Commit ee9615be authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'more-pmtu-selftests' 



Sabrina Dubroca says:

====================
selftests: add more PMTU tests

The current selftests for PMTU cover VTI tunnels, but there's nothing
about the generation and handling of PMTU exceptions by intermediate
routers. This series adds and improves existing helpers, then adds
IPv4 and IPv6 selftests with a setup involving an intermediate router.

Joint work with Stefano Brivio.
====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents 062f97a3 e44e428f

tools/testing/selftests/net/pmtu.sh

+227 −31
Original line number Diff line number Diff line
@@ -6,6 +6,26 @@ 
#

# Tests currently implemented:

#

# - pmtu_ipv4

#	Set up two namespaces, A and B, with two paths between them over routers

#	R1 and R2 (also implemented with namespaces), with different MTUs:

#

#	  segment a_r1    segment b_r1		a_r1: 2000

#	.--------------R1--------------.	a_r2: 1500

#	A                               B	a_r3: 2000

#	'--------------R2--------------'	a_r4: 1400

#	  segment a_r2    segment b_r2

#

#	Check that PMTU exceptions with the correct PMTU are created. Then

#	decrease and increase the MTU of the local link for one of the paths,

#	A to R1, checking that route exception PMTU changes accordingly over

#	this path. Also check that locked exceptions are created when an ICMP

#	message advertising a PMTU smaller than net.ipv4.route.min_pmtu is

#	received

#

# - pmtu_ipv6

#	Same as pmtu_ipv4, except for locked PMTU tests, using IPv6

#

# - pmtu_vti4_exception

#	Set up vti tunnel on top of veth, with xfrm states and policies, in two

#	namespaces with matching endpoints. Check that route exception is not
@@ -50,6 +70,8 @@ ksft_skip=4 
which ping6 > /dev/null 2>&1 && ping6=$(which ping6) || ping6=$(which ping)



tests="

	pmtu_ipv4_exception		ipv4: PMTU exceptions

	pmtu_ipv6_exception		ipv6: PMTU exceptions

	pmtu_vti6_exception		vti6: PMTU exceptions

	pmtu_vti4_exception		vti4: PMTU exceptions

	pmtu_vti4_default_mtu		vti4: default MTU assignment
@@ -60,8 +82,45 @@ tests=" 


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

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

NS_R1="ns-$(mktemp -u XXXXXX)"

NS_R2="ns-$(mktemp -u XXXXXX)"

ns_a="ip netns exec ${NS_A}"

ns_b="ip netns exec ${NS_B}"

ns_r1="ip netns exec ${NS_R1}"

ns_r2="ip netns exec ${NS_R2}"



# Addressing and routing for tests with routers: four network segments, with

# index SEGMENT between 1 and 4, a common prefix (PREFIX4 or PREFIX6) and an

# identifier ID, which is 1 for hosts (A and B), 2 for routers (R1 and R2).

# Addresses are:

# - IPv4: PREFIX4.SEGMENT.ID (/24)

# - IPv6: PREFIX6:SEGMENT::ID (/64)

prefix4="192.168"

prefix6="fd00"

a_r1=1

a_r2=2

b_r1=3

b_r2=4

#	ns	peer	segment

routing_addrs="

	A	R1	${a_r1}

	A	R2	${a_r2}

	B	R1	${b_r1}

	B	R2	${b_r2}

"

# Traffic from A to B goes through R1 by default, and through R2, if destined to

# B's address on the b_r2 segment.

# Traffic from B to A goes through R1.

#	ns	destination		gateway

routes="

	A	default			${prefix4}.${a_r1}.2

	A	${prefix4}.${b_r2}.1	${prefix4}.${a_r2}.2

	B	default			${prefix4}.${b_r1}.2



	A	default			${prefix6}:${a_r1}::2

	A	${prefix6}:${b_r2}::1	${prefix6}:${a_r2}::2

	B	default			${prefix6}:${b_r1}::2

"



veth4_a_addr="192.168.1.1"

veth4_b_addr="192.168.1.2"
@@ -94,9 +153,15 @@ err_flush() { 
	err_buf=

}



# Find the auto-generated name for this namespace

nsname() {

	eval echo \$NS_$1

}



setup_namespaces() {

	ip netns add ${NS_A} || return 1

	ip netns add ${NS_B}

	for n in ${NS_A} ${NS_B} ${NS_R1} ${NS_R2}; do

		ip netns add ${n} || return 1

	done

}



setup_veth() {
@@ -167,6 +232,49 @@ setup_xfrm6() { 
	setup_xfrm 6 ${veth6_a_addr} ${veth6_b_addr}

