epan/dissectors/packet-mqtt-sn.c

   1 /* packet-mqtt-sn.c
   2  *
   3  * Routines for MQTT-SN v1.2 <http://mqtt.org>
   4  *
   5  * Copyright (c) 2015, Jan-Hendrik Bolte <jabolte@uni-osnabrueck.de>
   6  * Copyright (c) 2015, University of Osnabrueck
   7  *
   8  * Wireshark - Network traffic analyzer
   9  * By Gerald Combs <gerald@wireshark.org>
  10  * Copyright 1998 Gerald Combs
  11  *
  12  * SPDX-License-Identifier: GPL-2.0-or-later
  13  */
  14
  15 #include "config.h"
  16 #include <epan/packet.h>
  17 #include <epan/tfs.h>
  18 #include <wsutil/array.h>
  19
  20 /* MQTT-SN message types. */
  21 #define MQTTSN_ADVERTISE              0x00
  22 #define MQTTSN_SEARCHGW               0x01
  23 #define MQTTSN_GWINFO                 0x02
  24 #define MQTTSN_RESERVED_03            0x03
  25 #define MQTTSN_CONNECT                0x04
  26 #define MQTTSN_CONNACK                0x05
  27 #define MQTTSN_WILLTOPICREQ           0x06
  28 #define MQTTSN_WILLTOPIC              0x07
  29 #define MQTTSN_WILLMSGREQ             0x08
  30 #define MQTTSN_WILLMSG                0x09
  31 #define MQTTSN_REGISTER               0x0A
  32 #define MQTTSN_REGACK                 0x0B
  33 #define MQTTSN_PUBLISH                0x0C
  34 #define MQTTSN_PUBACK                 0x0D
  35 #define MQTTSN_PUBCOMP                0x0E
  36 #define MQTTSN_PUBREC                 0x0F
  37 #define MQTTSN_PUBREL                 0x10
  38 #define MQTTSN_RESERVED_11            0x11
  39 #define MQTTSN_SUBSCRIBE              0x12
  40 #define MQTTSN_SUBACK                 0x13
  41 #define MQTTSN_UNSUBSCRIBE            0x14
  42 #define MQTTSN_UNSUBACK               0x15
  43 #define MQTTSN_PINGREQ                0x16
  44 #define MQTTSN_PINGRESP               0x17
  45 #define MQTTSN_DISCONNECT             0x18
  46 #define MQTTSN_RESERVED_19            0x19
  47 #define MQTTSN_WILLTOPICUPD           0x1A
  48 #define MQTTSN_WILLTOPICRESP          0x1B
  49 #define MQTTSN_WILLMSGUPD             0x1C
  50 #define MQTTSN_WILLMSGRESP            0x1D
  51 #define MQTTSN_ENCAPSULATED_MSG       0xFE
  52
  53 /* Masks to extract flag values. */
  54 #define MQTTSN_MASK_DUP_FLAG          0x80
  55 #define MQTTSN_MASK_QOS               0x60
  56 #define MQTTSN_MASK_RETAIN            0x10
  57 #define MQTTSN_MASK_WILL              0x08
  58 #define MQTTSN_MASK_CLEAN             0x04
  59 #define MQTTSN_MASK_TOPIC_ID_TYPE     0x03
  60
  61 /* Mask to extract radius from control. */
  62 #define MQTTSN_MASK_CONTROL           0x03
  63
  64 /* MQTT-SN QoS levels. */
  65 #define MQTTSN_QOS_ATMOST_ONCE      0x00
  66 #define MQTTSN_QOS_ATLEAST_ONCE     0x01
  67 #define MQTTSN_QOS_EXACTLY_ONCE     0x02
  68 #define MQTTSN_QOS_NO_CONNECTION    0x03
  69
  70 /* MQTT-SN topic types. */
  71 #define MQTTSN_TOPIC_NORMAL_ID      0x00
  72 #define MQTTSN_TOPIC_PREDEF_ID      0x01
  73 #define MQTTSN_TOPIC_SHORT_NAME     0x02
  74 #define MQTTSN_TOPIC_RESERVED       0x03
  75
  76 /* MQTT-SN connection return types. */
  77 #define MQTTSN_CON_ACCEPTED                   0x00
  78 #define MQTTSN_CON_REFUSED_CONGESTION         0x01
  79 #define MQTTSN_CON_REFUSED_INVALID_TOPIC_ID   0x02
  80 #define MQTTSN_CON_REFUSED_NOT_SUPPORTED      0x03
  81
  82 void proto_register_mqttsn(void);
  83 void proto_reg_handoff_mqttsn(void);
  84
  85 /* MQTT-SN message type values. */
  86 static const value_string mqttsn_msgtype_vals[] = {
  87     { MQTTSN_ADVERTISE,           "Advertise Gateway" },
  88     { MQTTSN_SEARCHGW,            "Search Gateway" },
