implement nosmurfs options (enabled by default)

[pve-firewall.git] / PVE / Firewall.pm

diff --git a/PVE/Firewall.pm b/PVE/Firewall.pm
index 887c56016f6512ed82f4189807d7102f84727b77..1a74652ab0fe6db5bac7004b51902c2fb181917c 100644 (file)
--- a/PVE/Firewall.pm
+++ b/PVE/Firewall.pm
@@ -418,7 +418,7 @@ my $pve_std_chains = {
        { action => 'DROP', proto => 'udp', sport => 53 },
     ],
     'PVEFW-logflags' => [
-       # same as shorewall logflags action.
+       # same as shorewall logflags action. (fixme: enable/disable logging)
        "-j LOG --log-prefix \"logflags-dropped:\" --log-level 4 --log-ip-options",
        "-j DROP",
     ],
@@ -431,6 +431,18 @@ my $pve_std_chains = {
        "-p tcp -m tcp --tcp-flags FIN,SYN FIN,SYN -g PVEFW-logflags",
        "-p tcp -m tcp --sport 0 --tcp-flags FIN,SYN,RST,ACK SYN -g PVEFW-logflags",
     ],
+    'PVEFW-smurflog' => [
+       # same as shorewall smurflog. (fixme: enable/disable logging)
+       "-j LOG --log-prefix \"smurfs-dropped\" --log-level 4",
+       "-j DROP",
+    ],
+    'PVEFW-smurfs' => [
+       # same as shorewall smurfs action
+       # Filter packets for smurfs (packets with a broadcast address as the source).
+       "-s 0.0.0.0/32 -j RETURN",
+       "-m addrtype --src-type BROADCAST -g PVEFW-smurflog",
+       "-s 224.0.0.0/4 -g PVEFW-smurflog",
+    ],
 };
 
 # iptables -p icmp -h
@@ -817,6 +829,14 @@ sub generate_tap_rules_direction {
 
     ruleset_create_chain($ruleset, $tapchain);
 
+    if (!(defined($options->{nosmurfs}) && $options->{nosmurfs} == 0)) {
+       ruleset_addrule($ruleset, $tapchain, "-m conntrack --ctstate INVALID,NEW -j PVEFW-smurfs");
+    }
+
+    if ($options->{tcpflags}) {
+       ruleset_addrule($ruleset, $tapchain, "-p tcp -j PVEFW-tcpflags");
+    }
+
     ruleset_addrule($ruleset, $tapchain, "-m conntrack --ctstate INVALID -j DROP");
     ruleset_addrule($ruleset, $tapchain, "-m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT");
 
@@ -825,9 +845,6 @@ sub generate_tap_rules_direction {
        ruleset_addrule($ruleset, $tapchain, "-m mac ! --mac-source $macaddr -j DROP");
     }
 
-    if ($options->{tcpflags}) {
-       ruleset_addrule($ruleset, $tapchain, "-p tcp -j PVEFW-tcpflags");
-    }
 
     if ($rules) {
         foreach my $rule (@$rules) {
@@ -1096,7 +1113,7 @@ sub parse_fw_option {
 
     my ($opt, $value);
 
-    if ($line =~ m/^(enable|macfilter|tcpflags):\s*(0|1)\s*$/i) {
+    if ($line =~ m/^(enable|macfilter|nosmurfs|tcpflags):\s*(0|1)\s*$/i) {
        $opt = lc($1);
        $value = int($2);
     } elsif ($line =~ m/^(policy-(in|out)):\s*(ACCEPT|DROP|REJECT)\s*$/i) {