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

# cpanel - scripts/fix-listen-on-localhost         Copyright 2022 cPanel, L.L.C.
#                                                           All rights reserved.
# [email protected]                                         http://cpanel.net
# This code is subject to the cPanel license. Unauthorized copying is prohibited

use strict;
use warnings;
use Cpanel::Usage                   ();
use Cpanel::Update::Logger          ();
use Cpanel::NameServer::Utils::BIND ();
use Cpanel::FileUtils               ();

# not tidy
my $force   = 0;
my $verbose = 0;
my $debug   = 0;

# default value comes from Cpanel::NameServer::Utils::BIND
my $file = Cpanel::NameServer::Utils::BIND::find_namedconf();

my %opts = (
    'force'   => \$force,
    'verbose' => \$verbose,
    'debug'   => \$debug,
    'file'    => \$file,
);

# ==== init process options

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

# set logger ( default level to fatal )
my $level = $verbose ? 'info' : 'fatal';
$level = 'debug' if $debug;
my $logger = Cpanel::Update::Logger->new( { 'stdout' => 1, 'log_level' => $level } );

# ==== main code start here

my @files = ($file);

# add extra file if chroot is enable
my ($chrootdir) = Cpanel::NameServer::Utils::BIND::find_chrootbinddir();
push( @files, join( $chrootdir, '/', $file ) )
  if $chrootdir && $chrootdir ne '';

# fix for each file
my $need_to_reload;
foreach my $f (@files) {
    $need_to_reload ||= fix_file( file => $f, force => $force );
}

# relaod service if possible
if ($need_to_reload) {
    require Cpanel::DnsUtils::RNDCQueue::Adder;
    require Cpanel::ServerTasks;
    Cpanel::DnsUtils::RNDCQueue::Adder->add("reload");
    Cpanel::ServerTasks::schedule_task( ['BINDTasks'], 1, 'rndc_queue' );
}

exit;

### helpers

sub fix_file {
    my (%opts) = @_;

    $logger->info("file candidate : $file");

    eval { _check_prerequire( \%opts ); };
    return if ($@);
    $logger->info("file $file will be fixed");

    # replace safely the file line at this step
    # listen-on { 127.0.0.1; }; => listen-on { any; };
    Cpanel::FileUtils::regex_rep_file(
        $opts{file},
        {
            qr{^\s*listen\-on.*{\s*127.0.0.1;\s*};\s*$} => q{    listen-on { any; }; /*      updated by cPanel*/\n},
        }
    );

    1;
}

sub _check_prerequire {
    my ($opts) = @_;

    my $file = $opts->{file};

    # do not apply force on these set of prerequires
    _die_and_next("No file defined")            unless defined $file;
    _die_and_next("File '$file' doesn't exist") unless -e $file;

    # these ones can be disables using force option
    return if $opts->{force};

    # basic prerequire to avoid to touch file if not needed
    system("grep listen-on $file | grep -v '//' | grep 127.0.0.1 >/dev/null");
    _die_and_next("cannot find listen-on 127.0.0.1") unless $? == 0;
}

sub _die_and_next {
    my $msg = shift || 'Unknown error';
    $logger->error($msg);
    die($msg);
}

sub usage {
    my $prog = $0;
    $prog =~ s{^.+/(.+)$}{$1};
    print <<EOF;
$prog [options] [ -f FILE ]

This script will convert the default listen-on entry in named.conf from
    listen-on { 127.0.0.1; };
to a more widely entry
    listen-on { any; };

Only works on IPv4.

Parameters:
    --file=FILE, -f FILE - you can specify a FILE default one will be /etc/namedb/named.conf

Modifiers Flags:

    --force - will update the file without checking any conditions
    --verbose - display some friendly verbose messages
    --debug - display more messages
    --help - dislay this help message and exit
EOF
    exit;
}