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/* -*- c++ -*- */
/*
* Copyright 2009 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 this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <vrt/expanded_header.h>
#include <gruel/inet.h>
//#include <stdio.h>
namespace vrt {
// lookup tables indexed by packet type
unsigned char expanded_header::s_if_data[16] = {
1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};
unsigned char expanded_header::s_ext_data[16] = {
0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};
unsigned char expanded_header::s_data[16] = {
1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};
unsigned char expanded_header::s_context[16] = {
0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};
unsigned char expanded_header::s_stream_id[16] = {
0, 1, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};
// dispatch codeword bits
static const int HAS_STREAM_ID = 1 << 0;
static const int HAS_CLASS_ID = 1 << 1;
static const int HAS_INTEGER_SECS = 1 << 2;
static const int HAS_FRACTIONAL_SECS = 1 << 3;
static const int HAS_TRAILER = 1 << 4;
#include "expanded_header_cw_tables.h"
static int
compute_codeword(const expanded_header &h)
{
int cw = 0;
if (h.stream_id_p()) cw |= HAS_STREAM_ID;
if (h.class_id_p()) cw |= HAS_CLASS_ID;
if (h.integer_secs_p()) cw |= HAS_INTEGER_SECS;
if (h.fractional_secs_p()) cw |= HAS_FRACTIONAL_SECS;
if (h.trailer_p()) cw |= HAS_TRAILER;
return cw;
}
bool
expanded_header::parse(const uint32_t *packet, // in
size_t n32_bit_words_packet, // in
expanded_header *h, // out
const uint32_t **payload, // out
size_t *n32_bit_words_payload) // out
{
size_t len = n32_bit_words_packet;
const uint32_t *p = packet;
*payload = 0;
*n32_bit_words_payload = 0;
// printf("parse: n32_bit_words_packet = %zd\n", n32_bit_words_packet);
if (len < 1){ // must have at least the header word
h->header = 0;
return false;
}
h->header = ntohl(p[0]);
if (h->pkt_size() > len)
return false; // VRT header says packet is bigger than what we've got
len = h->pkt_size(); // valid length of packet
int cw = compute_codeword(*h);
if (cw_header_len(cw) + cw_trailer_len(cw) > len)
return false; // negative payload len
*payload = p + cw_header_len(cw);
*n32_bit_words_payload = len - (cw_header_len(cw) + cw_trailer_len(cw));
// printf("parse: hdr = 0x%08x, cw = 0x%02x, cw_header_len(cw) = %d, cw_trailer_len(cw) = %d\n",
// h->header, cw, cw_header_len(cw), cw_trailer_len(cw));
switch (cw & 0x1f){
#include "expanded_header_switch_body.h"
}
/* is this a if context packet? */
if (h->if_context_p()){
*payload = p;
*n32_bit_words_payload = n32_bit_words_packet;
}
return true;
}
}; // vrt
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