2 * Routines for v120 frame disassembly
3 * Bert Driehuis <driehuis@playbeing.org>
5 * $Id: packet-v120.c,v 1.33 2004/01/18 08:32:46 guy Exp $
7 * Ethereal - Network traffic analyzer
8 * By Gerald Combs <gerald@ethereal.com>
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License
13 * as published by the Free Software Foundation; either version 2
14 * of the License, or (at your option) any later version.
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
33 #include <epan/packet.h>
36 static int proto_v120 = -1;
37 static int hf_v120_address = -1;
38 static int hf_v120_control = -1;
39 static int hf_v120_n_r = -1;
40 static int hf_v120_n_s = -1;
41 static int hf_v120_p = -1;
42 static int hf_v120_p_ext = -1;
43 static int hf_v120_f = -1;
44 static int hf_v120_f_ext = -1;
45 static int hf_v120_s_ftype = -1;
46 static int hf_v120_u_modifier_cmd = -1;
47 static int hf_v120_u_modifier_resp = -1;
48 static int hf_v120_ftype_i = -1;
49 static int hf_v120_ftype_s_u = -1;
50 static int hf_v120_ftype_s_u_ext = -1;
51 static int hf_v120_header = -1;
53 static gint ett_v120 = -1;
54 static gint ett_v120_address = -1;
55 static gint ett_v120_control = -1;
56 static gint ett_v120_header = -1;
58 static dissector_handle_t data_handle;
60 static int dissect_v120_header(tvbuff_t *tvb, int offset, proto_tree *tree);
62 /* Used only for U frames */
63 static const xdlc_cf_items v120_cf_items = {
69 &hf_v120_u_modifier_cmd,
70 &hf_v120_u_modifier_resp,
75 /* Used only for I and S frames */
76 static const xdlc_cf_items v120_cf_items_ext = {
85 &hf_v120_ftype_s_u_ext
89 dissect_v120(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
91 proto_tree *v120_tree, *tc, *address_tree;
101 if (check_col(pinfo->cinfo, COL_PROTOCOL))
102 col_set_str(pinfo->cinfo, COL_PROTOCOL, "V.120");
103 if (check_col(pinfo->cinfo, COL_INFO))
104 col_clear(pinfo->cinfo, COL_INFO);
106 byte0 = tvb_get_guint8(tvb, 0);
108 if(check_col(pinfo->cinfo, COL_RES_DL_SRC))
109 col_add_fstr(pinfo->cinfo, COL_RES_DL_SRC, "0x%02X", byte0);
111 byte1 = tvb_get_guint8(tvb, 1);
113 if ((byte0 & 0x01) != 0x00 && (byte1 && 0x01) != 0x01)
115 if (check_col(pinfo->cinfo, COL_INFO))
116 col_set_str(pinfo->cinfo, COL_INFO, "Invalid V.120 frame");
118 ti = proto_tree_add_protocol_format(tree, proto_v120, tvb, 0, -1,
119 "Invalid V.120 frame");
123 if (pinfo->p2p_dir == P2P_DIR_SENT) {
124 is_response = (byte0 & 0x02) ? FALSE: TRUE;
125 if(check_col(pinfo->cinfo, COL_RES_DL_DST))
126 col_set_str(pinfo->cinfo, COL_RES_DL_DST, "DCE");
127 if(check_col(pinfo->cinfo, COL_RES_DL_SRC))
128 col_set_str(pinfo->cinfo, COL_RES_DL_SRC, "DTE");
130 /* XXX - what if the direction is unknown? */
131 is_response = (byte0 & 0x02) ? TRUE : FALSE;
132 if(check_col(pinfo->cinfo, COL_RES_DL_DST))
