Commit 4be3dcc9 authored by Amit Cohen's avatar Amit Cohen Committed by Jakub Kicinski
Browse files

selftests: forwarding: Add test for minimum and maximum MTU 



Add cases to check minimum and maximum MTU which are exposed via
"ip -d link show". Test configuration and traffic. Use VLAN devices as
usually VLAN header (4 bytes) is not included in the MTU, and drivers
should configure hardware correctly to send maximum MTU payload size
in VLAN tagged packets.

$ ./min_max_mtu.sh
TEST: ping						[ OK ]
TEST: ping6						[ OK ]
TEST: Test maximum MTU configuration			[ OK ]
TEST: Test traffic, packet size is maximum MTU		[ OK ]
TEST: Test minimum MTU configuration			[ OK ]
TEST: Test traffic, packet size is minimum MTU		[ OK ]

Signed-off-by: default avatarAmit Cohen <amcohen@nvidia.com>
Reviewed-by: default avatarPetr Machata <petrm@nvidia.com>
Signed-off-by: default avatarPetr Machata <petrm@nvidia.com>
Link: https://lore.kernel.org/r/89de8be8989db7a97f3b39e3c9da695673e78d2e.1718275854.git.petrm@nvidia.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 3e785654

tools/testing/selftests/net/forwarding/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -39,6 +39,7 @@ TEST_PROGS = bridge_fdb_learning_limit.sh \ 
	ipip_hier_gre.sh \

	lib_sh_test.sh \

	local_termination.sh \

	min_max_mtu.sh \

	mirror_gre_bound.sh \

	mirror_gre_bridge_1d.sh \

	mirror_gre_bridge_1d_vlan.sh \

tools/testing/selftests/net/forwarding/min_max_mtu.sh

0 → 100755
+283 −0
Original line number Diff line number Diff line 
#!/bin/bash

# SPDX-License-Identifier: GPL-2.0



# +--------------------+

# | H1                 |

# |                    |

# |           $h1.10 + |

# |     192.0.2.2/24 | |

# | 2001:db8:1::2/64 | |

# |                  | |

# |              $h1 + |

# |                  | |

# +------------------|-+

#                    |

# +------------------|-+

# | SW               | |

# |            $swp1 + |

# |                  | |

# |         $swp1.10 + |

# |     192.0.2.1/24   |

# | 2001:db8:1::1/64   |

# |                    |

# +--------------------+



ALL_TESTS="

	ping_ipv4

	ping_ipv6

	max_mtu_config_test

	max_mtu_traffic_test

	min_mtu_config_test

	min_mtu_traffic_test

"



NUM_NETIFS=2

source lib.sh



h1_create()

{

	simple_if_init $h1

	vlan_create $h1 10 v$h1 192.0.2.2/24 2001:db8:1::2/64

}



h1_destroy()

{

	vlan_destroy $h1 10 192.0.2.2/24 2001:db8:1::2/64

	simple_if_fini $h1

}



switch_create()

{

	ip li set dev $swp1 up

	vlan_create $swp1 10 "" 192.0.2.1/24 2001:db8:1::1/64

}



switch_destroy()

{

	ip li set dev $swp1 down

	vlan_destroy $swp1 10

}



setup_prepare()

{

	h1=${NETIFS[p1]}

	swp1=${NETIFS[p2]}



	vrf_prepare



	h1_create



	switch_create



	forwarding_enable

}



cleanup()

{

	pre_cleanup



	forwarding_restore



	switch_destroy



	h1_destroy



	vrf_cleanup

}



ping_ipv4()

{

	ping_test $h1.10 192.0.2.1

}



ping_ipv6()

{

	ping6_test $h1.10 2001:db8:1::1

}



min_max_mtu_get_if()

{

	local dev=$1; shift

	local min_max=$1; shift



	ip -d -j link show $dev | jq ".[].$min_max"

}



ensure_compatible_min_max_mtu()

{

	local min_max=$1; shift



	local mtu=$(min_max_mtu_get_if ${NETIFS[p1]} $min_max)

	local i



	for ((i = 2; i <= NUM_NETIFS; ++i)); do

		local current_mtu=$(min_max_mtu_get_if ${NETIFS[p$i]} $min_max)



		if [ $current_mtu -ne $mtu ]; then

			return 1

		fi

	done

}



mtu_set_if()

