Anonymous functions and safe compartments

[David Emanuel da Costa Santiago]

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Hello!


How do i run and pass arguments to an anonymous subroutine that i shared
on a safe compartment?

My goal is to have a function that perform "dangerous" operations, that
must be available to untrusted code, however this function needs some
parameters that are only available when the code is executing, and the
untrusted code doesn't know them (hence the anonymous subroutine).

Example (35 lines):

### Example.pl file
use strict;
use warnings;
use Safe;
use 5.020;

my $UNTRUSTED_SCRIPT="untrusted_script.pl";

sub run_me{

  my $sandbox = Safe->new("Sandbox");
  $sandbox->permit(qw(:base_core :base_loop :base_mem :base_io :load 
:base_orig));
  $sandbox->deny(qw(die exit));

  my $operation = "Dangerous";
  
  my $anon_func = sub{
    my $param = shift;
    print "$operation $param operation!\n";
  };

  $sandbox->share($anon_func);
  $sandbox->rdo($UNTRUSTED_SCRIPT);
  $sandbox->reval('func1()');
}

run_me();

### untrusted_script.pl
use 5.020;
use warnings;
use utf8;


sub func1{
  say "About to run shared function!";
  $anon_func->("func1");
}

######

The output of the Example.pl script is:

Error while executing the sandbox: Global symbol "$anon_func" requires
explicit package name at untrusted_script.pl line 5. 

I was expecting of the output of the Example.pl script to be
"Dangerous func1 operation!". What am i doing wrong?


Best regards,
David Santiago
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