Como efectuar ping a um endereço IP com o Visual Basic utilizando ICMP

Sumário

Este artigo passo-a-passo descreve como efectuar o ping a um endereço IP (Internet Protocol) remoto utilizando o Visual Basic 6.0 e o ficheiro Icmp.dll.

Utilizar o ICMP para efectuar um ping no Visual Basic

  1. Inicie o Microsoft Visual Basic 6.0.
  2. Na caixa de diálogo New Project, clique em Standard EXE e, em seguida, clique em Open. O Visual Basic Design Editor é aberto e o Form1 é carregado.
  3. Para adicionar um novo módulo a este projecto, clique com o botão direito do rato em Project1.vbp no Project Explorer, aponte para Add e, em seguida, clique em Module.
  4. Na caixa de diálogo Add Module, clique em Open. O módulo Module1.bas é adicionado ao projecto e é aberto na janela Code Editor.
  5. Na parte superior da janela Code Editor do Module1, adicione as seguintes constantes e declaração de função:
    Option Explicit

    'Icmp constants converted from
    'http://msdn.microsoft.com/library/default.asp?url=/library/en-us/wmisdk/wmi/win32_pingstatus.asp

    Private Const ICMP_SUCCESS As Long = 0
    Private Const ICMP_STATUS_BUFFER_TO_SMALL = 11001 'Buffer Too Small
    Private Const ICMP_STATUS_DESTINATION_NET_UNREACH = 11002 'Destination Net Unreachable
    Private Const ICMP_STATUS_DESTINATION_HOST_UNREACH = 11003 'Destination Host Unreachable
    Private Const ICMP_STATUS_DESTINATION_PROTOCOL_UNREACH = 11004 'Destination Protocol Unreachable
    Private Const ICMP_STATUS_DESTINATION_PORT_UNREACH = 11005 'Destination Port Unreachable
    Private Const ICMP_STATUS_NO_RESOURCE = 11006 'No Resources
    Private Const ICMP_STATUS_BAD_OPTION = 11007 'Bad Option
    Private Const ICMP_STATUS_HARDWARE_ERROR = 11008 'Hardware Error
    Private Const ICMP_STATUS_LARGE_PACKET = 11009 'Packet Too Big
    Private Const ICMP_STATUS_REQUEST_TIMED_OUT = 11010 'Request Timed Out
    Private Const ICMP_STATUS_BAD_REQUEST = 11011 'Bad Request
    Private Const ICMP_STATUS_BAD_ROUTE = 11012 'Bad Route
    Private Const ICMP_STATUS_TTL_EXPIRED_TRANSIT = 11013 'TimeToLive Expired Transit
    Private Const ICMP_STATUS_TTL_EXPIRED_REASSEMBLY = 11014 'TimeToLive Expired Reassembly
    Private Const ICMP_STATUS_PARAMETER = 11015 'Parameter Problem
    Private Const ICMP_STATUS_SOURCE_QUENCH = 11016 'Source Quench
    Private Const ICMP_STATUS_OPTION_TOO_BIG = 11017 'Option Too Big
    Private Const ICMP_STATUS_BAD_DESTINATION = 11018 'Bad Destination
    Private Const ICMP_STATUS_NEGOTIATING_IPSEC = 11032 'Negotiating IPSEC
    Private Const ICMP_STATUS_GENERAL_FAILURE = 11050 'General Failure

    Public Const WINSOCK_ERROR = "Windows Sockets not responding correctly."
    Public Const INADDR_NONE As Long = &HFFFFFFFF
    Public Const WSA_SUCCESS = 0
    Public Const WS_VERSION_REQD As Long = &H101

    'Clean up sockets.
    'http://support.microsoft.com/default.aspx?scid=kb;EN-US;q154512

    Private Declare Function WSACleanup Lib "WSOCK32.DLL" () As Long

    'Open the socket connection.
    'http://support.microsoft.com/default.aspx?scid=kb;EN-US;q154512
    Private Declare Function WSAStartup Lib "WSOCK32.DLL" (ByVal wVersionRequired As Long, lpWSADATA As WSADATA) As Long

    'Create a handle on which Internet Control Message Protocol (ICMP) requests can be issued.
    'http://msdn.microsoft.com/library/default.asp?url=/library/en-us/wcesdkr/htm/_wcesdk_icmpcreatefile.asp
    Private Declare Function IcmpCreateFile Lib "icmp.dll" () As Long

    'Convert a string that contains an (Ipv4) Internet Protocol dotted address into a correct address.
    'http://msdn.microsoft.com/library/default.asp?url=/library/en-us/winsock/wsapiref_4esy.asp
    Private Declare Function inet_addr Lib "WSOCK32.DLL" (ByVal cp As String) As Long

