forked from osmocom/wireshark
239 lines
7.4 KiB
C
239 lines
7.4 KiB
C
/* packet-v120.c
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* Routines for v120 frame disassembly
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* Bert Driehuis <driehuis@playbeing.org>
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*
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* $Id: packet-v120.c,v 1.19 2001/06/18 02:17:53 guy Exp $
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*
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* Ethereal - Network traffic analyzer
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* By Gerald Combs <gerald@zing.org>
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* Copyright 1998
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*
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*/
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#ifdef HAVE_CONFIG_H
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# include "config.h"
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#endif
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#ifdef HAVE_SYS_TYPES_H
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# include <sys/types.h>
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#endif
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#include <stdio.h>
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#include <glib.h>
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#include <string.h>
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#include "packet.h"
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#include "xdlc.h"
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#define FROM_DCE 0x80
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static int proto_v120 = -1;
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static int hf_v120_address = -1;
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static int hf_v120_control = -1;
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static int hf_v120_header = -1;
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static gint ett_v120 = -1;
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static gint ett_v120_address = -1;
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static gint ett_v120_control = -1;
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static gint ett_v120_header = -1;
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static int dissect_v120_header(tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree);
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static void
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dissect_v120(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
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{
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proto_tree *v120_tree, *tc, *address_tree;
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proto_item *ti;
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int is_response;
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int addr;
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char info[80];
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int v120len;
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guint8 byte0, byte1;
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guint16 control;
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tvbuff_t *next_tvb;
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if (check_col(pinfo->fd, COL_PROTOCOL))
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col_set_str(pinfo->fd, COL_PROTOCOL, "V.120");
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if (check_col(pinfo->fd, COL_INFO))
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col_clear(pinfo->fd, COL_INFO);
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byte0 = tvb_get_guint8(tvb, 0);
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if(check_col(pinfo->fd, COL_RES_DL_SRC))
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col_add_fstr(pinfo->fd, COL_RES_DL_SRC, "0x%02X", byte0);
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byte1 = tvb_get_guint8(tvb, 1);
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if ((byte0 & 0x01) != 0x00 && (byte1 && 0x01) != 0x01)
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{
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if (check_col(pinfo->fd, COL_INFO))
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col_set_str(pinfo->fd, COL_INFO, "Invalid V.120 frame");
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if (tree)
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ti = proto_tree_add_protocol_format(tree, proto_v120, tvb, 0, tvb_length(tvb),
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"Invalid V.120 frame");
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return;
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}
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if (pinfo->pseudo_header->x25.flags & FROM_DCE) {
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if(check_col(pinfo->fd, COL_RES_DL_DST))
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col_set_str(pinfo->fd, COL_RES_DL_DST, "DTE");
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if(check_col(pinfo->fd, COL_RES_DL_SRC))
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col_set_str(pinfo->fd, COL_RES_DL_SRC, "DCE");
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}
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else {
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if(check_col(pinfo->fd, COL_RES_DL_DST))
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col_set_str(pinfo->fd, COL_RES_DL_DST, "DCE");
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if(check_col(pinfo->fd, COL_RES_DL_SRC))
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col_set_str(pinfo->fd, COL_RES_DL_SRC, "DTE");
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}
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if (((pinfo->pseudo_header->x25.flags & FROM_DCE) && byte0 & 0x02) ||
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(!(pinfo->pseudo_header->x25.flags & FROM_DCE) && !(byte0 & 0x02)))
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is_response = TRUE;
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else
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is_response = FALSE;
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if (tree) {
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ti = proto_tree_add_protocol_format(tree, proto_v120, tvb, 0, 0, "V.120");
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v120_tree = proto_item_add_subtree(ti, ett_v120);
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addr = byte1 << 8 | byte0;
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sprintf(info, "LLI: %d C/R: %s",
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((byte0 & 0xfc) << 5) | ((byte1 & 0xfe) >> 1),
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byte0 & 0x02 ? "R" : "C");
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tc = proto_tree_add_text(v120_tree, tvb,
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0, 2,
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"Address field: %s", info);
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address_tree = proto_item_add_subtree(tc, ett_v120_address);
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proto_tree_add_text(address_tree, tvb, 0, 2,
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decode_boolean_bitfield(addr, 0x0002, 2*8,
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"Response", "Command"), NULL);
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sprintf(info, "LLI: %d", ((byte0 & 0xfc) << 5) | ((byte1 & 0xfe) >> 1));
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proto_tree_add_text(address_tree, tvb, 0, 2,
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decode_numeric_bitfield(addr, 0xfefc, 2*8, info));
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proto_tree_add_text(address_tree, tvb, 0, 2,
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decode_boolean_bitfield(addr, 0x0001, 2*8,
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"EA0 = 1 (Error)", "EA0 = 0"), NULL);
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proto_tree_add_text(address_tree, tvb, 0, 2,
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decode_boolean_bitfield(addr, 0x0100, 2*8,
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"EA1 = 1", "EA1 = 0 (Error)"), NULL);
