epan/dissectors/packet-mrp-mvrp.c

   1 /* packet-mrp_mvrp.c
   2  * Routines for MVRP (MRP Multiple VLAN Registration Protocol) dissection
   3  * Copyright 2011, Pascal Levesque <plevesque[AT]orthogone.ca>
   4  *
   5  *
   6  * Based on the code from packet-mrp-mmrp.c (MMRP) from
   7  * Johannes Jochen <johannes.jochen[AT]belden.com>
   8  * Copyright 2011
   9  *
  10  * Wireshark - Network traffic analyzer
  11  * By Gerald Combs <gerald[AT]wireshark.org>
  12  * Copyright 1998 Gerald Combs
  13  *
  14  * SPDX-License-Identifier: GPL-2.0-or-later
  15  *
  16  * The MVRP Protocol specification can be found at the following:
  17  * http://standards.ieee.org/about/get/802/802.1.html
  18  *
  19  */
  20
  21 #include "config.h"
  22
  23 #include <epan/packet.h>
  24 #include <epan/etypes.h>
  25
  26 void proto_register_mrp_mvrp(void);
  27 void proto_reg_handoff_mrp_mvrp(void);
  28
  29 static dissector_handle_t mvrp_handle;
  30
  31 /* MVRP End Mark Sequence */
  32 #define MVRP_END_MARK       0x0000
  33
  34 /**********************************************************/
  35 /* Offsets of fields within an MVRP packet                */
  36 /**********************************************************/
  37 #define MVRP_PROTOCOL_VERSION_OFFSET        0
  38
  39 /* Next comes the MVRP Message group */
  40 #define MVRP_MESSAGE_GROUP_OFFSET          (MVRP_PROTOCOL_VERSION_OFFSET + 1) /* Message is a group of fields */
  41 #define MVRP_ATTRIBUTE_TYPE_OFFSET         (MVRP_MESSAGE_GROUP_OFFSET)
  42 #define MVRP_ATTRIBUTE_LENGTH_OFFSET       (MVRP_ATTRIBUTE_TYPE_OFFSET + 1)
  43
  44 /* Next comes the MVRP AttributeList group */
  45 #define MVRP_ATTRIBUTE_LIST_GROUP_OFFSET   (MVRP_ATTRIBUTE_LENGTH_OFFSET + 1) /* AttributeList is a group of fields */
  46
  47 /* Next comes the MVRP VectorAttribute group */
  48 #define MVRP_VECTOR_ATTRIBUTE_GROUP_OFFSET (MVRP_ATTRIBUTE_LIST_GROUP_OFFSET) /* VectorAttribute is a group of fields */
  49 #define MVRP_VECTOR_HEADER_OFFSET          (MVRP_VECTOR_ATTRIBUTE_GROUP_OFFSET) /* contains the following two fields */
  50 #define MVRP_LEAVE_ALL_EVENT_OFFSET        (MVRP_VECTOR_HEADER_OFFSET)
  51 #define MVRP_LEAVE_ALL_EVENT_MASK           0xE000
  52 #define MVRP_NUMBER_OF_VALUES_OFFSET       (MVRP_VECTOR_HEADER_OFFSET)
  53 #define MVRP_NUMBER_OF_VALUES_MASK          0x1fff
  54
  55 /* Next comes the MVRP FirstValue group */
  56 #define MVRP_FIRST_VALUE_GROUP_OFFSET      (MVRP_VECTOR_HEADER_OFFSET + 2) /* FirstValue is a group of fields */
  57
  58 #define MVRP_VID_THREE_PACKED_OFFSET       (MVRP_FIRST_VALUE_GROUP_OFFSET + 2)
  59
  60 /**********************************************************/
  61 /* Valid field contents                                   */
  62 /**********************************************************/
  63
  64 /* Attribute Type definitions */
  65 #define MVRP_ATTRIBUTE_TYPE_VID       0x01
  66 static const value_string attribute_type_vals[] = {
  67     { MVRP_ATTRIBUTE_TYPE_VID, "VLAN Identifier" },
  68     { 0,                                    NULL }
  69 };
  70
  71 /* Leave All Event definitions */
  72 #define MVRP_NULLLEAVEALL   0
  73 #define MVRP_LEAVEALL       1
  74 static const value_string leave_all_vals[] = {
  75     { MVRP_NULLLEAVEALL, "Null" },
  76     { MVRP_LEAVEALL,     "Leave All" },
  77     { 0,                 NULL }
  78 };
  79
  80 /* Three Packed Event definitions */
  81 static const value_string three_packed_vals[] = {
  82     { 0, "New" },
  83     { 1, "JoinIn" },
  84     { 2, "In" },
  85     { 3, "JoinMt" },
  86     { 4, "Mt" },
  87     { 5, "Lv" },
  88     { 0, NULL }
  89 };
  90
  91 /**********************************************************/
  92 /* Initialize the protocol and registered fields          */
  93 /**********************************************************/
  94 static int proto_mvrp;
  95 static int hf_mvrp_proto_id;
  96 static int hf_mvrp_message; /* Message is a group of fields */
  97 static int hf_mvrp_attribute_type;
