epan/dissectors/packet-pcomtcp.c

   1 /* packet-pcomtcp.c
   2  * Routines for PCOM/TCP dissection
   3  * Copyright 2018, Luis Rosa <lmrosa@dei.uc.pt>
   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
  12 /*
  13  * PCOM is a protocol to communicate with Unitronics PLCs either by serial or TCP.
  14  * Two modes are available, ASCII and Binary.
  15  *
  16  * See https://unitronicsplc.com/Download/SoftwareUtilities/Unitronics%20PCOM%20Protocol.pdf
  17  *
  18  */
  19
  20 #include <config.h>
  21 #include <epan/packet.h>
  22 #include <epan/expert.h>
  23
  24 void proto_reg_handoff_pcomtcp(void);
  25 void proto_register_pcomtcp(void);
  26
  27 /* Initialize the protocol and registered fields */
  28 static int proto_pcomtcp;
  29 static int proto_pcomascii;
  30 static int proto_pcombinary;
  31
  32 static int hf_pcomtcp_transid;
  33 static int hf_pcomtcp_protocol;
  34 static int hf_pcomtcp_reserved;
  35 static int hf_pcomtcp_length;
  36
  37 static int hf_pcomascii_stx;
  38 static int hf_pcomascii_unitid;
  39 static int hf_pcomascii_command_code;
  40 static int hf_pcomascii_address;
  41 static int hf_pcomascii_length;
  42 static int hf_pcomascii_address_value;
  43 static int hf_pcomascii_command;
  44 static int hf_pcomascii_checksum;
  45 static int hf_pcomascii_etx;
  46
  47 static int hf_pcombinary_stx;
  48 static int hf_pcombinary_id;
  49 static int hf_pcombinary_reserved1;
  50 static int hf_pcombinary_reserved2;
  51 static int hf_pcombinary_reserved3;
  52 static int hf_pcombinary_command;
  53 static int hf_pcombinary_reserved4;
  54 static int hf_pcombinary_command_specific;
  55 static int hf_pcombinary_data_length;
  56 static int hf_pcombinary_header_checksum;
  57 static int hf_pcombinary_data;
  58 static int hf_pcombinary_footer_checksum;
  59 static int hf_pcombinary_etx;
  60
  61 static expert_field ei_pcomtcp_reserved_bad_value;
  62 static expert_field ei_pcomascii_command_unsupported;
  63 static expert_field ei_pcombinary_reserved1_bad_value;
  64 static expert_field ei_pcombinary_reserved2_bad_value;
  65 static expert_field ei_pcombinary_reserved3_bad_value;
  66 static expert_field ei_pcombinary_reserved4_bad_value;
  67 static expert_field ei_pcombinary_command_unsupported;
  68
  69 /* Initialize the subtree pointers */
  70 static int ett_pcomtcp;
  71 static int ett_pcomascii;
  72 static int ett_pcombinary;
  73
  74 static dissector_handle_t pcomtcp_handle;
  75 static dissector_handle_t pcomascii_handle;
  76 static dissector_handle_t pcombinary_handle;
  77
  78 /* PCOM/TCP definitions */
  79 #define PCOMTCP_MIN_LENGTH 6
  80 #define PCOMTCP_TCP_PORT 20256
  81 #define PCOM_ASCII 101
  82 #define PCOM_BINARY 102
  83
  84 static range_t *global_pcomtcp_tcp_ports; /* Port 20256, by default */
  85
  86 /* Translate pcomp_protocol to string */
  87 static const value_string pcomp_protocol_vals[] = {
  88     { PCOM_ASCII,          "ASCII mode" },
  89     { PCOM_BINARY,         "Binary mode" },
  90     { 0,                    NULL },
  91 };
  92
  93 #define PCOMASCII_ID_COMMAND                0x4944    // "ID"
  94 #define PCOMASCII_START_COMMAND             0x434352  // "CCR"
  95 #define PCOMASCII_STOP_COMMAND              0x434353  // "CCS"
  96 #define PCOMASCII_RESET_COMMAND             0x434345  // "CCE"
  97 #define PCOMASCII_INIT_COMMAND              0x434349  // "CCI"
  98 #define PCOMASCII_REPLY_ADMIN_COMMAND       0x4343    // "CC"
  99 #define PCOMASCII_GET_UNITID                0x5547    // "UG"
 100 #define PCOMASCII_SET_UNITID                0x5553    // "US"
 101 #define PCOMASCII_GET_RTC                   0x5243    // "RC"
 102 #define PCOMASCII_SET_RTC                   0x5343    // "SC"
 103 #define PCOMASCII_READ_INPUTS               0x5245    // "RE"
 104 #define PCOMASCII_READ_OUTPUTS              0x5241    // "RA"
 105 #define PCOMASCII_READ_SYSTEM_BITS          0x4753    // "GS"
 106 #define PCOMASCII_READ_SYSTEM_INTEGERS      0x4746    // "GF"
 107 #define PCOMASCII_READ_SYSTEM_LONGS         0x524e48  // "RNH"
 108 #define PCOMASCII_READ_SYSTEM_DOUBLE_WORDS  0x524e4a  // "RNJ"
