--- /dev/null
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# L2TPv3 tunnel between 2 hosts
+#
+# host-1 | router | host-2
+# | |
+# lo l2tp | | l2tp lo
+# 172.16.101.1 172.16.1.1 | | 172.16.1.2 172.16.101.2
+# fc00:101::1 fc00:1::1 | | fc00:1::2 fc00:101::2
+# | |
+# eth0 | | eth0
+# 10.1.1.1 | | 10.1.2.1
+# 2001:db8:1::1 | | 2001:db8:2::1
+
+VERBOSE=0
+PAUSE_ON_FAIL=no
+
+which ping6 > /dev/null 2>&1 && ping6=$(which ping6) || ping6=$(which ping)
+
+################################################################################
+#
+log_test()
+{
+ local rc=$1
+ local expected=$2
+ local msg="$3"
+
+ if [ ${rc} -eq ${expected} ]; then
+ printf "TEST: %-60s [ OK ]\n" "${msg}"
+ nsuccess=$((nsuccess+1))
+ else
+ ret=1
+ nfail=$((nfail+1))
+ printf "TEST: %-60s [FAIL]\n" "${msg}"
+ if [ "${PAUSE_ON_FAIL}" = "yes" ]; then
+ echo
+ echo "hit enter to continue, 'q' to quit"
+ read a
+ [ "$a" = "q" ] && exit 1
+ fi
+ fi
+}
+
+run_cmd()
+{
+ local ns
+ local cmd
+ local out
+ local rc
+
+ ns="$1"
+ shift
+ cmd="$*"
+
+ if [ "$VERBOSE" = "1" ]; then
+ printf " COMMAND: $cmd\n"
+ fi
+
+ out=$(eval ip netns exec ${ns} ${cmd} 2>&1)
+ rc=$?
+ if [ "$VERBOSE" = "1" -a -n "$out" ]; then
+ echo " $out"
+ fi
+
+ [ "$VERBOSE" = "1" ] && echo
+
+ return $rc
+}
+
+################################################################################
+# create namespaces and interconnects
+
+create_ns()
+{
+ local ns=$1
+ local addr=$2
+ local addr6=$3
+
+ [ -z "${addr}" ] && addr="-"
+ [ -z "${addr6}" ] && addr6="-"
+
+ ip netns add ${ns}
+
+ ip -netns ${ns} link set lo up
+ if [ "${addr}" != "-" ]; then
+ ip -netns ${ns} addr add dev lo ${addr}
+ fi
+ if [ "${addr6}" != "-" ]; then
+ ip -netns ${ns} -6 addr add dev lo ${addr6}
+ fi
+
+ ip -netns ${ns} ro add unreachable default metric 8192
+ ip -netns ${ns} -6 ro add unreachable default metric 8192
+
+ ip netns exec ${ns} sysctl -qw net.ipv4.ip_forward=1
+ ip netns exec ${ns} sysctl -qw net.ipv6.conf.all.keep_addr_on_down=1
+ ip netns exec ${ns} sysctl -qw net.ipv6.conf.all.forwarding=1
+ ip netns exec ${ns} sysctl -qw net.ipv6.conf.default.forwarding=1
+ ip netns exec ${ns} sysctl -qw net.ipv6.conf.default.accept_dad=0
+}
+
+# create veth pair to connect namespaces and apply addresses.
+connect_ns()
+{
+ local ns1=$1
+ local ns1_dev=$2
+ local ns1_addr=$3
+ local ns1_addr6=$4
+ local ns2=$5
+ local ns2_dev=$6
+ local ns2_addr=$7
+ local ns2_addr6=$8
+
+ ip -netns ${ns1} li add ${ns1_dev} type veth peer name tmp
+ ip -netns ${ns1} li set ${ns1_dev} up
+ ip -netns ${ns1} li set tmp netns ${ns2} name ${ns2_dev}
+ ip -netns ${ns2} li set ${ns2_dev} up
+
+ if [ "${ns1_addr}" != "-" ]; then
+ ip -netns ${ns1} addr add dev ${ns1_dev} ${ns1_addr}
+ ip -netns ${ns2} addr add dev ${ns2_dev} ${ns2_addr}
+ fi
+
+ if [ "${ns1_addr6}" != "-" ]; then
+ ip -netns ${ns1} addr add dev ${ns1_dev} ${ns1_addr6}
+ ip -netns ${ns2} addr add dev ${ns2_dev} ${ns2_addr6}
+ fi
+}
+
+################################################################################
+# test setup
+
+cleanup()
+{
+ local ns
+
+ for ns in host-1 host-2 router
+ do
+ ip netns del ${ns} 2>/dev/null
+ done
+}
+
+setup_l2tp_ipv4()
+{
+ #
+ # configure l2tpv3 tunnel on host-1
+ #
+ ip -netns host-1 l2tp add tunnel tunnel_id 1041 peer_tunnel_id 1042 \
+ encap ip local 10.1.1.1 remote 10.1.2.1