  98 static int hf_mvrp_attribute_length;
  99 static int hf_mvrp_attribute_list; /* AttributeList is a group of fields */
 100 static int hf_mvrp_vector_attribute; /* VectorAttribute is a group of fields */
 101
 102 /* The following VectorHeader contains the LeaveAllEvent and NumberOfValues */
 103 static int hf_mvrp_vector_header;
 104 static int hf_mvrp_leave_all_event;
 105 static int hf_mvrp_number_of_values;
 106 static int ett_vector_header;
 107 static int * const vector_header_fields[] = {
 108     &hf_mvrp_leave_all_event,
 109     &hf_mvrp_number_of_values,
 110     NULL
 111 };
 112
 113 static int hf_mvrp_first_value; /* FirstValue is a group of fields */
 114 static int hf_mvrp_vid;
 115 static int hf_mvrp_three_packed_event;
 116
 117 static int hf_mvrp_end_mark;
 118
 119 /* Initialize the subtree pointers */
 120 static int ett_mvrp;
 121 static int ett_msg;
 122 static int ett_attr_list;
 123 static int ett_vect_attr;
 124 static int ett_first_value;
 125
 126
 127
 128 /**********************************************************/
 129 /* Dissector starts here                                  */
 130 /**********************************************************/
 131
 132 /* dissect_mvrp_common1 (called from dissect_mvrp)
 133  *
 134  * dissect the following fields which are common to all MVRP attributes:
 135  *   Attribute Type
 136  *   Attribute Length
 137  *   Attribute List Length
 138  */
 139 static void
 140 dissect_mvrp_common1(proto_tree *msg_tree, tvbuff_t *tvb, int msg_offset)
 141 {
 142     proto_tree_add_item(msg_tree, hf_mvrp_attribute_type, tvb,
 143                         MVRP_ATTRIBUTE_TYPE_OFFSET + msg_offset, 1, ENC_BIG_ENDIAN);
 144     proto_tree_add_item(msg_tree, hf_mvrp_attribute_length, tvb,
 145                         MVRP_ATTRIBUTE_LENGTH_OFFSET + msg_offset, 1, ENC_BIG_ENDIAN);
 146 }
 147
 148
 149 /* dissect_mvrp_common2 (called from dissect_mvrp)
 150  *
 151  * dissect the following fields which are common to all MVRP attributes:
 152  *   Leave All Event
 153  *   Number of Values fields
 154  */
 155 static void
 156 dissect_mvrp_common2(proto_tree *vect_attr_tree, tvbuff_t *tvb, int msg_offset)
 157 {
 158     proto_tree_add_bitmask(vect_attr_tree, tvb, MVRP_VECTOR_HEADER_OFFSET + msg_offset,
 159                            hf_mvrp_vector_header, ett_vector_header, vector_header_fields, ENC_BIG_ENDIAN);
 160 }
 161
 162 /* dissect_mvrp_three_packed_event (called from dissect_mvrp)
 163  *
 164  * dissect one or more ThreePackedEvents
 165  */
 166 static unsigned
 167 dissect_mvrp_three_packed_event(proto_tree *vect_attr_tree, tvbuff_t *tvb, unsigned offset, uint16_t number_of_values)
 168 {
 169     unsigned counter;
 170
 171     for ( counter = 0; counter < number_of_values; ) {
 172         uint8_t value;
 173         uint8_t three_packed_event[3];
 174
 175         value = tvb_get_uint8(tvb, offset);
 176         three_packed_event[0] = value / 36;
 177         value -= 36 * three_packed_event[0];
 178         three_packed_event[1] = value / 6;
 179         value -=  6 * three_packed_event[1];
 180         three_packed_event[2] = value;
 181
 182         proto_tree_add_uint(vect_attr_tree, hf_mvrp_three_packed_event, tvb, offset, sizeof(uint8_t),
 183                             three_packed_event[0]);
 184         counter++;
 185         if ( counter < number_of_values ) {
 186             proto_tree_add_uint(vect_attr_tree, hf_mvrp_three_packed_event, tvb, offset, sizeof(uint8_t),
 187                                 three_packed_event[1]);
 188             counter++;
 189         }
 190         if ( counter < number_of_values ) {
 191             proto_tree_add_uint(vect_attr_tree, hf_mvrp_three_packed_event, tvb, offset, sizeof(uint8_t),
 192                                 three_packed_event[2]);
 193             counter++;
 194         }
 195
 196         offset++;
 197     }
 198     return offset;
 199 }
 200
 201 /* dissect_main
 202  *
 203  * main dissect function that calls the other functions listed above as necessary
