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/* packet-x29.c
* Routines for X.29 packet dissection
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998 Gerald Combs
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
#include "config.h"
#include <epan/packet.h>
#include <epan/nlpid.h>
void proto_register_x29(void);
void proto_reg_handoff_x29(void);
static dissector_handle_t x29_handle;
static int proto_x29;
static int hf_msg_code;
static int hf_error_type;
static int hf_inv_msg_code;
/* Generated from convert_proto_tree_add_text.pl */
static int hf_x29_pad_message_data;
static int hf_x29_type_reference_value;
static int hf_x29_type_reference;
static int hf_x29_data;
static int hf_x29_type_of_aspect;
static int hf_x29_reselection_message_data;
static int hf_x29_break_value;
static int hf_x29_parameter;
static int hf_x29_value;
static int ett_x29;
/*
* PAD messages.
*/
#define SET_MSG 0x02
#define READ_MSG 0x04
#define SET_AND_READ_MSG 0x06
#define PARAMETER_IND_MSG 0x00
#define INV_TO_CLEAR_MSG 0x01
#define BREAK_IND_MSG 0x03
#define RESELECTION_MSG 0x07
#define ERROR_MSG 0x05
#define RESEL_WITH_TOA_NPI_MSG 0x08
static const value_string message_code_vals[] = {
{ SET_MSG, "Set" },
{ READ_MSG, "Read" },
{ SET_AND_READ_MSG, "Set and read" },
{ PARAMETER_IND_MSG, "Parameter indication" },
{ INV_TO_CLEAR_MSG, "Invitation to clear" },
{ BREAK_IND_MSG, "Indication of break" },
{ RESELECTION_MSG, "Reselection" },
{ ERROR_MSG, "Error" },
{ RESEL_WITH_TOA_NPI_MSG, "Reselection with TOA/NPI" },
{ 0, NULL }
};
static const value_string error_type_vals[] = {
{ 0x00, "Received PAD message contained less than eight bits" },
{ 0x02, "Unrecognized message code in received PAD message" },
{ 0x04, "Parameter field format was incorrect or incompatible with message code" },
{ 0x06, "Received PAD message did not contain an integral number of octets" },
{ 0x08, "Received Parameter Indication PAD message was unsolicited" },
{ 0x0A, "Received PAD message was too long" },
{ 0x0C, "Unauthorized reselection PAD message" },
{ 0, NULL },
};
static const value_string reference_type_vals[] = {
{ 0x01, "Change in PAD Aspect" },
{ 0x08, "Break" },
{ 0, NULL },
};
static int
dissect_x29(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data)
{
int offset = 0;
proto_tree *x29_tree;
proto_item *ti;
bool *q_bit_set;
uint8_t msg_code;
uint8_t error_type;
uint8_t type_ref;
int next_offset;
int linelen;
/* Reject the packet if data is NULL */
if (data == NULL)
return 0;
q_bit_set = (bool *)data;
col_set_str(pinfo->cinfo, COL_PROTOCOL, "X.29");
col_clear(pinfo->cinfo, COL_INFO);
ti = proto_tree_add_item(tree, proto_x29, tvb, offset, -1, ENC_NA);
x29_tree = proto_item_add_subtree(ti, ett_x29);
if (*q_bit_set) {
/*
* Q bit set - this is a PAD message.
*/
msg_code = tvb_get_uint8(tvb, offset);
col_add_fstr(pinfo->cinfo, COL_INFO, "%s PAD message",
val_to_str(msg_code, message_code_vals,
"Unknown (0x%02x)"));
proto_tree_add_uint(x29_tree, hf_msg_code, tvb,
offset, 1, msg_code);
offset++;
switch (msg_code) {
case SET_MSG:
case READ_MSG:
case SET_AND_READ_MSG:
case PARAMETER_IND_MSG:
/*
* XXX - dissect the references as per X.3.
*/
while (tvb_reported_length_remaining(tvb, offset) > 0) {
proto_tree_add_item(x29_tree, hf_x29_parameter, tvb, offset, 1, ENC_BIG_ENDIAN);
offset++;
proto_tree_add_item(x29_tree, hf_x29_value, tvb, offset, 1, ENC_BIG_ENDIAN);
offset++;
}
break;
case INV_TO_CLEAR_MSG:
/*
* No data for this message.
