wireshark/epan/dissectors/packet-bzr.c
Michael Mann 268841f3e0 Combine Decode As and port preferences for tcp.port dissector table.
This patch introduces new APIs to allow dissectors to have a preference for
a (TCP) port, but the underlying data is actually part of Decode As functionality.
For now the APIs are intentionally separate from the regular APIs that register a
dissector within a dissector table.  It may be possible to eventually combine the
two so that all dissectors that register with a dissector table have an opportunity
to "automatically" have a preference to adjust the "table value" through the
preferences dialog.

The tcp.port dissector table was used as the guinea pig.  This will eventually be
expanded to other dissector tables as well (most notably UDP ports).  Some
dissectors that "shared" a TCP/UDP port preference were also converted. It also
removed the need for some preference callback functions (mostly when the callback
function was the proto_reg_handoff function) so there is cleanup around that.

Dissectors that has a port preference whose default was 0 were switched to using
the dissector_add_for_decode_as_with_preference API rather than dissector_add_uint_with_preference

Also added comments for TCP ports used that aren't IANA registered.

Change-Id: I99604f95d426ad345f4b494598d94178b886eb67
Reviewed-on: https://code.wireshark.org/review/17724
Reviewed-by: Michael Mann <mmann78@netscape.net>
2016-10-08 02:44:53 +00:00

