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

Replace nc with socat. Too many different implementations of nc
are around with incompatible options ("nc: cannot use -p and -l").
Signed-off-by: Florian Westphal <fw@strlen.de>
Link: https://lore.kernel.org/r/20240411233624.8129-6-fw@strlen.deSigned-off-by: Jakub Kicinski <kuba@kernel.org>

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

@@ -4,37 +4,29 @@
 # Check that UNREPLIED tcp conntrack will eventually timeout.
 #
 
-# Kselftest framework requirement - SKIP code is 4.
-ksft_skip=4
-ret=0
-
-waittime=20
-sfx=$(mktemp -u "XXXXXXXX")
-ns1="ns1-$sfx"
-ns2="ns2-$sfx"
+source lib.sh
 
-nft --version > /dev/null 2>&1
-if [ $? -ne 0 ];then
+if ! nft --version > /dev/null 2>&1;then
 	echo "SKIP: Could not run test without nft tool"
 	exit $ksft_skip
 fi
 
-ip -Version > /dev/null 2>&1
-if [ $? -ne 0 ];then
-	echo "SKIP: Could not run test without ip tool"
+if ! conntrack --version > /dev/null 2>&1;then
+	echo "SKIP: Could not run test without conntrack tool"
 	exit $ksft_skip
 fi
 
+ret=0
+
 cleanup() {
-	ip netns pids $ns1 | xargs kill 2>/dev/null
-	ip netns pids $ns2 | xargs kill 2>/dev/null
+	ip netns pids "$ns1" | xargs kill 2>/dev/null
+	ip netns pids "$ns2" | xargs kill 2>/dev/null
 
-	ip netns del $ns1
-	ip netns del $ns2
+	cleanup_all_ns
 }
 
 ipv4() {
-    echo -n 192.168.$1.2
+    echo -n 192.168."$1".2
 }
 
 check_counter()
@@ -44,51 +36,53 @@ check_counter()
 	expect=$3
 	local lret=0
 
-	cnt=$(ip netns exec $ns2 nft list counter inet filter "$name" | grep -q "$expect")
-	if [ $? -ne 0 ]; then
+	if ! ip netns exec "$ns2" nft list counter inet filter "$name" | grep -q "$expect"; then
 		echo "ERROR: counter $name in $ns2 has unexpected value (expected $expect)" 1>&2
-		ip netns exec $ns2 nft list counter inet filter "$name" 1>&2
+		ip netns exec "$ns2" nft list counter inet filter "$name" 1>&2
 		lret=1
 	fi
 
 	return $lret
 }
 
-# Create test namespaces
-ip netns add $ns1 || exit 1
-
 trap cleanup EXIT
 
-ip netns add $ns2 || exit 1
+# Create test namespaces
+setup_ns ns1 ns2
 
 # Connect the namespace to the host using a veth pair
-ip -net $ns1 link add name veth1 type veth peer name veth2
-ip -net $ns1 link set netns $ns2 dev veth2
+ip -net "$ns1" link add name veth1 type veth peer name veth2
+ip -net "$ns1" link set netns "$ns2" dev veth2
 
-ip -net $ns1 link set up dev lo
-ip -net $ns2 link set up dev lo
-ip -net $ns1 link set up dev veth1
-ip -net $ns2 link set up dev veth2
+ip -net "$ns1" link set up dev lo
+ip -net "$ns2" link set up dev lo
+ip -net "$ns1" link set up dev veth1
+ip -net "$ns2" link set up dev veth2
 
-ip -net $ns2 addr add 10.11.11.2/24 dev veth2
-ip -net $ns2 route add default via 10.11.11.1
+ip -net "$ns2" addr add 10.11.11.2/24 dev veth2
+ip -net "$ns2" route add default via 10.11.11.1
 
-ip netns exec $ns2 sysctl -q net.ipv4.conf.veth2.forwarding=1
+ip netns exec "$ns2" sysctl -q net.ipv4.conf.veth2.forwarding=1
 
