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 source lib.sh
167
168 readonly LOCALSID_TABLE_ID=90
169 readonly IPv6_RT_NETWORK=fd00
170 readonly IPv4_HS_NETWORK=10.0.0
171 readonly VPN_LOCATOR_SERVICE=fc00
172 PING_TIMEOUT_SEC=4
173
174 ret=0
175
176 PAUSE_ON_FAIL=${PAUSE_ON_FAIL:=no}
177
178 log_test()
179 {
180 local rc=$1
181 local expected=$2
182 local msg="$3"
183
184 if [ ${rc} -eq ${expected} ]; then
185 nsuccess=$((nsuccess+1))
186 printf "\n TEST: %-60s [ OK ]\n" "${msg}"
187 else
188 ret=1
189 nfail=$((nfail+1))
190 printf "\n TEST: %-60s [FAIL]\n" "${msg}"
191 if [ "${PAUSE_ON_FAIL}" = "yes" ]; then
192 echo
193 echo "hit enter to continue, 'q' to quit"
194 read a
195 [ "$a" = "q" ] && exit 1
196 fi
197 fi
198 }
199
200 print_log_test_results()
201 {
202 if [ "$TESTS" != "none" ]; then
203 printf "\nTests passed: %3d\n" ${nsuccess}
204 printf "Tests failed: %3d\n" ${nfail}
205 fi
206 }
207
208 log_section()
209 {
210 echo
211 echo "################################################################################"
212 echo "TEST SECTION: $*"
213 echo "################################################################################"
214 }
215
216 cleanup()
217 {
218 ip link del veth-rt-1 2>/dev/null || true
219 ip link del veth-rt-2 2>/dev/null || true
220
221 cleanup_all_ns
222 }
223
224 # Setup the basic networking for the routers
225 setup_rt_networking()
226 {
227 local id=$1
228 eval local nsname=\${rt_${id}}
229
230 ip netns exec ${nsname} sysctl -wq net.ipv6.conf.all.accept_dad=0
231 ip netns exec ${nsname} sysctl -wq net.ipv6.conf.default.accept_dad=0
232
233 ip link set veth-rt-${id} netns ${nsname}
234 ip -netns ${nsname} link set veth-rt-${id} name veth0
235
236 ip -netns ${nsname} addr add ${IPv6_RT_NETWORK}::${id}/64 dev veth0 nodad
237 ip -netns ${nsname} link set veth0 up
238 ip -netns ${nsname} link set lo up
239
240 ip netns exec ${nsname} sysctl -wq net.ipv4.ip_forward=1
241 ip netns exec ${nsname} sysctl -wq net.ipv6.conf.all.forwarding=1
242 }
243
244 setup_hs()
245 {
246 local hid=$1
247 local rid=$2
248 local tid=$3
249 eval local hsname=\${hs_t${tid}_${hid}}
250 eval local rtname=\${rt_${rid}}
251 local rtveth=veth-t${tid}
252
253 # disable the rp_filter otherwise the kernel gets confused about how
254 # to route decap ipv4 packets.
255 ip netns exec ${rtname} sysctl -wq net.ipv4.conf.all.rp_filter=0
256 ip netns exec ${rtname} sysctl -wq net.ipv4.conf.default.rp_filter=0
257
258 ip -netns ${hsname} link add veth0 type veth peer name ${rtveth}
259 ip -netns ${hsname} link set ${rtveth} netns ${rtname}
260 ip -netns ${hsname} addr add ${IPv4_HS_NETWORK}.${hid}/24 dev veth0
261 ip -netns ${hsname} link set veth0 up
262 ip -netns ${hsname} link set lo up
263
264 # configure the VRF for the tenant X on the router which is directly
265 # connected to the source host.
