Xenophobic packet analyzer that only analyze its own frames

[AntoineS]

Good morning!

I'm trying to code my own packet analyser in VB.NET, it works by pressing a start button and chosing the connection to put into a datagridbox.

Yet I have two issues, one of form and the other of substance. It seems that my packet anlayzer is xenophobic, it doesn't accept other frames than his own one, and he doesn't want to store more than one frame at a given time.

• On the substance I can't access to other frames than those which came from my computer to my computer despite of the fact that an Ethernet camera is wired to my computer through an Ethernet cable
• On the form, all my frames disappears when a new one (which creates a new line) appear to my array.

Can you help me finding the criminal that impedes those frames to come and to live?

Here is my code:

Imports System.Net
Imports System.Net.Sockets
 
 
 
Public Class Form1
 
    Dim mycomputerconnections() As Net.NetworkInformation.NetworkInterface 'I don't know what it is...
    Dim monip As IPAddress
    Dim socket As New Socket(AddressFamily.InterNetwork, SocketType.Raw, ProtocolType.IP)
    Dim buffer(4096) As Byte
    Dim destinationport As UInteger
    Dim sourceport As UInteger
    Dim typez As String
    Dim sizediff As Size
    Dim formloaded As Boolean = False
    Private ipfrom As IPAddress
    Private ipto As IPAddress
    Private FilterIP As Boolean = False
    Private stringz As String = ""
    Private started As Boolean = False
 
    Private Sub DémarrageAquisitionToolStripMenuItem_Click(sender As Object, e As EventArgs) Handles DémarrageAquisitionToolStripMenuItem.Click
 
    End Sub
 
    Private Sub QuitterToolStripMenuItem_Click(sender As Object, e As EventArgs) Handles QuitterToolStripMenuItem.Click
        End
 
    End Sub
 
 
    Private Sub affichage_trame_ip_TextChanged(sender As Object, e As EventArgs) Handles affichage_trame_ip.TextChanged
 
    End Sub
 
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
 
        sizediff.Height = Me.Height - DataGridView1.Height
 
        sizediff.Width = Me.Width - DataGridView1.Width
 
        formloaded = True
 
        mycomputerconnections = Net.NetworkInformation.NetworkInterface.GetAllNetworkInterfaces
 
        For i = 0 To mycomputerconnections.Length - 1
 
            ComboBox1.Items.Add(mycomputerconnections(i).Name)
 
        Next
 
 
 
    End Sub
 
    Private Sub ComboBox1_SelectedIndexChanged(sender As Object, e As EventArgs) Handles ComboBox1.SelectedIndexChanged
 
        'Récupération de l'adresse IP et appel de la méthode d'association de la socket avec un point de terminaison local (un port).
 
        For i = 0 To mycomputerconnections(ComboBox1.SelectedIndex).GetIPProperties.UnicastAddresses.Count - 1 'what foes GetIPProperties mean?
 
            If mycomputerconnections(ComboBox1.SelectedIndex).GetIPProperties.UnicastAddresses(i).Address.AddressFamily = Net.Sockets.AddressFamily.InterNetwork Then
 
                monip = mycomputerconnections(ComboBox1.SelectedIndex).GetIPProperties.UnicastAddresses(i).Address
 
                BindSocket()
 
            End If
 
        Next
 
    End Sub
 
    Private Sub BindSocket()
 
        Try
            socket.Bind(New IPEndPoint(monip, 0))
 
            socket.SetSocketOption(SocketOptionLevel.IP, SocketOptionName.HeaderIncluded, True)
 
            Dim byin() As Byte = {1, 0, 0, 0}
 
            Dim byout() As Byte = {1, 0, 0, 0}
 
            socket.Blocking = False
 
 
            ReDim buffer(socket.ReceiveBufferSize)
 
            socket.IOControl(IOControlCode.ReceiveAll, byin, byout) 'what are OptionIn and OptionOut?
 
