/*
 * whatsapp.c
 *
 * This protocol inspector is adapted from
 * the nDPI WhatsApp dissector
 * (https://github.com/ntop/nDPI/blob/dev/src/lib/protocols/whatsapp.c)
 *
 * =========================================================================
 * 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>

static uint8_t whatsapp_sequence[] = {0x45, 0x44, 0x0,  0x01, 0x0,
                                      0x0,  0x02, 0x08, 0x0,  0x57,
                                      0x41, 0x02, 0x0,  0x0,  0x0};

uint8_t check_whatsapp(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 (flow_info_private->whatsapp_matched_sequence <
      sizeof(whatsapp_sequence)) {
    if (memcmp(app_data,
               &whatsapp_sequence[flow_info_private->whatsapp_matched_sequence],
               PFWL_MIN(sizeof(whatsapp_sequence) -
                            flow_info_private->whatsapp_matched_sequence,
                        data_length))) {
      return PFWL_PROTOCOL_NO_MATCHES;
    } else {
      flow_info_private->whatsapp_matched_sequence += data_length;
      return PFWL_PROTOCOL_MORE_DATA_NEEDED;
    }
  } else {
    return PFWL_PROTOCOL_MATCHES;
  }
}