op25/op25/gr-op25/lib/pcap_source_b_impl.cc

118 lines
3.3 KiB
C++

/* -*- c++ -*- */
/*
* Copyright 2010,2011 Steve Glass
*
* This file is part of OP25.
*
* This is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3, or (at your option)
* any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this software; see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street,
* Boston, MA 02110-1301, USA.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <gnuradio/io_signature.h>
#include "pcap_source_b_impl.h"
#define PCAP_DONT_INCLUDE_PCAP_BPF_H
#include <pcap/pcap.h>
using namespace std;
namespace gr {
namespace op25 {
pcap_source_b::sptr
pcap_source_b::make(const char *path, float delay)
{
return gnuradio::get_initial_sptr
(new pcap_source_b_impl(path, delay));
}
/*
* The private constructor
*/
pcap_source_b_impl::pcap_source_b_impl(const char *path, float delay)
: gr::sync_block("pcap_source_b",
gr::io_signature::make(0, 0, 0),
gr::io_signature::make(1, 1, sizeof(uint8_t))),
loc_(0),
octets_(/* delay * 1200, 0 */)
{
char err[PCAP_ERRBUF_SIZE];
pcap_t *pcap = pcap_open_offline(path, err);
if(pcap) {
struct pcap_pkthdr hdr;
for(const uint8_t *octets; octets = pcap_next(pcap, &hdr);) {
const size_t ETHERNET_SZ = 14;
const size_t IP_SZ = 20;
const size_t UDP_SZ = 8;
const size_t P25CAI_OFS = ETHERNET_SZ + IP_SZ + UDP_SZ;
if(P25CAI_OFS < hdr.caplen) {
const size_t FRAME_SZ = hdr.caplen - P25CAI_OFS;
#if 0
// push some zero octets to separate frames
const size_t SILENCE_OCTETS = 48;
octets_.resize(octets_.size() + SILENCE_OCTETS, 0);
#endif
// push octets from frame payload into local buffer
octets_.reserve(octets_.size() + hdr.caplen - P25CAI_OFS);
for(size_t i = 0; i < FRAME_SZ; ++i) {
octets_.push_back(octets[P25CAI_OFS + i]);
}
}
}
pcap_close(pcap);
} else {
cerr << "error: failed to open " << path;
cerr << " (" << err << ")" << endl;
exit(EXIT_FAILURE);
}
}
/*
* Our virtual destructor.
*/
pcap_source_b_impl::~pcap_source_b_impl()
{
}
int
pcap_source_b_impl::work(int noutput_items,
gr_vector_const_void_star &input_items,
gr_vector_void_star &output_items)
{
try {
const size_t OCTETS_AVAIL = octets_.size();
uint8_t *out = reinterpret_cast<uint8_t*>(output_items[0]);
const int OCTETS_REQD = static_cast<size_t>(noutput_items);
for(int i = 0; i < OCTETS_REQD; ++i) {
out[i] = octets_[loc_++];
loc_ %= OCTETS_AVAIL;
}
return OCTETS_REQD;
} catch(const exception& x) {
cerr << x.what() << endl;
exit(EXIT_FAILURE);
} catch(...) {
cerr << "unhandled exception" << endl;
exit(EXIT_FAILURE);
}
}
} /* namespace op25 */
} /* namespace gr */