Add sshutter.conf to dpkg-handled configure files, update README to Debian naming scheme

DEBIAN/conffiles

@@ -0,0 +1 @@
+/etc/sshutter.conf

README.md

@@ -10,4 +10,4 @@ This situation asks for dynamic solutions. And **sshutter** is such a dynamic so
 
 ## Building/Packing
 
-To create the Debian/Ubuntu package for sshutter, run `dpkg-deb --root-owner-group --build . sshutter-v0.1.deb`
+To create the Debian/Ubuntu package for sshutter, run `dpkg-deb --root-owner-group --build . sshutter_v0.1_all.deb`

usr/sbin/sshutterd

@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/bin/bash -e
 
 function log {
 	echo "$(date +'%Y-%m-%d %H:%M:%S') $@"
@@ -10,7 +10,7 @@ if [ -f "/etc/sshutter.conf" ]; then
 fi
 
 # Check if args are given
-if [ "$WHITELIST" -eq "" ] || [ "$PORT" -eq "" ] || [ "$TARGET" -eq "" ]; then
+if [ "$WHITELIST" == "" ] || [ "$PORT" == "" ] || [ "$TARGET" == "" ]; then
 	echo "Error: you need to specify WHITELIST, PORT and TARGET, either in /etc/sshutter.conf or through environment variables." 1>&2
 	exit 1
 fi
@@ -22,18 +22,25 @@ if [ "$UID" -ne 0 ]; then
 fi
 
 # Main loop
+oldstate=""
 while [ true ]; do
 	ping -c 3 "$TARGET" 1>/dev/null
 	if [ "$?" -eq 0 ]; then
 		# Ping successful, apply shutter
-		log "[sshutter] Blocking port 22 for IPs outside $WHITELIST"
+		if [ "$oldstate" != "blocked" ]; then
+			log "[sshutter] Blocking port 22 for IPs outside $WHITELIST"
+			oldstate="blocked"
+		fi
 		nft add table inet filter
 		nft add chain inet filter sshutterv4 \{ type filter hook input priority filter \; policy accept \; \}
 		nft add rule inet filter sshutterv4 tcp dport "$PORT" ip saddr "$WHITELIST" accept
 		nft add rule inet filter sshutterv4 tcp dport "$PORT" drop
 	else
 		# Ping failed, lift shutter
-		log "[sshutter] Releasing port block"
+		if [ "$oldstate" != "released" ]; then
+			log "[sshutter] Releasing port block"
+			oldstate="released"
+		fi
 		nft destroy chain inet filter sshutterv4
 	fi