#! /usr/bin/env perl

package Jail;

use v5.10.1;
use strict;
use warnings;
use Carp;
use File::Temp qw(tempdir);
use File::Path qw(remove_tree);
use File::Copy::Recursive qw(dircopy);

use ACU::Log;

use constant {
  JAILS_DIR => "/jail/",
  RULESET_NO => 4,
};

sub run_command
{
    my $jail = shift;
    my $command = shift;
    my $readonly = shift;
    my $work_dir = shift;

    # Verifications
    croak JAILS_DIR . "$jail doesn't exist." unless ( -d JAILS_DIR . $jail);
    croak JAILS_DIR . "$jail/data doesn't exist." unless ( -d JAILS_DIR . "$jail/data");

    
    my $jail_path = JAILS_DIR . $jail;
    my $mounts = "";
    if ($readonly) {
        $jail_path = tempdir();
        $mounts  = "mount='" . JAILS_DIR . "$jail $jail_path nullfs ro 0 0' ";
    }

    $mounts .= "mount='tmpfs $jail_path/tmp tmpfs rw,mode=777 0 0' ";

    my $jail_data_path = "$jail_path/data";

    # Creating the working directory
    if (defined ($work_dir) and $work_dir ne "") {
        $mounts .= "mount='$work_dir $jail_data_path nullfs rw 0 0' ";
    }

    # Create and start jail
    my $jail_cmd = "jail -c path='$jail_path' ";
    $jail_cmd   .= "persist=false ";
    $jail_cmd   .= "devfs_ruleset=". RULESET_NO ." ";
    $jail_cmd   .= "$mounts";
    if (defined ($work_dir) and $work_dir ne "") {
        $jail_cmd   .= "exec.start='cd $jail_data_path && $command'";
    } else {
        $jail_cmd   .= "exec.start='$command'";
    }
    system($jail_cmd);
    croak "Error while executing '$jail_cmd'" if ($?);

    # Force umount
    system("umount -f $jail_path/tmp");
    if (defined ($work_dir) and $work_dir ne "") {
        system("umount -f $jail_data_path");
    }
    if ($readonly) {
        system("umount -f $jail_path");
    }
}

1;