 109 #define PCOMASCII_READ_MEMORY_BITS          0x5242    // "RB"
 110 #define PCOMASCII_READ_MEMORY_INTEGERS      0x5257    // "RW"
 111 #define PCOMASCII_READ_MEMORY_LONGS         0x524e4c  // "RNL"
 112 #define PCOMASCII_READ_MEMORY_DOUBLE_WORDS  0x524e44  // "RND"
 113 #define PCOMASCII_READ_LONGS                0x524e    // "RN"
 114 #define PCOMASCII_WRITE_OUTPUTS             0x5341    // "SA"
 115 #define PCOMASCII_WRITE_SYSTEM_BITS         0x5353    // "SS"
 116 #define PCOMASCII_WRITE_SYSTEM_INTEGERS     0x5346    // "SF"
 117 #define PCOMASCII_WRITE_SYSTEM_LONGS        0x534e48  // "SNH"
 118 #define PCOMASCII_WRITE_SYSTEM_DOUBLE_WORDS 0x534e4a  // "SNJ"
 119 #define PCOMASCII_WRITE_MEMORY_BITS         0x5342    // "SB"
 120 #define PCOMASCII_WRITE_MEMORY_INTEGERS     0x5357    // "SW"
 121 #define PCOMASCII_WRITE_MEMORY_LONGS        0x534e4c  // "SNL"
 122 #define PCOMASCII_WRITE_MEMORY_DOUBLE_WORDS 0x534e44  // "SND"
 123 #define PCOMASCII_WRITE_LONGS               0x534e    // "SN"
 124
 125 #define PCOMBINARY_GET_PLC_NAME_REQUEST     0x0c
 126 #define PCOMBINARY_GET_PLC_NAME_REPLY       0x8c
 127 #define PCOMBINARY_READ_OPERANDS_REQUEST    0x4d
 128 #define PCOMBINARY_READ_OPERANDS_REPLY      0xcd
 129 #define PCOMBINARY_READ_DATA_TABLE_REQUEST  0x04
 130 #define PCOMBINARY_READ_DATA_TABLE_REPLY    0x84
 131 #define PCOMBINARY_WRITE_DATA_TABLE_REQUEST 0x44
 132 #define PCOMBINARY_WRITE_DATA_TABLE_REPLY   0xc4
 133
 134 /* Translate pcomascii_command_code to string */
 135 static const value_string pcomascii_cc_vals[] = {
 136     { PCOMASCII_ID_COMMAND,               "Send Identification Command" },
 137     { PCOMASCII_START_COMMAND,            "Send Start Command" },
 138     { PCOMASCII_STOP_COMMAND,             "Send Stop Command" },
 139     { PCOMASCII_RESET_COMMAND,            "Send Reset Command" },
 140     { PCOMASCII_INIT_COMMAND,             "Send Init Command" },
 141     { PCOMASCII_REPLY_ADMIN_COMMAND,      "Reply of Admin Commands (CC*)" },
 142     { PCOMASCII_GET_UNITID,               "Get UnitID" },
 143     { PCOMASCII_SET_UNITID,               "Set UnitID" },
 144     { PCOMASCII_GET_RTC,                  "Get RTC" },
 145     { PCOMASCII_SET_RTC,                  "Set RTC" },
 146     { PCOMASCII_READ_INPUTS,              "Read Inputs" },
 147     { PCOMASCII_READ_OUTPUTS,             "Read Outputs" },
 148     { PCOMASCII_READ_SYSTEM_BITS,         "Read System Bits" },
 149     { PCOMASCII_READ_SYSTEM_INTEGERS,     "Read System Integers" },
 150     { PCOMASCII_READ_SYSTEM_LONGS,        "Read System Longs" },
 151     { PCOMASCII_READ_SYSTEM_DOUBLE_WORDS, "Read System Double Words" },
 152     { PCOMASCII_READ_MEMORY_BITS,         "Read Memory Bits" },
 153     { PCOMASCII_READ_MEMORY_INTEGERS,     "Read Memory Integers" },
 154     { PCOMASCII_READ_MEMORY_LONGS,        "Read Memory Longs" },
 155     { PCOMASCII_READ_MEMORY_DOUBLE_WORDS, "Read Memory Double Words" },
 156     { PCOMASCII_READ_LONGS,               "Read Longs / Double Words" },
 157     { PCOMASCII_WRITE_OUTPUTS,            "Write Outputs" },
 158     { PCOMASCII_WRITE_SYSTEM_BITS,        "Write System Bits" },
 159     { PCOMASCII_WRITE_SYSTEM_INTEGERS,    "Write System Integers" },
 160     { PCOMASCII_WRITE_SYSTEM_LONGS,       "Write System Longs" },
 161     { PCOMASCII_WRITE_SYSTEM_DOUBLE_WORDS,"Write System Double Words" },
 162     { PCOMASCII_WRITE_MEMORY_BITS,        "Write Memory Bits" },
 163     { PCOMASCII_WRITE_MEMORY_INTEGERS,    "Write Memory Integers" },
 164     { PCOMASCII_WRITE_MEMORY_LONGS,       "Write Memory Longs" },
 165     { PCOMASCII_WRITE_MEMORY_DOUBLE_WORDS,"Write Memory Double Words" },
 166     { PCOMASCII_WRITE_LONGS,              "Write Longs / Double Words" },
 167     { 0,                        NULL },
 168 };
 169
 170 /* Translate pcombinary_command requests to string */
 171 static const value_string pcombinary_command_vals_request[] = {
 172     { PCOMBINARY_GET_PLC_NAME_REQUEST,            "Get PLC Name Request" },
 173     { PCOMBINARY_READ_OPERANDS_REQUEST,           "Read Operands Request" },
