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/* packet-git.c
* Routines for git packet dissection
* RFC 1939
* Copyright 2010, Jelmer Vernooij <jelmer@samba.org>
*
* $Id$
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998 Gerald Combs
*
* Copied from packet-pop.c
*
* 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.
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include <stdio.h>
#include <glib.h>
#include <epan/packet.h>
#include <epan/strutil.h>
#include <epan/prefs.h>
#include "packet-tcp.h"
static int proto_git = -1;
static gint ett_git = -1;
static gint hf_git_packet_len = -1;
static gint hf_git_packet_data = -1;
static gint hf_git_packet_terminator = -1;
#define TCP_PORT_GIT 9418
/* desegmentation of Git over TCP */
static gboolean git_desegment = TRUE;
static gboolean tvb_get_packet_length(tvbuff_t *tvb, int offset,
guint16 *length)
{
guint8 *lenstr;
lenstr = tvb_get_ephemeral_string(tvb, offset, 4);
return (sscanf(lenstr, "%hx", length) == 1);
}
static guint
get_git_pdu_len(packet_info *pinfo _U_, tvbuff_t *tvb, int offset)
{
guint16 plen;
if (!tvb_get_packet_length(tvb, offset, &plen))
return 0; /* No idea what this is */
if (plen == 0) {
/* Terminator packet */
return 4;
} else {
return plen;
}
}
static void
dissect_git_pdu(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
proto_tree *git_tree;
proto_item *ti;
int offset = 0;
guint16 plen;
col_set_str(pinfo->cinfo, COL_PROTOCOL, "GIT");
col_set_str(pinfo->cinfo, COL_INFO, "Git Smart Protocol");
ti = proto_tree_add_item(tree, proto_git, tvb, offset, -1, ENC_NA);
git_tree = proto_item_add_subtree(ti, ett_git);
if (!tvb_get_packet_length(tvb, 0, &plen))
return;
if (plen == 0) {
proto_tree_add_uint(git_tree, hf_git_packet_terminator, tvb, offset,
4, plen);
return;
}
if (git_tree)
{
proto_tree_add_uint(git_tree, hf_git_packet_len, tvb, offset,
4, plen);
proto_tree_add_item(git_tree, hf_git_packet_data, tvb, offset+4,
plen-4, ENC_NA);
}
}
static void
dissect_git(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
tcp_dissect_pdus(tvb, pinfo, tree, git_desegment, 4, get_git_pdu_len,
dissect_git_pdu);
}
void
proto_register_git(void)
{
static hf_register_info hf[] = {
{ &hf_git_packet_len,
{ "Packet length", "git.length", FT_UINT16, BASE_HEX, NULL, 0x0, NULL, HFILL },
},
{ &hf_git_packet_data,
{ "Packet data", "git.data", FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL },
},
{ &hf_git_packet_terminator,
{ "Terminator packet", "git.terminator", FT_UINT16, BASE_HEX, NULL, 0x0, NULL, HFILL },
},
};
static gint *ett[] = {
&ett_git,
};
module_t *git_module;
proto_git = proto_register_protocol("Git Smart Protocol", "GIT", "git");
register_dissector("git", dissect_git, proto_git);
proto_register_field_array(proto_git, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
git_module = prefs_register_protocol(proto_git, NULL);
prefs_register_bool_preference(git_module, "desegment",
"Reassemble GIT messages spanning multiple TCP segments",
"Whether the GIT dissector should reassemble messages spanning multiple TCP segments."
" To use this option, you must also enable \"Allow subdissectors to reassemble TCP streams\" in the TCP protocol settings.",
&git_desegment);
}
void
proto_reg_handoff_git(void)
{
dissector_handle_t git_handle;
git_handle = find_dissector("git");
dissector_add_uint("tcp.port", TCP_PORT_GIT, git_handle);
}
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