 204  */
 205 static int
 206 dissect_mvrp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
 207 {
 208     /* Set up structures needed to add the protocol subtrees and manage them */
 209     proto_item *ti, *msg_ti, *attr_list_ti, *vect_attr_ti, *first_value_ti;
 210     proto_tree *mvrp_tree, *msg_tree, *attr_list_tree, *vect_attr_tree, *first_value_tree;
 211
 212     /* Make entries in Protocol column and Info column on summary display */
 213     col_set_str(pinfo->cinfo, COL_PROTOCOL, "MRP-MVRP");
 214
 215     col_set_str(pinfo->cinfo, COL_INFO, "Multiple VLAN Registration Protocol");
 216
 217     if (tree) {
 218         uint8_t attribute_type;
 219         uint8_t attribute_length;
 220         uint16_t number_of_values;
 221         unsigned offset = 0;
 222         unsigned int vect_attr_len;
 223         unsigned int msg_offset;  /* Use when handling multiple messages.  This points to current msg being decoded. */
 224         unsigned int vect_offset; /* Use when handling multiple vector attributes.  This points to the current vector attribute being decoded. */
 225
 226         ti = proto_tree_add_item(tree, proto_mvrp, tvb, 0, -1, ENC_NA);
 227         mvrp_tree = proto_item_add_subtree(ti, ett_mvrp);
 228
 229         proto_tree_add_item(mvrp_tree, hf_mvrp_proto_id, tvb, MVRP_PROTOCOL_VERSION_OFFSET, 1, ENC_BIG_ENDIAN);
 230
 231         /* MVRP supports multiple MRP Messages per frame.  Handle those Messages in
 232          * the following while() loop. You will know you are at the end of the list
 233          * of messages when the EndMark (0x0000) is encountered instead of an
 234          * Attribute Type and Attribute Length (guaranteed to not be 0x0000).
 235          */
 236         msg_offset = 0;
 237         while (MVRP_ATTRIBUTE_TYPE_OFFSET + msg_offset < tvb_reported_length(tvb) && tvb_get_ntohs(tvb, MVRP_ATTRIBUTE_TYPE_OFFSET + msg_offset) != MVRP_END_MARK) {
 238
 239             attribute_type = tvb_get_uint8(tvb, MVRP_ATTRIBUTE_TYPE_OFFSET + msg_offset);
 240             attribute_length = tvb_get_uint8(tvb, MVRP_ATTRIBUTE_LENGTH_OFFSET + msg_offset);
 241
 242             /* MVRP Message is a group of fields
 243              *
 244              * Contains AttributeType (1 byte)
 245              *        + AttributeLength (1 byte)
 246              *        + AttributeList (AttributeListLength bytes)
 247             *        bytes of data
 248             */
 249             msg_ti = proto_tree_add_item(mvrp_tree, hf_mvrp_message, tvb,
 250                                          MVRP_MESSAGE_GROUP_OFFSET + msg_offset,
 251                                          -1, ENC_NA);
 252             msg_tree = proto_item_add_subtree(msg_ti, ett_msg);
 253
 254             /* Append AttributeType description to the end of the "Message" heading */
 255             proto_item_append_text(msg_tree, ": %s (%d)",
 256                                    val_to_str_const(attribute_type, attribute_type_vals, "<Unknown>"),
 257                                    attribute_type);
 258
 259             dissect_mvrp_common1(msg_tree, tvb, msg_offset);
 260
 261             /* MVRP AttributeList is a group of fields
 262              *
 263              * Contains AttributeListLength bytes of data NOT
 264              */
 265             attr_list_ti = proto_tree_add_item(msg_tree, hf_mvrp_attribute_list, tvb,
 266                                                MVRP_ATTRIBUTE_LIST_GROUP_OFFSET + msg_offset,
 267                                                -1, ENC_NA);
 268             attr_list_tree = proto_item_add_subtree(attr_list_ti, ett_attr_list);
 269
 270
 271             /* MVRP supports multiple MRP Vector Attributes per Attribute List.  Handle those
 272              * Vector Attributes in the following while() loop. You will know you are at the
 273              * end of the list of Vector Attributes when the EndMark (0x0000) is encountered
 274              * instead of a Vector Header (guaranteed to not be 0x0000).
