Re: [net-next v4 3/4] selftests: seg6: add selftest for SRv6 H.Encaps.Red behavior

[Paolo Abeni]

On Fri, 2022-07-01 at 17:01 +0200, Andrea Mayer wrote:
> This selftest is designed for testing the H.Encaps.Red behavior. It
> instantiates a virtual network composed of several nodes: hosts and SRv6
> routers. Each node is realized using a network namespace that is
> properly interconnected to others through veth pairs.
> The test considers SRv6 routers implementing L3 VPNs leveraged by hosts
> for communicating with each other. Such routers make use of the SRv6
> H.Encaps.Red behavior for applying SRv6 policies to L3 traffic coming
> from hosts.
> 
> The correct execution of the behavior is verified through reachability
> tests carried out between hosts belonging to the same VPN.
> 
> Signed-off-by: Andrea Mayer <andrea.mayer@xxxxxxxxxxx>
> ---
>  tools/testing/selftests/net/Makefile          |   1 +
>  .../net/srv6_hencap_red_l3vpn_test.sh         | 742 ++++++++++++++++++
>  2 files changed, 743 insertions(+)
>  create mode 100755 tools/testing/selftests/net/srv6_hencap_red_l3vpn_test.sh
> 
> diff --git a/tools/testing/selftests/net/Makefile b/tools/testing/selftests/net/Makefile
> index ddad703ace34..3b0e9bef196b 100644
> --- a/tools/testing/selftests/net/Makefile
> +++ b/tools/testing/selftests/net/Makefile
> @@ -35,6 +35,7 @@ TEST_PROGS += cmsg_time.sh cmsg_ipv6.sh
>  TEST_PROGS += srv6_end_dt46_l3vpn_test.sh
>  TEST_PROGS += srv6_end_dt4_l3vpn_test.sh
>  TEST_PROGS += srv6_end_dt6_l3vpn_test.sh
> +TEST_PROGS += srv6_hencap_red_l3vpn_test.sh
>  TEST_PROGS += vrf_strict_mode_test.sh
>  TEST_PROGS += arp_ndisc_evict_nocarrier.sh
>  TEST_PROGS += ndisc_unsolicited_na_test.sh
> diff --git a/tools/testing/selftests/net/srv6_hencap_red_l3vpn_test.sh b/tools/testing/selftests/net/srv6_hencap_red_l3vpn_test.sh
> new file mode 100755
> index 000000000000..3b97f187b189
> --- /dev/null
> +++ b/tools/testing/selftests/net/srv6_hencap_red_l3vpn_test.sh
> @@ -0,0 +1,742 @@
> +#!/bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +#
> +# author: Andrea Mayer <andrea.mayer@xxxxxxxxxxx>
> +#
> +# This script is designed for testing the SRv6 H.Encaps.Red behavior.
> +#
> +# Below is depicted the IPv6 network of an operator which offers advanced
> +# IPv4/IPv6 VPN services to hosts, enabling them to communicate with each
> +# other.
> +# In this example, hosts hs-1 and hs-2 are connected through an IPv4/IPv6 VPN
> +# service, while hs-3 and hs-4 are connected using an IPv6 only VPN.
> +#
> +# Routers rt-1,rt-2,rt-3 and rt-4 implement IPv4/IPv6 L3 VPN services
> +# leveraging the SRv6 architecture. The key components for such VPNs are:
> +#
> +#   i) The SRv6 H.Encaps.Red behavior applies SRv6 Policies on traffic received
> +#      by connected hosts, initiating the VPN tunnel. Such a behavior is an
> +#      optimization of the SRv6 H.Encap aiming to reduce the length of the SID
> +#      List carried in the pushed SRH. Specifically, the H.Encaps.Red removes
> +#      the first SID contained in the SID List (i.e. SRv6 Policy) by storing it
> +#      into the IPv6 Destination Address. When a SRv6 Policy is made of only one
> +#      SID, the SRv6 H.Encaps.Red behavior omits the SRH at all and pushes that
> +#      SID directly into the IPv6 DA;
> +#
> +#  ii) The SRv6 End behavior advances the active SID in the SID List carried by
> +#      the SRH;
> +#
> +# iii) The SRv6 End.DT46 behavior is used for removing the SRv6 Policy and,
> +#      thus, it terminates the VPN tunnel. Such a behavior is capable of
> +#      handling, at the same time, both tunneled IPv4 and IPv6 traffic.