 174     { PCOMBINARY_READ_DATA_TABLE_REQUEST,         "Read Data Table Request" },
 175     { PCOMBINARY_WRITE_DATA_TABLE_REQUEST,        "Write Data Table Request" },
 176     { 0,                        NULL },
 177 };
 178
 179 /* Translate pcombinary_command reply to string */
 180 static const value_string pcombinary_command_vals_reply[] = {
 181     { PCOMBINARY_GET_PLC_NAME_REPLY,            "Get PLC Name Reply" },
 182     { PCOMBINARY_READ_OPERANDS_REPLY,           "Read Operands Reply" },
 183     { PCOMBINARY_READ_DATA_TABLE_REPLY,         "Read Data Table Reply" },
 184     { PCOMBINARY_WRITE_DATA_TABLE_REPLY,        "Write Data Table Reply" },
 185     { 0,                        NULL },
 186 };
 187
 188
 189 /* Code to actually dissect the packets */
 190 static int
 191 dissect_pcomtcp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
 192         void *data _U_)
 193 {
 194     /* Set up structures needed to add the protocol subtree and manage it */
 195     proto_item  *ti;
 196     proto_tree  *pcomtcp_tree;
 197
 198     tvbuff_t    *next_tvb;
 199
 200     unsigned     offset = 0;
 201     const char   *pkt_type;
 202     uint8_t      pcom_mode;
 203     const char   *pcom_mode_str;
 204
 205     proto_item    *hf_pcomtcp_reserved_item = NULL;
 206
 207     /* Check that the packet is long enough for it to belong to us. */
 208     if (tvb_reported_length(tvb) < PCOMTCP_MIN_LENGTH)
 209         return 0;
 210
 211     pcom_mode = tvb_get_uint8(tvb, 2);
 212     if ( pcom_mode != PCOM_ASCII && pcom_mode != PCOM_BINARY )
 213         return 0;
 214
 215     pcom_mode_str = val_to_str(pcom_mode, pcomp_protocol_vals, "Unknown mode (%d)");
 216
 217     if (value_is_in_range(global_pcomtcp_tcp_ports, pinfo->srcport))
 218         pkt_type = "Reply";
 219     else
 220         pkt_type = "Query";
 221
 222     col_set_str(pinfo->cinfo, COL_PROTOCOL, "PCOM/TCP");
 223     col_clear(pinfo->cinfo, COL_INFO);
 224     col_add_fstr(pinfo->cinfo, COL_INFO, "%s in %s",
 225             pkt_type, pcom_mode_str);
 226
 227
 228     /* create display subtree for the protocol */
 229     ti = proto_tree_add_item(tree, proto_pcomtcp, tvb, 0, -1, ENC_NA);
 230     pcomtcp_tree = proto_item_add_subtree(ti, ett_pcomtcp);
 231
 232     proto_tree_add_item(pcomtcp_tree, hf_pcomtcp_transid, tvb,
 233             offset, 2, ENC_LITTLE_ENDIAN);
 234     offset += 2;
 235     proto_tree_add_item(pcomtcp_tree, hf_pcomtcp_protocol, tvb,
 236             offset, 1, ENC_NA);
 237     offset += 1;
 238     hf_pcomtcp_reserved_item = proto_tree_add_item(pcomtcp_tree, hf_pcomtcp_reserved, tvb,
 239             offset, 1, ENC_NA);
 240     if(tvb_get_uint8(tvb, offset) !=0){
 241             expert_add_info_format(pinfo, hf_pcomtcp_reserved_item,
 242                     &ei_pcomtcp_reserved_bad_value,"Isn't 0");
 243     }
 244     offset += 1;
 245     proto_tree_add_item(pcomtcp_tree, hf_pcomtcp_length, tvb,
 246             offset, 2, ENC_LITTLE_ENDIAN);
 247
 248     /* dissect the PCOM Data */
 249     offset += 2;
 250     next_tvb = tvb_new_subset_remaining(tvb, offset);
 251     if( tvb_reported_length_remaining(tvb, offset) > 0 ){
 252         if ( pcom_mode == PCOM_ASCII)
 253             call_dissector_with_data(pcomascii_handle, next_tvb, pinfo, tree, &pcom_mode);
 254         else
 255             call_dissector_with_data(pcombinary_handle, next_tvb, pinfo, tree, &pcom_mode);
 256     }
 257
 258     return tvb_reported_length(tvb);
 259 }
 260
 261 static int
 262 dissect_pcomascii(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
 263         void *data _U_)
 264 {
 265     /* Set up structures needed to add the protocol subtree and manage it */
 266     proto_item  *ti;
 267     proto_tree  *pcomascii_tree;
 268     proto_item    *hf_pcomascii_command_item = NULL;
 269
 270     unsigned     offset = 0;
 271     uint16_t     nvalues;
 272     uint8_t      i;
 273     uint8_t      cc_len;
 274     uint32_t     cc;
 275     const char* cc_str;
 276     const char* cc_str2;
 277     uint8_t      op_type;
