epan/dissectors/packet-bicc_mst.c

   1 /* packet-bicc_mst.c
   2  * (Incomplete) Dissector for the 3GPP TS 29.205 BICC MST (Mobile Service Transport)
   3  *
   4  * This currently only dissects a single MST IE, which is required by the BSSMAP
   5  * dissector in order to decode the LCLS (Local Call Local Switch)
   6  * GCR (Global Call Reference)
   7  *
   8  * Copyright 2019 by Harald Welte <laforge@gnumonks.org>
   9  *
  10  * Wireshark - Network traffic analyzer
  11  * By Gerald Combs <gerald@wireshark.org>
  12  * Copyright 1998 Gerald Combs
  13  *
  14  * SPDX-License-Identifier: GPL-2.0-or-later
  15  */
  16
  17 #include "config.h"
  18
  19 #include <epan/packet.h>
  20 #include <epan/tap.h>
  21 #include <epan/expert.h>
  22
  23 #include "packet-bicc_mst.h"
  24
  25 void proto_register_bicc_mst(void);
  26
  27 static int proto_bicc_mst;
  28
  29 static int hf_lcls_gcr_network_id_len;
  30 static int hf_lcls_gcr_network_id;
  31 static int hf_lcls_gcr_node_id_len;
  32 static int hf_lcls_gcr_node_id;
  33 static int hf_lcls_gcr_call_ref_id_len;
  34 static int hf_lcls_gcr_call_ref_id;
  35
  36 static int ett_lcls_gcr;
  37
  38 unsigned
  39 dissect_bicc_mst_lcls_gcr(tvbuff_t *tvb, proto_tree *tree, uint32_t offset, unsigned len)
  40 {
  41         unsigned net_id_len, node_id_len, call_ref_id_len;
  42         uint32_t curr_offset = offset;
  43         proto_tree *subtree;
  44         proto_item *ti;
  45
  46         ti = proto_tree_add_protocol_format(tree, proto_bicc_mst, tvb, offset, len, "BICC MST GCR");
  47         subtree = proto_item_add_subtree(ti, ett_lcls_gcr);
  48
  49         proto_tree_add_item_ret_uint(subtree, hf_lcls_gcr_network_id_len, tvb, curr_offset++, 1, ENC_NA, &net_id_len);
  50         proto_tree_add_item(subtree, hf_lcls_gcr_network_id, tvb, curr_offset, net_id_len, ENC_NA);
  51         curr_offset += net_id_len;
  52
  53         proto_tree_add_item_ret_uint(subtree, hf_lcls_gcr_node_id_len, tvb, curr_offset++, 1, ENC_NA, &node_id_len);
  54         proto_tree_add_item(subtree, hf_lcls_gcr_node_id, tvb, curr_offset, node_id_len, ENC_NA);
  55         curr_offset += node_id_len;
  56
  57         proto_tree_add_item_ret_uint(subtree, hf_lcls_gcr_call_ref_id_len, tvb, curr_offset++, 1, ENC_NA, &call_ref_id_len);
  58         proto_tree_add_item(subtree, hf_lcls_gcr_call_ref_id, tvb, curr_offset, call_ref_id_len, ENC_NA);
  59         curr_offset += call_ref_id_len;
  60
  61         return curr_offset - offset;
  62 }
  63
  64 void
  65 proto_register_bicc_mst(void)
  66 {
  67         static hf_register_info hf[] = {
  68                 { &hf_lcls_gcr_network_id_len, { "Length of LCLS GCR Network ID",
  69                   "bicc_mst.lcls_gcr.network_id_len", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }},
  70                 { &hf_lcls_gcr_network_id, { "LCLS GCR Network ID",
  71                   "bicc_mst.lcls_gcr.network_id", FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL }},
  72                 { &hf_lcls_gcr_node_id_len, { "Length of LCLS GCR Node ID",
  73                   "bicc_mst.lcls_gcr.node_id_len", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }},
  74                 { &hf_lcls_gcr_node_id, { "LCLS GCR Network ID",
  75                   "bicc_mst.lcls_gcr.network_id", FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL }},
  76                 { &hf_lcls_gcr_call_ref_id_len, { "Length of LCLS GCR Call Ref ID",
  77                   "bicc_mst.lcls_gcr.call_ref_id_len", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }},
  78                 { &hf_lcls_gcr_call_ref_id, { "LCLS GCR Call Ref ID",
  79                   "bicc_mst.lcls_gcr.call_ref_id", FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL }},
  80         };
  81
  82         static int *ett[] = {
  83                 &ett_lcls_gcr,
  84         };
  85
  86         proto_bicc_mst = proto_register_protocol("3GPP BICC MST", "BICC-MST", "bicc_mst");
  87         proto_register_field_array(proto_bicc_mst, hf, array_length(hf));
  88         proto_register_subtree_array(ett, array_length(ett));
  89 }
  90
  91 /*
  92  * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
  93  *
  94  * Local variables:
  95  * c-basic-offset: 8
  96  * tab-width: 8
  97  * indent-tabs-mode: t
  98  * End:
  99  *
 100  * vi: set shiftwidth=8 tabstop=8 noexpandtab:
 101  * :indentSize=8:tabSize=8:noTabs=false:
 102  */