1#!/bin/bash
2# SPDX-License-Identifier: GPL-2.0
3#
4# author: Andrea Mayer <andrea.mayer@uniroma2.it>
5
6# This test is designed for evaluating the new SRv6 End.DT4 behavior used for
7# implementing IPv4 L3 VPN use cases.
8#
9# Hereafter a network diagram is shown, where two different tenants (named 100
10# and 200) offer IPv4 L3 VPN services allowing hosts to communicate with each
11# other across an IPv6 network.
12#
13# Only hosts belonging to the same tenant (and to the same VPN) can communicate
14# with each other. Instead, the communication among hosts of different tenants
15# is forbidden.
16# In other words, hosts hs-t100-1 and hs-t100-2 are connected through the IPv4
17# L3 VPN of tenant 100 while hs-t200-3 and hs-t200-4 are connected using the
18# IPv4 L3 VPN of tenant 200. Cross connection between tenant 100 and tenant 200
19# is forbidden and thus, for example, hs-t100-1 cannot reach hs-t200-3 and vice
20# versa.
21#
22# Routers rt-1 and rt-2 implement IPv4 L3 VPN services leveraging the SRv6
23# architecture. The key components for such VPNs are: a) SRv6 Encap behavior,
24# b) SRv6 End.DT4 behavior and c) VRF.
25#
26# To explain how an IPv4 L3 VPN based on SRv6 works, let us briefly consider an
27# example where, within the same domain of tenant 100, the host hs-t100-1 pings
28# the host hs-t100-2.
29#
30# First of all, L2 reachability of the host hs-t100-2 is taken into account by
31# the router rt-1 which acts as an arp proxy.
32#
33# When the host hs-t100-1 sends an IPv4 packet destined to hs-t100-2, the
34# router rt-1 receives the packet on the internal veth-t100 interface. Such
35# interface is enslaved to the VRF vrf-100 whose associated table contains the
36# SRv6 Encap route for encapsulating any IPv4 packet in a IPv6 plus the Segment
37# Routing Header (SRH) packet. This packet is sent through the (IPv6) core
38# network up to the router rt-2 that receives it on veth0 interface.
39#
40# The rt-2 router uses the 'localsid' routing table to process incoming
41# IPv6+SRH packets which belong to the VPN of the tenant 100. For each of these
42# packets, the SRv6 End.DT4 behavior removes the outer IPv6+SRH headers and
43# performs the lookup on the vrf-100 table using the destination address of
44# the decapsulated IPv4 packet. Afterwards, the packet is sent to the host
45# hs-t100-2 through the veth-t100 interface.
46#
47# The ping response follows the same processing but this time the role of rt-1
48# and rt-2 are swapped.
49#
50# Of course, the IPv4 L3 VPN for tenant 200 works exactly as the IPv4 L3 VPN
51# for tenant 100. In this case, only hosts hs-t200-3 and hs-t200-4 are able to
52# connect with each other.
53#
54#
55# +-------------------+                                   +-------------------+
56# |                   |                                   |                   |
57# |  hs-t100-1 netns  |                                   |  hs-t100-2 netns  |
58# |                   |                                   |                   |
59# |  +-------------+  |                                   |  +-------------+  |
60# |  |    veth0    |  |                                   |  |    veth0    |  |
61# |  | 10.0.0.1/24 |  |                                   |  | 10.0.0.2/24 |  |
62# |  +-------------+  |                                   |  +-------------+  |
63# |        .          |                                   |         .         |
64# +-------------------+                                   +-------------------+
65#          .                                                        .
66#          .                                                        .
67#          .                                                        .
