Commit 3ed61b89 authored by Justin Iurman's avatar Justin Iurman Committed by Paolo Abeni
Browse files

selftests: net: test for lwtunnel dst ref loops 



As recently specified by commit 0ea09cbf ("docs: netdev: add a note
on selftest posting") in net-next, the selftest is therefore shipped in
this series. However, this selftest does not really test this series. It
needs this series to avoid crashing the kernel. What it really tests,
thanks to kmemleak, is what was fixed by the following commits:
- commit c71a1929 ("net: ipv6: fix dst refleaks in rpl, seg6 and
ioam6 lwtunnels")
- commit 92191dd1 ("net: ipv6: fix dst ref loops in rpl, seg6 and
ioam6 lwtunnels")
- commit c64a0727 ("net: ipv6: fix dst ref loop on input in seg6
lwt")
- commit 13e55fba ("net: ipv6: fix dst ref loop on input in rpl
lwt")
- commit 0e7633d7 ("net: ipv6: fix dst ref loop in ila lwtunnel")
- commit 5da15a9c ("net: ipv6: fix missing dst ref drop in ila
lwtunnel")

Signed-off-by: default avatarJustin Iurman <justin.iurman@uliege.be>
Link: https://patch.msgid.link/20250314120048.12569-4-justin.iurman@uliege.be


Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
parent 3e7a60b3

tools/testing/selftests/net/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -101,6 +101,7 @@ TEST_PROGS += vlan_bridge_binding.sh 
TEST_PROGS += bpf_offload.py

TEST_PROGS += ipv6_route_update_soft_lockup.sh

TEST_PROGS += busy_poll_test.sh

TEST_PROGS += lwt_dst_cache_ref_loop.sh



# YNL files, must be before "include ..lib.mk"

YNL_GEN_FILES := busy_poller netlink-dumps

tools/testing/selftests/net/config

+2 −0
Original line number Diff line number Diff line
@@ -107,3 +107,5 @@ CONFIG_XFRM_INTERFACE=m 
CONFIG_XFRM_USER=m

CONFIG_IP_NF_MATCH_RPFILTER=m

CONFIG_IP6_NF_MATCH_RPFILTER=m

CONFIG_IPV6_ILA=m

CONFIG_IPV6_RPL_LWTUNNEL=y

tools/testing/selftests/net/lwt_dst_cache_ref_loop.sh

0 → 100755
+246 −0
Original line number Diff line number Diff line 
#!/bin/bash

# SPDX-License-Identifier: GPL-2.0+

#

# Author: Justin Iurman <justin.iurman@uliege.be>

#

# WARNING

# -------

# This is just a dummy script that triggers encap cases with possible dst cache

# reference loops in affected lwt users (see list below). Some cases are

# pathological configurations for simplicity, others are valid. Overall, we

# don't want this issue to happen, no matter what. In order to catch any

# reference loops, kmemleak MUST be used. The results alone are always blindly

# successful, don't rely on them. Note that the following tests may crash the

# kernel if the fix to prevent lwtunnel_{input|output|xmit}() reentry loops is

# not present.

#

# Affected lwt users so far (please update accordingly if needed):

#  - ila_lwt (output only)

#  - ioam6_iptunnel (output only)

#  - rpl_iptunnel (both input and output)

#  - seg6_iptunnel (both input and output)



source lib.sh



check_compatibility()

{

	setup_ns tmp_node &>/dev/null

	if [ $? != 0 ]; then

		echo "SKIP: Cannot create netns."

		exit $ksft_skip

	fi



	ip link add name veth0 netns $tmp_node type veth \

		peer name veth1 netns $tmp_node &>/dev/null

	local ret=$?



	ip -netns $tmp_node link set veth0 up &>/dev/null

	ret=$((ret + $?))



	ip -netns $tmp_node link set veth1 up &>/dev/null

	ret=$((ret + $?))



	if [ $ret != 0 ]; then

		echo "SKIP: Cannot configure links."

		cleanup_ns $tmp_node

		exit $ksft_skip

	fi



	lsmod 2>/dev/null | grep -q "ila"

	ila_lsmod=$?

	[ $ila_lsmod != 0 ] && modprobe ila &>/dev/null



	ip -netns $tmp_node route add 2001:db8:1::/64 \

		encap ila 1:2:3:4 csum-mode no-action ident-type luid \

			hook-type output \

		dev veth0 &>/dev/null



	ip -netns $tmp_node route add 2001:db8:2::/64 \

		encap ioam6 trace prealloc type 0x800000 ns 0 size 4 \

		dev veth0 &>/dev/null



	ip -netns $tmp_node route add 2001:db8:3::/64 \

		encap rpl segs 2001:db8:3::1 dev veth0 &>/dev/null



	ip -netns $tmp_node route add 2001:db8:4::/64 \

		encap seg6 mode inline segs 2001:db8:4::1 dev veth0 &>/dev/null



	ip -netns $tmp_node -6 route 2>/dev/null | grep -q "encap ila"

	skip_ila=$?



	ip -netns $tmp_node -6 route 2>/dev/null | grep -q "encap ioam6"

	skip_ioam6=$?



	ip -netns $tmp_node -6 route 2>/dev/null | grep -q "encap rpl"

	skip_rpl=$?



	ip -netns $tmp_node -6 route 2>/dev/null | grep -q "encap seg6"

	skip_seg6=$?



	cleanup_ns $tmp_node

}



setup()

