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wireshark/epan/dissectors/packet-rmt-fec.c
Michael Mann 9b7fb8a811 Create the ability to have packet scoped "proto" data. Bug 9470 (https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=9470) 
I'm not sold on the name or module the proto_data functions live in, but I believe the function arguments are solid and gives us the most flexibility for the future.  And search/replace of a function name is easy enough to do.

The big driving force for getting this in sooner rather than later is the saved memory on ethernet packets (and IP packets soon), that used to have file_scope() proto data when all it needed was packet_scope() data (technically packet_info->pool scoped), strictly for Decode As.

All dissectors that use p_add_proto_data() only for Decode As functionality have been converted to using packet_scope().  All other dissectors were converted to using file_scope() which was the original scope for "proto" data.

svn path=/trunk/; revision=53520
2013-11-23 02:20:13 +00:00

342 lines
12 KiB
C
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/* packet-rmt-fec.c
* Reliable Multicast Transport (RMT)
* FEC Building Block dissector
* Copyright 2005, Stefano Pettini <spettini@users.sourceforge.net>
*
* Forward Error Correction (ALC):
* -------------------------------
*
* The goal of the FEC building block is to describe functionality
* directly related to FEC codes that is common to all reliable content
* delivery IP multicast protocols, and to leave out any additional
* functionality that is specific to particular protocols.
*
* References:
* RFC 3452, Forward Error Correction Building Block
* RFC 3695, Compact Forward Error Correction (FEC) Schemes
* Simple XOR, Reed-Solomon, and Parity Check Matrix-based FEC Schemes draft-peltotalo-rmt-bb-fec-supp-xor-pcm-rs-00
* IANA RMT FEC parameters (http://www.iana.org/assignments/rmt-fec-parameters)
*
* $Id$
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998 Gerald Combs
*
* This program 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 2
* of the License, or (at your option) any later version.
*
* This program 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.
*/
#include "config.h"
#include <glib.h>
#include <epan/packet.h>
#include <epan/prefs.h>
#include <epan/expert.h>
#include <epan/wmem/wmem.h>
#include "packet-rmt-common.h"
static int proto_rmt_fec = -1;
static int hf_encoding_id = -1;
static int hf_instance_id = -1;
static int hf_sbn = -1;
static int hf_sbn_with_mask = -1;
static int hf_sbl = -1;
static int hf_esi = -1;
static int hf_esi_with_mask = -1;
static int hf_fti_transfer_length = -1;
static int hf_fti_encoding_symbol_length = -1;
static int hf_fti_max_source_block_length = -1;
static int hf_fti_max_number_encoding_symbols = -1;
static int hf_fti_num_blocks = -1;
static int hf_fti_num_subblocks = -1;
static int hf_fti_alignment = -1;
static int ett_main = -1;
static expert_field ei_fec_encoding_id = EI_INIT;
typedef struct fec_packet_data
{
guint8 instance_id;
} fec_packet_data_t;
/* String tables */
