/*
 * rtp_extraction.c
 *
 * Given a .pcap file, extracts the RTP Payload Time, Sequence Number, Timestamp
 *                                      and Syncronization Source Identifier
 *
 * Created on: 16/10/2018
 *
 * ===============================================================================
 * Copyright (c) 2018-2019, Michele Campus (michelecampus5@gmail.com)
 * Copyright (c) 2012-2019, 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/peafowl.h>
#include <pcap.h>
#include <net/ethernet.h>
#include <time.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <inttypes.h>
#include <assert.h>

int main(int argc, char** argv){

  if(argc != 2){
    fprintf(stderr, "Usage: %s pcap_file\n", argv[0]);
    return -1;
  }
  char* pcap_filename=argv[1];
  char errbuf[PCAP_ERRBUF_SIZE];

  pfwl_state_t* state = pfwl_init();
  pcap_t *handle = pcap_open_offline(pcap_filename, errbuf);

  if(handle == NULL){
    fprintf(stderr, "Couldn't open device %s: %s\n", pcap_filename, errbuf);
    return (2);
  }

  const u_char* packet;
  struct pcap_pkthdr header;

  // Payload Type
  pfwl_field_add_L7(state, PFWL_FIELDS_L7_RTP_PTYPE);
  // Sequence Number
  pfwl_field_add_L7(state, PFWL_FIELDS_L7_RTP_SEQNUM);
  // Timestamp
  pfwl_field_add_L7(state, PFWL_FIELDS_L7_RTP_TIMESTP);
  // Syncronization Source Identifier
  pfwl_field_add_L7(state, PFWL_FIELDS_L7_RTP_SSRC);

  pfwl_protocol_l2_t dlt = pfwl_convert_pcap_dlt(pcap_datalink(handle));

  while((packet = pcap_next(handle, &header)) != NULL){
    pfwl_dissection_info_t r;
    if(pfwl_dissect_from_L2(state, packet, header.caplen, time(NULL), dlt, &r) >= PFWL_STATUS_OK){
        int64_t extracted_value;
      if(r.l7.protocol == PFWL_PROTO_L7_RTP &&
         !pfwl_field_number_get(r.l7.protocol_fields, PFWL_FIELDS_L7_RTP_PTYPE, &extracted_value)){
          printf("Payload Type detected: %li\n", extracted_value);
      }
      if(r.l7.protocol == PFWL_PROTO_L7_RTP &&
         !pfwl_field_number_get(r.l7.protocol_fields, PFWL_FIELDS_L7_RTP_SEQNUM, &extracted_value)){
          printf("Sequence Number detected: %li\n", extracted_value);
      }
      if(r.l7.protocol == PFWL_PROTO_L7_RTP &&
         !pfwl_field_number_get(r.l7.protocol_fields, PFWL_FIELDS_L7_RTP_TIMESTP, &extracted_value)){
          printf("Timestamp detected: %li\n", extracted_value);
      }
      if(r.l7.protocol == PFWL_PROTO_L7_RTP &&
         !pfwl_field_number_get(r.l7.protocol_fields, PFWL_FIELDS_L7_RTP_SSRC, &extracted_value)){
          printf("Syncronization Source Identifier detected: %li\n", extracted_value);
      }
    }
  }
  return 0;
}