> +#
> +#
> +#               cafe::1                      cafe::2
> +#              10.0.0.1                     10.0.0.2
> +#             +--------+                   +--------+
> +#             |        |                   |        |
> +#             |  hs-1  |                   |  hs-2  |
> +#             |        |                   |        |
> +#             +---+----+                   +--- +---+
> +#    cafe::/64    |                             |      cafe::/64
> +#  10.0.0.0/24    |                             |    10.0.0.0/24
> +#             +---+----+                   +----+---+
> +#             |        |  fcf0:0:1:2::/64  |        |
> +#             |  rt-1  +-------------------+  rt-2  |
> +#             |        |                   |        |
> +#             +---+----+                   +----+---+
> +#                 |      .               .      |
> +#                 |  fcf0:0:1:3::/64   .        |
> +#                 |          .       .          |
> +#                 |            .   .            |
> +# fcf0:0:1:4::/64 |              .              | fcf0:0:2:3::/64
> +#                 |            .   .            |
> +#                 |          .       .          |
> +#                 |  fcf0:0:2:4::/64   .        |
> +#                 |      .               .      |
> +#             +---+----+                   +----+---+
> +#             |        |                   |        |
> +#             |  rt-4  +-------------------+  rt-3  |
> +#             |        |  fcf0:0:3:4::/64  |        |
> +#             +---+----+                   +----+---+
> +#    cafe::/64    |                             |      cafe::/64
> +#  10.0.0.0/24    |                             |    10.0.0.0/24
> +#             +---+----+                   +--- +---+
> +#             |        |                   |        |
> +#             |  hs-4  |                   |  hs-3  |
> +#             |        |                   |        |
> +#             +--------+                   +--------+
> +#               cafe::4                      cafe::3
> +#              10.0.0.4                     10.0.0.3
> +#
> +#
> +# Every fcf0:0:x:y::/64 network interconnects the SRv6 routers rt-x with rt-y
> +# in the IPv6 operator network.
> +#
> +# Local SID table
> +# ===============
> +#
> +# Each SRv6 router is configured with a Local SID table in which SIDs are
> +# stored. Considering the given SRv6 router rt-x, at least two SIDs are
> +# configured in the Local SID table:
> +#
> +#   Local SID table for SRv6 router rt-x
> +#   +----------------------------------------------------------+
> +#   |fcff:x:e is associated with the SRv6 End behavior         |
> +#   |fcff:x:d46 is associated with the SRv6 End.DT46 behavior  |
> +#   +----------------------------------------------------------+
> +#
> +# The fcff:/16 prefix is reserved by the operator for implementing SRv6 VPN
> +# services. Reachability of SIDs is ensured by proper configuration of the IPv6
> +# operator's network and SRv6 routers.
> +#
> +# # SRv6 Policies
> +# ===============
> +#
> +# An SRv6 ingress router applies SRv6 policies to the traffic received from a
> +# connected host. SRv6 policy enforcement consists of encapsulating the
> +# received traffic into a new IPv6 packet with a given SID List contained in
> +# the SRH.
> +#
> +# IPv4/IPv6 VPN between hs-1 and hs-2
> +# -----------------------------------
> +#
> +# Hosts hs-1 and hs-2 are connected using dedicated IPv4/IPv6 VPNs.
> +# Specifically, packets generated from hs-1 and directed towards hs-2 are
> +# handled by rt-1 which applies the following SRv6 Policies:
> +#
> +#   i.a) IPv6 traffic, SID List=fcff:3::e,fcff:4::e,fcff:2::d46
> +#  ii.a) IPv4 traffic, SID List=fcff:2::d46
> +#
> +# Policy (i.a) steers tunneled IPv6 traffic through SRv6 routers
> +# rt-3,rt-4,rt-2. Instead, Policy (ii.b) steers tunneled IPv4 traffic through
> +# rt-2.
> +# The H.Encaps.Red reduces the SID List (i.a) carried in SRH by removing the
> +# first SID (fcff:3::e) and pushing it into the IPv6 DA. In case of IPv4
> +# traffic, the H.Encaps.Red omits the presence of SRH at all, since the SID
> +# List (ii.a) consists of only one SID that can be stored directly in the IPv6
> +# DA.
