#!/usr/local/cpanel/3rdparty/bin/perl

# cpanel - scripts/build_cpnat                     Copyright 2022 cPanel, L.L.C.
#                                                           All rights reserved.
# copyright@cpanel.net                                         http://cpanel.net
# This code is subject to the cPanel license. Unauthorized copying is prohibited

package scripts::build_cpnat;

use strict;
use warnings;

use Cpanel::Config::SaveWwwAcctConf ();
use Cpanel::Config::LoadWwwAcctConf ();
use Cpanel::NAT                     ();
use Cpanel::NAT::Discovery          ();
use Cpanel::NAT::Build              ();
use Cpanel::Usage                   ();
use Cpanel::Debug                   ();

exit( run(@ARGV) ) unless caller();

sub run {

    my $man_page = 0;
    my %opts     = (
        'man' => \$man_page,
    );

    Cpanel::Usage::wrap_options( \@ARGV, \&usage, \%opts );

    return man() if $man_page;

    my $failures;

    my $cp_nat = Cpanel::NAT::Discovery->new();

    eval {
        $failures = $cp_nat->discover();

        validate_wwwacct_conf();
    };

    if ($@) {
        die $@;
    }

    Cpanel::NAT::Build::update();

    if ( keys %$failures ) {
        return 1;
    }
    return 0;
}

sub usage {
    my $prog = $0;
    $prog =~ s{^.+/(.+)$}{$1};
    print <<EOH;

$prog

    enables 1-to-1 NAT in cPanel/WHM.

$prog [options]

  Options:
    --help        print help message
    --man         print man page
EOH
    exit 0;
}

sub validate_wwwacct_conf {
    my $wwwacct    = Cpanel::Config::LoadWwwAcctConf::loadwwwacctconf();
    my $primary_ip = $wwwacct->{'ADDR'};

    return unless $primary_ip;

    my $local_ip = Cpanel::NAT::get_local_ip($primary_ip);
    return if ( $primary_ip eq $local_ip );

    # wwwacct.conf had to be fixed.
    Cpanel::Debug::log_info("Updating /etc/wwwacct.conf primary IP (ADDR) from $primary_ip to $local_ip. Local IPs, not public should be stored in most configuration files.");
    $wwwacct->{'ADDR'} = $local_ip;
    Cpanel::Config::SaveWwwAcctConf::savewwwacctconf($wwwacct);

    return;
}

sub man {
    {
        exec( "perldoc", $0 );
    }
    exit 0;
}

1;

__END__

=head1 NAME

build_cpnat - enables 1-to-1 NAT in cPanel/WHM.

=head1 SYNOPSIS

build_cpnat [options]

  Options:
    --help        print help message

=head1 DESCRIPTION

1:1 NAT mapping

When /usr/local/cpanel/scripts/build_cpnat is executed, all non-loopback IPs
bound to any network interface on the system will be used to make a connection
to a remote cPanel webserver. The remote cPanel webserver will return one public
IP for each non-loopback IP that is sent. The list of the public IPs that are
associated with the internal IPs will be written to the I</var/cpanel/cpnat>
file one mapping per line: local_ip remote_ip

=over

=item * Lines in I</var/cpanel/cpnat> with only one IP will be ignored by cPanel/WHM
because they are determined to not be publically accessible.

=item * If multipe internal IPs match the same public IP, the first internal
IP listed in the I</var/cpanel/cpnat> file will be used.

=back

By default, this script will use the L<http://myip.cpanel.net/v1.0/> URL
to detect the public IP addresses that correspond to your local IP addresses. If
you wish to override this URL, you can add an entry to the I</etc/cpsources.conf> file
corresponding to the 'MYIP' key (example below):

    MYIP=http://myip.cpanel.net/v1.0/

NOTE: This URL must return B<only> the IP address of the client connection.

=cut