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+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# author: Andrea Mayer <andrea.mayer@uniroma2.it>
+
+# This test is designed for evaluating the new SRv6 End.DT4 behavior used for
+# implementing IPv4 L3 VPN use cases.
+#
+# Hereafter a network diagram is shown, where two different tenants (named 100
+# and 200) offer IPv4 L3 VPN services allowing hosts to communicate with each
+# other across an IPv6 network.
+#
+# Only hosts belonging to the same tenant (and to the same VPN) can communicate
+# with each other. Instead, the communication among hosts of different tenants
+# is forbidden.
+# In other words, hosts hs-t100-1 and hs-t100-2 are connected through the IPv4
+# L3 VPN of tenant 100 while hs-t200-3 and hs-t200-4 are connected using the
+# IPv4 L3 VPN of tenant 200. Cross connection between tenant 100 and tenant 200
+# is forbidden and thus, for example, hs-t100-1 cannot reach hs-t200-3 and vice
+# versa.
+#
+# Routers rt-1 and rt-2 implement IPv4 L3 VPN services leveraging the SRv6
+# architecture. The key components for such VPNs are: a) SRv6 Encap behavior,
+# b) SRv6 End.DT4 behavior and c) VRF.
+#
+# To explain how an IPv4 L3 VPN based on SRv6 works, let us briefly consider an
+# example where, within the same domain of tenant 100, the host hs-t100-1 pings
+# the host hs-t100-2.
+#
+# First of all, L2 reachability of the host hs-t100-2 is taken into account by
+# the router rt-1 which acts as an arp proxy.
+#
+# When the host hs-t100-1 sends an IPv4 packet destined to hs-t100-2, the
+# router rt-1 receives the packet on the internal veth-t100 interface. Such
+# interface is enslaved to the VRF vrf-100 whose associated table contains the
+# SRv6 Encap route for encapsulating any IPv4 packet in a IPv6 plus the Segment
+# Routing Header (SRH) packet. This packet is sent through the (IPv6) core
+# network up to the router rt-2 that receives it on veth0 interface.
+#
+# The rt-2 router uses the 'localsid' routing table to process incoming
+# IPv6+SRH packets which belong to the VPN of the tenant 100. For each of these
+# packets, the SRv6 End.DT4 behavior removes the outer IPv6+SRH headers and
+# performs the lookup on the vrf-100 table using the destination address of
+# the decapsulated IPv4 packet. Afterwards, the packet is sent to the host
+# hs-t100-2 through the veth-t100 interface.
+#
+# The ping response follows the same processing but this time the role of rt-1
+# and rt-2 are swapped.
+#
+# Of course, the IPv4 L3 VPN for tenant 200 works exactly as the IPv4 L3 VPN
+# for tenant 100. In this case, only hosts hs-t200-3 and hs-t200-4 are able to
+# connect with each other.
+#
+#
+# +-------------------+ +-------------------+
+# | | | |
+# | hs-t100-1 netns | | hs-t100-2 netns |
+# | | | |
+# | +-------------+ | | +-------------+ |
+# | | veth0 | | | | veth0 | |
+# | | 10.0.0.1/24 | | | | 10.0.0.2/24 | |
+# | +-------------+ | | +-------------+ |
+# | . | | . |
+# +-------------------+ +-------------------+
+# . .
+# . .
+# . .
+# +-----------------------------------+ +-----------------------------------+
+# | . | | . |
+# | +---------------+ | | +---------------- |
+# | | veth-t100 | | | | veth-t100 | |
+# | | 10.0.0.254/24 | +----------+ | | +----------+ | 10.0.0.254/24 | |
+# | +-------+-------+ | localsid | | | | localsid | +-------+-------- |
+# | | | table | | | | table | | |
+# | +----+----+ +----------+ | | +----------+ +----+----+ |
+# | | vrf-100 | | | | vrf-100 | |
+# | +---------+ +------------+ | | +------------+ +---------+ |
+# | | veth0 | | | | veth0 | |
+# | | fd00::1/64 |.|...|.| fd00::2/64 | |
+# | +---------+ +------------+ | | +------------+ +---------+ |
+# | | vrf-200 | | | | vrf-200 | |
+# | +----+----+ | | +----+----+ |
+# | | | | | |
+# | +-------+-------+ | | +-------+-------- |
+# | | veth-t200 | | | | veth-t200 | |
+# | | 10.0.0.254/24 | | | | 10.0.0.254/24 | |
+# | +---------------+ rt-1 netns | | rt-2 netns +---------------- |
+# | . | | . |
+# +-----------------------------------+ +-----------------------------------+
+# . .
