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/* -*- c++ -*- */
/*
* Copyright 2013 Free Software Foundation, Inc.
*
* This file is part of GNU Radio
*
* GNU Radio 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.
*
* GNU Radio 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 GNU Radio; 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 <gr_io_signature.h>
#include "crc32_bb_impl.h"
#include <digital/crc32.h>
namespace gr {
namespace digital {
crc32_bb::sptr
crc32_bb::make(bool check, const std::string& lengthtagname)
{
return gnuradio::get_initial_sptr (new crc32_bb_impl(check, lengthtagname));
}
crc32_bb_impl::crc32_bb_impl(bool check, const std::string& lengthtagname)
: gr_tagged_stream_block("crc32_bb",
gr_make_io_signature(1, 1, sizeof (char)),
gr_make_io_signature(1, 1, sizeof (char)),
lengthtagname),
d_check(check)
{
set_tag_propagation_policy(TPP_DONT);
}
crc32_bb_impl::~crc32_bb_impl()
{
}
int
crc32_bb_impl::calculate_output_stream_length(const gr_vector_int &ninput_items)
{
if (d_check) {
return ninput_items[0] - 4;
} else {
return ninput_items[0] + 4;
}
}
int
crc32_bb_impl::work (int noutput_items,
gr_vector_int &ninput_items,
gr_vector_const_void_star &input_items,
gr_vector_void_star &output_items)
{
const unsigned char *in = (const unsigned char *) input_items[0];
unsigned char *out = (unsigned char *) output_items[0];
long packet_length = ninput_items[0];
int packet_size_diff = d_check ? -4 : 4;
unsigned int crc;
if (d_check) {
crc = gr::digital::crc32(in, packet_length-4);
if (crc != *(unsigned int *)(in+packet_length-4)) { // Drop package
return 0;
}
memcpy((void *) out, (const void *) in, packet_length-4);
} else {
crc = gr::digital::crc32(in, packet_length);
memcpy((void *) out, (const void *) in, packet_length);
memcpy((void *) (out + packet_length), &crc, 4); // FIXME big-endian/little-endian, this might be wrong
}
std::vector<gr_tag_t> tags;
get_tags_in_range(tags, 0, nitems_read(0), nitems_read(0)+packet_length);
for (unsigned i = 0; i < tags.size(); i++) {
tags[i].offset -= nitems_read(0);
if (d_check && tags[i].offset > packet_length+packet_size_diff) {
tags[i].offset = packet_length-5;
}
add_item_tag(0, nitems_written(0) + tags[i].offset,
tags[i].key,
tags[i].value);
}
return packet_length + packet_size_diff;
}
} /* namespace digital */
} /* namespace gr */
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