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|
/* packet-v120.c
* Routines for v120 frame disassembly
* Bert Driehuis <driehuis@playbeing.org>
*
* Wireshark - Network traffic analyzer
* By Gerald Combs <gerald@wireshark.org>
* Copyright 1998
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
#include "config.h"
#include <epan/packet.h>
#include <epan/xdlc.h>
void proto_register_v120(void);
static int proto_v120;
static int hf_v120_address;
static int hf_v120_rc;
static int hf_v120_lli;
static int hf_v120_ea0;
static int hf_v120_ea1;
static int hf_v120_control;
static int hf_v120_n_r;
static int hf_v120_n_s;
static int hf_v120_p;
static int hf_v120_p_ext;
static int hf_v120_f;
static int hf_v120_f_ext;
static int hf_v120_s_ftype;
static int hf_v120_u_modifier_cmd;
static int hf_v120_u_modifier_resp;
static int hf_v120_ftype_i;
static int hf_v120_ftype_s_u;
static int hf_v120_ftype_s_u_ext;
static int hf_v120_header8;
static int hf_v120_header_ext8;
static int hf_v120_header_break8;
static int hf_v120_header_error_control8;
static int hf_v120_header_segb8;
static int hf_v120_header_segf8;
static int hf_v120_header16;
static int hf_v120_header_ext16;
static int hf_v120_header_break16;
static int hf_v120_header_error_control16;
static int hf_v120_header_segb16;
static int hf_v120_header_segf16;
static int hf_v120_header_e;
static int hf_v120_header_dr;
static int hf_v120_header_sr;
static int hf_v120_header_rr;
static int ett_v120;
static int ett_v120_address;
static int ett_v120_control;
static int ett_v120_header;
static int dissect_v120_header(tvbuff_t *tvb, int offset, proto_tree *tree);
/* Used only for U frames */
static const xdlc_cf_items v120_cf_items = {
NULL,
NULL,
&hf_v120_p,
&hf_v120_f,
NULL,
&hf_v120_u_modifier_cmd,
&hf_v120_u_modifier_resp,
NULL,
&hf_v120_ftype_s_u
};
/* Used only for I and S frames */
static const xdlc_cf_items v120_cf_items_ext = {
&hf_v120_n_r,
&hf_v120_n_s,
&hf_v120_p_ext,
&hf_v120_f_ext,
&hf_v120_s_ftype,
NULL,
NULL,
&hf_v120_ftype_i,
&hf_v120_ftype_s_u_ext
};
static int
dissect_v120(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
{
proto_tree *v120_tree, *address_tree;
proto_item *ti, *tc;
int is_response;
int v120len;
uint8_t byte0, byte1;
uint16_t control;
tvbuff_t *next_tvb;
col_set_str(pinfo->cinfo, COL_PROTOCOL, "V.120");
col_clear(pinfo->cinfo, COL_INFO);
byte0 = tvb_get_uint8(tvb, 0);
col_add_fstr(pinfo->cinfo, COL_RES_DL_SRC, "0x%02X", byte0);
byte1 = tvb_get_uint8(tvb, 1);
if ( ((byte0 & 0x01) != 0x00) && ((byte1 & 0x01) != 0x01) )
{
col_set_str(pinfo->cinfo, COL_INFO, "Invalid V.120 frame");
if (tree)
