selftests/net: convert unicast_extensions.sh to run it in unique namespace

Here is the test result after conversion.

 # ./unicast_extensions.sh
 /usr/bin/which: no nettest in (/root/.local/bin:/root/bin:/usr/share/Modules/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin)
 ###########################################################################
 Unicast address extensions tests (behavior of reserved IPv4 addresses)
 ###########################################################################
 TEST: assign and ping within 240/4 (1 of 2) (is allowed)            [ OK ]
 TEST: assign and ping within 240/4 (2 of 2) (is allowed)            [ OK ]
 TEST: assign and ping within 0/8 (1 of 2) (is allowed)              [ OK ]

 ...

 TEST: assign and ping class D address (is forbidden)                [ OK ]
 TEST: routing using class D (is forbidden)                          [ OK ]
 TEST: routing using 127/8 (is forbidden)                            [ OK ]
Acked-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

tools/testing/selftests/net/unicast_extensions.sh

@@ -28,8 +28,7 @@
 # These tests provide an easy way to flip the expected result of any
 # of these behaviors for testing kernel patches that change them.
 
-# Kselftest framework requirement - SKIP code is 4.
-ksft_skip=4
+source ./lib.sh
 
 # nettest can be run from PATH or from same directory as this selftest
 if ! which nettest >/dev/null; then
@@ -61,20 +60,20 @@ _do_segmenttest(){
 	# foo --- bar
 	# Arguments: ip_a ip_b prefix_length test_description
 	#
-	# Caller must set up foo-ns and bar-ns namespaces
+	# 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 -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
+	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
+	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
 }
@@ -88,31 +87,31 @@ _do_route_test(){
 	# 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
+	# 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
+	# (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
 }
@@ -121,17 +120,15 @@ segmenttest(){
 	# Sets up veth link and tries to connect over it.
 	# Arguments: ip_a ip_b prefix_len test_description
 	hide_output
-	ip netns add foo-ns
-	ip netns add bar-ns
-	ip link add foo netns foo-ns type veth peer name bar netns bar-ns
+	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
-	ip netns del foo-ns
-	ip netns del bar-ns
+	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
@@ -147,21 +144,17 @@ route_test(){
 	# Returns success or failure.
 
 	hide_output
-	ip netns add foo-ns
-	ip netns add bar-ns
-	ip netns add 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
+	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
-	ip netns del foo-ns
-	ip netns del bar-ns
-	ip netns del router-ns
+	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