#   MailScanner - SMTP E-Mail Virus Scanner
#   Copyright (C) 2002  Julian Field
#
#   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
#

#   07/23/2002
#   James A. Pattie (james@pcxperience.com) - updated to only have the
#   options needed for virus scanning configuration.

# Read the configuration file and set globals accordingly.

use strict;
package Config;

my $prefix = '/etc/dansguardian';

# Default values
$Config::Debugging            = 0;
$Config::Sweep                = "/usr/local/sophos/bin/sophoswrapper";
$Config::PidFile              = "/var/run/virus.pid";
$Config::DefaultConfig        = "$prefix/virusscanner.conf";
$Config::QuarantineAction     = 'store';
$Config::LocalPostmaster      = 'postmaster';
$Config::QuarantineDir        = "/var/www/html/dgvirus/quarantine";
$Config::VirusScanner         = 'sophos';
$Config::LockType             = '';
$Config::SweepTimeout         = 300;
$Config::CodeStatus                 = 'supported';
$Config::LockDir                    = '/tmp';
$Config::SyslogFacility             = 'user';
$Config::MailDomain                 = 'your.domain.com';
$Config::MailServer                 = '127.0.0.1';
$Config::MailType                   = 'text/plain';
$Config::DownloadDir                = '/tmp/dgvirus';
$Config::StatusGroupedBy             = 'uname';

sub ReadConfig {
  my($Config) = @_;
  my($key, $value, $whole);
  local(*CONF);

  $Config = $Config::DefaultConfig unless defined $Config;

  open(CONF, $Config)
    or Log::DieLog("Could not open config file $Config, %s", $!);
  while(<CONF>) {
    chomp;
    s/#.*$//;     # Trim comments
    s/^\s*//g;    # Trim leading space
    # Extract everything after the =\s* for inline signatures
    /^[^=]*=\s*(.*)$/;
    $whole = $1;
    s/\s*$//g;    # Trim trailing space
    next if /^$/; # Ignore comments

# This was
#    ($key, $value) = split(/\s*=\s*/, $_, 2);
# The following should be equivalent but with untainting
# (we trust the admin to put sensible things in the config file).
# -- nwp, 14/01/02
    /^(.*?)\s*=\s*(.*)$/;
    ($key,$value) = ($1,$2);

    $key = lc($key);
    $key =~ s/[^a-z]//g; # Delete everything except letters
    $Config::PidFile               = $value if $key =~ /^pid/;
    $Config::Sweep                 = $value if $key =~ /^sweep/;
    $Config::LocalPostmaster       = $value if $key =~ /^localpostmaster/;
    $Config::Debugging             = $value if $key =~ /^debug/;
    $Config::QuarantineAction      = $value if $key =~ /^action/;
    $Config::QuarantineDir         = $value if $key =~ /^quarantinedir/;
    $Config::VirusScanner          = lc($value) if $key =~ /^virusscanner$/i;
    $Config::LockType              = lc($value) if $key =~ /^locktype/i;
    $Config::SweepTimeout          = $value if $key =~ /^virusscannertimeout/i;
    $Config::CodeStatus            = $value if $key =~ /^minimumcodestatus/i;
    $Config::LockDir               = $value if $key =~ /^lockfiledir/i;
    $Config::SyslogFacility        = $value if $key =~ /^logfacility$/i;
    $Config::MailDomain            = $value if $key =~ /^maildomain$/i;
    $Config::MailServer            = $value if $key =~ /^mailserver$/i;
    $Config::MailType              = $value if $key =~ /^mailtype$/i;
    $Config::DownloadDir           = $value if $key =~ /^downloaddir$/i;
    $Config::StatusGroupedBy       = $value if $key =~ /^statusinfogroupedby$/i;

  }
  close CONF;

  # Start logging here so we can set the log facility first
  Log::Start($Config::MailScannerProcessName, $Config::SyslogFacility);
  Log::InfoLog("Virus Scanner $Config::DGVirusVersion in DansGuardian $Config::DGVersion from MailScanner $Config::MailScannerVersion starting.");

  # Sanitise values of QuarantineAction
  $Config::QuarantineAction = 'store'
    if $Config::QuarantineAction =~ /quar|keep|stor|save/i;
  $Config::QuarantineAction = 'delete'
    if $Config::QuarantineAction =~ /dele|wipe/i;

  # make sure we have a valid MailType
  Log::DieLog("MailType = '$Config::MailType' is invalid!  Needs to be 'text/plain' or 'text/html'.") if ($Config::MailType !~ /^(text\/(plain|html))$/);

  # make sure we have a valid MailDomain value
  Log::DieLog("MailDomain = '$Config::MailDomain' is invalid!  You need to specify your own mail domain!") if ($Config::MailDomain eq "your.domain.com");

  # make sure we have a valid StatusGroupedBy value
  Log::DieLog("Status Info Grouped By = '$Config::StatusGroupedBy' is invalid!  Needs to be 'uname' or 'ip'.") if ($Config::StatusGroupedBy !~ /^(uname|ip)$/);

  # Remove any trailing slashes from the directory names, they will cause
  # trouble later if left in.
  $Config::QuarantineDir =~ s/\/$//;
  $Config::LockDir       =~ s/\/$//;
  $Config::DownloadDir   =~ s/\/$//;

  # Check to ensure all the directories and files we need actually exist
  DirExists($Config::QuarantineDir) if ($Config::QuarantineAction eq "store");
  DirExists($Config::LockDir);

  # Check that the script at the start of the "Sweep" command exists
  my($command);
  $command = (split(/[,\s]/, $Config::Sweep, 2))[0];
  if ($command eq "none")
  {
    DieLog("You must specify a virus engine to work with other than none!");
  }
  FileReadable($command);

}

#
# Check a configuration file exists and is readable.
# Produce an error if it is not.
#
sub FileReadable {
  my($name) = @_;
  return 1 unless $name;
  return 1 if -r $name;
  Log::DieLog("Configuration file $name could not be opened for reading!");
}

# Check a directory exists and is writeable.
# Produce an error if it is not.
#
sub DirExists {
  my($name) = @_;
  return 1 unless $name;
  return 1 if -d $name;
  Log::DieLog("Directory $name does not exist!");
}

# Check two files/directories are on the same partition.
# Produce an error if it is not.
# Can't do this here as it breaks "require" by changing directory.

#
# Set a Config variable to 0 or 1 depending on its current contents
#
sub ZeroOrOne {
  my($current) = @_;
  return 1 if $current =~ /yes|true|on|1/i;
  return 0;
}

1;