diff mbox series

[net-next,5/5] selftests: forwarding: Add test for minimum and maximum MTU

Message ID 89de8be8989db7a97f3b39e3c9da695673e78d2e.1718275854.git.petrm@nvidia.com (mailing list archive)
State Accepted
Commit 4be3dcc9bf04d0957235b45ba18983f1f751a3a1
Headers show
Series None | expand

Commit Message

Petr Machata June 13, 2024, 2:07 p.m. UTC
From: Amit Cohen <amcohen@nvidia.com>

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: Amit Cohen <amcohen@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
---

Cc: Shuah Khan <shuah@kernel.org>
Cc: linux-kselftest@vger.kernel.org

 .../testing/selftests/net/forwarding/Makefile |   1 +
 .../selftests/net/forwarding/min_max_mtu.sh   | 283 ++++++++++++++++++
 2 files changed, 284 insertions(+)
 create mode 100755 tools/testing/selftests/net/forwarding/min_max_mtu.sh
diff mbox series

Patch

diff --git a/tools/testing/selftests/net/forwarding/Makefile b/tools/testing/selftests/net/forwarding/Makefile
index 99576d7ecbf6..224346426ef2 100644
--- a/tools/testing/selftests/net/forwarding/Makefile
+++ b/tools/testing/selftests/net/forwarding/Makefile
@@ -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 \
diff --git a/tools/testing/selftests/net/forwarding/min_max_mtu.sh b/tools/testing/selftests/net/forwarding/min_max_mtu.sh
new file mode 100755
index 000000000000..97bb8b221bed
--- /dev/null
+++ b/tools/testing/selftests/net/forwarding/min_max_mtu.sh
@@ -0,0 +1,283 @@ 
+#!/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