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Get two devices to communicate over WiFi without going through IP (p2p over the WiFi layers only)

I need to get two machines to communicate via WiFi without using IP (I do not want to use IP sockets). The solution preferably should work with both WiFi modes (infrastructure such as regular WiFi and ad-hoc such as WiFi Direct). A C# sample code would be great please.
I have searched a lot and could not find any code similar to a socket program that sends and receives data between two machines (p2p) but using only WiFi without any IP.

Apple's Multi-Peer Connectivity framework supports setting up a Peer to Peer connection without the developer having to manage the IP connectivity directly, but it uses IP to deliver data and is limited to Apple devices.
It's possible to do this if you are willing to write the low-level c code to do it, but any solution which avoids IP will have to recreate significant portions of the protocol to be useful and would almost certainly require much more work than just using the IP features of the OS.
For very simple forms of communication between Wi-Fi stations you can use custom Action Frames and Information Elements, but those require very low-level access to the driver.

Basic P2P chat application on the .NET framework

I am attempting to make a chat application on the .NET framework that will be able to communicate over the internet and not just LAN. I would like it to be P2P as to not require a central server. I don't mind which protocol it uses (UDP, TCP, etc) so long as I can send messages to almost any given IP.
All I would like to know is how to send data to another IP I know of, nothing else. I've searched around but the code is too complicated for me. (For example I've looked at the source code for torrent clients).
Help will be appreciated a lot thanks.
P.S.: I've heard about a method called UDP hole-punching if that sparks any plugs.

There is a small issue with your plan.
The server-centric approach does not serve only as a slow middle man, but also as a central point with known address to connect to, an anchor in the sea to attach to and clients connect to the static IP/name of the server.
Usually, users do not care what is their IP address on the internet...
So at the minimum, the server is good to get list of clients.
Nowadays you can use some services from Microsoft or Google or other.
Now rest of the P2P communication of clients between NAT comes with more learning: TCP_hole_punching
I would suggest reading all that stuff then look for some code or library that does it.
Here is older topic similar to yours looking for the hole punching library: tcp hole punching library

I have answered similar kind of things here Peer-to-Peer application using java, let me know if it helps or if you have any specific question about this. Basically you need NAT traversal, so you would find many different ways to achieve this based on your need. Even you can achieve this simply configuring your router by enabling UPnP.

NAT Traversal using only free STUN and TURN servers in C#

I am trying to make an online game application, which communicates with another pc peer-to-peer over the Internet.
Since both pc's are likely to be under NAT, and since I cannot afford an external server, I thought the only way is to use free STUN and TURN server, such as Numb.
However, after some research, I couldn't figure out how to use those servers to make a connection.
Is it really possible to use only those servers to do it? If it is, how would you do that?
Or is there an easier way of doing that?
I can use either UDP or TCP for this.

Take a look at the Internet Gateway Device Protocol. Is is an extension to the UPNP protocol, is very easy to use, is supported by pretty much every router out there and there are some free libs implementing this protocol.

STUN server for TCP flow

I am looking for a reliable STUN solution for the TCP flow. I have tried STUNT (by cornell University in the US) and XSTUNT (by a University in Taiwan). But they both seem old and useless.
What I want to do is to transfer files between two clients in two different networks via C#. Please let me know if you have any solution for either of the following:
And UDP-based Client/Server solutions for C#
Any TCP-based STUN server

Stuntman is a STUN server that supports TCP STUN.
www.stunprotocol.org
On that site, there's some links to some sample code, including C# implementations for client libraries. Most all are for UDP, but with a little work you can role your own C# code for TCP STUN by modifying one of the existing UDP code bases.
Afterwards, you will still need to implement a signaling service for exchanging address candidates (obtained directly or via STUN) and doing your own ICE-like connectivity checks.
For TCP, the easy solutions is to have both endpoints using two sockets. One socket or listening and another for connecting - but both share the same local port (ala SO_REUSEADDR socket option).
Another solution is to have each endpoint use just one socket. Both endpoints try repeatedly to do a TCP simultaneous connect. If the NAT's behave nicely, a connection can be made.
NAT traversal, especially TCP NAT Traversal, is not an exact science. There will always be cases where two endpoints can't get connected directly and will either have to fall back to UDP and/or go through a relay solution such as TURN.
Merge all the information above with the answer I wrote up last year on basic P2P/NAT traversal here.

Which local ip connects to a remote ip?

Im sorry if this been asked before, but couldnt find anything about this particular matter.
I try to find out with which of my own ip's my computer use to connect to a remote ip.
I use some kind of socket setup both ways etc, and im sending my ip (and other stuff with xml) to another server so it knows how to contact me.
But how do i figure out which ip i should send to it?
I have the servers ip or host name, but trying with
Dns.GetHostEntry("host").AddressList
But that only gives me the ip of the remote host and not how my computer reach it.
Is my question solveable at all or is this just wishful thinking?

Can you have the remote host capture that data? That end would surely have it.

If you're using UDP then this is exactly what the STUN protocol was designed for. STUN is used in VOIP applications (among other P2P systems) to be able to tell what a specific connection looks like on the internet.
One very reliable .NET implementation that implements STUN is included in the Lumisoft.NET library (source code available here). I've used it myself for to satisfy this specific task for applications ranging from VOIP to P2P VPN alternatives. It is very easy to use and is standards compliant.
NOTE: I am NOT in any way affiliated with Lumisoft, I've merely used their library in several different applications

Ok, quick update that wont help anyone except myself.
But.
Found out that i can send hostname instead of actual ip, will work for now and most cases, and let the DNS do what its suppose to do :)