#!/usr/bin/perl
#
#   MailScanner - SMTP E-Mail Virus Scanner
#   Copyright (C) 2002  Julian Field
#
#   $Id: f-prot-6-autoupdate 1958 2003-09-26 08:42:17Z jkf $
#
#   This program is free software; you can redistribute it and/or modify
#   it under the terms of the GNU General Public License as published by
#   the Free Software Foundation; either version 2 of the License, or
#   (at your option) any later version.
#
#   This program is distributed in the hope that it will be useful,
#   but WITHOUT ANY WARRANTY; without even the implied warranty of
#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#   GNU General Public License for more details.
#
#   You should have received a copy of the GNU General Public License
#   along with this program; if not, write to the Free Software
#   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#
#   The author, Julian Field, can be contacted by email at
#      Jules@JulianField.net
#   or by paper mail at
#      Julian Field
#      Dept of Electronics & Computer Science
#      University of Southampton
#      Southampton
#      SO17 1BJ
#      United Kingdom
#

use Sys::Syslog;
use FileHandle;
use IO::File;
# Stop syslogd from needing external access (or -r)
eval { Sys::Syslog::setlogsock('unix'); };

####################################
#
# You can set your HTTP proxy server / web-cache here if you want to,
# otherwise you will have to set it in the environment or wget's
# startup file.
# If you don't want to specify it here, comment out the next line.
#
#$Proxy  = 'www-cache.soton.ac.uk:3128';
#$ProxyUsername = '';
#$ProxyPassword = '';
#
####################################

$LockFile = "/tmp/FProt6Busy.lock";
$PackageDir = shift || "/opt/f-prot";

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

$FProtIsLocked = 0;

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

#
# Download update information from the update server
#
$command = "$PackageDir/fpupdate";
$command .= " --proxy $Proxy --proxy-username $ProxyUsername --proxy-password $ProxyPassword" if $Proxy;
my $logfile = "/tmp/f-prot-6-update-$$";
$command .= " >$logfile 2>&1";

#
# Lock out all other users of F-Prot until update is complete.
#
# Timeout prevention
$SIG{ALRM} = sub { die "timeout"};

#
# Now read and compare checksums of the files on the update server and
# the local def files.
#
eval {
  alarm 600;
  &LockFProt();
  unlink "/tmp/fpavdef.lock";
  print STDERR "About to $command\n";
  $result = system($command);
  print STDERR "Update completed.\n";
  # Clean up and exit.
  alarm 0;
};

if ($@) {
  if ($@ =~ /timeout/) {
    # We timed out!
    alarm 0;
    Sys::Syslog::openlog("F-Prot-6 autoupdate", 'pid, nowait', 'mail');
    Sys::Syslog::syslog('info', "F-Prot-6 auto-updater failed and timed out!");
  }
} else {
  alarm 0;
  Sys::Syslog::openlog("F-Prot-6 autoupdate", 'pid, nowait', 'mail');
  my $fh;
  if (defined($fh = new FileHandle("< $logfile"))) {
    my $in = <$fh>;
    if ($in =~ /^Downloading update/) {
      Sys::Syslog::syslog('info', "F-Prot-6 updated");
    } else {
      Sys::Syslog::syslog('info', "F-Prot-6 did not need updating");
    }
  } else {
    Sys::Syslog::syslog('info', "F-Prot-6 auto-updater completed abnormally!");
  }
}

# Clean up and exit nicely
&UnlockFProt();
unlink $logfile;
Sys::Syslog::closelog();
exit 0;

#########################################################################

sub BailOut {
	&UnlockFProt();
	Sys::Syslog::openlog("F-Prot-6 autoupdate", 'pid, nowait', 'mail');
	Sys::Syslog::syslog('err', @_);
	Sys::Syslog::closelog();
	warn "@_\n";
	chdir $PackageDir or die "Cannot cd $PackageDir, $!";
	exit 1;
}

sub LockFProt {
	open(LOCK, ">$LockFile") or return;
	flock(LOCK, $LOCK_EX);
	print LOCK "Locked for updating F-Prot-6 signature files by $$\n";
	$FProtIsLocked = 1;
}

sub UnlockFProt {
	return unless $FProtIsLocked;
	print LOCK "Unlocked after updating F-Prot-6 signature files by $$\n";
	unlink $LockFile;
	flock(LOCK, $LOCK_UN);
	close LOCK;
}