/*
 * bgp.c
 *
 * Created on: 19/09/2012
 * =========================================================================
 * Copyright (c) 2016-2019 Daniele De Sensi (d.desensi.software@gmail.com)
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 * =========================================================================
 */
#include <peafowl/inspectors/inspectors.h>
#include <peafowl/peafowl.h>

// TODO: We could use this https://github.com/deepfield/MRT/tree/master/src/lib/bgp_proto for a complete parsing

uint8_t check_bgp(pfwl_state_t *state, const unsigned char *app_data,
                  size_t data_length, pfwl_dissection_info_t *pkt_info,
                  pfwl_flow_info_private_t *flow_info_private) {
  if (data_length > 18) {
    if (get_u64(app_data, 0) == 0xffffffffffffffffULL &&
        get_u64(app_data, 8) == 0xffffffffffffffffULL &&
        ntohs(get_u16(app_data, 16)) <= data_length &&
        (pkt_info->l4.port_dst == port_bgp ||
         pkt_info->l4.port_src == port_bgp) &&
        app_data[18] < 5) {
      return PFWL_PROTOCOL_MATCHES;
    } else
      return PFWL_PROTOCOL_NO_MATCHES;
  } else
    return PFWL_PROTOCOL_MORE_DATA_NEEDED;
}