1#!/bin/bash
2# SPDX-License-Identifier: GPL-2.0
3#
4# This tests basic flowtable functionality.
5# Creates following default topology:
6#
7# Originator (MTU 9000) <-Router1-> MTU 1500 <-Router2-> Responder (MTU 2000)
8# Router1 is the one doing flow offloading, Router2 has no special
9# purpose other than having a link that is smaller than either Originator
10# and responder, i.e. TCPMSS announced values are too large and will still
11# result in fragmentation and/or PMTU discovery.
12#
13# You can check with different Orgininator/Link/Responder MTU eg:
14# nft_flowtable.sh -o8000 -l1500 -r2000
15#
16
17
18# Kselftest framework requirement - SKIP code is 4.
19ksft_skip=4
20ret=0
21
22ns1in=""
23ns2in=""
24ns1out=""
25ns2out=""
26
27log_netns=$(sysctl -n net.netfilter.nf_log_all_netns)
28
29checktool (){
30	if ! $1 > /dev/null 2>&1; then
31		echo "SKIP: Could not $2"
32		exit $ksft_skip
33	fi
34}
35
36checktool "nft --version" "run test without nft tool"
37checktool "ip -Version" "run test without ip tool"
38checktool "which nc" "run test without nc (netcat)"
39checktool "ip netns add nsr1" "create net namespace"
40
41ip netns add ns1
42ip netns add ns2
43
44ip netns add nsr2
45
46cleanup() {
47	for i in 1 2; do
48		ip netns del ns$i
49		ip netns del nsr$i
50	done
51
52	rm -f "$ns1in" "$ns1out"
53	rm -f "$ns2in" "$ns2out"
54
55	[ $log_netns -eq 0 ] && sysctl -q net.netfilter.nf_log_all_netns=$log_netns
56}
57
58trap cleanup EXIT
59
60sysctl -q net.netfilter.nf_log_all_netns=1
61
62ip link add veth0 netns nsr1 type veth peer name eth0 netns ns1
63ip link add veth1 netns nsr1 type veth peer name veth0 netns nsr2
64
65ip link add veth1 netns nsr2 type veth peer name eth0 netns ns2
66
67for dev in lo veth0 veth1; do
68  for i in 1 2; do
69    ip -net nsr$i link set $dev up
70  done
71done
72
73ip -net nsr1 addr add 10.0.1.1/24 dev veth0
74ip -net nsr1 addr add dead:1::1/64 dev veth0
75
76ip -net nsr2 addr add 10.0.2.1/24 dev veth1
77ip -net nsr2 addr add dead:2::1/64 dev veth1
78
79# set different MTUs so we need to push packets coming from ns1 (large MTU)
80# to ns2 (smaller MTU) to stack either to perform fragmentation (ip_no_pmtu_disc=1),
81# or to do PTMU discovery (send ICMP error back to originator).
82# ns2 is going via nsr2 with a smaller mtu, so that TCPMSS announced by both peers
83# is NOT the lowest link mtu.
84
85omtu=9000
86lmtu=1500
87rmtu=2000
88
89usage(){
90	echo "nft_flowtable.sh [OPTIONS]"
91	echo
92	echo "MTU options"
93	echo "   -o originator"
94	echo "   -l link"
95	echo "   -r responder"
96	exit 1
97}
98
99while getopts "o:l:r:" o
100do
101	case $o in
102		o) omtu=$OPTARG;;
103		l) lmtu=$OPTARG;;
104		r) rmtu=$OPTARG;;
105		*) usage;;
106	esac
107done
108
109if ! ip -net nsr1 link set veth0 mtu $omtu; then
110	exit 1
111fi
112
113ip -net ns1 link set eth0 mtu $omtu
114
115if ! ip -net nsr2 link set veth1 mtu $rmtu; then
116	exit 1
117fi
118
119ip -net ns2 link set eth0 mtu $rmtu
120
121# transfer-net between nsr1 and nsr2.
122# these addresses are not used for connections.
