selftests/net: convert fcnal-test.sh to run it in unique namespace

Here is the test result after conversion. There are some failures, but it
also exists on my system without this patch. So it's not affectec by
this patch and I will check the reason later.

  ]# time ./fcnal-test.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)

  ###########################################################################
  IPv4 ping
  ###########################################################################

  #################################################################
  No VRF

  SYSCTL: net.ipv4.raw_l3mdev_accept=0

  TEST: ping out - ns-B IP                                                      [ OK ]
  TEST: ping out, device bind - ns-B IP                                         [ OK ]
  TEST: ping out, address bind - ns-B IP                                        [ OK ]
  ...

  #################################################################
  SNAT on VRF

  TEST: IPv4 TCP connection over VRF with SNAT                                  [ OK ]
  TEST: IPv6 TCP connection over VRF with SNAT                                  [ OK ]

  Tests passed: 893
  Tests failed:  21

  real    52m48.178s
  user    0m34.158s
  sys     1m42.976s

BTW, this test needs a really long time. So expand the timeout to 1h.
Acked-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Link: https://lore.kernel.org/r/20231213060856.4030084-6-liuhangbin@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

tools/testing/selftests/net/fcnal-test.sh

@@ -37,9 +37,7 @@
 #
 # server / client nomenclature relative to ns-A
 
-# Kselftest framework requirement - SKIP code is 4.
-ksft_skip=4
-
+source lib.sh
 VERBOSE=0
 
 NSA_DEV=eth1
@@ -82,14 +80,6 @@ MCAST=ff02::1
 NSA_LINKIP6=
 NSB_LINKIP6=
 
-NSA=ns-A
-NSB=ns-B
-NSC=ns-C
-
-NSA_CMD="ip netns exec ${NSA}"
-NSB_CMD="ip netns exec ${NSB}"
-NSC_CMD="ip netns exec ${NSC}"
-
 which ping6 > /dev/null 2>&1 && ping6=$(which ping6) || ping6=$(which ping)
 
 # Check if FIPS mode is enabled
@@ -406,9 +396,6 @@ create_ns()
 	local addr=$2
 	local addr6=$3
 
-	ip netns add ${ns}
-
-	ip -netns ${ns} link set lo up
 	if [ "${addr}" != "-" ]; then
 		ip -netns ${ns} addr add dev lo ${addr}
 	fi
@@ -467,13 +454,12 @@ cleanup()
 		ip -netns ${NSA} link del dev ${NSA_DEV}
 
 		ip netns pids ${NSA} | xargs kill 2>/dev/null
-		ip netns del ${NSA}
+		cleanup_ns ${NSA}
 	fi
 
 	ip netns pids ${NSB} | xargs kill 2>/dev/null
-	ip netns del ${NSB}
 	ip netns pids ${NSC} | xargs kill 2>/dev/null
-	ip netns del ${NSC} >/dev/null 2>&1
+	cleanup_ns ${NSB} ${NSC}
 }
 
 cleanup_vrf_dup()
@@ -487,6 +473,8 @@ setup_vrf_dup()
 {
 	# some VRF tests use ns-C which has the same config as
 	# ns-B but for a device NOT in the VRF
+	setup_ns NSC
+	NSC_CMD="ip netns exec ${NSC}"
 	create_ns ${NSC} "-" "-"
 	connect_ns ${NSA} ${NSA_DEV2} ${NSA_IP}/24 ${NSA_IP6}/64 \
 		   ${NSC} ${NSC_DEV} ${NSB_IP}/24 ${NSB_IP6}/64
@@ -503,6 +491,10 @@ setup()
 	log_debug "Configuring network namespaces"
 	set -e
 
+	setup_ns NSA NSB
+	NSA_CMD="ip netns exec ${NSA}"
+	NSB_CMD="ip netns exec ${NSB}"
+
 	create_ns ${NSA} ${NSA_LO_IP}/32 ${NSA_LO_IP6}/128
 	create_ns ${NSB} ${NSB_LO_IP}/32 ${NSB_LO_IP6}/128
 	connect_ns ${NSA} ${NSA_DEV} ${NSA_IP}/24 ${NSA_IP6}/64 \
@@ -545,6 +537,10 @@ setup_lla_only()
 	log_debug "Configuring network namespaces"
 	set -e
 
+	setup_ns NSA NSB NSC
+	NSA_CMD="ip netns exec ${NSA}"
+	NSB_CMD="ip netns exec ${NSB}"
+	NSC_CMD="ip netns exec ${NSC}"
 	create_ns ${NSA} "-" "-"
 	create_ns ${NSB} "-" "-"
 	create_ns ${NSC} "-" "-"

tools/testing/selftests/net/settings

-timeout=1500
+timeout=3600