119 lines
3.3 KiB
C
119 lines
3.3 KiB
C
/* packet-lapb.c
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* Routines for lapb frame disassembly
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* Olivier Abad <abad@daba.dhis.org>
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*
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* $Id: packet-lapb.c,v 1.6 1999/10/12 06:20:11 gram 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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int proto_lapb = -1;
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int hf_lapb_address = -1;
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int hf_lapb_control = -1;
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void
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dissect_lapb(const u_char *pd, frame_data *fd, proto_tree *tree)
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{
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proto_tree *lapb_tree, *ti;
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int is_response;
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if (check_col(fd, COL_PROTOCOL))
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col_add_str(fd, COL_PROTOCOL, "LAPB");
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if(check_col(fd, COL_RES_DL_SRC))
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col_add_fstr(fd, COL_RES_DL_SRC, "0x%02X", pd[0]);
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if (pd[0] != 0x01 && pd[0] != 0x03) /* invalid LAPB frame */
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{
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if (check_col(fd, COL_INFO))
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col_add_str(fd, COL_INFO, "Invalid LAPB frame");
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if (tree)
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ti = proto_tree_add_item_format(tree, proto_lapb, 0, fd->cap_len,
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NULL, "Invalid LAPB frame");
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return;
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}
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if (fd->pseudo_header.x25.flags & FROM_DCE) {
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if(check_col(fd, COL_RES_DL_DST))
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col_add_str(fd, COL_RES_DL_DST, "DTE");
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if(check_col(fd, COL_RES_DL_SRC))
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col_add_str(fd, COL_RES_DL_SRC, "DCE");
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}
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else {
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if(check_col(fd, COL_RES_DL_DST))
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col_add_str(fd, COL_RES_DL_DST, "DCE");
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if(check_col(fd, COL_RES_DL_SRC))
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col_add_str(fd, COL_RES_DL_SRC, "DTE");
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}
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if (((fd->pseudo_header.x25.flags & FROM_DCE) && pd[0] == 0x01) ||
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(!(fd->pseudo_header.x25.flags & FROM_DCE) && pd[0] == 0x03))
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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_item_format(tree, proto_lapb, 0, 2, NULL,
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"LAPB");
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lapb_tree = proto_item_add_subtree(ti, ETT_LAPB);
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proto_tree_add_item_format(lapb_tree, hf_lapb_address, 0, 1, pd[0],
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"Address: 0x%02X", pd[0]);
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}
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else
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lapb_tree = NULL;
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dissect_xdlc_control(pd, 1, fd, lapb_tree, hf_lapb_control,
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is_response, FALSE);
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/* not end of frame ==> X.25 */
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if (fd->cap_len > 2) dissect_x25(pd, 2, fd, tree);
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}
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void
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proto_register_lapb(void)
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{
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static hf_register_info hf[] = {
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{ &hf_lapb_address,
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{ "Address Field", "lapb.address", FT_UINT8, BASE_DEC, NULL, 0x0,
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"" }},
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{ &hf_lapb_control,
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{ "Control Field", "lapb.control", FT_STRING, BASE_NONE, NULL, 0x0,
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"" }},
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};
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proto_lapb = proto_register_protocol ("LAPB", "lapb");
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proto_register_field_array (proto_lapb, hf, array_length(hf));
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}
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