266 ip -netns ${rtname} link add vrf-${tid} type vrf table ${tid}
267 ip -netns ${rtname} link set vrf-${tid} up
268
269 # enslave the veth-tX interface to the vrf-X in the access router
270 ip -netns ${rtname} link set ${rtveth} master vrf-${tid}
271 ip -netns ${rtname} addr add ${IPv4_HS_NETWORK}.254/24 dev ${rtveth}
272 ip -netns ${rtname} link set ${rtveth} up
273
274 ip netns exec ${rtname} sysctl -wq net.ipv4.conf.${rtveth}.proxy_arp=1
275
276 ip netns exec ${rtname} sh -c "echo 1 > /proc/sys/net/vrf/strict_mode"
277 }
278
279 setup_vpn_config()
280 {
281 local hssrc=$1
282 local rtsrc=$2
283 local hsdst=$3
284 local rtdst=$4
285 local tid=$5
286
287 eval local rtsrc_name=\${rt_${rtsrc}}
288 eval local rtdst_name=\${rt_${rtdst}}
289 local vpn_sid=${VPN_LOCATOR_SERVICE}:${hssrc}${hsdst}:${tid}::6004
290
291 # set the encap route for encapsulating packets which arrive from the
292 # host hssrc and destined to the access router rtsrc.
293 ip -netns ${rtsrc_name} -4 route add ${IPv4_HS_NETWORK}.${hsdst}/32 vrf vrf-${tid} \
294 encap seg6 mode encap segs ${vpn_sid} dev veth0
295 ip -netns ${rtsrc_name} -6 route add ${vpn_sid}/128 vrf vrf-${tid} \
296 via fd00::${rtdst} dev veth0
297
298 # set the decap route for decapsulating packets which arrive from
299 # the rtdst router and destined to the hsdst host.
300 ip -netns ${rtdst_name} -6 route add ${vpn_sid}/128 table ${LOCALSID_TABLE_ID} \
301 encap seg6local action End.DT4 vrftable ${tid} dev vrf-${tid}
302
303 # all sids for VPNs start with a common locator which is fc00::/16.
304 # Routes for handling the SRv6 End.DT4 behavior instances are grouped
305 # together in the 'localsid' table.
306 #
307 # NOTE: added only once
308 if [ -z "$(ip -netns ${rtdst_name} -6 rule show | \
309 grep "to ${VPN_LOCATOR_SERVICE}::/16 lookup ${LOCALSID_TABLE_ID}")" ]; then
310 ip -netns ${rtdst_name} -6 rule add \
311 to ${VPN_LOCATOR_SERVICE}::/16 \
312 lookup ${LOCALSID_TABLE_ID} prio 999
313 fi
314 }
315
316 setup()
317 {
318 ip link add veth-rt-1 type veth peer name veth-rt-2
319 # setup the networking for router rt-1 and router rt-2
320 setup_ns rt_1 rt_2
321 setup_rt_networking 1
322 setup_rt_networking 2
323
324 # setup two hosts for the tenant 100.
325 # - host hs-1 is directly connected to the router rt-1;
326 # - host hs-2 is directly connected to the router rt-2.
327 setup_ns hs_t100_1 hs_t100_2
328 setup_hs 1 1 100 #args: host router tenant
329 setup_hs 2 2 100
330
331 # setup two hosts for the tenant 200
332 # - host hs-3 is directly connected to the router rt-1;
333 # - host hs-4 is directly connected to the router rt-2.
334 setup_ns hs_t200_3 hs_t200_4
335 setup_hs 3 1 200
336 setup_hs 4 2 200
337
338 # setup the IPv4 L3 VPN which connects the host hs-t100-1 and host
339 # hs-t100-2 within the same tenant 100.
340 setup_vpn_config 1 1 2 2 100 #args: src_host src_router dst_host dst_router tenant
341 setup_vpn_config 2 2 1 1 100
342
343 # setup the IPv4 L3 VPN which connects the host hs-t200-3 and host
344 # hs-t200-4 within the same tenant 200.