+ ip -netns host-1 l2tp add session name l2tp4 tunnel_id 1041 \
+ session_id 1041 peer_session_id 1042
+ ip -netns host-1 link set dev l2tp4 up
+ ip -netns host-1 addr add dev l2tp4 172.16.1.1 peer 172.16.1.2
+
+ #
+ # configure l2tpv3 tunnel on host-2
+ #
+ ip -netns host-2 l2tp add tunnel tunnel_id 1042 peer_tunnel_id 1041 \
+ encap ip local 10.1.2.1 remote 10.1.1.1
+ ip -netns host-2 l2tp add session name l2tp4 tunnel_id 1042 \
+ session_id 1042 peer_session_id 1041
+ ip -netns host-2 link set dev l2tp4 up
+ ip -netns host-2 addr add dev l2tp4 172.16.1.2 peer 172.16.1.1
+
+ #
+ # add routes to loopback addresses
+ #
+ ip -netns host-1 ro add 172.16.101.2/32 via 172.16.1.2
+ ip -netns host-2 ro add 172.16.101.1/32 via 172.16.1.1
+}
+
+setup_l2tp_ipv6()
+{
+ #
+ # configure l2tpv3 tunnel on host-1
+ #
+ ip -netns host-1 l2tp add tunnel tunnel_id 1061 peer_tunnel_id 1062 \
+ encap ip local 2001:db8:1::1 remote 2001:db8:2::1
+ ip -netns host-1 l2tp add session name l2tp6 tunnel_id 1061 \
+ session_id 1061 peer_session_id 1062
+ ip -netns host-1 link set dev l2tp6 up
+ ip -netns host-1 addr add dev l2tp6 fc00:1::1 peer fc00:1::2
+
+ #
+ # configure l2tpv3 tunnel on host-2
+ #
+ ip -netns host-2 l2tp add tunnel tunnel_id 1062 peer_tunnel_id 1061 \
+ encap ip local 2001:db8:2::1 remote 2001:db8:1::1
+ ip -netns host-2 l2tp add session name l2tp6 tunnel_id 1062 \
+ session_id 1062 peer_session_id 1061
+ ip -netns host-2 link set dev l2tp6 up
+ ip -netns host-2 addr add dev l2tp6 fc00:1::2 peer fc00:1::1
+
+ #
+ # add routes to loopback addresses
+ #
+ ip -netns host-1 -6 ro add fc00:101::2/128 via fc00:1::2
+ ip -netns host-2 -6 ro add fc00:101::1/128 via fc00:1::1
+}
+
+setup()
+{
+ # start clean
+ cleanup
+
+ set -e
+ create_ns host-1 172.16.101.1/32 fc00:101::1/128
+ create_ns host-2 172.16.101.2/32 fc00:101::2/128
+ create_ns router
+
+ connect_ns host-1 eth0 10.1.1.1/24 2001:db8:1::1/64 \
+ router eth1 10.1.1.2/24 2001:db8:1::2/64
+
+ connect_ns host-2 eth0 10.1.2.1/24 2001:db8:2::1/64 \
+ router eth2 10.1.2.2/24 2001:db8:2::2/64
+
+ ip -netns host-1 ro add 10.1.2.0/24 via 10.1.1.2
+ ip -netns host-1 -6 ro add 2001:db8:2::/64 via 2001:db8:1::2
+
+ ip -netns host-2 ro add 10.1.1.0/24 via 10.1.2.2
+ ip -netns host-2 -6 ro add 2001:db8:1::/64 via 2001:db8:2::2
+
+ setup_l2tp_ipv4
+ setup_l2tp_ipv6
+ set +e
+}
+
+setup_ipsec()
+{
+ #
+ # IPv4
+ #
+ run_cmd host-1 ip xfrm policy add \
+ src 10.1.1.1 dst 10.1.2.1 dir out \
+ tmpl proto esp mode transport
+
+ run_cmd host-1 ip xfrm policy add \
+ src 10.1.2.1 dst 10.1.1.1 dir in \
+ tmpl proto esp mode transport
+
+ run_cmd host-2 ip xfrm policy add \
+ src 10.1.1.1 dst 10.1.2.1 dir in \
+ tmpl proto esp mode transport
+
+ run_cmd host-2 ip xfrm policy add \
+ src 10.1.2.1 dst 10.1.1.1 dir out \
+ tmpl proto esp mode transport
+
+ ip -netns host-1 xfrm state add \
+ src 10.1.1.1 dst 10.1.2.1 \
+ spi 0x1000 proto esp aead 'rfc4106(gcm(aes))' \
+ 0x0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f 128 mode transport
+
+ ip -netns host-1 xfrm state add \
+ src 10.1.2.1 dst 10.1.1.1 \
+ spi 0x1001 proto esp aead 'rfc4106(gcm(aes))' \
+ 0x0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f 128 mode transport
+
+ ip -netns host-2 xfrm state add \
+ src 10.1.1.1 dst 10.1.2.1 \
+ spi 0x1000 proto esp aead 'rfc4106(gcm(aes))' \