}



setup_routing() {

	for i in ${NS_R1} ${NS_R2}; do

		ip netns exec ${i} sysctl -q net/ipv4/ip_forward=1

		ip netns exec ${i} sysctl -q net/ipv6/conf/all/forwarding=1

	done



	for i in ${routing_addrs}; do

		[ "${ns}" = "" ]	&& ns="${i}"		&& continue

		[ "${peer}" = "" ]	&& peer="${i}"		&& continue

		[ "${segment}" = "" ]	&& segment="${i}"



		ns_name="$(nsname ${ns})"

		peer_name="$(nsname ${peer})"

		if="veth_${ns}-${peer}"

		ifpeer="veth_${peer}-${ns}"



		# Create veth links

		ip link add ${if} up netns ${ns_name} type veth peer name ${ifpeer} netns ${peer_name} || return 1

		ip -n ${peer_name} link set dev ${ifpeer} up



		# Add addresses

		ip -n ${ns_name}   addr add ${prefix4}.${segment}.1/24  dev ${if}

		ip -n ${ns_name}   addr add ${prefix6}:${segment}::1/64 dev ${if}



		ip -n ${peer_name} addr add ${prefix4}.${segment}.2/24  dev ${ifpeer}

		ip -n ${peer_name} addr add ${prefix6}:${segment}::2/64 dev ${ifpeer}



		ns=""; peer=""; segment=""

	done



	for i in ${routes}; do

		[ "${ns}" = "" ]	&& ns="${i}"		&& continue

		[ "${addr}" = "" ]	&& addr="${i}"		&& continue

		[ "${gw}" = "" ]	&& gw="${i}"



		ns_name="$(nsname ${ns})"



		ip -n ${ns_name} route add ${addr} via ${gw}



		ns=""; addr=""; gw=""

	done

}



setup() {

	[ "$(id -u)" -ne 0 ] && echo "  need to run as root" && return $ksft_skip
@@ -178,8 +286,9 @@ setup() { 


cleanup() {

	[ ${cleanup_done} -eq 1 ] && return

	ip netns del ${NS_A} 2> /dev/null

	ip netns del ${NS_B} 2> /dev/null

	for n in ${NS_A} ${NS_B} ${NS_R1} ${NS_R2}; do

		ip netns del ${n} 2> /dev/null

	done

	cleanup_done=1

}
@@ -196,7 +305,9 @@ mtu_parse() { 


	next=0

	for i in ${input}; do

		[ ${next} -eq 1 -a "${i}" = "lock" ] && next=2 && continue

		[ ${next} -eq 1 ] && echo "${i}" && return

		[ ${next} -eq 2 ] && echo "lock ${i}" && return

		[ "${i}" = "mtu" ] && next=1

	done

}
@@ -229,6 +340,109 @@ route_get_dst_pmtu_from_exception() { 
	mtu_parse "$(route_get_dst_exception "${ns_cmd}" ${dst})"

}



check_pmtu_value() {

	expected="${1}"

	value="${2}"

	event="${3}"



	[ "${expected}" = "any" ] && [ -n "${value}" ] && return 0

	[ "${value}" = "${expected}" ] && return 0

	[ -z "${value}" ] &&    err "  PMTU exception wasn't created after ${event}" && return 1