{

	setup_ns alpha beta gamma &>/dev/null



	ip link add name veth-alpha netns $alpha type veth \

		peer name veth-betaL netns $beta &>/dev/null



	ip link add name veth-betaR netns $beta type veth \

		peer name veth-gamma netns $gamma &>/dev/null



	ip -netns $alpha link set veth-alpha name veth0 &>/dev/null

	ip -netns $beta link set veth-betaL name veth0 &>/dev/null

	ip -netns $beta link set veth-betaR name veth1 &>/dev/null

	ip -netns $gamma link set veth-gamma name veth0 &>/dev/null



	ip -netns $alpha addr add 2001:db8:1::2/64 dev veth0 &>/dev/null

	ip -netns $alpha link set veth0 up &>/dev/null

	ip -netns $alpha link set lo up &>/dev/null

	ip -netns $alpha route add 2001:db8:2::/64 \

		via 2001:db8:1::1 dev veth0 &>/dev/null



	ip -netns $beta addr add 2001:db8:1::1/64 dev veth0 &>/dev/null

	ip -netns $beta addr add 2001:db8:2::1/64 dev veth1 &>/dev/null

	ip -netns $beta link set veth0 up &>/dev/null

	ip -netns $beta link set veth1 up &>/dev/null

	ip -netns $beta link set lo up &>/dev/null

	ip -netns $beta route del 2001:db8:2::/64

	ip -netns $beta route add 2001:db8:2::/64 dev veth1

	ip netns exec $beta \

		sysctl -wq net.ipv6.conf.all.forwarding=1 &>/dev/null



	ip -netns $gamma addr add 2001:db8:2::2/64 dev veth0 &>/dev/null

	ip -netns $gamma link set veth0 up &>/dev/null

	ip -netns $gamma link set lo up &>/dev/null

	ip -netns $gamma route add 2001:db8:1::/64 \

		via 2001:db8:2::1 dev veth0 &>/dev/null



	sleep 1



	ip netns exec $alpha ping6 -c 5 -W 1 2001:db8:2::2 &>/dev/null

	if [ $? != 0 ]; then

		echo "SKIP: Setup failed."

		exit $ksft_skip

	fi



	sleep 1

}



cleanup()

{

	cleanup_ns $alpha $beta $gamma

	[ $ila_lsmod != 0 ] && modprobe -r ila &>/dev/null

}



run_ila()

{

	if [ $skip_ila != 0 ]; then

		echo "SKIP: ila (output)"

		return

	fi



	ip -netns $beta route del 2001:db8:2::/64

	ip -netns $beta route add 2001:db8:2:0:0:0:0:2/128 \

		encap ila 2001:db8:2:0 csum-mode no-action ident-type luid \

			hook-type output \

		dev veth1 &>/dev/null

	sleep 1



	echo "TEST: ila (output)"

	ip netns exec $beta ping6 -c 2 -W 1 2001:db8:2::2 &>/dev/null

	sleep 1



	ip -netns $beta route del 2001:db8:2:0:0:0:0:2/128

	ip -netns $beta route add 2001:db8:2::/64 dev veth1

	sleep 1

}



run_ioam6()

{

	if [ $skip_ioam6 != 0 ]; then

		echo "SKIP: ioam6 (output)"

		return

	fi



	ip -netns $beta route change 2001:db8:2::/64 \

		encap ioam6 trace prealloc type 0x800000 ns 1 size 4 \

		dev veth1 &>/dev/null

	sleep 1



	echo "TEST: ioam6 (output)"

	ip netns exec $beta ping6 -c 2 -W 1 2001:db8:2::2 &>/dev/null

	sleep 1

}



run_rpl()

{

	if [ $skip_rpl != 0 ]; then

		echo "SKIP: rpl (input)"

		echo "SKIP: rpl (output)"

		return

	fi



	ip -netns $beta route change 2001:db8:2::/64 \

		encap rpl segs 2001:db8:2::2 \

		dev veth1 &>/dev/null

	sleep 1



	echo "TEST: rpl (input)"

	ip netns exec $alpha ping6 -c 2 -W 1 2001:db8:2::2 &>/dev/null

	sleep 1



	echo "TEST: rpl (output)"

	ip netns exec $beta ping6 -c 2 -W 1 2001:db8:2::2 &>/dev/null

	sleep 1

}



run_seg6()

{

	if [ $skip_seg6 != 0 ]; then

		echo "SKIP: seg6 (input)"

		echo "SKIP: seg6 (output)"

		return

	fi



	ip -netns $beta route change 2001:db8:2::/64 \

		encap seg6 mode inline segs 2001:db8:2::2 \

		dev veth1 &>/dev/null

	sleep 1



	echo "TEST: seg6 (input)"

	ip netns exec $alpha ping6 -c 2 -W 1 2001:db8:2::2 &>/dev/null

	sleep 1



	echo "TEST: seg6 (output)"

	ip netns exec $beta ping6 -c 2 -W 1 2001:db8:2::2 &>/dev/null

	sleep 1

}



run()

{

	run_ila

	run_ioam6

	run_rpl

	run_seg6

}



if [ "$(id -u)" -ne 0 ]; then

	echo "SKIP: Need root privileges."

	exit $ksft_skip

fi



if [ ! -x "$(command -v ip)" ]; then

	echo "SKIP: Could not run test without ip tool."

	exit $ksft_skip

fi



check_compatibility



trap cleanup EXIT



setup

run



exit $ksft_pass