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

 #!/bin/bash
 # SPDX-License-Identifier: GPL-2.0
 #
 # By Seth Schoen (c) 2021, for the IPv4 Unicast Extensions Project
 # Thanks to David Ahern for help and advice on nettest modifications.
 #
 # Self-tests for IPv4 address extensions: the kernel's ability to accept
 # certain traditionally unused or unallocated IPv4 addresses. For each kind
 # of address, we test for interface assignment, ping, TCP, and forwarding.
 # Must be run as root (to manipulate network namespaces and virtual
 # interfaces).
 #
 # Things we test for here:
 #
 # * Currently the kernel accepts addresses in 0/8 and 240/4 as valid.
 #
 # * Notwithstanding that, 0.0.0.0 and 255.255.255.255 cannot be assigned.
 #
 # * Currently the kernel DOES NOT accept unicast use of the lowest
 #   address in an IPv4 subnet (e.g. 192.168.100.0/32 in 192.168.100.0/24).
 #   This is treated as a second broadcast address, for compatibility
 #   with 4.2BSD (!).
 #
 # * Currently the kernel DOES NOT accept unicast use of any of 127/8.
 #
 # * Currently the kernel DOES NOT accept unicast use of any of 224/4.
 #
 # These tests provide an easy way to flip the expected result of any
 # of these behaviors for testing kernel patches that change them.

 source lib.sh

 # nettest can be run from PATH or from same directory as this selftest
 if ! which nettest >/dev/null; then
 	PATH=$PWD:$PATH
 	if ! which nettest >/dev/null; then
 		echo "'nettest' command not found; skipping tests"
 		exit $ksft_skip
 	fi
 fi

 result=0

 hide_output(){ exec 3>&1 4>&2 >/dev/null 2>/dev/null; }
 show_output(){ exec >&3 2>&4; }

 show_result(){
 	if [ $1 -eq 0 ]; then
 		printf "TEST: %-60s  [ OK ]\n" "${2}"
 	else
 		printf "TEST: %-60s  [FAIL]\n" "${2}"
 		result=1
 	fi
 }

 _do_segmenttest(){
 	# Perform a simple set of link tests between a pair of
 	# IP addresses on a shared (virtual) segment, using
 	# ping and nettest.
 	# foo --- bar
 	# Arguments: ip_a ip_b prefix_length test_description
 	#
 	# Caller must set up $foo_ns and $bar_ns namespaces
 	# containing linked veth devices foo and bar,
 	# respectively.

 	ip -n $foo_ns address add $1/$3 dev foo || return 1
 	ip -n $foo_ns link set foo up || return 1
 	ip -n $bar_ns address add $2/$3 dev bar || return 1
 	ip -n $bar_ns link set bar up || return 1

 	ip netns exec $foo_ns timeout 2 ping -c 1 $2 || return 1
 	ip netns exec $bar_ns timeout 2 ping -c 1 $1 || return 1

 	nettest -B -N $bar_ns -O $foo_ns -r $1 || return 1
 	nettest -B -N $foo_ns -O $bar_ns -r $2 || return 1

 	return 0
 }

 _do_route_test(){
 	# Perform a simple set of gateway tests.
 	#
 	# [foo] <---> [foo1]-[bar1] <---> [bar]   /prefix
 	#  host          gateway          host
 	#
 	# Arguments: foo_ip foo1_ip bar1_ip bar_ip prefix_len test_description
 	# Displays test result and returns success or failure.

 	# Caller must set up $foo_ns, $bar_ns, and $router_ns
 	# containing linked veth devices foo-foo1, bar1-bar
 	# (foo in $foo_ns, foo1 and bar1 in $router_ns, and
 	# bar in $bar_ns).