133 col_set_str(pinfo->cinfo, COL_RES_DL_DST, "DTE");
134 if(check_col(pinfo->cinfo, COL_RES_DL_SRC))
135 col_set_str(pinfo->cinfo, COL_RES_DL_SRC, "DCE");
139 ti = proto_tree_add_protocol_format(tree, proto_v120, tvb, 0, -1, "V.120");
140 v120_tree = proto_item_add_subtree(ti, ett_v120);
141 addr = byte1 << 8 | byte0;
142 sprintf(info, "LLI: %d C/R: %s",
143 ((byte0 & 0xfc) << 5) | ((byte1 & 0xfe) >> 1),
144 byte0 & 0x02 ? "R" : "C");
145 tc = proto_tree_add_text(v120_tree, tvb,
147 "Address field: %s", info);
148 address_tree = proto_item_add_subtree(tc, ett_v120_address);
149 proto_tree_add_text(address_tree, tvb, 0, 2,
150 decode_boolean_bitfield(addr, 0x0002, 2*8,
151 "Response", "Command"), NULL);
152 sprintf(info, "LLI: %d", ((byte0 & 0xfc) << 5) | ((byte1 & 0xfe) >> 1));
153 proto_tree_add_text(address_tree, tvb, 0, 2,
154 decode_numeric_bitfield(addr, 0xfefc, 2*8, info));
155 proto_tree_add_text(address_tree, tvb, 0, 2,
156 decode_boolean_bitfield(addr, 0x0001, 2*8,
157 "EA0 = 1 (Error)", "EA0 = 0"), NULL);
158 proto_tree_add_text(address_tree, tvb, 0, 2,
159 decode_boolean_bitfield(addr, 0x0100, 2*8,
160 "EA1 = 1", "EA1 = 0 (Error)"), NULL);
166 control = dissect_xdlc_control(tvb, 2, pinfo, v120_tree, hf_v120_control,
167 ett_v120_control, &v120_cf_items, &v120_cf_items_ext,
168 NULL, NULL, is_response, TRUE, FALSE);
170 v120len = 2 + XDLC_CONTROL_LEN(control, TRUE);
171 if (tvb_bytes_exist(tvb, v120len, 1))
172 v120len += dissect_v120_header(tvb, v120len, v120_tree);
173 proto_item_set_len(ti, v120len);
174 next_tvb = tvb_new_subset(tvb, v120len, -1, -1);
175 call_dissector(data_handle,next_tvb, pinfo, v120_tree);
180 dissect_v120_header(tvbuff_t *tvb, int offset, proto_tree *tree)
183 int header_len, nbits;
185 proto_tree *h_tree, *tc;
188 byte0 = tvb_get_guint8(tvb, offset);
195 header = byte0 | tvb_get_guint8(tvb, offset + 1) << 8;
197 nbits = header_len * 8;
198 sprintf(info, "Header: B: %d F: %d", byte0 & 0x02 ? 1:0,
200 tc = proto_tree_add_text(tree, tvb,
202 "Header octet: %s (0x%02X)", info, byte0);
203 h_tree = proto_item_add_subtree(tc, ett_v120_header);
204 proto_tree_add_text(h_tree, tvb, offset, header_len,
205 decode_boolean_bitfield(header, 0x80, nbits,
206 "No extension octet", "Extension octet follows"), NULL);
207 proto_tree_add_text(h_tree, tvb, offset, header_len,
208 decode_boolean_bitfield(header, 0x40, nbits,
209 "Break condition", "No break condition"), NULL);
210 sprintf(info, "Error control C1/C2: %d", (header & 0x0c) >> 2);
211 proto_tree_add_text(h_tree, tvb, offset, header_len,
212 decode_numeric_bitfield(header, 0x0c, nbits, info));
213 proto_tree_add_text(h_tree, tvb, offset, header_len,
214 decode_boolean_bitfield(header, 0x02, nbits,
215 "Segmentation bit B", "No segmentation bit B"), NULL);
216 proto_tree_add_text(h_tree, tvb, offset, header_len,