            'Pour que le socket commence à recevoir, il faut un buffer, une règle de comportement, une méthode de réception et savoir si on le fait à partir d'un socket déjà constitué
            socket.BeginReceive(buffer, 0, buffer.Length, SocketFlags.None, New AsyncCallback(AddressOf Reception), Nothing)
 
            ComboBox1.Enabled = False
 
        Catch ex As Exception
 
            ComboBox1.BackColor = Color.Red
 
        End Try
 
    End Sub
 
    'Méthode de réception
    Private Sub Reception(ar As IAsyncResult)
 
        'On cherche d'abord la taille du paquet
        If started = True Then
 
 
            Dim readlength As UInteger = BitConverter.ToUInt16(Byteswap(buffer, 2), 0)
 
            sourceport = BitConverter.ToUInt16(Byteswap(buffer, 22), 0) 'Yet, I want to take the one related to the data, not the others...
 
            destinationport = BitConverter.ToUInt16(Byteswap(buffer, 24), 0)
 
            'Ici on cherche à savoir quel protocole a été utilisé.
            If buffer(9) = 6 Then
 
                typez = "TCP"
 
            ElseIf buffer(9) = 11
 
                typez = "UDP"
 
            ElseIf buffer(9) = 1
 
                typez = "ICMP"
 
            Else
 
                typez = "???"
 
            End If
 
            'On cherche les IP de provenance et de destination
            ipfrom = New IPAddress(BitConverter.ToUInt16(buffer, 12))
 
            ipto = New IPAddress(BitConverter.ToUInt16(buffer, 16))
 
 
            'Si c'est un pacquet de/pour moi
            If (ipfrom.Equals(monip) = True Or (ipto.Equals(monip) = True)) And ipto.Equals(ipfrom) = False Then
 
                'Si on a pas mis le filtre
                If FilterIP = False Then
 
                    'On remplit stringz qui stocke le contenue du buffer
                    For i = 26 To readlength - 1
                        'If Char.IsLetterOrDigit(Chr(buffer(i))) = True Then
 
                        stringz = stringz & Chr(buffer(i))
 
                        'Else
 
                        'stringz = stringz & "."
 
                        'End If
 
                    Next
 
                    'On met des données dans DataGriedView, et dans la mesure ou c'est un thread différent, on l'invoque.
                    DataGridView1.Invoke(New MethodInvoker(AddressOf DGVMisAJour))
 
                End If
 
            End If
 
        End If
 
        socket.BeginReceive(buffer, 0, buffer.Length, SocketFlags.None, New AsyncCallback(AddressOf Reception), Nothing)
 
 
    End Sub
 
    Private Function Byteswap(buffer() As Byte, index As UInteger)
 
 
        Dim result(1) As Byte
 
        result(0) = buffer(index + 1)
 
        result(1) = buffer(index)
 
        Return result
 
    End Function
 
    'Mise à jour de la table
    Private Sub DGVMisAJour()
 
        'suppression de ligne s'il y en a trop/ NE DEVRAIT T'ON PAS LES STOCKER PLUTÔT?
        If DataGridView1.RowCount > 50 Then
 
            DataGridView1.Rows.RemoveAt(0)
 
        End If
 
 
 
        'On rajoute une ligne
        DataGridView1.Rows.Add()
 
        'On rajoute l'ip de provenance dans la première case
        DataGridView1.Rows(DataGridView1.Rows.Count - 1).Cells(0).Value = ipfrom.ToString & ":" & sourceport
 
        'On rajoute l'ip de destination dans la deuxième case
        DataGridView1.Rows(DataGridView1.Rows.Count - 1).Cells(1).Value = ipto.ToString & ":" & destinationport 'From 
 
        'On rajoute le protocole utilisé 
        DataGridView1.Rows(DataGridView1.Rows.Count - 1).Cells(2).Value = typez
 
        'On rajoute le contenu
        DataGridView1.Rows(DataGridView1.Rows.Count - 1).Cells(3).Value = stringz
 
        stringz = ""
 
    End Sub
 
 
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
 
        If started = True Then
 
            Button1.Text = "Start"
 
            started = False
 
        Else
 
            Button1.Text = "Stop"
 
            started = True
 
        End If
 
    End Sub
 
    Private Sub Form1_Resize(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Resize
 
        If formloaded = True Then
 
            DataGridView1.Size = Me.Size - sizediff
 
        End If
 
    End Sub
End Class

Here is its design:

View attachment 139135