epan/dissectors/packet-lapbether.c

   1 /* packet-lapbether.c
   2  * Routines for lapbether frame disassembly
   3  * Richard Sharpe <rsharpe@ns.aus.com> based on the lapb module by
   4  * Olivier Abad <oabad@noos.fr>
   5  *
   6  * $Id$
   7  *
   8  * Wireshark - Network traffic analyzer
   9  * By Gerald Combs <gerald@wireshark.org>
  10  * Copyright 1998
  11  *
  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.
  16  *
  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.
  21  *
  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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  25  */
  26
  27 #include "config.h"
  28
  29 #include <glib.h>
  30 #include <epan/packet.h>
  31 #include <epan/etypes.h>
  32
  33 static int proto_lapbether = -1;
  34
  35 static int hf_lapbether_length = -1;
  36
  37 static gint ett_lapbether = -1;
  38
  39 static dissector_handle_t lapb_handle;
  40
  41 static void
  42 dissect_lapbether(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
  43 {
  44     proto_tree          *lapbether_tree, *ti;
  45     int                 len;
  46     tvbuff_t            *next_tvb;
  47
  48     col_set_str(pinfo->cinfo, COL_PROTOCOL, "LAPBETHER");
  49     col_clear(pinfo->cinfo, COL_INFO);
  50
  51     len = tvb_get_guint8(tvb, 0) + tvb_get_guint8(tvb, 1) * 256;
  52
  53     if (tree) {
  54
  55       ti = proto_tree_add_protocol_format(tree, proto_lapbether, tvb, 0, 2,
  56                                           "LAPBETHER");
  57
  58       lapbether_tree = proto_item_add_subtree(ti, ett_lapbether);
  59       proto_tree_add_uint_format(lapbether_tree, hf_lapbether_length, tvb, 0, 2,
  60                                  len, "Length: %u", len);
  61
  62     }
  63
  64     next_tvb = tvb_new_subset(tvb, 2, len, len);
  65     call_dissector(lapb_handle, next_tvb, pinfo, tree);
  66
  67 }
  68
  69 void
  70 proto_register_lapbether(void)
  71 {
  72     static hf_register_info hf[] = {
  73       { &hf_lapbether_length,
  74         { "Length Field", "lapbether.length", FT_UINT16, BASE_DEC, NULL, 0x0,
  75           "LAPBEther Length Field", HFILL }},
  76
  77     };
  78     static gint *ett[] = {
  79         &ett_lapbether,
  80     };
  81
  82     proto_lapbether = proto_register_protocol ("Link Access Procedure Balanced Ethernet (LAPBETHER)",
  83         "LAPBETHER", "lapbether");
  84     proto_register_field_array (proto_lapbether, hf, array_length(hf));
  85     proto_register_subtree_array(ett, array_length(ett));
  86 }
  87
  88 /* The registration hand-off routine */
  89 void
  90 proto_reg_handoff_lapbether(void)
  91 {
  92   dissector_handle_t lapbether_handle;
  93
  94   /*
  95    * Get a handle for the LAPB dissector.
  96    */
  97   lapb_handle = find_dissector("lapb");
  98
  99   lapbether_handle = create_dissector_handle(dissect_lapbether,
 100                                              proto_lapbether);
 101   dissector_add_uint("ethertype", ETHERTYPE_DEC, lapbether_handle);
 102
 103 }