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

   1 /*
   2  * Copyright (c) 1998-2006 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  * support for the IEEE "slow protocols" LACP, MARKER as per 802.3ad
  16  *                                       OAM as per 802.3ah
  17  *
  18  * Original code by Hannes Gredler (hannes@gredler.at)
  19  */
  20
  21 /* \summary: IEEE "slow protocols" (802.3ad/802.3ah) printer */
  22
  23 #ifdef HAVE_CONFIG_H
  24 #include <config.h>
  25 #endif
  26
  27 #include "netdissect-stdinc.h"
  28
  29 #include "netdissect.h"
  30 #include "extract.h"
  31 #include "addrtoname.h"
  32 #include "oui.h"
  33
  34 #define SLOW_PROTO_LACP                     1
  35 #define SLOW_PROTO_MARKER                   2
  36 #define SLOW_PROTO_OAM                      3
  37
  38 #define LACP_VERSION                        1
  39 #define MARKER_VERSION                      1
  40
  41 static const struct tok slow_proto_values[] = {
  42     { SLOW_PROTO_LACP, "LACP" },
  43     { SLOW_PROTO_MARKER, "MARKER" },
  44     { SLOW_PROTO_OAM, "OAM" },
  45     { 0, NULL}
  46 };
  47
  48 static const struct tok slow_oam_flag_values[] = {
  49     { 0x0001, "Link Fault" },
  50     { 0x0002, "Dying Gasp" },
  51     { 0x0004, "Critical Event" },
  52     { 0x0008, "Local Evaluating" },
  53     { 0x0010, "Local Stable" },
  54     { 0x0020, "Remote Evaluating" },
  55     { 0x0040, "Remote Stable" },
  56     { 0, NULL}
  57 };
  58
  59 #define SLOW_OAM_CODE_INFO          0x00
  60 #define SLOW_OAM_CODE_EVENT_NOTIF   0x01
  61 #define SLOW_OAM_CODE_VAR_REQUEST   0x02
  62 #define SLOW_OAM_CODE_VAR_RESPONSE  0x03
  63 #define SLOW_OAM_CODE_LOOPBACK_CTRL 0x04
  64 #define SLOW_OAM_CODE_PRIVATE       0xfe
  65
  66 static const struct tok slow_oam_code_values[] = {
  67     { SLOW_OAM_CODE_INFO, "Information" },
  68     { SLOW_OAM_CODE_EVENT_NOTIF, "Event Notification" },
  69     { SLOW_OAM_CODE_VAR_REQUEST, "Variable Request" },
  70     { SLOW_OAM_CODE_VAR_RESPONSE, "Variable Response" },
  71     { SLOW_OAM_CODE_LOOPBACK_CTRL, "Loopback Control" },
  72     { SLOW_OAM_CODE_PRIVATE, "Vendor Private" },
  73     { 0, NULL}
  74 };
  75
  76 struct slow_oam_info_t {
  77     nd_uint8_t info_type;
  78     nd_uint8_t info_length;
  79     nd_uint8_t oam_version;
  80     nd_uint16_t revision;
  81     nd_uint8_t state;
  82     nd_uint8_t oam_config;
  83     nd_uint16_t oam_pdu_config;
  84     nd_uint24_t oui;
  85     nd_uint32_t vendor_private;
  86 };
  87
  88 #define SLOW_OAM_INFO_TYPE_END_OF_TLV 0x00
  89 #define SLOW_OAM_INFO_TYPE_LOCAL 0x01
  90 #define SLOW_OAM_INFO_TYPE_REMOTE 0x02
  91 #define SLOW_OAM_INFO_TYPE_ORG_SPECIFIC 0xfe
  92
  93 static const struct tok slow_oam_info_type_values[] = {
  94     { SLOW_OAM_INFO_TYPE_END_OF_TLV, "End of TLV marker" },
  95     { SLOW_OAM_INFO_TYPE_LOCAL, "Local" },
  96     { SLOW_OAM_INFO_TYPE_REMOTE, "Remote" },
