1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
|
#!/bin/bash
# SPDX-License-Identifier: GPL-2.0
#
# author: Andrea Mayer <andrea.mayer@uniroma2.it>
# author: Paolo Lungaroni <paolo.lungaroni@uniroma2.it>
# This test is designed for evaluating the new SRv6 End.DT46 Behavior used for
# implementing IPv4/IPv6 L3 VPN use cases.
#
# The current SRv6 code in the Linux kernel only implements SRv6 End.DT4 and
# End.DT6 Behaviors which can be used respectively to support IPv4-in-IPv6 and
# IPv6-in-IPv6 VPNs. With End.DT4 and End.DT6 it is not possible to create a
# single SRv6 VPN tunnel to carry both IPv4 and IPv6 traffic.
# The SRv6 End.DT46 Behavior implementation is meant to support the
# decapsulation of IPv4 and IPv6 traffic coming from a single SRv6 tunnel.
# Therefore, the SRv6 End.DT46 Behavior in the Linux kernel greatly simplifies
# the setup and operations of SRv6 VPNs.
#
# Hereafter a network diagram is shown, where two different tenants (named 100
# and 200) offer IPv4/IPv6 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/IPv6 L3 VPN of tenant 100 while hs-t200-3 and hs-t200-4 are connected
# using the IPv4/IPv6 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/IPv6 L3 VPN services leveraging the SRv6
# architecture. The key components for such VPNs are: a) SRv6 Encap behavior,
# b) SRv6 End.DT46 Behavior and c) VRF.
#
# To explain how an IPv4/IPv6 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 a arp/ndp proxy.
#
# When the host hs-t100-1 sends an IPv6 or 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 IPv6 or 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.DT46 Behavior removes the outer IPv6+SRH headers and
# performs the lookup on the vrf-100 table using the destination address of
# the decapsulated IPv6 or 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 roles of rt-1
# and rt-2 are swapped.
#
# Of course, the IPv4/IPv6 L3 VPN for tenant 200 works exactly as the IPv4/IPv6
# 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 | |
# | | cafe::1/64 | | | | cafe::2/64 | |
# | | 10.0.0.1/24 | | | | 10.0.0.2/24 | |
# | +-------------+ | | +-------------+ |
# | . | | . |
# +-------------------+ +-------------------+
# . .
# . .
# . .
# +-----------------------------------+ +-----------------------------------+
# | . | | . |
# | +---------------+ | | +---------------- |
# | | veth-t100 | | | | veth-t100 | |
# | | cafe::254/64 | | | | cafe::254/64 | |
# | | 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 | |
# | | cafe::254/64 | | | | cafe::254/64 | |
# | | 10.0.0.254/24 | | | | 10.0.0.254/24 | |
# | +---------------+ rt-1 netns | | rt-2 netns +---------------- |
# | . | | . |
# +-----------------------------------+ +-----------------------------------+
# . .
# . .
# . .
# . .
# +-------------------+ +-------------------+
# | . | | . |
# | +-------------+ | | +-------------+ |
# | | veth0 | | | | veth0 | |
# | | cafe::3/64 | | | | cafe::4/64 | |
# | | 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::6046|apply SRv6 End.DT46 vrftable 100|
# +--------------------------------------------------+
# |fc00:21:200::6046|apply SRv6 End.DT46 vrftable 200|
# +--------------------------------------------------+
#
# rt-1: VRF tenant 100 (table 100)
# +---------------------------------------------------+
# |host |Action |
# +---------------------------------------------------+
# |cafe::2 |apply seg6 encap segs fc00:12:100::6046|
# +---------------------------------------------------+
# |cafe::/64 |forward to dev veth-t100 |
# +---------------------------------------------------+
# |10.0.0.2 |apply seg6 encap segs fc00:12:100::6046|
# +---------------------------------------------------+
# |10.0.0.0/24|forward to dev veth-t100 |
# +---------------------------------------------------+
#
# rt-1: VRF tenant 200 (table 200)
# +---------------------------------------------------+
# |host |Action |
# +---------------------------------------------------+
# |cafe::4 |apply seg6 encap segs fc00:12:200::6046|
# +---------------------------------------------------+
# |cafe::/64 |forward to dev veth-t200 |
# +---------------------------------------------------+
# |10.0.0.4 |apply seg6 encap segs fc00:12:200::6046|
# +---------------------------------------------------+
# |10.0.0.0/24|forward to dev veth-t200 |
# +---------------------------------------------------+
#
#
# rt-2: localsid table (table 90)
# +--------------------------------------------------+
# |SID |Action |