 	ip -n $foo_ns address add $1/$5 dev foo || return 1
 	ip -n $foo_ns link set foo up || return 1
 	ip -n $foo_ns route add default via $2 || return 1
 	ip -n $bar_ns address add $4/$5 dev bar || return 1
 	ip -n $bar_ns link set bar up || return 1
 	ip -n $bar_ns route add default via $3 || return 1
 	ip -n $router_ns address add $2/$5 dev foo1 || return 1
 	ip -n $router_ns link set foo1 up || return 1
 	ip -n $router_ns address add $3/$5 dev bar1 || return 1
 	ip -n $router_ns link set bar1 up || return 1

 	echo 1 | ip netns exec $router_ns tee /proc/sys/net/ipv4/ip_forward

 	ip netns exec $foo_ns timeout 2 ping -c 1 $2 || return 1
 	ip netns exec $foo_ns timeout 2 ping -c 1 $4 || return 1
 	ip netns exec $bar_ns timeout 2 ping -c 1 $3 || return 1
 	ip netns exec $bar_ns timeout 2 ping -c 1 $1 || return 1

 	nettest -B -N $bar_ns -O $foo_ns -r $1 || return 1
 	nettest -B -N $foo_ns -O $bar_ns -r $4 || return 1

 	return 0
 }

 segmenttest(){
 	# Sets up veth link and tries to connect over it.
 	# Arguments: ip_a ip_b prefix_len test_description
 	hide_output
 	setup_ns foo_ns bar_ns
 	ip link add foo netns $foo_ns type veth peer name bar netns $bar_ns

 	test_result=0
 	_do_segmenttest "$@" || test_result=1

 	ip netns pids $foo_ns | xargs -r kill -9
 	ip netns pids $bar_ns | xargs -r kill -9
 	cleanup_ns $foo_ns $bar_ns
 	show_output

 	# inverted tests will expect failure instead of success
 	[ -n "$expect_failure" ] && test_result=`expr 1 - $test_result`

 	show_result $test_result "$4"
 }

 route_test(){
 	# Sets up a simple gateway and tries to connect through it.
 	# [foo] <---> [foo1]-[bar1] <---> [bar]   /prefix
 	# Arguments: foo_ip foo1_ip bar1_ip bar_ip prefix_len test_description
 	# Returns success or failure.

 	hide_output
 	setup_ns foo_ns bar_ns router_ns
 	ip link add foo netns $foo_ns type veth peer name foo1 netns $router_ns
 	ip link add bar netns $bar_ns type veth peer name bar1 netns $router_ns

 	test_result=0
 	_do_route_test "$@" || test_result=1

 	ip netns pids $foo_ns | xargs -r kill -9
 	ip netns pids $bar_ns | xargs -r kill -9
 	ip netns pids $router_ns | xargs -r kill -9
 	cleanup_ns $foo_ns $bar_ns $router_ns

 	show_output

 	# inverted tests will expect failure instead of success
 	[ -n "$expect_failure" ] && test_result=`expr 1 - $test_result`
 	show_result $test_result "$6"
 }

