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wireshark/epan/dissectors/packet-rudp.c
Michael Mann ad6fc87d64 Add proto_tree_add_checksum. 
This is an attempt to standardize display/handling of checksum fields for all dissectors.
The main target is for dissectors that do validation, but dissectors that just report the
checksum were also included just to make them easier to find in the future.

Bug: 10620
Bug: 12058
Ping-Bug: 8859
Change-Id: Ia8abd86e42eaf8ed50de6b173409e914b17993bf
Reviewed-on: https://code.wireshark.org/review/16380
Petri-Dish: Michael Mann <mmann78@netscape.net>
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Jeff Morriss <jeff.morriss.ws@gmail.com>
Reviewed-by: Michael Mann <mmann78@netscape.net>
2016-07-21 12:35:22 +00:00

274 lines
7.4 KiB
C
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/* packet-rudp.c
* Routines for Reliable UDP Protocol.
* Copyright 2004, Duncan Sargeant <dunc-ethereal@rcpt.to>
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998 Gerald Combs
*
* Copied from packet-data.c, README.developer, and various other files.
*
* 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.
* Reliable UDP is a lightweight protocol for providing TCP-like flow
* control over UDP. Cisco published an PFC a long time ago, and
* their actual implementation is slightly different, having no
* checksum field.
*
* I've cheated here - RUDP could be used for anything, but I've only
* seen it used to switched telephony calls, so we just call the Cisco SM
* dissector from here.
*
* Here are some links:
*
* http://www.watersprings.org/pub/id/draft-ietf-sigtran-reliable-udp-00.txt
* http://www.javvin.com/protocolRUDP.html
* http://www.cisco.com/univercd/cc/td/doc/product/access/sc/rel7/omts/omts_apb.htm#30052
*/
#include "config.h"
#include <epan/packet.h>
#include <epan/prefs.h>
void proto_register_rudp(void);
/* Disable rudp by default. The previously hardcoded value of
* 7000 (used by Cisco) collides with afs and as the draft states:
* "RUDP doesn't place any restrictions on which UDP port numbers are used.
* Valid port numbers are ports not defined in RFC 1700."
*/
/* FIXME: The proper solution would be to convert this dissector into
* heuristic dissector, but it isn't complete anyway.
*/
static guint udp_port = 0;
void proto_reg_handoff_rudp(void);
static int proto_rudp = -1;
static int hf_rudp_flags = -1;
static int hf_rudp_flags_syn = -1;
static int hf_rudp_flags_ack = -1;
static int hf_rudp_flags_eak = -1;
static int hf_rudp_flags_rst = -1;
static int hf_rudp_flags_nul = -1;
static int hf_rudp_flags_chk = -1;
static int hf_rudp_flags_tcs = -1;
static int hf_rudp_flags_0 = -1;
static int hf_rudp_hlen = -1;
static int hf_rudp_seq = -1;
static int hf_rudp_ack = -1;
static int hf_rudp_cksum = -1;
static gint ett_rudp = -1;
static gint ett_rudp_flags = -1;
static dissector_handle_t sm_handle = NULL;
static int
dissect_rudp(tvbuff_t *tvb, packet_info *pinfo _U_ , proto_tree *tree, void* data _U_)
{
tvbuff_t * next_tvb;
proto_tree *rudp_tree;
proto_item *ti;
guint8 hlen;
static const int * flags[] = {
&hf_rudp_flags_syn,
&hf_rudp_flags_ack,
&hf_rudp_flags_eak,
&hf_rudp_flags_rst,
&hf_rudp_flags_nul,
&hf_rudp_flags_chk,
&hf_rudp_flags_tcs,
&hf_rudp_flags_0,
NULL
};
hlen = tvb_get_guint8(tvb, 1);
col_set_str(pinfo->cinfo, COL_PROTOCOL, "RUDP");
col_clear(pinfo->cinfo, COL_INFO);
ti = proto_tree_add_item(tree, proto_rudp, tvb, 0, hlen, ENC_NA);
rudp_tree = proto_item_add_subtree(ti, ett_rudp);
proto_tree_add_bitmask(rudp_tree, tvb, 0, hf_rudp_flags, ett_rudp_flags, flags, ENC_BIG_ENDIAN);
