Find Device on LAN

[chris stroud]

I am on a roll, one thread every night! (this isn't my goal) Anyway, I was wondering if it is possible to look on the Local Area Network you are connected to, and create a list of attached devices. Kinda like logging into your router to view the attached devices, only doing it in VB. Is this possible? All i need to get is the name it Identifies itself as and it's IP address. (not a malware app of any kind) Thanks!

[RobDog888]

Like this?

http://vbforums.com/showpost.php?p=1801390&postcount=6

[chris stroud]

Honestly, to a noob that looks like Spanish, but I will try it and see what I can get. I hope that will work. What should I do to use the code? just add it to a form and have 2 combo boxes? Thanks!

[RobDog888]

The notes are in the comments. Just add the first part of the code to a module and then where the comments state "Behind a form" you place that code behind a form. it will duplicate a network neighborhood listing all computers on your LAN.

[chris stroud]

The notes are in the comments. Just add the first part of the code to a module and then where the comments state "Behind a form" you place that code behind a form. it will duplicate a network neighborhood listing all computers on your LAN.

That is great! Will it reveal their IP addresses too?

[RobDog888]

No, but you can just write another function to ping the retrieved computer domain/name to get its IP addy.
Then rinse and repeat for each found computer

[chris stroud]

No, but you can just write another function to ping the retrieved computer domain/name to get its IP addy.
Then rinse and repeat for each found computer

Sounds good, but I might have to ask for help with that later on... because I know the terminology of what you said... just not how to code it Thanks for your help!

[RobDog888]

Its not too hard you just need to use some winsock APIs to do it. If you search GetHostByName and IcmpSendEcho you should find examples or I can write one up if you want.

[chris stroud]

If it isn't too much to bother you with, I would really appreciate that. I learn alot from the Sample code you guys give me, but I'm new to developing on the Windows Platform entirely (I'm probably the only Mac Boy in here ) Thank you so much. I know about 2,000 people that are going to appreciate this and not even know it!

[RobDog888]

I made an example Its a quick and dirty one as there isnt enough/complete error checking but should get your started.

Option Explicit
'Add 2 labels, 2 textboxes and 1 command button.

Private Const MIN_SOCKETS_REQD = 1
Private Const WSADescription_Len = 256
Private Const WSASYS_Status_Len = 128

Const SOCKET_ERROR = 0

Private Type WSAdata
    wVersion As Integer
    wHighVersion As Integer
    szDescription(0 To 255) As Byte
    szSystemStatus(0 To 128) As Byte
    iMaxSockets As Integer
    iMaxUdpDg As Integer
    lpVendorInfo As Long
End Type

Private Type Hostent
    h_name As Long
    h_aliases As Long
    h_addrtype As Integer
    h_length As Integer
    h_addr_list As Long
End Type

Private Type IP_OPTION_INFORMATION
    TTL As Byte
    Tos As Byte
    flags As Byte
    OptionsSize As Long
    OptionsData As String * 128
End Type

Private Type IP_ECHO_REPLY
    Address(0 To 3) As Byte
    Status As Long
    RoundTripTime As Long
    DataSize As Integer
    Reserved As Integer
    data As Long
    Options As IP_OPTION_INFORMATION
End Type

Private Declare Function GetHostByName Lib "wsock32.dll" Alias "gethostbyname" (ByVal HostName As String) As Long

Private Declare Function WSAStartup Lib "wsock32.dll" (ByVal wVersionRequired&, lpWSAdata As WSAdata) As Long

Private Declare Function WSACleanup Lib "wsock32.dll" () As Long

Private Declare Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" (hpvDest As Any, hpvSource As Any, ByVal cbCopy As Long)

Private Declare Function IcmpCreateFile Lib "icmp.dll" () As Long

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

Private Declare Function IcmpSendEcho Lib "ICMP" (ByVal IcmpHandle As Long, ByVal DestAddress As Long, _
ByVal RequestData As String, ByVal RequestSize As Integer, RequestOptns As IP_OPTION_INFORMATION, ReplyBuffer As IP_ECHO_REPLY, _
ByVal ReplySize As Long, ByVal TimeOut As Long) As Boolean

