[pve-devel] [PATCH v3 firewall] Don't change external ebtables rules
Stoiko Ivanov
s.ivanov at proxmox.com
Sat May 26 22:50:30 CEST 2018
* Fixes #1764
* Introduces ebtables_enable option to cluster config
* All ebtables chains not created by PVE are left in place
* get_ruleset_status optionally takes an additional argument
(a regex indicating which chains should be left intact)
Signed-off-by: Stoiko Ivanov <s.ivanov at proxmox.com>
---
Changes from V2:
* basically incorporated the feedback from w.bumiller (Thanks!!):
* removed the duplicated get_ebtables_ruleset_status at the expense of another
parameter to get_ruleset_status (with comment, since the semantics of the
parameter are not straight-forward)
* refactored get_ebtables_cmdlist to treat the appending to FORWARD a bit more
efficiently.
* dropped the bogus elseif branch in ebtables_get_chains
src/PVE/Firewall.pm | 108 +++++++++++++++++++++++++++++++---------------------
1 file changed, 64 insertions(+), 44 deletions(-)
diff --git a/src/PVE/Firewall.pm b/src/PVE/Firewall.pm
index 96cf9bd..7e2287e 100644
--- a/src/PVE/Firewall.pm
+++ b/src/PVE/Firewall.pm
@@ -1831,7 +1831,6 @@ sub ebtables_get_chains {
my $res = {};
my $chains = {};
-
my $parser = sub {
my $line = shift;
return if $line =~ m/^#/;
@@ -1839,15 +1838,7 @@ sub ebtables_get_chains {
if ($line =~ m/^:(\S+)\s\S+$/) {
# Make sure we know chains exist even if they're empty.
$chains->{$1} //= [];
- } elsif ($line =~ m/^(?:\S+)\s(PVEFW-\S+)\s(?:\S+).*/) {
- my $chain = $1;
- $line =~ s/\s+$//;
- push @{$chains->{$chain}}, $line;
- } elsif ($line =~ m/^(?:\S+)\s(tap\d+i\d+-(:?IN|OUT))\s(?:\S+).*/) {
- my $chain = $1;
- $line =~ s/\s+$//;
- push @{$chains->{$chain}}, $line;
- } elsif ($line =~ m/^(?:\S+)\s(veth\d+i\d+-(:?IN|OUT))\s(?:\S+).*/) {
+ } elsif ($line =~ m/^(?:\S+)\s(\S+)\s(?:\S+).*/) {
my $chain = $1;
$line =~ s/\s+$//;
push @{$chains->{$chain}}, $line;
@@ -1858,10 +1849,10 @@ sub ebtables_get_chains {
};
run_command("/sbin/ebtables-save", outfunc => $parser);
-
- # compute digest for each chain
+ # compute digest for each chain and store rules as well
foreach my $chain (keys %$chains) {
- $res->{$chain} = iptables_chain_digest($chains->{$chain});
+ $res->{$chain}->{rules} = $chains->{$chain};
+ $res->{$chain}->{sig} = iptables_chain_digest($chains->{$chain});
}
return $res;
}
@@ -2667,6 +2658,9 @@ sub parse_clusterfw_option {
if (($value > 1) && ((time() - $value) > 60)) {
$value = 0
}
+ } elsif ($line =~ m/^(ebtables_enable):\s*(0|1)\s*$/i) {
+ $opt = lc($1);
+ $value = int($2);
} elsif ($line =~ m/^(policy_(in|out)):\s*(ACCEPT|DROP|REJECT)\s*$/i) {
$opt = lc($1);
$value = uc($3);
@@ -3422,7 +3416,7 @@ sub compile {
$vmfw_configs = read_vm_firewall_configs($cluster_conf, $vmdata, undef, $verbose);
}
- return ({},{},{}) if !$cluster_conf->{options}->{enable};
+ return ({},{},{},{}) if !$cluster_conf->{options}->{enable};
my $localnet;
if ($cluster_conf->{aliases}->{local_network}) {
@@ -3431,7 +3425,7 @@ sub compile {
my $localnet_ver;
($localnet, $localnet_ver) = parse_ip_or_cidr(local_network() || '127.0.0.0/8');
- $cluster_conf->{aliases}->{local_network} = {
+ $cluster_conf->{aliases}->{local_network} = {
name => 'local_network', cidr => $localnet, ipversion => $localnet_ver };
}
@@ -3657,13 +3651,14 @@ sub compile_ipsets {
sub compile_ebtables_filter {
my ($cluster_conf, $hostfw_conf, $vmfw_configs, $vmdata, $verbose) = @_;
- return ({}, {}) if !$cluster_conf->{options}->{enable};
+ if (!($cluster_conf->{options}->{ebtables_enable} // 1)) {
+ return {};
+ }
my $ruleset = {};
ruleset_create_chain($ruleset, "PVEFW-FORWARD");
-
ruleset_create_chain($ruleset, "PVEFW-FWBR-OUT");
#for ipv4 and ipv6, check macaddress in iptables, so we use conntrack 'ESTABLISHED', to speedup rules
ruleset_addrule($ruleset, 'PVEFW-FORWARD', '-p IPv4', '-j ACCEPT');
@@ -3742,17 +3737,27 @@ sub generate_tap_layer2filter {
ruleset_addrule($ruleset, 'PVEFW-FWBR-OUT', "-i $iface", "-j $tapchain");
}
+# the parameter $change_only_regex changes two things if defined:
+# * all chains not matching it will be left intact
+# * both the $active_chains hash and the returned status_hash have different
+# structure (they contain a key named 'rules').