proto_tree_add_item(rudp_tree, hf_rudp_hlen, tvb, 1, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(rudp_tree, hf_rudp_seq, tvb, 2, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(rudp_tree, hf_rudp_ack, tvb, 3, 1, ENC_BIG_ENDIAN);
/* If the header is more than 4 bytes the next 2 bytes are the checksum */
if (hlen > 4) {
proto_tree_add_checksum(rudp_tree, tvb, 4, hf_rudp_cksum, -1, NULL, pinfo, 0, ENC_BIG_ENDIAN, PROTO_CHECKSUM_NO_FLAGS);
}
/* If we have even more bytes their meaning is unknown - we have seen this
* in live captures */
if (hlen > 6) {
next_tvb = tvb_new_subset_length(tvb, 6, hlen-6);
call_data_dissector(next_tvb, pinfo, rudp_tree);
}
next_tvb = tvb_new_subset_remaining(tvb, hlen);
if (tvb_captured_length(next_tvb) && sm_handle)
call_dissector(sm_handle, next_tvb, pinfo, tree);
return tvb_captured_length(tvb);
}
void
proto_register_rudp(void)
{
static hf_register_info hf[] = {
{ &hf_rudp_flags,
{ "RUDP Header flags", "rudp.flags",
FT_UINT8, BASE_DEC, NULL, 0x0,
NULL, HFILL }
},
{ &hf_rudp_flags_syn,
{ "Syn", "rudp.flags.syn",
FT_BOOLEAN, 8, NULL, 0x80,
NULL, HFILL }
},
{ &hf_rudp_flags_ack,
{ "Ack", "rudp.flags.ack",
FT_BOOLEAN, 8, NULL, 0x40,
NULL, HFILL }
},
{ &hf_rudp_flags_eak,
{ "Eak", "rudp.flags.eak",
FT_BOOLEAN, 8, NULL, 0x20,
"Extended Ack", HFILL }
},
{ &hf_rudp_flags_rst,
{ "RST", "rudp.flags.rst",
FT_BOOLEAN, 8, NULL, 0x10,
"Reset flag", HFILL }
},
{ &hf_rudp_flags_nul,
{ "NULL", "rudp.flags.nul",
FT_BOOLEAN, 8, NULL, 0x08,
"Null flag", HFILL }
},
{ &hf_rudp_flags_chk,
{ "CHK", "rudp.flags.chk",
FT_BOOLEAN, 8, NULL, 0x04,
"Checksum is on header or body", HFILL }
},
{ &hf_rudp_flags_tcs,
{ "TCS", "rudp.flags.tcs",
FT_BOOLEAN, 8, NULL, 0x02,
"Transfer Connection System", HFILL }
},
{ &hf_rudp_flags_0,
{ "0", "rudp.flags.0",
FT_BOOLEAN, 8, NULL, 0x01,
NULL, HFILL }
},
{ &hf_rudp_hlen,
{ "Header Length", "rudp.hlen",
FT_UINT8, BASE_DEC, NULL, 0x0,
NULL, HFILL }
},
{ &hf_rudp_seq,
{ "Seq", "rudp.seq",
FT_UINT8, BASE_DEC, NULL, 0x0,
"Sequence Number", HFILL }
},
{ &hf_rudp_ack,
{ "Ack", "rudp.ack",
FT_UINT8, BASE_DEC, NULL, 0x0,
"Acknowledgement Number", HFILL }
},
{ &hf_rudp_cksum,
{ "Checksum", "rudp.cksum",
FT_UINT16, BASE_HEX, NULL, 0x0,
NULL, HFILL }
},
};
/* Setup protocol subtree array */
static gint *ett[] = {
&ett_rudp,
&ett_rudp_flags,
};
proto_rudp = proto_register_protocol (
"Reliable UDP", /* name */
"RUDP", /* short name */
"rudp" /* abbrev */
);
proto_register_field_array(proto_rudp, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
{
module_t *rudp_module;
rudp_module = prefs_register_protocol(proto_rudp, proto_reg_handoff_rudp);
prefs_register_uint_preference(rudp_module,
"udp.port",
"UDP port for RUDP",
"Set the UDP port for Reliable UDP traffic",
10,
&udp_port);
}
}
void
proto_reg_handoff_rudp(void) {
static gboolean initialized = FALSE;
static dissector_handle_t rudp_handle;
static guint saved_udp_port;
if (!initialized) {
rudp_handle = create_dissector_handle(dissect_rudp, proto_rudp);
dissector_add_for_decode_as("udp.port", rudp_handle);
sm_handle = find_dissector_add_dependency("sm", proto_rudp);
initialized = TRUE;
} else {
if (saved_udp_port != 0) {
dissector_delete_uint("udp.port", saved_udp_port, rudp_handle);
}
}
if (udp_port != 0) {
dissector_add_uint("udp.port", udp_port, rudp_handle);
}
saved_udp_port = udp_port;
}
/*
* Editor modelines - http://www.wireshark.org/tools/modelines.html
*
* Local variables:
* c-basic-offset: 8
* tab-width: 8
* indent-tabs-mode: t
* End:
*
* vi: set shiftwidth=8 tabstop=8 noexpandtab:
* :indentSize=8:tabSize=8:noTabs=false:
*/
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