 278     uint8_t      op_size;
 279
 280     /* Create protocol tree */
 281     ti = proto_tree_add_item(tree, proto_pcomascii, tvb, offset, -1, ENC_NA);
 282     pcomascii_tree = proto_item_add_subtree(ti, ett_pcomascii);
 283
 284     if (value_is_in_range(global_pcomtcp_tcp_ports, pinfo->srcport)) { // Reply
 285         proto_tree_add_item(pcomascii_tree, hf_pcomascii_stx, tvb,
 286                 offset, 2, ENC_ASCII); // "/A"
 287         offset += 2;
 288     }else{
 289         proto_tree_add_item(pcomascii_tree, hf_pcomascii_stx, tvb,
 290                 offset, 1, ENC_ASCII); // "/"
 291         offset += 1;
 292     }
 293
 294     proto_tree_add_item(pcomascii_tree, hf_pcomascii_unitid, tvb,
 295             offset, 2, ENC_ASCII|ENC_NA);
 296     offset += 2;
 297
 298     // CCs can be 2 or 3 hex chars
 299     cc = tvb_get_ntoh24(tvb, offset);
 300     cc_str = try_val_to_str(cc, pcomascii_cc_vals);
 301     if ( cc_str != NULL && !value_is_in_range(global_pcomtcp_tcp_ports, pinfo->srcport)) {
 302         cc_len = 3;
 303     }else {
 304         cc = tvb_get_ntohs(tvb, offset);
 305         cc_str = try_val_to_str(cc, pcomascii_cc_vals);
 306         if (cc_str != NULL ){
 307             cc_len = 2;
 308         }else{
 309             cc_len = 0;
 310         }
 311     }
 312     if ( cc_len > 0 ){
 313         cc_str2 = tvb_get_string_enc(pinfo->pool, tvb, offset, cc_len, ENC_ASCII);
 314         proto_tree_add_string_format_value(pcomascii_tree,
 315                 hf_pcomascii_command_code, tvb, offset, cc_len,
 316                 cc_str2, "%s (%s)", cc_str, cc_str2);
 317         offset += cc_len;
 318         switch(cc)
 319         {
 320             case PCOMASCII_READ_INPUTS:
 321             case PCOMASCII_READ_OUTPUTS:
 322             case PCOMASCII_READ_SYSTEM_BITS:
 323             case PCOMASCII_READ_MEMORY_BITS:
 324                op_type = 1; // read operation
 325                op_size = 1; // 1 char per operand
 326                break;
 327             case PCOMASCII_READ_SYSTEM_INTEGERS:
 328             case PCOMASCII_READ_MEMORY_INTEGERS:
 329                op_type = 1; // read operation
 330                op_size = 4; // 4 chars per operand
 331                break;
 332             case PCOMASCII_READ_SYSTEM_LONGS:
 333             case PCOMASCII_READ_MEMORY_LONGS:
 334             case PCOMASCII_READ_SYSTEM_DOUBLE_WORDS:
 335             case PCOMASCII_READ_MEMORY_DOUBLE_WORDS:
 336             case PCOMASCII_READ_LONGS:
 337                op_type = 1; // read operation
 338                op_size = 8; // 8 chars per operand
 339                break;
 340             case PCOMASCII_WRITE_OUTPUTS:
 341             case PCOMASCII_WRITE_SYSTEM_BITS:
 342             case PCOMASCII_WRITE_MEMORY_BITS:
 343                op_type = 2; // write operation
 344                op_size = 1; // 1 char per operand
 345                break;
 346             case PCOMASCII_WRITE_SYSTEM_INTEGERS:
 347             case PCOMASCII_WRITE_MEMORY_INTEGERS:
 348                op_type = 2; // write operation
 349                op_size = 4; // 4 chars per operand
 350                break;
 351             case PCOMASCII_WRITE_MEMORY_LONGS:
 352             case PCOMASCII_WRITE_SYSTEM_LONGS:
 353             case PCOMASCII_WRITE_SYSTEM_DOUBLE_WORDS:
 354             case PCOMASCII_WRITE_MEMORY_DOUBLE_WORDS:
 355             case PCOMASCII_WRITE_LONGS:
 356                op_type = 2; // write operation
 357                op_size = 8; // 8 chars per operand
 358                break;
 359             default:
 360                op_type = 0;
 361                op_size = 0;
 362                break;
 363         }
 364         if (value_is_in_range(global_pcomtcp_tcp_ports, pinfo->destport)) { // Request
 365             if(op_type == 1 || op_type == 2) { // read & write op
 366                 proto_tree_add_item(pcomascii_tree, hf_pcomascii_address,
 367                                 tvb, offset, 4, ENC_ASCII);
 368                 offset += 4;
 369                 proto_tree_add_item(pcomascii_tree, hf_pcomascii_length,