 echo "###########################################################################"
 echo "Unicast address extensions tests (behavior of reserved IPv4 addresses)"
 echo "###########################################################################"
 #
 # Test support for 240/4
 segmenttest 240.1.2.1   240.1.2.4    24 "assign and ping within 240/4 (1 of 2) (is allowed)"
 segmenttest 250.100.2.1 250.100.30.4 16 "assign and ping within 240/4 (2 of 2) (is allowed)"
 #
 # Test support for 0/8
 segmenttest 0.1.2.17    0.1.2.23  24 "assign and ping within 0/8 (1 of 2) (is allowed)"
 segmenttest 0.77.240.17 0.77.2.23 16 "assign and ping within 0/8 (2 of 2) (is allowed)"
 #
 # Even 255.255/16 is OK!
 segmenttest 255.255.3.1 255.255.50.77 16 "assign and ping inside 255.255/16 (is allowed)"
 #
 # Or 255.255.255/24
 segmenttest 255.255.255.1 255.255.255.254 24 "assign and ping inside 255.255.255/24 (is allowed)"
 #
 # Routing between different networks
 route_test 240.5.6.7 240.5.6.1  255.1.2.1    255.1.2.3      24 "route between 240.5.6/24 and 255.1.2/24 (is allowed)"
 route_test 0.200.6.7 0.200.38.1 245.99.101.1 245.99.200.111 16 "route between 0.200/16 and 245.99/16 (is allowed)"
 #
 # Test support for lowest address ending in .0
 segmenttest 5.10.15.20 5.10.15.0 24 "assign and ping lowest address (/24)"
 #
 # Test support for lowest address not ending in .0
 segmenttest 192.168.101.192 192.168.101.193 26 "assign and ping lowest address (/26)"
 #
 # Routing using lowest address as a gateway/endpoint
 route_test 192.168.42.1 192.168.42.0 9.8.7.6 9.8.7.0 24 "routing using lowest address"
 #
 # ==============================================
 # ==== TESTS THAT CURRENTLY EXPECT FAILURE =====
 # ==============================================
 expect_failure=true
 # It should still not be possible to use 0.0.0.0 or 255.255.255.255
 # as a unicast address.  Thus, these tests expect failure.
 segmenttest 0.0.1.5       0.0.0.0         16 "assigning 0.0.0.0 (is forbidden)"
 segmenttest 255.255.255.1 255.255.255.255 16 "assigning 255.255.255.255 (is forbidden)"
 #
 # Test support for not having all of 127 be loopback
 # Currently Linux does not allow this, so this should fail too
 segmenttest 127.99.4.5 127.99.4.6 16 "assign and ping inside 127/8 (is forbidden)"
 #
 # Test support for unicast use of class D
 # Currently Linux does not allow this, so this should fail too
 segmenttest 225.1.2.3 225.1.2.200 24 "assign and ping class D address (is forbidden)"
 #
 # Routing using class D as a gateway
 route_test 225.1.42.1 225.1.42.2 9.8.7.6 9.8.7.1 24 "routing using class D (is forbidden)"
 #
 # Routing using 127/8
 # Currently Linux does not allow this, so this should fail too
 route_test 127.99.2.3 127.99.2.4 200.1.2.3 200.1.2.4 24 "routing using 127/8 (is forbidden)"
 #
 unset expect_failure
 # =====================================================
 # ==== END OF TESTS THAT CURRENTLY EXPECT FAILURE =====
 # =====================================================
 exit ${result}
	#!/bin/bash
	# SPDX-License-Identifier: GPL-2.0
	#
	# By Seth Schoen (c) 2021, for the IPv4 Unicast Extensions Project
	# Thanks to David Ahern for help and advice on nettest modifications.
	#
	# Self-tests for IPv4 address extensions: the kernel's ability to accept
	# certain traditionally unused or unallocated IPv4 addresses. For each kind
	# of address, we test for interface assignment, ping, TCP, and forwarding.
	# Must be run as root (to manipulate network namespaces and virtual
	# interfaces).
	#
	# Things we test for here:
	#
	# * Currently the kernel accepts addresses in 0/8 and 240/4 as valid.
	#
	# * Notwithstanding that, 0.0.0.0 and 255.255.255.255 cannot be assigned.
	#
	# * Currently the kernel DOES NOT accept unicast use of the lowest
	# address in an IPv4 subnet (e.g. 192.168.100.0/32 in 192.168.100.0/24).
	# This is treated as a second broadcast address, for compatibility
	# with 4.2BSD (!).
	#
	# * Currently the kernel DOES NOT accept unicast use of any of 127/8.
	#
	# * Currently the kernel DOES NOT accept unicast use of any of 224/4.
	#
	# These tests provide an easy way to flip the expected result of any
	# of these behaviors for testing kernel patches that change them.

	source lib.sh

	# nettest can be run from PATH or from same directory as this selftest
	if ! which nettest >/dev/null; then
	PATH=$PWD:$PATH
	if ! which nettest >/dev/null; then
	echo "'nettest' command not found; skipping tests"
	exit $ksft_skip
	fi
	fi

	result=0

	hide_output(){ exec 3>&1 4>&2 >/dev/null 2>/dev/null; }
	show_output(){ exec >&3 2>&4; }

	show_result(){
	if [ $1 -eq 0 ]; then
	printf "TEST: %-60s [ OK ]\n" "${2}"
	else
	printf "TEST: %-60s [FAIL]\n" "${2}"
	result=1
	fi
	}

