wireshark/packet-v120.c

212 lines
6.7 KiB
C

/* packet-v120.c
* Routines for v120 frame disassembly
* Bert Driehuis <driehuis@playbeing.org>
*
* $Id: packet-v120.c,v 1.3 1999/12/14 06:21:19 guy Exp $
*
* Ethereal - Network traffic analyzer
* By Gerald Combs <gerald@zing.org>
* Copyright 1998
*
*
* 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#ifdef HAVE_SYS_TYPES_H
# include <sys/types.h>
#endif
#include <stdio.h>
#include <glib.h>
#include <string.h>
#include "packet.h"
#include "xdlc.h"
#define FROM_DCE 0x80
static int proto_v120 = -1;
static int hf_v120_address = -1;
static int hf_v120_control = -1;
static int hf_v120_header = -1;
static gint ett_v120 = -1;
static gint ett_v120_address = -1;
static gint ett_v120_control = -1;
static gint ett_v120_header = -1;
void dissect_v120_header(const u_char *pd, int offset, frame_data *fd, proto_tree *tree);
void
dissect_v120(const u_char *pd, frame_data *fd, proto_tree *tree)
{
proto_tree *v120_tree, *ti, *tc, *address_tree;
int is_response;
int addr;
char info[80];
int v120len;
if (check_col(fd, COL_PROTOCOL))
col_add_str(fd, COL_PROTOCOL, "V.120");
if(check_col(fd, COL_RES_DL_SRC))
col_add_fstr(fd, COL_RES_DL_SRC, "0x%02X", pd[0]);
if ((pd[0] & 0x01) != 0x00 && (pd[1] && 0x01) != 0x01)
{
if (check_col(fd, COL_INFO))
col_add_str(fd, COL_INFO, "Invalid V.120 frame");
if (tree)
ti = proto_tree_add_item_format(tree, proto_v120, 0, fd->cap_len,
NULL, "Invalid V.120 frame");
return;
}
if (fd->pseudo_header.x25.flags & FROM_DCE) {
if(check_col(fd, COL_RES_DL_DST))
col_add_str(fd, COL_RES_DL_DST, "DTE");
if(check_col(fd, COL_RES_DL_SRC))
col_add_str(fd, COL_RES_DL_SRC, "DCE");
}
else {
if(check_col(fd, COL_RES_DL_DST))
col_add_str(fd, COL_RES_DL_DST, "DCE");
if(check_col(fd, COL_RES_DL_SRC))
col_add_str(fd, COL_RES_DL_SRC, "DTE");
}
if (((fd->pseudo_header.x25.flags & FROM_DCE) && pd[0] & 0x02) ||
(!(fd->pseudo_header.x25.flags & FROM_DCE) && !(pd[0] & 0x02)))
is_response = TRUE;
else
is_response = FALSE;
if (fd->pkt_len <= 5)
v120len = fd->pkt_len;
else
v120len = 5;
if (tree) {
ti = proto_tree_add_item_format(tree, proto_v120, 0, v120len, NULL,
"V.120");
v120_tree = proto_item_add_subtree(ti, ett_v120);
addr = pd[1] << 8 | pd[0];
sprintf(info, "LLI: %d C/R: %s",
((pd[0] & 0xfc) << 5) | ((pd[1] & 0xfe) >> 1),
pd[0] & 0x02 ? "R" : "C");
tc = proto_tree_add_item_format(v120_tree, ett_v120_address,
0, 2,
"Address field: %s", info);
address_tree = proto_item_add_subtree(tc, ett_v120_address);
proto_tree_add_text(address_tree, 0, 2,
decode_boolean_bitfield(addr, 0x0002, 2*8,
"Response", "Command"), NULL);
sprintf(info, "LLI: %d", ((pd[0] & 0xfc) << 5) | ((pd[1] & 0xfe) >> 1));
proto_tree_add_text(address_tree, 0, 2,
decode_numeric_bitfield(addr, 0xfefc, 2*8, info));
proto_tree_add_text(address_tree, 0, 2,
decode_boolean_bitfield(addr, 0x0001, 2*8,
