diff options
Diffstat (limited to 'vrt/lib/expanded_header.cc')
| -rw-r--r-- | vrt/lib/expanded_header.cc | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/vrt/lib/expanded_header.cc b/vrt/lib/expanded_header.cc new file mode 100644 index 000000000..8b22fb925 --- /dev/null +++ b/vrt/lib/expanded_header.cc @@ -0,0 +1,135 @@ +/* -*- 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; + + 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; + } + + void expanded_header::unparse(const expanded_header *h, // in + size_t n32_bit_words_payload, // in + uint32_t *header, // out + size_t *n32_bit_words_header, // out + uint32_t *trailer, // out + size_t *n32_bit_words_trailer){// out + int cw = compute_codeword(*h); + //fills in the header (except word0), header length, trailer, trailer length + switch (cw & 0x1f){ +#include "expanded_header_unparse_switch_body.h" + } + //fill in the header word 0 with the calculated length + size_t n32_bit_words_packet = *n32_bit_words_header + n32_bit_words_payload + *n32_bit_words_trailer; + header[0] = htonl((h->header & ~VRTH_PKT_SIZE_MASK) | (n32_bit_words_packet & VRTH_PKT_SIZE_MASK)); + } + + 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 n32_bit_words_header = 0; + size_t n32_bit_words_trailer = 0; + 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); + switch (cw & 0x1f){ +#include "expanded_header_parse_switch_body.h" + } + + if (n32_bit_words_header + n32_bit_words_trailer > len) + return false; // negative payload len + + *payload = p + n32_bit_words_header; + *n32_bit_words_payload = len - (n32_bit_words_header + n32_bit_words_trailer); + + // printf("parse: hdr = 0x%08x, cw = 0x%02x, n32_bit_words_header = %d, n32_bit_words_trailer = %d\n", + // h->header, cw, n32_bit_words_header, n32_bit_words_trailer); + + return true; + } + + +}; // vrt |