Private Sub Command1_Click()
    CheckComputerStatus Text1.Text
End Sub

Private Sub Form_Load()
    Me.Width = 5000
    Me.Height = 2000
    Text1.Text = vbNullString
    Text2.Text = vbNullString
    Label1.Move 60, 120, 2000, 255
    Label2.Move 60 + Label1.Width + 60, 120, 2500, 255
    Text1.Move 60, Label1.Top + Label1.Height + 60, 2000, 315
    Text2.Move 60 + Label1.Width + 60, Label2.Top + Label2.Height + 60, 2500, 315
    Command1.Caption = "Ping Me"
    Command1.Height = 315
    Command1.Width = 1155
    Command1.Move Me.ScaleWidth - Command1.Width - 60, Me.ScaleHeight - 60 - Command1.Height
End Sub

Private Function CheckComputerStatus(ByVal HostName As String) As Boolean

    On Error GoTo My_Error
    
    Dim hostent_addr As Long
    Dim host As Hostent
    Dim hostip_addr As Long
    Dim temp_ip_address() As Byte
    Dim i As Integer
    Dim ip_address As String
    
    Dim hFile As Long, lpWSAdata As WSAdata
    Dim hHostent As Hostent, AddrList As Long
    Dim Address As Long, rIP As String
    Dim OptInfo As IP_OPTION_INFORMATION
    Dim EchoReply As IP_ECHO_REPLY
    Dim bRetVal As Boolean
    
    Me.Text2.Text = "Status: Checking..."
    DoEvents
    'GET HOST NAME
    Call WSAStartup(&H101, lpWSAdata)
    If GetHostByName(HostName + String(64 - Len(HostName), 0)) <> SOCKET_ERROR Then
        CopyMemory hHostent.h_name, ByVal GetHostByName(HostName + String(64 - Len(HostName), 0)), Len(hHostent)
        CopyMemory AddrList, ByVal hHostent.h_addr_list, 4
        CopyMemory Address, ByVal AddrList, 4
        hFile = IcmpCreateFile()
        If hFile <> 0 Then
            'PING COMPUTER
            OptInfo.TTL = 255
            bRetVal = IcmpSendEcho(hFile, Address, String(32, "A"), 32, OptInfo, EchoReply, Len(EchoReply) + 8, 2000)
            If (bRetVal) Then
                rIP = CStr(EchoReply.Address(0)) + "." + CStr(EchoReply.Address(1)) + "." + CStr(EchoReply.Address(2)) + "." + CStr(EchoReply.Address(3))
            End If
            If EchoReply.Status = 0 Then
                Me.Text2.Text = HostName + " (" + rIP + ") " + Trim$(CStr(EchoReply.RoundTripTime)) + "ms"
            End If
        End If
        CheckComputerStatus = True
    End If
    Call IcmpCloseHandle(hFile)
    Call WSACleanup
    Exit Function
My_Error:
    Me.Text2.Text = "Ping timeout"
End Function

[chris stroud]

Thanks, I'll give it a whirl today. You guys are awesome!

[RobDog888]

There probably are other ways that would be faster like if you are in a Active Directory network then you could query the AD database etc but without knowing more of your networks config I would have to go with this.

[chris stroud]

There probably are other ways that would be faster like if you are in a Active Directory network then you could query the AD database etc but without knowing more of your networks config I would have to go with this.

Well, it will have to be compatible with most every home networks... I think it will work. I'm about to test as soon as I finish this one project in about 2hrs. Thanks Again!

[RobDog888]

Yea winsock32.dll and icmp.dll together require Windows Sockets 2.0 so it should work on almost any system.

no prob.

[chris stroud]

I finally finished debugging my other app and I got to test this code out... it works for all of the computers in my network, but unfortunately it doesn't seem to identify anything BUT computers... I actually really need it to target iPhones and iPod touch's I'm not sure what the difference in coding would be, or perhaps I'm doing it wrong, but I like what you gave me, it's pretty nifty and I think if I have a little guidance on how to modify it, it will work wonderfully. Thanks for all your hard work!

[Edgemeal]

iPhones & iPods plug into LAN? I thought they'd be USB devices?

[chris stroud]

they are USB devices, but they have WiFi capability. When they are jailbroken, they can do much more. I just need to make a small utility to help find say.. an iPhone on your network and get it's IP. This would be to avoid logging into your router... which is a long process

[RobDog888]

Ah then that may be a different process. Im not familiar with mobile programming.

[chris stroud]

Well, I would think that it would be close... Can we just populate a list of all devices attached to the network? it may not be that simple, but they are just like any other device that requests an IP address etc... it supports WEP encryption and several others. I wouldn't think it's that hard, but it might be in VB idk.