#!/usr/bin/perl -w
#
# WardenClientReceive.pm
#
# Copyright (C) 2011 Cesnet z.s.p.o
# Author(s): 	Tomas PLESNIK 	<plesnik@ics.muni.cz>
#		Jan SOUKAL	<soukal@ics.muni.cz>
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in
#    the documentation and/or other materials provided with the
#    distribution.
# 3. Neither the name of the Cesnet z.s.p.o nor the names of its
#    contributors may be used to endorse or promote products derived from
#    this software without specific prior written permission.
#
# This software is provided ``as is'', and any express or implied
# warranties, including, but not limited to, the implied warranties of
# merchantability and fitness for a particular purpose are disclaimed.
# In no event shall the Cesnet z.s.p.o or contributors be liable for
# any direct, indirect, incidental, special, exemplary, or consequential
# damages (including, but not limited to, procurement of substitute
# goods or services; loss of use, data, or profits; or business
# interruption) however caused and on any theory of liability, whether
# in contract, strict liability, or tort (including negligence or
# otherwise) arising in any way out of the use of this software, even
# if advised of the possibility of such damage.

package WardenClientReceive;

use strict;
use SOAP::Lite;
use IO::Socket::SSL qw(debug1);
use SOAP::Transport::TCP;
use FindBin;

our $VERSION = 100;

#-------------------------------------------------------------------------------
# errMsg - print error message and die
#-------------------------------------------------------------------------------
sub errMsg
{
  my $msg = shift;
  die($msg . "\n");
} # End of errMsg


#-------------------------------------------------------------------------------
# c2s - connect to server, send request and receive response
#-------------------------------------------------------------------------------
sub c2s 
{
  my $uri		= shift;
  my $ssl_key_file	= shift;
  my $ssl_cert_file	= shift;
  my $ssl_ca_file	= shift;
  my $method		= shift;
  my $data		= shift;

  my $client;
  my ($server, $port, $service) = $uri =~ /https:\/\/(.+)\:(\d+)\/(.+)/;
  if (!($client = SOAP::Transport::TCP::Client->new(
    PeerAddr            => $server,
    PeerPort            => $port,
    Proto               => 'tcp',
    SSL_use_cert        => 1,
    SSL_verify_mode     => 0x02,
    SSL_key_file        => $ssl_key_file,
    SSL_cert_file       => $ssl_cert_file,
    SSL_ca_file         => $ssl_ca_file,
  ))) {errMsg("Sorry, unable to create socket: " . &SOAP::Transport::TCP::Client::errstr)}

  # setting of URI and serialize SOAP envelope and data object
  my $soap = SOAP::Lite->uri($uri);
  my $envelope;
  if (!defined $data) {
    $envelope = $soap->serializer->envelope(method => $method);
  } else {
    $envelope = $soap->serializer->envelope(method => $method, $data);
  }

  # setting of TCP URI and send serialized SOAP envelope and data
  my $tcp_uri = "tcp://$server:$port/$service";
  my $result = $client->send_receive(envelope => $envelope, endpoint => $tcp_uri);

  # check server response
  if (!defined $result) {
    errMsg("Error: server returned empty response. Probably problem with used SSL ceritificates.");
  } else {
    # deserialized response from server -> create SOAP envelope and data object
    my $response = $soap->deserializer->deserialize($result);
    # check SOAP fault status
    $response->fault ? errMsg("Server sent error message:: " . $response->faultstring) : return $response;
  }
}


#-------------------------------------------------------------------------------
# getNewEvents - get new events from warden server greater than last received ID
#-------------------------------------------------------------------------------
sub getNewEvents
{
  my $warden_path = shift;
  my $requested_type = shift;

  my $vardir = $warden_path . "/var/";
  my $etcdir = $warden_path . "/etc/";
  my $libdir = $warden_path . "/lib/";

  # read the config file
  require $libdir .  "WardenClientConf.pm";
  my $conf_file = $etcdir . "warden-client.conf";
  my ($uri, $ssl_key_file, $ssl_cert_file, $ssl_ca_file) = WardenClientConf::loadConf($conf_file);

  # set name of ID file for each client aplication 
  my $caller_name = $FindBin::Script;
  my $id_file = $vardir . $caller_name . ".id";

  #-----------------------------------------------------------------------------
  # get last ID from ID file (if exist) or
  # get last ID from warden server DB and save it into ID file
  my $last_id;
  if (-e $id_file) {
    open(ID, "< $id_file") || errMsg("Cannot open ID file $id_file: $!");
    foreach(<ID>) {
      $last_id = $_;
    }
    close ID;
  } else {
    my $response = c2s($uri, $ssl_key_file, $ssl_cert_file, $ssl_ca_file, "getLastId");
    $last_id = $response->result;
    open(ID, "> $id_file") || die ("Cannot open ID file $id_file: $!");
    print ID $last_id;
    close ID;
  }

  #-----------------------------------------------------------------------------
  # get new events from warden server DB based on gathered last ID 

  # create SOAP data obejct
  my $request_data = SOAP::Data->name(request => \SOAP::Data->value(
    SOAP::Data->name(REQUESTED_TYPE => $requested_type),
    SOAP::Data->name(LAST_ID => $last_id)
  ));
  my $response = c2s($uri, $ssl_key_file, $ssl_cert_file, $ssl_ca_file, "getNewEvents", $request_data);

  # match getNewEvents functions response
  $response->match('/Envelope/Body/getNewEventsResponse/');
  my ($id, $hostname, $service, $detected, $type, $source_type, $source, $target_proto, $target_port, $attack_scale, $note, $priority, $timeout);
  my @events;

  # parse returned SOAP data object
  my $i = 1;
  my $response_data = $response->valueof("[$i]");
  while (defined $response_data) {
    my @event;

    # parse items of one event
    $id			= $response_data->{'ID'};
    $hostname		= $response_data->{'HOSTNAME'};
    $service		= $response_data->{'SERVICE'};
    $detected 		= $response_data->{'DETECTED'};
    $type		= $response_data->{'TYPE'};
    $source_type	= $response_data->{'SOURCE_TYPE'};
    $source		= $response_data->{'SOURCE'};
    $target_proto	= $response_data->{'TARGET_PROTO'};
    $target_port	= $response_data->{'TARGET_PORT'};
    $attack_scale	= $response_data->{'ATTACK_SCALE'};
    $note		= $response_data->{'NOTE'};
    $priority		= $response_data->{'PRIORITY'};
    $timeout		= $response_data->{'TIMEOUT'};

    # push new event from warden server into @events which is returned
    @event = ("$id", "$hostname", "$service", "$detected", "$type", "$source_type", "$source", "$target_proto", "$target_port", "$attack_scale", "$note", "$priority", "$timeout");
    push (@events, \@event);

    # set maximum received ID from current batch
    if ($id > $last_id) {
	    $last_id = $id;
    }

    # go to the next received event
    $i++;
    $response_data = $response->valueof("[$i]");
  }

  # write last return ID
  if (defined $last_id) {		# must be defined for first check ID
    open(ID, "> $id_file") || die ("Cannot open ID file $id_file: $!");
    print ID $last_id;
    close ID;
  }

  # return event array of arrays 
  return @events;
} # End of getNewEvents

1;