  89     { MQTTSN_GWINFO,              "Gateway Info" },
  90     { MQTTSN_RESERVED_03,         "Reserved_03" },
  91     { MQTTSN_CONNECT,             "Connect Command" },
  92     { MQTTSN_CONNACK,             "Connect Ack" },
  93     { MQTTSN_WILLTOPICREQ,        "Will Topic Request" },
  94     { MQTTSN_WILLTOPIC,           "Will Topic" },
  95     { MQTTSN_WILLMSGREQ,          "Will Message Request" },
  96     { MQTTSN_WILLMSG,             "Will Message" },
  97     { MQTTSN_REGISTER,            "Register" },
  98     { MQTTSN_REGACK,              "Register Ack" },
  99     { MQTTSN_PUBLISH,             "Publish Message" },
 100     { MQTTSN_PUBACK,              "Publish Ack" },
 101     { MQTTSN_PUBCOMP,             "Publish Complete" },
 102     { MQTTSN_PUBREC,              "Publish Received" },
 103     { MQTTSN_PUBREL,              "Publish Release" },
 104     { MQTTSN_RESERVED_11,         "Reserved_11" },
 105     { MQTTSN_SUBSCRIBE,           "Subscribe Request" },
 106     { MQTTSN_SUBACK,              "Subscribe Ack" },
 107     { MQTTSN_UNSUBSCRIBE,         "Unsubscribe Request" },
 108     { MQTTSN_UNSUBACK,            "Unsubscribe Ack" },
 109     { MQTTSN_PINGREQ,             "Ping Request" },
 110     { MQTTSN_PINGRESP,            "Ping Response" },
 111     { MQTTSN_DISCONNECT,          "Disconnect Req" },
 112     { MQTTSN_RESERVED_19,         "Reserved_19" },
 113     { MQTTSN_WILLTOPICUPD,        "Will Topic Update" },
 114     { MQTTSN_WILLTOPICRESP,       "Will Topic Response" },
 115     { MQTTSN_WILLMSGUPD,          "Will Message Update" },
 116     { MQTTSN_WILLMSGRESP,         "Will Message Response" },
 117     { MQTTSN_ENCAPSULATED_MSG,    "Encapsulated Message" },
 118     { 0,                          NULL }
 119 };
 120 static value_string_ext mqttsn_msgtype_vals_ext = VALUE_STRING_EXT_INIT(mqttsn_msgtype_vals);
 121
 122 /* MQTT-SN QoS level values. */
 123 static const value_string mqttsn_qos_vals[] = {
 124     { MQTTSN_QOS_ATMOST_ONCE,         "Fire and Forget" },
 125     { MQTTSN_QOS_ATLEAST_ONCE,        "Acknowledged deliver" },
 126     { MQTTSN_QOS_EXACTLY_ONCE,        "Assured Delivery" },
 127     { MQTTSN_QOS_NO_CONNECTION,       "No Connection required" },
 128     { 0,                              NULL }
 129 };
 130
 131 /* MQTT-SN topic type values. */
 132 static const value_string mqttsn_typeid_vals[] = {
 133     { MQTTSN_TOPIC_NORMAL_ID,         "Normal ID" },
 134     { MQTTSN_TOPIC_PREDEF_ID,         "Pre-defined ID" },
 135     { MQTTSN_TOPIC_SHORT_NAME,        "Short Topic Name" },
 136     { MQTTSN_TOPIC_RESERVED,          "Reserved" },
 137     { 0,                              NULL }
 138 };
 139
 140 /* MQTT-SN connection return type values. */
 141 static const value_string mqttsn_return_vals[] = {
 142     { MQTTSN_CON_ACCEPTED,                      "Accepted" },
 143     { MQTTSN_CON_REFUSED_CONGESTION,            "Rejected: Congestion" },
 144     { MQTTSN_CON_REFUSED_INVALID_TOPIC_ID,      "Rejected: invalid topic ID" },
 145     { MQTTSN_CON_REFUSED_NOT_SUPPORTED,         "Rejected: not supported" },
 146     { 0,                                        NULL }
 147 };
 148
 149 /* MQTT-SN Handle */
 150 static dissector_handle_t mqttsn_handle;
 151
 152 /* Initialize the protocol and registered fields. */
 153 static int proto_mqttsn;
 154
 155 static int hf_mqttsn_msg;
 156 static int hf_mqttsn_msg_len;
 157 static int hf_mqttsn_msg_type;
 158 static int hf_mqttsn_dup;
 159 static int hf_mqttsn_qos;
