Add Local Network Multiplayer to a Singleplayer C++ Game

I have a game developed in C++ (it's an Arkanoid clone), and I have to add multiplayer to the game. It must be done in plain C++ using sockets, may use a lib/framework, like RakNet or WinSock. It's nothing big and should be easy for anyone with Sockets knowledge in C++. Requirements: - When start the game, ask if single player or multiplayer, if singleplayer is selected, play as it is now; - If multiplayer is selected, ask if you want to join or host a game; - If join is selected, ask for the host IP then connect, if host is selected, show your local IP, and wait for the connection. - Then play the game as it is now, but with 2 "bases", one controlled by the local player, one controlled by the other player, from another computer. - Final result should be something close to the attached imaged, where each player control one of the white bases at the bottom. Sumarizing it, the game now is single player only, you need to make it possible to play multiplayer in a local network. Multiplayer is same as single player, but with 2 "bases", one controlled by each player