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Commit b3cc4f8a authored by Paolo Abeni's avatar Paolo Abeni Committed by David S. Miller
Browse files

selftests: pmtu: add explicit tests for PMTU exceptions cleanup 



Add a couple of new tests, explicitly checking that the kernel
timely releases PMTU exceptions on related device removal.
This is mostly a regression test vs the issue fixed by
commit f5b51fe8 ("ipv6: route: purge exception on removal")

Only 2 new test cases have been added, instead of extending all
the existing ones, because the reproducer requires executing
several commands and would slow down too much the tests otherwise.

v2 -> v3:
 - more cleanup, still from Stefano

v1 -> v2:
 - several script cleanups, as suggested by Stefano

Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
Reviewed-by: default avatarDavid Ahern <dsahern@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 651eb32e

tools/testing/selftests/net/pmtu.sh

+67 −1
Original line number Diff line number Diff line
@@ -103,6 +103,15 @@ 
#	and check that configured MTU is used on link creation and changes, and

#	that MTU is properly calculated instead when MTU is not configured from

#	userspace

#

# - cleanup_ipv4_exception

#	Similar to pmtu_ipv4_vxlan4_exception, but explicitly generate PMTU

#	exceptions on multiple CPUs and check that the veth device tear-down

# 	happens in a timely manner

#

# - cleanup_ipv6_exception

#	Same as above, but use IPv6 transport from A to B





# Kselftest framework requirement - SKIP code is 4.

ksft_skip=4
@@ -135,7 +144,9 @@ tests=" 
	pmtu_vti6_default_mtu		vti6: default MTU assignment

	pmtu_vti4_link_add_mtu		vti4: MTU setting on link creation

	pmtu_vti6_link_add_mtu		vti6: MTU setting on link creation

	pmtu_vti6_link_change_mtu	vti6: MTU changes on link changes"

	pmtu_vti6_link_change_mtu	vti6: MTU changes on link changes

	cleanup_ipv4_exception		ipv4: cleanup of cached exceptions

	cleanup_ipv6_exception		ipv6: cleanup of cached exceptions"



NS_A="ns-$(mktemp -u XXXXXX)"

NS_B="ns-$(mktemp -u XXXXXX)"
@@ -1006,6 +1017,61 @@ test_pmtu_vti6_link_change_mtu() { 
	return ${fail}

}



check_command() {

	cmd=${1}



	if ! which ${cmd} > /dev/null 2>&1; then

		err "  missing required command: '${cmd}'"

		return 1

	fi

	return 0

}



test_cleanup_vxlanX_exception() {

	outer="${1}"

	encap="vxlan"

	ll_mtu=4000



	check_command taskset || return 2

	cpu_list=$(grep -m 2 processor /proc/cpuinfo | cut -d ' ' -f 2)



	setup namespaces routing ${encap}${outer} || return 2

	trace "${ns_a}" ${encap}_a   "${ns_b}"  ${encap}_b \

	      "${ns_a}" veth_A-R1    "${ns_r1}" veth_R1-A \

	      "${ns_b}" veth_B-R1    "${ns_r1}" veth_R1-B



	# Create route exception by exceeding link layer MTU

	mtu "${ns_a}"  veth_A-R1 $((${ll_mtu} + 1000))

	mtu "${ns_r1}" veth_R1-A $((${ll_mtu} + 1000))

	mtu "${ns_b}"  veth_B-R1 ${ll_mtu}

	mtu "${ns_r1}" veth_R1-B ${ll_mtu}



	mtu "${ns_a}" ${encap}_a $((${ll_mtu} + 1000))

	mtu "${ns_b}" ${encap}_b $((${ll_mtu} + 1000))



	# Fill exception cache for multiple CPUs (2)

	# we can always use inner IPv4 for that

	for cpu in ${cpu_list}; do

		taskset --cpu-list ${cpu} ${ns_a} ping -q -M want -i 0.1 -w 1 -s $((${ll_mtu} + 500)) ${tunnel4_b_addr} > /dev/null

	done



	${ns_a} ip link del dev veth_A-R1 &

	iplink_pid=$!

	sleep 1

	if [ "$(cat /proc/${iplink_pid}/cmdline 2>/dev/null | tr -d '\0')" = "iplinkdeldevveth_A-R1" ]; then

		err "  can't delete veth device in a timely manner, PMTU dst likely leaked"

		return 1

	fi

}



test_cleanup_ipv6_exception() {

	test_cleanup_vxlanX_exception 6

}



test_cleanup_ipv4_exception() {

	test_cleanup_vxlanX_exception 4

}



usage() {

	echo

	echo "$0 [OPTIONS] [TEST]..."