    'Close an Internet Control Message Protocol (ICMP) handle that IcmpCreateFile opens.
    'http://msdn.microsoft.com/library/default.asp?url=/library/en-us/wcesdkr/htm/_wcesdk_icmpclosehandle.asp

    Private Declare Function IcmpCloseHandle Lib "icmp.dll" (ByVal IcmpHandle As Long) As Long

    'Information about the Windows Sockets implementation
    'http://support.microsoft.com/default.aspx?scid=kb;EN-US;q154512
    Private Type WSADATA
    wVersion As Integer
    wHighVersion As Integer
    szDescription(0 To 256) As Byte
    szSystemStatus(0 To 128) As Byte
    iMaxSockets As Long
    iMaxUDPDG As Long
    lpVendorInfo As Long
    End Type

    'Send an Internet Control Message Protocol (ICMP) echo request, and then return one or more replies.
    'http://msdn.microsoft.com/library/default.asp?url=/library/en-us/wcetcpip/htm/cerefIcmpSendEcho.asp
    Private Declare Function IcmpSendEcho Lib "icmp.dll" _
    (ByVal IcmpHandle As Long, _
    ByVal DestinationAddress As Long, _
    ByVal RequestData As String, _
    ByVal RequestSize As Long, _
    ByVal RequestOptions As Long, _
    ReplyBuffer As ICMP_ECHO_REPLY, _
    ByVal ReplySize As Long, _
    ByVal Timeout As Long) As Long

    'This structure describes the options that will be included in the header of an IP packet.
    'http://msdn.microsoft.com/library/default.asp?url=/library/en-us/wcetcpip/htm/cerefIP_OPTION_INFORMATION.asp
    Private Type IP_OPTION_INFORMATION
    Ttl As Byte
    Tos As Byte
    Flags As Byte
    OptionsSize As Byte
    OptionsData As Long
    End Type

    'This structure describes the data that is returned in response to an echo request.
    'http://msdn.microsoft.com/library/default.asp?url=/library/en-us/wcesdkr/htm/_wcesdk_icmp_echo_reply.asp
    Public Type ICMP_ECHO_REPLY
    address As Long
    Status As Long
    RoundTripTime As Long
    DataSize As Long
    Reserved As Integer
    ptrData As Long
    Options As IP_OPTION_INFORMATION
    Data As String * 250
    End Type

    '-- Ping a string representation of an IP address.
    ' -- Return a reply.
    ' -- Return long code.
    Public Function ping(sAddress As String, Reply As ICMP_ECHO_REPLY) As Long

    Dim hIcmp As Long
    Dim lAddress As Long
    Dim lTimeOut As Long
    Dim StringToSend As String

    'Short string of data to send
    StringToSend = "hello"

    'ICMP (ping) timeout
    lTimeOut = 1000 'ms

    'Convert string address to a long representation.
    lAddress = inet_addr(sAddress)

    If (lAddress <> -1) And (lAddress <> 0) Then

    'Create the handle for ICMP requests.
    hIcmp = IcmpCreateFile()

    If hIcmp Then
    'Ping the destination IP address.
    Call IcmpSendEcho(hIcmp, lAddress, StringToSend, Len(StringToSend), 0, Reply, Len(Reply), lTimeOut)

    'Reply status
    ping = Reply.Status

    'Close the Icmp handle.
    IcmpCloseHandle hIcmp
    Else
    Debug.Print "failure opening icmp handle."
    ping = -1
    End If
    Else
    ping = -1
    End If

    End Function

    'Clean up the sockets.
    'http://support.microsoft.com/default.aspx?scid=kb;EN-US;q154512
    Public Sub SocketsCleanup()

    WSACleanup

    End Sub

    'Get the sockets ready.
    'http://support.microsoft.com/default.aspx?scid=kb;EN-US;q154512
    Public Function SocketsInitialize() As Boolean

    Dim WSAD As WSADATA

    SocketsInitialize = WSAStartup(WS_VERSION_REQD, WSAD) = ICMP_SUCCESS

    End Function

    'Convert the ping response to a message that you can read easily from constants.
    'For more information about these constants, visit the following Microsoft Web site:
    'http://msdn.microsoft.com/library/default.asp?url=/library/en-us/wmisdk/wmi/win32_pingstatus.asp

    Public Function EvaluatePingResponse(PingResponse As Long) As String

    Select Case PingResponse

    'Success
    Case ICMP_SUCCESS: EvaluatePingResponse = "Success!"

