selftests: netfilter: nft_synproxy.sh: move to lib.sh infra

use checktool helper where applicable.
Signed-off-by: Florian Westphal <fw@strlen.de>
Link: https://lore.kernel.org/r/20240418152744.15105-4-fw@strlen.deSigned-off-by: Jakub Kicinski <kuba@kernel.org>

tools/testing/selftests/net/netfilter/nft_synproxy.sh

 #!/bin/bash
 # SPDX-License-Identifier: GPL-2.0
-#
 
-# Kselftest framework requirement - SKIP code is 4.
-ksft_skip=4
-ret=0
-
-rnd=$(mktemp -u XXXXXXXX)
-nsr="nsr-$rnd"	# synproxy machine
-ns1="ns1-$rnd"  # iperf client
-ns2="ns2-$rnd"  # iperf server
+source lib.sh
 
-checktool (){
-	if ! $1 > /dev/null 2>&1; then
-		echo "SKIP: Could not $2"
-		exit $ksft_skip
-	fi
-}
+ret=0
 
 checktool "nft --version" "run test without nft tool"
-checktool "ip -Version" "run test without ip tool"
 checktool "iperf3 --version" "run test without iperf3"
-checktool "ip netns add $nsr" "create net namespace"
 
-modprobe -q nf_conntrack
+setup_ns nsr ns1 ns2
 
-ip netns add $ns1
-ip netns add $ns2
+modprobe -q nf_conntrack
 
 cleanup() {
-	ip netns pids $ns1 | xargs kill 2>/dev/null
-	ip netns pids $ns2 | xargs kill 2>/dev/null
-	ip netns del $ns1
-	ip netns del $ns2
+	ip netns pids "$ns1" | xargs kill 2>/dev/null
+	ip netns pids "$ns2" | xargs kill 2>/dev/null
 
-	ip netns del $nsr
+	cleanup_all_ns
 }
 
 trap cleanup EXIT
 
-ip link add veth0 netns $nsr type veth peer name eth0 netns $ns1
-ip link add veth1 netns $nsr type veth peer name eth0 netns $ns2
+ip link add veth0 netns "$nsr" type veth peer name eth0 netns "$ns1"
+ip link add veth1 netns "$nsr" type veth peer name eth0 netns "$ns2"
 
-for dev in lo veth0 veth1; do
-ip -net $nsr link set $dev up
+for dev in veth0 veth1; do
+	ip -net "$nsr" link set "$dev" up
 done
 
-ip -net $nsr addr add 10.0.1.1/24 dev veth0
-ip -net $nsr addr add 10.0.2.1/24 dev veth1
+ip -net "$nsr" addr add 10.0.1.1/24 dev veth0
+ip -net "$nsr" addr add 10.0.2.1/24 dev veth1
 
-ip netns exec $nsr sysctl -q net.ipv4.conf.veth0.forwarding=1
-ip netns exec $nsr sysctl -q net.ipv4.conf.veth1.forwarding=1
-ip netns exec $nsr sysctl -q net.netfilter.nf_conntrack_tcp_loose=0
+ip netns exec "$nsr" sysctl -q net.ipv4.conf.veth0.forwarding=1
+ip netns exec "$nsr" sysctl -q net.ipv4.conf.veth1.forwarding=1
+ip netns exec "$nsr" sysctl -q net.netfilter.nf_conntrack_tcp_loose=0
 
 for n in $ns1 $ns2; do
-  ip -net $n link set lo up
-  ip -net $n link set eth0 up
+  ip -net "$n" link set eth0 up
 done
-ip -net $ns1 addr add 10.0.1.99/24 dev eth0
-ip -net $ns2 addr add 10.0.2.99/24 dev eth0
-ip -net $ns1 route add default via 10.0.1.1
-ip -net $ns2 route add default via 10.0.2.1
+ip -net "$ns1" addr add 10.0.1.99/24 dev eth0
+ip -net "$ns2" addr add 10.0.2.99/24 dev eth0
+ip -net "$ns1" route add default via 10.0.1.1
+ip -net "$ns2" route add default via 10.0.2.1
 
 # test basic connectivity
-if ! ip netns exec $ns1 ping -c 1 -q 10.0.2.99 > /dev/null; then
+if ! ip netns exec "$ns1" ping -c 1 -q 10.0.2.99 > /dev/null; then
   echo "ERROR: $ns1 cannot reach $ns2" 1>&2
   exit 1
 fi
 
-if ! ip netns exec $ns2 ping -c 1 -q 10.0.1.99 > /dev/null; then
+if ! ip netns exec "$ns2" ping -c 1 -q 10.0.1.99 > /dev/null; then
   echo "ERROR: $ns2 cannot reach $ns1" 1>&2
   exit 1
 fi
 
-ip netns exec $ns2 iperf3 -s > /dev/null 2>&1 &
+ip netns exec "$ns2" iperf3 -s > /dev/null 2>&1 &
 # ip netns exec $nsr tcpdump -vvv -n -i veth1 tcp | head -n 10 &
 
 sleep 1
 
-ip netns exec $nsr nft -f - <<EOF
+ip netns exec "$nsr" nft -f - <<EOF
 table inet filter {
    chain prerouting {
       type filter hook prerouting priority -300; policy accept;
@@ -104,12 +85,10 @@ if [ $? -ne 0 ]; then
 	exit $ksft_skip
 fi
 
-ip netns exec $ns1 timeout 5 iperf3 -c 10.0.2.99 -n $((1 * 1024 * 1024)) > /dev/null
-
-if [ $? -ne 0 ]; then
+if ! ip netns exec "$ns1" timeout 5 iperf3 -c 10.0.2.99 -n $((1 * 1024 * 1024)) > /dev/null; then
 	echo "FAIL: iperf3 returned an error" 1>&2
-	ret=$?
-	ip netns exec $nsr nft list ruleset
+	ret=1
+	ip netns exec "$nsr" nft list ruleset
 else
 	echo "PASS: synproxy connection successful"
 fi