68# +-----------------------------------+   +-----------------------------------+
69# |        .                          |   |                         .         |
70# | +---------------+                 |   |                 +---------------- |
71# | |   veth-t100   |                 |   |                 |   veth-t100   | |
72# | | 10.0.0.254/24 |    +----------+ |   | +----------+    | 10.0.0.254/24 | |
73# | +-------+-------+    | localsid | |   | | localsid |    +-------+-------- |
74# |         |            |   table  | |   | |   table  |            |         |
75# |    +----+----+       +----------+ |   | +----------+       +----+----+    |
76# |    | vrf-100 |                    |   |                    | vrf-100 |    |
77# |    +---------+     +------------+ |   | +------------+     +---------+    |
78# |                    |   veth0    | |   | |   veth0    |                    |
79# |                    | fd00::1/64 |.|...|.| fd00::2/64 |                    |
80# |    +---------+     +------------+ |   | +------------+     +---------+    |
81# |    | vrf-200 |                    |   |                    | vrf-200 |    |
82# |    +----+----+                    |   |                    +----+----+    |
83# |         |                         |   |                         |         |
84# | +-------+-------+                 |   |                 +-------+-------- |
85# | |   veth-t200   |                 |   |                 |   veth-t200   | |
86# | | 10.0.0.254/24 |                 |   |                 | 10.0.0.254/24 | |
87# | +---------------+      rt-1 netns |   | rt-2 netns      +---------------- |
88# |        .                          |   |                          .        |
89# +-----------------------------------+   +-----------------------------------+
90#          .                                                         .
91#          .                                                         .
92#          .                                                         .
93#          .                                                         .
94# +-------------------+                                   +-------------------+
95# |        .          |                                   |          .        |
96# |  +-------------+  |                                   |  +-------------+  |
97# |  |    veth0    |  |                                   |  |    veth0    |  |
98# |  | 10.0.0.3/24 |  |                                   |  | 10.0.0.4/24 |  |
99# |  +-------------+  |                                   |  +-------------+  |
100# |                   |                                   |                   |
101# |  hs-t200-3 netns  |                                   |  hs-t200-4 netns  |
102# |                   |                                   |                   |
103# +-------------------+                                   +-------------------+
104#
105#
106# ~~~~~~~~~~~~~~~~~~~~~~~~~
107# | Network configuration |
108# ~~~~~~~~~~~~~~~~~~~~~~~~~
109#
110# rt-1: localsid table (table 90)
111# +-------------------------------------------------+
112# |SID              |Action                         |
113# +-------------------------------------------------+
114# |fc00:21:100::6004|apply SRv6 End.DT4 vrftable 100|
115# +-------------------------------------------------+
116# |fc00:21:200::6004|apply SRv6 End.DT4 vrftable 200|
117# +-------------------------------------------------+
118#
119# rt-1: VRF tenant 100 (table 100)
120# +---------------------------------------------------+
121# |host       |Action                                 |
122# +---------------------------------------------------+
123# |10.0.0.2   |apply seg6 encap segs fc00:12:100::6004|
124# +---------------------------------------------------+
125# |10.0.0.0/24|forward to dev veth_t100               |
126# +---------------------------------------------------+
127#
128# rt-1: VRF tenant 200 (table 200)
129# +---------------------------------------------------+
130# |host       |Action                                 |
131# +---------------------------------------------------+
132# |10.0.0.4   |apply seg6 encap segs fc00:12:200::6004|
133# +---------------------------------------------------+
134# |10.0.0.0/24|forward to dev veth_t200               |
135# +---------------------------------------------------+
136#
137#
138# rt-2: localsid table (table 90)
139# +-------------------------------------------------+
140# |SID              |Action                         |
141# +-------------------------------------------------+
142# |fc00:12:100::6004|apply SRv6 End.DT4 vrftable 100|
143# +-------------------------------------------------+
144# |fc00:12:200::6004|apply SRv6 End.DT4 vrftable 200|
145# +-------------------------------------------------+
146#
147# rt-2: VRF tenant 100 (table 100)
148# +---------------------------------------------------+
149# |host       |Action                                 |
150# +---------------------------------------------------+
151# |10.0.0.1   |apply seg6 encap segs fc00:21:100::6004|
152# +---------------------------------------------------+
153# |10.0.0.0/24|forward to dev veth_t100               |
154# +---------------------------------------------------+
155#
156# rt-2: VRF tenant 200 (table 200)
157# +---------------------------------------------------+
158# |host       |Action                                 |
159# +---------------------------------------------------+
160# |10.0.0.3   |apply seg6 encap segs fc00:21:200::6004|
161# +---------------------------------------------------+
162# |10.0.0.0/24|forward to dev veth_t200               |
163# +---------------------------------------------------+
164#
165
166# Kselftest framework requirement - SKIP code is 4.
