epan/dissectors/packet-dpnss-link.c

   1 /* packet-dpnss-link.c
   2  * Routines for DPNSS/DASS2 link layer dissection
   3  * Copyright 2009, Rolf Fiedler <rolf.fiedler[at]innoventif[dot]de>
   4  *
   5  * Wireshark - Network traffic analyzer
   6  * By Gerald Combs <gerald@wireshark.org>
   7  * Copyright 1998 Gerald Combs
   8  *
   9  * SPDX-License-Identifier: GPL-2.0-or-later
  10  */
  11 /* References:
  12  * BTNR188
  13  * ND1301:2001/03  http://www.nicc.org.uk/nicc-public/Public/interconnectstandards/dpnss/nd1301_2004_11.pdf
  14  */
  15
  16 #include "config.h"
  17
  18 #include <epan/packet.h>
  19 #include <wiretap/wtap.h>
  20
  21 void proto_register_dpnss_link(void);
  22 void proto_reg_handoff_dpnss_link(void);
  23
  24 static dissector_handle_t dpnss_handle; /* DPNSS UI frame dissector */
  25 #define LINK_HEADER_SIZE 3
  26
  27 static int proto_dpnss_link;
  28
  29 static int hf_dpnss_link_address_framegroup;
  30 static int hf_dpnss_link_address_crbit;
  31 static int hf_dpnss_link_address_extension;
  32 static int hf_dpnss_link_address2_reserved;
  33 static int hf_dpnss_link_address2_dlcId;
  34 static int hf_dpnss_link_address2_dlcIdNr;
  35 static int hf_dpnss_link_address2_extension;
  36 static int hf_dpnss_link_control_frameType;
  37
  38 static const value_string dpnss_link_framegroup_vals[] = {
  39         { 0x11, "Information Frame" },
  40         { 0x03, "Control Frame" },
  41         { 0, NULL }
  42 };
  43
  44 static const value_string dpnss_link_crbit_vals[] = {
  45         { 0x0, "Command/Response Bit Cleared" },
  46         { 0x1, "Command/Response Bit Set" },
  47         { 0, NULL }
  48 };
  49
  50 static const value_string dpnss_link_extend_vals[] = {
  51         { 0x0, "Extended to next octet" },
  52         { 0x1, "Final octet" },
  53         { 0, NULL }
  54 };
  55
  56 static const value_string dpnss_link_reserved_vals[] = {
  57         { 0x0, "Reserved" },
  58         { 0x1, "Reserved" },
  59         { 0, NULL }
  60 };
  61
  62 static const value_string dpnss_link_dlcId_vals[] = {
  63         { 0x0, "Real Channel" },
  64         { 0x1, "Virtual Channel" },
  65         { 0, NULL }
  66 };
  67
  68 #define FRAME_TYPE_UI_EVEN 0x03
  69 #define FRAME_TYPE_UI_ODD  0x13
  70 #define FRAME_TYPE_SABMR   0xef
  71 #define FRAME_TYPE_UA      0x63
  72
  73 static const value_string dpnss_link_frameType_vals[] = {
  74         { FRAME_TYPE_UI_EVEN, "UI (even)" },
  75         { FRAME_TYPE_UI_ODD,  "UI (odd)" },
  76         { FRAME_TYPE_SABMR,   "SABMR" },
  77         { FRAME_TYPE_UA,      "UA" },
  78         { 0, NULL }
  79 };
  80
  81 static int ett_dpnss_link;
  82
  83 static dissector_handle_t dpnss_link_handle;
  84
  85 /* Code to actually dissect the packets */
  86 static int
  87 dissect_dpnss_link(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
  88 {
  89         proto_item *item;
  90         proto_tree *dpnss_link_tree;
  91         uint8_t     octet;
  92         tvbuff_t   *protocol_data_tvb;
  93         uint16_t    protocol_data_length;
  94         bool        uton;
  95
  96         uton = pinfo->pseudo_header->l1event.uton;
  97         /* Make entries in src and dst column */
  98
  99         col_set_str(pinfo->cinfo, COL_DEF_SRC, uton?"TE":"NT");
 100         col_set_str(pinfo->cinfo, COL_DEF_DST, uton?"NT":"TE");
 101
 102         /* Make entries in Protocol column and Info column on summary display */
 103         col_set_str(pinfo->cinfo, COL_PROTOCOL, "DPNSS");
 104
 105         item = proto_tree_add_item(tree, proto_dpnss_link, tvb, 0, -1, ENC_NA);
 106         dpnss_link_tree = proto_item_add_subtree(item, ett_dpnss_link);
 107         proto_tree_add_item(dpnss_link_tree, hf_dpnss_link_address_framegroup,
 108                             tvb, 0, 1, ENC_BIG_ENDIAN);
 109         proto_tree_add_item(dpnss_link_tree, hf_dpnss_link_address_crbit,
 110                             tvb, 0, 1, ENC_BIG_ENDIAN);
 111         proto_tree_add_item(dpnss_link_tree, hf_dpnss_link_address_extension,
 112                             tvb, 0, 1, ENC_BIG_ENDIAN);
 113         proto_tree_add_item(dpnss_link_tree, hf_dpnss_link_address2_reserved,
 114                             tvb, 1, 1, ENC_BIG_ENDIAN);
 115         proto_tree_add_item(dpnss_link_tree, hf_dpnss_link_address2_dlcId,
 116                             tvb, 1, 1, ENC_BIG_ENDIAN);
 117         proto_tree_add_item(dpnss_link_tree, hf_dpnss_link_address2_dlcIdNr,
 118                             tvb, 1, 1, ENC_BIG_ENDIAN);
 119         proto_tree_add_item(dpnss_link_tree, hf_dpnss_link_address2_extension,
 120                             tvb, 1, 1, ENC_BIG_ENDIAN);
 121         /*
 122          * XXX - DPNSS's layer 2 protocol appears to be Yet Another
 123          * HDLC Derivative; should this use the xDLC control field
 124          * dissector code?
