2 * Routines for v120 frame disassembly
3 * Bert Driehuis <driehuis@playbeing.org>
5 * $Id: packet-v120.c,v 1.3 1999/12/14 06:21:19 guy Exp $
7 * Ethereal - Network traffic analyzer
8 * By Gerald Combs <gerald@zing.org>
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License
14 * as published by the Free Software Foundation; either version 2
15 * of the License, or (at your option) any later version.
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
22 * You should have received a copy of the GNU General Public License
23 * along with this program; if not, write to the Free Software
24 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
31 #ifdef HAVE_SYS_TYPES_H
32 # include <sys/types.h>
43 static int proto_v120 = -1;
44 static int hf_v120_address = -1;
45 static int hf_v120_control = -1;
46 static int hf_v120_header = -1;
48 static gint ett_v120 = -1;
49 static gint ett_v120_address = -1;
50 static gint ett_v120_control = -1;
51 static gint ett_v120_header = -1;
53 void dissect_v120_header(const u_char *pd, int offset, frame_data *fd, proto_tree *tree);
56 dissect_v120(const u_char *pd, frame_data *fd, proto_tree *tree)
58 proto_tree *v120_tree, *ti, *tc, *address_tree;
64 if (check_col(fd, COL_PROTOCOL))
65 col_add_str(fd, COL_PROTOCOL, "V.120");
67 if(check_col(fd, COL_RES_DL_SRC))
68 col_add_fstr(fd, COL_RES_DL_SRC, "0x%02X", pd[0]);
69 if ((pd[0] & 0x01) != 0x00 && (pd[1] && 0x01) != 0x01)
71 if (check_col(fd, COL_INFO))
72 col_add_str(fd, COL_INFO, "Invalid V.120 frame");
74 ti = proto_tree_add_item_format(tree, proto_v120, 0, fd->cap_len,
75 NULL, "Invalid V.120 frame");
79 if (fd->pseudo_header.x25.flags & FROM_DCE) {
80 if(check_col(fd, COL_RES_DL_DST))
81 col_add_str(fd, COL_RES_DL_DST, "DTE");
82 if(check_col(fd, COL_RES_DL_SRC))
83 col_add_str(fd, COL_RES_DL_SRC, "DCE");
86 if(check_col(fd, COL_RES_DL_DST))
87 col_add_str(fd, COL_RES_DL_DST, "DCE");
88 if(check_col(fd, COL_RES_DL_SRC))
89 col_add_str(fd, COL_RES_DL_SRC, "DTE");
92 if (((fd->pseudo_header.x25.flags & FROM_DCE) && pd[0] & 0x02) ||
93 (!(fd->pseudo_header.x25.flags & FROM_DCE) && !(pd[0] & 0x02)))
99 v120len = fd->pkt_len;
103 ti = proto_tree_add_item_format(tree, proto_v120, 0, v120len, NULL,
105 v120_tree = proto_item_add_subtree(ti, ett_v120);
106 addr = pd[1] << 8 | pd[0];
107 sprintf(info, "LLI: %d C/R: %s",
108 ((pd[0] & 0xfc) << 5) | ((pd[1] & 0xfe) >> 1),
109 pd[0] & 0x02 ? "R" : "C");
110 tc = proto_tree_add_item_format(v120_tree, ett_v120_address,
112 "Address field: %s", info);
113 address_tree = proto_item_add_subtree(tc, ett_v120_address);
114 proto_tree_add_text(address_tree, 0, 2,
115 decode_boolean_bitfield(addr, 0x0002, 2*8,
116 "Response", "Command"), NULL);
117 sprintf(info, "LLI: %d", ((pd[0] & 0xfc) << 5) | ((pd[1] & 0xfe) >> 1));
118 proto_tree_add_text(address_tree, 0, 2,
119 decode_numeric_bitfield(addr, 0xfefc, 2*8, info));
120 proto_tree_add_text(address_tree, 0, 2,
121 decode_boolean_bitfield(addr, 0x0001, 2*8,
122 "EA0 = 1 (Error)", "EA0 = 0"), NULL);
123 proto_tree_add_text(address_tree, 0, 2,
124 decode_boolean_bitfield(addr, 0x0100, 2*8,
125 "EA1 = 1", "EA1 = 0 (Error)"), NULL);
127 dissect_v120_header(pd, 4, fd, v120_tree);
131 dissect_xdlc_control(pd, 2, fd, v120_tree, hf_v120_control,
132 ett_v120_control, is_response, v120len == 3 ? FALSE : TRUE);
136 dissect_v120_header(const u_char *pd, int offset, frame_data *fd, proto_tree *tree)
139 int header_len, nbits;
141 proto_tree *h_tree, *tc;
143 if (pd[offset] & 0x80) {
148 header = pd[offset] | pd[offset + 1] << 8;
150 nbits = header_len * 8;
151 sprintf(info, "Header: B: %d F: %d", pd[offset] & 0x02 ? 1:0,
152 pd[offset] & 0x01 ? 1:0);
153 tc = proto_tree_add_item_format(tree, ett_v120_header,
155 "Header octet: %s (0x%02X)", info, pd[offset]);
156 h_tree = proto_item_add_subtree(tc, ett_v120_header);
157 proto_tree_add_text(h_tree, offset, header_len,
158 decode_boolean_bitfield(header, 0x80, nbits,
159 "No extension octet", "Extension octet follows"), NULL);
160 proto_tree_add_text(h_tree, offset, header_len,
161 decode_boolean_bitfield(header, 0x40, nbits,
162 "Break condition", "No break condition"), NULL);
163 sprintf(info, "Error control C1/C2: %d", (header & 0x0c) >> 2);
164 proto_tree_add_text(h_tree, offset, header_len,
165 decode_numeric_bitfield(header, 0x0c, nbits, info));
166 proto_tree_add_text(h_tree, offset, header_len,
167 decode_boolean_bitfield(header, 0x02, nbits,
168 "Segmentation bit B", "No segmentation bit B"), NULL);
169 proto_tree_add_text(h_tree, offset, header_len,
170 decode_boolean_bitfield(header, 0x01, nbits,
171 "Segmentation bit F", "No segmentation bit F"), NULL);
172 if (header_len == 2) {
173 proto_tree_add_text(h_tree, offset, header_len,
174 decode_boolean_bitfield(header, 0x8000, nbits,
175 "E", "E bit not set (Error)"), NULL);
176 proto_tree_add_text(h_tree, offset, header_len,
177 decode_boolean_bitfield(header, 0x4000, nbits,
178 "DR", "No DR"), NULL);
179 proto_tree_add_text(h_tree, offset, header_len,
180 decode_boolean_bitfield(header, 0x2000, nbits,
181 "SR", "No SR"), NULL);
182 proto_tree_add_text(h_tree, offset, header_len,
183 decode_boolean_bitfield(header, 0x1000, nbits,
184 "RR", "No RR"), NULL);
188 proto_register_v120(void)
190 static hf_register_info hf[] = {
192 { "Link Address", "v120.address", FT_UINT16, BASE_HEX, NULL,
195 { "Control Field", "v120.control", FT_STRING, BASE_NONE, NULL, 0x0,
198 { "Header Field", "v120.header", FT_STRING, BASE_NONE, NULL, 0x0,
201 static gint *ett[] = {
208 proto_v120 = proto_register_protocol ("Async data over ISDN (V.120)", "v120");
209 proto_register_field_array (proto_v120, hf, array_length(hf));
210 proto_register_subtree_array(ett, array_length(ett));