217 decode_boolean_bitfield(header, 0x01, nbits,
218 "Segmentation bit F", "No segmentation bit F"), NULL);
219 if (header_len == 2) {
220 proto_tree_add_text(h_tree, tvb, offset, header_len,
221 decode_boolean_bitfield(header, 0x8000, nbits,
222 "E", "E bit not set (Error)"), NULL);
223 proto_tree_add_text(h_tree, tvb, offset, header_len,
224 decode_boolean_bitfield(header, 0x4000, nbits,
225 "DR", "No DR"), NULL);
226 proto_tree_add_text(h_tree, tvb, offset, header_len,
227 decode_boolean_bitfield(header, 0x2000, nbits,
228 "SR", "No SR"), NULL);
229 proto_tree_add_text(h_tree, tvb, offset, header_len,
230 decode_boolean_bitfield(header, 0x1000, nbits,
231 "RR", "No RR"), NULL);
237 proto_register_v120(void)
239 static hf_register_info hf[] = {
241 { "Link Address", "v120.address", FT_UINT16, BASE_HEX, NULL,
244 { "Control Field", "v120.control", FT_UINT16, BASE_HEX, NULL, 0x0,
247 { "N(R)", "v120.control.n_r", FT_UINT16, BASE_DEC,
248 NULL, XDLC_N_R_EXT_MASK, "", HFILL }},
250 { "N(S)", "v120.control.n_s", FT_UINT16, BASE_DEC,
251 NULL, XDLC_N_S_EXT_MASK, "", HFILL }},
253 { "Poll", "v120.control.p", FT_BOOLEAN, 8,
254 TFS(&flags_set_truth), XDLC_P_F, "", HFILL }},
256 { "Poll", "v120.control.p", FT_BOOLEAN, 16,
257 TFS(&flags_set_truth), XDLC_P_F_EXT, "", HFILL }},
259 { "Final", "v120.control.f", FT_BOOLEAN, 8,
260 TFS(&flags_set_truth), XDLC_P_F, "", HFILL }},
262 { "Final", "v120.control.f", FT_BOOLEAN, 16,
263 TFS(&flags_set_truth), XDLC_P_F_EXT, "", HFILL }},
265 { "Supervisory frame type", "v120.control.s_ftype", FT_UINT16, BASE_HEX,
266 VALS(stype_vals), XDLC_S_FTYPE_MASK, "", HFILL }},
267 { &hf_v120_u_modifier_cmd,
268 { "Command", "v120.control.u_modifier_cmd", FT_UINT8, BASE_HEX,
269 VALS(modifier_vals_cmd), XDLC_U_MODIFIER_MASK, "", HFILL }},
270 { &hf_v120_u_modifier_resp,
271 { "Response", "v120.control.u_modifier_resp", FT_UINT8, BASE_HEX,
272 VALS(modifier_vals_resp), XDLC_U_MODIFIER_MASK, "", HFILL }},
274 { "Frame type", "v120.control.ftype", FT_UINT16, BASE_HEX,
275 VALS(ftype_vals), XDLC_I_MASK, "", HFILL }},
276 { &hf_v120_ftype_s_u,
277 { "Frame type", "v120.control.ftype", FT_UINT8, BASE_HEX,
278 VALS(ftype_vals), XDLC_S_U_MASK, "", HFILL }},
279 { &hf_v120_ftype_s_u_ext,
280 { "Frame type", "v120.control.ftype", FT_UINT16, BASE_HEX,
281 VALS(ftype_vals), XDLC_S_U_MASK, "", HFILL }},
283 { "Header Field", "v120.header", FT_STRING, BASE_NONE, NULL, 0x0,
286 static gint *ett[] = {
293 proto_v120 = proto_register_protocol("Async data over ISDN (V.120)",
295 proto_register_field_array (proto_v120, hf, array_length(hf));
296 proto_register_subtree_array(ett, array_length(ett));
298 register_dissector("v120", dissect_v120, proto_v120);
302 proto_reg_handoff_v120(void)
304 data_handle = find_dissector("data");