As Long
    lpDesktop As Long
    lpTitle As Long
    dwX As Long
    dwY As Long
    dwXSize As Long
    dwYSize As Long
    dwXCountChars As Long
    dwYCountChars As Long
    dwFillAttribute As Long
    dwFlags As Long
    wShowWindow As Integer
    cbReserved2 As Integer
    lpReserved2 As Long
    hStdInput As Long
    hStdOutput As Long
    hStdError As Long
End Type

Private Type PROCESS_INFORMATION
    hProcess As Long
    hThread As Long
    dwProcessId As Long
    dwThreadId As Long
End Type

Private Declare Function CloseHandle Lib "kernel32.dll" (ByVal hObject As Long) As Long
Private Declare Function CreatePipe Lib "kernel32.dll" (ByRef phReadPipe As Long, ByRef phWritePipe As Long, ByRef lpPipeAttributes As SECURITY_ATTRIBUTES, ByVal nSize As Long) As Long
Private Declare Function CreateProcess Lib "kernel32.dll" Alias "CreateProcessA" (ByVal lpApplicationName As String, ByVal lpCommandLine As String, ByRef lpProcessAttributes As SECURITY_ATTRIBUTES, ByRef lpThreadAttributes As SECURITY_ATTRIBUTES, ByVal bInheritHandles As Long, ByVal dwCreationFlags As Long, ByRef lpEnvironment As Any, ByVal lpCurrentDriectory As String, ByRef lpStartupInfo As STARTUPINFO, ByRef lpProcessInformation As PROCESS_INFORMATION) As Long
Private Declare Sub GetStartupInfo Lib "kernel32.dll" Alias "GetStartupInfoA" (ByRef lpStartupInfo As STARTUPINFO)
Private Declare Function PeekNamedPipe Lib "kernel32.dll" (ByVal hNamedPipe As Long, ByRef lpBuffer As Any, ByVal nBufferSize As Long, ByRef lpBytesRead As Long, ByRef lpTotalBytesAvail As Long, ByRef lpBytesLeftThisMessage As Long) As Long
Private Declare Function ReadFile Lib "kernel32" (ByVal hFile As Long, ByVal lpBuffer As String, ByVal nNumberOfBytesToRead As Long, lpNumberOfBytesRead As Long, lpOverlapped As Any) As Long

Sub CreateprocessApiTest()
    On Error GoTo errHandler
    Dim pa As SECURITY_ATTRIBUTES
    Dim pra As SECURITY_ATTRIBUTES
    Dim tra As SECURITY_ATTRIBUTES
    Dim si As STARTUPINFO
    Dim pi As PROCESS_INFORMATION
    Dim retVal As Long
    Dim command As String
    Dim ErrorDesc As String
    Dim hRead As Long     ' stdout + stderr
    Dim hWrite As Long
    Dim bAvail As Long    ' pipe bytes available (PeekNamedPipe)
    Dim bRead As Long     ' pipe bytes fetched   (ReadFile)
    Dim bString As String    ' our buffer
    Dim s As String

    command = "nslookup google.com"

    pa.nLength = Len(pa)
    pa.bInheritHandle = 1

    pra.nLength = Len(pra)
    tra.nLength = Len(tra)

    retVal = CreatePipe(hRead, hWrite, pa, BUFSIZE)

    With si
        .cb = Len(si)
        GetStartupInfo si
        .dwFlags = STARTF_USESHOWWINDOW Or STARTF_USESTDHANDLES
        .wShowWindow = SW_HIDE
        .hStdOutput = hWrite
        .hStdError = hWrite
    End With

    retVal = CreateProcess(vbNullString, command, pra, tra, 1, 0&, 0&, vbNullString, si, pi)

    Do While PeekNamedPipe(hRead, ByVal 0, 0, ByVal 0, bAvail, ByVal 0)
        DoEvents
        If bAvail Then
            bString = String(bAvail, 0)
            ReadFile hRead, bString, bAvail, bRead, ByVal 0&
            bString = Left(bString, bRead)
            s = s & bString
            CloseHandle hWrite
        End If
    Loop
    CloseHandle hRead
    CloseHandle pi.hThread
    CloseHandle pi.hProcess

    MsgBox s

exitRoutine:
    Exit Sub
errHandler:
    Debug.Print Err.Number, Err.Description
    Resume exitRoutine
End Sub

Answer 1

خاطئ lpEnvironment As Any معامل. يضيف ByVal مثله

retVal = CreateProcess(vbNullString, command, pra, tra, 1, 0&, ByVal 0&, vbNullString, si, pi)