167ksft_skip=4
168
169readonly LOCALSID_TABLE_ID=90
170readonly IPv6_RT_NETWORK=fd00
171readonly IPv4_HS_NETWORK=10.0.0
172readonly VPN_LOCATOR_SERVICE=fc00
173PING_TIMEOUT_SEC=4
174
175ret=0
176
177PAUSE_ON_FAIL=${PAUSE_ON_FAIL:=no}
178
179log_test()
180{
181	local rc=$1
182	local expected=$2
183	local msg="$3"
184
185	if [ ${rc} -eq ${expected} ]; then
186		nsuccess=$((nsuccess+1))
187		printf "\n    TEST: %-60s  [ OK ]\n" "${msg}"
188	else
189		ret=1
190		nfail=$((nfail+1))
191		printf "\n    TEST: %-60s  [FAIL]\n" "${msg}"
192		if [ "${PAUSE_ON_FAIL}" = "yes" ]; then
193			echo
194			echo "hit enter to continue, 'q' to quit"
195			read a
196			[ "$a" = "q" ] && exit 1
197		fi
198	fi
199}
200
201print_log_test_results()
202{
203	if [ "$TESTS" != "none" ]; then
204		printf "\nTests passed: %3d\n" ${nsuccess}
205		printf "Tests failed: %3d\n"   ${nfail}
206	fi
207}
208
209log_section()
210{
211	echo
212	echo "################################################################################"
213	echo "TEST SECTION: $*"
214	echo "################################################################################"
215}
216
217cleanup()
218{
219	ip link del veth-rt-1 2>/dev/null || true
220	ip link del veth-rt-2 2>/dev/null || true
221
222	# destroy routers rt-* and hosts hs-*
223	for ns in $(ip netns show | grep -E 'rt-*|hs-*'); do
224		ip netns del ${ns} || true
225	done
226}
227
228# Setup the basic networking for the routers
229setup_rt_networking()
230{
231	local rt=$1
232	local nsname=rt-${rt}
233
234	ip netns add ${nsname}
235
236	ip netns exec ${nsname} sysctl -wq net.ipv6.conf.all.accept_dad=0
237	ip netns exec ${nsname} sysctl -wq net.ipv6.conf.default.accept_dad=0
238
239	ip link set veth-rt-${rt} netns ${nsname}
240	ip -netns ${nsname} link set veth-rt-${rt} name veth0
241
242	ip -netns ${nsname} addr add ${IPv6_RT_NETWORK}::${rt}/64 dev veth0 nodad
243	ip -netns ${nsname} link set veth0 up
244	ip -netns ${nsname} link set lo up
245
246	ip netns exec ${nsname} sysctl -wq net.ipv4.ip_forward=1
247	ip netns exec ${nsname} sysctl -wq net.ipv6.conf.all.forwarding=1
248}
249
250setup_hs()
251{
252	local hs=$1
253	local rt=$2
254	local tid=$3
255	local hsname=hs-t${tid}-${hs}
256	local rtname=rt-${rt}
257	local rtveth=veth-t${tid}
258
259	# set the networking for the host
260	ip netns add ${hsname}
261
262	# disable the rp_filter otherwise the kernel gets confused about how
263	# to route decap ipv4 packets.
264	ip netns exec ${rtname} sysctl -wq net.ipv4.conf.all.rp_filter=0
265	ip netns exec ${rtname} sysctl -wq net.ipv4.conf.default.rp_filter=0
266
267	ip -netns ${hsname} link add veth0 type veth peer name ${rtveth}
268	ip -netns ${hsname} link set ${rtveth} netns ${rtname}
269	ip -netns ${hsname} addr add ${IPv4_HS_NETWORK}.${hs}/24 dev veth0
270	ip -netns ${hsname} link set veth0 up
271	ip -netns ${hsname} link set lo up
272
273	# configure the VRF for the tenant X on the router which is directly
274	# connected to the source host.