 370                             tvb, offset, 2, ENC_ASCII);
 371                 offset += 2;
 372             }
 373             if(op_type == 2) { // write only
 374                 nvalues = (tvb_reported_length(tvb)-3-offset) / op_size;
 375                 for (i = 0; i < nvalues; i++) {
 376                     proto_tree_add_item(pcomascii_tree, hf_pcomascii_address_value,
 377                              tvb, offset, op_size , ENC_ASCII);
 378                     offset += op_size;
 379                 }
 380             }
 381         } else { // reply
 382              if(op_type == 1) { // read only
 383                 nvalues = (tvb_reported_length(tvb)-offset-3) / op_size;
 384                 for (i = 0; i < nvalues; i++) {
 385                     proto_tree_add_item(pcomascii_tree, hf_pcomascii_address_value,
 386                              tvb, offset, op_size , ENC_ASCII);
 387                     offset += op_size;
 388                 }
 389             }
 390         }
 391
 392     }
 393
 394     if (tvb_reported_length(tvb)-offset-3 > 0){ // remaining (variable) bytes between CC and checksum
 395         hf_pcomascii_command_item = proto_tree_add_item(pcomascii_tree, hf_pcomascii_command, tvb,
 396                 offset, tvb_reported_length(tvb)-offset-3, ENC_ASCII);
 397         offset += (tvb_reported_length(tvb)-offset-3); //-3 from checksum and etx
 398         if(cc_len <= 0){
 399             expert_add_info_format(pinfo, hf_pcomascii_command_item,
 400                     &ei_pcomascii_command_unsupported, "Unsupported Command");
 401         }
 402     }
 403
 404     proto_tree_add_item(pcomascii_tree, hf_pcomascii_checksum, tvb,
 405             offset, 2, ENC_LITTLE_ENDIAN);
 406     offset += 2;
 407     proto_tree_add_item(pcomascii_tree, hf_pcomascii_etx, tvb,
 408             offset, 1, ENC_ASCII);
 409
 410     return tvb_reported_length(tvb);
 411 }
 412
 413 static int
 414 dissect_pcombinary(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
 415         void *data _U_)
 416 {
 417     /* Set up structures needed to add the protocol subtree and manage it */
 418     proto_item  *ti;
 419     proto_tree  *pcombinary_tree;
 420
 421     unsigned     offset = 0;
 422     proto_item    *hf_pcombinary_reserved1_item = NULL;
 423     proto_item    *hf_pcombinary_reserved2_item = NULL;
 424     proto_item    *hf_pcombinary_reserved3_item = NULL;
 425     proto_item    *hf_pcombinary_reserved4_item = NULL;
 426     proto_item    *hf_pcombinary_command_item = NULL;
 427
 428     uint8_t command;
 429     const char* command_str;
 430
 431     /* Create protocol tree */
 432     ti = proto_tree_add_item(tree, proto_pcombinary, tvb, offset, -1, ENC_NA);
 433     pcombinary_tree = proto_item_add_subtree(ti, ett_pcombinary);
 434
 435     proto_tree_add_item(pcombinary_tree, hf_pcombinary_stx, tvb,
 436             offset, 6, ENC_ASCII);
 437
 438     offset += 6;
 439     if (value_is_in_range(global_pcomtcp_tcp_ports, pinfo->srcport)) { // these bytes are transposed
 440         hf_pcombinary_reserved1_item = proto_tree_add_item(pcombinary_tree,
 441                 hf_pcombinary_reserved1, tvb, offset, 1, ENC_NA);
 442         if(tvb_get_uint8(tvb, offset) !=254){
 443             expert_add_info_format(pinfo, hf_pcombinary_reserved1_item,
 444                     &ei_pcombinary_reserved1_bad_value,"Isn't 0xfe");
 445         }
 446         offset += 1;
 447         proto_tree_add_item(pcombinary_tree, hf_pcombinary_id, tvb,
 448                 offset, 1, ENC_NA);
 449         offset += 1;
 450     }else{
 451         proto_tree_add_item(pcombinary_tree, hf_pcombinary_id, tvb,
 452                 offset, 1, ENC_NA);
 453         offset += 1;
 454         proto_tree_add_item(pcombinary_tree, hf_pcombinary_reserved1, tvb,
 455                 offset, 1, ENC_NA);
 456         offset += 1;
 457     }
 458     hf_pcombinary_reserved2_item = proto_tree_add_item(pcombinary_tree,
 459             hf_pcombinary_reserved2, tvb, offset, 1, ENC_NA);
 460     if( tvb_get_uint8(tvb, offset) !=1)