proto_tree_add_protocol_format(tree, proto_v120, tvb, 0, -1,
"Invalid V.120 frame");
return 2;
}
if (pinfo->p2p_dir == P2P_DIR_SENT) {
is_response = (byte0 & 0x02) ? false: true;
col_set_str(pinfo->cinfo, COL_RES_DL_DST, "DCE");
col_set_str(pinfo->cinfo, COL_RES_DL_SRC, "DTE");
} else {
/* XXX - what if the direction is unknown? */
is_response = (byte0 & 0x02) ? true : false;
col_set_str(pinfo->cinfo, COL_RES_DL_DST, "DTE");
col_set_str(pinfo->cinfo, COL_RES_DL_SRC, "DCE");
}
ti = proto_tree_add_protocol_format(tree, proto_v120, tvb, 0, -1, "V.120");
v120_tree = proto_item_add_subtree(ti, ett_v120);
tc = proto_tree_add_item(v120_tree, hf_v120_address, tvb, 0, 2, ENC_BIG_ENDIAN);
proto_item_append_text(tc, "LLI: %d C/R: %s",
((byte0 & 0xfc) << 5) | ((byte1 & 0xfe) >> 1),
byte0 & 0x02 ? "R" : "C");
address_tree = proto_item_add_subtree(tc, ett_v120_address);
proto_tree_add_item(address_tree, hf_v120_rc, tvb, 0, 2, ENC_BIG_ENDIAN);
proto_tree_add_item(address_tree, hf_v120_lli, tvb, 0, 2, ENC_BIG_ENDIAN);
proto_tree_add_item(address_tree, hf_v120_ea0, tvb, 0, 2, ENC_BIG_ENDIAN);
proto_tree_add_item(address_tree, hf_v120_ea1, tvb, 0, 2, ENC_BIG_ENDIAN);
control = dissect_xdlc_control(tvb, 2, pinfo, v120_tree, hf_v120_control,
ett_v120_control, &v120_cf_items, &v120_cf_items_ext,
NULL, NULL, is_response, true, false);
v120len = 2 + XDLC_CONTROL_LEN(control, true);
if (tvb_bytes_exist(tvb, v120len, 1))
v120len += dissect_v120_header(tvb, v120len, v120_tree);
proto_item_set_len(ti, v120len);
next_tvb = tvb_new_subset_remaining(tvb, v120len);
call_data_dissector(next_tvb, pinfo, v120_tree);
return tvb_captured_length(tvb);
}
static int
dissect_v120_header(tvbuff_t *tvb, int offset, proto_tree *tree)
{
int header_len;
uint8_t byte0;
proto_tree *h_tree;
proto_item *tc;
byte0 = tvb_get_uint8(tvb, offset);
if (byte0 & 0x80) {
header_len = 1;
tc = proto_tree_add_item(tree, hf_v120_header8, tvb, 0, 1, ENC_BIG_ENDIAN);
h_tree = proto_item_add_subtree(tc, ett_v120_header);
proto_tree_add_item(h_tree, hf_v120_header_ext8, tvb, 0, 1, ENC_NA);
proto_tree_add_item(h_tree, hf_v120_header_break8, tvb, 0, 1, ENC_NA);
proto_tree_add_item(h_tree, hf_v120_header_error_control8, tvb, 0, 1, ENC_BIG_ENDIAN);
proto_tree_add_item(h_tree, hf_v120_header_segb8, tvb, 0, 1, ENC_NA);
proto_tree_add_item(h_tree, hf_v120_header_segf8, tvb, 0, 1, ENC_NA);
} else {
header_len = 2;
tc = proto_tree_add_item(tree, hf_v120_header16, tvb, 0, 2, ENC_BIG_ENDIAN);
h_tree = proto_item_add_subtree(tc, ett_v120_header);
proto_tree_add_item(h_tree, hf_v120_header_ext16, tvb, 0, 2, ENC_BIG_ENDIAN);
