https://coderwall.com/p/4j4azg/pair-program-anywhere-with-tmux-over-ssh-tunnel
https://github.com/roburio/pf-firewall/blob/master/TODO
ssh -R 2222:localhost:22 [email protected]
The local user would open a tmux session specifying a shared socket:
tmux -S /tmp/pair new-session -s pairing; chmod 0777 /tmp/pair