 275              */
 276             vect_offset = 0;
 277             while (MVRP_VECTOR_HEADER_OFFSET + msg_offset + vect_offset < tvb_reported_length(tvb) && tvb_get_ntohs(tvb, MVRP_VECTOR_HEADER_OFFSET + msg_offset + vect_offset) != MVRP_END_MARK) {
 278                 /* MVRP VectorAttribute is a group of fields
 279                  *
 280                  * Contains VectorHeader (2 bytes)
 281                  *        + FirstValue (AttributeLength bytes)
 282                  *        + VectorThreePacked (NumberOfValues @ 3/vector bytes)
 283                  *        + VectorFourPacked (NumberOfValues @ 4/vector bytes only for Listener attributes)
 284                  *        bytes of data
 285                  */
 286                 number_of_values = tvb_get_ntohs(tvb, MVRP_NUMBER_OF_VALUES_OFFSET + msg_offset + vect_offset)
 287                                    & MVRP_NUMBER_OF_VALUES_MASK;
 288
 289                 vect_attr_len = 2 + attribute_length + (number_of_values + 2)/3; /* stores 3 values per byte */
 290
 291                 vect_attr_ti = proto_tree_add_item(attr_list_tree, hf_mvrp_vector_attribute, tvb,
 292                                                    MVRP_VECTOR_ATTRIBUTE_GROUP_OFFSET + msg_offset + vect_offset,
 293                                                    vect_attr_len, ENC_NA);
 294
 295                 vect_attr_tree = proto_item_add_subtree(vect_attr_ti, ett_vect_attr);
 296
 297                 dissect_mvrp_common2(vect_attr_tree, tvb, msg_offset + vect_offset);
 298
 299                 if (attribute_type == MVRP_ATTRIBUTE_TYPE_VID) {
 300                     /* MVRP VLAN ID FirstValue is a group of fields
 301                      *
 302                      * Contains VID (2 bytes)
 303                      *        bytes of data
 304                      */
 305                     first_value_ti = proto_tree_add_item(vect_attr_tree, hf_mvrp_first_value, tvb,
 306                                                          MVRP_FIRST_VALUE_GROUP_OFFSET + msg_offset + vect_offset,
 307                                                          attribute_length, ENC_NA);
 308                     first_value_tree = proto_item_add_subtree(first_value_ti, ett_first_value);
 309
 310                     /* Add VLAN components to First Value tree */
 311                     proto_tree_add_item(first_value_tree, hf_mvrp_vid, tvb,
 312                                         MVRP_FIRST_VALUE_GROUP_OFFSET + msg_offset + vect_offset, 2, ENC_BIG_ENDIAN);
 313
 314                     /* Decode three packed events. */
 315                     offset = dissect_mvrp_three_packed_event(vect_attr_tree, tvb,
 316                                                              MVRP_VID_THREE_PACKED_OFFSET + msg_offset + vect_offset,
 317                                                              number_of_values);
 318
 319                 }
 320
 321                 vect_offset += vect_attr_len; /* Move to next Vector Attribute, if there is one */
 322             } /* Multiple VectorAttribute while() */
 323
 324             if (MVRP_VECTOR_HEADER_OFFSET + msg_offset + vect_offset < tvb_reported_length(tvb)) {
 325                 proto_tree_add_item(attr_list_tree, hf_mvrp_end_mark, tvb, offset, 2, ENC_BIG_ENDIAN); /* VectorAttribute EndMark */
 326             }
 327
 328             proto_item_set_len(attr_list_ti, vect_offset); /*without an endmark*/
 329             msg_offset += vect_offset + 4; /*  + endmark; Move to next Message, if there is one */
 330             proto_item_set_len(msg_ti, vect_offset + 2); /*length of message*/
 331
 332         } /* Multiple Message while() */
 333
 334         if (MVRP_ATTRIBUTE_TYPE_OFFSET + msg_offset < tvb_reported_length(tvb)) {
 335             proto_tree_add_item(mvrp_tree, hf_mvrp_end_mark, tvb, offset+2, 2, ENC_BIG_ENDIAN); /* Message EndMark */
 336         }
 337     }
 338     return tvb_captured_length(tvb);
 339 }
 340
 341
 342 /* Register the protocol with Wireshark */
 343 void
 344 proto_register_mrp_mvrp(void)
