tools/testing/selftests/net/bridge_stp_mode.sh - linux - Git at Google

 #!/bin/bash
 # SPDX-License-Identifier: GPL-2.0
 # shellcheck disable=SC2034,SC2154,SC2317,SC2329
 #
 # Test for bridge STP mode selection (IFLA_BR_STP_MODE).
 #
 # Verifies that:
 # - stp_mode defaults to auto on new bridges
 # - stp_mode can be toggled between user, kernel, and auto
 # - stp_mode change is rejected while STP is active (-EBUSY)
 # - stp_mode user in a netns yields userspace STP (stp_state=2)
 # - stp_mode kernel forces kernel STP (stp_state=1)
 # - stp_mode auto preserves traditional fallback to kernel STP
 # - stp_mode and stp_state can be set atomically in one message
 # - stp_mode persists across STP disable/enable cycles

 source lib.sh

 require_command jq

 ALL_TESTS="
 	test_default_auto
 	test_set_modes
 	test_reject_change_while_stp_active
 	test_idempotent_mode_while_stp_active
 	test_user_mode_in_netns
 	test_kernel_mode
 	test_auto_mode
 	test_atomic_mode_and_state
 	test_mode_persistence
 "

 bridge_info_get()
 {
 	ip -n "$NS1" -d -j link show "$1" | \
 		jq -r ".[0].linkinfo.info_data.$2"
 }

 check_stp_mode()
 {
 	local br=$1; shift
 	local expected=$1; shift
 	local msg=$1; shift
 	local val

 	val=$(bridge_info_get "$br" stp_mode)
 	[ "$val" = "$expected" ]
 	check_err $? "$msg: expected $expected, got $val"
 }

 check_stp_state()
 {
 	local br=$1; shift
 	local expected=$1; shift
 	local msg=$1; shift
 	local val

 	val=$(bridge_info_get "$br" stp_state)
 	[ "$val" = "$expected" ]
 	check_err $? "$msg: expected $expected, got $val"
 }

 # Create a bridge in NS1, bring it up, and defer its deletion.
 bridge_create()
 {
 	ip -n "$NS1" link add "$1" type bridge
 	ip -n "$NS1" link set "$1" up
 	defer ip -n "$NS1" link del "$1"
 }

 setup_prepare()
 {
 	setup_ns NS1
 }

 cleanup()
 {
 	defer_scopes_cleanup
 	cleanup_all_ns
 }

 # Check that stp_mode defaults to auto when creating a bridge.
 test_default_auto()
 {
 	RET=0

 	ip -n "$NS1" link add br-test type bridge
 	defer ip -n "$NS1" link del br-test

 	check_stp_mode br-test auto "stp_mode default"

 	log_test "stp_mode defaults to auto"
 }

 # Test setting stp_mode to user, kernel, and back to auto.
 test_set_modes()
 {
 	RET=0

 	ip -n "$NS1" link add br-test type bridge
 	defer ip -n "$NS1" link del br-test

 	ip -n "$NS1" link set dev br-test type bridge stp_mode user
 	check_err $? "Failed to set stp_mode to user"
 	check_stp_mode br-test user "after set user"

 	ip -n "$NS1" link set dev br-test type bridge stp_mode kernel
 	check_err $? "Failed to set stp_mode to kernel"
 	check_stp_mode br-test kernel "after set kernel"

 	ip -n "$NS1" link set dev br-test type bridge stp_mode auto
 	check_err $? "Failed to set stp_mode to auto"
 	check_stp_mode br-test auto "after set auto"

 	log_test "stp_mode set user/kernel/auto"
 }

 # Verify that stp_mode cannot be changed while STP is active.
 test_reject_change_while_stp_active()
 {
 	RET=0

 	bridge_create br-test

 	ip -n "$NS1" link set dev br-test type bridge stp_mode kernel
 	check_err $? "Failed to set stp_mode to kernel"

 	ip -n "$NS1" link set dev br-test type bridge stp_state 1
 	check_err $? "Failed to enable STP"

 	# Changing stp_mode while STP is active should fail.
 	ip -n "$NS1" link set dev br-test type bridge stp_mode auto 2>/dev/null
 	check_fail $? "Changing stp_mode should fail while STP is active"

 	check_stp_mode br-test kernel "mode unchanged after rejected change"

 	# Disable STP, then change should succeed.
 	ip -n "$NS1" link set dev br-test type bridge stp_state 0
 	check_err $? "Failed to disable STP"

 	ip -n "$NS1" link set dev br-test type bridge stp_mode auto
 	check_err $? "Changing stp_mode should succeed after STP is disabled"

 	log_test "reject stp_mode change while STP is active"
 }

 # Verify that re-setting the same stp_mode while STP is active succeeds.
 test_idempotent_mode_while_stp_active()
 {
 	RET=0

 	bridge_create br-test

 	ip -n "$NS1" link set dev br-test type bridge stp_mode user stp_state 1
 	check_err $? "Failed to enable STP with user mode"