 125          */
 126         proto_tree_add_item(dpnss_link_tree, hf_dpnss_link_control_frameType,
 127                             tvb, 2, 1, ENC_BIG_ENDIAN);
 128         octet = tvb_get_uint8(tvb, 2);
 129         switch (octet){
 130         case FRAME_TYPE_UI_EVEN:
 131         case FRAME_TYPE_UI_ODD:
 132             protocol_data_length=tvb_reported_length(tvb)-LINK_HEADER_SIZE;
 133             protocol_data_tvb=tvb_new_subset_length(tvb, LINK_HEADER_SIZE,
 134                                              protocol_data_length);
 135             if (dpnss_handle && protocol_data_length>0) {
 136                 call_dissector(dpnss_handle, protocol_data_tvb, pinfo, tree);
 137             }
 138             break;
 139         default:
 140             break;
 141         }
 142         return tvb_captured_length(tvb);
 143 }
 144
 145
 146 /* Register the protocol with Wireshark */
 147 void
 148 proto_register_dpnss_link(void)
 149 {
 150         static hf_register_info hf[] = {
 151                 { &hf_dpnss_link_address_framegroup,
 152                   { "Frame Group", "dpnss_link.framegroup",
 153                     FT_UINT8, BASE_DEC, VALS(dpnss_link_framegroup_vals), 0xfc,
 154                     NULL, HFILL }
 155                 },
 156                 { &hf_dpnss_link_address_crbit,
 157                   { "C/R Bit", "dpnss_link.crbit",
 158                     FT_UINT8, BASE_DEC, VALS(dpnss_link_crbit_vals), 0x02,
 159                     NULL, HFILL }
 160                 },
 161                 { &hf_dpnss_link_address_extension,
 162                   { "Extension", "dpnss_link.extension",
 163                     FT_UINT8, BASE_DEC, VALS(dpnss_link_extend_vals), 0x01,
 164                     NULL, HFILL }
 165                 },
 166                 { &hf_dpnss_link_address2_reserved,
 167                   { "Reserved", "dpnss_link.reserved",
 168                     FT_UINT8, BASE_DEC, VALS(dpnss_link_reserved_vals), 0x80,
 169                     NULL, HFILL }
 170                 },
 171                 { &hf_dpnss_link_address2_dlcId,
 172                   { "DLC ID", "dpnss_link.dlcId",
 173                     FT_UINT8, BASE_DEC, VALS(dpnss_link_dlcId_vals), 0x40,
 174                     NULL, HFILL }
 175                 },
 176                 { &hf_dpnss_link_address2_dlcIdNr,
 177                   { "DLC ID Number", "dpnss_link.dlcIdNr",
 178                     FT_UINT8, BASE_DEC, NULL, 0x3e,
 179                     NULL, HFILL }
 180                 },
 181                 { &hf_dpnss_link_address2_extension,
 182                   { "Extension", "dpnss_link.extension2",
 183                     FT_UINT8, BASE_DEC, VALS(dpnss_link_extend_vals), 0x01,
 184                     NULL, HFILL }
 185                 },
 186                 { &hf_dpnss_link_control_frameType,
 187                   { "Frame Type", "dpnss_link.frameType",
 188                     FT_UINT8, BASE_DEC, VALS(dpnss_link_frameType_vals), 0x0,
 189                     NULL, HFILL }
 190                 }
 191         };
 192
 193         static int *ett[] = { &ett_dpnss_link };
 194
 195
 196         /* Register the protocol name and description */
 197         proto_dpnss_link = proto_register_protocol("Digital Private Signalling System No 1 Link Layer",
 198                                                    "DPNSS Link", "dpnss_link");
 199         dpnss_link_handle = register_dissector("dpnss_link", dissect_dpnss_link, proto_dpnss_link);
 200
 201         /* Required function calls to register the header fields and subtrees used */
 202         proto_register_field_array(proto_dpnss_link, hf, array_length(hf));
 203         proto_register_subtree_array(ett, array_length(ett));
 204 }
 205
 206 void
 207 proto_reg_handoff_dpnss_link(void)
 208 {
 209         dissector_add_uint("wtap_encap", WTAP_ENCAP_DPNSS, dpnss_link_handle);
 210
 211         dpnss_handle = find_dissector_add_dependency("dpnss", proto_dpnss_link);
 212 }
 213
 214 /*
 215  * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
 216  *
 217  * Local variables:
 218  * c-basic-offset: 8
 219  * tab-width: 8
 220  * indent-tabs-mode: t
 221  * End:
 222  *
 223  * vi: set shiftwidth=8 tabstop=8 noexpandtab:
 224  * :indentSize=8:tabSize=8:noTabs=false:
 225  */