 160 static int hf_mqttsn_retain;
 161 static int hf_mqttsn_will;
 162 static int hf_mqttsn_clean_session;
 163 static int hf_mqttsn_topic_id_type;
 164 static int hf_mqttsn_return_code;
 165 static int hf_mqttsn_gw_id;
 166 static int hf_mqttsn_gw_addr;
 167 static int hf_mqttsn_adv_interv;
 168 static int hf_mqttsn_radius;
 169 static int hf_mqttsn_protocol_id;
 170 static int hf_mqttsn_topic_id;
 171 static int hf_mqttsn_msg_id;
 172 static int hf_mqttsn_topic;
 173 static int hf_mqttsn_topic_name_or_id;
 174 static int hf_mqttsn_sleep_timer;
 175 static int hf_mqttsn_will_topic;
 176 static int hf_mqttsn_will_msg;
 177 static int hf_mqttsn_pub_msg;
 178 static int hf_mqttsn_client_id;
 179 static int hf_mqttsn_keep_alive;
 180 static int hf_mqttsn_control_info;
 181 static int hf_mqttsn_wireless_node_id;
 182
 183 /* Initialize subtree pointers. */
 184 static int ett_mqttsn_hdr;
 185 static int ett_mqttsn_msg;
 186 static int ett_mqttsn_flags;
 187
 188 /* Dissect a single MQTT-SN packet. */
 189 // NOLINTNEXTLINE(misc-no-recursion)
 190 static void dissect_mqttsn_packet(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, int offset)
 191 {
 192     /* Various variables. */
 193     int long_hdr_len = 0;
 194     uint8_t mqttsn_msg_type_id;
 195     uint16_t mqttsn_msg_len;
 196
 197     /* Get the message length. */
 198     mqttsn_msg_len = tvb_get_uint8(tvb, offset);
 199
 200     /* If the message length is equal to 1 then the next two bytes define the real message length. */
 201     if (mqttsn_msg_len == 1)
 202     {
 203         long_hdr_len = 1;
 204         mqttsn_msg_len = tvb_get_ntohs(tvb, offset + 1);
 205     }
 206
 207     /* If this is an encapsulated message, we need to add the offset of the previous packet. */
 208     mqttsn_msg_len += offset;
 209
 210     /* Get the message type id (in byte 1 or 3 - depending on the message length). */
 211     mqttsn_msg_type_id = tvb_get_uint8(tvb, offset + (long_hdr_len ? 3 : 1));
 212
 213     if (tree)
 214     {
 215         /* Variables for the message items and trees. */
 216         proto_item *ti = NULL;
 217         proto_item *ti_mqttsn = NULL;
 218         proto_tree *mqttsn_tree = NULL;
 219         proto_tree *mqttsn_msg_tree = NULL;
 220         proto_tree *mqttsn_flag_tree = NULL;
 221
 222         /* Add MQTT-SN subtree to the main tree. */
 223         if (offset == 0)
 224         {
 225             ti = proto_tree_add_item(tree, proto_mqttsn, tvb, 0, -1, ENC_NA);
 226             mqttsn_tree = proto_item_add_subtree(ti, ett_mqttsn_hdr);
 227         }
 228         /* If this is an encapsulated message, we add the message to the existing subtree. */
 229         else
 230         {
 231             mqttsn_tree = tree;
 232         }
 233
 234         /* Add message subtree. */
 235         ti_mqttsn = proto_tree_add_item(mqttsn_tree, hf_mqttsn_msg, tvb, offset + (long_hdr_len ? 3 : 1), -1, ENC_NA);
 236         mqttsn_msg_tree = proto_item_add_subtree(ti_mqttsn, ett_mqttsn_msg);
 237
 238         /* | Message type (1 octet) | */
 239         proto_tree_add_item(mqttsn_msg_tree, hf_mqttsn_msg_type, tvb, offset + (long_hdr_len ? 3 : 1), 1, ENC_BIG_ENDIAN);
 240         offset += 1;
 241
 242         /* | Message length (1 - 2 octets) | */
 243         proto_tree_add_item(mqttsn_msg_tree, hf_mqttsn_msg_len, tvb, offset - 1 + (long_hdr_len ? 1 : 0), (long_hdr_len ? 2 : 1), ENC_BIG_ENDIAN);
 244         offset += (long_hdr_len ? 3 : 1);
 245
 246         /*
 247          * Only some message types contain flags (1 octet).
