Rework nft_removeall.sh to preserve nftables structures miniupnpd didn't add. Important for firewalld and sshguard co-existance.

miniupnpd/netfilter_nft/scripts/nft_removeall.sh

@@ -1,4 +1,44 @@
 #!/bin/sh
+#
+# Undo the things nft_init.sh did
+#
+# Do not disturb other existing structures in nftables, e.g. those created by firewalld
+#
 
-# Remove all rules in nft not just miniupnpd
+nft --check list table nat > /dev/null 2>&1
-nft flush ruleset
+if [ $? -eq "0" ]; then
+{
+	# nat table exists, so first remove the chains we added
+	nft --check list chain nat MINIUPNPD > /dev/null 2>&1
+	if [ $? -eq "0" ]; then
+		echo "Remove chain from nat table"
+		nft delete chain nat MINIUPNPD
+	fi
+
+	nft --check list chain nat MINIUPNPD-POSTROUTING > /dev/null 2>&1
+	if [ $? -eq "0" ]; then
+		echo "Remove pcp peer chain from nat table"
+		nft delete chain nat MINIUPNPD-POSTROUTING
+	fi
+
+	# then remove the table itself
+	echo "Remove nat table"
+	nft delete table nat
+}
+fi
+
+nft --check list table inet filter > /dev/null 2>&1
+if [ $? -eq "0" ]; then
+{
+	# filter table exists, so first remove the chain we added
+	nft --check list chain inet filter MINIUPNPD > /dev/null 2>&1
+	if [ $? -eq "0" ]; then
+		echo "Remove chain from filter table"
+		nft delete chain inet filter MINIUPNPD
+	fi
+
+	# then remove the table itself
+	echo "Remove filter table"
+	nft delete table inet filter
+}
+fi