	_do_segmenttest(){
	# Perform a simple set of link tests between a pair of
	# IP addresses on a shared (virtual) segment, using
	# ping and nettest.
	# foo --- bar
	# Arguments: ip_a ip_b prefix_length test_description
	#
	# Caller must set up $foo_ns and $bar_ns namespaces
	# containing linked veth devices foo and bar,
	# respectively.

	ip -n $foo_ns address add $1/$3 dev foo \|\| return 1
	ip -n $foo_ns link set foo up \|\| return 1
	ip -n $bar_ns address add $2/$3 dev bar \|\| return 1
	ip -n $bar_ns link set bar up \|\| return 1

	ip netns exec $foo_ns timeout 2 ping -c 1 $2 \|\| return 1
	ip netns exec $bar_ns timeout 2 ping -c 1 $1 \|\| return 1

	nettest -B -N $bar_ns -O $foo_ns -r $1 \|\| return 1
	nettest -B -N $foo_ns -O $bar_ns -r $2 \|\| return 1

	return 0
	}

	_do_route_test(){
	# Perform a simple set of gateway tests.
	#
	# [foo] <---> [foo1]-[bar1] <---> [bar] /prefix
	# host gateway host
	#
	# Arguments: foo_ip foo1_ip bar1_ip bar_ip prefix_len test_description
	# Displays test result and returns success or failure.

	# Caller must set up $foo_ns, $bar_ns, and $router_ns
	# containing linked veth devices foo-foo1, bar1-bar
	# (foo in $foo_ns, foo1 and bar1 in $router_ns, and
	# bar in $bar_ns).

	ip -n $foo_ns address add $1/$5 dev foo \|\| return 1
	ip -n $foo_ns link set foo up \|\| return 1
	ip -n $foo_ns route add default via $2 \|\| return 1
	ip -n $bar_ns address add $4/$5 dev bar \|\| return 1
	ip -n $bar_ns link set bar up \|\| return 1
	ip -n $bar_ns route add default via $3 \|\| return 1
	ip -n $router_ns address add $2/$5 dev foo1 \|\| return 1
	ip -n $router_ns link set foo1 up \|\| return 1
	ip -n $router_ns address add $3/$5 dev bar1 \|\| return 1
	ip -n $router_ns link set bar1 up \|\| return 1

	echo 1 \| ip netns exec $router_ns tee /proc/sys/net/ipv4/ip_forward

	ip netns exec $foo_ns timeout 2 ping -c 1 $2 \|\| return 1
	ip netns exec $foo_ns timeout 2 ping -c 1 $4 \|\| return 1
	ip netns exec $bar_ns timeout 2 ping -c 1 $3 \|\| return 1
	ip netns exec $bar_ns timeout 2 ping -c 1 $1 \|\| return 1

	nettest -B -N $bar_ns -O $foo_ns -r $1 \|\| return 1
	nettest -B -N $foo_ns -O $bar_ns -r $4 \|\| return 1

	return 0
	}

	segmenttest(){
	# Sets up veth link and tries to connect over it.
	# Arguments: ip_a ip_b prefix_len test_description
	hide_output
	setup_ns foo_ns bar_ns
	ip link add foo netns $foo_ns type veth peer name bar netns $bar_ns

	test_result=0
	_do_segmenttest "$@" \|\| test_result=1

	ip netns pids $foo_ns \| xargs -r kill -9
	ip netns pids $bar_ns \| xargs -r kill -9
	cleanup_ns $foo_ns $bar_ns
	show_output

	# inverted tests will expect failure instead of success
	[ -n "$expect_failure" ] && test_result=`expr 1 - $test_result`

	show_result $test_result "$4"
	}

	route_test(){
	# Sets up a simple gateway and tries to connect through it.
	# [foo] <---> [foo1]-[bar1] <---> [bar] /prefix
	# Arguments: foo_ip foo1_ip bar1_ip bar_ip prefix_len test_description
	# Returns success or failure.