{

	local dev=$1; shift

	local mtu=$1; shift

	local should_fail=${1:-0}; shift



	mtu_set $dev $mtu 2>/dev/null

	check_err_fail $should_fail $? "Set MTU $mtu for $dev"

}



mtu_set_all_if()

{

	local mtu=$1; shift

	local i



	for ((i = 1; i <= NUM_NETIFS; ++i)); do

		mtu_set_if ${NETIFS[p$i]} $mtu

		mtu_set_if ${NETIFS[p$i]}.10 $mtu

	done

}



mtu_restore_all_if()

{

	local i



	for ((i = 1; i <= NUM_NETIFS; ++i)); do

		mtu_restore ${NETIFS[p$i]}.10

		mtu_restore ${NETIFS[p$i]}

	done

}



mtu_test_ping4()

{

	local mtu=$1; shift

	local should_fail=$1; shift



	# Ping adds 8 bytes for ICMP header and 20 bytes for IP header

	local ping_headers_len=$((20 + 8))

	local pkt_size=$((mtu - ping_headers_len))



	ping_do $h1.10 192.0.2.1 "-s $pkt_size -M do"

	check_err_fail $should_fail $? "Ping, packet size: $pkt_size"

}



mtu_test_ping6()

{

	local mtu=$1; shift

	local should_fail=$1; shift



	# Ping adds 8 bytes for ICMP header and 40 bytes for IPv6 header

	local ping6_headers_len=$((40 + 8))

	local pkt_size=$((mtu - ping6_headers_len))



	ping6_do $h1.10 2001:db8:1::1 "-s $pkt_size -M do"

	check_err_fail $should_fail $? "Ping6, packet size: $pkt_size"

}



max_mtu_config_test()

{

	local i



	RET=0



	for ((i = 1; i <= NUM_NETIFS; ++i)); do

		local dev=${NETIFS[p$i]}

		local max_mtu=$(min_max_mtu_get_if $dev "max_mtu")

		local should_fail



		should_fail=0

		mtu_set_if $dev $max_mtu $should_fail

		mtu_restore $dev



		should_fail=1

		mtu_set_if $dev $((max_mtu + 1)) $should_fail

		mtu_restore $dev

	done



	log_test "Test maximum MTU configuration"

}



max_mtu_traffic_test()

{

	local should_fail

	local max_mtu



	RET=0



	if ! ensure_compatible_min_max_mtu "max_mtu"; then

		log_test_xfail "Topology has incompatible maximum MTU values"

		return

	fi



	max_mtu=$(min_max_mtu_get_if ${NETIFS[p1]} "max_mtu")



	should_fail=0

	mtu_set_all_if $max_mtu

	mtu_test_ping4 $max_mtu $should_fail

	mtu_test_ping6 $max_mtu $should_fail

	mtu_restore_all_if



	should_fail=1

	mtu_set_all_if $((max_mtu - 1))

	mtu_test_ping4 $max_mtu $should_fail

	mtu_test_ping6 $max_mtu $should_fail

	mtu_restore_all_if



	log_test "Test traffic, packet size is maximum MTU"

}



min_mtu_config_test()

{

	local i



	RET=0



	for ((i = 1; i <= NUM_NETIFS; ++i)); do

		local dev=${NETIFS[p$i]}

		local min_mtu=$(min_max_mtu_get_if $dev "min_mtu")

		local should_fail



		should_fail=0

		mtu_set_if $dev $min_mtu $should_fail

		mtu_restore $dev



		should_fail=1

		mtu_set_if $dev $((min_mtu - 1)) $should_fail

		mtu_restore $dev

	done



	log_test "Test minimum MTU configuration"

}



min_mtu_traffic_test()

{

	local should_fail=0

	local min_mtu



	RET=0



	if ! ensure_compatible_min_max_mtu "min_mtu"; then

		log_test_xfail "Topology has incompatible minimum MTU values"

		return

	fi



	min_mtu=$(min_max_mtu_get_if ${NETIFS[p1]} "min_mtu")

	mtu_set_all_if $min_mtu

	mtu_test_ping4 $min_mtu $should_fail

	# Do not test minimum MTU with IPv6, as IPv6 requires higher MTU.



	mtu_restore_all_if



	log_test "Test traffic, packet size is minimum MTU"

}



trap cleanup EXIT



setup_prepare

setup_wait



tests_run



exit $EXIT_STATUS