> +#
> +# On the reverse path (i.e. from hs-2 to hs-1), rt-2 applies the following
> +# policies:
> +#
> +#   i.b) IPv6 traffic, SID List=fcff:1:d46
> +#  ii.b) IPv4 traffic, SID List=fcff:4::e,fcff:3::e,fcff:1::d46
> +#
> +# Policy (i.b) steers tunneled IPv6 traffic through the SRv6 router rt-1.
> +# Conversely, Policy (ii.b) steers tunneled IPv4 traffic through SRv6 routers
> +# rt-4,rt-3,rt-1.
> +# The H.Encaps.Red omits the SRH at all in case of (i.b) by pushing the single
> +# SID (fcff::1:d46) inside the IPv6 DA.
> +# The H.Encaps.Red reduces the SID List (ii.b) in the SRH by removing the first
> +# SID (fcff:4::e) and pushing it into the IPv6 DA.
> +#
> +# In summary:
> +#  * hs-1 -> hs-2 |IPv6 DA=fcff:3::e|SRH SIDs=fcff:4::e,fcff:2::d46|IPv6|...| (i.a)
> +#  * hs-1 -> hs-2 |IPv6 DA=fcff:2::d46|IPv4|...|                              (ii.a)
> +#
> +#  * hs-2 -> hs-1 |IPv6 DA=fcff:1::d46|IPv6|...|                              (i.b)
> +#  * hs-2 -> hs-1 |IPv6 DA=fcff:4::e|SRH SIDs=fcff:3::e,fcff:1::d46|IPv4|...| (ii.b)
> +#
> +#
> +# IPv6 VPN between hs-3 and hs-4
> +# ------------------------------
> +#
> +# Hosts hs-3 and hs-4 are connected using a dedicated IPv6 only VPN.
> +# Specifically, packets generated from hs-3 and directed towards hs-4 are
> +# handled by rt-3 which applies the following SRv6 Policy:
> +#
> +#  i.c) IPv6 traffic, SID List=fcff:2::e,fcff:4::d46
> +#
> +# Policy (i.c) steers tunneled IPv6 traffic through SRv6 routers rt-2,rt-4.
> +# The H.Encaps.Red reduces the SID List (i.c) carried in SRH by pushing the
> +# first SID (fcff:2::e) in the IPv6 DA.
> +#
> +# On the reverse path (i.e. from hs-4 to hs-3) the router rt-4 applies the
> +# following SRv6 Policy:
> +#
> +#  i.d) IPv6 traffic, SID List=fcff:1::e,fcff:3::d46.
> +#
> +# Policy (i.d) steers tunneled IPv6 traffic through SRv6 routers rt-1,rt-3.
> +# The H.Encaps.Red reduces the SID List (i.d) carried in SRH by pushing the
> +# first SID (fcff:1::e) in the IPv6 DA.
> +#
> +# In summary:
> +#  * hs-3 -> hs-4 |IPv6 DA=fcff:2::e|SRH SIDs=fcff:4::d46|IPv6|...| (i.c)
> +#  * hs-4 -> hs-3 |IPv6 DA=fcff:1::e|SRH SIDs=fcff:3::d46|IPv6|...| (i.d)
> +#
> +
> +# Kselftest framework requirement - SKIP code is 4.