 461         expert_add_info_format(pinfo, hf_pcombinary_reserved2_item,
 462                 &ei_pcombinary_reserved2_bad_value,"Isn't 1");
 463     offset += 1;
 464     hf_pcombinary_reserved3_item = proto_tree_add_item(pcombinary_tree,
 465             hf_pcombinary_reserved3, tvb, offset, 3, ENC_LITTLE_ENDIAN);
 466     if( tvb_get_letoh24(tvb,offset) != 0)
 467         expert_add_info_format(pinfo, hf_pcombinary_reserved3_item,
 468                 &ei_pcombinary_reserved3_bad_value,"Isn't 0");
 469     offset += 3;
 470
 471     command = tvb_get_uint8(tvb, offset);
 472     if (value_is_in_range(global_pcomtcp_tcp_ports, pinfo->srcport)) { // reply
 473         command_str = try_val_to_str(command, pcombinary_command_vals_reply);
 474     }else{
 475         command_str = try_val_to_str(command, pcombinary_command_vals_request);
 476     }
 477     if ( command_str != NULL ) {
 478         proto_tree_add_uint_format_value(pcombinary_tree,
 479             hf_pcombinary_command, tvb, offset, 1,
 480                 command, "%s (%02x)", command_str, command);
 481     }else{
 482         hf_pcombinary_command_item = proto_tree_add_item(pcombinary_tree, hf_pcombinary_command, tvb,
 483                 offset, 1, ENC_NA);
 484         expert_add_info_format(pinfo, hf_pcombinary_command_item,
 485                 &ei_pcombinary_command_unsupported,"Unsupported Command");}
 486     offset += 1;
 487
 488     hf_pcombinary_reserved4_item = proto_tree_add_item(pcombinary_tree,
 489             hf_pcombinary_reserved4, tvb, offset, 1, ENC_NA);
 490     if( tvb_get_uint8(tvb, offset) !=0)
 491         expert_add_info_format(pinfo, hf_pcombinary_reserved4_item,
 492                 &ei_pcombinary_reserved4_bad_value,"Isn't 0");
 493     offset += 1;
 494     proto_tree_add_item(pcombinary_tree, hf_pcombinary_command_specific, tvb,
 495             offset, 6, ENC_NA);
 496     offset += 6;
 497     proto_tree_add_item(pcombinary_tree, hf_pcombinary_data_length, tvb,
 498             offset, 2, ENC_LITTLE_ENDIAN);
 499     offset += 2;
 500     proto_tree_add_item(pcombinary_tree, hf_pcombinary_header_checksum, tvb,
 501             offset, 2, ENC_NA);
 502     offset += 2;
 503     if ((tvb_reported_length(tvb) - 27) > 0) // ( -3 footer - 24 header)
 504         proto_tree_add_item(pcombinary_tree, hf_pcombinary_data, tvb,
 505                 offset, tvb_reported_length(tvb)-27, ENC_NA);
 506     offset += (tvb_reported_length(tvb)-27);
 507     proto_tree_add_item(pcombinary_tree, hf_pcombinary_footer_checksum, tvb,
 508             offset, 2, ENC_LITTLE_ENDIAN);
 509     offset += 2;
 510     proto_tree_add_item(pcombinary_tree, hf_pcombinary_etx, tvb,
 511             offset, 1, ENC_ASCII);
 512
 513     return tvb_reported_length(tvb);
 514 }
 515
 516 static void
 517 apply_pcomtcp_prefs(void)
 518 {
 519     global_pcomtcp_tcp_ports = prefs_get_range_value("pcomtcp", "tcp.port");
 520 }
 521
 522 void
 523 proto_register_pcomtcp(void)
 524 {
 525     static hf_register_info hf_pcomtcp[] = {
 526         { &hf_pcomtcp_transid,
 527             { "Transaction Identifier", "pcomtcp.trans_id",
 528                 FT_UINT16, BASE_DEC, NULL, 0x0,
 529                 NULL, HFILL }
 530         },
 531         { &hf_pcomtcp_protocol,
 532             { "Protocol Mode", "pcomtcp.protocol",
 533                 FT_UINT8, BASE_DEC, VALS(pcomp_protocol_vals), 0x0,
 534                 NULL, HFILL }
 535         },
 536         { &hf_pcomtcp_reserved,
 537             { "Reserved", "pcomtcp.reserved",
 538                 FT_UINT8, BASE_DEC, NULL, 0x0,
 539                 NULL, HFILL }
 540         },
 541         { &hf_pcomtcp_length,
 542             { "Length (bytes)", "pcomtcp.length",
 543                 FT_UINT16, BASE_DEC, NULL, 0x0,
 544                 NULL, HFILL }
 545         },
 546     };
 547
 548
 549     static hf_register_info hf_pcomascii[] = {
 550         { &hf_pcomascii_stx,
 551             { "STX", "pcomascii.stx",
 552                 FT_STRING, BASE_NONE, NULL, 0x0,
 553                 NULL, HFILL }
