[REQUEST] Half-Sync Scan (SYN)

[Alfredsson418]

Is your feature request related to a problem? Please describe.
Be able to have more scanning methods.

Describe the solution you'd like
Using the Half-Sync scanning method where you do not send the ACK package back in a 3 way handshake, this is more "sneaky" than a regular TCP connection

Describe alternatives you've considered
NaN

Additional context
NaN

[Alfredsson418]

For this to work, I need to use raw sockets and the program needs to set up its own IP and TCP header, so I need the source address, so I need to change the network_interface.c file.

[Alfredsson418]

The only problem right now is that the checksum calculation for the TCP header is incorrect.

[Alfredsson418]

Problem as that the pseudoheader did not get the correct src IP address

When I changed how I handle the src interface (in a earlier comment) I forgot to add "_copy_addr()" in "verify_interface()", and because I specified a interface in the parameters, the program never got the src address

I also forgot to check for non IPv4 and IPv6 datatypes in ifaddrs

The SYN code/logic should be out on latest half-sync branch