	[ -z "${expected}" ] && err "  PMTU exception shouldn't exist after ${event}" && return 1

	err "  found PMTU exception with incorrect MTU ${value}, expected ${expected}, after ${event}"

	return 1

}



test_pmtu_ipvX() {

	family=${1}



	setup namespaces routing || return 2



	if [ ${family} -eq 4 ]; then

		ping=ping

		dst1="${prefix4}.${b_r1}.1"

		dst2="${prefix4}.${b_r2}.1"

	else

		ping=${ping6}

		dst1="${prefix6}:${b_r1}::1"

		dst2="${prefix6}:${b_r2}::1"

	fi



	# Set up initial MTU values

	mtu "${ns_a}"  veth_A-R1 2000

	mtu "${ns_r1}" veth_R1-A 2000

	mtu "${ns_r1}" veth_R1-B 1400

	mtu "${ns_b}"  veth_B-R1 1400



	mtu "${ns_a}"  veth_A-R2 2000

	mtu "${ns_r2}" veth_R2-A 2000

	mtu "${ns_r2}" veth_R2-B 1500

	mtu "${ns_b}"  veth_B-R2 1500



	# Create route exceptions

	${ns_a} ${ping} -q -M want -i 0.1 -w 2 -s 1800 ${dst1} > /dev/null

	${ns_a} ${ping} -q -M want -i 0.1 -w 2 -s 1800 ${dst2} > /dev/null



	# Check that exceptions have been created with the correct PMTU

	pmtu_1="$(route_get_dst_pmtu_from_exception "${ns_a}" ${dst1})"

	check_pmtu_value "1400" "${pmtu_1}" "exceeding MTU" || return 1

	pmtu_2="$(route_get_dst_pmtu_from_exception "${ns_a}" ${dst2})"

	check_pmtu_value "1500" "${pmtu_2}" "exceeding MTU" || return 1



	# Decrease local MTU below PMTU, check for PMTU decrease in route exception

	mtu "${ns_a}"  veth_A-R1 1300

	mtu "${ns_r1}" veth_R1-A 1300

	pmtu_1="$(route_get_dst_pmtu_from_exception "${ns_a}" ${dst1})"

	check_pmtu_value "1300" "${pmtu_1}" "decreasing local MTU" || return 1

	# Second exception shouldn't be modified

	pmtu_2="$(route_get_dst_pmtu_from_exception "${ns_a}" ${dst2})"

	check_pmtu_value "1500" "${pmtu_2}" "changing local MTU on a link not on this path" || return 1



	# Increase MTU, check for PMTU increase in route exception

	mtu "${ns_a}"  veth_A-R1 1700

	mtu "${ns_r1}" veth_R1-A 1700

	pmtu_1="$(route_get_dst_pmtu_from_exception "${ns_a}" ${dst1})"

	check_pmtu_value "1700" "${pmtu_1}" "increasing local MTU" || return 1

	# Second exception shouldn't be modified

	pmtu_2="$(route_get_dst_pmtu_from_exception "${ns_a}" ${dst2})"

	check_pmtu_value "1500" "${pmtu_2}" "changing local MTU on a link not on this path" || return 1



	# Skip PMTU locking tests for IPv6

	[ $family -eq 6 ] && return 0



	# Decrease remote MTU on path via R2, get new exception

	mtu "${ns_r2}" veth_R2-B 400

	mtu "${ns_b}"  veth_B-R2 400

	${ns_a} ${ping} -q -M want -i 0.1 -w 2 -s 1400 ${dst2} > /dev/null

	pmtu_2="$(route_get_dst_pmtu_from_exception "${ns_a}" ${dst2})"

	check_pmtu_value "lock 552" "${pmtu_2}" "exceeding MTU, with MTU < min_pmtu" || return 1



	# Decrease local MTU below PMTU

	mtu "${ns_a}"  veth_A-R2 500

	mtu "${ns_r2}" veth_R2-A 500

	pmtu_2="$(route_get_dst_pmtu_from_exception "${ns_a}" ${dst2})"

	check_pmtu_value "500" "${pmtu_2}" "decreasing local MTU" || return 1



	# Increase local MTU

	mtu "${ns_a}"  veth_A-R2 1500

	mtu "${ns_r2}" veth_R2-A 1500

	pmtu_2="$(route_get_dst_pmtu_from_exception "${ns_a}" ${dst2})"

	check_pmtu_value "1500" "${pmtu_2}" "increasing local MTU" || return 1



	# Get new exception

	${ns_a} ${ping} -q -M want -i 0.1 -w 2 -s 1400 ${dst2} > /dev/null

	pmtu_2="$(route_get_dst_pmtu_from_exception "${ns_a}" ${dst2})"

	check_pmtu_value "lock 552" "${pmtu_2}" "exceeding MTU, with MTU < min_pmtu" || return 1

