View source for Minix2 16bit ppp demo

DOSBox supports nullmodem connection using tcp sockets. In this page, we describe a simple networking slip configuration on linux (ubuntu) host, but for Minix 2.0.2 guest operating system. With socat or similar tools on host's side, you can connect these sockets with slattach, and the DOSBox guest can access internet as well.

== WARNING! ==

The included script and manual is dangerous. It needs sudo or root access to the target host, uses external dependencies, can cause damage and irrecoverable package dependency problems via apt installing, and may be harmful when you are not familiar with tcp/ip ipv4 networking or linux iptables/slattach/etc. tools.

== Prerequisities under ubuntu ==

=== Internet settings ===

A working internet connection is essential.
10.1.1.0/24 network must be unused! Otherwise network range collision will happen, causing unpredictable results!

=== Required ubuntu packages ===

The followings need to be installed:
 apt-get install bash dosbox iptables socat sudo

=== The main script: minixbox.sh ===

The content of minixbox.sh:
 #! /bin/bash
 flushipt() {
   for i in $( iptables -t nat -n --line-numbers -L \
     | awk '/^Chain POSTROUTING/,/^$/{if(/^[0-9].*[^0-9]10\.1\.1\./)print $1}' | tac )
   do
     iptables -t nat -D POSTROUTING "$i"
   done
   for i in $( iptables -t nat -n --line-numbers -L \
     | awk '/^Chain PREROUTING/,/^$/{if(/^[0-9].*[^0-9]10\.1\.1\./)print $1}' | tac )
   do
     iptables -t nat -D PREROUTING "$i"
   done
 if id -u | grep -q '^0'; then
   :
 else
   echo 'dosbox slip deployment for minix2 guest'
   echo 'Author(s): Naszvadi Peter et al'
   echo
   echo "Please run ''$0'' as root!"
   echo
   exit 1
 fi
 set -e
 echo Checking necessary applications:
 which dosbox
 which iptables
 which slattach
 which socat
 which sudo
 which tac
 set +e
 flushipt
 Dev_Pts="$(mktemp -u /tmp/slipXXX)"
 socat PTY,link="$Dev_Pts",raw,echo=0 TCP-LISTEN:8040 &
 Pid_Saved_3="$!"
 sleep 1
 Uid="$(find "$0" -printf '%U' -quit)"
 sudo -u "#$Uid" dosbox -conf mnxslip.cnf &
 Pid_Saved="$!"
 grep -q 1 /proc/sys/net/ipv4/ip_forward || ( echo 1 1>/proc/sys/net/ipv4/ip_forward )
 slattach -d -s 9600 -p adaptive "$Dev_Pts" 1>/dev/null 2>/dev/null &
 Pid_Saved_2="$!"
 sleep 3
 ifconfig sl0 10.1.1.3 dstaddr 10.1.1.1 netmask 255.255.255.0 mtu 576 up 1>/dev/null 2>/dev/null
 set -x
 iptables -t nat -A POSTROUTING -s 10.1.1.0/24 -j MASQUERADE 1>/dev/null 2>/dev/null
 set +x
 while ps "$Pid_Saved" 1>/dev/null 2>/dev/null; do sleep 5
 done 1>/dev/null 2>/dev/null
 2>&-
 kill -9 "$Pid_Saved_2" "$Pid_Saved_3" 1>/dev/null 2>/dev/null
 flushipt
 exit 0

=== The custom configuration file: mnxslip.cnf ===

The content of mnxslip.cnf:
 [serial]
 serial1=nullmodem server:localhost port:8040 transparent:1
 [autoexec]
 mount C .
 C:
 C:BOOT.COM PPP16

== Launch a networked session under ubuntu ==

=== Creating working directory ===

Create a standalone folder, e.g. mkdir ~/minixslip

=== Creating files ===

Necessary files:
* dosppp1615.zip
* minixbox.sh
* mnxslip.cnf
The latters should be saved from this site.

Set attributes of minixbox.sh:
 chmod 755 minixbox.sh
Download and extract dosppp1615.zip: link and checksums at the bottom of this page

Till this, the above were the once time steps.

=== Launch ./minixbox.sh ===

Do it with sudo:
 sudo ./minixbox.sh
If everything is okay, you can get similar results like these - setup slip in minix2 prompt after logging in with passwordless root account:
 slip.drv -b 38400 -c -i 10.1.1.1 /dev/tty00 & echo nameserver 8.8.8.8 >/etc/resolv.conf
Press enters after entering command till getting command prompt back.

[[File:dosbox_minix2_slipsetup.gif]]

== Applications ==

=== Telnet ===

[[File:dosbox_minix2_telnetbbs.gif]]

=== IRC client ===

[[File:dosbox_minix2_minirc.gif]]

== Minix-specific ==

Graceful shutdown of guest in guest CLI:
 # sync
 # shutdown
Then type exit + ENTER at the appearing prompts!

=== Links ===

* http://minix1.woodhull.com/pub/demos-2.0/ppp16/dosppp1615.zip
** cksum: 3791977839 1495039
** md5sum: 1e6d6f3d6ecbf4a2c0593d95ea393618
** sha256sum: 739f34d9ae4ce28097a840cc075cc6a336a7ad44b91d8d300b15d19f73eb5ff2