/* packet-v120.c * Routines for v120 frame disassembly * Bert Driehuis * * $Id: packet-v120.c,v 1.30 2002/10/31 07:43:10 guy Exp $ * * Ethereal - Network traffic analyzer * By Gerald Combs * 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 #include #include #include #include #include "xdlc.h" 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; static dissector_handle_t data_handle; static int dissect_v120_header(tvbuff_t *tvb, int offset, proto_tree *tree); static void dissect_v120(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) { proto_tree *v120_tree, *tc, *address_tree; proto_item *ti; int is_response; int addr; char info[80]; int v120len; guint8 byte0, byte1; guint16 control; tvbuff_t *next_tvb; if (check_col(pinfo->cinfo, COL_PROTOCOL)) col_set_str(pinfo->cinfo, COL_PROTOCOL, "V.120"); if (check_col(pinfo->cinfo, COL_INFO)) col_clear(pinfo->cinfo, COL_INFO); byte0 = tvb_get_guint8(tvb, 0); if(check_col(pinfo->cinfo, COL_RES_DL_SRC)) col_add_fstr(pinfo->cinfo, COL_RES_DL_SRC, "0x%02X", byte0); byte1 = tvb_get_guint8(tvb, 1); if ((byte0 & 0x01) != 0x00 && (byte1 && 0x01) != 0x01) { if (check_col(pinfo->cinfo, COL_INFO)) col_set_str(pinfo->cinfo, COL_INFO, "Invalid V.120 frame"); if (tree) ti = proto_tree_add_protocol_format(tree, proto_v120, tvb, 0, -1, "Invalid V.120 frame"); return; } if (pinfo->p2p_dir == P2P_DIR_SENT) { is_response = (byte0 & 0x02) ? FALSE: TRUE; if(check_col(pinfo->cinfo, COL_RES_DL_DST)) col_set_str(pinfo->cinfo, COL_RES_DL_DST, "DCE"); if(check_col(pinfo->cinfo, COL_RES_DL_SRC)) col_set_str(pinfo->cinfo, COL_RES_DL_SRC, "DTE"); } else { /* XXX - what if the direction is unknown? */ is_response = (byte0 & 0x02) ? TRUE : FALSE; if(check_col(pinfo->cinfo, COL_RES_DL_DST)) col_set_str(pinfo->cinfo, COL_RES_DL_DST, "DTE"); if(check_col(pinfo->cinfo, COL_RES_DL_SRC)) col_set_str(pinfo->cinfo, COL_RES_DL_SRC, "DCE"); } if (tree) { ti = proto_tree_add_protocol_format(tree, proto_v120, tvb, 0, -1, "V.120"); v120_tree = proto_item_add_subtree(ti, ett_v120); addr = byte1 << 8 | byte0; sprintf(info, "LLI: %d C/R: %s", ((byte0 & 0xfc) << 5) | ((byte1 & 0xfe) >> 1), byte0 & 0x02 ? "R" : "C"); tc = proto_tree_add_text(v120_tree, tvb, 0, 2, "Address field: %s", info); address_tree = proto_item_add_subtree(tc, ett_v120_address); proto_tree_add_text(address_tree, tvb, 0, 2, decode_boolean_bitfield(addr, 0x0002, 2*8, "Response", "Command"), NULL); sprintf(info, "LLI: %d", ((byte0 & 0xfc) << 5) | ((byte1 & 0xfe) >> 1)); proto_tree_add_text(address_tree, tvb, 0, 2, decode_numeric_bitfield(addr, 0xfefc, 2*8, info)); proto_tree_add_text(address_tree, tvb, 0, 2, decode_boolean_bitfield(addr, 0x0001, 2*8, "EA0 = 1 (Error)", "EA0 = 0"), NULL); proto_tree_add_text(address_tree, tvb, 0, 2, decode_boolean_bitfield(addr, 0x0100, 2*8, "EA1 = 1", "EA1 = 0 (Error)"), NULL); } else { v120_tree = NULL; ti = NULL; } control = dissect_xdlc_control(tvb, 2, pinfo, v120_tree, hf_v120_control, ett_v120_control, is_response, TRUE); if (tree) { 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(tvb, v120len, -1, -1); call_dissector(data_handle,next_tvb, pinfo, v120_tree); } } static int dissect_v120_header(tvbuff_t *tvb, int offset, proto_tree *tree) { char info[80]; int header_len, nbits; int header; proto_tree *h_tree, *tc; guint8 byte0; byte0 = tvb_get_guint8(tvb, offset); if (byte0 & 0x80) { header_len = 1; header = byte0; } else { header_len = 2; header = byte0 | tvb_get_guint8(tvb, offset + 1) << 8; } nbits = header_len * 8; sprintf(info, "Header: B: %d F: %d", byte0 & 0x02 ? 1:0, byte0 & 0x01 ? 1:0); tc = proto_tree_add_text(tree, tvb, offset, header_len, "Header octet: %s (0x%02X)", info, byte0); h_tree = proto_item_add_subtree(tc, ett_v120_header); proto_tree_add_text(h_tree, tvb, offset, header_len, decode_boolean_bitfield(header, 0x80, nbits, "No extension octet", "Extension octet follows"), NULL); proto_tree_add_text(h_tree, tvb, 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, tvb, offset, header_len, decode_numeric_bitfield(header, 0x0c, nbits, info)); proto_tree_add_text(h_tree, tvb, offset, header_len, decode_boolean_bitfield(header, 0x02, nbits, "Segmentation bit B", "No segmentation bit B"), NULL); proto_tree_add_text(h_tree, tvb, 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, tvb, offset, header_len, decode_boolean_bitfield(header, 0x8000, nbits, "E", "E bit not set (Error)"), NULL); proto_tree_add_text(h_tree, tvb, offset, header_len, decode_boolean_bitfield(header, 0x4000, nbits, "DR", "No DR"), NULL); proto_tree_add_text(h_tree, tvb, offset, header_len, decode_boolean_bitfield(header, 0x2000, nbits, "SR", "No SR"), NULL); proto_tree_add_text(h_tree, tvb, offset, header_len, decode_boolean_bitfield(header, 0x1000, nbits, "RR", "No RR"), NULL); } 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, "", HFILL }}, { &hf_v120_control, { "Control Field", "v120.control", FT_UINT16, BASE_HEX, NULL, 0x0, "", HFILL }}, { &hf_v120_header, { "Header Field", "v120.header", FT_STRING, BASE_NONE, NULL, 0x0, "", HFILL }}, }; 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)", "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); } void proto_reg_handoff_v120(void) { data_handle = find_dissector("data"); }