New Threaded TCP Syn Port Scanner 2.0 released for Windows and Linux.

Version 2.0 - 22 September 2011

## 2.0 - Added option -s for Syn scan. 

- Scanning made faster thanks to Syn scan

- Added even more default ports

- Improved error handler for Syn scan

- Improved text output

- Fixed minor bugs: 

- changed pathname to oui.txt and port-numbers.txt files

- added missing call to cleanup function WSACleanup

A new branch of the program has been created to support Syn scan.

Syn scan was necessary because under some circumstances of heavy load, 

the Connect scan can hang routers. Syn scan is multithreaded and uses 

the standard library pcap on Unix/Linux operating systems. 

Please be aware that Syn scan requires a higher level of authorization,

if compared to connect sockets: in Unix/Linux pscan requires root 

privilege. 

In some operating systems, Syn scan is performed using connectionless 

"raw" sockets, therefore the usage of pscan is subject to possible 

restriction to the usage of raw sockets in such operating systems.

With Syn scan, option -w is not used because the program does not use

connected sockets, so it doesn't have to loop reading a socket until 

the timeout is reached. The receive function doesn't have to poll over 

a number of sockets, but simply reads the packets passing through the 

network card, for all ports, and displays the message of "open port"

when the packet coming from the remote IP contains the information that

the remote port is open. For the same reason, options -a and -n are not

used. The first one because packets sent to closed ports are simply 

not being replied to, so they cannot be counted; the second one because

the function that reads packets is one, and performs this by reading 

packets from the network card, not from multiple sockets.