Add shell script to set base iptables rules.

docs/examples/configurations/etc.iptables.rules.v4.sh

@@ -0,0 +1,86 @@
+#!/bin/bash
+IPT="/sbin/iptables"
+ 
+ echo "Starting IPv4 Wall..."
+ $IPT -F
+ $IPT -X
+ $IPT -t nat -F
+ $IPT -t nat -X
+ $IPT -t mangle -F
+ $IPT -t mangle -X
+ $IPT -N LOGDROP
+ modprobe ip_conntrack
+  
+PUB_IFS="ens33"
+   
+#unlimited 
+$IPT -A INPUT -i lo -j ACCEPT
+$IPT -A OUTPUT -o lo -j ACCEPT
+# DROP all incomming traffic
+$IPT -P INPUT DROP
+
+$IPT -A INPUT -m state --state ESTABLISHED -j ACCEPT
+$IPT -A INPUT -p icmp -m state --state RELATED -j ACCEPT
+
+$IPT -A INPUT -m limit --limit 3/min -j LOG --log-prefix "SFW2-IN-ILL-TARGET " --log-tcp-options --log-ip-options
+$IPT -A FORWARD -m physdev --physdev-is-bridged -j ACCEPT
+$IPT -A FORWARD -m limit --limit 3/min -j LOG --log-prefix "SFW2-FWD-ILL-ROUTING " --log-tcp-options --log-ip-options
+
+for PUB_IF in $PUB_IFS
+do 
+# sync
+    $IPT -A INPUT -i ${PUB_IF} -p tcp ! --syn -m state --state NEW  -m limit --limit 5/m --limit-burst 7 -j LOG --log-level 4 --log-prefix "Drop Syn"     
+    $IPT -A INPUT -i ${PUB_IF} -p tcp ! --syn -m state --state NEW -j DROP
+           
+# Fragments
+    $IPT -A INPUT -i ${PUB_IF} -f  -m limit --limit 5/m --limit-burst 7 -j LOG --log-level 4 --log-prefix "Fragments Packets"
+    $IPT -A INPUT -i ${PUB_IF} -f -j DROP
+            
+             
+# block bad stuff
+    $IPT  -A INPUT -i ${PUB_IF} -p tcp --tcp-flags ALL FIN,URG,PSH -j DROP
+    $IPT  -A INPUT -i ${PUB_IF} -p tcp --tcp-flags ALL ALL -j DROP
+              
+    $IPT  -A INPUT -i ${PUB_IF} -p tcp --tcp-flags ALL NONE -m limit --limit 5/m --limit-burst 7 -j LOG --log-level 4 --log-prefix "NULL Packets"
+    $IPT  -A INPUT -i ${PUB_IF} -p tcp --tcp-flags ALL NONE -j DROP # NULL packets
+               
+    $IPT  -A INPUT -i ${PUB_IF} -p tcp --tcp-flags SYN,RST SYN,RST -j DROP
+                
+    $IPT  -A INPUT -i ${PUB_IF} -p tcp --tcp-flags SYN,FIN SYN,FIN -m limit --limit 5/m --limit-burst 7 -j LOG --log-level 4 --log-prefix "XMAS Packets"
+    $IPT  -A INPUT -i ${PUB_IF} -p tcp --tcp-flags SYN,FIN SYN,FIN -j DROP #XMAS
+                 
+    $IPT  -A INPUT -i ${PUB_IF} -p tcp --tcp-flags FIN,ACK FIN -m limit --limit 5/m --limit-burst 7 -j LOG --log-level 4 --log-prefix "Fin Packets Scan"
+    $IPT  -A INPUT -i ${PUB_IF} -p tcp --tcp-flags FIN,ACK FIN -j DROP # FIN packet scans
+                  
+    $IPT  -A INPUT -i ${PUB_IF} -p tcp --tcp-flags ALL SYN,RST,ACK,FIN,URG -j DROP
+                   
+    # No smb/windows sharing packets - too much logging
+    $IPT -A INPUT -p tcp -i ${PUB_IF} --dport 137:139 -j REJECT
+    $IPT -A INPUT -p udp -i ${PUB_IF} --dport 137:139 -j REJECT
+    $IPT -I INPUT -p tcp --dport 22 -i ${PUB_IF} -m state --state NEW -m recent --set
+    $IPT -I INPUT -p tcp --dport 22 -i ${PUB_IF} -m state --state NEW -m recent  --update --seconds 60 --hitcount 4 -j LOGDROP
+ done
+    # Allow full outgoing connection but no incomming stuff
+    $IPT -A INPUT -p icmp -m icmp --icmp-type 4 -j ACCEPT
+    $IPT -A OUTPUT -p icmp -m icmp --icmp-type 8 -j ACCEPT
+
+    # allow ssh/http only
+    $IPT -A INPUT -p tcp --dport 22 -j ACCEPT
+    $IPT -A INPUT -p tcp --dport 80 -j ACCEPT
+    $IPT -A INPUT -p tcp --dport 443 -j ACCEPT
+ 
+    # allow incoming ICMP ping pong stuff
+    $IPT -A INPUT -p icmp --icmp-type 8 -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT
+    $IPT -A OUTPUT -p icmp --icmp-type 0 -m state --state ESTABLISHED,RELATED -j ACCEPT
+     
+    # prevent ssh brute force attack
+    $IPT -A LOGDROP -j LOG
+    $IPT -A LOGDROP -j DROP
+
+# Log everything else
+# *** Required for psad ****
+$IPT -A INPUT -j LOG
+$IPT -A FORWARD -j LOG
+$IPT -A INPUT -j DROP
+ 
+exit 0