# +--------------------------------------------------+
# |fc00:12:100::6046|apply SRv6 End.DT46 vrftable 100|
# +--------------------------------------------------+
# |fc00:12:200::6046|apply SRv6 End.DT46 vrftable 200|
# +--------------------------------------------------+
#
# rt-2: VRF tenant 100 (table 100)
# +---------------------------------------------------+
# |host |Action |
# +---------------------------------------------------+
# |cafe::1 |apply seg6 encap segs fc00:21:100::6046|
# +---------------------------------------------------+
# |cafe::/64 |forward to dev veth-t100 |
# +---------------------------------------------------+
# |10.0.0.1 |apply seg6 encap segs fc00:21:100::6046|
# +---------------------------------------------------+
# |10.0.0.0/24|forward to dev veth-t100 |
# +---------------------------------------------------+
#
# rt-2: VRF tenant 200 (table 200)
# +---------------------------------------------------+
# |host |Action |
# +---------------------------------------------------+
# |cafe::3 |apply seg6 encap segs fc00:21:200::6046|
# +---------------------------------------------------+
# |cafe::/64 |forward to dev veth-t200 |
# +---------------------------------------------------+
# |10.0.0.3 |apply seg6 encap segs fc00:21:200::6046|
# +---------------------------------------------------+
# |10.0.0.0/24|forward to dev veth-t200 |
# +---------------------------------------------------+
#
readonly LOCALSID_TABLE_ID=90
readonly IPv6_RT_NETWORK=fd00
readonly IPv6_HS_NETWORK=cafe
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 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 ${nsname} addr add ${IPv6_RT_NETWORK}::${rt}/64 dev veth0 nodad
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 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 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
ip netns exec ${rtname} sysctl -wq net.ipv6.conf.all.accept_dad=0
ip netns exec ${rtname} sysctl -wq net.ipv6.conf.default.accept_dad=0
# 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 ${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.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-${rtdst}
local rtveth=veth-t${tid}
local vpn_sid=${VPN_LOCATOR_SERVICE}:${hssrc}${hsdst}:${tid}::6046
ip -netns ${rtsrc_name} -6 neigh add proxy ${IPv6_HS_NETWORK}::${hsdst} dev ${rtveth}
# set the encap route for encapsulating packets which arrive from the
# host hssrc and destined to the access router rtsrc.
ip -netns ${rtsrc_name} -6 route add ${IPv6_HS_NETWORK}::${hsdst}/128 vrf vrf-${tid} \
encap seg6 mode encap segs ${vpn_sid} dev veth0
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.DT46 vrftable ${tid} dev vrf-${tid}
# all sids for VPNs start with a common locator which is fc00::/16.
# Routes for handling the SRv6 End.DT46 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
# set default routes to unreachable for both ipv4 and ipv6
ip -netns ${rtsrc_name} -6 route add unreachable default metric 4278198272 \
vrf vrf-${tid}
ip -netns ${rtsrc_name} -4 route add unreachable default metric 4278198272 \
vrf vrf-${tid}
}
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/IPv6 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/IPv6 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_ipv6_connectivity()
{
local hssrc=$1
local hsdst=$2
local tid=$3
ip netns exec hs-t${tid}-${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
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_ipv6_connectivity ${hssrc} ${hsdst} ${tid}
log_test $? 0 "IPv6 Hosts connectivity: hs-t${tid}-${hssrc} -> hs-t${tid}-${hsdst} (tenant ${tid})"
check_hs_ipv4_connectivity ${hssrc} ${hsdst} ${tid}
log_test $? 0 "IPv4 Hosts connectivity: hs-t${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_ipv6_connectivity ${hssrc} ${hsdst} ${tidsrc}
# NOTE: ping should fail
log_test $? 1 "IPv6 Hosts isolation: hs-t${tidsrc}-${hssrc} -X-> hs-t${tiddst}-${hsdst}"
check_hs_ipv4_connectivity ${hssrc} ${hsdst} ${tidsrc}
# NOTE: ping should fail
log_test $? 1 "IPv4 Hosts isolation: hs-t${tidsrc}-${hssrc} -X-> hs-t${tiddst}-${hsdst}"
}
check_and_log_hs2gw_connectivity()
{
local hssrc=$1
local tid=$2
check_hs_ipv6_connectivity ${hssrc} 254 ${tid}
log_test $? 0 "IPv6 Hosts connectivity: hs-t${tid}-${hssrc} -> gw (tenant ${tid})"
check_hs_ipv4_connectivity ${hssrc} 254 ${tid}
log_test $? 0 "IPv4 Hosts connectivity: hs-t${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/IPv6 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}
|