const value_string string_fec_encoding_id[] =
{
{ 0, "Compact No-Code" },
{ 1, "Raptor" },
{ 2, "Reed-Solomon Codes over GF(2^^m)" },
{ 3, "LDPC Staircase Codes" },
{ 4, "LDPC Triangle Codes" },
{ 5, "Reed-Solomon Codes over GF(2^^8)" },
{ 6, "RaptorQ Code" },
/* 7-127 Unassigned */
{ 128, "Small Block, Large Block and Expandable FEC Codes" },
{ 129, "Small Block Systematic FEC Codes" },
{ 130, "Compact FEC Codes" },
/* 131-255 Unassigned */
{ 0, NULL }
};
/* Dissection */
/* ---------- */
/* Decode an EXT_FTI extension and fill FEC array */
void fec_decode_ext_fti(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, int offset, guint8 encoding_id)
{
guint64 transfer_length;
fec_packet_data_t* fec_data;
guint8 instance_id = 0;
proto_item* ti;
if (encoding_id == 6){
/* Raptor Q uses 40-bit transfer length */
transfer_length = tvb_get_ntoh40(tvb, offset+2);
}
else {
/* Decode 48-bit length field */
transfer_length = tvb_get_ntoh48(tvb, offset+2);
}
if (encoding_id >= 128)
{
instance_id = (guint8) tvb_get_ntohs(tvb, offset+8);
/* Decode FEC Instance ID */
fec_data = wmem_new0(wmem_file_scope(), fec_packet_data_t);
fec_data->instance_id = instance_id;
p_add_proto_data(wmem_file_scope(), pinfo, proto_rmt_fec, 0, fec_data);
}
if (encoding_id == 6){
/* Raptor Q uses 40-bit transfer length */
proto_tree_add_uint64(tree, hf_fti_transfer_length, tvb, offset+2, 5, transfer_length);
}
else {
proto_tree_add_uint64(tree, hf_fti_transfer_length, tvb, offset+2, 6, transfer_length);
ti = proto_tree_add_item(tree, hf_instance_id, tvb, offset+8, 2, ENC_BIG_ENDIAN);
if ((encoding_id < 128) && (instance_id != 0)) {
expert_add_info(pinfo, ti, &ei_fec_encoding_id);
}
}
switch (encoding_id)
{
case 1:
proto_tree_add_item(tree, hf_fti_encoding_symbol_length, tvb, offset+10, 2, ENC_BIG_ENDIAN);
proto_tree_add_item(tree, hf_fti_num_blocks, tvb, offset+12, 2, ENC_BIG_ENDIAN);
proto_tree_add_item(tree, hf_fti_num_subblocks, tvb, offset+14, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(tree, hf_fti_alignment, tvb, offset+15, 1, ENC_BIG_ENDIAN);
break;
case 6:
proto_tree_add_item(tree, hf_fti_encoding_symbol_length, tvb, offset+8, 2, ENC_BIG_ENDIAN);
proto_tree_add_item(tree, hf_fti_num_blocks, tvb, offset+10, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(tree, hf_fti_num_subblocks, tvb, offset+11, 2, ENC_BIG_ENDIAN);
proto_tree_add_item(tree, hf_fti_alignment, tvb, offset+13, 1, ENC_BIG_ENDIAN);
break;
case 0:
case 2:
case 128:
case 130:
proto_tree_add_item(tree, hf_fti_encoding_symbol_length, tvb, offset+10, 2, ENC_BIG_ENDIAN);
proto_tree_add_item(tree, hf_fti_max_source_block_length, tvb, offset+12, 4, ENC_BIG_ENDIAN);
break;
case 129:
proto_tree_add_item(tree, hf_fti_encoding_symbol_length, tvb, offset+10, 2, ENC_BIG_ENDIAN);
proto_tree_add_item(tree, hf_fti_max_source_block_length, tvb, offset+12, 2, ENC_BIG_ENDIAN);
proto_tree_add_item(tree, hf_fti_max_number_encoding_symbols, tvb, offset+14, 2, ENC_BIG_ENDIAN);
break;
case 132:
proto_tree_add_item(tree, hf_fti_encoding_symbol_length, tvb, offset+10, 2, ENC_BIG_ENDIAN);
