selftests: net: test for lwtunnel dst ref loops

As recently specified by commit 0ea09cbf83 ("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 c71a192976 ("net: ipv6: fix dst refleaks in rpl, seg6 and
ioam6 lwtunnels")
- commit 92191dd107 ("net: ipv6: fix dst ref loops in rpl, seg6 and
ioam6 lwtunnels")
- commit c64a0727f9 ("net: ipv6: fix dst ref loop on input in seg6
lwt")
- commit 13e55fbaec ("net: ipv6: fix dst ref loop on input in rpl
lwt")
- commit 0e7633d7b9 ("net: ipv6: fix dst ref loop in ila lwtunnel")
- commit 5da15a9c11 ("net: ipv6: fix missing dst ref drop in ila
lwtunnel")

Signed-off-by: Justin Iurman <justin.iurman@uliege.be>
Link: https://patch.msgid.link/20250314120048.12569-4-justin.iurman@uliege.be
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
This commit is contained in:
Justin Iurman 2025-03-14 13:00:48 +01:00 committed by Paolo Abeni
parent 3e7a60b368
commit 3ed61b8938
3 changed files with 249 additions and 0 deletions

View file

@ -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

View file

@ -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

View file

@ -0,0 +1,246 @@
#!/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