AutoIt andRecv (packets)

[RyuHayabusa]

Greetings,

I am new to AutoIt and I never coded with anything network related. Here is what I would like to do: when I receive a specific network packet from a specific IP I would like to execute a specific routine.

That routine is already coded, I only need the network part and I have no clue how to create it.

I was able to get the packet I need to check with WPE Pro:

Can anyone help me out please?

Thanks a lot in advance for your help and support.

[martin]

Welcome to the AUtoIt forums RyuHayabusa

Have you looked at the TCP* functions in the help?

[RyuHayabusa]

Greetings,

I tried to open the help in AutoIt previously or looking at previous topics but I was not able to find what I needed. Also when I am in SciTE, if I go to the help menu nothing happens.

Do you refer to another help menu maybe?

Thanks.

[darkjohn20]

Martin, he wants to get packets from another program. Doesn't the TCP commands only allow communication between other AutoIt scripts?

[monoceres]

Martin, he wants to get packets from another program. Doesn't the TCP commands only allow communication between other AutoIt scripts?

No. The TCP functions uses the sends the same data as any other client using the TCP protocol. Data is always just data regardless of language or platform.

[darkjohn20]

Oh. So how would you connect to something other than another script that was using TCP? Would you just have to find the right port and listen?

Edited December 31, 2009 by darkjohn20

[monoceres]

Yeah, of course you would have to figure out how the data is formatted by the other application, but that's always an issue when dealing with other application.

To test, try running this script:

TCPStartup()
$listen = TCPListen(@IPAddress1,12345)
ConsoleWrite(@IPAddress1&@CRLF)

While True
    $socket = TCPAccept($listen)

    While True
        $data = TCPRecv($socket,4096)
        If @error Then ExitLoop
        ConsoleWrite($data)
        Sleep(1)
    WEnd
    Sleep(1)
WEnd

Then start cmd and type "telnet YOURIP 12345" (install telnet from control panel if you're on vista+) and start typing things after the connection is enabled.

[darkjohn20]

Yeah, I understand it all. Thanks.

(Can't be bothered to install Telnet at the moment. I'll just use other programs. I've done it with telnet when I had Vista though. )

[RyuHayabusa]

Greetings,

Thanks a lot for your help, I was able to trap what packets are coming but how can I see if a specific one (like in my first post) is being received. For instance, from the packet in my first post, what is the information that I should "check" on the listen?

Thanks.

[darkjohn20]

While 1
    $Recv = TcpRecv($Listen, $Size)

    If $Recv <> "" Then
    ;You got a packet
    Endif
    
Wend

Is that what you mean?

Edited December 31, 2009 by darkjohn20

[RyuHayabusa]

Greetings,

What I mean is what information on the following packet would I need to check with the "If" clause:

Edited December 31, 2009 by RyuHayabusa

[martin]

Greetings,

What I mean is what information on the following packet would I need to check with the "If" clause:

Do you mean how do you check that you have received that particular packet?

If so then you have to make sure that you receive it as binary because if you receive it as a string you will loose the second two strings. The data in that packet is either binary or it is 3 strings because 0x00 is used to mark the end of a string. So if you receive is as a string then you will only see the first one.

$stringToFind1 = "GDF|298;3;0"
$StringToFind2 = "Im0144"
$StringToFind3 = "JX|36;5268960;71741;72385" 

; ignore the strings and look for binary data
$binaryToFind = Binary('0x4744467C3239383B333B3000496D30313434004A587C33363B353236383936303B37313734313B373233383500')

;or, don't ignore the strings but convert them to binary
$binaryToFind = Binary(StringToBinary($stringToFind1) & "00" & STringReplace(StringToBinary($stringToFind2),"0x","") & "00" & StringReplace(StringToBinary($stringToFind3),"0x","") & "00" )

While 1
 $Recv = TcpRecv($Listen, $Size,1)

 If $Recv = $binaryToFind then
 ;You got the packet
 exitloop; or dosomething()
 Endif
 
Wend

To extract strings from binary data can be a bit messy, because if you use BinaryToString for binary data which contains more than one string you will get a string which is the length of all the strings but you will only see the first one.

So you could do this

;say $Recv is the received binary data

$s1 = BinaryToString($Recv)
Dim $ss[5]
$index = 0

for $n = 1 to stringlen($s1)
    ;ConsoleWrite(hex(asc(stringmid($s1,$n,1)),2) & @CRLF)
    if stringmid($s1,$n,1)='' Then
        $index += 1
        if $index > ubound($ss) then Redim $ss[$index+4]
    Else
    $ss[$index] &= stringmid($s1,$n,1)
    EndIf

Next

for $n = 0 to $index;show the extracted strings
    ConsoleWrite($ss[$n] & @CRLF)
Next

EDIT: I might be wrong about receiving the dat as a string. It could be that the string woulb be exactly the same as converting the binary data to a string, but you would still need to extract the strings as I showed, or some better way.

If I haven't confused you with this post then I must try harder

Edited January 1, 2010 by martin

[RyuHayabusa]

Greetings,

Thanks a lot for your help! I will go on from there, to be honest I was busy on the holidays but this is answering my question just fine. I will need to test it and I should be able to debug/modify if needed.

Thanks a lot again to all!