342 lines
10 KiB
C

/* packet-bzr.c
* Routines for Bazaar packet dissection
* Copyright 2011,2013 Jelmer Vernooij <jelmer@samba.org>
*
* http://doc.bazaar.canonical.com/developers/network-protocol.html
*
* 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.
*/
#include "config.h"
#include <epan/packet.h>
#include <epan/prefs.h>
void proto_register_bzr(void);
void proto_reg_handoff_bzr(void);
static int proto_bzr = -1;
static gint ett_bzr = -1;
static gint ett_prefixed_bencode = -1;
static gint ett_prefixed_bytes = -1;
static gint hf_bzr_prefixed_bencode = -1;
static gint hf_bzr_prefixed_bencode_len = -1;
static gint hf_bzr_bytes = -1;
static gint hf_bzr_bytes_data = -1;
static gint hf_bzr_bytes_length = -1;
static gint hf_bzr_result = -1;
static gint hf_bzr_packet_protocol_version = -1;
static gint hf_bzr_packet_kind = -1;
static dissector_handle_t bencode_handle;
#define REQUEST_VERSION_TWO "bzr request 2\n"
#define RESPONSE_VERSION_TWO "bzr response 2\n"
#define MESSAGE_VERSION_THREE "bzr message 3 (bzr 1.6)\n"
#define TCP_PORT_BZR 4155
static const value_string message_part_kind[] = {
{'s', "Structure"},
{'b', "Bytes"},
{'o', "Single byte"},
{'e', "End"},
{0, NULL}
};
static const value_string message_results[] = {
{'S', "Success"},
{'E', "Error"},
{0, NULL}
};
/* desegmentation of Bazaar over TCP */
static gboolean bzr_desegment = TRUE;
static guint get_bzr_prefixed_len(tvbuff_t *tvb, int offset)
{
guint header_len;
header_len = tvb_get_ntohl(tvb, offset);
return 4 + header_len;
}
static guint
get_bzr_pdu_len(packet_info *pinfo _U_, tvbuff_t *tvb, int offset)
{
int next_offset;
gint len = 0;
gint protocol_version_len;
guint8 cmd = 0;
/* Protocol version */
protocol_version_len = tvb_find_line_end(tvb, offset, -1, &next_offset,
TRUE);
if (protocol_version_len == -1) /* End of the packet not seen yet */
return -1;
len += protocol_version_len + 1;
/* Headers */
len += get_bzr_prefixed_len(tvb, next_offset);
while (tvb_reported_length_remaining(tvb, offset + len) > 0) {
cmd = tvb_get_guint8(tvb, offset + len);
len += 1;
switch (cmd) {
case 's':
case 'b':
len += get_bzr_prefixed_len(tvb, offset + len);
break;
case 'o':
len += 1;
break;
case 'e':
return len;
}
}
return -1;
}
static gint
dissect_prefixed_bencode(tvbuff_t *tvb, gint offset, packet_info *pinfo,
proto_tree *tree)
{
guint32 plen;
proto_tree *prefixed_bencode_tree;
proto_item *ti;
tvbuff_t *subtvb;
plen = tvb_get_ntohl(tvb, offset);
ti = proto_tree_add_item(tree, hf_bzr_prefixed_bencode, tvb, offset, 4 +
plen, ENC_NA);
prefixed_bencode_tree = proto_item_add_subtree(ti, ett_prefixed_bencode);
proto_tree_add_item(prefixed_bencode_tree, hf_bzr_prefixed_bencode_len,
tvb, offset, 4, ENC_BIG_ENDIAN);
subtvb = tvb_new_subset_length(tvb, offset+4, plen);
call_dissector(bencode_handle, subtvb, pinfo, prefixed_bencode_tree);
return 4 + plen;
}
static gint
dissect_prefixed_bytes(tvbuff_t *tvb, gint offset, packet_info *pinfo _U_,
proto_tree *tree)
{
guint32 plen;
proto_tree *prefixed_bytes_tree;
proto_item *ti;
plen = tvb_get_ntohl(tvb, offset);
ti = proto_tree_add_item(tree, hf_bzr_bytes, tvb, offset, 4 +
plen, ENC_NA);
prefixed_bytes_tree = proto_item_add_subtree(ti, ett_prefixed_bytes);
if (prefixed_bytes_tree)
{
proto_tree_add_item(prefixed_bytes_tree, hf_bzr_bytes_length,
tvb, offset, 4, ENC_BIG_ENDIAN);
proto_tree_add_item(prefixed_bytes_tree, hf_bzr_bytes_data,
tvb, offset+4, plen, ENC_NA);
}
return 4 + plen;
}
static gint
dissect_body(tvbuff_t *tvb, gint offset, packet_info *pinfo, proto_tree *tree)
{
guint8 cmd = 0;
while (tvb_reported_length_remaining(tvb, offset) > 0) {
cmd = tvb_get_guint8(tvb, offset);
proto_tree_add_item(tree, hf_bzr_packet_kind, tvb, offset, 1, ENC_ASCII|ENC_NA);
offset += 1;
switch (cmd) {
case 's':
offset += dissect_prefixed_bencode(tvb, offset, pinfo, tree);
break;
case 'b':