> +ksft_skip=4
> +
> +readonly VRF_TID=100
> +readonly LOCALSID_TABLE_ID=90
> +readonly IPv6_RT_NETWORK=fcf0:0
> +readonly IPv6_HS_NETWORK=cafe
> +readonly IPv4_HS_NETWORK=10.0.0
> +readonly VPN_LOCATOR_SERVICE=fcff
> +readonly END_FUNC=000e
> +readonly DT46_FUNC=0d46
> +PING_TIMEOUT_SEC=4
> +
> +# global vars initialized during the setup of the selftest network
> +ROUTERS=''
> +HOSTS=''
> +
> +ret=0
> +
> +PAUSE_ON_FAIL=${PAUSE_ON_FAIL:=no}
> +
> +log_test()
> +{
> +	local rc=$1
> +	local expected=$2
> +	local msg="$3"
> +
> +	if [ ${rc} -eq ${expected} ]; then
> +		nsuccess=$((nsuccess+1))
> +		printf "\n    TEST: %-60s  [ OK ]\n" "${msg}"
> +	else
> +		ret=1
> +		nfail=$((nfail+1))
> +		printf "\n    TEST: %-60s  [FAIL]\n" "${msg}"
> +		if [ "${PAUSE_ON_FAIL}" = "yes" ]; then
> +			echo
> +			echo "hit enter to continue, 'q' to quit"
> +			read a
> +			[ "$a" = "q" ] && exit 1
> +		fi
> +	fi
> +}
> +
> +print_log_test_results()
> +{
> +	if [ "$TESTS" != "none" ]; then
> +		printf "\nTests passed: %3d\n" ${nsuccess}
> +		printf "Tests failed: %3d\n"   ${nfail}
> +	fi
> +}
> +
> +log_section()
> +{
> +	echo
> +	echo "################################################################################"
> +	echo "TEST SECTION: $*"
> +	echo "################################################################################"
> +}
> +
> +test_command_or_ksft_skip()
> +{
> +	local cmd="$1"
> +
> +	if [ ! -x "$(command -v "${cmd}")" ]; then
> +		echo "SKIP: Could not run test without \"${cmd}\" tool";
> +		exit ${ksft_skip}
> +	fi
> +}
> +
> +cleanup()
> +{
> +	local ifnames
> +	local dev
> +
> +	ifnames="$(ip -o link show | grep -oE "veth-rt-[0-9]+-[0-9]" | sort -n | uniq)"
> +
> +	# destroy any pending device
> +	for dev in ${ifnames}; do
> +		ip link del ${dev} || true
> +	done

It's better if you create/place all the virtual devices you need in
some netns: the cleanup will be easier, and the self-test will not be
impacted by some unexpected configuration in the main netns.

> +
> +	# destroy routers rt-* and hosts hs-*
> +	for ns in $(ip netns show | grep -E 'rt-*|hs-*'); do

It's better if you add to your netns name some random suffix to avoid
possible conflicts with unexpected system configuration. 

> +		ip netns del ${ns} || true
> +	done
> +}
> +
> +add_link_rt_pairs()
> +{
> +	local rt=$1
> +	local rt_neighs="$2"
> +	local neigh
> +
> +	for neigh in ${rt_neighs}; do
> +		ip link add veth-rt-${rt}-${neigh} type veth \
> +			peer name veth-rt-${neigh}-${rt}
> +	done
> +}
> +
> +get_network_prefix()
> +{
> +	local rt=$1
> +	local neigh=$2
> +	local p=${rt}
> +	local q=${neigh}
> +
> +	if [ "${p}" -gt "${q}" ]; then
> +		p=${q}; q=${rt};
> +	fi
> +
> +	echo "${IPv6_RT_NETWORK}:${p}:${q}"
> +}
> +
> +# Setup the basic networking for the routers
> +setup_rt_networking()
> +{
> +	local rt=$1
> +	local rt_neighs="$2"
> +	local nsname=rt-${rt}
> +	local net_prefix
> +	local devname
> +	local neigh
> +
> +	ip netns add ${nsname}
> +
> +	for neigh in ${rt_neighs}; do
> +		devname=veth-rt-${rt}-${neigh}
> +		ip link set ${devname} netns ${nsname}
> +
> +		net_prefix="$(get_network_prefix ${rt} ${neigh})"
> +
> +		ip -netns ${nsname} addr add ${net_prefix}::${rt}/64 \
> +			dev ${devname} nodad
> +
> +		ip -netns ${nsname} link set ${devname} up
> +	done
> +
> +	ip -netns ${nsname} link set lo up
> +
> +	ip netns exec ${nsname} sysctl -wq net.ipv6.conf.all.accept_dad=0
> +	ip netns exec ${nsname} sysctl -wq net.ipv6.conf.default.accept_dad=0
> +	ip netns exec ${nsname} sysctl -wq net.ipv6.conf.all.forwarding=1
> +
> +	ip netns exec ${nsname} sysctl -wq net.ipv4.conf.all.rp_filter=0
> +	ip netns exec ${nsname} sysctl -wq net.ipv4.conf.default.rp_filter=0
> +	ip netns exec ${nsname} sysctl -wq net.ipv4.ip_forward=1
> +}
> +
> +# Setup local SIDs for an SRv6 router
> +setup_rt_local_sids()
> +{
> +	local rt=$1
> +	local rt_neighs="$2"
> +	local nsname=rt-${rt}
> +	local rtveth=veth-t${VRF_TID}
> +	local net_prefix
> +	local devname
> +	local neigh
> +
> +	for neigh in ${rt_neighs}; do
> +		devname=veth-rt-${rt}-${neigh}
> +
> +		net_prefix="$(get_network_prefix ${rt} ${neigh})"
> +
> +		# set underlay network routes for SIDs reachability
> +		ip -netns ${nsname} -6 route add ${VPN_LOCATOR_SERVICE}:${neigh}::/32 \
> +			table ${LOCALSID_TABLE_ID} \
> +			via ${net_prefix}::${neigh} dev ${devname}
> +	done
> +
> +	# Local End behavior (note that "dev" is dummy and the VRF is chosen
> +	# for the sake of simplicity).
