selftests/net: convert srv6_end_dt4_l3vpn_test.sh to run it in unique namespace

As the name \${rt-${rt}} may make reader confuse, convert the variable
hs/rt in setup_rt/hs to hid, rid. Here is the test result after conversion.

 ]# ./srv6_end_dt4_l3vpn_test.sh

 ################################################################################
 TEST SECTION: IPv6 routers connectivity test
 ################################################################################

     TEST: Routers connectivity: rt-1 -> rt-2                            [ OK ]

     TEST: Routers connectivity: rt-2 -> rt-1                            [ OK ]
 ...
     TEST: Hosts isolation: hs-t200-4 -X-> hs-t100-2                     [ OK ]

 Tests passed:  18
 Tests failed:   0
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Link: https://lore.kernel.org/r/20231213060856.4030084-4-liuhangbin@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

tools/testing/selftests/net/srv6_end_dt4_l3vpn_test.sh

@@ -163,8 +163,7 @@
 # +---------------------------------------------------+
 #
 
-# Kselftest framework requirement - SKIP code is 4.
-ksft_skip=4
+source lib.sh
 
 readonly LOCALSID_TABLE_ID=90
 readonly IPv6_RT_NETWORK=fd00
@@ -219,27 +218,22 @@ cleanup()
 	ip link del veth-rt-1 2>/dev/null || true
 	ip link del veth-rt-2 2>/dev/null || true
 
-	# destroy routers rt-* and hosts hs-*
-	for ns in $(ip netns show | grep -E 'rt-*|hs-*'); do
-		ip netns del ${ns} || true
-	done
+	cleanup_all_ns
 }
 
 # Setup the basic networking for the routers
 setup_rt_networking()
 {
-	local rt=$1
-	local nsname=rt-${rt}
-
-	ip netns add ${nsname}
+	local id=$1
+	eval local nsname=\${rt_${id}}
 
 	ip netns exec ${nsname} sysctl -wq net.ipv6.conf.all.accept_dad=0
 	ip netns exec ${nsname} sysctl -wq net.ipv6.conf.default.accept_dad=0
 
-	ip link set veth-rt-${rt} netns ${nsname}
-	ip -netns ${nsname} link set veth-rt-${rt} name veth0
+	ip link set veth-rt-${id} netns ${nsname}
+	ip -netns ${nsname} link set veth-rt-${id} name veth0
 
-	ip -netns ${nsname} addr add ${IPv6_RT_NETWORK}::${rt}/64 dev veth0 nodad
+	ip -netns ${nsname} addr add ${IPv6_RT_NETWORK}::${id}/64 dev veth0 nodad
 	ip -netns ${nsname} link set veth0 up
 	ip -netns ${nsname} link set lo up
 
@@ -249,16 +243,13 @@ setup_rt_networking()
 
 setup_hs()
 {
-	local hs=$1
-	local rt=$2
+	local hid=$1
+	local rid=$2
 	local tid=$3
-	local hsname=hs-t${tid}-${hs}
-	local rtname=rt-${rt}
+	eval local hsname=\${hs_t${tid}_${hid}}
+	eval local rtname=\${rt_${rid}}
 	local rtveth=veth-t${tid}
 
-	# set the networking for the host
-	ip netns add ${hsname}
-
 	# disable the rp_filter otherwise the kernel gets confused about how
 	# to route decap ipv4 packets.
 	ip netns exec ${rtname} sysctl -wq net.ipv4.conf.all.rp_filter=0
@@ -266,7 +257,7 @@ setup_hs()
 
 	ip -netns ${hsname} link add veth0 type veth peer name ${rtveth}
 	ip -netns ${hsname} link set ${rtveth} netns ${rtname}
-	ip -netns ${hsname} addr add ${IPv4_HS_NETWORK}.${hs}/24 dev veth0
+	ip -netns ${hsname} addr add ${IPv4_HS_NETWORK}.${hid}/24 dev veth0
 	ip -netns ${hsname} link set veth0 up
 	ip -netns ${hsname} link set lo up
 
@@ -293,10 +284,8 @@ setup_vpn_config()
 	local rtdst=$4
 	local tid=$5
 
-	local hssrc_name=hs-t${tid}-${hssrc}
-	local hsdst_name=hs-t${tid}-${hsdst}
-	local rtsrc_name=rt-${rtsrc}
-	local rtdst_name=rt-${rtdst}
+	eval local rtsrc_name=\${rt_${rtsrc}}
+	eval local rtdst_name=\${rt_${rtdst}}
 	local vpn_sid=${VPN_LOCATOR_SERVICE}:${hssrc}${hsdst}:${tid}::6004
 
 	# set the encap route for encapsulating packets which arrive from the
@@ -328,18 +317,21 @@ setup()
 {
 	ip link add veth-rt-1 type veth peer name veth-rt-2
 	# setup the networking for router rt-1 and router rt-2
+	setup_ns rt_1 rt_2
 	setup_rt_networking 1
 	setup_rt_networking 2
 
 	# setup two hosts for the tenant 100.
 	#  - host hs-1 is directly connected to the router rt-1;
 	#  - host hs-2 is directly connected to the router rt-2.
+	setup_ns hs_t100_1 hs_t100_2
 	setup_hs 1 1 100  #args: host router tenant
 	setup_hs 2 2 100
 
 	# setup two hosts for the tenant 200
 	#  - host hs-3 is directly connected to the router rt-1;
 	#  - host hs-4 is directly connected to the router rt-2.
+	setup_ns hs_t200_3 hs_t200_4
 	setup_hs 3 1 200
 	setup_hs 4 2 200
 
@@ -358,8 +350,9 @@ check_rt_connectivity()
 {
 	local rtsrc=$1
 	local rtdst=$2
+	eval local nsname=\${rt_${rtsrc}}
 
-	ip netns exec rt-${rtsrc} ping -c 1 -W 1 ${IPv6_RT_NETWORK}::${rtdst} \
+	ip netns exec ${nsname} ping -c 1 -W 1 ${IPv6_RT_NETWORK}::${rtdst} \
 		>/dev/null 2>&1
 }
 
@@ -377,8 +370,9 @@ check_hs_connectivity()
 	local hssrc=$1
 	local hsdst=$2
 	local tid=$3
+	eval local nsname=\${hs_t${tid}_${hssrc}}
 
-	ip netns exec hs-t${tid}-${hssrc} ping -c 1 -W ${PING_TIMEOUT_SEC} \
+	ip netns exec ${nsname} ping -c 1 -W ${PING_TIMEOUT_SEC} \
 		${IPv4_HS_NETWORK}.${hsdst} >/dev/null 2>&1
 }