275	ip -netns ${rtname} link add vrf-${tid} type vrf table ${tid}
276	ip -netns ${rtname} link set vrf-${tid} up
277
278	# enslave the veth-tX interface to the vrf-X in the access router
279	ip -netns ${rtname} link set ${rtveth} master vrf-${tid}
280	ip -netns ${rtname} addr add ${IPv4_HS_NETWORK}.254/24 dev ${rtveth}
281	ip -netns ${rtname} link set ${rtveth} up
282
283	ip netns exec ${rtname} sysctl -wq net.ipv4.conf.${rtveth}.proxy_arp=1
284
285	ip netns exec ${rtname} sh -c "echo 1 > /proc/sys/net/vrf/strict_mode"
286}
287
288setup_vpn_config()
289{
290	local hssrc=$1
291	local rtsrc=$2
292	local hsdst=$3
293	local rtdst=$4
294	local tid=$5
295
296	local hssrc_name=hs-t${tid}-${hssrc}
297	local hsdst_name=hs-t${tid}-${hsdst}
298	local rtsrc_name=rt-${rtsrc}
299	local rtdst_name=rt-${rtdst}
300	local vpn_sid=${VPN_LOCATOR_SERVICE}:${hssrc}${hsdst}:${tid}::6004
301
302	# set the encap route for encapsulating packets which arrive from the
303	# host hssrc and destined to the access router rtsrc.
304	ip -netns ${rtsrc_name} -4 route add ${IPv4_HS_NETWORK}.${hsdst}/32 vrf vrf-${tid} \
305		encap seg6 mode encap segs ${vpn_sid} dev veth0
306	ip -netns ${rtsrc_name} -6 route add ${vpn_sid}/128 vrf vrf-${tid} \
307		via fd00::${rtdst} dev veth0
308
309	# set the decap route for decapsulating packets which arrive from
310	# the rtdst router and destined to the hsdst host.
311	ip -netns ${rtdst_name} -6 route add ${vpn_sid}/128 table ${LOCALSID_TABLE_ID} \
312		encap seg6local action End.DT4 vrftable ${tid} dev vrf-${tid}
313
314	# all sids for VPNs start with a common locator which is fc00::/16.
315	# Routes for handling the SRv6 End.DT4 behavior instances are grouped
316	# together in the 'localsid' table.
317	#
318	# NOTE: added only once
319	if [ -z "$(ip -netns ${rtdst_name} -6 rule show | \
320	    grep "to ${VPN_LOCATOR_SERVICE}::/16 lookup ${LOCALSID_TABLE_ID}")" ]; then
321		ip -netns ${rtdst_name} -6 rule add \
322			to ${VPN_LOCATOR_SERVICE}::/16 \
323			lookup ${LOCALSID_TABLE_ID} prio 999
324	fi
325}
326
327setup()
328{
329	ip link add veth-rt-1 type veth peer name veth-rt-2
330	# setup the networking for router rt-1 and router rt-2
331	setup_rt_networking 1
332	setup_rt_networking 2
333
334	# setup two hosts for the tenant 100.
335	#  - host hs-1 is directly connected to the router rt-1;
336	#  - host hs-2 is directly connected to the router rt-2.
337	setup_hs 1 1 100  #args: host router tenant
338	setup_hs 2 2 100
339
340	# setup two hosts for the tenant 200
341	#  - host hs-3 is directly connected to the router rt-1;
342	#  - host hs-4 is directly connected to the router rt-2.
343	setup_hs 3 1 200
344	setup_hs 4 2 200
345
346	# setup the IPv4 L3 VPN which connects the host hs-t100-1 and host
347	# hs-t100-2 within the same tenant 100.
348	setup_vpn_config 1 1 2 2 100  #args: src_host src_router dst_host dst_router tenant
349	setup_vpn_config 2 2 1 1 100
350
351	# setup the IPv4 L3 VPN which connects the host hs-t200-3 and host
352	# hs-t200-4 within the same tenant 200.
