/*
 * ciscovpn.c
 * Copyright (C) 2013 by Remy Mudingay <mudingay@ill.fr>
 *
 */

#include "ndpi_protocol_ids.h"

#define NDPI_CURRENT_PROTO NDPI_PROTOCOL_CISCOVPN

#include "ndpi_api.h"


static void ndpi_int_ciscovpn_add_connection(struct ndpi_detection_module_struct *ndpi_struct, struct ndpi_flow_struct *flow)
{
  ndpi_set_detected_protocol(ndpi_struct, flow, NDPI_PROTOCOL_CISCOVPN, NDPI_PROTOCOL_UNKNOWN);
}

void ndpi_search_ciscovpn(struct ndpi_detection_module_struct *ndpi_struct, struct ndpi_flow_struct *flow)
{
  struct ndpi_packet_struct *packet = &flow->packet;
  u_int16_t udport = 0, usport = 0;
  u_int16_t tdport = 0, tsport = 0;


  NDPI_LOG_DBG(ndpi_struct, "search CISCOVPN\n");

  if(packet->tcp != NULL) {
    tsport = ntohs(packet->tcp->source), tdport = ntohs(packet->tcp->dest);
    NDPI_LOG_DBG2(ndpi_struct, "calculated CISCOVPN over tcp ports\n");
  }
  if(packet->udp != NULL) {
    usport = ntohs(packet->udp->source), udport = ntohs(packet->udp->dest);
    NDPI_LOG_DBG2(ndpi_struct, "calculated CISCOVPN over udp ports\n");
  }

  if((tdport == 10000 && tsport == 10000) ||
     ((tsport == 443 || tdport == 443) &&
      (packet->payload[0] == 0x17 &&
       packet->payload[1] == 0x01 &&
       packet->payload[2] == 0x00 &&
       packet->payload[3] == 0x00)
      )
     )

    {
      /* This is a good query  17010000*/
      NDPI_LOG_INFO(ndpi_struct, "found CISCOVPN\n");
      ndpi_int_ciscovpn_add_connection(ndpi_struct, flow);
      return;
    }
  else if(((tsport == 443 || tdport == 443) ||
          (tsport == 80 || tdport == 80)) &&
          ((packet->payload[0] == 0x17 &&
           packet->payload[1] == 0x03 &&
           packet->payload[2] == 0x03 &&
           packet->payload[3] == 0x00 &&
           packet->payload[4] == 0x3A)))
    {
      /* TLS signature of Cisco AnyConnect 0X170303003A */
      NDPI_LOG_INFO(ndpi_struct, "found CISCO Anyconnect VPN\n");
      ndpi_int_ciscovpn_add_connection(ndpi_struct, flow);
      return;
    }
  else if(((tsport == 8009 || tdport == 8009) ||
          (tsport == 8008 || tdport == 8008)) &&
          ((packet->payload[0] == 0x17 &&
           packet->payload[1] == 0x03 &&
           packet->payload[2] == 0x03 &&
           packet->payload[3] == 0x00 &&
           packet->payload[4] == 0x69)))
    {
      /* TCP signature of Cisco AnyConnect 0X1703030069 */
      NDPI_LOG_INFO(ndpi_struct, "found CISCO Anyconnect VPN\n");
      ndpi_int_ciscovpn_add_connection(ndpi_struct, flow);
      return;
    }
  else if(
	  (
	   (usport == 10000 && udport == 10000)
	   &&
	   (packet->payload[0] == 0xfe &&
	    packet->payload[1] == 0x57 &&
	    packet->payload[2] == 0x7e &&
	    packet->payload[3] == 0x2b)
	   )
	  )
    {


      /* This is a good query  fe577e2b */
      NDPI_LOG_INFO(ndpi_struct, "found CISCOVPN\n");
      ndpi_int_ciscovpn_add_connection(ndpi_struct, flow);
    } else {
    NDPI_EXCLUDE_PROTO(ndpi_struct, flow);
  }

}


void init_ciscovpn_dissector(struct ndpi_detection_module_struct *ndpi_struct, u_int32_t *id, NDPI_PROTOCOL_BITMASK *detection_bitmask)
{
  ndpi_set_bitmask_protocol_detection("CiscoVPN", ndpi_struct, detection_bitmask, *id,
				      NDPI_PROTOCOL_CISCOVPN,
				      ndpi_search_ciscovpn,
				      NDPI_SELECTION_BITMASK_PROTOCOL_TCP_OR_UDP_WITH_PAYLOAD,
				      SAVE_DETECTION_BITMASK_AS_UNKNOWN,
				      ADD_TO_DETECTION_BITMASK);
  *id += 1;
}