[Simh] Tun/Tap in Mint for RSX-11M Plus 4.6 running in SimH PDP11

[Mark Pizzolato]

On Sunday, June 23, 2019 at 6:07 PM, Will Senn wrote:
> This question may best be asked elsewhere but I'm struggling to make it work
> with SimH, so here it is :)
> 
> tldr; How can I get tun/tap working with Mint 19 and SimH RSX-11M Plus
> 4.6 so that I can access the internet from the instance and telnet to it from
> another machine on the network?

Use NAT networking to do this.

> Here's the background... I am trying to get RSX-11M Plus 4.6 working in SimH
> with networking on my Mint 19.1 T430 Thinkpad and it's proving difficult (both
> in execution and understanding). I've tried this tap stuff before and remember
> being uber frustrated then, too. But now, I know way more about stuff then I
> did back then.
> 
> System: T430 ThinkPad w/16GB Ram, SSD's, 1600x screen.
> 
> OS: Linux Mint 19.1 (debian/ubuntu derivative).
> 
> Software: SimH built with: make USE_READER_THREAD=1
> USE_TAP_NETWORK=1
> USE_INT64=1 vax vax780 pdp11 pdp8

You should not need to pass any extra make arguments to use any particular form of networking.

    $ make vax vax780 pdp11 pdp8 

This will do the right thing to build network capable simulators that can use either tap or NAT networking.

> What I'm trying to do: Get my RSX-11M talking to the internet and be able to
> telnet into it, preferably from another laptop on the network.
> 
> What I've tried: followed a gist by Upi Temminen for getting it running on a pi:
> 
> https://gist.github.com/desaster/c49b0f7afa5e061b8f33f159e521b6ee
> 
> After installing parprouted, uml-utilities, tunctl, and simh as described, did the
> following:
> 
> /etc/sysctl.conf
> net.ipv4.conf.all.proxy_arp=1
> net.ipv4.ip_forward=1
> 
> sudo vi /etc/network/interfaces.d/tap
> auto tap-simh0
> iface tap-simh0 inet manual
>      pre-up tunctl -t tap-simh0 -u simhuser
>      up ip link set tap-simh0 up
>      up /usr/sbin/parprouted wlp3s0 tap-simh0
>      up /sbin/ip link set wlp3s0 promisc on
>      post-down ip link set tap-simh0 down
>      post-down tunctl -d tap-simh0
> 
> auto tap-simh1
> iface tap-simh1 inet manual
>      pre-up tunctl -t tap-simh1 -u simhuser
>      up ip link set tap-simh1 up
>      up /usr/sbin/parprouted wlp3s0 tap-simh1
>      up /sbin/ip link set wlp3s0 promisc on
>      post-down ip link set tap-simh1 down
>      post-down tunctl -d tap-simh1

I'm not completely familiar with the Pi network devices, but if wlp3s0 is a WiFi interface, you will be extremely challenged and frustrated and likely never get this to work.

USE NAT!!!!

- Mark