  97     { SLOW_OAM_INFO_TYPE_ORG_SPECIFIC, "Organization specific" },
  98     { 0, NULL}
  99 };
 100
 101 #define OAM_INFO_TYPE_PARSER_MASK 0x3
 102 static const struct tok slow_oam_info_type_state_parser_values[] = {
 103     { 0x00, "forwarding" },
 104     { 0x01, "looping back" },
 105     { 0x02, "discarding" },
 106     { 0x03, "reserved" },
 107     { 0, NULL}
 108 };
 109
 110 #define OAM_INFO_TYPE_MUX_MASK 0x4
 111 static const struct tok slow_oam_info_type_state_mux_values[] = {
 112     { 0x00, "forwarding" },
 113     { 0x04, "discarding" },
 114     { 0, NULL}
 115 };
 116
 117 static const struct tok slow_oam_info_type_oam_config_values[] = {
 118     { 0x01, "Active" },
 119     { 0x02, "Unidirectional" },
 120     { 0x04, "Remote-Loopback" },
 121     { 0x08, "Link-Events" },
 122     { 0x10, "Variable-Retrieval" },
 123     { 0, NULL}
 124 };
 125
 126 /* 11 Bits */
 127 #define OAM_INFO_TYPE_PDU_SIZE_MASK 0x7ff
 128
 129 #define SLOW_OAM_LINK_EVENT_END_OF_TLV 0x00
 130 #define SLOW_OAM_LINK_EVENT_ERR_SYM_PER 0x01
 131 #define SLOW_OAM_LINK_EVENT_ERR_FRM 0x02
 132 #define SLOW_OAM_LINK_EVENT_ERR_FRM_PER 0x03
 133 #define SLOW_OAM_LINK_EVENT_ERR_FRM_SUMM 0x04
 134 #define SLOW_OAM_LINK_EVENT_ORG_SPECIFIC 0xfe
 135
 136 static const struct tok slow_oam_link_event_values[] = {
 137     { SLOW_OAM_LINK_EVENT_END_OF_TLV, "End of TLV marker" },
 138     { SLOW_OAM_LINK_EVENT_ERR_SYM_PER, "Errored Symbol Period Event" },
 139     { SLOW_OAM_LINK_EVENT_ERR_FRM, "Errored Frame Event" },
 140     { SLOW_OAM_LINK_EVENT_ERR_FRM_PER, "Errored Frame Period Event" },
 141     { SLOW_OAM_LINK_EVENT_ERR_FRM_SUMM, "Errored Frame Seconds Summary Event" },
 142     { SLOW_OAM_LINK_EVENT_ORG_SPECIFIC, "Organization specific" },
 143     { 0, NULL}
 144 };
 145
 146 struct slow_oam_link_event_t {
 147     nd_uint8_t event_type;
 148     nd_uint8_t event_length;
 149     nd_uint16_t time_stamp;
 150     nd_uint64_t window;
 151     nd_uint64_t threshold;
 152     nd_uint64_t errors;
 153     nd_uint64_t errors_running_total;
 154     nd_uint32_t event_running_total;
 155 };
 156
 157 struct slow_oam_variablerequest_t {
 158     nd_uint8_t branch;
 159     nd_uint16_t leaf;
 160 };
 161
 162 struct slow_oam_variableresponse_t {
 163     nd_uint8_t branch;
 164     nd_uint16_t leaf;
 165     nd_uint8_t length;
 166 };
 167
 168 struct slow_oam_loopbackctrl_t {
 169     nd_uint8_t command;
 170 };
 171
 172 static const struct tok slow_oam_loopbackctrl_cmd_values[] = {
 173     { 0x01, "Enable OAM Remote Loopback" },
 174     { 0x02, "Disable OAM Remote Loopback" },
 175     { 0, NULL}
 176 };
 177
 178 struct tlv_header_t {
 179     nd_uint8_t type;
 180     nd_uint8_t length;
 181 };
 182
 183 #define LACP_MARKER_TLV_TERMINATOR     0x00  /* same code for LACP and Marker */
 184
 185 #define LACP_TLV_ACTOR_INFO            0x01
 186 #define LACP_TLV_PARTNER_INFO          0x02
 187 #define LACP_TLV_COLLECTOR_INFO        0x03
 188
