epan/dissectors/packet-mdp.c

   1 /* packet-mdp.c
   2  * Routines for the disassembly of the "Meraki Discovery Protocol (MDP)"
   3  *
   4  * Wireshark - Network traffic analyzer
   5  * By Gerald Combs <gerald@wireshark.org>
   6  * Copyright 1998 Gerald Combs
   7  *
   8  * SPDX-License-Identifier: GPL-2.0-or-later
   9  */
  10
  11 #include "config.h"
  12 #include <epan/packet.h>
  13
  14 #define MDP_TLV_TYPE            0
  15 #define MDP_TLV_LENGTH          1
  16 #define MDP_TLV_DEVICE_INFO     2
  17 #define MDP_TLV_NETWORK_INFO    3
  18 #define MDP_TLV_LONGITUDE       4
  19 #define MDP_TLV_LATITUDE        5
  20 #define MDP_TLV_TYPE_SIX        6
  21 #define MDP_TLV_TYPE_SEVEN      7
  22 #define MDP_TLV_END             255
  23
  24 void proto_register_mdp(void);
  25 void proto_reg_handoff_mdp(void);
  26
  27 static int proto_mdp;
  28 static int hf_mdp_preamble_data;
  29 static int hf_mdp_device_info;
  30 static int hf_mdp_network_info;
  31 static int hf_mdp_type;
  32 static int hf_mdp_length;
  33 static int hf_mdp_longitude;
  34 static int hf_mdp_latitude;
  35 static int hf_mdp_type_six;
  36 static int hf_mdp_type_seven;
  37 static int hf_mdp_data;
  38
  39 static int ett_mdp;
  40 static int ett_mdp_tlv;
  41
  42 static dissector_handle_t mdp_handle;
  43
  44 /* Format Identifier */
  45 static const value_string type_vals[] = {
  46     { MDP_TLV_DEVICE_INFO, "Device Info" },
  47     { MDP_TLV_NETWORK_INFO, "Network Info" },
  48     { MDP_TLV_LONGITUDE, "Longitude" },
  49     { MDP_TLV_LATITUDE, "Latitude" },
  50     { MDP_TLV_TYPE_SIX, "Type 6 UID" },
  51     { MDP_TLV_TYPE_SEVEN, "Type 7 UID" },
  52     { MDP_TLV_END, "End" },
  53     { 0, NULL }
  54 };
  55
  56 static int
  57 dissect_mdp(tvbuff_t *mdp_tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
  58 {
  59     proto_tree  *mdp_tree, *tlv_tree;
  60     proto_item  *mdp_item, *tlv_item;
  61     uint32_t    mdp_type, mdp_length;
  62     int offset = 0;
  63
  64     col_set_str(pinfo->cinfo, COL_PROTOCOL, "MDP");
  65     col_set_str(pinfo->cinfo, COL_INFO, "MDP");
  66
  67     mdp_item = proto_tree_add_item(tree, proto_mdp, mdp_tvb, 0, -1, ENC_NA);
  68     mdp_tree = proto_item_add_subtree(mdp_item, ett_mdp);
  69
  70     proto_tree_add_item(mdp_tree, hf_mdp_preamble_data, mdp_tvb, 0, 28, ENC_NA);
  71     offset += 28;
  72
  73     while(tvb_reported_length_remaining(mdp_tvb, offset) != 0){
  74         tlv_tree = proto_tree_add_subtree(mdp_tree, mdp_tvb, offset + MDP_TLV_TYPE, -1, ett_mdp_tlv, &tlv_item, "");
  75         proto_tree_add_item_ret_uint(tlv_tree, hf_mdp_type, mdp_tvb, offset + MDP_TLV_TYPE, 1, ENC_BIG_ENDIAN, &mdp_type);
  76         proto_item_set_text(tlv_tree, "%s", val_to_str_const(mdp_type, type_vals, "Unknown type"));
  77         proto_tree_add_item_ret_uint(tlv_tree, hf_mdp_length, mdp_tvb, offset + MDP_TLV_LENGTH, 1, ENC_BIG_ENDIAN, &mdp_length);
  78
  79         offset += 2;
  80
  81         switch(mdp_type){
  82           case MDP_TLV_DEVICE_INFO:
  83             proto_tree_add_item(tlv_tree, hf_mdp_device_info, mdp_tvb, offset, mdp_length, ENC_UTF_8 | ENC_NA);
  84             break;
  85           case MDP_TLV_NETWORK_INFO:
  86             proto_tree_add_item(tlv_tree, hf_mdp_network_info, mdp_tvb, offset, mdp_length, ENC_UTF_8 | ENC_NA);
