Linux

Wait, why are you doing this? Is there some network throughput requirement? Just bridging wifi to Ethernet won't get you Ethernet speed, latency, or stability (since the back haul to the internet is WiFi).

This feels a bit like an XY Problem.

Edit: Wait, I'm guessing the company doesn't allow wifi? (That seems weird, if they're using a mandatory VPN, it shouldn't matter how the laptop gets to the internet). Leaving this in case anyone doesn't know about XY Problems. They've bitten me several times over the years.

Assuming that:

• your Linux Laptop uses wlan0 for its wireless connection and your home network uses 192.168.1.x for IP space.

On the Linux laptop:

• as root or with sudo -- enable IP forwarding and load the change with sysctl -p.

sudo sysctl net.ipv4.ip_forward
sudo sysctl -p

• if you have ufw installed and running -- setup a NAT masquerading rule for any hosts forwarding IPv4 traffic to it.
  add this line to /etc/ufw/before.rules file right after the "*nat" line

:POSTROUTING ACCEPT [0:0]

-A POSTROUTING -s 192.168.1.1/24 -o wlan0 -j MASQUERADE

On the mac:

• set your IP address manually to be on the same LAN as the Linux laptop, but for the gateway address... point that at the IP for the Linux Laptop.

Yes, it's called IP Forwarding. I don't have iptables lines ready, it's been a long while since I've done it

Get a cheap travel router that can use "bridge mode" to receive the wifi and pass along the connection through it's ethernet port to your computer.

If you have a mobile phone you just just connect it to your laptop via USB and turn on tethering to use your mobile data.

Don't do it the hard way. Get a GL.iNet GL-SFT1200 (or any but that one is inexpensive) and set it up as an extender for the neighbor WiFi. It's a basic function of the router and the Mac shouldn't know the difference.

You can, but you need to basically completely turn that laptop into a router. A cheap WiFi bridge would be more flexible.

Basically what you want is to turn the linux laptop into a router. Thats doable. I believe Ars did an article on a similar build a couple years ago.

And here it is: https://arstechnica.com/gadgets/2016/04/the-ars-guide-to-building-a-linux-router-from-scratch/

It's an old build based on an almost 10 year old version of Ubuntu, but quickly glancing through it, I didn't see anything completely out of date. Version numbers will have changed and perhaps some package names will have changed but it will give you a starting point for further research. You won't want to cargo cult this build.

I think the main difference is that your internet would be coming in from the wifi interface and going out the ethernet interface rather than the other way around.

https://askubuntu.com/a/1547100/16134 should work.

@sorrybookbroke sure, you just need $99.99 apple-compatible cross-over ethernet cable