File tayga_setup_tun of Package tayga

#!/bin/bash
CFG="/etc/tayga.conf"
IP4_SET="$(   sed -n 's|[[:blank:]]*dynamic-pool[[:blank:]]\+\([0-9./]\+\)[[:blank:]]*|\1|p'    ${CFG} | sed 's|#.*||')"
IP6_SET="$(   sed -n 's|[[:blank:]]*prefix[[:blank:]]\+\([0-9a-fA-F:/]\+\)[[:blank:]]*|\1|p'    ${CFG} | sed 's|#.*||')"
IP4="$(       sed -n 's|[[:blank:]]*ipv4-addr[[:blank:]]\+\([0-9.]\+\)[[:blank:]]*|\1|p'        ${CFG} | sed 's|#.*||')"
IP6="$(       sed -n 's|[[:blank:]]*ipv6-addr[[:blank:]]\+\([0-9:a-fA-F]\+\)[[:blank:]]*|\1|p'  ${CFG} | sed 's|#.*||')"
IF="$(        sed -n 's|[[:blank:]]*tun-device[[:blank:]]\+\([0-9a-zA-Z/]\+\)[[:blank:]]*|\1|p' ${CFG} | sed 's|#.*||')"

tayga --mktun --config ${CFG}
ip link set ${IF} up
ip addr add ${IP4} dev ${IF}                       # local endpoint of the tunnel
[ -z "${IP6}" ] || ip addr add ${IP6} dev ${IF}    # local IPv6
ip route add ${IP4_SET} dev ${IF}                  # our IPv4
ip route add ${IP6_SET} dev ${IF}                  # our IPv6

# Setup NAT
if type iptables ip6tables &>/dev/null
then
	OUT="$(ip r | sed -n 's|default.*dev[[:blank:]]\([0-9a-zA-Z/]\+\)|\1|p')"
	iptables -t nat -I POSTROUTING -s ${IP4_SET} -o ${OUT} -j MASQUERADE
	iptables -I FORWARD -i ${OUT} -o ${IF} -m state --state RELATED,ESTABLISHED -j ACCEPT
	iptables -I FORWARD -i ${IF} -o ${OUT} -j ACCEPT
	ip6tables -I FORWARD -s ${IP6_SET} -j ACCEPT
	ip6tables -I INPUT -s ${IP6_SET} -j ACCEPT
else
	echo 'Unable to locate iptables, Tayga will not operate unless you install the necessary rules in your firewall.'
fi