#5157 Perl error in Firewall module on Webmin 1.890

[Claudio Nicora]

Just updated Webmin to 1.890 from debian sarge repo:

# cat /etc/apt/sources.list.d/webmin.list
deb http://download.webmin.com/download/repository sarge contrib

and I get this error when opening "Linux Firewall" module:

HTTP/1.0 500 Perl execution failed Server: MiniServ/1.890 Date: Wed, 18 Jul 2018 10:28:12 GMT Content-type: text/html; Charset=iso-8859-1 Connection: close

Error - Perl execution failed

Undefined subroutine &net::get_interface_defs called at debian-linux-lib.pl line 63. 

Webmin worked perfectly before updating to 1.890

[Claudio Nicora]

Sorry, missed system details:
Ubuntu 18.04 Server x64

[Claudio Nicora]

Just downgraded to 1.883 and it works, reupdated to 1.890 and "Linux Firewall" module stopped working again.

Additional note: bug is only on Ubuntu 18.04, no issues on Ubuntu 16.04.4.

Ubuntu 18.04 Server
-------------------
webmin-1.883: OK
webmin-1.890: NOT OK

Ubuntu 16.04.4 Server
---------------------
webmin-1.883: OK
webmin-1.890: OK

[Sandro Santos]

Same error in Ubuntu 17.10 (ipv4 and ipv6)

[Act Pohomoc]

Ubuntu Linux 18.04 Desktop
Same error:

Rules file /etc/iptables.up.rules
HTTP/1.0 500 Perl execution failed Server: MiniServ/1.890 Date: Fri, 20 Jul 2018 08:34:20 GMT Content-type: text/html; Charset=iso-8859-1 Connection: close
Error - Perl execution failed
Undefined subroutine &net::get_interface_defs called at debian-linux-lib.pl line 63.

[Act Pohomoc]

I have found the solution. At least for now:
https://github.com/webmin/webmin/issues/941

[Act Pohomoc]

Just add that:

 if (&foreign_check("net")) { 
        &foreign_require("net");
        if (defined(&net::get_interface_def)) {

total sub is:

# started_at_boot()
sub started_at_boot
{
&foreign_require("init", "init-lib.pl");
if ($has_debian_iptables) {
    # Check Debian init script
    return &init::action_status("ip${ipvx}tables") == 2;
    }
elsif ($has_new_debian_iptables) {
    # Check network interface config
    local $pri = &get_primary_network_interface();
   if (&foreign_check("net")) { 
        &foreign_require("net");
        if (defined(&net::get_interface_def)) {
            local ($debpri) = grep { $_->[0] eq $pri->{'fullname'} }
                       &net::get_interface_def();
            foreach my $o (@{$debpri->[3]}) {
                if (($o->[0] eq "pre-up" || $o->[0] eq "post-up") &&
                    $o->[1] =~ /\S*ip${ipvx}tables-restore\s+<\s+(\S+)/ &&
                    $1 eq $ipvx_save) {
                    return 1;
                    }
                }
            }
        }
    }
else {
    # Check Webmin init script
    return &init::action_status("webmin-ip${ipvx}tables") == 2;
    }
}