proto_tree_add_item(h_tree, hf_v120_header_break16, tvb, 0, 2, ENC_BIG_ENDIAN);
proto_tree_add_item(h_tree, hf_v120_header_error_control16, tvb, 0, 2, ENC_BIG_ENDIAN);
proto_tree_add_item(h_tree, hf_v120_header_segb16, tvb, 0, 2, ENC_BIG_ENDIAN);
proto_tree_add_item(h_tree, hf_v120_header_segf16, tvb, 0, 2, ENC_BIG_ENDIAN);
proto_tree_add_item(h_tree, hf_v120_header_e, tvb, 0, 2, ENC_BIG_ENDIAN);
proto_tree_add_item(h_tree, hf_v120_header_dr, tvb, 0, 2, ENC_BIG_ENDIAN);
proto_tree_add_item(h_tree, hf_v120_header_sr, tvb, 0, 2, ENC_BIG_ENDIAN);
proto_tree_add_item(h_tree, hf_v120_header_rr, tvb, 0, 2, ENC_BIG_ENDIAN);
}
proto_item_append_text(tc, " B: %d F: %d",
byte0 & 0x02 ? 1:0, byte0 & 0x01 ? 1:0);
return header_len;
}
void
proto_register_v120(void)
{
static hf_register_info hf[] = {
{ &hf_v120_address,
{ "Link Address", "v120.address", FT_UINT16, BASE_HEX, NULL,
0x0, NULL, HFILL }},
{ &hf_v120_rc,
{ "R/C", "v120.rc", FT_BOOLEAN, 16, TFS(&tfs_response_command),
0x0002, NULL, HFILL }},
{ &hf_v120_lli,
{ "LLI", "v120.lli", FT_UINT16, BASE_HEX, NULL,
0xfefc, NULL, HFILL }},
{ &hf_v120_ea0,
{ "EA0", "v120.ea0", FT_BOOLEAN, 16, TFS(&tfs_error_ok),
0x0001, NULL, HFILL }},
{ &hf_v120_ea1,
{ "EA1", "v120.ea1", FT_BOOLEAN, 16, TFS(&tfs_ok_error),
0x0100, NULL, HFILL }},
{ &hf_v120_control,
{ "Control Field", "v120.control", FT_UINT16, BASE_HEX, NULL, 0x0,
NULL, HFILL }},
{ &hf_v120_n_r,
{ "N(R)", "v120.control.n_r", FT_UINT16, BASE_DEC,
NULL, XDLC_N_R_EXT_MASK, NULL, HFILL }},
{ &hf_v120_n_s,
{ "N(S)", "v120.control.n_s", FT_UINT16, BASE_DEC,
NULL, XDLC_N_S_EXT_MASK, NULL, HFILL }},
{ &hf_v120_p,
{ "Poll", "v120.control.p", FT_BOOLEAN, 8,
TFS(&tfs_set_notset), XDLC_P_F, NULL, HFILL }},
{ &hf_v120_p_ext,
{ "Poll", "v120.control.p", FT_BOOLEAN, 16,
TFS(&tfs_set_notset), XDLC_P_F_EXT, NULL, HFILL }},
{ &hf_v120_f,
{ "Final", "v120.control.f", FT_BOOLEAN, 8,
TFS(&tfs_set_notset), XDLC_P_F, NULL, HFILL }},
{ &hf_v120_f_ext,
{ "Final", "v120.control.f", FT_BOOLEAN, 16,
TFS(&tfs_set_notset), XDLC_P_F_EXT, NULL, HFILL }},
{ &hf_v120_s_ftype,
{ "Supervisory frame type", "v120.control.s_ftype", FT_UINT16, BASE_HEX,
VALS(stype_vals), XDLC_S_FTYPE_MASK, NULL, HFILL }},
{ &hf_v120_u_modifier_cmd,
{ "Command", "v120.control.u_modifier_cmd", FT_UINT8, BASE_HEX,
VALS(modifier_vals_cmd), XDLC_U_MODIFIER_MASK, NULL, HFILL }},
{ &hf_v120_u_modifier_resp,
{ "Response", "v120.control.u_modifier_resp", FT_UINT8, BASE_HEX,
VALS(modifier_vals_resp), XDLC_U_MODIFIER_MASK, NULL, HFILL }},
{ &hf_v120_ftype_i,
{ "Frame type", "v120.control.ftype", FT_UINT16, BASE_HEX,
VALS(ftype_vals), XDLC_I_MASK, NULL, HFILL }},