123ip -net nsr1 addr add 192.168.10.1/24 dev veth1
124ip -net nsr1 addr add fee1:2::1/64 dev veth1
125
126ip -net nsr2 addr add 192.168.10.2/24 dev veth0
127ip -net nsr2 addr add fee1:2::2/64 dev veth0
128
129for i in 1 2; do
130  ip netns exec nsr$i sysctl net.ipv4.conf.veth0.forwarding=1 > /dev/null
131  ip netns exec nsr$i sysctl net.ipv4.conf.veth1.forwarding=1 > /dev/null
132
133  ip -net ns$i link set lo up
134  ip -net ns$i link set eth0 up
135  ip -net ns$i addr add 10.0.$i.99/24 dev eth0
136  ip -net ns$i route add default via 10.0.$i.1
137  ip -net ns$i addr add dead:$i::99/64 dev eth0
138  ip -net ns$i route add default via dead:$i::1
139  if ! ip netns exec ns$i sysctl net.ipv4.tcp_no_metrics_save=1 > /dev/null; then
140	echo "ERROR: Check Originator/Responder values (problem during address addition)"
141	exit 1
142  fi
143
144  # don't set ip DF bit for first two tests
145  ip netns exec ns$i sysctl net.ipv4.ip_no_pmtu_disc=1 > /dev/null
146done
147
148ip -net nsr1 route add default via 192.168.10.2
149ip -net nsr2 route add default via 192.168.10.1
150
151ip netns exec nsr1 nft -f - <<EOF
152table inet filter {
153  flowtable f1 {
154     hook ingress priority 0
155     devices = { veth0, veth1 }
156   }
157
158   chain forward {
159      type filter hook forward priority 0; policy drop;
160
161      # flow offloaded? Tag ct with mark 1, so we can detect when it fails.
162      meta oif "veth1" tcp dport 12345 flow offload @f1 counter
163
164      # use packet size to trigger 'should be offloaded by now'.
165      # otherwise, if 'flow offload' expression never offloads, the
166      # test will pass.
167      tcp dport 12345 meta length gt 200 ct mark set 1 counter
168
169      # this turns off flow offloading internally, so expect packets again
170      tcp flags fin,rst ct mark set 0 accept
171
172      # this allows large packets from responder, we need this as long
173      # as PMTUd is off.
174      # This rule is deleted for the last test, when we expect PMTUd
175      # to kick in and ensure all packets meet mtu requirements.
176      meta length gt $lmtu accept comment something-to-grep-for
177
178      # next line blocks connection w.o. working offload.
179      # we only do this for reverse dir, because we expect packets to
180      # enter slow path due to MTU mismatch of veth0 and veth1.
181      tcp sport 12345 ct mark 1 counter log prefix "mark failure " drop
182
183      ct state established,related accept
184
185      # for packets that we can't offload yet, i.e. SYN (any ct that is not confirmed)
186      meta length lt 200 oif "veth1" tcp dport 12345 counter accept
187
188      meta nfproto ipv4 meta l4proto icmp accept
189      meta nfproto ipv6 meta l4proto icmpv6 accept
190   }
191}
192EOF
193
194if [ $? -ne 0 ]; then
195	echo "SKIP: Could not load nft ruleset"
196	exit $ksft_skip
197fi
198
199# test basic connectivity
200if ! ip netns exec ns1 ping -c 1 -q 10.0.2.99 > /dev/null; then
201  echo "ERROR: ns1 cannot reach ns2" 1>&2
202  exit 1
203fi
204
205if ! ip netns exec ns2 ping -c 1 -q 10.0.1.99 > /dev/null; then
206  echo "ERROR: ns2 cannot reach ns1" 1>&2
207  exit 1
208fi
209
210if [ $ret -eq 0 ];then
211	echo "PASS: netns routing/connectivity: ns1 can reach ns2"
212fi
213
214ns1in=$(mktemp)
215ns1out=$(mktemp)
216ns2in=$(mktemp)
217ns2out=$(mktemp)
218
219make_file()
220{
221	name=$1
222
223	SIZE=$((RANDOM % (1024 * 8)))
224	TSIZE=$((SIZE * 1024))
225
226	dd if=/dev/urandom of="$name" bs=1024 count=$SIZE 2> /dev/null
227
228	SIZE=$((RANDOM % 1024))
229	SIZE=$((SIZE + 128))
230	TSIZE=$((TSIZE + SIZE))
231	dd if=/dev/urandom conf=notrunc of="$name" bs=1 count=$SIZE 2> /dev/null
232}
233
234check_transfer()
235{
236	in=$1
237	out=$2
238	what=$3
239
240	if ! cmp "$in" "$out" > /dev/null 2>&1; then
241		echo "FAIL: file mismatch for $what" 1>&2
242		ls -l "$in"
243		ls -l "$out"
244		return 1
245	fi
246
247	return 0
248}
249
250test_tcp_forwarding_ip()
251{
252	local nsa=$1
253	local nsb=$2
254	local dstip=$3
255	local dstport=$4
256	local lret=0
257
258	ip netns exec $nsb nc -w 5 -l -p 12345 < "$ns2in" > "$ns2out" &
259	lpid=$!
260
261	sleep 1
262	ip netns exec $nsa nc -w 4 "$dstip" "$dstport" < "$ns1in" > "$ns1out" &
263	cpid=$!