 554         },
 555         { &hf_pcomascii_unitid,
 556             { "Unit Identifier", "pcomascii.unitid",
 557                 FT_UINT16, BASE_HEX, NULL, 0x0,
 558                 NULL, HFILL }
 559         },
 560         { &hf_pcomascii_command_code,
 561             { "Command Code", "pcomascii.command_code",
 562                 FT_STRING, BASE_NONE, NULL, 0x0,
 563                 NULL, HFILL }
 564         },
 565         { &hf_pcomascii_address,
 566             { "Address", "pcomascii.address",
 567                 FT_STRING, BASE_NONE, NULL, 0x0,
 568                 NULL, HFILL }
 569         },
 570         { &hf_pcomascii_length,
 571             { "Length", "pcomascii.length",
 572                 FT_STRING, BASE_NONE, NULL, 0x0,
 573                 NULL, HFILL }
 574         },
 575         { &hf_pcomascii_address_value,
 576             { "Address Value", "pcomascii.address_value",
 577                 FT_STRING, BASE_NONE, NULL, 0x0,
 578                 NULL, HFILL }
 579         },
 580         { &hf_pcomascii_command,
 581             { "Command", "pcomascii.command",
 582                 FT_STRING, BASE_NONE, NULL, 0x0,
 583                 NULL, HFILL }
 584         },
 585         { &hf_pcomascii_checksum,
 586             { "Checksum", "pcomascii.checksum",
 587                 FT_UINT16, BASE_HEX, NULL, 0x0,
 588                 NULL, HFILL }
 589         },
 590         { &hf_pcomascii_etx,
 591             { "ETX", "pcomascii.etx",
 592                 FT_STRING, BASE_NONE, NULL, 0x0,
 593                 NULL, HFILL }
 594         },
 595     };
 596
 597
 598     static hf_register_info hf_pcombinary[] = {
 599         { &hf_pcombinary_stx,
 600             { "STX", "pcombinary.stx",
 601                 FT_STRING, BASE_NONE, NULL, 0x0,
 602                 NULL, HFILL }
 603         },
 604         { &hf_pcombinary_id,
 605             { "ID (CANBUS or RS485)", "pcombinary.id",
 606                 FT_UINT8, BASE_DEC, NULL, 0x0,
 607                 NULL, HFILL }
 608         },
 609         { &hf_pcombinary_reserved1,
 610             { "Reserved", "pcombinary.reserved1",
 611                 FT_UINT8, BASE_HEX, NULL, 0x0,
 612                 NULL, HFILL }
 613         },
 614         { &hf_pcombinary_reserved2,
 615             { "Reserved", "pcombinary.reserved2",
 616                 FT_UINT8, BASE_HEX, NULL, 0x0,
 617                 NULL, HFILL }
 618         },
 619         { &hf_pcombinary_reserved3,
 620             { "Reserved", "pcombinary.reserved3",
 621                 FT_UINT24, BASE_HEX, NULL, 0x0,
 622                 NULL, HFILL }
 623         },
 624         { &hf_pcombinary_command,
 625             { "Command", "pcombinary.command",
 626                 FT_UINT8, BASE_HEX, NULL, 0x0,
 627                 NULL, HFILL }
 628         },
 629         { &hf_pcombinary_reserved4,
 630             { "Reserved", "pcombinary.reserved0",
 631                 FT_UINT8, BASE_HEX, NULL, 0x0,
 632                 NULL, HFILL }
 633         },
 634         { &hf_pcombinary_command_specific,
 635             { "Command Details", "pcombinary.command_specific",
 636                 FT_BYTES, BASE_NONE, NULL, 0x0,
 637                 NULL, HFILL }
 638         },
 639         { &hf_pcombinary_data_length,
 640             { "Data Length", "pcombinary.data_length",
 641                 FT_UINT16, BASE_DEC, NULL, 0x0,
 642                 NULL, HFILL }
 643         },
 644         { &hf_pcombinary_header_checksum,
 645             { "(Header) Checksum", "pcombinary.header_checksum",
 646                 FT_UINT16, BASE_HEX, NULL, 0x0,
 647                 NULL, HFILL }
 648         },
 649         { &hf_pcombinary_data,
 650             { "Data", "pcombinary.data",
 651                 FT_BYTES, BASE_NONE, NULL, 0x0,
 652                 NULL, HFILL }
 653         },
 654         { &hf_pcombinary_footer_checksum,
 655             { "(Footer) Checksum", "pcombinary.footer_checksum",
 656                 FT_UINT16, BASE_HEX, NULL, 0x0,
 657                 NULL, HFILL }
 658         },
 659         { &hf_pcombinary_etx,