+ 0x0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f 128 mode transport
+
+ ip -netns host-2 xfrm state add \
+ src 10.1.2.1 dst 10.1.1.1 \
+ spi 0x1001 proto esp aead 'rfc4106(gcm(aes))' \
+ 0x0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f 128 mode transport
+
+ #
+ # IPV6
+ #
+ run_cmd host-1 ip -6 xfrm policy add \
+ src 2001:db8:1::1 dst 2001:db8:2::1 dir out \
+ tmpl proto esp mode transport
+
+ run_cmd host-1 ip -6 xfrm policy add \
+ src 2001:db8:2::1 dst 2001:db8:1::1 dir in \
+ tmpl proto esp mode transport
+
+ run_cmd host-2 ip -6 xfrm policy add \
+ src 2001:db8:1::1 dst 2001:db8:2::1 dir in \
+ tmpl proto esp mode transport
+
+ run_cmd host-2 ip -6 xfrm policy add \
+ src 2001:db8:2::1 dst 2001:db8:1::1 dir out \
+ tmpl proto esp mode transport
+
+ ip -netns host-1 -6 xfrm state add \
+ src 2001:db8:1::1 dst 2001:db8:2::1 \
+ spi 0x1000 proto esp aead 'rfc4106(gcm(aes))' \
+ 0x0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f 128 mode transport
+
+ ip -netns host-1 -6 xfrm state add \
+ src 2001:db8:2::1 dst 2001:db8:1::1 \
+ spi 0x1001 proto esp aead 'rfc4106(gcm(aes))' \
+ 0x0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f 128 mode transport
+
+ ip -netns host-2 -6 xfrm state add \
+ src 2001:db8:1::1 dst 2001:db8:2::1 \
+ spi 0x1000 proto esp aead 'rfc4106(gcm(aes))' \
+ 0x0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f 128 mode transport
+
+ ip -netns host-2 -6 xfrm state add \
+ src 2001:db8:2::1 dst 2001:db8:1::1 \
+ spi 0x1001 proto esp aead 'rfc4106(gcm(aes))' \
+ 0x0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f 128 mode transport
+}
+
+teardown_ipsec()
+{
+ run_cmd host-1 ip xfrm state flush
+ run_cmd host-1 ip xfrm policy flush
+ run_cmd host-2 ip xfrm state flush
+ run_cmd host-2 ip xfrm policy flush
+}
+
+################################################################################
+# generate traffic through tunnel for various cases
+
+run_ping()
+{
+ local desc="$1"
+
+ run_cmd host-1 ping -c1 -w1 172.16.1.2
+ log_test $? 0 "IPv4 basic L2TP tunnel ${desc}"
+
+ run_cmd host-1 ping -c1 -w1 -I 172.16.101.1 172.16.101.2
+ log_test $? 0 "IPv4 route through L2TP tunnel ${desc}"
+
+ run_cmd host-1 ${ping6} -c1 -w1 fc00:1::2
+ log_test $? 0 "IPv6 basic L2TP tunnel ${desc}"
+
+ run_cmd host-1 ${ping6} -c1 -w1 -I fc00:101::1 fc00:101::2
+ log_test $? 0 "IPv6 route through L2TP tunnel ${desc}"
+}
+
+run_tests()
+{
+ local desc
+
+ setup
+ run_ping
+
+ setup_ipsec
+ run_ping "- with IPsec"
+ run_cmd host-1 ping -c1 -w1 172.16.1.2
+ log_test $? 0 "IPv4 basic L2TP tunnel ${desc}"
+
+ run_cmd host-1 ping -c1 -w1 -I 172.16.101.1 172.16.101.2
+ log_test $? 0 "IPv4 route through L2TP tunnel ${desc}"
+
+ run_cmd host-1 ${ping6} -c1 -w1 fc00:1::2
+ log_test $? 0 "IPv6 basic L2TP tunnel - with IPsec"
+
+ run_cmd host-1 ${ping6} -c1 -w1 -I fc00:101::1 fc00:101::2
+ log_test $? 0 "IPv6 route through L2TP tunnel - with IPsec"
+
+ teardown_ipsec
+ run_ping "- after IPsec teardown"
+}
+
+################################################################################
+# main
+
+declare -i nfail=0
+declare -i nsuccess=0
+
+while getopts :pv o
+do
+ case $o in
+ p) PAUSE_ON_FAIL=yes;;
+ v) VERBOSE=$(($VERBOSE + 1));;
+ *) exit 1;;
+ esac
+done
+
+run_tests
+cleanup
+
+printf "\nTests passed: %3d\n" ${nsuccess}
+printf "Tests failed: %3d\n" ${nfail}