 	# Re-setting the same mode while STP is active should succeed.
 	ip -n "$NS1" link set dev br-test type bridge stp_mode user
 	check_err $? "Idempotent stp_mode set should succeed while STP is active"

 	check_stp_state br-test 2 "stp_state after idempotent set"

 	# Changing mode while disabling STP in the same message should succeed.
 	ip -n "$NS1" link set dev br-test type bridge stp_mode auto stp_state 0
 	check_err $? "Mode change with simultaneous STP disable should succeed"

 	check_stp_mode br-test auto "mode changed after disable+change"
 	check_stp_state br-test 0 "stp_state after disable+change"

 	log_test "idempotent and simultaneous mode change while STP active"
 }

 # Test that stp_mode user in a non-init netns yields userspace STP
 # (stp_state == 2). This is the key use case: userspace STP without
 # needing /sbin/bridge-stp or being in init_net.
 test_user_mode_in_netns()
 {
 	RET=0

 	bridge_create br-test

 	ip -n "$NS1" link set dev br-test type bridge stp_mode user
 	check_err $? "Failed to set stp_mode to user"

 	ip -n "$NS1" link set dev br-test type bridge stp_state 1
 	check_err $? "Failed to enable STP"

 	check_stp_state br-test 2 "stp_state with user mode"

 	log_test "stp_mode user in netns yields userspace STP"
 }

 # Test that stp_mode kernel forces kernel STP (stp_state == 1)
 # regardless of whether /sbin/bridge-stp exists.
 test_kernel_mode()
 {
 	RET=0

 	bridge_create br-test

 	ip -n "$NS1" link set dev br-test type bridge stp_mode kernel
 	check_err $? "Failed to set stp_mode to kernel"

 	ip -n "$NS1" link set dev br-test type bridge stp_state 1
 	check_err $? "Failed to enable STP"

 	check_stp_state br-test 1 "stp_state with kernel mode"

 	log_test "stp_mode kernel forces kernel STP"
 }

 # Test that stp_mode auto preserves traditional behavior: in a netns
 # (non-init_net), bridge-stp is not called and STP falls back to
 # kernel mode (stp_state == 1).
 test_auto_mode()
 {
 	RET=0

 	bridge_create br-test

 	# Auto mode is the default; enable STP in a netns.
 	ip -n "$NS1" link set dev br-test type bridge stp_state 1
 	check_err $? "Failed to enable STP"

 	# In a netns with auto mode, bridge-stp is skipped (init_net only),
 	# so STP should fall back to kernel mode (stp_state == 1).
 	check_stp_state br-test 1 "stp_state with auto mode in netns"

 	log_test "stp_mode auto preserves traditional behavior"
 }

 # Test that stp_mode and stp_state can be set in a single netlink
 # message. This is the intended atomic usage pattern.
 test_atomic_mode_and_state()
 {
 	RET=0

 	bridge_create br-test

 	# Set both stp_mode and stp_state in one command.
 	ip -n "$NS1" link set dev br-test type bridge stp_mode user stp_state 1
 	check_err $? "Failed to set stp_mode user and stp_state 1 atomically"

 	check_stp_state br-test 2 "stp_state after atomic set"

 	log_test "atomic stp_mode user + stp_state 1 in single message"
 }

 # Test that stp_mode persists across STP disable/enable cycles.
 test_mode_persistence()
 {
 	RET=0

 	bridge_create br-test

 	# Set user mode and enable STP.
 	ip -n "$NS1" link set dev br-test type bridge stp_mode user
 	ip -n "$NS1" link set dev br-test type bridge stp_state 1
 	check_err $? "Failed to enable STP with user mode"

 	# Disable STP.
 	ip -n "$NS1" link set dev br-test type bridge stp_state 0
 	check_err $? "Failed to disable STP"

 	# Verify mode is still user.
 	check_stp_mode br-test user "stp_mode after STP disable"

 	# Re-enable STP -- should use user mode again.
 	ip -n "$NS1" link set dev br-test type bridge stp_state 1
 	check_err $? "Failed to re-enable STP"

 	check_stp_state br-test 2 "stp_state after re-enable"

 	log_test "stp_mode persists across STP disable/enable cycles"
 }

 # Check iproute2 support before setting up resources.
 if ! ip link add type bridge help 2>&1 | grep -q "stp_mode"; then
 	echo "SKIP: iproute2 too old, missing stp_mode support"
 	exit "$ksft_skip"
 fi