345 setup_vpn_config 3 1 4 2 200
346 setup_vpn_config 4 2 3 1 200
347 }
348
349 check_rt_connectivity()
350 {
351 local rtsrc=$1
352 local rtdst=$2
353 eval local nsname=\${rt_${rtsrc}}
354
355 ip netns exec ${nsname} ping -c 1 -W 1 ${IPv6_RT_NETWORK}::${rtdst} \
356 >/dev/null 2>&1
357 }
358
359 check_and_log_rt_connectivity()
360 {
361 local rtsrc=$1
362 local rtdst=$2
363
364 check_rt_connectivity ${rtsrc} ${rtdst}
365 log_test $? 0 "Routers connectivity: rt-${rtsrc} -> rt-${rtdst}"
366 }
367
368 check_hs_connectivity()
369 {
370 local hssrc=$1
371 local hsdst=$2
372 local tid=$3
373 eval local nsname=\${hs_t${tid}_${hssrc}}
374
375 ip netns exec ${nsname} ping -c 1 -W ${PING_TIMEOUT_SEC} \
376 ${IPv4_HS_NETWORK}.${hsdst} >/dev/null 2>&1
377 }
378
379 check_and_log_hs_connectivity()
380 {
381 local hssrc=$1
382 local hsdst=$2
383 local tid=$3
384
385 check_hs_connectivity ${hssrc} ${hsdst} ${tid}
386 log_test $? 0 "Hosts connectivity: hs-t${tid}-${hssrc} -> hs-t${tid}-${hsdst} (tenant ${tid})"
387 }
388
389 check_and_log_hs_isolation()
390 {
391 local hssrc=$1
392 local tidsrc=$2
393 local hsdst=$3
394 local tiddst=$4
395
396 check_hs_connectivity ${hssrc} ${hsdst} ${tidsrc}
397 # NOTE: ping should fail
398 log_test $? 1 "Hosts isolation: hs-t${tidsrc}-${hssrc} -X-> hs-t${tiddst}-${hsdst}"
399 }
400
401
402 check_and_log_hs2gw_connectivity()
403 {
404 local hssrc=$1
405 local tid=$2
406
407 check_hs_connectivity ${hssrc} 254 ${tid}
408 log_test $? 0 "Hosts connectivity: hs-t${tid}-${hssrc} -> gw (tenant ${tid})"
409 }
410
411 router_tests()
412 {
413 log_section "IPv6 routers connectivity test"
414
415 check_and_log_rt_connectivity 1 2
416 check_and_log_rt_connectivity 2 1
417 }
418
419 host2gateway_tests()
420 {
421 log_section "IPv4 connectivity test among hosts and gateway"
422
423 check_and_log_hs2gw_connectivity 1 100
424 check_and_log_hs2gw_connectivity 2 100
425
426 check_and_log_hs2gw_connectivity 3 200
427 check_and_log_hs2gw_connectivity 4 200
428 }
429
430 host_vpn_tests()
431 {
432 log_section "SRv6 VPN connectivity test among hosts in the same tenant"
433
434 check_and_log_hs_connectivity 1 2 100
435 check_and_log_hs_connectivity 2 1 100
436
437 check_and_log_hs_connectivity 3 4 200
438 check_and_log_hs_connectivity 4 3 200
439 }
440
441 host_vpn_isolation_tests()
442 {
443 local i
444 local j
445 local k
446 local tmp
447 local l1="1 2"
448 local l2="3 4"
449 local t1=100
450 local t2=200
451
452 log_section "SRv6 VPN isolation test among hosts in different tentants"
453
454 for k in 0 1; do
455 for i in ${l1}; do
456 for j in ${l2}; do
457 check_and_log_hs_isolation ${i} ${t1} ${j} ${t2}
458 done
459 done
460
461 # let us test the reverse path
462 tmp="${l1}"; l1="${l2}"; l2="${tmp}"
463 tmp=${t1}; t1=${t2}; t2=${tmp}
464 done
465 }
466
467 if [ "$(id -u)" -ne 0 ];then
468 echo "SKIP: Need root privileges"
469 exit $ksft_skip
470 fi
471
472 if [ ! -x "$(command -v ip)" ]; then
473 echo "SKIP: Could not run test without ip tool"
474 exit $ksft_skip
475 fi
476
477 modprobe vrf &>/dev/null
478 if [ ! -e /proc/sys/net/vrf/strict_mode ]; then
479 echo "SKIP: vrf sysctl does not exist"
480 exit $ksft_skip
481 fi
482
483 cleanup &>/dev/null
484
485 setup
486
487 router_tests
488 host2gateway_tests
489 host_vpn_tests
490 host_vpn_isolation_tests
491
492 print_log_test_results
493
494 cleanup &>/dev/null
495
496 exit ${ret}
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