353	setup_vpn_config 3 1 4 2 200
354	setup_vpn_config 4 2 3 1 200
355}
356
357check_rt_connectivity()
358{
359	local rtsrc=$1
360	local rtdst=$2
361
362	ip netns exec rt-${rtsrc} ping -c 1 -W 1 ${IPv6_RT_NETWORK}::${rtdst} \
363		>/dev/null 2>&1
364}
365
366check_and_log_rt_connectivity()
367{
368	local rtsrc=$1
369	local rtdst=$2
370
371	check_rt_connectivity ${rtsrc} ${rtdst}
372	log_test $? 0 "Routers connectivity: rt-${rtsrc} -> rt-${rtdst}"
373}
374
375check_hs_connectivity()
376{
377	local hssrc=$1
378	local hsdst=$2
379	local tid=$3
380
381	ip netns exec hs-t${tid}-${hssrc} ping -c 1 -W ${PING_TIMEOUT_SEC} \
382		${IPv4_HS_NETWORK}.${hsdst} >/dev/null 2>&1
383}
384
385check_and_log_hs_connectivity()
386{
387	local hssrc=$1
388	local hsdst=$2
389	local tid=$3
390
391	check_hs_connectivity ${hssrc} ${hsdst} ${tid}
392	log_test $? 0 "Hosts connectivity: hs-t${tid}-${hssrc} -> hs-t${tid}-${hsdst} (tenant ${tid})"
393}
394
395check_and_log_hs_isolation()
396{
397	local hssrc=$1
398	local tidsrc=$2
399	local hsdst=$3
400	local tiddst=$4
401
402	check_hs_connectivity ${hssrc} ${hsdst} ${tidsrc}
403	# NOTE: ping should fail
404	log_test $? 1 "Hosts isolation: hs-t${tidsrc}-${hssrc} -X-> hs-t${tiddst}-${hsdst}"
405}
406
407
408check_and_log_hs2gw_connectivity()
409{
410	local hssrc=$1
411	local tid=$2
412
413	check_hs_connectivity ${hssrc} 254 ${tid}
414	log_test $? 0 "Hosts connectivity: hs-t${tid}-${hssrc} -> gw (tenant ${tid})"
415}
416
417router_tests()
418{
419	log_section "IPv6 routers connectivity test"
420
421	check_and_log_rt_connectivity 1 2
422	check_and_log_rt_connectivity 2 1
423}
424
425host2gateway_tests()
426{
427	log_section "IPv4 connectivity test among hosts and gateway"
428
429	check_and_log_hs2gw_connectivity 1 100
430	check_and_log_hs2gw_connectivity 2 100
431
432	check_and_log_hs2gw_connectivity 3 200
433	check_and_log_hs2gw_connectivity 4 200
434}
435
436host_vpn_tests()
437{
438	log_section "SRv6 VPN connectivity test among hosts in the same tenant"
439
440	check_and_log_hs_connectivity 1 2 100
441	check_and_log_hs_connectivity 2 1 100
442
443	check_and_log_hs_connectivity 3 4 200
444	check_and_log_hs_connectivity 4 3 200
445}
446
447host_vpn_isolation_tests()
448{
449	local i
450	local j
451	local k
452	local tmp
453	local l1="1 2"
454	local l2="3 4"
455	local t1=100
456	local t2=200
457
458	log_section "SRv6 VPN isolation test among hosts in different tentants"
459
460	for k in 0 1; do
461		for i in ${l1}; do
462			for j in ${l2}; do
463				check_and_log_hs_isolation ${i} ${t1} ${j} ${t2}
464			done
465		done
466
467		# let us test the reverse path
468		tmp="${l1}"; l1="${l2}"; l2="${tmp}"
469		tmp=${t1}; t1=${t2}; t2=${tmp}
470	done
471}
472
473if [ "$(id -u)" -ne 0 ];then
474	echo "SKIP: Need root privileges"
475	exit $ksft_skip
476fi
477
478if [ ! -x "$(command -v ip)" ]; then
479	echo "SKIP: Could not run test without ip tool"
480	exit $ksft_skip
481fi
482
483modprobe vrf &>/dev/null
484if [ ! -e /proc/sys/net/vrf/strict_mode ]; then
485        echo "SKIP: vrf sysctl does not exist"
486        exit $ksft_skip
487fi
488
489cleanup &>/dev/null
490
491setup
492
493router_tests
494host2gateway_tests
495host_vpn_tests
496host_vpn_isolation_tests
497
498print_log_test_results
499
500cleanup &>/dev/null
501
502exit ${ret}
503