  87              break;
  88           case MDP_TLV_LONGITUDE:
  89             proto_tree_add_item(tlv_tree, hf_mdp_longitude, mdp_tvb, offset, mdp_length, ENC_UTF_8 | ENC_NA);
  90             break;
  91           case MDP_TLV_LATITUDE:
  92             proto_tree_add_item(tlv_tree, hf_mdp_latitude, mdp_tvb, offset, mdp_length, ENC_UTF_8 | ENC_NA);
  93             break;
  94           case MDP_TLV_TYPE_SIX:
  95             proto_tree_add_item(tlv_tree, hf_mdp_type_six, mdp_tvb, offset, mdp_length, ENC_UTF_8 | ENC_NA);
  96             break;
  97           case MDP_TLV_TYPE_SEVEN:
  98             proto_tree_add_item(tlv_tree, hf_mdp_type_seven, mdp_tvb, offset, mdp_length, ENC_UTF_8 | ENC_NA);
  99             break;
 100           case MDP_TLV_END:
 101             break;
 102           default:
 103             proto_tree_add_item(mdp_tree, hf_mdp_data, mdp_tvb, offset, mdp_length, ENC_NA);
 104             break;
 105         }
 106         proto_item_set_len(tlv_item, mdp_length + 2);
 107         offset += mdp_length;
 108     }
 109     return tvb_captured_length(mdp_tvb);
 110 }
 111
 112 void
 113 proto_register_mdp(void)
 114 {
 115
 116     static hf_register_info hf[] = {
 117         { &hf_mdp_preamble_data, {"Preamble Data","mdp.preamble_data", FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL }},
 118         { &hf_mdp_device_info, {"Device Info", "mdp.device_info", FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL }},
 119         { &hf_mdp_network_info, {"Network Info", "mdp.network_info", FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL }},
 120         { &hf_mdp_longitude, {"Longitude", "mdp.longitude", FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL }},
 121         { &hf_mdp_latitude, {"Latitude", "mdp.latitude", FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL }},
 122         { &hf_mdp_type, {"Type", "mdp.type", FT_UINT8, BASE_DEC, VALS(type_vals), 0x0, NULL, HFILL }},
 123         { &hf_mdp_type_six, {"Type 6 UID", "mdp.type_six", FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL }},
 124         { &hf_mdp_type_seven, {"Type 7 UID", "mdp.type_seven", FT_STRING, BASE_NONE, NULL, 0x0, NULL, HFILL }},
 125         { &hf_mdp_length, {"Length", "mdp.length", FT_UINT8, BASE_DEC, NULL, 0x0, NULL, HFILL }},
 126         { &hf_mdp_data, {"Unknown Data", "mdp.data", FT_BYTES, BASE_NONE, NULL, 0x0, NULL, HFILL }}
 127     };
 128
 129     static int *ett[] = {
 130         &ett_mdp,
 131         &ett_mdp_tlv
 132     };
 133
 134     proto_mdp = proto_register_protocol("Meraki Discovery Protocol", "MDP", "mdp");
 135     proto_register_field_array(proto_mdp, hf, array_length(hf));
 136     proto_register_subtree_array(ett, array_length(ett));
 137
 138     mdp_handle = register_dissector("mdp", dissect_mdp, proto_mdp);
 139 }
 140
 141 void
 142 proto_reg_handoff_mdp(void)
 143 {
 144     dissector_add_uint("ethertype", 0x0712, mdp_handle);
 145     dissector_add_uint("ethertype", 0x0713, mdp_handle);
 146 }
 147
 148 /*
 149  * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
 150  *
 151  * Local variables:
 152  * c-basic-offset: 4
 153  * tab-width: 8
 154  * indent-tabs-mode: nil
 155  * End:
 156  *
 157  * vi: set shiftwidth=4 tabstop=8 expandtab:
 158  * :indentSize=4:tabSize=8:noTabs=true:
 159  */