 trap cleanup EXIT

 setup_prepare
 tests_run

 exit "$EXIT_STATUS"
	#!/bin/bash
	# SPDX-License-Identifier: GPL-2.0
	# shellcheck disable=SC2034,SC2154,SC2317,SC2329
	#
	# Test for bridge STP mode selection (IFLA_BR_STP_MODE).
	#
	# Verifies that:
	# - stp_mode defaults to auto on new bridges
	# - stp_mode can be toggled between user, kernel, and auto
	# - stp_mode change is rejected while STP is active (-EBUSY)
	# - stp_mode user in a netns yields userspace STP (stp_state=2)
	# - stp_mode kernel forces kernel STP (stp_state=1)
	# - stp_mode auto preserves traditional fallback to kernel STP
	# - stp_mode and stp_state can be set atomically in one message
	# - stp_mode persists across STP disable/enable cycles

	source lib.sh

	require_command jq

	ALL_TESTS="
	test_default_auto
	test_set_modes
	test_reject_change_while_stp_active
	test_idempotent_mode_while_stp_active
	test_user_mode_in_netns
	test_kernel_mode
	test_auto_mode
	test_atomic_mode_and_state
	test_mode_persistence
	"

	bridge_info_get()
	{
	ip -n "$NS1" -d -j link show "$1" \| \
	jq -r ".[0].linkinfo.info_data.$2"
	}

	check_stp_mode()
	{
	local br=$1; shift
	local expected=$1; shift
	local msg=$1; shift
	local val

	val=$(bridge_info_get "$br" stp_mode)
	[ "$val" = "$expected" ]
	check_err $? "$msg: expected $expected, got $val"
	}

	check_stp_state()
	{
	local br=$1; shift
	local expected=$1; shift
	local msg=$1; shift
	local val

	val=$(bridge_info_get "$br" stp_state)
	[ "$val" = "$expected" ]
	check_err $? "$msg: expected $expected, got $val"
	}

	# Create a bridge in NS1, bring it up, and defer its deletion.
	bridge_create()
	{
	ip -n "$NS1" link add "$1" type bridge
	ip -n "$NS1" link set "$1" up
	defer ip -n "$NS1" link del "$1"
	}

	setup_prepare()
	{
	setup_ns NS1
	}

	cleanup()
	{
	defer_scopes_cleanup
	cleanup_all_ns
	}

	# Check that stp_mode defaults to auto when creating a bridge.
	test_default_auto()
	{
	RET=0

	ip -n "$NS1" link add br-test type bridge
	defer ip -n "$NS1" link del br-test

	check_stp_mode br-test auto "stp_mode default"

	log_test "stp_mode defaults to auto"
	}

	# Test setting stp_mode to user, kernel, and back to auto.
	test_set_modes()
	{
	RET=0

	ip -n "$NS1" link add br-test type bridge
	defer ip -n "$NS1" link del br-test

	ip -n "$NS1" link set dev br-test type bridge stp_mode user
	check_err $? "Failed to set stp_mode to user"
	check_stp_mode br-test user "after set user"

	ip -n "$NS1" link set dev br-test type bridge stp_mode kernel
	check_err $? "Failed to set stp_mode to kernel"
	check_stp_mode br-test kernel "after set kernel"

	ip -n "$NS1" link set dev br-test type bridge stp_mode auto
	check_err $? "Failed to set stp_mode to auto"
	check_stp_mode br-test auto "after set auto"

	log_test "stp_mode set user/kernel/auto"
	}

	# Verify that stp_mode cannot be changed while STP is active.
	test_reject_change_while_stp_active()
	{
	RET=0

	bridge_create br-test

	ip -n "$NS1" link set dev br-test type bridge stp_mode kernel
	check_err $? "Failed to set stp_mode to kernel"

	ip -n "$NS1" link set dev br-test type bridge stp_state 1
	check_err $? "Failed to enable STP"

	# Changing stp_mode while STP is active should fail.
	ip -n "$NS1" link set dev br-test type bridge stp_mode auto 2>/dev/null
	check_fail $? "Changing stp_mode should fail while STP is active"

	check_stp_mode br-test kernel "mode unchanged after rejected change"

	# Disable STP, then change should succeed.
	ip -n "$NS1" link set dev br-test type bridge stp_state 0
	check_err $? "Failed to disable STP"

	ip -n "$NS1" link set dev br-test type bridge stp_mode auto
	check_err $? "Changing stp_mode should succeed after STP is disabled"

	log_test "reject stp_mode change while STP is active"
	}

	# Verify that re-setting the same stp_mode while STP is active succeeds.
	test_idempotent_mode_while_stp_active()
	{
	RET=0

	bridge_create br-test

	ip -n "$NS1" link set dev br-test type bridge stp_mode user stp_state 1
	check_err $? "Failed to enable STP with user mode"