proto_tree_add_item(tree, hf_fti_max_source_block_length, tvb, offset+12, 4, ENC_BIG_ENDIAN);
proto_tree_add_item(tree, hf_fti_max_number_encoding_symbols, tvb, offset+16, 4, ENC_BIG_ENDIAN);
break;
}
}
/* Dissect a FEC header:
* fec - ptr to the logical FEC packet representation to fill
* hf - ptr to header fields array
* ett - ptr to ett array
* prefs - ptr to FEC prefs array
* tvb - buffer
* pinfo - packet info
* tree - tree where to add FEC header subtree
* offset - ptr to offset to use and update
*/
static int
dissect_fec(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
{
proto_item *ti;
proto_tree *fec_tree;
guint offset = 0;
fec_data_exchange_t* fec = (fec_data_exchange_t*)data;
guint8 encoding_id = 0;
fec_packet_data_t* packet_data = (fec_packet_data_t*)p_get_proto_data(wmem_file_scope(), pinfo, proto_rmt_fec, 0);
if (fec != NULL)
{
encoding_id = fec->encoding_id;
}
/* Create the FEC subtree */
ti = proto_tree_add_item(tree, proto_rmt_fec, tvb, offset, -1, ENC_NA);
fec_tree = proto_item_add_subtree(ti, ett_main);
proto_tree_add_uint(fec_tree, hf_encoding_id, tvb, offset, 0, encoding_id);
if (encoding_id >= 128 && (packet_data != NULL))
proto_tree_add_uint(fec_tree, hf_instance_id, tvb, offset, 0, packet_data->instance_id);
switch (encoding_id)
{
case 0:
case 1:
case 130:
proto_tree_add_item(fec_tree, hf_sbn, tvb, offset, 2, ENC_BIG_ENDIAN);
proto_tree_add_item(fec_tree, hf_esi, tvb, offset+2, 2, ENC_BIG_ENDIAN);
col_append_sep_fstr(pinfo->cinfo, COL_INFO, " ", "SBN: %u", tvb_get_ntohs(tvb, offset));
col_append_sep_fstr(pinfo->cinfo, COL_INFO, " ", "ESI: 0x%X", tvb_get_ntohs(tvb, offset+2));
offset += 4;
break;
case 2:
case 128:
case 132:
proto_tree_add_item(fec_tree, hf_sbn, tvb, offset, 4, ENC_BIG_ENDIAN);
proto_tree_add_item(fec_tree, hf_esi, tvb, offset+4, 4, ENC_BIG_ENDIAN);
col_append_sep_fstr(pinfo->cinfo, COL_INFO, " ", "SBN: %u", tvb_get_ntohl(tvb, offset));
col_append_sep_fstr(pinfo->cinfo, COL_INFO, " ", "ESI: 0x%X", tvb_get_ntohl(tvb, offset+4));
offset += 8;
break;
case 3:
case 4:
proto_tree_add_item(fec_tree, hf_sbn_with_mask, tvb, offset, 4, ENC_BIG_ENDIAN);
proto_tree_add_item(fec_tree, hf_esi_with_mask, tvb, offset, 4, ENC_BIG_ENDIAN);
col_append_sep_fstr(pinfo->cinfo, COL_INFO, " ", "SBN: %u", tvb_get_ntohl(tvb, offset) >> 20);
col_append_sep_fstr(pinfo->cinfo, COL_INFO, " ", "ESI: 0x%X", tvb_get_ntohl(tvb, offset) & 0xfffff);
offset += 4;
break;
case 6:
proto_tree_add_item(fec_tree, hf_sbn, tvb, offset, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(fec_tree, hf_esi, tvb, offset+1, 3, ENC_BIG_ENDIAN);
col_append_sep_fstr(pinfo->cinfo, COL_INFO, " ", "SBN: %u", tvb_get_guint8(tvb, offset));
col_append_sep_fstr(pinfo->cinfo, COL_INFO, " ", "ESI: 0x%X", tvb_get_ntoh24(tvb, offset+1));
offset += 4;
break;
case 129:
proto_tree_add_item(fec_tree, hf_sbn, tvb, offset, 4, ENC_BIG_ENDIAN);
proto_tree_add_item(fec_tree, hf_sbl, tvb, offset+4, 2, ENC_BIG_ENDIAN);
proto_tree_add_item(fec_tree, hf_esi, tvb, offset+6, 2, ENC_BIG_ENDIAN);
col_append_sep_fstr(pinfo->cinfo, COL_INFO, " ", "SBN: %u", tvb_get_ntohl(tvb, offset));
