What are the equivalent of these Linux IPTABLES lines for macOS High Sierra?

Multi tool use


What are the equivalent of these Linux IPTABLES lines for macOS High Sierra?
I am working for fun on a DOSBOX experiment to get Windows 3.11 WFG to connect to the internet through PPP and Trumpet Winsock. So far, with this script (https://github.com/knightmare2600/oldschool/blob/master/WFW/dosbox_ppp.sh) I got it to work on my RPi3 running Raspbian and DOSBOX 0.74, and I could hilariously view the google page (as well as low-bandwidth versions of some pages) on Internet Explorer 5.0! But for this script to work I had to add these lines after enabling ip forwarding:
Allow established connections
iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
iptables -A FORWARD -m state --state ESTABLISHED,RELATED -j ACCEPT
Masquerade
iptables -t nat -A POSTROUTING -o wlan0 -j MASQUERADE
Now, I want to do the same on my macbook air running macOS High Sierra. But I can't understand how to make the equivalent of these particular 3 lines for macOS. Anyone knows how or can direct me to the way? Thanks in advance.
By clicking "Post Your Answer", you acknowledge that you have read our updated terms of service, privacy policy and cookie policy, and that your continued use of the website is subject to these policies.