 248          * ______________________________________________________________________________________
 249          * |         |           |            |          |                  |                   |
 250          * |  bit 7  | bit 6 + 5 |    bit 4   |   bit 3  |      bit 2       |     bit 1 + 0     |
 251          * |   DUP   |    QoS    |   Retain   |   Will   |   CleanSession   |    TopicIdType    |
 252          * |_________|___________|____________|__________|__________________|___________________|
 253          */
 254         switch (mqttsn_msg_type_id)
 255         {
 256             /* Connect */
 257             case MQTTSN_CONNECT:
 258                 /* Add Will, CleanSession and Topic ID Type flags. */
 259                 mqttsn_flag_tree = proto_item_add_subtree(ti_mqttsn, ett_mqttsn_flags);
 260                 proto_tree_add_item(mqttsn_flag_tree, hf_mqttsn_will, tvb, offset, 1, ENC_BIG_ENDIAN);
 261                 proto_tree_add_item(mqttsn_flag_tree, hf_mqttsn_clean_session, tvb, offset, 1, ENC_BIG_ENDIAN);
 262                 proto_tree_add_item(mqttsn_flag_tree, hf_mqttsn_topic_id_type, tvb, offset, 1, ENC_BIG_ENDIAN);
 263                 offset += 1;
 264                 break;
 265
 266             /* Publish */
 267             case MQTTSN_PUBLISH:
 268                 /* Add DUP, QoS, Retain and Topic ID Type flags. */
 269                 mqttsn_flag_tree = proto_item_add_subtree(ti_mqttsn, ett_mqttsn_flags);
 270                 proto_tree_add_item(mqttsn_flag_tree, hf_mqttsn_dup, tvb, offset, 1, ENC_BIG_ENDIAN);
 271                 proto_tree_add_item(mqttsn_flag_tree, hf_mqttsn_qos, tvb, offset, 1, ENC_BIG_ENDIAN);
 272                 proto_tree_add_item(mqttsn_flag_tree, hf_mqttsn_retain, tvb, offset, 1, ENC_BIG_ENDIAN);
 273                 proto_tree_add_item(mqttsn_flag_tree, hf_mqttsn_topic_id_type, tvb, offset, 1, ENC_BIG_ENDIAN);
 274                 offset += 1;
 275                 break;
 276
 277             /* Will Topic + Subscribe + Subscribe Acknowledgement + Unsubscribe + Will Topic Update */
 278             case MQTTSN_WILLTOPIC:
 279             case MQTTSN_SUBSCRIBE:
 280             case MQTTSN_SUBACK:
 281             case MQTTSN_UNSUBSCRIBE:
 282             case MQTTSN_WILLTOPICUPD:
 283                 /* Add Topic ID Type flag. */
 284                 mqttsn_flag_tree = proto_item_add_subtree(ti_mqttsn, ett_mqttsn_flags);
 285                 proto_tree_add_item(mqttsn_flag_tree, hf_mqttsn_topic_id_type, tvb, offset, 1, ENC_BIG_ENDIAN);
 286                 offset += 1;
 287                 break;
 288
 289             /* Default Case */
 290             default:
 291                 break;
 292         }
 293
 294         /* Add message specific informations. */
 295         switch (mqttsn_msg_type_id)
 296         {
 297             /* Advertise Gateway */
 298             case MQTTSN_ADVERTISE:
 299                 /* | 1 - Gateway ID | 2,3 - Duration until next Advertise | */
 300                 proto_tree_add_item(mqttsn_msg_tree, hf_mqttsn_gw_id, tvb, offset, 1, ENC_BIG_ENDIAN);
 301                 offset += 1;
 302                 proto_tree_add_item(mqttsn_msg_tree, hf_mqttsn_adv_interv, tvb, offset, 2, ENC_BIG_ENDIAN);
 303                 break;
 304
 305             /* Search Gateway */
 306             case MQTTSN_SEARCHGW:
 307                 /* | 1 - Broadcast Radius | */
 308                 proto_tree_add_item(mqttsn_msg_tree, hf_mqttsn_radius, tvb, offset, 1, ENC_BIG_ENDIAN);
 309                 break;
 310
 311             /* Gateway Information */
 312             case MQTTSN_GWINFO:
 313                 /* | 1 - Gateway ID | 2:n - Gateway Address (optional) | */
 314                 proto_tree_add_item(mqttsn_msg_tree, hf_mqttsn_gw_id, tvb, offset, 1, ENC_BIG_ENDIAN);
 315                 offset += 1;
 316
 317                 /* Gateway Address is only present if message is sent by client. */
 318                 if (offset < mqttsn_msg_len)
 319                 {
 320                     proto_tree_add_item(mqttsn_msg_tree, hf_mqttsn_gw_addr, tvb, offset, (mqttsn_msg_len - offset), ENC_ASCII);
 321                 }
 322                 break;
 323
 324             /* Connect */
 325             case MQTTSN_CONNECT:
 326                 /* | 1 - Protocol ID | 2,3 - Keep Alive Duration | 4:n - Client ID | */
 327                 proto_tree_add_item(mqttsn_msg_tree, hf_mqttsn_protocol_id, tvb, offset, 1, ENC_BIG_ENDIAN);