 # add a rule inside NS so we enable conntrack
-ip netns exec $ns1 iptables -A INPUT -m state --state established,related -j ACCEPT
+ip netns exec "$ns1" nft -f - <<EOF
+table inet filter {
+	chain input {
+		type filter hook input priority 0; policy accept;
+		ct state established accept
+	}
+}
+EOF
 
-ip -net $ns1 addr add 10.11.11.1/24 dev veth1
-ip -net $ns1 route add 10.99.99.99 via 10.11.11.2
+ip -net "$ns1" addr add 10.11.11.1/24 dev veth1
+ip -net "$ns1" route add 10.99.99.99 via 10.11.11.2
 
 # Check connectivity works
-ip netns exec $ns1 ping -q -c 2 10.11.11.2 >/dev/null || exit 1
-
-ip netns exec $ns2 nc -l -p 8080 < /dev/null &
+ip netns exec "$ns1" ping -q -c 2 10.11.11.2 >/dev/null || exit 1
 
-# however, conntrack entries are there
+ip netns exec "$ns2" socat -u -4 TCP-LISTEN:8080,reuseaddr STDOUT &
 
-ip netns exec $ns2 nft -f - <<EOF
+ip netns exec "$ns2" nft -f - <<EOF
 table inet filter {
 	counter connreq { }
 	counter redir { }
@@ -104,17 +98,15 @@ if [ $? -ne 0 ]; then
 	exit 1
 fi
 
-ip netns exec $ns2 sysctl -q net.netfilter.nf_conntrack_tcp_timeout_syn_sent=10
+ip netns exec "$ns2" sysctl -q net.netfilter.nf_conntrack_tcp_timeout_syn_sent=10
 
 echo "INFO: connect $ns1 -> $ns2 to the virtual ip"
-ip netns exec $ns1 bash -c 'while true ; do
-	nc -p 60000 10.99.99.99 80
-	sleep 1
+ip netns exec "$ns1" bash -c 'for i in $(seq 1 $BUSYWAIT_TIMEOUT) ; do
+	socat -u STDIN TCP:10.99.99.99:80 < /dev/null
+	sleep 0.1
 	done' &
 
-sleep 1
-
-ip netns exec $ns2 nft -f - <<EOF
+ip netns exec "$ns2" nft -f - <<EOF
 table inet nat {
 	chain prerouting {
 		type nat hook prerouting priority 0; policy accept;
@@ -127,34 +119,28 @@ if [ $? -ne 0 ]; then
 	exit 1
 fi
 
-count=$(ip netns exec $ns2 conntrack -L -p tcp --dport 80 2>/dev/null | wc -l)
-if [ $count -eq 0 ]; then
+count=$(ip netns exec "$ns2" conntrack -L -p tcp --dport 80 2>/dev/null | wc -l)
+if [ "$count" -eq 0 ]; then
 	echo "ERROR: $ns2 did not pick up tcp connection from peer"
 	exit 1
 fi
 
-echo "INFO: NAT redirect added in ns $ns2, waiting for $waittime seconds for nat to take effect"
-for i in $(seq 1 $waittime); do
-	echo -n "."
-
-	sleep 1
-
-	count=$(ip netns exec $ns2 conntrack -L -p tcp --reply-port-src 8080 2>/dev/null | wc -l)
-	if [ $count -gt 0 ]; then
-		echo
-		echo "PASS: redirection took effect after $i seconds"
-		break
+wait_for_redirect()
+{
+	count=$(ip netns exec "$ns2" conntrack -L -p tcp --reply-port-src 8080 2>/dev/null | wc -l)
+	if [ "$count" -gt 0 ]; then
+		return 0
 	fi
 
-	m=$((i%20))
-	if [ $m -eq 0 ]; then
-		echo " waited for $i seconds"
-	fi
-done
+	return 1
+}
+echo "INFO: NAT redirect added in ns $ns2, waiting for $BUSYWAIT_TIMEOUT ms for nat to take effect"
+
+busywait $BUSYWAIT_TIMEOUT wait_for_redirect
+ret=$?
 
 expect="packets 1 bytes 60"
-check_counter "$ns2" "redir" "$expect"
-if [ $? -ne 0 ]; then
+if ! check_counter "$ns2" "redir" "$expect"; then
 	ret=1
 fi