Iptables not found in Ubuntu 20.04

[elliotjberg]

I was previously running a Ubuntu 18.04 server with PSAD configured and working as expected, which I recently upgraded to 20.04. Since doing so, PSAD won't start - it gives the error Could not find/execute iptables, specify path via _iptables at /usr/share/perl5/IPTables/ChainMgr.pm line 37. I have edited /etc/psad/psad.conf and changed

iptablesCmd      /sbin/iptables;
ip6tablesCmd     /sbin/ip6tables;

to

iptablesCmd      /usr/sbin/iptables;
ip6tablesCmd     /usr/sbin/ip6tables;

to match where iptables is on the filesystem;

which iptables
/usr/sbin/iptables

But this makes no difference. I have also tried setting

ENABLE_OVERRIDE_FW_CMD Y;
FW_CMD /usr/sbin/iptables;

Which also seems to make no difference. I'm running v2.4.3 from the Ubuntu repositories.

Any indication as to how I can address this?

[andweber]

I had the same problem - quick and dirty solution:
sudo ln -s /usr/sbin/iptables /sbin/iptables
sudo ln -s /usr/sbin/ip6tables /sbin/ip6tables

It looks like IPTables::ChainMgr use the defaults defined in IPTables::Parse.
While on the other side according to

psad/psad

Lines 3445 to 3462 in 8720f6a

	### set some config variables based on command line input
	&handle_cmdline();
	$ipt_opts{'tmpdir'} = $config{'PSAD_TMP_DIR'};
	$ipt_opts{'iptout_pat'} = $config{'IPT_OUTPUT_PATTERN'};
	$ipt_opts{'ipterr_pat'} = $config{'IPT_ERROR_PATTERN'};
	$ipt_opts{'debug'} = 1 if $debug;
	$ipt_opts{'verbose'} = 1 if $verbose;
	if ($config{'ENABLE_OVERRIDE_FW_CMD'} eq 'Y') {
	if ($config{'FW_CMD_ARGS'} ne 'NONE') {
	$ipt_opts{'firewall-cmd'} = $config{'FW_CMD'};
	$ipt_opts{'fwd_args'} = $config{'FW_CMD_ARGS'};
	} else {
	$ipt_opts{'iptables'} = $config{'FW_CMD'};
	}
	}

it doesn't look like psad was designed to pass the iptablesCmd config options down to IPTables:ChainMgr.

[daydr3am3r]

@mrash this looks like an easy fix, is it possible to update lines 32-34 of Parse.pm of the IPTables::Parse module to obtain the binary locations from the environment?

Version 1.6.1 reads:

    ### default iptables/ip6tables/firewall-cmd paths
    my $ipt_bin    = '/sbin/iptables';
    my $ipt6_bin   = '/sbin/ip6tables';
    my $fwc_bin    = '/usr/bin/firewall-cmd';