From: mrpink <adnarim@...>
Date: 2007-04-16T22:30:08+09:00
Subject: simple but fast port scanner

hi,
I wanna write a simple and fast port scanner which scans one host for 
some open ports. I need to do this in a SYN scan mode which is described 
as follows:

'This technique is often referred to as half-open scanning, because you 
don't open a full TCP connection. You send a SYN packet, as if you are 
going to open a real connection and then wait for a response. A SYN/ACK 
indicates the port is listening (open), while a RST (reset) is 
indicative of a non-listener. If no response is received after several 
retransmissions, the port is marked as filtered. The port is also marked 
filtered if an ICMP unreachable error (type 3, code 1,2, 3, 9, 10, or 
13) is received.'

But a simple question ;) How do I send a SYN packet ? Google didn't want 
to drop a usefull answer for that question so I hope I can get here some 
infos about that.

greets