+# . .
+# . .
+# . .
+# +-------------------+ +-------------------+
+# | . | | . |
+# | +-------------+ | | +-------------+ |
+# | | veth0 | | | | veth0 | |
+# | | 10.0.0.3/24 | | | | 10.0.0.4/24 | |
+# | +-------------+ | | +-------------+ |
+# | | | |
+# | hs-t200-3 netns | | hs-t200-4 netns |
+# | | | |
+# +-------------------+ +-------------------+
+#
+#
+# ~~~~~~~~~~~~~~~~~~~~~~~~~
+# | Network configuration |
+# ~~~~~~~~~~~~~~~~~~~~~~~~~
+#
+# rt-1: localsid table (table 90)
+# +-------------------------------------------------+
+# |SID |Action |
+# +-------------------------------------------------+
+# |fc00:21:100::6004|apply SRv6 End.DT4 vrftable 100|
+# +-------------------------------------------------+
+# |fc00:21:200::6004|apply SRv6 End.DT4 vrftable 200|
+# +-------------------------------------------------+
+#
+# rt-1: VRF tenant 100 (table 100)
+# +---------------------------------------------------+
+# |host |Action |
+# +---------------------------------------------------+
+# |10.0.0.2 |apply seg6 encap segs fc00:12:100::6004|
+# +---------------------------------------------------+
+# |10.0.0.0/24|forward to dev veth_t100 |
+# +---------------------------------------------------+
+#
+# rt-1: VRF tenant 200 (table 200)
+# +---------------------------------------------------+
+# |host |Action |
+# +---------------------------------------------------+
+# |10.0.0.4 |apply seg6 encap segs fc00:12:200::6004|
+# +---------------------------------------------------+
+# |10.0.0.0/24|forward to dev veth_t200 |
+# +---------------------------------------------------+
+#
+#
+# rt-2: localsid table (table 90)
+# +-------------------------------------------------+
+# |SID |Action |
+# +-------------------------------------------------+
+# |fc00:12:100::6004|apply SRv6 End.DT4 vrftable 100|
+# +-------------------------------------------------+
+# |fc00:12:200::6004|apply SRv6 End.DT4 vrftable 200|
+# +-------------------------------------------------+
+#
+# rt-2: VRF tenant 100 (table 100)
+# +---------------------------------------------------+
+# |host |Action |
+# +---------------------------------------------------+
+# |10.0.0.1 |apply seg6 encap segs fc00:21:100::6004|
+# +---------------------------------------------------+
+# |10.0.0.0/24|forward to dev veth_t100 |
+# +---------------------------------------------------+
+#
+# rt-2: VRF tenant 200 (table 200)
+# +---------------------------------------------------+
+# |host |Action |
+# +---------------------------------------------------+
+# |10.0.0.3 |apply seg6 encap segs fc00:21:200::6004|
+# +---------------------------------------------------+
+# |10.0.0.0/24|forward to dev veth_t200 |
+# +---------------------------------------------------+
+#
+
+readonly LOCALSID_TABLE_ID=90
+readonly IPv6_RT_NETWORK=fd00
+readonly IPv4_HS_NETWORK=10.0.0
+readonly VPN_LOCATOR_SERVICE=fc00
+PING_TIMEOUT_SEC=4
+
+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 "################################################################################"
+}
+
+cleanup()
+{
+ ip link del veth-rt-1 2>/dev/null || true
+ ip link del veth-rt-2 2>/dev/null || true
+
+ # destroy routers rt-* and hosts hs-*
+ for ns in $(ip netns show | grep -E 'rt-*|hs-*'); do
+ ip netns del ${ns} || true
+ done
+}
+
+# Setup the basic networking for the routers
+setup_rt_networking()
+{
+ local rt=$1
+ local nsname=rt-${rt}
+
+ ip netns add ${nsname}
+ ip link set veth-rt-${rt} netns ${nsname}
+ ip -netns ${nsname} link set veth-rt-${rt} name veth0
+
+ ip -netns ${nsname} addr add ${IPv6_RT_NETWORK}::${rt}/64 dev veth0
+ ip -netns ${nsname} link set veth0 up
+ ip -netns ${nsname} link set lo up
+
+ ip netns exec ${nsname} sysctl -wq net.ipv4.ip_forward=1
+ ip netns exec ${nsname} sysctl -wq net.ipv6.conf.all.forwarding=1
+}
+
+setup_hs()
+{
+ local hs=$1
+ local rt=$2
+ local tid=$3
+ local hsname=hs-t${tid}-${hs}
+ local rtname=rt-${rt}
+ local rtveth=veth-t${tid}
+
+ # set the networking for the host
+ ip netns add ${hsname}
+ ip -netns ${hsname} link add veth0 type veth peer name ${rtveth}
+ ip -netns ${hsname} link set ${rtveth} netns ${rtname}
+ 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 for the tenant X on the router which is directly
+ # connected to the source host.