 328                 offset += 1;
 329                 proto_tree_add_item(mqttsn_msg_tree, hf_mqttsn_keep_alive, tvb, offset, 2, ENC_BIG_ENDIAN);
 330                 offset += 2;
 331                 proto_tree_add_item(mqttsn_msg_tree, hf_mqttsn_client_id, tvb, offset, (mqttsn_msg_len - offset), ENC_ASCII);
 332                 break;
 333
 334             /* Connection Acknowledgement */
 335             case MQTTSN_CONNACK:
 336                 /* | 1 - Return code | */
 337                 proto_tree_add_item(mqttsn_msg_tree, hf_mqttsn_return_code, tvb, offset, 1, ENC_BIG_ENDIAN);
 338                 break;
 339
 340             /* Will Topic Request + Will Message Request */
 341             case MQTTSN_WILLTOPICREQ:
 342             case MQTTSN_WILLMSGREQ:
 343                 /* Will topic/message requests don't have a variable header. */
 344                 break;
 345
 346             /* Will Topic */
 347             case MQTTSN_WILLTOPIC:
 348                 /* | 1:n - Will topic | */
 349                 proto_tree_add_item(mqttsn_msg_tree, hf_mqttsn_will_topic, tvb, offset, (mqttsn_msg_len - offset), ENC_ASCII);
 350                 break;
 351
 352             /* Will Message */
 353             case MQTTSN_WILLMSG:
 354                 /* | 1:n - Will message | */
 355                 proto_tree_add_item(mqttsn_msg_tree, hf_mqttsn_will_msg, tvb, offset, (mqttsn_msg_len - offset), ENC_ASCII);
 356                 break;
 357
 358             /* Register */
 359             case MQTTSN_REGISTER:
 360                 /* | 1,2 - Topic ID | 3,4 - Message ID | 5:n - Topic name | */
 361                 proto_tree_add_item(mqttsn_msg_tree, hf_mqttsn_topic_id, tvb, offset, 2, ENC_BIG_ENDIAN);
 362                 offset += 2;
 363                 proto_tree_add_item(mqttsn_msg_tree, hf_mqttsn_msg_id, tvb, offset, 2, ENC_BIG_ENDIAN);
 364                 offset += 2;
 365                 proto_tree_add_item(mqttsn_msg_tree, hf_mqttsn_topic, tvb, offset, (mqttsn_msg_len - offset), ENC_ASCII);
 366                 break;
 367
 368             /* Register Acknowledgement */
 369             case MQTTSN_REGACK:
 370                 /* | 1,2 - Topic ID | 3,4 - Message ID | 5 - Return code | */
 371                 proto_tree_add_item(mqttsn_msg_tree, hf_mqttsn_topic_id, tvb, offset, 2, ENC_BIG_ENDIAN);
 372                 offset += 2;
 373                 proto_tree_add_item(mqttsn_msg_tree, hf_mqttsn_msg_id, tvb, offset, 2, ENC_BIG_ENDIAN);
 374                 offset += 2;
 375                 proto_tree_add_item(mqttsn_msg_tree, hf_mqttsn_return_code, tvb, offset, 1, ENC_BIG_ENDIAN);
 376                 break;
 377
 378             /* Publish */
 379             case MQTTSN_PUBLISH:
 380                 /* | 1,2 - Topic ID | 3,4 - Message ID | 5:n - Publish data | */
 381                 proto_tree_add_item(mqttsn_msg_tree, hf_mqttsn_topic_id, tvb, offset, 2, ENC_BIG_ENDIAN);
 382                 offset += 2;
 383                 proto_tree_add_item(mqttsn_msg_tree, hf_mqttsn_msg_id, tvb, offset, 2, ENC_BIG_ENDIAN);
 384                 offset += 2;
 385                 proto_tree_add_item(mqttsn_msg_tree, hf_mqttsn_pub_msg, tvb, offset, (mqttsn_msg_len - offset), ENC_ASCII);
 386                 break;
 387
 388             /* Publish Acknowledgement */
 389             case MQTTSN_PUBACK:
 390                 /* | 1,2 - Topic ID | 3,4 - Message ID | 5 - Return code | */
 391                 proto_tree_add_item(mqttsn_msg_tree, hf_mqttsn_topic_id, tvb, offset, 2, ENC_BIG_ENDIAN);
 392                 offset += 2;
 393                 proto_tree_add_item(mqttsn_msg_tree, hf_mqttsn_msg_id, tvb, offset, 2, ENC_BIG_ENDIAN);
 394                 offset += 2;
 395                 proto_tree_add_item(mqttsn_msg_tree, hf_mqttsn_return_code, tvb, offset, 1, ENC_BIG_ENDIAN);
 396                 break;
 397
 398             /* Publish Complete + Publish Received + Publish Released */
 399             case MQTTSN_PUBCOMP:
 400             case MQTTSN_PUBREC:
 401             case MQTTSN_PUBREL:
 402                 /* | 1,2 - Message ID | */
 403                 proto_tree_add_item(mqttsn_msg_tree, hf_mqttsn_msg_id, tvb, offset, 2, ENC_BIG_ENDIAN);
 404                 break;
 405
 406             /* Subscribe + Unsubscribe */
 407             case MQTTSN_SUBSCRIBE:
 408             case MQTTSN_UNSUBSCRIBE:
 409                 /* | 1,2 - Message ID | 5:n - Topic name _OR_ 5,6 - Topic ID | */