	hide_output
	setup_ns foo_ns bar_ns router_ns
	ip link add foo netns $foo_ns type veth peer name foo1 netns $router_ns
	ip link add bar netns $bar_ns type veth peer name bar1 netns $router_ns

	test_result=0
	_do_route_test "$@" \|\| test_result=1

	ip netns pids $foo_ns \| xargs -r kill -9
	ip netns pids $bar_ns \| xargs -r kill -9
	ip netns pids $router_ns \| xargs -r kill -9
	cleanup_ns $foo_ns $bar_ns $router_ns

	show_output

	# inverted tests will expect failure instead of success
	[ -n "$expect_failure" ] && test_result=`expr 1 - $test_result`
	show_result $test_result "$6"
	}

	echo "###########################################################################"
	echo "Unicast address extensions tests (behavior of reserved IPv4 addresses)"
	echo "###########################################################################"
	#
	# Test support for 240/4
	segmenttest 240.1.2.1 240.1.2.4 24 "assign and ping within 240/4 (1 of 2) (is allowed)"
	segmenttest 250.100.2.1 250.100.30.4 16 "assign and ping within 240/4 (2 of 2) (is allowed)"
	#
	# Test support for 0/8
	segmenttest 0.1.2.17 0.1.2.23 24 "assign and ping within 0/8 (1 of 2) (is allowed)"
	segmenttest 0.77.240.17 0.77.2.23 16 "assign and ping within 0/8 (2 of 2) (is allowed)"
	#
	# Even 255.255/16 is OK!
	segmenttest 255.255.3.1 255.255.50.77 16 "assign and ping inside 255.255/16 (is allowed)"
	#
	# Or 255.255.255/24
	segmenttest 255.255.255.1 255.255.255.254 24 "assign and ping inside 255.255.255/24 (is allowed)"
	#
	# Routing between different networks
	route_test 240.5.6.7 240.5.6.1 255.1.2.1 255.1.2.3 24 "route between 240.5.6/24 and 255.1.2/24 (is allowed)"
	route_test 0.200.6.7 0.200.38.1 245.99.101.1 245.99.200.111 16 "route between 0.200/16 and 245.99/16 (is allowed)"
	#
	# Test support for lowest address ending in .0
	segmenttest 5.10.15.20 5.10.15.0 24 "assign and ping lowest address (/24)"
	#
	# Test support for lowest address not ending in .0
	segmenttest 192.168.101.192 192.168.101.193 26 "assign and ping lowest address (/26)"
	#
	# Routing using lowest address as a gateway/endpoint
	route_test 192.168.42.1 192.168.42.0 9.8.7.6 9.8.7.0 24 "routing using lowest address"
	#
	# ==============================================
	# ==== TESTS THAT CURRENTLY EXPECT FAILURE =====
	# ==============================================
	expect_failure=true
	# It should still not be possible to use 0.0.0.0 or 255.255.255.255
	# as a unicast address. Thus, these tests expect failure.
	segmenttest 0.0.1.5 0.0.0.0 16 "assigning 0.0.0.0 (is forbidden)"
	segmenttest 255.255.255.1 255.255.255.255 16 "assigning 255.255.255.255 (is forbidden)"
	#
	# Test support for not having all of 127 be loopback
	# Currently Linux does not allow this, so this should fail too
	segmenttest 127.99.4.5 127.99.4.6 16 "assign and ping inside 127/8 (is forbidden)"
	#
	# Test support for unicast use of class D
	# Currently Linux does not allow this, so this should fail too
	segmenttest 225.1.2.3 225.1.2.200 24 "assign and ping class D address (is forbidden)"
	#
	# Routing using class D as a gateway
	route_test 225.1.42.1 225.1.42.2 9.8.7.6 9.8.7.1 24 "routing using class D (is forbidden)"
	#
	# Routing using 127/8
	# Currently Linux does not allow this, so this should fail too
	route_test 127.99.2.3 127.99.2.4 200.1.2.3 200.1.2.4 24 "routing using 127/8 (is forbidden)"
	#
	unset expect_failure
	# =====================================================
	# ==== END OF TESTS THAT CURRENTLY EXPECT FAILURE =====
	# =====================================================
	exit ${result}