> +	ip -netns ${nsname} -6 route add ${VPN_LOCATOR_SERVICE}:${rt}::${END_FUNC} \
> +		table ${LOCALSID_TABLE_ID} \
> +		encap seg6local action End count dev vrf-${VRF_TID}
> +
> +	# Local End.DT46 behavior
> +	ip -netns ${nsname} -6 route add ${VPN_LOCATOR_SERVICE}:${rt}::${DT46_FUNC} \
> +		table ${LOCALSID_TABLE_ID} \
> +		encap seg6local action End.DT46 vrftable ${VRF_TID} count dev vrf-${VRF_TID}
> +
> +	# all SIDs for VPNs start with a common locator. Routes and SRv6
> +	# Endpoint behaviors instaces are grouped together in the 'localsid'
> +	# table.
> +	ip -netns ${nsname} -6 rule add \
> +			to ${VPN_LOCATOR_SERVICE}::/16 \
> +			lookup ${LOCALSID_TABLE_ID} prio 999
> +
> +	# set default routes to unreachable for both ipv4 and ipv6
> +	ip -netns ${nsname} -6 route add unreachable default metric 4278198272 \
> +		vrf vrf-${VRF_TID}
> +
> +	ip -netns ${nsname} -4 route add unreachable default metric 4278198272 \
> +		vrf vrf-${VRF_TID}
> +}
> +
> +# build and install the SRv6 policy into the ingress SRv6 router.
> +# args:
> +#  $1 - destination host (i.e. cafe::x host)
> +#  $2 - SRv6 router configured for enforcing the SRv6 Policy
> +#  $3 - SRv6 routers configured for steering traffic (End behaviors)
> +#  $4 - SRv6 router configured for removing the SRv6 Policy (router connected
> +#       to the destination host)
> +#  $5 - encap mode (full or red)
> +#  $6 - traffic type (IPv6 or IPv4)
> +__setup_rt_policy()
> +{
> +	local dst=$1
> +	local encap=$2
> +	local end_rts="$3"
> +	local dec_rt=$4
> +	local mode="$5"
> +	local traffic=$6
> +	local nsname=rt-${encap}
> +	local rtveth=veth-t${VRF_TID}
> +	local policy=''
> +	local n
> +
> +	for n in ${end_rts}; do
> +		policy=${policy}"${VPN_LOCATOR_SERVICE}:${n}::${END_FUNC},"
> +	done
> +
> +	policy=${policy}"${VPN_LOCATOR_SERVICE}:${dec_rt}::${DT46_FUNC}"
> +
> +	# add SRv6 policy to incoming traffic sent by attached hosts
> +	if [ "${traffic}" -eq 6 ]; then
> +		ip -netns ${nsname} -6 route add ${IPv6_HS_NETWORK}::${dst} vrf vrf-${VRF_TID} \
> +			encap seg6 mode ${mode} segs ${policy} dev vrf-${VRF_TID}
> +
> +		ip -netns ${nsname} -6 neigh add proxy ${IPv6_HS_NETWORK}::${dst} dev ${rtveth}
> +	else
> +		# "dev" must be different from the one where the packet is
> +		# received, otherwise the proxy arp does not work.