sub get_ruleset_status {
- my ($ruleset, $active_chains, $digest_fn, $verbose) = @_;
+ my ($ruleset, $active_chains, $digest_fn, $verbose, $change_only_regex) = @_;
my $statushash = {};
foreach my $chain (sort keys %$ruleset) {
- my $sig = &$digest_fn($ruleset->{$chain});
+ my $rules = $ruleset->{$chain};
+ my $sig = &$digest_fn($rules);
+ my $oldsig;
$statushash->{$chain}->{sig} = $sig;
-
- my $oldsig = $active_chains->{$chain};
+ if (defined($change_only_regex)) {
+ $oldsig = $active_chains->{$chain}->{sig};
+ $statushash->{$chain}->{rules} = $rules;
+ } else {
+ $oldsig = $active_chains->{$chain};
+ }
if (!defined($oldsig)) {
$statushash->{$chain}->{action} = 'create';
} else {
@@ -3762,19 +3767,25 @@ sub get_ruleset_status {
$statushash->{$chain}->{action} = 'update';
}
}
- print "$statushash->{$chain}->{action} $chain ($sig)\n" if $verbose;
- foreach my $cmd (@{$ruleset->{$chain}}) {
- print "\t$cmd\n" if $verbose;
+ if ($verbose) {
+ print "$statushash->{$chain}->{action} $chain ($sig)\n";
+ foreach my $cmd (@{$rules}) {
+ print "\t$cmd\n";
+ }
}
}
foreach my $chain (sort keys %$active_chains) {
- if (!defined($ruleset->{$chain})) {
- my $sig = $active_chains->{$chain};
- $statushash->{$chain}->{action} = 'delete';
- $statushash->{$chain}->{sig} = $sig;
- print "delete $chain ($sig)\n" if $verbose;
+ next if defined($ruleset->{$chain});
+ my $action = 'delete';
+ if (defined($change_only_regex)) {
+ $action = 'ignore' if ($chain !~ m/$change_only_regex/);
+ $statushash->{$chain}->{rules} = $active_chains->{$chain}->{rules};
}
+ my $sig = $active_chains->{$chain}->{sig};
+ $statushash->{$chain}->{action} = $action;
+ $statushash->{$chain}->{sig} = $sig;
+ print "$action $chain ($sig)\n" if $verbose;
}
return $statushash;
@@ -3849,35 +3860,42 @@ sub get_ruleset_cmdlist {
return wantarray ? ($cmdlist, $changes) : $cmdlist;
}
+my $pve_ebtables_chainname_regex = qr/PVEFW-\S+|(?:tab|veth)\d+i\d+-(?:IN|OUT)/;
+
sub get_ebtables_cmdlist {
my ($ruleset, $verbose) = @_;
my $changes = 0;
my $cmdlist = "*filter\n";
- my ($active_chains, $hooks) = ebtables_get_chains();
- my $statushash = get_ruleset_status($ruleset, $active_chains, \&iptables_chain_digest, $verbose);
+ my $active_chains = ebtables_get_chains();
+ my $statushash = get_ruleset_status($ruleset, $active_chains,
+ \&iptables_chain_digest, $verbose,
+ $pve_ebtables_chainname_regex);
- # create chains first
- foreach my $chain (sort keys %$ruleset) {
- my $stat = $statushash->{$chain};
- die "internal error" if !$stat;
+ # create chains first and make sure PVE rules are evaluated if active
+ my $append_pve_to_forward = '-A FORWARD -j PVEFW-FORWARD';
+ my $pve_include = 0;
+ foreach my $chain (sort keys %$statushash) {
+ next if ($statushash->{$chain}->{action} eq 'delete');
$cmdlist .= ":$chain ACCEPT\n";
+ $pve_include = 1 if ($chain eq 'PVEFW-FORWARD');
}
- if ($ruleset->{'PVEFW-FORWARD'}) {
- $cmdlist .= "-A FORWARD -j PVEFW-FORWARD\n";
- }
-
- foreach my $chain (sort keys %$ruleset) {
+ foreach my $chain (sort keys %$statushash) {
my $stat = $statushash->{$chain};
- die "internal error" if !$stat;
- $changes = 1 if ($stat->{action} ne 'exists');
+ next if ($stat->{action} eq 'delete');
+ $changes = 1 if ($stat->{action} !~ 'ignore|exists');
- foreach my $cmd (@{$ruleset->{$chain}}) {
+ foreach my $cmd (@{$statushash->{$chain}->{'rules'}}) {
+ if ($chain eq 'FORWARD' && $cmd eq $append_pve_to_forward) {
+ next if ! $pve_include;
+ $pve_include = 0;
+ }
$cmdlist .= "$cmd\n";
}
}
+ $cmdlist .= "$append_pve_to_forward\n" if $pve_include;
return wantarray ? ($cmdlist, $changes) : $cmdlist;
}
@@ -4025,7 +4043,9 @@ sub apply_ruleset {
}
my $active_ebtables_chains = ebtables_get_chains();
- my $ebtables_statushash = get_ruleset_status($ebtables_ruleset, $active_ebtables_chains, \&iptables_chain_digest, 0);
+ my $ebtables_statushash = get_ruleset_status($ebtables_ruleset,
+ $active_ebtables_chains, \&iptables_chain_digest,
+ 0, $pve_ebtables_chainname_regex);
foreach my $chain (sort keys %$ebtables_ruleset) {
my $stat = $ebtables_statushash->{$chain};
--
2.11.0
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