setup for vtun

readme.txt

all of this vtun stuff can actually be done with socat apparently...

http://www.dest-unreach.org/socat/doc/socat-tun.html

or similarly if you have secure TCP port forwarding on 5000 then you can do:

socat TUN:10.10.0.2/24,iff-up TCP4-LISTEN:5000,bind=127.0.0.1,fork # server
socat TUN:10.10.0.1/24,iff-up TCP4:127.0.0.1:5000 # client

iptables -A FORWARD -i tun0 -o eth0 -m state --state RELATED,ESTABLISHED -j ACCEPT
iptables -A FORWARD -i eth0 -o tun0 -j ACCEPT
iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE

MAGIC


docker run -d --privileged --name vtun-client ubuntu:18.04 sleep infinity

docker run -d --privileged --name vtun-server ubuntu:18.04 sleep infinity

docker exec -it vtun-server bash -c 'apt update -y && apt install -y net-tools iproute2 screen vim dnsutils netcat python3 vtun curl inetutils-ping iptables'


or if setting up a pod use:

setting up the pod/container requires:

    volumeMounts:
    - name: tundevice
      mountPath: /dev/net/tun
  volumes:
  - name: tundevice
    hostPath:
      path: /dev/net/tun
      type: CharDevice


docker exec -it vtun-server vtund -s -n

docker exec -it vtun-client vtund -n cobra 172.17.0.2


# on the server
ip link add dummy0 type dummy
ip addr add 10.0.2.1/24 broadcast 10.0.2.255 dev dummy0
ip link set dummy0 up
ip route add 10.0.3.0/24 via 10.0.0.3 dev tun0

# on the client
ip link add dummy0 type dummy
ip addr add 10.0.3.1/24 broadcast 10.0.3.255 dev dummy0
ip link set dummy0 up
ip route add 10.0.2.0/24 via 10.0.0.2 dev tun0

# on the client
ip route replace default via 10.0.0.2 dev tun0
# also seems to work via 10.0.0.3

# on the server
iptables -A FORWARD -i tun0 -o eth0 -m state --state RELATED,ESTABLISHED -j ACCEPT
iptables -A FORWARD -i eth0 -o tun0 -j ACCEPT
iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE

# reset
iptables --flush
iptables -t nat --flush


# this does not work because is at level of MAC not IP
ip link add name br0 type bridge
ip link set dev br0 up
ip link set dev tun0 master br0
ip link set dev dummy0 master br0

ip link del br0

client-vtund.conf

options {
  port 5000;		# Connect to this port.
  timeout 60;		# General timeout

  # Path to various programs
  ppp		/usr/sbin/pppd;            
  ifconfig	/sbin/ifconfig;
  route		/sbin/route;
  firewall	/sbin/ipchains;
  ip		/sbin/ip;
}

# same as above, but with iproute2 command
cobra {
  passwd  secret123;	# Password
  device tun0; 		# Device tun0 
  persist yes;		# Persist mode 
  up {
	# Connection is Up 

	# Assign IP addresses. 
	ip "link set %% up multicast off mtu 1450";
	ip "-family inet addr add 10.0.0.3 peer 10.0.0.2 dev %%";
  };
}

server-vtund.conf

options {
  port 5000;		# Listen on this port.
  bindaddr { iface lo; };

  # Syslog facility
  syslog 	daemon;

  # Path to various programs
  ppp 		/usr/sbin/pppd;            
  ifconfig 	/sbin/ifconfig;
  route 	/sbin/route;
  firewall 	/sbin/ipchains;
  ip		/sbin/ip;
}

# Default session options 
default {
  compress no;  	# Compression is off by default
  speed 0;		# By default maximum speed, NO shaping
}

# the same as above, but with iproute2 command
cobra {
  passwd  secret123;	# Password
  type  tun;		# IP tunnel 
  proto tcp;   		# TCP protocol
  compress  lzo:9;	# LZO compression level 9
  encrypt  yes;		# Encryption
  keepalive yes;	# Keep connection alive

  up {
	# Connection is Up 

	# 10.0.0.2 - local, 10.0.0.3 - remote
	ip "link set %% up multicast off mtu 1450";
	ip "-family inet addr add 10.0.0.2 peer 10.0.0.3 dev %%";
  };
}

on Ubuntu 22.04 this issue comes up: https://www.mail-archive.com/[email protected]/msg1956907.html