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

Here is the test result after conversion.

]# ./ndisc_unsolicited_na_test.sh
    TEST: test_unsolicited_na:  drop_unsolicited_na=0  accept_untracked_na=1  forwarding=1  [ OK ]
    TEST: test_unsolicited_na:  drop_unsolicited_na=0  accept_untracked_na=0  forwarding=0  [ OK ]
    TEST: test_unsolicited_na:  drop_unsolicited_na=0  accept_untracked_na=0  forwarding=1  [ OK ]
    TEST: test_unsolicited_na:  drop_unsolicited_na=0  accept_untracked_na=1  forwarding=0  [ OK ]
    TEST: test_unsolicited_na:  drop_unsolicited_na=1  accept_untracked_na=0  forwarding=0  [ OK ]
    TEST: test_unsolicited_na:  drop_unsolicited_na=1  accept_untracked_na=0  forwarding=1  [ OK ]
    TEST: test_unsolicited_na:  drop_unsolicited_na=1  accept_untracked_na=1  forwarding=0  [ OK ]
    TEST: test_unsolicited_na:  drop_unsolicited_na=1  accept_untracked_na=1  forwarding=1  [ OK ]

Tests passed:   8
Tests failed:   0
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/ndisc_unsolicited_na_test.sh

@@ -10,16 +10,12 @@
 #    0        1       0  Don't update NC
 #    0        1       1  Add a STALE NC entry
 
+source lib.sh
 ret=0
-# Kselftest framework requirement - SKIP code is 4.
-ksft_skip=4
 
 PAUSE_ON_FAIL=no
 PAUSE=no
 
-HOST_NS="ns-host"
-ROUTER_NS="ns-router"
-
 HOST_INTF="veth-host"
 ROUTER_INTF="veth-router"
 
@@ -29,11 +25,6 @@ SUBNET_WIDTH=64
 ROUTER_ADDR_WITH_MASK="${ROUTER_ADDR}/${SUBNET_WIDTH}"
 HOST_ADDR_WITH_MASK="${HOST_ADDR}/${SUBNET_WIDTH}"
 
-IP_HOST="ip -6 -netns ${HOST_NS}"
-IP_HOST_EXEC="ip netns exec ${HOST_NS}"
-IP_ROUTER="ip -6 -netns ${ROUTER_NS}"
-IP_ROUTER_EXEC="ip netns exec ${ROUTER_NS}"
-
 tcpdump_stdout=
 tcpdump_stderr=
 
@@ -76,8 +67,12 @@ setup()
 
 	# Setup two namespaces and a veth tunnel across them.
 	# On end of the tunnel is a router and the other end is a host.
-	ip netns add ${HOST_NS}
-	ip netns add ${ROUTER_NS}
+	setup_ns HOST_NS ROUTER_NS
+	IP_HOST="ip -6 -netns ${HOST_NS}"
+	IP_HOST_EXEC="ip netns exec ${HOST_NS}"
+	IP_ROUTER="ip -6 -netns ${ROUTER_NS}"
+	IP_ROUTER_EXEC="ip netns exec ${ROUTER_NS}"
+
 	${IP_ROUTER} link add ${ROUTER_INTF} type veth \
                 peer name ${HOST_INTF} netns ${HOST_NS}