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  * VLAN TRUNKING PROTOCOL (VTP)
  16  *
  17  * Reference documentation:
  18  *  http://www.cisco.com/en/US/tech/tk389/tk689/technologies_tech_note09186a0080094c52.shtml
  19  *  http://www.cisco.com/warp/public/473/21.html
  20  *  http://www.cisco.com/univercd/cc/td/doc/product/lan/trsrb/frames.htm
  21  *
  22  * Original code ode by Carles Kishimoto <carles.kishimoto@gmail.com>
  23  */
  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;
 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     fn_printzp(ndo, tptr + 4, *(tptr + 3), NULL);
 149     ND_PRINT((ndo, ", %s: %u",
 150            tok2str(vtp_header_values, "Unknown", type),
 151            *(tptr+2)));
 152
 153     tptr += VTP_HEADER_LEN;
 154
 155     switch (type) {
 156
 157     case VTP_SUMMARY_ADV:
 158
 159         /*
 160          *  SUMMARY ADVERTISEMENT
 161          *
 162          *  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
 163          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 164          *  |     Version   |     Code      |    Followers  |    MmgtD Len  |
 165          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 166          *  |       Management Domain Name  (zero-padded to 32 bytes)       |
 167          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 168          *  |                    Configuration revision number              |
 169          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 170          *  |                  Updater Identity IP address                  |
 171          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 172          *  |                    Update Timestamp (12 bytes)                |
 173          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 174          *  |                        MD5 digest (16 bytes)                  |
 175          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 176          *
 177          */
 178
 179         ND_PRINT((ndo, "\n\t  Config Rev %x, Updater %s",
 180                EXTRACT_32BITS(tptr),
 181                ipaddr_string(ndo, tptr+4)));
 182         tptr += 8;
 183         ND_PRINT((ndo, ", Timestamp 0x%08x 0x%08x 0x%08x",
 184                EXTRACT_32BITS(tptr),
 185                EXTRACT_32BITS(tptr + 4),
 186                EXTRACT_32BITS(tptr + 8)));
 187         tptr += VTP_UPDATE_TIMESTAMP_LEN;
 188         ND_PRINT((ndo, ", MD5 digest: %08x%08x%08x%08x",
 189                EXTRACT_32BITS(tptr),
 190                EXTRACT_32BITS(tptr + 4),
 191                EXTRACT_32BITS(tptr + 8),
 192                EXTRACT_32BITS(tptr + 12)));
 193         tptr += VTP_MD5_DIGEST_LEN;
 194         break;
 195
 196     case VTP_SUBSET_ADV:
 197
 198         /*
 199          *  SUBSET ADVERTISEMENT
 200          *
 201          *  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
 202          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 203          *  |     Version   |     Code      |   Seq number  |    MmgtD Len  |
 204          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 205          *  |       Management Domain Name  (zero-padded to 32 bytes)       |
 206          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 207          *  |                    Configuration revision number              |
 208          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 209          *  |                         VLAN info field 1                     |
 210          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 211          *  |                         ................                      |
 212          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 213          *  |                         VLAN info field N                     |
 214          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 215          *
 216          */
 217
 218         ND_PRINT((ndo, ", Config Rev %x", EXTRACT_32BITS(tptr)));
 219
 220         /*
 221          *  VLAN INFORMATION
 222          *  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
 223          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 224          *  | V info len    |    Status     |  VLAN type    | VLAN name len |
 225          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 226          *  |       ISL vlan id             |            MTU size           |
 227          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 228          *  |                     802.10 index (SAID)                       |
 229          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 230          *  |                         VLAN name                             |
 231          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 232          *
 233          */
 234
 235         tptr += 4;
 236         while (tptr < (pptr+length)) {
 237
 238             len = *tptr;
 239             if (len == 0)
 240                 break;
 241
 242             ND_TCHECK2(*tptr, len);
 243
 244             vtp_vlan = (const struct vtp_vlan_*)tptr;
 245             ND_PRINT((ndo, "\n\tVLAN info status %s, type %s, VLAN-id %u, MTU %u, SAID 0x%08x, Name ",
 246                    tok2str(vtp_vlan_status,"Unknown",vtp_vlan->status),
 247                    tok2str(vtp_vlan_type_values,"Unknown",vtp_vlan->type),
 248                    EXTRACT_16BITS(&vtp_vlan->vlanid),
 249                    EXTRACT_16BITS(&vtp_vlan->mtu),
 250                    EXTRACT_32BITS(&vtp_vlan->index)));
 251             fn_printzp(ndo, tptr + VTP_VLAN_INFO_OFFSET, vtp_vlan->name_len, NULL);
 252
 253             /*
 254              * Vlan names are aligned to 32-bit boundaries.