> +		ip -netns ${nsname} -4 route add ${IPv4_HS_NETWORK}.${dst} vrf vrf-${VRF_TID} \
> +			encap seg6 mode ${mode} segs ${policy} dev vrf-${VRF_TID}
> +	fi
> +}
> +
> +# see __setup_rt_policy
> +setup_rt_policy_ipv6()
> +{
> +	__setup_rt_policy "$1" "$2" "$3" "$4" "$5" 6
> +}
> +
> +#see __setup_rt_policy
> +setup_rt_policy_ipv4()
> +{
> +	__setup_rt_policy "$1" "$2" "$3" "$4" "$5" 4
> +}
> +
> +setup_hs()
> +{
> +	local hs=$1
> +	local rt=$2
> +	local hsname=hs-${hs}
> +	local rtname=rt-${rt}
> +	local rtveth=veth-t${VRF_TID}
> +
> +	# set the networking for the host
> +	ip netns add ${hsname}
> +
> +	ip netns exec ${hsname} sysctl -wq net.ipv6.conf.all.accept_dad=0
> +	ip netns exec ${hsname} sysctl -wq net.ipv6.conf.default.accept_dad=0
> +
> +	ip -netns ${hsname} link add veth0 type veth peer name ${rtveth}
> +	ip -netns ${hsname} link set ${rtveth} netns ${rtname}
> +	ip -netns ${hsname} addr add ${IPv6_HS_NETWORK}::${hs}/64 dev veth0 nodad
> +	ip -netns ${hsname} addr add ${IPv4_HS_NETWORK}.${hs}/24 dev veth0
> +	ip -netns ${hsname} link set veth0 up
> +	ip -netns ${hsname} link set lo up
> +
> +	# configure the VRF on the router which is directly connected to the
> +	# source host.
> +	ip -netns ${rtname} link add vrf-${VRF_TID} type vrf table ${VRF_TID}
> +	ip -netns ${rtname} link set vrf-${VRF_TID} up
> +
> +	# enslave the veth-tX interface to the vrf-X in the access router
> +	ip -netns ${rtname} link set ${rtveth} master vrf-${VRF_TID}
> +	ip -netns ${rtname} addr add ${IPv6_HS_NETWORK}::254/64 dev ${rtveth} nodad
> +	ip -netns ${rtname} addr add ${IPv4_HS_NETWORK}.254/24 dev ${rtveth}
> +	ip -netns ${rtname} link set ${rtveth} up
> +
> +	ip netns exec ${rtname} sysctl -wq net.ipv6.conf.${rtveth}.proxy_ndp=1
> +	ip netns exec ${rtname} sysctl -wq net.ipv4.conf.${rtveth}.proxy_arp=1
> +
> +	# disable the rp_filter otherwise the kernel gets confused about how
> +	# to route decap ipv4 packets.
> +	ip netns exec ${rtname} sysctl -wq net.ipv4.conf.${rtveth}.rp_filter=0
> +
> +	ip netns exec ${rtname} sh -c "echo 1 > /proc/sys/net/vrf/strict_mode"
> +}
> +
> +setup()
> +{
> +	# set up the links for connecting routers
> +	add_link_rt_pairs 1 "2 3 4"
> +	add_link_rt_pairs 2 "3 4"
> +	add_link_rt_pairs 3 "4"
> +
> +	# set up the basic connectivity of routers and routes required for
> +	# reachability of SIDs.
> +	ROUTERS="1 2 3 4"
> +	setup_rt_networking 1 "2 3 4"
> +	setup_rt_networking 2 "1 3 4"
> +	setup_rt_networking 3 "1 2 4"
> +	setup_rt_networking 4 "1 2 3"
> +
> +	# set up the hosts connected to routers
> +	HOSTS="1 2 3 4"
> +	setup_hs 1 1
> +	setup_hs 2 2
> +	setup_hs 3 3
> +	setup_hs 4 4
> +
> +	# set up default SRv6 Endpoints (i.e. SRv6 End and SRv6 End.DT46)
> +	setup_rt_local_sids 1 "2 3 4"
> +	setup_rt_local_sids 2 "1 3 4"
> +	setup_rt_local_sids 3 "1 2 4"
> +	setup_rt_local_sids 4 "1 2 3"
> +
> +	# set up SRv6 policies
> +
> +	# create an IPv6 VPN between hosts hs-1 and hs-2.
> +	# the network path between hs-1 and hs-2 traverses several routers
> +	# depending on the direction of traffic.
> +	#
> +	# Direction hs-1 -> hs-2 (H.Encaps.Red)
> +	#  - rt-3,rt-4 (SRv6 End behaviors)
> +	#  - rt-2 (SRv6 End.DT46 behavior)
> +	#
> +	# Direction hs-2 -> hs-1 (H.Encaps.Red)
> +	#  - rt-1 (SRv6 End.DT46 behavior)
> +	setup_rt_policy_ipv6 2 1 "3 4" 2 encap.red
> +	setup_rt_policy_ipv6 1 2 "" 1 encap.red
> +
> +	# create an IPv4 VPN between hosts hs-1 and hs-2
> +	# the network path between hs-1 and hs-2 traverses several routers
> +	# depending on the direction of traffic.