 410                 proto_tree_add_item(mqttsn_msg_tree, hf_mqttsn_msg_id, tvb, offset, 2, ENC_BIG_ENDIAN);
 411                 offset += 2;
 412                 proto_tree_add_item(mqttsn_msg_tree, hf_mqttsn_topic_name_or_id, tvb, offset, (mqttsn_msg_len - offset), ENC_ASCII);
 413                 break;
 414
 415             /* Subscribe Acknowledgment */
 416             case MQTTSN_SUBACK:
 417                 /* | 1,2 - Topic ID | 3,4 - Message ID | 5 - Return code | */
 418                 proto_tree_add_item(mqttsn_msg_tree, hf_mqttsn_topic_id, tvb, offset, 2, ENC_BIG_ENDIAN);
 419                 offset += 2;
 420                 proto_tree_add_item(mqttsn_msg_tree, hf_mqttsn_msg_id, tvb, offset, 2, ENC_BIG_ENDIAN);
 421                 offset += 2;
 422                 proto_tree_add_item(mqttsn_msg_tree, hf_mqttsn_return_code, tvb, offset, 1, ENC_BIG_ENDIAN);
 423                 break;
 424
 425             /* Unsubscribe Acknowledgement */
 426             case MQTTSN_UNSUBACK:
 427                 /* | 1,2 - Message ID | */
 428                 proto_tree_add_item(mqttsn_msg_tree, hf_mqttsn_msg_id, tvb, offset, 2, ENC_BIG_ENDIAN);
 429                 break;
 430
 431             /* Ping Request */
 432             case MQTTSN_PINGREQ:
 433                 /* | 1:n - Client ID (optional) | */
 434                 if (offset < mqttsn_msg_len)
 435                 {
 436                     proto_tree_add_item(mqttsn_msg_tree, hf_mqttsn_client_id, tvb, offset, (mqttsn_msg_len - offset), ENC_ASCII);
 437                 }
 438                 break;
 439
 440             /* Ping Response */
 441             case MQTTSN_PINGRESP:
 442                 /* Ping responses don't have a variable header. */
 443                 break;
 444
 445             /* Disconnect */
 446             case MQTTSN_DISCONNECT:
 447                 /* | 1,2 - Sleep Time Duration (optional) | */
 448                 if (offset < mqttsn_msg_len)
 449                 {
 450                     proto_tree_add_item(mqttsn_msg_tree, hf_mqttsn_sleep_timer, tvb, offset, 2, ENC_BIG_ENDIAN);
 451                 }
 452                 break;
 453
 454             /* Will Topic Update */
 455             case MQTTSN_WILLTOPICUPD:
 456                 /* | 1:n - Will topic | */
 457                 proto_tree_add_item(mqttsn_msg_tree, hf_mqttsn_will_topic, tvb, offset, (mqttsn_msg_len - offset), ENC_ASCII);
 458                 break;
 459
 460             /* Will Message Update */
 461             case MQTTSN_WILLMSGUPD:
 462                 /* | 1:n - Will message | */
 463                 proto_tree_add_item(mqttsn_msg_tree, hf_mqttsn_will_msg, tvb, offset, (mqttsn_msg_len - offset), ENC_ASCII);
 464                 break;
 465
 466             /* Will Topic Response + Will Message Response */
 467             case MQTTSN_WILLTOPICRESP:
 468             case MQTTSN_WILLMSGRESP:
 469                 /* | 1 - Return code | */
 470                 proto_tree_add_item(mqttsn_msg_tree, hf_mqttsn_return_code, tvb, offset, 1, ENC_BIG_ENDIAN);
 471                 break;
 472
 473             case MQTTSN_ENCAPSULATED_MSG:
 474                 /* | 1 - Control information | 2:n - Wireless Node ID | n+1:m - MQTT-SN message | */
 475                 proto_tree_add_item(mqttsn_msg_tree, hf_mqttsn_control_info, tvb, offset, 1, ENC_BIG_ENDIAN);
 476                 offset += 1;
 477                 proto_tree_add_item(mqttsn_msg_tree, hf_mqttsn_wireless_node_id, tvb, offset, (mqttsn_msg_len - offset), ENC_BIG_ENDIAN);
 478                 offset += (mqttsn_msg_len - offset);
 479
 480                 /* Dissect encapsulated message (if present). */
 481                 if (tvb_reported_length_remaining(tvb, offset) > 0)
 482                 {
 483                     increment_dissection_depth(pinfo);
 484                     dissect_mqttsn_packet(tvb, pinfo, mqttsn_msg_tree, offset);
 485                     decrement_dissection_depth(pinfo);
 486                 }
 487
 488             /* Default Case */
 489             default:
 490                 break;
 491         }
 492     }
 493 }
 494
 495 /* Dissect a complete MQTT-SN message. */
 496 static int dissect_mqttsn(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
 497 {
 498     /* Various variables. */
 499     int offset = 0;
 500     uint8_t mqttsn_msg_type_id;
 501
 502     /*
 503      * If the value in byte 0 is unequal to 1 then the value defines the
 504      * message length and the message type id is contained in byte 1.
