The Tcpdump Group git mirrors - tcpdump/blob - print-vtp.c

   1 /*
   2  * Copyright (c) 1998-2007 The TCPDUMP project
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that: (1) source code
   6  * distributions retain the above copyright notice and this paragraph
   7  * in its entirety, and (2) distributions including binary code include
   8  * the above copyright notice and this paragraph in its entirety in
   9  * the documentation or other materials provided with the distribution.
  10  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND
  11  * WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT
  12  * LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  13  * FOR A PARTICULAR PURPOSE.
  14  *
  15  * Reference documentation:
  16  *  http://www.cisco.com/en/US/tech/tk389/tk689/technologies_tech_note09186a0080094c52.shtml
  17  *  http://www.cisco.com/warp/public/473/21.html
  18  *  http://www.cisco.com/univercd/cc/td/doc/product/lan/trsrb/frames.htm
  19  *
  20  * Original code ode by Carles Kishimoto <carles.kishimoto@gmail.com>
  21  */
  22
  23 /* \summary: Cisco VLAN Trunking Protocol (VTP) printer */
  24
  25 #ifdef HAVE_CONFIG_H
  26 #include "config.h"
  27 #endif
  28
  29 #include <netdissect-stdinc.h>
  30
  31 #include "netdissect.h"
  32 #include "addrtoname.h"
  33 #include "extract.h"
  34
  35 #define VTP_HEADER_LEN                  36
  36 #define VTP_DOMAIN_NAME_LEN             32
  37 #define VTP_MD5_DIGEST_LEN              16
  38 #define VTP_UPDATE_TIMESTAMP_LEN        12
  39 #define VTP_VLAN_INFO_OFFSET            12
  40
  41 #define VTP_SUMMARY_ADV                 0x01
  42 #define VTP_SUBSET_ADV                  0x02
  43 #define VTP_ADV_REQUEST                 0x03
  44 #define VTP_JOIN_MESSAGE                0x04
  45
  46 struct vtp_vlan_ {
  47     uint8_t  len;
  48     uint8_t  status;
  49     uint8_t  type;
  50     uint8_t  name_len;
  51     uint16_t vlanid;
  52     uint16_t mtu;
  53     uint32_t index;
  54 };
  55
  56 static const struct tok vtp_message_type_values[] = {
  57     { VTP_SUMMARY_ADV, "Summary advertisement"},
  58     { VTP_SUBSET_ADV, "Subset advertisement"},
  59     { VTP_ADV_REQUEST, "Advertisement request"},
  60     { VTP_JOIN_MESSAGE, "Join message"},
  61     { 0, NULL }
  62 };
  63
  64 static const struct tok vtp_header_values[] = {
  65     { 0x01, "Followers"}, /* On Summary advertisement, 3rd byte is Followers */
  66     { 0x02, "Seq number"}, /* On Subset  advertisement, 3rd byte is Sequence number */
  67     { 0x03, "Rsvd"}, /* On Adver. requests 3rd byte is Rsvd */
  68     { 0x04, "Rsvd"}, /* On Adver. requests 3rd byte is Rsvd */
  69     { 0, NULL }
  70 };
  71
  72 static const struct tok vtp_vlan_type_values[] = {
  73     { 0x01, "Ethernet"},
  74     { 0x02, "FDDI"},
  75     { 0x03, "TrCRF"},
  76     { 0x04, "FDDI-net"},
  77     { 0x05, "TrBRF"},
  78     { 0, NULL }
  79 };
  80
  81 static const struct tok vtp_vlan_status[] = {
  82     { 0x00, "Operational"},
  83     { 0x01, "Suspended"},
  84     { 0, NULL }
  85 };
  86
  87 #define VTP_VLAN_SOURCE_ROUTING_RING_NUMBER      0x01
  88 #define VTP_VLAN_SOURCE_ROUTING_BRIDGE_NUMBER    0x02
  89 #define VTP_VLAN_STP_TYPE                        0x03
  90 #define VTP_VLAN_PARENT_VLAN                     0x04
  91 #define VTP_VLAN_TRANS_BRIDGED_VLAN              0x05
  92 #define VTP_VLAN_PRUNING                         0x06
  93 #define VTP_VLAN_BRIDGE_TYPE                     0x07
  94 #define VTP_VLAN_ARP_HOP_COUNT                   0x08
  95 #define VTP_VLAN_STE_HOP_COUNT                   0x09
  96 #define VTP_VLAN_BACKUP_CRF_MODE                 0x0A