> +	#
> +	# Direction hs-1 -> hs-2 (H.Encaps.Red)
> +	# - rt-2 (SRv6 End.DT46 behavior)
> +	#
> +	# Direction hs-2 -> hs-1 (H.Encaps.Red)
> +	#  - rt-4,rt-3 (SRv6 End behaviors)
> +	#  - rt-1 (SRv6 End.DT46 behavior)
> +	setup_rt_policy_ipv4 2 1 "" 2 encap.red
> +	setup_rt_policy_ipv4 1 2 "4 3" 1 encap.red
> +
> +	# create an IPv6 VPN between hosts hs-3 and hs-4
> +	# the network path between hs-3 and hs-4 traverses several routers
> +	# depending on the direction of traffic.
> +	#
> +	# Direction hs-3 -> hs-4 (H.Encaps.Red)
> +	# - rt-2 (SRv6 End Behavior)
> +	# - rt-4 (SRv6 End.DT46 behavior)
> +	#
> +	# Direction hs-4 -> hs-3 (H.Encaps.Red)
> +	#  - rt-1 (SRv6 End behavior)
> +	#  - rt-3 (SRv6 End.DT46 behavior)
> +	setup_rt_policy_ipv6 4 3 "2" 4 encap.red
> +	setup_rt_policy_ipv6 3 4 "1" 3 encap.red
> +}
> +
> +check_rt_connectivity()
> +{
> +	local rtsrc=$1
> +	local rtdst=$2
> +	local prefix
> +
> +	prefix="$(get_network_prefix ${rtsrc} ${rtdst})"
> +
> +	ip netns exec rt-${rtsrc} ping -c 1 -W 1 ${prefix}::${rtdst} \
> +		>/dev/null 2>&1
> +}
> +
> +check_and_log_rt_connectivity()
> +{
> +	local rtsrc=$1
> +	local rtdst=$2
> +
> +	check_rt_connectivity ${rtsrc} ${rtdst}
> +	log_test $? 0 "Routers connectivity: rt-${rtsrc} -> rt-${rtdst}"
> +}
> +
> +check_hs_ipv6_connectivity()
> +{
> +	local hssrc=$1
> +	local hsdst=$2
> +
> +	ip netns exec hs-${hssrc} ping -c 1 -W ${PING_TIMEOUT_SEC} \
> +		${IPv6_HS_NETWORK}::${hsdst} >/dev/null 2>&1
> +}
> +
> +check_hs_ipv4_connectivity()
> +{
> +	local hssrc=$1
> +	local hsdst=$2
> +
> +	ip netns exec hs-${hssrc} ping -c 1 -W ${PING_TIMEOUT_SEC} \
> +		${IPv4_HS_NETWORK}.${hsdst} >/dev/null 2>&1
> +}
> +
> +check_and_log_hs2gw_connectivity()
> +{
> +	local hssrc=$1
> +
> +	check_hs_ipv6_connectivity ${hssrc} 254
> +	log_test $? 0 "IPv6 Hosts connectivity: hs-${hssrc} -> gw"
> +
> +	check_hs_ipv4_connectivity ${hssrc} 254
> +	log_test $? 0 "IPv4 Hosts connectivity: hs-${hssrc} -> gw"
> +}
> +
> +check_and_log_hs_ipv6_connectivity()
> +{
> +	local hssrc=$1
> +	local hsdst=$2
> +
> +	check_hs_ipv6_connectivity ${hssrc} ${hsdst}
> +	log_test $? 0 "IPv6 Hosts connectivity: hs-${hssrc} -> hs-${hsdst}"
> +}
> +
> +check_and_log_hs_ipv4_connectivity()
> +{
> +	local hssrc=$1
> +	local hsdst=$2
> +
> +	check_hs_ipv4_connectivity ${hssrc} ${hsdst}
> +	log_test $? 0 "IPv4 Hosts connectivity: hs-${hssrc} -> hs-${hsdst}"
> +}
> +
> +check_and_log_hs_connectivity()
> +{
> +	local hssrc=$1
> +	local hsdst=$2
> +
> +	check_and_log_hs_ipv4_connectivity ${hssrc} ${hsdst}
> +	check_and_log_hs_ipv6_connectivity ${hssrc} ${hsdst}
> +}
> +
> +check_and_log_hs_ipv6_isolation()
> +{
> +	local hssrc=$1
> +	local hsdst=$2
> +