 505      */
 506     if (tvb_get_uint8(tvb, 0) != 1)
 507     {
 508         mqttsn_msg_type_id = tvb_get_uint8(tvb, 1);
 509     }
 510     /*
 511      * If the value in byte 0 is equal to 1 then the next two bytes define
 512      * the real message length and the message type id is contained in byte 3.
 513      */
 514     else
 515     {
 516         mqttsn_msg_type_id = tvb_get_uint8(tvb, 3);
 517     }
 518
 519     /* Add the protcol name to the protocol column. */
 520     col_set_str(pinfo->cinfo, COL_PROTOCOL, "MQTT-SN");
 521
 522     /* Add the message type to the info column. */
 523     col_clear(pinfo->cinfo, COL_INFO);
 524     col_add_str(pinfo->cinfo, COL_INFO, val_to_str_ext(mqttsn_msg_type_id, &mqttsn_msgtype_vals_ext, "Unknown (0x%02x)"));
 525
 526     /* Dissect a MQTT-SN packet. */
 527     dissect_mqttsn_packet(tvb, pinfo, tree, offset);
 528     return tvb_captured_length(tvb);
 529 }
 530
 531 /* Register the protocol with Wireshark. */
 532 void proto_register_mqttsn(void)
 533 {
 534     static hf_register_info hf_mqttsn[] = {
 535         { &hf_mqttsn_msg,
 536             { "Message", "mqttsn.msg",
 537                 FT_NONE, BASE_NONE, NULL, 0,
 538                 NULL, HFILL }
 539         },
 540         { &hf_mqttsn_msg_len,
 541             { "Message Length", "mqttsn.msg.len",
 542                 FT_UINT16, BASE_DEC, NULL, 0x0,
 543                 NULL, HFILL }
 544         },
 545         { &hf_mqttsn_msg_type,
 546             { "Message Type", "mqttsn.msg.type",
 547                 FT_UINT8, BASE_HEX | BASE_EXT_STRING, &mqttsn_msgtype_vals_ext, 0,
 548                 NULL, HFILL }
 549         },
 550         { &hf_mqttsn_dup,
 551             { "DUP", "mqttsn.dup",
 552                 FT_BOOLEAN, 8, TFS(&tfs_yes_no), MQTTSN_MASK_DUP_FLAG,
 553                 NULL, HFILL }
 554         },
 555         { &hf_mqttsn_will,
 556             { "Will", "mqttsn.will",
 557                 FT_BOOLEAN, 8, TFS(&tfs_yes_no), MQTTSN_MASK_WILL,
 558                 NULL, HFILL }
 559         },
 560         { &hf_mqttsn_clean_session,
 561             { "Clean Session", "mqttsn.clean.session",
 562                 FT_BOOLEAN, 8, TFS(&tfs_yes_no), MQTTSN_MASK_CLEAN,
 563                 NULL, HFILL }
 564         },
 565         { &hf_mqttsn_topic_id_type,
 566             { "Topic ID Type", "mqttsn.topic.id.type",
 567                 FT_UINT8, BASE_HEX, VALS(mqttsn_typeid_vals), MQTTSN_MASK_TOPIC_ID_TYPE,
 568                 NULL, HFILL }
 569         },
 570         { &hf_mqttsn_qos,
 571             { "QoS", "mqttsn.qos",
 572                 FT_UINT8, BASE_HEX, VALS(mqttsn_qos_vals), MQTTSN_MASK_QOS,
 573                 NULL, HFILL }
 574         },
 575         { &hf_mqttsn_retain,
 576             { "Retain", "mqttsn.retain",
 577                 FT_BOOLEAN, 8, TFS(&tfs_yes_no), MQTTSN_MASK_RETAIN,
 578                 NULL, HFILL }
 579         },
 580         { &hf_mqttsn_return_code,
 581             { "Return Code", "mqttsn.return.code",
 582                 FT_UINT8, BASE_HEX, VALS(mqttsn_return_vals), 0x0,
 583                 NULL, HFILL }
 584         },
 585         { &hf_mqttsn_gw_id,
 586             { "Gateway ID", "mqttsn.gw.id",
 587                 FT_UINT8, BASE_DEC, NULL, 0x0,
 588                 NULL, HFILL }
 589         },
 590         { &hf_mqttsn_gw_addr,
 591             { "Gateway Address", "mqttsn.gw.addr",
 592                 FT_STRING, BASE_NONE, NULL, 0x0,
 593                 NULL, HFILL }
 594         },
 595         { &hf_mqttsn_adv_interv,
 596             { "Advertise Interval", "mqttsn.adv.interv",
 597                 FT_UINT16, BASE_DEC, NULL, 0x0,
 598                 NULL, HFILL }
 599         },
 600         { &hf_mqttsn_radius,
 601             { "Broadcast Radius", "mqttsn.radius",
 602                 FT_UINT8, BASE_DEC, NULL, 0x0,