264
265	sleep 3
266
267	if ps -p $lpid > /dev/null;then
268		kill $lpid
269	fi
270
271	if ps -p $cpid > /dev/null;then
272		kill $cpid
273	fi
274
275	wait
276
277	if ! check_transfer "$ns1in" "$ns2out" "ns1 -> ns2"; then
278		lret=1
279	fi
280
281	if ! check_transfer "$ns2in" "$ns1out" "ns1 <- ns2"; then
282		lret=1
283	fi
284
285	return $lret
286}
287
288test_tcp_forwarding()
289{
290	test_tcp_forwarding_ip "$1" "$2" 10.0.2.99 12345
291
292	return $?
293}
294
295test_tcp_forwarding_nat()
296{
297	local lret
298
299	test_tcp_forwarding_ip "$1" "$2" 10.0.2.99 12345
300	lret=$?
301
302	if [ $lret -eq 0 ] ; then
303		test_tcp_forwarding_ip "$1" "$2" 10.6.6.6 1666
304		lret=$?
305	fi
306
307	return $lret
308}
309
310make_file "$ns1in"
311make_file "$ns2in"
312
313# First test:
314# No PMTU discovery, nsr1 is expected to fragment packets from ns1 to ns2 as needed.
315if test_tcp_forwarding ns1 ns2; then
316	echo "PASS: flow offloaded for ns1/ns2"
317else
318	echo "FAIL: flow offload for ns1/ns2:" 1>&2
319	ip netns exec nsr1 nft list ruleset
320	ret=1
321fi
322
323# delete default route, i.e. ns2 won't be able to reach ns1 and
324# will depend on ns1 being masqueraded in nsr1.
325# expect ns1 has nsr1 address.
326ip -net ns2 route del default via 10.0.2.1
327ip -net ns2 route del default via dead:2::1
328ip -net ns2 route add 192.168.10.1 via 10.0.2.1
329
330# Second test:
331# Same, but with NAT enabled.
332ip netns exec nsr1 nft -f - <<EOF
333table ip nat {
334   chain prerouting {
335      type nat hook prerouting priority 0; policy accept;
336      meta iif "veth0" ip daddr 10.6.6.6 tcp dport 1666 counter dnat ip to 10.0.2.99:12345
337   }
338
339   chain postrouting {
340      type nat hook postrouting priority 0; policy accept;
341      meta oifname "veth1" counter masquerade
342   }
343}
344EOF
345
346if test_tcp_forwarding_nat ns1 ns2; then
347	echo "PASS: flow offloaded for ns1/ns2 with NAT"
348else
349	echo "FAIL: flow offload for ns1/ns2 with NAT" 1>&2
350	ip netns exec nsr1 nft list ruleset
351	ret=1
352fi
353
354# Third test:
355# Same as second test, but with PMTU discovery enabled.
356handle=$(ip netns exec nsr1 nft -a list table inet filter | grep something-to-grep-for | cut -d \# -f 2)
357
358if ! ip netns exec nsr1 nft delete rule inet filter forward $handle; then
359	echo "FAIL: Could not delete large-packet accept rule"
360	exit 1
361fi
362
363ip netns exec ns1 sysctl net.ipv4.ip_no_pmtu_disc=0 > /dev/null
364ip netns exec ns2 sysctl net.ipv4.ip_no_pmtu_disc=0 > /dev/null
365
366if test_tcp_forwarding_nat ns1 ns2; then
367	echo "PASS: flow offloaded for ns1/ns2 with NAT and pmtu discovery"
368else
369	echo "FAIL: flow offload for ns1/ns2 with NAT and pmtu discovery" 1>&2
370	ip netns exec nsr1 nft list ruleset
371fi
372
373# Another test:
374# Add bridge interface br0 to Router1, with NAT enabled.
375ip -net nsr1 link add name br0 type bridge
376ip -net nsr1 addr flush dev veth0
377ip -net nsr1 link set up dev veth0
378ip -net nsr1 link set veth0 master br0
379ip -net nsr1 addr add 10.0.1.1/24 dev br0
380ip -net nsr1 addr add dead:1::1/64 dev br0
381ip -net nsr1 link set up dev br0
382
383ip netns exec nsr1 sysctl net.ipv4.conf.br0.forwarding=1 > /dev/null
384
385# br0 with NAT enabled.
386ip netns exec nsr1 nft -f - <<EOF
387flush table ip nat
388table ip nat {
389   chain prerouting {
390      type nat hook prerouting priority 0; policy accept;
391      meta iif "br0" ip daddr 10.6.6.6 tcp dport 1666 counter dnat ip to 10.0.2.99:12345
392   }
393
394   chain postrouting {
395      type nat hook postrouting priority 0; policy accept;
396      meta oifname "veth1" counter masquerade
397   }
398}
399EOF
400
401if test_tcp_forwarding_nat ns1 ns2; then
402	echo "PASS: flow offloaded for ns1/ns2 with bridge NAT"
403else
404	echo "FAIL: flow offload for ns1/ns2 with bridge NAT" 1>&2
405	ip netns exec nsr1 nft list ruleset
406	ret=1
407fi
408
409# Another test:
410# Add bridge interface br0 to Router1, with NAT and VLAN.