offset += dissect_prefixed_bytes(tvb, offset, pinfo, tree);
break;
case 'o':
proto_tree_add_item(tree, hf_bzr_result, tvb, offset, 1,
ENC_ASCII|ENC_NA);
offset += 1;
break;
case 'e':
break;
}
}
return offset;
}
static void
dissect_bzr_pdu(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
{
proto_tree *bzr_tree;
proto_item *ti;
int offset = 0;
gint protocol_version_len;
ti = proto_tree_add_item(tree, proto_bzr, tvb, offset, -1, ENC_NA);
bzr_tree = proto_item_add_subtree(ti, ett_bzr);
protocol_version_len = tvb_find_line_end(tvb, offset, -1, &offset, TRUE);
if (protocol_version_len == -1) /* Invalid packet */
return;
if (bzr_tree)
{
proto_tree_add_item(bzr_tree, hf_bzr_packet_protocol_version, tvb, 0,
protocol_version_len+1, ENC_ASCII|ENC_NA);
}
offset += dissect_prefixed_bencode(tvb, offset, pinfo, bzr_tree);
/*offset +=*/ dissect_body(tvb, offset, pinfo, bzr_tree);
}
static int
dissect_bzr(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
{
gint offset = 0, pdu_len;
tvbuff_t *next_tvb;
col_set_str(pinfo->cinfo, COL_PROTOCOL, "BZR");
col_set_str(pinfo->cinfo, COL_INFO, "Bazaar Smart Protocol");
while (tvb_reported_length_remaining(tvb, offset) > 0) {
pdu_len = get_bzr_pdu_len(pinfo, tvb, offset);
if (pdu_len == -1) {
if (pinfo->can_desegment && bzr_desegment) {
pinfo->desegment_offset = offset;
pinfo->desegment_len = DESEGMENT_ONE_MORE_SEGMENT;
return tvb_captured_length(tvb);
} else {
pdu_len = tvb_reported_length_remaining(tvb, offset);
}
}
next_tvb = tvb_new_subset_length(tvb, offset, pdu_len);
dissect_bzr_pdu(next_tvb, pinfo, tree);
offset += pdu_len;
}
return tvb_captured_length(tvb);
}
void
proto_register_bzr(void)
{
static hf_register_info hf[] = {
{ &hf_bzr_packet_kind,
{ "Packet kind", "bzr.kind", FT_CHAR, BASE_HEX,
VALS(message_part_kind), 0x0, NULL, HFILL },
},
{ &hf_bzr_packet_protocol_version,
{ "Protocol version", "bzr.protocol_version", FT_STRING, BASE_NONE,
NULL, 0x0, NULL, HFILL },
},
{ &hf_bzr_prefixed_bencode,
{ "Bencode packet", "bzr.bencode", FT_BYTES, BASE_NONE, NULL, 0x0,
"Serialized structure of integers, dictionaries, strings and "
"lists.", HFILL },
},
{ &hf_bzr_prefixed_bencode_len,
{ "Bencode packet length", "bzr.bencode.length", FT_UINT32,
BASE_HEX, NULL, 0x0, NULL, HFILL },
},
{ &hf_bzr_bytes,
{ "Prefixed bytes", "bzr.bytes", FT_BYTES, BASE_NONE, NULL, 0x0,
"Bytes field with prefixed 32-bit length", HFILL },
},
{ &hf_bzr_bytes_data,
{ "Prefixed bytes data", "bzr.bytes.data", FT_BYTES, BASE_NONE,
NULL, 0x0, NULL, HFILL },
},
{ &hf_bzr_bytes_length,
{ "Prefixed bytes length", "bzr.bytes.length", FT_UINT32, BASE_HEX,
NULL, 0x0, NULL, HFILL },
},
{ &hf_bzr_result,
{ "Result", "bzr.result", FT_CHAR, BASE_HEX,
VALS(message_results), 0x0,
"Command result (success or failure with error message)", HFILL
},
},
};
static gint *ett[] = {
&ett_bzr,
&ett_prefixed_bencode,
&ett_prefixed_bytes,
};
module_t *bzr_module;
proto_bzr = proto_register_protocol("Bazaar Smart Protocol", "Bazaar", "bzr");
register_dissector("bzr", dissect_bzr, proto_bzr);
proto_register_field_array(proto_bzr, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
bzr_module = prefs_register_protocol(proto_bzr, NULL);
prefs_register_bool_preference(bzr_module, "desegment",
"Reassemble Bazaar messages spanning multiple TCP segments",
"Whether the Bazaar 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.",
&bzr_desegment);
}
void
proto_reg_handoff_bzr(void)
{
dissector_handle_t bzr_handle;
bencode_handle = find_dissector_add_dependency("bencode", proto_bzr);
bzr_handle = find_dissector("bzr");
dissector_add_uint_with_preference("tcp.port", TCP_PORT_BZR, bzr_handle);
}
/*
* Editor modelines - http://www.wireshark.org/tools/modelines.html
*
* Local variables:
* c-basic-offset: 4
* tab-width: 8
* indent-tabs-mode: nil
* End:
*
* vi: set shiftwidth=4 tabstop=8 expandtab:
* :indentSize=4:tabSize=8:noTabs=true:
*/