 255              */
 256             len  -= VTP_VLAN_INFO_OFFSET + 4*((vtp_vlan->name_len + 3)/4);
 257             tptr += VTP_VLAN_INFO_OFFSET + 4*((vtp_vlan->name_len + 3)/4);
 258
 259             /* TLV information follows */
 260
 261             while (len > 0) {
 262
 263                 /*
 264                  * Cisco specs says 2 bytes for type + 2 bytes for length, take only 1
 265                  * See: http://www.cisco.com/univercd/cc/td/doc/product/lan/trsrb/frames.htm
 266                  */
 267                 type = *tptr;
 268                 tlv_len = *(tptr+1);
 269
 270                 ND_PRINT((ndo, "\n\t\t%s (0x%04x) TLV",
 271                        tok2str(vtp_vlan_tlv_values, "Unknown", type),
 272                        type));
 273
 274                 /*
 275                  * infinite loop check
 276                  */
 277                 if (type == 0 || tlv_len == 0) {
 278                     return;
 279                 }
 280
 281                 ND_TCHECK2(*tptr, tlv_len * 2 +2);
 282
 283                 tlv_value = EXTRACT_16BITS(tptr+2);
 284
 285                 switch (type) {
 286                 case VTP_VLAN_STE_HOP_COUNT:
 287                     ND_PRINT((ndo, ", %u", tlv_value));
 288                     break;
 289
 290                 case VTP_VLAN_PRUNING:
 291                     ND_PRINT((ndo, ", %s (%u)",
 292                            tlv_value == 1 ? "Enabled" : "Disabled",
 293                            tlv_value));
 294                     break;
 295
 296                 case VTP_VLAN_STP_TYPE:
 297                     ND_PRINT((ndo, ", %s (%u)",
 298                            tok2str(vtp_stp_type_values, "Unknown", tlv_value),
 299                            tlv_value));
 300                     break;
 301
 302                 case VTP_VLAN_BRIDGE_TYPE:
 303                     ND_PRINT((ndo, ", %s (%u)",
 304                            tlv_value == 1 ? "SRB" : "SRT",
 305                            tlv_value));
 306                     break;
 307
 308                 case VTP_VLAN_BACKUP_CRF_MODE:
 309                     ND_PRINT((ndo, ", %s (%u)",
 310                            tlv_value == 1 ? "Backup" : "Not backup",
 311                            tlv_value));
 312                     break;
 313
 314                     /*
 315                      * FIXME those are the defined TLVs that lack a decoder
 316                      * you are welcome to contribute code ;-)
 317                      */
 318
 319                 case VTP_VLAN_SOURCE_ROUTING_RING_NUMBER:
 320                 case VTP_VLAN_SOURCE_ROUTING_BRIDGE_NUMBER:
 321                 case VTP_VLAN_PARENT_VLAN:
 322                 case VTP_VLAN_TRANS_BRIDGED_VLAN:
 323                 case VTP_VLAN_ARP_HOP_COUNT:
 324                 default:
 325                     print_unknown_data(ndo, tptr, "\n\t\t  ", 2 + tlv_len*2);
 326                     break;
 327                 }
 328                 len -= 2 + tlv_len*2;
 329                 tptr += 2 + tlv_len*2;
 330             }
 331         }
 332         break;
 333
 334     case VTP_ADV_REQUEST:
 335
 336         /*
 337          *  ADVERTISEMENT REQUEST
 338          *
 339          *  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
 340          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 341          *  |     Version   |     Code      |   Reserved    |    MmgtD Len  |
 342          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 343          *  |       Management Domain Name  (zero-padded to 32 bytes)       |
 344          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 345          *  |                          Start value                          |
 346          *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 347          *
 348          */
 349
 350         ND_PRINT((ndo, "\n\tStart value: %u", EXTRACT_32BITS(tptr)));
 351         break;
 352
 353     case VTP_JOIN_MESSAGE:
 354
 355         /* FIXME - Could not find message format */
 356         break;
 357
 358     default:
 359         break;
 360     }
 361
 362     return;
 363
 364  trunc:
 365     ND_PRINT((ndo, "[|vtp]"));
 366 }
 367
 368 /*
 369  * Local Variables:
 370  * c-style: whitesmith
 371  * c-basic-offset: 4
 372  * End:
 373  */