 345 {
 346     static hf_register_info hf[] = {
 347         { &hf_mvrp_proto_id,
 348             { "Protocol Version",      "mrp-mvrp.protocol_version",
 349               FT_UINT8,  BASE_DEC, NULL, 0x0, NULL, HFILL }
 350         },
 351         { &hf_mvrp_message, /* Message is a group of fields */
 352             { "Message",               "mrp-mvrp.message",
 353               FT_NONE,  BASE_NONE, NULL, 0x0, NULL, HFILL }
 354         },
 355         { &hf_mvrp_attribute_type,
 356             { "Attribute Type",        "mrp-mvrp.attribute_type",
 357               FT_UINT8,  BASE_DEC, VALS(attribute_type_vals), 0x0, NULL, HFILL }
 358         },
 359         { &hf_mvrp_attribute_length,
 360             { "Attribute Length",      "mrp-mvrp.attribute_length",
 361               FT_UINT8,  BASE_DEC, NULL, 0x0, NULL, HFILL }
 362         },
 363         { &hf_mvrp_attribute_list, /* AttributeList is a group of fields */
 364             { "Attribute List",        "mrp-mvrp.attribute_list",
 365               FT_NONE,  BASE_NONE, NULL, 0x0, NULL, HFILL }
 366         },
 367         { &hf_mvrp_vector_attribute, /* VectorAttribute is a group of fields */
 368             { "Vector Attribute",      "mrp-mvrp.vector_attribute",
 369               FT_NONE,  BASE_NONE, NULL, 0x0, NULL, HFILL }
 370         },
 371         { &hf_mvrp_vector_header,
 372             { "Vector Header",         "mrp-mvrp.vector_header",
 373               FT_UINT16, BASE_HEX, NULL, 0x0, NULL, HFILL }
 374         },
 375         { &hf_mvrp_leave_all_event,
 376             { "Leave All Event",       "mrp-mvrp.leave_all_event",
 377               FT_UINT16, BASE_DEC, VALS(leave_all_vals), MVRP_LEAVE_ALL_EVENT_MASK, NULL, HFILL }
 378         },
 379         { &hf_mvrp_number_of_values,
 380             { "Number of Values",      "mrp-mvrp.number_of_values",
 381               FT_UINT16, BASE_DEC, NULL, MVRP_NUMBER_OF_VALUES_MASK, NULL, HFILL }
 382         },
 383         { &hf_mvrp_first_value, /* FirstValue is a group of fields */
 384             { "First Value",           "mrp-mvrp.first_value",
 385               FT_NONE,  BASE_NONE, NULL, 0x0, NULL, HFILL }
 386         },
 387         { &hf_mvrp_vid,
 388             { "VLAN ID",               "mrp-mvrp.vid",
 389               FT_UINT16, BASE_DEC,  NULL, 0x0, NULL, HFILL }
 390         },
 391         { &hf_mvrp_three_packed_event,
 392             { "Attribute Event",       "mrp-mvrp.three_packed_event",
 393               FT_UINT8, BASE_DEC,  VALS(three_packed_vals), 0x0, NULL, HFILL }
 394         },
 395         { &hf_mvrp_end_mark,
 396             { "End Mark",              "mrp-mvrp.end_mark",
 397               FT_UINT16, BASE_HEX, NULL, 0x0, NULL, HFILL }
 398         },
 399     };
 400
 401     /* Setup protocol subtree array */
 402     static int *ett[] = {
 403         &ett_mvrp,
 404         &ett_msg,
 405         &ett_attr_list,
 406         &ett_vect_attr,
 407         &ett_vector_header,
 408         &ett_first_value
 409     };
 410
 411     /* Register the protocol name and description */
 412     proto_mvrp = proto_register_protocol("Multiple VLAN Registration Protocol",
 413                                          "MRP-MVRP", "mrp-mvrp");
 414
 415     /* Required function calls to register the header fields and subtrees used */
 416     proto_register_field_array(proto_mvrp, hf, array_length(hf));
 417     proto_register_subtree_array(ett, array_length(ett));
 418
 419     /* Register the dissector */
 420     mvrp_handle = register_dissector("mrp-mvrp", dissect_mvrp, proto_mvrp);
 421 }
 422
 423 void
 424 proto_reg_handoff_mrp_mvrp(void)
 425 {
 426     dissector_add_uint("ethertype", ETHERTYPE_MVRP, mvrp_handle);
 427 }
 428 /*
 429 * Editor modelines - https://www.wireshark.org/tools/modelines.html
 430 *
 431 * Local variables:
 432 * c-basic-offset: 4
 433 * tab-width: 8
 434 * indent-tabs-mode: nil
 435 * End:
 436 *
 437 * ex: set shiftwidth=4 tabstop=8 expandtab:
 438 * :indentSize=4:tabSize=8:noTabs=true:
 439 */