{ &hf_v120_ftype_s_u,
{ "Frame type", "v120.control.ftype", FT_UINT8, BASE_HEX,
VALS(ftype_vals), XDLC_S_U_MASK, NULL, HFILL }},
{ &hf_v120_ftype_s_u_ext,
{ "Frame type", "v120.control.ftype", FT_UINT16, BASE_HEX,
VALS(ftype_vals), XDLC_S_U_MASK, NULL, HFILL }},
{ &hf_v120_header8,
{ "Header", "v120.header", FT_UINT8, BASE_HEX, NULL, 0x0,
NULL, HFILL }},
{ &hf_v120_header_ext8,
{ "Extension octet", "v120.header.ext", FT_BOOLEAN, 8, TFS(&tfs_yes_no), 0x80,
NULL, HFILL }},
{ &hf_v120_header_break8,
{ "Break condition", "v120.header.break", FT_BOOLEAN, 8, TFS(&tfs_yes_no), 0x40,
NULL, HFILL }},
{ &hf_v120_header_error_control8,
{ "Error control C1/C2", "v120.error_control", FT_UINT8, BASE_HEX, NULL, 0x0C,
NULL, HFILL }},
{ &hf_v120_header_segb8,
{ "Bit B", "v120.header.segb", FT_BOOLEAN, 8, TFS(&tfs_segmentation_no_segmentation), 0x02,
NULL, HFILL }},
{ &hf_v120_header_segf8,
{ "Bit F", "v120.header.segf", FT_BOOLEAN, 8, TFS(&tfs_segmentation_no_segmentation), 0x01,
NULL, HFILL }},
{ &hf_v120_header16,
{ "Header", "v120.header", FT_UINT16, BASE_HEX, NULL, 0x0,
NULL, HFILL }},
{ &hf_v120_header_ext16,
{ "Extension octet", "v120.header.ext", FT_BOOLEAN, 16, TFS(&tfs_yes_no), 0x0080,
NULL, HFILL }},
{ &hf_v120_header_break16,
{ "Break condition", "v120.header.break", FT_BOOLEAN, 16, TFS(&tfs_yes_no), 0x0040,
NULL, HFILL }},
{ &hf_v120_header_error_control16,
{ "Error control C1/C2", "v120.error_control", FT_UINT16, BASE_HEX, NULL, 0x0C,
NULL, HFILL }},
{ &hf_v120_header_segb16,
{ "Bit B", "v120.header.segb", FT_BOOLEAN, 16, TFS(&tfs_segmentation_no_segmentation), 0x0002,
NULL, HFILL }},
{ &hf_v120_header_segf16,
{ "Bit F", "v120.header.segf", FT_BOOLEAN, 16, TFS(&tfs_segmentation_no_segmentation), 0x0001,
NULL, HFILL }},
{ &hf_v120_header_e,
{ "E", "v120.header.e", FT_BOOLEAN, 16, TFS(&tfs_yes_no), 0x8000,
NULL, HFILL }},
{ &hf_v120_header_dr,
{ "DR", "v120.header.dr", FT_BOOLEAN, 16, TFS(&tfs_yes_no), 0x4000,
NULL, HFILL }},
{ &hf_v120_header_sr,
{ "SR", "v120.header.sr", FT_BOOLEAN, 16, TFS(&tfs_yes_no), 0x2000,
NULL, HFILL }},
{ &hf_v120_header_rr,
{ "RR", "v120.header.rr", FT_BOOLEAN, 16, TFS(&tfs_yes_no), 0x1000,
NULL, HFILL }},
};
static int *ett[] = {
&ett_v120,
&ett_v120_address,
&ett_v120_control,
&ett_v120_header,
};
proto_v120 = proto_register_protocol("Async data over ISDN (V.120)",
"V.120", "v120");
proto_register_field_array (proto_v120, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
register_dissector("v120", dissect_v120, proto_v120);
}
/*
* 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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