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}
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else {
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v120_tree = NULL;
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ti = NULL;
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}
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control = dissect_xdlc_control(tvb, 2, pinfo, v120_tree, hf_v120_control,
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ett_v120_control, is_response, TRUE);
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if (tree) {
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v120len = 2 + XDLC_CONTROL_LEN(control, TRUE);
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if (tvb_bytes_exist(tvb, v120len, 1))
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v120len += dissect_v120_header(tvb, v120len, pinfo, v120_tree);
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proto_item_set_len(ti, v120len);
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next_tvb = tvb_new_subset(tvb, v120len, -1, -1);
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dissect_data(next_tvb, 0, pinfo, v120_tree);
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}
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}
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static int
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dissect_v120_header(tvbuff_t *tvb, int offset, packet_info *pinfo, proto_tree *tree)
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{
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char info[80];
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int header_len, nbits;
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int header;
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proto_tree *h_tree, *tc;
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guint8 byte0;
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byte0 = tvb_get_guint8(tvb, offset);
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if (byte0 & 0x80) {
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header_len = 1;
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header = byte0;
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} else {
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header_len = 2;
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header = byte0 | tvb_get_guint8(tvb, offset + 1) << 8;
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}
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nbits = header_len * 8;
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sprintf(info, "Header: B: %d F: %d", byte0 & 0x02 ? 1:0,
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byte0 & 0x01 ? 1:0);
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tc = proto_tree_add_text(tree, tvb,
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offset, header_len,
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"Header octet: %s (0x%02X)", info, byte0);
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h_tree = proto_item_add_subtree(tc, ett_v120_header);
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proto_tree_add_text(h_tree, tvb, offset, header_len,
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decode_boolean_bitfield(header, 0x80, nbits,
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"No extension octet", "Extension octet follows"), NULL);
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proto_tree_add_text(h_tree, tvb, offset, header_len,
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decode_boolean_bitfield(header, 0x40, nbits,
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"Break condition", "No break condition"), NULL);
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sprintf(info, "Error control C1/C2: %d", (header & 0x0c) >> 2);
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proto_tree_add_text(h_tree, tvb, offset, header_len,
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decode_numeric_bitfield(header, 0x0c, nbits, info));
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proto_tree_add_text(h_tree, tvb, offset, header_len,
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decode_boolean_bitfield(header, 0x02, nbits,
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"Segmentation bit B", "No segmentation bit B"), NULL);
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proto_tree_add_text(h_tree, tvb, offset, header_len,
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decode_boolean_bitfield(header, 0x01, nbits,
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"Segmentation bit F", "No segmentation bit F"), NULL);
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if (header_len == 2) {
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proto_tree_add_text(h_tree, tvb, offset, header_len,
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decode_boolean_bitfield(header, 0x8000, nbits,
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"E", "E bit not set (Error)"), NULL);
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proto_tree_add_text(h_tree, tvb, offset, header_len,
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decode_boolean_bitfield(header, 0x4000, nbits,
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"DR", "No DR"), NULL);
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proto_tree_add_text(h_tree, tvb, offset, header_len,
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decode_boolean_bitfield(header, 0x2000, nbits,
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"SR", "No SR"), NULL);
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proto_tree_add_text(h_tree, tvb, offset, header_len,
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decode_boolean_bitfield(header, 0x1000, nbits,
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"RR", "No RR"), NULL);
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}
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return header_len;
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}
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void
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proto_register_v120(void)
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{
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static hf_register_info hf[] = {
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{ &hf_v120_address,
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{ "Link Address", "v120.address", FT_UINT16, BASE_HEX, NULL,
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0x0, "", HFILL }},
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{ &hf_v120_control,
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{ "Control Field", "v120.control", FT_UINT16, BASE_HEX, NULL, 0x0,
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"", HFILL }},
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{ &hf_v120_header,
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{ "Header Field", "v120.header", FT_STRING, BASE_NONE, NULL, 0x0,
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"", HFILL }},
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};
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static gint *ett[] = {
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&ett_v120,
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&ett_v120_address,
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&ett_v120_control,
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&ett_v120_header,
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};
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proto_v120 = proto_register_protocol("Async data over ISDN (V.120)",
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"V.120", "v120");
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proto_register_field_array (proto_v120, hf, array_length(hf));
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proto_register_subtree_array(ett, array_length(ett));
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}
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void
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proto_reg_handoff_v120(void)
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{
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dissector_add("wtap_encap", WTAP_ENCAP_V120, dissect_v120,
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proto_v120);
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}
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