[pve-devel] [PATCH] add ips feature

[Alexandre Derumier]

Signed-off-by: Alexandre Derumier <aderumier at odiso.com>

This add ips (like suricata) support through nfqueues.

This replace -J ACCEPT with -J NFQUEUE on established connection when it's enabled.

it's using --queue-bypass (only available in 3.10 kernel), so it's suricata daemon is down,
packets are not dropped.

vmid.fw
-------
ips: 1

ips_queues: 0:3

1 or more queues can be defined (if we want cpu loadbalancing, or dedicated queue for a specific vm).
If not defined, default queue 0 is used.
---
 example/100.fw      |    6 ++++++
 src/PVE/Firewall.pm |   28 ++++++++++++++++++++++++----
 2 files changed, 30 insertions(+), 4 deletions(-)

diff --git a/example/100.fw b/example/100.fw
index 94f178d..880e6c3 100644
--- a/example/100.fw
+++ b/example/100.fw
@@ -28,6 +28,12 @@ tcpflags: 1
 # enable DHCP
 dhcp: 1
 
+# enable ips
+ips: 1
+
+# specify nfqueue queues (optionnal)
+#ips_queues: 0
+ips_queues: 0:3
 
 [RULES]
 
diff --git a/src/PVE/Firewall.pm b/src/PVE/Firewall.pm
index 0f2bc11..df930f4 100644
--- a/src/PVE/Firewall.pm
+++ b/src/PVE/Firewall.pm
@@ -947,7 +947,20 @@ sub ruleset_create_vm_chain {
     }
 
     ruleset_addrule($ruleset, $chain, "-m conntrack --ctstate INVALID -j DROP");
-    ruleset_addrule($ruleset, $chain, "-m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT");
+
+    if ($options->{ips} && $direction eq 'IN') {
+	my $nfqueue = "";
+	if($options->{ips_queues} && $options->{ips_queues} =~ m/^(\d+)(:(\d+))?$/) {
+	    if(defined($3) && defined($1)) {
+		$nfqueue .= "--queue-balance $1:$3";
+	    }elsif (defined($1)) {
+		$nfqueue .= "--queue-num $1";
+	    }
+	}
+	ruleset_addrule($ruleset, $chain, "-m conntrack --ctstate RELATED,ESTABLISHED -j NFQUEUE $nfqueue --queue-bypass");
+    }else{
+	ruleset_addrule($ruleset, $chain, "-m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT");
+    }
 
     if ($direction eq 'OUT') {
 	if (defined($macaddr) && !(defined($options->{macfilter}) && $options->{macfilter} == 0)) {
@@ -1320,7 +1333,7 @@ sub parse_vmfw_option {
 
     my $loglevels = "emerg|alert|crit|err|warning|notice|info|debug|nolog";
 
-    if ($line =~ m/^(enable|dhcp|macfilter|nosmurfs|tcpflags):\s*(0|1)\s*$/i) {
+    if ($line =~ m/^(enable|dhcp|macfilter|nosmurfs|tcpflags|ips):\s*(0|1)\s*$/i) {
 	$opt = lc($1);
 	$value = int($2);
     } elsif ($line =~ m/^(log_level_in|log_level_out):\s*(($loglevels)\s*)?$/i) {
@@ -1329,6 +1342,9 @@ sub parse_vmfw_option {
     } elsif ($line =~ m/^(policy_(in|out)):\s*(ACCEPT|DROP|REJECT)\s*$/i) {
 	$opt = lc($1);
 	$value = uc($3);
+    } elsif ($line =~ m/^(ips_queues):\s*((\d+)(:(\d+))?)\s*$/i) {
+	$opt = lc($1);
+	$value = $2;
     } else {
 	chomp $line;
 	die "can't parse option '$line'\n"
@@ -1690,12 +1706,14 @@ sub compile {
 
     enable_host_firewall($ruleset, $hostfw_conf, $groups_conf) if $hostfw_enable;
 
+    my $ips_enable = undef;
     # generate firewall rules for QEMU VMs
     foreach my $vmid (keys %{$vmdata->{qemu}}) {
 	my $conf = $vmdata->{qemu}->{$vmid};
 	my $vmfw_conf = $vmfw_configs->{$vmid};
 	next if !$vmfw_conf;
 	next if defined($vmfw_conf->{options}->{enable}) && ($vmfw_conf->{options}->{enable} == 0);
+        $ips_enable = 1 if $vmfw_conf->{options}->{ips};
 
 	foreach my $netid (keys %$conf) {
 	    next if $netid !~ m/^net(\d+)$/;
@@ -1725,6 +1743,7 @@ sub compile {
 	my $vmfw_conf = $vmfw_configs->{$vmid};
 	next if !$vmfw_conf;
 	next if defined($vmfw_conf->{options}->{enable}) && ($vmfw_conf->{options}->{enable} == 0);
+        $ips_enable = 1 if $vmfw_conf->{options}->{ips};
 
 	if ($conf->{ip_address} && $conf->{ip_address}->{value}) {
 	    my $ip = $conf->{ip_address}->{value};
@@ -1755,8 +1774,9 @@ sub compile {
     }
 
     # fixme: this is an optimization? if so, we should also drop INVALID packages?
-    ruleset_insertrule($ruleset, "PVEFW-FORWARD", "-m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT");
-
+    if(!$ips_enable){
+	ruleset_insertrule($ruleset, "PVEFW-FORWARD", "-m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT");
+    }
     # fixme: what log level should we use here?
     my $loglevel = get_option_log_level($hostfw_options, "log_level_out");
 
-- 
1.7.10.4