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/* packet-rmt-common.c
* Reliable Multicast Transport (RMT)
* Common RMT functions
* Copyright 2005, Stefano Pettini <spettini@users.sourceforge.net>
*
* $Id$
*
* 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 <string.h>
#include <glib.h>
#include <epan/packet.h>
#include <epan/strutil.h>
#include "packet-rmt-common.h"
/* Common RMT exported functions */
/* ============================= */
/* Scan the tvb and put extensions found in an array */
void rmt_ext_parse(GArray *a, tvbuff_t *tvb, guint *offset, guint offset_max)
{
struct _ext e;
while (*offset < offset_max)
{
/* Clear the temporary extension */
memset(&e, 0, sizeof(struct _ext));
/* Dissect the extension */
e.offset = *offset;
e.het = tvb_get_guint8(tvb, *offset);
if (e.het <= 127) {
/* If HET <= 127, we have a variable-size extension */
e.hel = tvb_get_guint8(tvb, *offset+1);
e.hec_offset = *offset + 2;
e.hec_size = e.hel * 4 - 2;
e.length = e.hel * 4;
} else {
/* If HET > 127, we have a short 32-bit extension */
e.hel = 1; /* even if HEL field is not defined for HET > 127 */
e.hec_offset = *offset + 1;
e.hec_size = 3;
e.length = 4;
}
/* Prevents infinite loops */
if (e.length == 0)
break;
g_array_append_val(a, e);
*offset += e.length;
}
}
/* Add default items to a subtree */
void rmt_ext_decode_default_header(struct _ext *e, tvbuff_t *tvb, proto_tree *tree)
{
if (tree)
{
proto_tree_add_text(tree, tvb, e->offset, 1, "Header Extension Type (HET): %u", e->het);
if (e->het <= 127)
proto_tree_add_text(tree, tvb, e->offset+1, 1, "Header Extension Length (HEL): %u", e->hel);
}
}
/* Add a default subtree to a tree item */
void rmt_ext_decode_default_subtree(struct _ext *e, tvbuff_t *tvb, proto_item *ti, gint ett)
{
proto_tree *ext_tree;
ext_tree = proto_item_add_subtree(ti, ett);
rmt_ext_decode_default_header(e, tvb, ext_tree);
if (ext_tree)
proto_tree_add_text(ext_tree, tvb, e->hec_offset, e->hec_size,
"Header Extension Content (HEC): %s", tvb_bytes_to_str(tvb, e->hec_offset, e->hec_size));
}
/* Add a default subtree for unknown extensions */
void rmt_ext_decode_default(struct _ext *e, tvbuff_t *tvb, proto_tree *tree, gint ett)
{
proto_item *ti;
if (tree)
{
ti = proto_tree_add_text(tree, tvb, e->offset, e->length,
"Unknown extension (%u)", e->het);
rmt_ext_decode_default_subtree(e, tvb, ti, ett);
}
}
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