BCP38: don't slow down established connections (#2838)

Enabling BCP38 causes an iptables rule to be inserted before this rule:
ACCEPT     all  --  anywhere             anywhere             ID:66773300 ctstate RELATED,ESTABLISHED

This makes all forwarded packets go through the BCP38 ipset match, which slows
down download speed from 440 Mbit/s to 340 Mbit/s.

Only apply BCP38 match rules if state is NEW.

Bump package version.

Signed-off-by: Török Edwin <edwin@skylable.com>

net/bcp38/Makefile

@@ -6,7 +6,7 @@
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=bcp38
-PKG_VERSION:=4
+PKG_VERSION:=5
 PKG_RELEASE:=1
 PKG_LICENCE:=GPL-3.0+
 

net/bcp38/files/run.sh

@@ -72,9 +72,9 @@ setup_iptables()
 	iptables -N "$IPTABLES_CHAIN" 2>/dev/null
 	iptables -F "$IPTABLES_CHAIN" 2>/dev/null
 
-	iptables -I output_rule -j "$IPTABLES_CHAIN"
-	iptables -I input_rule -j "$IPTABLES_CHAIN"
-	iptables -I forwarding_rule -j "$IPTABLES_CHAIN"
+	iptables -I output_rule -m state --state NEW -j "$IPTABLES_CHAIN"
+	iptables -I input_rule -m state --state NEW -j "$IPTABLES_CHAIN"
+	iptables -I forwarding_rule -m state --state NEW -j "$IPTABLES_CHAIN"
 
 	# always accept DHCP traffic
 	iptables -A "$IPTABLES_CHAIN" -p udp --dport 67:68 --sport 67:68 -j RETURN
@@ -90,9 +90,9 @@ destroy_ipset()
 
 destroy_iptables()
 {
-	iptables -D output_rule -j "$IPTABLES_CHAIN" 2>/dev/null
-	iptables -D input_rule -j "$IPTABLES_CHAIN" 2>/dev/null
-	iptables -D forwarding_rule -j "$IPTABLES_CHAIN" 2>/dev/null
+	iptables -D output_rule -m state --state NEW -j "$IPTABLES_CHAIN" 2>/dev/null
+	iptables -D input_rule -m state --state NEW -j "$IPTABLES_CHAIN" 2>/dev/null
+	iptables -D forwarding_rule -m state --state NEW -j "$IPTABLES_CHAIN" 2>/dev/null
 	iptables -F "$IPTABLES_CHAIN" 2>/dev/null
 	iptables -X "$IPTABLES_CHAIN" 2>/dev/null
 }