  97
  98 static const struct tok vtp_vlan_tlv_values[] = {
  99     { VTP_VLAN_SOURCE_ROUTING_RING_NUMBER, "Source-Routing Ring Number TLV"},
 100     { VTP_VLAN_SOURCE_ROUTING_BRIDGE_NUMBER, "Source-Routing Bridge Number TLV"},
 101     { VTP_VLAN_STP_TYPE, "STP type TLV"},
 102     { VTP_VLAN_PARENT_VLAN, "Parent VLAN TLV"},
 103     { VTP_VLAN_TRANS_BRIDGED_VLAN, "Translationally bridged VLANs TLV"},
 104     { VTP_VLAN_PRUNING, "Pruning TLV"},
 105     { VTP_VLAN_BRIDGE_TYPE, "Bridge Type TLV"},
 106     { VTP_VLAN_ARP_HOP_COUNT, "Max ARP Hop Count TLV"},
 107     { VTP_VLAN_STE_HOP_COUNT, "Max STE Hop Count TLV"},
 108     { VTP_VLAN_BACKUP_CRF_MODE, "Backup CRF Mode TLV"},
 109     { 0,                                  NULL }
 110 };
 111
 112 static const struct tok vtp_stp_type_values[] = {
 113     { 1, "SRT"},
 114     { 2, "SRB"},
 115     { 3, "Auto"},
 116     { 0, NULL }
 117 };
 118
 119 void
 120 vtp_print (netdissect_options *ndo,
 121            const u_char *pptr, u_int length)
 122 {
 123     int type, len, tlv_len, tlv_value, mgmtd_len;
 124     const u_char *tptr;
 125     const struct vtp_vlan_ *vtp_vlan;
 126
 127     if (length < VTP_HEADER_LEN)
 128         goto trunc;
 129
 130     tptr = pptr;
 131
 132     ND_TCHECK2(*tptr, VTP_HEADER_LEN);
 133
 134     type = *(tptr+1);
 135     ND_PRINT((ndo, "VTPv%u, Message %s (0x%02x), length %u",
 136            *tptr,
 137            tok2str(vtp_message_type_values,"Unknown message type", type),
 138            type,
 139            length));
 140
 141     /* In non-verbose mode, just print version and message type */
 142     if (ndo->ndo_vflag < 1) {
 143         return;
 144     }
 145
 146     /* verbose mode print all fields */
 147     ND_PRINT((ndo, "\n\tDomain name: "));
 148     mgmtd_len = *(tptr + 3);
 149     if (mgmtd_len < 1 ||  mgmtd_len > 32) {
 150         ND_PRINT((ndo, " [invalid MgmtD Len %d]", mgmtd_len));
 151         return;
 152     }
 153     fn_printzp(ndo, tptr + 4, mgmtd_len, NULL);
 154     ND_PRINT((ndo, ", %s: %u",
 155            tok2str(vtp_header_values, "Unknown", type),
 156            *(tptr+2)));
 157
 158     tptr += VTP_HEADER_LEN;
 159
 160     switch (type) {
 161
 162     case VTP_SUMMARY_ADV:
 163
 164         /*
 165          *  SUMMARY ADVERTISEMENT
 166          *
 167          *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 168          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 169          *  |     Version   |     Code      |    Followers  |    MgmtD Len  |
 170          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 171          *  |       Management Domain Name  (zero-padded to 32 bytes)       |
 172          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 173          *  |                    Configuration revision number              |
 174          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 175          *  |                  Updater Identity IP address                  |
 176          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 177          *  |                    Update Timestamp (12 bytes)                |
 178          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 179          *  |                        MD5 digest (16 bytes)                  |
 180          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 181          *
 182          */
 183
 184         ND_TCHECK2(*tptr, 8);
 185         ND_PRINT((ndo, "\n\t  Config Rev %x, Updater %s",
 186                EXTRACT_32BITS(tptr),
 187                ipaddr_string(ndo, tptr+4)));
 188         tptr += 8;
 189         ND_TCHECK2(*tptr, VTP_UPDATE_TIMESTAMP_LEN);
