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  * Wireshark - Network traffic analyzer
   7  * By Gerald Combs <gerald@wireshark.org>
   8  * Copyright 1998
   9  *
  10  * SPDX-License-Identifier: GPL-2.0-or-later
  11  */
  12
  13 #include "config.h"
  14
  15 #include <epan/packet.h>
  16 #include <epan/etypes.h>
  17
  18 void proto_register_lapbether(void);
  19 void proto_reg_handoff_lapbether(void);
  20
  21 static int proto_lapbether = -1;
  22
  23 static int hf_lapbether_length = -1;
  24
  25 static gint ett_lapbether = -1;
  26
  27 static dissector_handle_t lapb_handle;
  28
  29 static int
  30 dissect_lapbether(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
  31 {
  32     proto_tree *lapbether_tree, *ti;
  33     int         len;
  34     tvbuff_t   *next_tvb;
  35
  36     col_set_str(pinfo->cinfo, COL_PROTOCOL, "LAPBETHER");
  37     col_clear(pinfo->cinfo, COL_INFO);
  38
  39     len = tvb_get_guint8(tvb, 0) + tvb_get_guint8(tvb, 1) * 256;
  40
  41     if (tree) {
  42
  43       ti = proto_tree_add_protocol_format(tree, proto_lapbether, tvb, 0, 2,
  44                                           "LAPBETHER");
  45
  46       lapbether_tree = proto_item_add_subtree(ti, ett_lapbether);
  47       proto_tree_add_uint_format(lapbether_tree, hf_lapbether_length, tvb, 0, 2,
  48                                  len, "Length: %u", len);
  49
  50     }
  51
  52     next_tvb = tvb_new_subset_length(tvb, 2, len);
  53     call_dissector(lapb_handle, next_tvb, pinfo, tree);
  54
  55     return tvb_captured_length(tvb);
  56 }
  57
  58 void
  59 proto_register_lapbether(void)
  60 {
  61     static hf_register_info hf[] = {
  62       { &hf_lapbether_length,
  63         { "Length Field", "lapbether.length", FT_UINT16, BASE_DEC, NULL, 0x0,
  64           "LAPBEther Length Field", HFILL }},
  65
  66     };
  67     static gint *ett[] = {
  68         &ett_lapbether,
  69     };
  70
  71     proto_lapbether = proto_register_protocol ("Link Access Procedure Balanced Ethernet (LAPBETHER)",
  72         "LAPBETHER", "lapbether");
  73     proto_register_field_array (proto_lapbether, hf, array_length(hf));
  74     proto_register_subtree_array(ett, array_length(ett));
  75 }
  76
  77 /* The registration hand-off routine */
  78 void
  79 proto_reg_handoff_lapbether(void)
  80 {
  81   dissector_handle_t lapbether_handle;
  82
  83   /*
  84    * Get a handle for the LAPB dissector.
  85    */
  86   lapb_handle = find_dissector_add_dependency("lapb", proto_lapbether);
  87
  88   lapbether_handle = create_dissector_handle(dissect_lapbether,
  89                                              proto_lapbether);
  90   dissector_add_uint("ethertype", ETHERTYPE_DEC, lapbether_handle);
  91
  92 }
  93
  94 /*
  95  * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
  96  *
  97  * Local Variables:
  98  * c-basic-offset: 2
  99  * tab-width: 8
 100  * indent-tabs-mode: nil
 101  * End:
 102  *
 103  * ex: set shiftwidth=2 tabstop=8 expandtab:
 104  * :indentSize=2:tabSize=8:noTabs=true:
 105  */