#!/usr/bin/perl
# ------------------------------------------------------------------
#
#    Copyright (C) 2011-2013 Canonical Ltd.
#
#    This program is free software; you can redistribute it and/or
#    modify it under the terms of version 2 of the GNU General Public
#    License published by the Free Software Foundation.
#
# ------------------------------------------------------------------

use strict;
use warnings;
use Errno;

require LibAppArmor;
require POSIX;

my $opt_d = '';
my $opt_h = '';
my $opt_p = '';
my $opt_n = '';
my $opt_i = '';
my $opt_v = '';
my $opt_f = '';

sub _warn {
    my $msg = $_[0];
    print STDERR "aa-exec: WARN: $msg\n";
}
sub _error {
    my $msg = $_[0];
    print STDERR "aa-exec: ERROR: $msg\n";
    exit 1
}

sub _debug {
    $opt_d or return;
    my $msg = $_[0];
    print STDERR "aa-exec: DEBUG: $msg\n";
}

sub _verbose {
    $opt_v or return;
    my $msg = $_[0];
    print STDERR "$msg\n";
}

sub usage() {
    my $s = <<'EOF';
USAGE: aa-exec [OPTIONS] <prog> <args>

Confine <prog> with the specified PROFILE.

OPTIONS:
  -p PROFILE, --profile=PROFILE		PROFILE to confine <prog> with
  -n NAMESPACE, --namespace=NAMESPACE	NAMESPACE to confine <prog> in
  -f FILE, --file FILE		profile file to load
  -i, --immediate		change profile immediately instead of at exec
  -v, --verbose			show messages with stats
  -h, --help			display this help

EOF
    print $s;
}

use Getopt::Long;

GetOptions(
    'debug|d'        => \$opt_d,
    'help|h'         => \$opt_h,
    'profile|p=s'    => \$opt_p,
    'namespace|n=s'  => \$opt_n,
    'file|f=s'       => \$opt_f,
    'immediate|i'    => \$opt_i,
    'verbose|v'      => \$opt_v,
);

if ($opt_h) {
    usage();
    exit(0);
}

if ($opt_n || $opt_p) {
   my $test;
   my $prof;

   if ($opt_n) {
      $prof = ":$opt_n:";
   }

   $prof .= $opt_p;

   if ($opt_f) {
       system("apparmor_parser", "-r", "$opt_f") == 0
	   or _error("\'aborting could not load $opt_f\'");
   }

   if ($opt_i) {
       _verbose("aa_change_profile(\"$prof\")");
       $test = LibAppArmor::aa_change_profile($prof);
       _debug("$test = aa_change_profile(\"$prof\"); $!");
   } else {
       _verbose("aa_change_onexec(\"$prof\")");
       $test = LibAppArmor::aa_change_onexec($prof);
       _debug("$test = aa_change_onexec(\"$prof\"); $!");
   }

   if ($test != 0) {
       if ($!{ENOENT} || $!{EACCESS}) {
	   my $pre = ($opt_p) ? "profile" : "namespace";
	   _error("$pre \'$prof\' does not exist\n");
       } elsif ($!{EINVAL}) {
	   _error("AppArmor interface not available\n");
       } else {
	   _error("$!\n");
       }
   }
}

_verbose("exec @ARGV");
exec @ARGV;