#!/usr/bin/perl

#
# AntiVir updater. Original code by Julian Field. Timeout code by
# Alessandro Bianchi.
#

use Sys::Syslog;

$PackageDir = shift || "/usr/lib/AntiVir";

$AntiVirCommand = "$PackageDir/antivir";
$AntiVirUpdateCommand = "$AntiVirCommand --update";

$LockFile = "/tmp/AntiVirBusy.lock";

$LOCK_SH = 1;
$LOCK_EX = 2;
$LOCK_NB = 4;
$LOCK_UN = 8;

eval { Sys::Syslog::setlogsock('unix'); }; # This may fail!
Sys::Syslog::openlog("AntiVir-autoupdate", 'pid, nowait', 'mail');

BailOut("Installation dir \"$PackageDir\" does not exist!")
  unless $PackageDir ne "" && -d $PackageDir;

if (-x "$AntiVirCommand") {
  # Timeout prevention
  $SIG{ALRM} = sub { die "timeout"};

  &LockAntiVir();
  eval {
    alarm 300;
    $retval=system($AntiVirUpdateCommand)>>8;
    &UnlockAntiVir();
    alarm 0;
  };

  if ($@) {
    if ($@ =~ /timeout/) {
      # We timed out!
      &UnlockAntiVir();
      Sys::Syslog::syslog('err', "WARNING AntiVir update timed out");
      alarm 0;
    }
  } else {
    alarm 0;
    Sys::Syslog::syslog('info', "AntiVir update finished");
  }
} else {
  Sys::Syslog::syslog('err', "AntiVir updater $AntiVirUpdateCommand cannot be run");
}

Sys::Syslog::closelog();
exit 0;

sub BailOut {
	Sys::Syslog::syslog('err', @_);
	Sys::Syslog::closelog();
	warn "@_, $!";
	exit 1;
}

sub LockAntiVir {
	open(LOCK, ">$LockFile") or return;
	flock(LOCK, $LOCK_EX);
	print LOCK "Locked for updating AntiVir definitions by $$\n";
}

sub UnlockAntiVir {
	print LOCK "Unlocked after updating AntiVir definitions by $$\n";
	unlink $LockFile;
	flock(LOCK, $LOCK_UN);
	close LOCK;
}