"EA0 = 1 (Error)", "EA0 = 0"), NULL);
proto_tree_add_text(address_tree, 0, 2,
decode_boolean_bitfield(addr, 0x0100, 2*8,
"EA1 = 1", "EA1 = 0 (Error)"), NULL);
if (v120len == 5)
dissect_v120_header(pd, 4, fd, v120_tree);
}
else
v120_tree = NULL;
dissect_xdlc_control(pd, 2, fd, v120_tree, hf_v120_control,
ett_v120_control, is_response, v120len == 3 ? FALSE : TRUE);
}
void
dissect_v120_header(const u_char *pd, int offset, frame_data *fd, proto_tree *tree)
{
char info[80];
int header_len, nbits;
int header;
proto_tree *h_tree, *tc;
if (pd[offset] & 0x80) {
header_len = 1;
header = pd[offset];
} else {
header_len = 2;
header = pd[offset] | pd[offset + 1] << 8;
}
nbits = header_len * 8;
sprintf(info, "Header: B: %d F: %d", pd[offset] & 0x02 ? 1:0,
pd[offset] & 0x01 ? 1:0);
tc = proto_tree_add_item_format(tree, ett_v120_header,
offset, header_len,
"Header octet: %s (0x%02X)", info, pd[offset]);
h_tree = proto_item_add_subtree(tc, ett_v120_header);
proto_tree_add_text(h_tree, offset, header_len,
decode_boolean_bitfield(header, 0x80, nbits,
"No extension octet", "Extension octet follows"), NULL);
proto_tree_add_text(h_tree, offset, header_len,
decode_boolean_bitfield(header, 0x40, nbits,
"Break condition", "No break condition"), NULL);
sprintf(info, "Error control C1/C2: %d", (header & 0x0c) >> 2);
proto_tree_add_text(h_tree, offset, header_len,
decode_numeric_bitfield(header, 0x0c, nbits, info));
proto_tree_add_text(h_tree, offset, header_len,
decode_boolean_bitfield(header, 0x02, nbits,
"Segmentation bit B", "No segmentation bit B"), NULL);
proto_tree_add_text(h_tree, offset, header_len,
decode_boolean_bitfield(header, 0x01, nbits,
"Segmentation bit F", "No segmentation bit F"), NULL);
if (header_len == 2) {
proto_tree_add_text(h_tree, offset, header_len,
decode_boolean_bitfield(header, 0x8000, nbits,
"E", "E bit not set (Error)"), NULL);
proto_tree_add_text(h_tree, offset, header_len,
decode_boolean_bitfield(header, 0x4000, nbits,
"DR", "No DR"), NULL);
proto_tree_add_text(h_tree, offset, header_len,
decode_boolean_bitfield(header, 0x2000, nbits,
"SR", "No SR"), NULL);
proto_tree_add_text(h_tree, offset, header_len,
decode_boolean_bitfield(header, 0x1000, nbits,
"RR", "No RR"), NULL);
}
}
void
proto_register_v120(void)
{
static hf_register_info hf[] = {
{ &hf_v120_address,
{ "Link Address", "v120.address", FT_UINT16, BASE_HEX, NULL,
0x0, "" }},
{ &hf_v120_control,
{ "Control Field", "v120.control", FT_STRING, BASE_NONE, NULL, 0x0,
"" }},
{ &hf_v120_header,
{ "Header Field", "v120.header", FT_STRING, BASE_NONE, NULL, 0x0,
"" }},
};
static gint *ett[] = {
&ett_v120,
&ett_v120_address,
&ett_v120_control,
&ett_v120_header,
};
proto_v120 = proto_register_protocol ("Async data over ISDN (V.120)", "v120");
proto_register_field_array (proto_v120, hf, array_length(hf));
proto_register_subtree_array(ett, array_length(ett));
}