}



test_pmtu_ipv4_exception() {

	test_pmtu_ipvX 4

}



test_pmtu_ipv6_exception() {

	test_pmtu_ipvX 6

}



test_pmtu_vti4_exception() {

	setup namespaces veth vti4 xfrm4 || return 2
@@ -248,24 +462,13 @@ test_pmtu_vti4_exception() { 
	# exception is created

	${ns_a} ping -q -M want -i 0.1 -w 2 -s ${ping_payload} ${vti4_b_addr} > /dev/null

	pmtu="$(route_get_dst_pmtu_from_exception "${ns_a}" ${vti4_b_addr})"

	if [ "${pmtu}" != "" ]; then

		err "  unexpected exception created with PMTU ${pmtu} for IP payload length ${esp_payload_rfc4106}"

		return 1

	fi

	check_pmtu_value "" "${pmtu}" "sending packet smaller than PMTU (IP payload length ${esp_payload_rfc4106})" || return 1



	# Now exceed link layer MTU by one byte, check that exception is created

	# with the right PMTU value

	${ns_a} ping -q -M want -i 0.1 -w 2 -s $((ping_payload + 1)) ${vti4_b_addr} > /dev/null

	pmtu="$(route_get_dst_pmtu_from_exception "${ns_a}" ${vti4_b_addr})"

	if [ "${pmtu}" = "" ]; then

		err "  exception not created for IP payload length $((esp_payload_rfc4106 + 1))"

		return 1

	fi



	# ...with the right PMTU value

	if [ ${pmtu} -ne ${esp_payload_rfc4106} ]; then

		err "  wrong PMTU ${pmtu} in exception, expected: ${esp_payload_rfc4106}"

		return 1

	fi

	check_pmtu_value "${esp_payload_rfc4106}" "${pmtu}" "exceeding PMTU (IP payload length $((esp_payload_rfc4106 + 1)))"

}



test_pmtu_vti6_exception() {
@@ -280,25 +483,18 @@ test_pmtu_vti6_exception() { 
	${ns_a} ${ping6} -q -i 0.1 -w 2 -s 60000 ${vti6_b_addr} > /dev/null



	# Check that exception was created

	if [ "$(route_get_dst_pmtu_from_exception "${ns_a}" ${vti6_b_addr})" = "" ]; then

		err "  tunnel exceeding link layer MTU didn't create route exception"

		return 1

	fi

	pmtu="$(route_get_dst_pmtu_from_exception "${ns_a}" ${vti6_b_addr})"

	check_pmtu_value any "${pmtu}" "creating tunnel exceeding link layer MTU" || return 1



	# Decrease tunnel MTU, check for PMTU decrease in route exception

	mtu "${ns_a}" vti6_a 3000



	if [ "$(route_get_dst_pmtu_from_exception "${ns_a}" ${vti6_b_addr})" -ne 3000 ]; then

		err "  decreasing tunnel MTU didn't decrease route exception PMTU"

		fail=1

	fi

	pmtu="$(route_get_dst_pmtu_from_exception "${ns_a}" ${vti6_b_addr})"

	check_pmtu_value "3000" "${pmtu}" "decreasing tunnel MTU" || fail=1



	# Increase tunnel MTU, check for PMTU increase in route exception

	mtu "${ns_a}" vti6_a 9000

	if [ "$(route_get_dst_pmtu_from_exception "${ns_a}" ${vti6_b_addr})" -ne 9000 ]; then

		err "  increasing tunnel MTU didn't increase route exception PMTU"

		fail=1

	fi

	pmtu="$(route_get_dst_pmtu_from_exception "${ns_a}" ${vti6_b_addr})"

	check_pmtu_value "9000" "${pmtu}" "increasing tunnel MTU" || fail=1



	return ${fail}

}

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