+ ip -netns ${rtname} link add vrf-${tid} type vrf table ${tid}
+ ip -netns ${rtname} link set vrf-${tid} up
+
+ # enslave the veth-tX interface to the vrf-X in the access router
+ ip -netns ${rtname} link set ${rtveth} master vrf-${tid}
+ ip -netns ${rtname} addr add ${IPv4_HS_NETWORK}.254/24 dev ${rtveth}
+ ip -netns ${rtname} link set ${rtveth} up
+
+ ip netns exec ${rtname} sysctl -wq net.ipv4.conf.${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.all.rp_filter=0
+ 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_vpn_config()
+{
+ local hssrc=$1
+ local rtsrc=$2
+ local hsdst=$3
+ local rtdst=$4
+ local tid=$5
+
+ local hssrc_name=hs-t${tid}-${hssrc}
+ local hsdst_name=hs-t${tid}-${hsdst}
+ local rtsrc_name=rt-${rtsrc}
+ local rtdst_name=rt-${rtdst}
+ local vpn_sid=${VPN_LOCATOR_SERVICE}:${hssrc}${hsdst}:${tid}::6004
+
+ # set the encap route for encapsulating packets which arrive from the
+ # host hssrc and destined to the access router rtsrc.
+ ip -netns ${rtsrc_name} -4 route add ${IPv4_HS_NETWORK}.${hsdst}/32 vrf vrf-${tid} \
+ encap seg6 mode encap segs ${vpn_sid} dev veth0
+ ip -netns ${rtsrc_name} -6 route add ${vpn_sid}/128 vrf vrf-${tid} \
+ via fd00::${rtdst} dev veth0
+
+ # set the decap route for decapsulating packets which arrive from
+ # the rtdst router and destined to the hsdst host.
+ ip -netns ${rtdst_name} -6 route add ${vpn_sid}/128 table ${LOCALSID_TABLE_ID} \
+ encap seg6local action End.DT4 vrftable ${tid} dev vrf-${tid}
+
+ # all sids for VPNs start with a common locator which is fc00::/16.
+ # Routes for handling the SRv6 End.DT4 behavior instances are grouped
+ # together in the 'localsid' table.
+ #
+ # NOTE: added only once
+ if [ -z "$(ip -netns ${rtdst_name} -6 rule show | \
+ grep "to ${VPN_LOCATOR_SERVICE}::/16 lookup ${LOCALSID_TABLE_ID}")" ]; then
+ ip -netns ${rtdst_name} -6 rule add \
+ to ${VPN_LOCATOR_SERVICE}::/16 \
+ lookup ${LOCALSID_TABLE_ID} prio 999
+ fi
+}
+
+setup()
+{
+ ip link add veth-rt-1 type veth peer name veth-rt-2
+ # setup the networking for router rt-1 and router rt-2
+ setup_rt_networking 1
+ setup_rt_networking 2
+
+ # setup two hosts for the tenant 100.
+ # - host hs-1 is directly connected to the router rt-1;
+ # - host hs-2 is directly connected to the router rt-2.
+ setup_hs 1 1 100 #args: host router tenant
+ setup_hs 2 2 100
+
+ # setup two hosts for the tenant 200
+ # - host hs-3 is directly connected to the router rt-1;
+ # - host hs-4 is directly connected to the router rt-2.
+ setup_hs 3 1 200
+ setup_hs 4 2 200
+
+ # setup the IPv4 L3 VPN which connects the host hs-t100-1 and host
+ # hs-t100-2 within the same tenant 100.
