RAW Sockets
lazarus / 38-Networking and Web Programming

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el3ctrolyte · 2020-08-25 23:38

I want to use synapse to make a simple sniffer program but can't seem
to get the basic thing working. I am using the TRAWBlockSocket class
but can seem to get it it work. Here is my code sample:

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i program
project1;uses    blcksock,sysutils;var  sock:TRAWBlockSocket; 
mem:array[0..1023] of byte;begin  sock:=TRAWBlockSocket.Create; 
sock.Listen; //don't know if this is what i should do, i have tried it
without this line and still doesn't work  while true do  begin   
sock.RecvBuffer(@mem,1024);    if mem[0] <> $00 then    begin     
writeln(IntToHex(mem[0],2));    end;  end;end. 
I can't find any example's on the internet about how to use
TRAWBlockSocket to sniff packets. Also i am on windows.

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Thaddy · 2020-08-26 07:01

For Windows to work with raw sockets, you need WinPcap to be
installed. https://www.winpcap.org/
I wrote a sniffer back in 2004 for the KOL library that also works
with FPC (needs KOL library)
http://members.chello.nl/t.koning8/kolsniffer.zip
Maybe you can steal some of my code (with permission). It at least
shows you the requirements.
There is no standard support for raw sockets on Windows at the user
level. Hence you need a driver like WinPcap.
My code is also available from the WinPcap site, but they refer to an
old version of KOL.

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el3ctrolyte · 2020-08-26 22:51

Thanks for your reply! I tried the same code in linux and still
doesn't work, not even with root privileges. I wish there was some
kind of example of how to use TRawBlocksocket for making a sniffer. I
would prefer it if i didn't need to leave synapse. I primarily work in
linux but just wrote this little piece of code on a windows machine.