ndp.cpp

/**
 * \file ndp.cpp
 * \brief Packet reader using NDP library for high speed capture.
 * \author Tomas Benes <benesto@fit.cvut.cz>
 * \author Jiri Havranek <havraji6@fit.cvut.cz>
 * \date 2021
 */
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 *    may be used to endorse or promote products derived from this
 *    software without specific prior written permission.
 *
 * ALTERNATIVELY, provided that this notice is retained in full, this
 * product may be distributed under the terms of the GNU General Public
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 */


#include <config.h>
#ifdef HAVE_NDP

#include <cstdio>
#include <cstring>
#include <iostream>

#include "ndp.h"
#include "parser.h"

void packet_ndp_handler(parser_opt_t *opt, const struct ndp_packet *ndp_packet, const struct ndp_header *ndp_header)
{
   struct timeval ts;
   ts.tv_sec = ndp_header->timestamp_sec;
   ts.tv_usec = ndp_header->timestamp_nsec / 1000;

   parse_packet(opt, ts, ndp_packet->data, ndp_packet->data_length, ndp_packet->data_length);
}

NdpPacketReader::NdpPacketReader() : print_pcap_stats(false)
{
   processed = 0;
   parsed = 0;
}

NdpPacketReader::NdpPacketReader(const options_t &options)
{
   processed = 0;
   parsed = 0;
   print_pcap_stats = options.print_pcap_stats;
}

NdpPacketReader::~NdpPacketReader()
{
   this->close();
}

/**
 * \brief Open pcap file for reading.
 * \param [in] file Input file name.
 * \param [in] parse_every_pkt Try to parse every captured packet.
 * \return 0 on success, non 0 on failure + error_msg is filled with error message
 */
int NdpPacketReader::open_file(const string &file, bool parse_every_pkt)
{
   error_msg = "Pcap Not suported in this mode";
   return 1;
}

/**
 * \brief Initialize network interface for reading.
 * \param [in] interface Interface name.
 * \param [in] snaplen Snapshot length to be set on pcap handle.
 * \param [in] parse_every_pkt Try to parse every captured packet.
 * \return 0 on success, non 0 on failure + error_msg is filled with error message
 */
int NdpPacketReader::init_interface(const string &interface, int snaplen, bool parse_every_pkt)
{
   int res;
   res = ndpReader.init_interface(interface);
   error_msg = ndpReader.error_msg;

   parse_all = parse_every_pkt;
   return res;
}

/**
 * \brief Install BPF filter to pcap handle.
 * \param [in] filter_str String containing program.
 * \return 0 on success, non 0 on failure.
 */
int NdpPacketReader::set_filter(const string &filter_str)
{
   error_msg = "Filters not supported";
   return 1;
}

void NdpPacketReader::printStats()
{
   ndpReader.print_stats();
}

/**
 * \brief Close opened file or interface.
 */
void NdpPacketReader::close()
{
   ndpReader.close();
}

int NdpPacketReader::get_pkt(PacketBlock &packets)
{
   int ret = -1;
   if (print_pcap_stats) {
      //print_stats();
   }

   struct ndp_packet *ndp_packet;
   struct ndp_header *ndp_header;

   parser_opt_t opt = {&packets, false, parse_all, 0};
   size_t read_pkts = 0;
   for (unsigned i = 0; i < packets.size; i++) {
      ret = ndpReader.get_pkt(&ndp_packet, &ndp_header);
      if (ret == 0) {
         if (opt.pkts->cnt) {
            break;
         }
         return 3;
      } else if (ret < 0) {
         // Error occured.
         error_msg = ndpReader.error_msg;
         return ret;
      }
      read_pkts++;
      packet_ndp_handler(&opt, ndp_packet, ndp_header);
   }
   processed += read_pkts;
   parsed += opt.pkts->cnt;

   if (opt.pkts->cnt) {
      // Packets are valid and ready to be process by flow_cache.
      return 2;
   }
   return 1;
}

#endif /* HAVE_NDP */