> +	check_hs_ipv6_connectivity ${hssrc} ${hsdst}
> +	log_test $? 1 "IPv6 Hosts isolation: hs-${hssrc} -X-> hs-${hsdst}"
> +}
> +
> +check_and_log_hs_ipv4_isolation()
> +{
> +	local hssrc=$1
> +	local hsdst=$2
> +
> +	check_hs_ipv4_connectivity ${hssrc} ${hsdst}
> +	log_test $? 1 "IPv4 Hosts isolation: hs-${hssrc} -X-> hs-${hsdst}"
> +}
> +
> +check_and_log_hs_isolation()
> +{
> +	local hssrc=$1
> +	local hsdst=$2
> +
> +	check_and_log_hs_ipv6_isolation ${hssrc} ${hsdst}
> +	check_and_log_hs_ipv4_isolation ${hssrc} ${hsdst}
> +}
> +
> +router_tests()
> +{
> +	local i
> +	local j
> +
> +	log_section "IPv6 routers connectivity test"
> +
> +	for i in ${ROUTERS}; do
> +		for j in ${ROUTERS}; do
> +			if [ ${i} -eq ${j} ]; then
> +				continue
> +			fi
> +
> +			check_and_log_rt_connectivity ${i} ${j}
> +		done
> +	done
> +}
> +
> +host2gateway_tests()
> +{
> +	local hs
> +
> +	log_section "IPv4/IPv6 connectivity test among hosts and gateways"
> +
> +	for hs in ${HOSTS}; do
> +		check_and_log_hs2gw_connectivity ${hs}
> +	done
> +}
> +
> +host_vpn_tests()
> +{
> +	log_section "SRv6 VPN connectivity test hosts (h1 <-> h2, IPv4/IPv6)"
> +
> +	check_and_log_hs_connectivity 1 2
> +	check_and_log_hs_connectivity 2 1
> +
> +	log_section "SRv6 VPN connectivity test hosts (h3 <-> h4, IPv6 only)"
> +
> +	check_and_log_hs_ipv6_connectivity 3 4
> +	check_and_log_hs_ipv6_connectivity 4 3
> +}
> +
> +host_vpn_isolation_tests()
> +{
> +	local l1="1 2"
> +	local l2="3 4"
> +	local tmp
> +	local i
> +	local j
> +	local k
> +
> +	log_section "SRv6 VPN isolation test among hosts"
> +
> +	for k in 0 1; do
> +		for i in ${l1}; do
> +			for j in ${l2}; do
> +				check_and_log_hs_isolation ${i} ${j}
> +			done
> +		done
> +
> +		# let us test the reverse path
> +		tmp="${l1}"; l1="${l2}"; l2="${tmp}"
> +		tmp=${t1}; t1=${t2}; t2=${tmp}
> +	done
> +
> +	log_section "SRv6 VPN isolation test among hosts (h2 <-> h4, IPv4 only)"
> +
> +	check_and_log_hs_ipv4_isolation 2 4
> +	check_and_log_hs_ipv4_isolation 4 2
> +}
> +
> +test_vrf_or_ksft_skip()
> +{
> +	modprobe vrf &>/dev/null
> +	if [ ! -e /proc/sys/net/vrf/strict_mode ]; then
> +		echo "SKIP: vrf sysctl does not exist"
> +		exit ${ksft_skip}
> +	fi
> +}
> +
> +if [ "$(id -u)" -ne 0 ];then
> +	echo "SKIP: Need root privileges"
> +	exit ${ksft_skip}
> +fi
> +
> +# required programs to carry out this selftest
> +test_command_or_ksft_skip ip
> +test_command_or_ksft_skip grep
> +test_command_or_ksft_skip sort
> +test_command_or_ksft_skip uniq
> +
> +test_vrf_or_ksft_skip
> +
> +cleanup &>/dev/null

If you use:

trap cleanup EXIT

you don't need this "strange" inital cleanup and the self-test will be
more resilient WRT unexected interruptions.

Cheers,

Paolo