 660             { "ETX", "pcombinary.etx",
 661                 FT_STRING, BASE_NONE, NULL, 0x0,
 662                 NULL, HFILL }
 663         },
 664     };
 665
 666     /* Setup protocol subtree array */
 667     static int *ett[] = {
 668         &ett_pcomtcp,
 669         &ett_pcomascii,
 670         &ett_pcombinary
 671     };
 672
 673     static ei_register_info pcomtcp_ei[] = {
 674         { &ei_pcomtcp_reserved_bad_value,
 675           { "pcombinary.reserved.bad_value", PI_PROTOCOL, PI_WARN,
 676             "Isn't 0", EXPFILL }
 677         },
 678     };
 679
 680     static ei_register_info pcombinary_ei[] = {
 681         { &ei_pcombinary_reserved1_bad_value,
 682           { "pcombinary.reserved1.bad_value", PI_PROTOCOL, PI_WARN,
 683             "Isn't  0xfe", EXPFILL }
 684         },
 685         { &ei_pcombinary_reserved2_bad_value,
 686           { "pcombinary.reserved2.bad_value", PI_PROTOCOL, PI_WARN,
 687             "Isn't  1", EXPFILL }
 688         },
 689         { &ei_pcombinary_reserved3_bad_value,
 690           { "pcombinary.reserved3.bad_value", PI_PROTOCOL, PI_WARN,
 691             "Isn't  0", EXPFILL }
 692         },
 693         { &ei_pcombinary_reserved4_bad_value,
 694           { "pcombinary.reserved4.bad_value", PI_PROTOCOL, PI_WARN,
 695             "Isn't  0", EXPFILL }
 696         },
 697         { &ei_pcombinary_command_unsupported,
 698           { "pcombinary.command.unsupported", PI_PROTOCOL, PI_WARN,
 699             "Unsupported Command", EXPFILL }
 700         },
 701     };
 702     static ei_register_info pcomascii_ei[] = {
 703         { &ei_pcomascii_command_unsupported,
 704           { "pcomascii.command.unsupported", PI_PROTOCOL, PI_WARN,
 705             "Unsupported Command", EXPFILL }
 706         },
 707     };
 708
 709     expert_module_t* expert_pcomtcp;
 710     expert_module_t* expert_pcomascii;
 711     expert_module_t* expert_pcombinary;
 712
 713     /* Register the protocol name and description */
 714     proto_pcomtcp = proto_register_protocol("PCOM/TCP","PCOM/TCP", "pcomtcp");
 715     proto_pcomascii = proto_register_protocol("PCOM ASCII","PCOM ASCII", "pcomascii");
 716     proto_pcombinary = proto_register_protocol("PCOM BINARY","PCOM BINARY", "pcombinary");
 717
 718     pcomtcp_handle = register_dissector("pcomtcp", dissect_pcomtcp, proto_pcomtcp);
 719     pcomascii_handle = register_dissector("pcomascii", dissect_pcomascii, proto_pcomascii);
 720     pcombinary_handle = register_dissector("pcombinary", dissect_pcombinary, proto_pcombinary);
 721
 722     /* Required function calls to register the header fields and subtrees */
 723     proto_register_field_array(proto_pcomtcp, hf_pcomtcp, array_length(hf_pcomtcp));
 724     proto_register_field_array(proto_pcomascii, hf_pcomascii, array_length(hf_pcomascii));
 725     proto_register_field_array(proto_pcombinary, hf_pcombinary, array_length(hf_pcombinary));
 726
 727     proto_register_subtree_array(ett, array_length(ett));
 728     expert_pcomtcp = expert_register_protocol(proto_pcomtcp);
 729     expert_pcomascii = expert_register_protocol(proto_pcomascii);
 730     expert_pcombinary = expert_register_protocol(proto_pcombinary);
 731
 732     expert_register_field_array(expert_pcomtcp, pcomtcp_ei, array_length(pcomtcp_ei));
 733     expert_register_field_array(expert_pcomascii, pcomascii_ei, array_length(pcomascii_ei));
 734     expert_register_field_array(expert_pcombinary, pcombinary_ei, array_length(pcombinary_ei));
 735
 736     prefs_register_protocol(proto_pcomtcp, apply_pcomtcp_prefs);
 737
 738 }
 739
 740 void
 741 proto_reg_handoff_pcomtcp(void)
 742 {
 743     dissector_add_uint_with_preference("tcp.port", PCOMTCP_TCP_PORT, pcomtcp_handle);
 744     apply_pcomtcp_prefs();
 745 }
 746
 747 /*
 748  * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
 749  *
 750  * Local variables:
 751  * c-basic-offset: 4
 752  * tab-width: 8
 753  * indent-tabs-mode: nil
 754  * End:
 755  *
 756  * vi: set shiftwidth=4 tabstop=8 expandtab:
 757  * :indentSize=4:tabSize=8:noTabs=true:
 758  */