+ setup_vpn_config 1 1 2 2 100 #args: src_host src_router dst_host dst_router tenant
+ setup_vpn_config 2 2 1 1 100
+
+ # setup the IPv4 L3 VPN which connects the host hs-t200-3 and host
+ # hs-t200-4 within the same tenant 200.
+ setup_vpn_config 3 1 4 2 200
+ setup_vpn_config 4 2 3 1 200
+}
+
+check_rt_connectivity()
+{
+ local rtsrc=$1
+ local rtdst=$2
+
+ ip netns exec rt-${rtsrc} ping -c 1 -W 1 ${IPv6_RT_NETWORK}::${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_connectivity()
+{
+ local hssrc=$1
+ local hsdst=$2
+ local tid=$3
+
+ ip netns exec hs-t${tid}-${hssrc} ping -c 1 -W ${PING_TIMEOUT_SEC} \
+ ${IPv4_HS_NETWORK}.${hsdst} >/dev/null 2>&1
+}
+
+check_and_log_hs_connectivity()
+{
+ local hssrc=$1
+ local hsdst=$2
+ local tid=$3
+
+ check_hs_connectivity ${hssrc} ${hsdst} ${tid}
+ log_test $? 0 "Hosts connectivity: hs-t${tid}-${hssrc} -> hs-t${tid}-${hsdst} (tenant ${tid})"
+}
+
+check_and_log_hs_isolation()
+{
+ local hssrc=$1
+ local tidsrc=$2
+ local hsdst=$3
+ local tiddst=$4
+
+ check_hs_connectivity ${hssrc} ${hsdst} ${tidsrc}
+ # NOTE: ping should fail
+ log_test $? 1 "Hosts isolation: hs-t${tidsrc}-${hssrc} -X-> hs-t${tiddst}-${hsdst}"
+}
+
+
+check_and_log_hs2gw_connectivity()
+{
+ local hssrc=$1
+ local tid=$2
+
+ check_hs_connectivity ${hssrc} 254 ${tid}
+ log_test $? 0 "Hosts connectivity: hs-t${tid}-${hssrc} -> gw (tenant ${tid})"
+}
+
+router_tests()
+{
+ log_section "IPv6 routers connectivity test"
+
+ check_and_log_rt_connectivity 1 2
+ check_and_log_rt_connectivity 2 1
+}
+
+host2gateway_tests()
+{
+ log_section "IPv4 connectivity test among hosts and gateway"
+
+ check_and_log_hs2gw_connectivity 1 100
+ check_and_log_hs2gw_connectivity 2 100
+
+ check_and_log_hs2gw_connectivity 3 200
+ check_and_log_hs2gw_connectivity 4 200
+}
+
+host_vpn_tests()
+{
+ log_section "SRv6 VPN connectivity test among hosts in the same tenant"
+
+ check_and_log_hs_connectivity 1 2 100
+ check_and_log_hs_connectivity 2 1 100
+
+ check_and_log_hs_connectivity 3 4 200
+ check_and_log_hs_connectivity 4 3 200
+}
+
+host_vpn_isolation_tests()
+{
+ local i
+ local j
+ local k
+ local tmp
+ local l1="1 2"
+ local l2="3 4"
+ local t1=100
+ local t2=200
+
+ log_section "SRv6 VPN isolation test among hosts in different tentants"
+
+ for k in 0 1; do
+ for i in ${l1}; do
+ for j in ${l2}; do
+ check_and_log_hs_isolation ${i} ${t1} ${j} ${t2}
+ done
+ done
+
+ # let us test the reverse path
+ tmp="${l1}"; l1="${l2}"; l2="${tmp}"
+ tmp=${t1}; t1=${t2}; t2=${tmp}
+ done
+}
+
+if [ "$(id -u)" -ne 0 ];then
+ echo "SKIP: Need root privileges"
+ exit 0
+fi
+
+if [ ! -x "$(command -v ip)" ]; then
+ echo "SKIP: Could not run test without ip tool"
+ exit 0
+fi
+
+modprobe vrf &>/dev/null
+if [ ! -e /proc/sys/net/vrf/strict_mode ]; then
+ echo "SKIP: vrf sysctl does not exist"
+ exit 0
+fi
+
+cleanup &>/dev/null
+
+setup
+
+router_tests
+host2gateway_tests
+host_vpn_tests
+host_vpn_isolation_tests
+
+print_log_test_results
+
+cleanup &>/dev/null
+
+exit ${ret}