 190         ND_PRINT((ndo, ", Timestamp 0x%08x 0x%08x 0x%08x",
 191                EXTRACT_32BITS(tptr),
 192                EXTRACT_32BITS(tptr + 4),
 193                EXTRACT_32BITS(tptr + 8)));
 194         tptr += VTP_UPDATE_TIMESTAMP_LEN;
 195         ND_TCHECK2(*tptr, VTP_MD5_DIGEST_LEN);
 196         ND_PRINT((ndo, ", MD5 digest: %08x%08x%08x%08x",
 197                EXTRACT_32BITS(tptr),
 198                EXTRACT_32BITS(tptr + 4),
 199                EXTRACT_32BITS(tptr + 8),
 200                EXTRACT_32BITS(tptr + 12)));
 201         tptr += VTP_MD5_DIGEST_LEN;
 202         break;
 203
 204     case VTP_SUBSET_ADV:
 205
 206         /*
 207          *  SUBSET ADVERTISEMENT
 208          *
 209          *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 210          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 211          *  |     Version   |     Code      |   Seq number  |    MgmtD Len  |
 212          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 213          *  |       Management Domain Name  (zero-padded to 32 bytes)       |
 214          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 215          *  |                    Configuration revision number              |
 216          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 217          *  |                         VLAN info field 1                     |
 218          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 219          *  |                         ................                      |
 220          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 221          *  |                         VLAN info field N                     |
 222          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 223          *
 224          */
 225
 226         ND_TCHECK_32BITS(tptr);
 227         ND_PRINT((ndo, ", Config Rev %x", EXTRACT_32BITS(tptr)));
 228
 229         /*
 230          *  VLAN INFORMATION
 231          *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 232          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 233          *  | V info len    |    Status     |  VLAN type    | VLAN name len |
 234          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 235          *  |       ISL vlan id             |            MTU size           |
 236          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 237          *  |                     802.10 index (SAID)                       |
 238          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 239          *  |                         VLAN name                             |
 240          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 241          *
 242          */
 243
 244         tptr += 4;
 245         while (tptr < (pptr+length)) {
 246
 247             ND_TCHECK_8BITS(tptr);
 248             len = *tptr;
 249             if (len == 0)
 250                 break;
 251
 252             ND_TCHECK2(*tptr, len);
 253
 254             vtp_vlan = (const struct vtp_vlan_*)tptr;
 255             ND_TCHECK(*vtp_vlan);
 256             ND_PRINT((ndo, "\n\tVLAN info status %s, type %s, VLAN-id %u, MTU %u, SAID 0x%08x, Name ",
 257                    tok2str(vtp_vlan_status,"Unknown",vtp_vlan->status),
 258                    tok2str(vtp_vlan_type_values,"Unknown",vtp_vlan->type),
 259                    EXTRACT_16BITS(&vtp_vlan->vlanid),
 260                    EXTRACT_16BITS(&vtp_vlan->mtu),
 261                    EXTRACT_32BITS(&vtp_vlan->index)));
 262             fn_printzp(ndo, tptr + VTP_VLAN_INFO_OFFSET, vtp_vlan->name_len, NULL);
 263
 264             /*
 265              * Vlan names are aligned to 32-bit boundaries.