col_append_sep_fstr(pinfo->cinfo, COL_INFO, " ", "ESI: 0x%X", tvb_get_ntohs(tvb, offset+6));
offset += 8;
break;
}
return offset;
}
void proto_register_rmt_fec(void)
{
static hf_register_info hf[] = {
{ &hf_encoding_id,
{ "FEC Encoding ID", "rmt-fec.encoding_id", FT_UINT8, BASE_DEC, VALS(string_fec_encoding_id), 0x0, NULL, HFILL }},
{ &hf_instance_id,
{ "FEC Instance ID", "rmt-fec.instance_id", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }},
{ &hf_sbn,
{ "Source Block Number", "rmt-fec.sbn", FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL }},
{ &hf_sbn_with_mask,
{ "Source Block Number", "rmt-fec.sbn", FT_UINT32, BASE_DEC, NULL, 0xFFF00000, NULL, HFILL }},
{ &hf_sbl,
{ "Source Block Length", "rmt-fec.sbl", FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL }},
{ &hf_esi,
{ "Encoding Symbol ID", "rmt-fec.esi", FT_UINT32, BASE_HEX, NULL, 0x0, NULL, HFILL }},
{ &hf_esi_with_mask,
{ "Encoding Symbol ID", "rmt-fec.esi", FT_UINT32, BASE_HEX, NULL, 0x000FFFFF, NULL, HFILL }},
{ &hf_fti_transfer_length,
{ "Transfer Length", "rmt-fec.fti.transfer_length", FT_UINT64, BASE_DEC, NULL, 0x0, NULL, HFILL }},
{ &hf_fti_encoding_symbol_length,
{ "Encoding Symbol Length", "rmt-fec.fti.encoding_symbol_length", FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL }},
{ &hf_fti_max_source_block_length,
{ "Maximum Source Block Length", "rmt-fec.fti.max_source_block_length", FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL }},
{ &hf_fti_max_number_encoding_symbols,
{ "Maximum Number of Encoding Symbols", "rmt-fec.fti.max_number_encoding_symbols", FT_UINT32, BASE_DEC, NULL, 0x0, NULL, HFILL }},
{ &hf_fti_num_blocks,
{ "Number of Source Blocks", "rmt-fec.fti.num_blocks", FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL }},
{ &hf_fti_num_subblocks,
{ "Number of Sub-Blocks", "rmt-fec.fti.num_subblocks", FT_UINT16, BASE_DEC, NULL, 0x0, NULL, HFILL }},
{ &hf_fti_alignment,
{ "Symbol Alignment", "rmt-fec.fti.alignment", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }}
};
/* Setup protocol subtree array */
static gint *ett[] = {
&ett_main,
};
static ei_register_info ei[] = {
{ &ei_fec_encoding_id, { "rmt-fec.encoding_id.not0", PI_PROTOCOL, PI_WARN, "FEC Encoding ID < 128, should be zero", EXPFILL }},
};
expert_module_t* expert_rmt_fec;
/* Register the protocol name and description */
proto_rmt_fec = proto_register_protocol("Forward Error Correction (FEC)", "RMT-FEC", "rmt-fec");
new_register_dissector("rmt-fec", dissect_fec, proto_rmt_fec);
/* Required function calls to register the header fields and subtrees used */
proto_register_field_array(proto_rmt_fec, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
expert_rmt_fec = expert_register_protocol(proto_rmt_fec);
expert_register_field_array(expert_rmt_fec, ei, array_length(ei));
}
/*
* Editor modelines - http://www.wireshark.org/tools/modelines.html
*
* Local variables:
* c-basic-offset: 4
* tab-width: 8
* indent-tabs-mode: nil
* End:
*
* ex: set shiftwidth=4 tabstop=8 expandtab:
* :indentSize=4:tabSize=8:noTabs=true:
*/
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