    'Some error occurred
    Case ICMP_STATUS_BUFFER_TO_SMALL: EvaluatePingResponse = "Buffer Too Small"
    Case ICMP_STATUS_DESTINATION_NET_UNREACH: EvaluatePingResponse = "Destination Net Unreachable"
    Case ICMP_STATUS_DESTINATION_HOST_UNREACH: EvaluatePingResponse = "Destination Host Unreachable"
    Case ICMP_STATUS_DESTINATION_PROTOCOL_UNREACH: EvaluatePingResponse = "Destination Protocol Unreachable"
    Case ICMP_STATUS_DESTINATION_PORT_UNREACH: EvaluatePingResponse = "Destination Port Unreachable"
    Case ICMP_STATUS_NO_RESOURCE: EvaluatePingResponse = "No Resources"
    Case ICMP_STATUS_BAD_OPTION: EvaluatePingResponse = "Bad Option"
    Case ICMP_STATUS_HARDWARE_ERROR: EvaluatePingResponse = "Hardware Error"
    Case ICMP_STATUS_LARGE_PACKET: EvaluatePingResponse = "Packet Too Big"
    Case ICMP_STATUS_REQUEST_TIMED_OUT: EvaluatePingResponse = "Request Timed Out"
    Case ICMP_STATUS_BAD_REQUEST: EvaluatePingResponse = "Bad Request"
    Case ICMP_STATUS_BAD_ROUTE: EvaluatePingResponse = "Bad Route"
    Case ICMP_STATUS_TTL_EXPIRED_TRANSIT: EvaluatePingResponse = "TimeToLive Expired Transit"
    Case ICMP_STATUS_TTL_EXPIRED_REASSEMBLY: EvaluatePingResponse = "TimeToLive Expired Reassembly"
    Case ICMP_STATUS_PARAMETER: EvaluatePingResponse = "Parameter Problem"
    Case ICMP_STATUS_SOURCE_QUENCH: EvaluatePingResponse = "Source Quench"
    Case ICMP_STATUS_OPTION_TOO_BIG: EvaluatePingResponse = "Option Too Big"
    Case ICMP_STATUS_BAD_DESTINATION: EvaluatePingResponse = "Bad Destination"
    Case ICMP_STATUS_NEGOTIATING_IPSEC: EvaluatePingResponse = "Negotiating IPSEC"
    Case ICMP_STATUS_GENERAL_FAILURE: EvaluatePingResponse = "General Failure"

    'Unknown error occurred
    Case Else: EvaluatePingResponse = "Unknown Response"

    End Select

    End Function
    Nota Tome cuidado com a moldagem de texto quando copiar este código para o projecto. Este código fornece as funções para aceder ao ficheiro Icmp.dll. Consulte os comentários inline para obter uma descrição das constantes, declarações e chamadas de função.
  6. No Project Explorer, clique com o botão direito do rato em Form1 e, em seguida, clique em View Object. O Form1 é carregado na janela Designer.
  7. Faça duplo clique no corpo de Form1. A janela Code Editor é aberta com o código seguinte:
    Private Sub Form_Load()

    End Sub
  8. Substitua o código existente no método Form_Load pelo código seguinte:
    Private Sub Form_Load()

    Dim Reply As ICMP_ECHO_REPLY
    Dim lngSuccess As Long
    Dim strIPAddress As String

    'Get the sockets ready.
    If SocketsInitialize() Then

    'Address to ping
    strIPAddress = "192.168.1.1"

    'Ping the IP that is passing the address and get a reply.
    lngSuccess = ping(strIPAddress, Reply)

    'Display the results.
    Debug.Print "Address to Ping: " & strIPAddress
    Debug.Print "Raw ICMP code: " & lngSuccess
    Debug.Print "Ping Response Message : " & EvaluatePingResponse(lngSuccess)
    Debug.Print "Time : " & Reply.RoundTripTime & " ms"

    'Clean up the sockets.
    SocketsCleanup

    Else

    'Winsock error failure, initializing the sockets.
    Debug.Print WINSOCK_ERROR

    End If

    End Sub
  9. Localize as seguintes linhas de código:
        'Address to ping
    strIPAddress = "192.168.1.1"
    Altere o strIPAddress para o endereço IP ao qual pretenda efectuar o ping.
  10. Para guardar o projecto e os ficheiros associados, clique em Save Project no menu File.
  11. Note que os resultados do código são escritos na janela Immediate. Para verificar se a janela Immediate está aberta, clique em Immediate Window no menu View.
  12. Para testar este código, prima F5. Os resultados são apresentados na janela Immediate. Os resultados são semelhantes aos seguintes:

    Address to Ping: 192.168.1.1
    Raw ICMP code: 0
    Ping Response Message : Success!
    Time : 10 ms
Nota Para efectuar ping a um nome de domínio, tem de o converter primeiro num endereço.

Para obter mais informações, clique no número de artigo que se segue para visualizar o artigo na Base de Dados de Conhecimento Microsoft:

154512 SAMPLE: Winsock.exe getting HostAddress by using Windows Sockets

Propriedades

ID do Artigo: 300197 - Última Revisão: 28/12/2007 - Revisão: 1

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