firewall: Log packets dropped due to conntrack INVALID state

In case of faulty connection tracking, this ensures such packets are
logged, to make analysing network incidents less troublesome. Since
NewNotSYN is handled before, where logging can be turned off for systems
running on weak flash devices, the amount of log messages emitted here
should be neglectible.

Signed-off-by: Peter Müller <peter.mueller@ipfire.org>

src/initscripts/system/firewall

@@ -110,7 +110,7 @@ iptables_init() {
 	# Connection tracking chains
 	iptables -N CONNTRACK
 	iptables -A CONNTRACK -m conntrack --ctstate ESTABLISHED -j ACCEPT
-	iptables -A CONNTRACK -m conntrack --ctstate INVALID -j DROP
+	iptables -A CONNTRACK -m conntrack --ctstate INVALID -j LOG_DROP
 	iptables -A CONNTRACK -p icmp -m conntrack --ctstate RELATED -j ACCEPT
 
 	# Restore any connection marks
@@ -136,7 +136,7 @@ iptables_init() {
 	iptables -A INPUT -j P2PBLOCK
 	iptables -A FORWARD -j P2PBLOCK
 	iptables -A OUTPUT -j P2PBLOCK
-	
+
 	# IPS (Guardian) chains
 	iptables -N GUARDIAN
 	iptables -A INPUT -j GUARDIAN
@@ -265,7 +265,7 @@ iptables_init() {
 	iptables -A INPUT -j TOR_INPUT
 	iptables -N TOR_OUTPUT
 	iptables -A OUTPUT -j TOR_OUTPUT
-	
+
 	# Jump into the actual firewall ruleset.
 	iptables -N INPUTFW
 	iptables -A INPUT -j INPUTFW