411ip -net nsr1 link set veth0 nomaster
412ip -net nsr1 link set down dev veth0
413ip -net nsr1 link add link veth0 name veth0.10 type vlan id 10
414ip -net nsr1 link set up dev veth0
415ip -net nsr1 link set up dev veth0.10
416ip -net nsr1 link set veth0.10 master br0
417
418ip -net ns1 addr flush dev eth0
419ip -net ns1 link add link eth0 name eth0.10 type vlan id 10
420ip -net ns1 link set eth0 up
421ip -net ns1 link set eth0.10 up
422ip -net ns1 addr add 10.0.1.99/24 dev eth0.10
423ip -net ns1 route add default via 10.0.1.1
424ip -net ns1 addr add dead:1::99/64 dev eth0.10
425
426if test_tcp_forwarding_nat ns1 ns2; then
427	echo "PASS: flow offloaded for ns1/ns2 with bridge NAT and VLAN"
428else
429	echo "FAIL: flow offload for ns1/ns2 with bridge NAT and VLAN" 1>&2
430	ip netns exec nsr1 nft list ruleset
431	ret=1
432fi
433
434# restore test topology (remove bridge and VLAN)
435ip -net nsr1 link set veth0 nomaster
436ip -net nsr1 link set veth0 down
437ip -net nsr1 link set veth0.10 down
438ip -net nsr1 link delete veth0.10 type vlan
439ip -net nsr1 link delete br0 type bridge
440ip -net ns1 addr flush dev eth0.10
441ip -net ns1 link set eth0.10 down
442ip -net ns1 link set eth0 down
443ip -net ns1 link delete eth0.10 type vlan
444
445# restore address in ns1 and nsr1
446ip -net ns1 link set eth0 up
447ip -net ns1 addr add 10.0.1.99/24 dev eth0
448ip -net ns1 route add default via 10.0.1.1
449ip -net ns1 addr add dead:1::99/64 dev eth0
450ip -net ns1 route add default via dead:1::1
451ip -net nsr1 addr add 10.0.1.1/24 dev veth0
452ip -net nsr1 addr add dead:1::1/64 dev veth0
453ip -net nsr1 link set up dev veth0
454
455KEY_SHA="0x"$(ps -xaf | sha1sum | cut -d " " -f 1)
456KEY_AES="0x"$(ps -xaf | md5sum | cut -d " " -f 1)
457SPI1=$RANDOM
458SPI2=$RANDOM
459
460if [ $SPI1 -eq $SPI2 ]; then
461	SPI2=$((SPI2+1))
462fi
463
464do_esp() {
465    local ns=$1
466    local me=$2
467    local remote=$3
468    local lnet=$4
469    local rnet=$5
470    local spi_out=$6
471    local spi_in=$7
472
473    ip -net $ns xfrm state add src $remote dst $me proto esp spi $spi_in  enc aes $KEY_AES  auth sha1 $KEY_SHA mode tunnel sel src $rnet dst $lnet
474    ip -net $ns xfrm state add src $me  dst $remote proto esp spi $spi_out enc aes $KEY_AES auth sha1 $KEY_SHA mode tunnel sel src $lnet dst $rnet
475
476    # to encrypt packets as they go out (includes forwarded packets that need encapsulation)
477    ip -net $ns xfrm policy add src $lnet dst $rnet dir out tmpl src $me dst $remote proto esp mode tunnel priority 1 action allow
478    # to fwd decrypted packets after esp processing:
479    ip -net $ns xfrm policy add src $rnet dst $lnet dir fwd tmpl src $remote dst $me proto esp mode tunnel priority 1 action allow
480
481}
482
483do_esp nsr1 192.168.10.1 192.168.10.2 10.0.1.0/24 10.0.2.0/24 $SPI1 $SPI2
484
485do_esp nsr2 192.168.10.2 192.168.10.1 10.0.2.0/24 10.0.1.0/24 $SPI2 $SPI1
486
487ip netns exec nsr1 nft delete table ip nat
488
489# restore default routes
490ip -net ns2 route del 192.168.10.1 via 10.0.2.1
491ip -net ns2 route add default via 10.0.2.1
492ip -net ns2 route add default via dead:2::1
493
494if test_tcp_forwarding ns1 ns2; then
495	echo "PASS: ipsec tunnel mode for ns1/ns2"
496else
497	echo "FAIL: ipsec tunnel mode for ns1/ns2"
498	ip netns exec nsr1 nft list ruleset 1>&2
499	ip netns exec nsr1 cat /proc/net/xfrm_stat 1>&2
500fi
501
502exit $ret
503