perl/lib/Thrasher/Plugin/REPL.pm

   1 package Thrasher::Plugin::REPL;
   2 use strict;
   3 use warnings;
   4
   5 use Thrasher::EventLoop;
   6 use Thrasher::Log;
   7 use Thrasher::Plugin qw(register_plugin);
   8
   9 ### Plugin init
  10 #
  11 # Subclass that integrates itself into a Thrasher::EventLoop.
  12 #
  13 # Warning 1: Anyone who can connect to the REPL port can inject
  14 # arbitrary Perl code into the Thrasher process. The only security
  15 # measure currently used is binding only to the IPv4 loopback
  16 # interface.
  17 #
  18 # Warning 2: A REPL iteration blocks the main loop, so it would be
  19 # best to avoid long-lived computations!
  20 use base qw(Net::REPL::Server);
  21
  22 our $repl_server;
  23 sub integrate_repl {
  24     my ($component) = @_;
  25
  26     $repl_server ||= Thrasher::Plugin::REPL->new(
  27         'event_loop' => $component->{'event_loop'},
  28         'debug' => 1,
  29         'socket_args' => {
  30             # path in abstract namespace instead of FS
  31             'Local' => "\x00"
  32               . '/Thrasher/REPL/' . $component->{'component_name'},
  33         },
  34     );
  35 }
  36
  37 register_plugin({
  38     'callbacks' => {
  39         'main_loop' => { 'Integrate REPL' => \&integrate_repl },
  40     },
  41 });
  42
  43 ### REPL::Server callbacks
  44
  45 sub debug {
  46     my ($self, @words) = @_;
  47
  48     if ($self->{'debug'}) {
  49         my $line = join(' ', @words);
  50         Thrasher::Log::debug($line, $self->{'debug'});
  51     }
  52 }
  53
  54 sub cb_listen {
  55     my ($self) = @_;
  56
  57     $self->SUPER::cb_listen();
  58
  59     $self->{'event_loop'}->add_fd_watch(
  60         $self->{'server'}->fileno(),
  61         $Thrasher::EventLoop::IN,
  62         sub {
  63             $self->interact();
  64             return 1;
  65         }
  66     );
  67 }
  68
  69 sub cb_connect {
  70     my ($self) = @_;
  71
  72     $self->SUPER::cb_connect();
  73
  74     $self->{'fh_watch_id'} =
  75       $self->{'event_loop'}->add_fd_watch(
  76           $self->{'fh'}->fileno(),
  77           $Thrasher::EventLoop::IN,
  78           sub {
  79               return $self->interact();
  80           }
  81     );
  82 }
  83
  84 sub cb_disconnect {
  85     my ($self) = @_;
  86
  87     $self->SUPER::cb_disconnect();
  88
  89     if ($self->{'fh_watch_id'}) {
  90         $self->{'event_loop'}->remove_fd_watch($self->{'fh_watch_id'});
  91         $self->{'fh_watch_id'} = undef;
  92     }
  93 }
  94
  95 1;