 603                 NULL, HFILL }
 604         },
 605         { &hf_mqttsn_protocol_id,
 606             { "Protocol ID", "mqttsn.protocol.id",
 607                 FT_UINT8, BASE_HEX, NULL, 0x0,
 608                 NULL, HFILL }
 609         },
 610         { &hf_mqttsn_topic_id,
 611             { "Topic ID", "mqttsn.topic.id",
 612                 FT_UINT16, BASE_DEC, NULL, 0x0,
 613                 NULL, HFILL }
 614         },
 615         { &hf_mqttsn_msg_id,
 616             { "Message ID", "mqttsn.msg.id",
 617                 FT_UINT16, BASE_DEC, NULL, 0x0,
 618                 NULL, HFILL }
 619         },
 620         { &hf_mqttsn_topic,
 621             { "Topic Name", "mqttsn.topic",
 622                 FT_STRING, BASE_NONE, NULL, 0x0,
 623                 NULL, HFILL }
 624         },
 625         { &hf_mqttsn_topic_name_or_id,
 626             { "Topic Name/ID", "mqttsn.topic.name.or.id",
 627                 FT_STRING, BASE_NONE, NULL, 0x0,
 628                 NULL, HFILL }
 629         },
 630         { &hf_mqttsn_sleep_timer,
 631             { "Sleep Timer", "mqttsn.sleep.timer",
 632                 FT_UINT16, BASE_DEC, NULL, 0x0,
 633                 NULL, HFILL }
 634         },
 635         { &hf_mqttsn_will_topic,
 636             { "Will Topic", "mqttsn.will.topic",
 637                 FT_STRING, BASE_NONE, NULL, 0x0,
 638                 NULL, HFILL }
 639         },
 640         { &hf_mqttsn_will_msg,
 641             { "Will Message", "mqttsn.will.msg",
 642                 FT_STRING, BASE_NONE, NULL, 0x0,
 643                 NULL, HFILL }
 644         },
 645         { &hf_mqttsn_pub_msg,
 646             { "Message", "mqttsn.pub.msg",
 647                 FT_STRING, BASE_NONE, NULL, 0x0,
 648                 NULL, HFILL }
 649         },
 650         { &hf_mqttsn_client_id,
 651             { "Client ID", "mqttsn.client.id",
 652                 FT_STRING, BASE_NONE, NULL, 0x0,
 653                 NULL, HFILL }
 654         },
 655         { &hf_mqttsn_keep_alive,
 656             { "Keep Alive", "mqttsn.keep.alive",
 657                 FT_UINT16, BASE_DEC, NULL, 0x0,
 658                 NULL, HFILL }
 659         },
 660         { &hf_mqttsn_control_info,
 661             { "Control", "mqttsn.control.info",
 662                 FT_UINT8, BASE_HEX, NULL, MQTTSN_MASK_CONTROL,
 663                 NULL, HFILL }
 664         },
 665         { &hf_mqttsn_wireless_node_id,
 666             { "Wireless Node ID", "mqttsn.wireless.node.id",
 667                 FT_UINT16, BASE_DEC, NULL, 0x0,
 668                 NULL, HFILL }
 669         }
 670     };
 671
 672     /* Setup protocol subtree arrays. */
 673     static int* ett_mqttsn[] = {
 674         &ett_mqttsn_hdr,
 675         &ett_mqttsn_msg,
 676         &ett_mqttsn_flags
 677     };
 678
 679     /* Register protocol names and descriptions. */
 680     proto_mqttsn = proto_register_protocol("MQ Telemetry Transport Protocol for Sensor Networks", "MQTT-SN", "mqttsn");
 681
 682     /* Create the dissector handle. */
 683     mqttsn_handle = register_dissector("mqttsn", dissect_mqttsn, proto_mqttsn);
 684
 685     /* Register fields and subtrees. */
 686     proto_register_field_array(proto_mqttsn, hf_mqttsn, array_length(hf_mqttsn));
 687     proto_register_subtree_array(ett_mqttsn, array_length(ett_mqttsn));
 688 }
 689
 690 /* Dissector Handoff */
 691 void proto_reg_handoff_mqttsn(void)
 692 {
 693     dissector_add_for_decode_as_with_preference("udp.port", mqttsn_handle);
 694 }
 695
 696 /*
 697  * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
 698  *
 699  * Local variables:
 700  * c-basic-offset: 4
 701  * tab-width: 8
 702  * indent-tabs-mode: nil
 703  * End:
 704  *
 705  * vi: set shiftwidth=4 tabstop=8 expandtab:
 706  * :indentSize=4:tabSize=8:noTabs=true:
 707  */