selftests: netfilter: conntrack_resize.sh: also use udpclash tool

Previous patch added a new clash resolution test case.
Also use this during conntrack resize stress test in addition
to icmp ping flood.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Author: Florian Westphal

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

@@ -177,6 +177,22 @@ EOF
 	done
 }
 
+ct_udpclash()
+{
+	local ns="$1"
+	local duration="$2"
+	local now=$(date +%s)
+	local end=$((now + duration))
+
+	[ -x udpclash ] || return
+
+        while [ $now -lt $end ]; do
+		ip netns exec "$ns" ./udpclash 127.0.0.1 $((RANDOM%65536)) > /dev/null 2>&1
+
+		now=$(date +%s)
+	done
+}
+
 # dump to /dev/null.  We don't want dumps to cause infinite loops
 # or use-after-free even when conntrack table is altered while dumps
 # are in progress.
@@ -267,6 +283,7 @@ insert_flood()
 
 	ct_pingflood "$n" "$timeout" "floodresize" &
 	ct_udpflood "$n" "$timeout" &
+	ct_udpclash "$n" "$timeout" &
 
 	insert_ctnetlink "$n" "$r" &
 	ctflush "$n" "$timeout" &