[VB6] packet generation help needed

[-GP-]

hi all, I am curently making a server authentication program for authenticating a users IP address but i have no idea how to code the most vital part of the process ie. the programs ability to change the source IP of a packet from what it should be to form part of the validation key.

does anyone know any code or libery that i could use?
-GP-

[TheMinistered]

Here is a sample from one of my projects, we can derive a method of "ip validation" here in a minute from this:

Code Select Expand


Private Sub objTCPServer_ConnectionRequest(ByVal requestID As Long)

  Dim intReturn As Integer

    intReturn = AvailableSocket()
   
    If (intReturn > 0) Then
        If (objClientCollection.Add(objClient(intReturn), objUDPServer, objTCPServer.RemoteHostIP) Is Nothing = False) Then
            objClient(intReturn).Accept requestID
        End If
    Else
        If ((objClient.UBound - 1) < m_intSocketMaximum) Then
            intReturn = objClient.UBound + 1
           
            Load objClient(intReturn)
            If (objClientCollection.Add(objClient(intReturn), objUDPServer, objTCPServer.RemoteHostIP) Is Nothing = False) Then
                objClient(intReturn).Accept requestID
            End If
        End If
    End If
   
End Sub


allrighty then, here we go:

Code Select Expand


Private Sub objTCPServer_ConnectionRequest(ByVal requestID As Long)


    If( IPValidationFunction(objTCPServer.RemoteHostIP) = True) then
        'accept connection
    Else
        'reject connection
    End If
   
End Sub


IPValidationFunction would probably look up that ip in a database of some sort or a list and see if it's validated or not.

[-GP-]

Code Select Expand


Private Sub objTCPServer_ConnectionRequest(ByVal requestID As Long)


    If( IPValidationFunction(objTCPServer.RemoteHostIP) = True) then
        'accept connection
    Else
        'reject connection
    End If
   
End Sub


OMG how stupid do you think i am?!??!?!?
/slaps TheMinistered

right no iv got that out of my system...  just incase you missed my point ill spell it out:

I need help re-packaging or crafting custom packets to be sent to the server spesificly addressing changing of the ip address

lol now can the next posters asume im not a complete n00b please /begs
-GP-

[TehUser]

Because -GP- can apparently barely speak English, I'm going to make a guess.  I think what he wants to do is edit the packet on a raw level and mess with the IP header structure to change the source address.  But unless he learns how to write more proficiently, I doubt anyone will be able to help him.

[Ringo]

Because -GP- can apparently barely speak English, I'm going to make a guess.  I think what he wants to do is edit the packet on a raw level and mess with the IP header structure to change the source address.  But unless he learns how to write more proficiently, I doubt anyone will be able to help him.

Hehe, so im not the only one who can hardly read it then
Im unsure if hes making his own server, and making some kind of IP auth for it, or if hes trying to write a client for a server which has some kind of IP auth.
And if the server is TCP or UDP or somthing else.
sendto() in the winsock api might be helpfull (Please dont /slap me for taking a guess)

Code Select Expand


Private Type sockaddr_in
    sin_family       As Integer
    sin_port         As Integer
    sin_addr         As Long
    sin_zero(1 To 8) As Byte
End Type
Private Declare Function sendto Lib "ws2_32.dll" (ByVal s As Long, ByRef Buf As Any, ByVal buflen As Long, ByVal flags As Long, ByRef toaddr As sockaddr_in, ByVal tolen As Long) As Long


        Dim udpAddr As sockaddr_in
        With udpAddr
            .sin_addr = inet_addr(IP)
            .sin_port = htons(Port)
            .sin_family = 2 'AF_INET Internetwork
        End With
        If sendto(sckHdl, ByVal tmpData, Len(tmpData), 0&, udpAddr, Len(udpAddr)) = -1 Then
            MakeLog tmpData, vbRed, "SendToPacket() UDP_ERROR: Unable to Send Packet Via: " & sckHdl
        End If


[Joe[x86]]

lol now can the next posters asume im not a complete n00b please /begs

The way you spelled newbie, and the /beg at the end, makes me asume otherwise, but I'll do my best.

[rabbit]

Joe: stop being useless.

On-topic:  You may find using SOCK_RAW useful if you want to screw with TCP headers (which is what we are currently assuming).