 266              */
 267             len  -= VTP_VLAN_INFO_OFFSET + 4*((vtp_vlan->name_len + 3)/4);
 268             tptr += VTP_VLAN_INFO_OFFSET + 4*((vtp_vlan->name_len + 3)/4);
 269
 270             /* TLV information follows */
 271
 272             while (len > 0) {
 273
 274                 /*
 275                  * Cisco specs says 2 bytes for type + 2 bytes for length, take only 1
 276                  * See: http://www.cisco.com/univercd/cc/td/doc/product/lan/trsrb/frames.htm
 277                  */
 278                 type = *tptr;
 279                 tlv_len = *(tptr+1);
 280
 281                 ND_PRINT((ndo, "\n\t\t%s (0x%04x) TLV",
 282                        tok2str(vtp_vlan_tlv_values, "Unknown", type),
 283                        type));
 284
 285                 /*
 286                  * infinite loop check
 287                  */
 288                 if (type == 0 || tlv_len == 0) {
 289                     return;
 290                 }
 291
 292                 ND_TCHECK2(*tptr, tlv_len * 2 +2);
 293
 294                 tlv_value = EXTRACT_16BITS(tptr+2);
 295
 296                 switch (type) {
 297                 case VTP_VLAN_STE_HOP_COUNT:
 298                     ND_PRINT((ndo, ", %u", tlv_value));
 299                     break;
 300
 301                 case VTP_VLAN_PRUNING:
 302                     ND_PRINT((ndo, ", %s (%u)",
 303                            tlv_value == 1 ? "Enabled" : "Disabled",
 304                            tlv_value));
 305                     break;
 306
 307                 case VTP_VLAN_STP_TYPE:
 308                     ND_PRINT((ndo, ", %s (%u)",
 309                            tok2str(vtp_stp_type_values, "Unknown", tlv_value),
 310                            tlv_value));
 311                     break;
 312
 313                 case VTP_VLAN_BRIDGE_TYPE:
 314                     ND_PRINT((ndo, ", %s (%u)",
 315                            tlv_value == 1 ? "SRB" : "SRT",
 316                            tlv_value));
 317                     break;
 318
 319                 case VTP_VLAN_BACKUP_CRF_MODE:
 320                     ND_PRINT((ndo, ", %s (%u)",
 321                            tlv_value == 1 ? "Backup" : "Not backup",
 322                            tlv_value));
 323                     break;
 324
 325                     /*
 326                      * FIXME those are the defined TLVs that lack a decoder
 327                      * you are welcome to contribute code ;-)
 328                      */
 329
 330                 case VTP_VLAN_SOURCE_ROUTING_RING_NUMBER:
 331                 case VTP_VLAN_SOURCE_ROUTING_BRIDGE_NUMBER:
 332                 case VTP_VLAN_PARENT_VLAN:
 333                 case VTP_VLAN_TRANS_BRIDGED_VLAN:
 334                 case VTP_VLAN_ARP_HOP_COUNT:
 335                 default:
 336                     print_unknown_data(ndo, tptr, "\n\t\t  ", 2 + tlv_len*2);
 337                     break;
 338                 }
 339                 len -= 2 + tlv_len*2;
 340                 tptr += 2 + tlv_len*2;
 341             }
 342         }
 343         break;
 344
 345     case VTP_ADV_REQUEST:
 346
 347         /*
 348          *  ADVERTISEMENT REQUEST
 349          *
 350          *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 351          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 352          *  |     Version   |     Code      |   Reserved    |    MgmtD Len  |
 353          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 354          *  |       Management Domain Name  (zero-padded to 32 bytes)       |
 355          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 356          *  |                          Start value                          |
 357          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 358          *
 359          */
 360
 361         ND_TCHECK2(*tptr, 4);
 362         ND_PRINT((ndo, "\n\tStart value: %u", EXTRACT_32BITS(tptr)));
 363         break;
 364
 365     case VTP_JOIN_MESSAGE:
 366
 367         /* FIXME - Could not find message format */
 368         break;
 369
 370     default:
 371         break;
 372     }
 373
 374     return;
 375
 376  trunc:
 377     ND_PRINT((ndo, "[|vtp]"));
 378 }
 379
 380 /*
 381  * Local Variables:
 382  * c-style: whitesmith
 383  * c-basic-offset: 4
 384  * End:
 385  */