	# Re-setting the same mode while STP is active should succeed.
	ip -n "$NS1" link set dev br-test type bridge stp_mode user
	check_err $? "Idempotent stp_mode set should succeed while STP is active"

	check_stp_state br-test 2 "stp_state after idempotent set"

	# Changing mode while disabling STP in the same message should succeed.
	ip -n "$NS1" link set dev br-test type bridge stp_mode auto stp_state 0
	check_err $? "Mode change with simultaneous STP disable should succeed"

	check_stp_mode br-test auto "mode changed after disable+change"
	check_stp_state br-test 0 "stp_state after disable+change"

	log_test "idempotent and simultaneous mode change while STP active"
	}

	# Test that stp_mode user in a non-init netns yields userspace STP
	# (stp_state == 2). This is the key use case: userspace STP without
	# needing /sbin/bridge-stp or being in init_net.
	test_user_mode_in_netns()
	{
	RET=0

	bridge_create br-test

	ip -n "$NS1" link set dev br-test type bridge stp_mode user
	check_err $? "Failed to set stp_mode to user"

	ip -n "$NS1" link set dev br-test type bridge stp_state 1
	check_err $? "Failed to enable STP"

	check_stp_state br-test 2 "stp_state with user mode"

	log_test "stp_mode user in netns yields userspace STP"
	}

	# Test that stp_mode kernel forces kernel STP (stp_state == 1)
	# regardless of whether /sbin/bridge-stp exists.
	test_kernel_mode()
	{
	RET=0

	bridge_create br-test

	ip -n "$NS1" link set dev br-test type bridge stp_mode kernel
	check_err $? "Failed to set stp_mode to kernel"

	ip -n "$NS1" link set dev br-test type bridge stp_state 1
	check_err $? "Failed to enable STP"

	check_stp_state br-test 1 "stp_state with kernel mode"

	log_test "stp_mode kernel forces kernel STP"
	}

	# Test that stp_mode auto preserves traditional behavior: in a netns
	# (non-init_net), bridge-stp is not called and STP falls back to
	# kernel mode (stp_state == 1).
	test_auto_mode()
	{
	RET=0

	bridge_create br-test

	# Auto mode is the default; enable STP in a netns.
	ip -n "$NS1" link set dev br-test type bridge stp_state 1
	check_err $? "Failed to enable STP"

	# In a netns with auto mode, bridge-stp is skipped (init_net only),
	# so STP should fall back to kernel mode (stp_state == 1).
	check_stp_state br-test 1 "stp_state with auto mode in netns"

	log_test "stp_mode auto preserves traditional behavior"
	}

	# Test that stp_mode and stp_state can be set in a single netlink
	# message. This is the intended atomic usage pattern.
	test_atomic_mode_and_state()
	{
	RET=0

	bridge_create br-test

	# Set both stp_mode and stp_state in one command.
	ip -n "$NS1" link set dev br-test type bridge stp_mode user stp_state 1
	check_err $? "Failed to set stp_mode user and stp_state 1 atomically"

	check_stp_state br-test 2 "stp_state after atomic set"

	log_test "atomic stp_mode user + stp_state 1 in single message"
	}

	# Test that stp_mode persists across STP disable/enable cycles.
	test_mode_persistence()
	{
	RET=0

	bridge_create br-test

	# Set user mode and enable STP.
	ip -n "$NS1" link set dev br-test type bridge stp_mode user
	ip -n "$NS1" link set dev br-test type bridge stp_state 1
	check_err $? "Failed to enable STP with user mode"

	# Disable STP.
	ip -n "$NS1" link set dev br-test type bridge stp_state 0
	check_err $? "Failed to disable STP"

	# Verify mode is still user.
	check_stp_mode br-test user "stp_mode after STP disable"

	# Re-enable STP -- should use user mode again.
	ip -n "$NS1" link set dev br-test type bridge stp_state 1
	check_err $? "Failed to re-enable STP"

	check_stp_state br-test 2 "stp_state after re-enable"

	log_test "stp_mode persists across STP disable/enable cycles"
	}

	# Check iproute2 support before setting up resources.
	if ! ip link add type bridge help 2>&1 \| grep -q "stp_mode"; then
	echo "SKIP: iproute2 too old, missing stp_mode support"
	exit "$ksft_skip"
	fi

	trap cleanup EXIT

	setup_prepare
	tests_run

	exit "$EXIT_STATUS"