*/
break;
case ERROR_MSG:
error_type = tvb_get_uint8(tvb, offset);
proto_tree_add_uint(x29_tree, hf_error_type, tvb,
offset, 1, error_type);
offset++;
if (error_type != 0) {
proto_tree_add_item(x29_tree, hf_inv_msg_code,
tvb, offset, 1, ENC_BIG_ENDIAN);
}
break;
case BREAK_IND_MSG:
if (tvb_reported_length_remaining(tvb, offset) > 0) {
type_ref = tvb_get_uint8(tvb, offset);
proto_tree_add_item(x29_tree, hf_x29_type_reference, tvb, offset, 1, ENC_BIG_ENDIAN);
offset++;
switch (type_ref) {
case 0x01: /* change in PAD Aspect */
/*
* XXX - dissect as per X.28.
*/
proto_tree_add_item(x29_tree, hf_x29_type_of_aspect, tvb, offset, 1, ENC_BIG_ENDIAN);
offset++;
break;
case 0x08: /* break */
proto_tree_add_item(x29_tree, hf_x29_break_value, tvb, offset, 1, ENC_BIG_ENDIAN);
offset++;
break;
default:
proto_tree_add_item(x29_tree, hf_x29_type_reference_value, tvb, offset, 1, ENC_BIG_ENDIAN);
offset++;
break;
}
}
break;
case RESELECTION_MSG:
/*
* XXX - dissect me.
*/
proto_tree_add_item(x29_tree, hf_x29_reselection_message_data, tvb, offset, -1, ENC_NA);
break;
case RESEL_WITH_TOA_NPI_MSG:
/*
* XXX - dissect me.
*/
proto_tree_add_item(x29_tree, hf_x29_reselection_message_data, tvb, offset, -1, ENC_NA);
break;
default:
proto_tree_add_item(x29_tree, hf_x29_pad_message_data, tvb, offset, -1, ENC_NA);
break;
}
} else {
/*
* Q bit not set - this is data.
*/
col_set_str(pinfo->cinfo, COL_INFO, "Data ...");
if (tree) {
while (tvb_offset_exists(tvb, offset)) {
/*
* Find the end of the line.
*/
tvb_find_line_end(tvb, offset, -1,
&next_offset, false);
/*
* Now compute the length of the line
* *including* the end-of-line indication,
* if any; we display it all.
*/
linelen = next_offset - offset;
proto_tree_add_item(x29_tree, hf_x29_data, tvb, offset, linelen, ENC_NA|ENC_ASCII);
offset = next_offset;
}
}
}
return tvb_captured_length(tvb);
}
void
proto_register_x29(void)
{
static hf_register_info hf[] = {
{ &hf_msg_code,
{ "Message code", "x29.msg_code", FT_UINT8, BASE_HEX,
VALS(message_code_vals), 0x0, "X.29 PAD message code",
HFILL }},
{ &hf_error_type,
{ "Error type", "x29.error_type", FT_UINT8, BASE_HEX,
VALS(error_type_vals), 0x0, "X.29 error PAD message error type",
HFILL }},
{ &hf_inv_msg_code,
{ "Invalid message code", "x29.inv_msg_code", FT_UINT8, BASE_HEX,
VALS(message_code_vals), 0x0, "X.29 Error PAD message invalid message code",
HFILL }},
/* Generated from convert_proto_tree_add_text.pl */
{ &hf_x29_type_reference, { "Type reference", "x29.type_reference", FT_UINT8, BASE_DEC, VALS(reference_type_vals), 0x0, NULL, HFILL }},
{ &hf_x29_type_of_aspect, { "Type of aspect", "x29.type_of_aspect", FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL }},
{ &hf_x29_break_value, { "Break value", "x29.break_value", FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL }},
{ &hf_x29_type_reference_value, { "Type value", "x29.type_reference.value", FT_UINT8, BASE_HEX, NULL, 0x0, NULL, HFILL }},
{ &hf_x29_reselection_message_data, { "Reselection message data", "x29.reselection_message_data", FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL }},
{ &hf_x29_pad_message_data, { "PAD message data", "x29.pad_message_data", FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL }},
{ &hf_x29_data, { "Data", "x29.data", FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL }},
{ &hf_x29_parameter, { "Parameter", "x29.parameter", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }},
{ &hf_x29_value, { "Value", "x29.value", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }},
};
static int *ett[] = {
&ett_x29,
};
proto_x29 = proto_register_protocol("X.29", "X.29", "x29");
x29_handle = register_dissector("x29", dissect_x29, proto_x29);
proto_register_field_array(proto_x29, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
}
void
proto_reg_handoff_x29(void)
{
dissector_add_uint("x.25.spi", NLPID_SPI_X_29, x29_handle);
}
/*
* Editor modelines - https://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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