 189 #define MARKER_TLV_MARKER_INFO         0x01
 190
 191 static const struct tok slow_tlv_values[] = {
 192     { (SLOW_PROTO_LACP << 8) + LACP_MARKER_TLV_TERMINATOR, "Terminator"},
 193     { (SLOW_PROTO_LACP << 8) + LACP_TLV_ACTOR_INFO, "Actor Information"},
 194     { (SLOW_PROTO_LACP << 8) + LACP_TLV_PARTNER_INFO, "Partner Information"},
 195     { (SLOW_PROTO_LACP << 8) + LACP_TLV_COLLECTOR_INFO, "Collector Information"},
 196
 197     { (SLOW_PROTO_MARKER << 8) + LACP_MARKER_TLV_TERMINATOR, "Terminator"},
 198     { (SLOW_PROTO_MARKER << 8) + MARKER_TLV_MARKER_INFO, "Marker Information"},
 199     { 0, NULL}
 200 };
 201
 202 struct lacp_tlv_actor_partner_info_t {
 203     nd_uint16_t sys_pri;
 204     nd_mac_addr sys;
 205     nd_uint16_t key;
 206     nd_uint16_t port_pri;
 207     nd_uint16_t port;
 208     nd_uint8_t state;
 209     nd_byte    pad[3];
 210 };
 211
 212 static const struct tok lacp_tlv_actor_partner_info_state_values[] = {
 213     { 0x01, "Activity"},
 214     { 0x02, "Timeout"},
 215     { 0x04, "Aggregation"},
 216     { 0x08, "Synchronization"},
 217     { 0x10, "Collecting"},
 218     { 0x20, "Distributing"},
 219     { 0x40, "Default"},
 220     { 0x80, "Expired"},
 221     { 0, NULL}
 222 };
 223
 224 struct lacp_tlv_collector_info_t {
 225     nd_uint16_t max_delay;
 226     nd_byte     pad[12];
 227 };
 228
 229 struct marker_tlv_marker_info_t {
 230     nd_uint16_t req_port;
 231     nd_mac_addr req_sys;
 232     nd_uint32_t req_trans_id;
 233     nd_byte     pad[2];
 234 };
 235
 236 struct lacp_marker_tlv_terminator_t {
 237     nd_byte     pad[50];
 238 };
 239
 240 static void slow_marker_lacp_print(netdissect_options *, const u_char *, u_int, u_int);
 241 static void slow_oam_print(netdissect_options *, const u_char *, u_int);
 242
 243 void
 244 slow_print(netdissect_options *ndo,
 245            const u_char *pptr, u_int len)
 246 {
 247     int print_version;
 248     u_int subtype;
 249
 250     if (len < 1)
 251         goto tooshort;
 252     ND_TCHECK_1(pptr);
 253     subtype = EXTRACT_U_1(pptr);
 254
 255     /*
 256      * Sanity checking of the header.
 257      */
 258     switch (subtype) {
 259     case SLOW_PROTO_LACP:
 260         if (len < 2)
 261             goto tooshort;
 262         ND_TCHECK_1(pptr + 1);
 263         if (EXTRACT_U_1(pptr + 1) != LACP_VERSION) {
 264             ND_PRINT("LACP version %u packet not supported", EXTRACT_U_1(pptr + 1));
 265             return;
 266         }
 267         print_version = 1;
 268         break;
 269
 270     case SLOW_PROTO_MARKER:
 271         if (len < 2)
 272             goto tooshort;
 273         ND_TCHECK_1(pptr + 1);
 274         if (EXTRACT_U_1(pptr + 1) != MARKER_VERSION) {
 275             ND_PRINT("MARKER version %u packet not supported", EXTRACT_U_1(pptr + 1));
 276             return;
 277         }
 278         print_version = 1;
 279         break;
 280
 281     case SLOW_PROTO_OAM: /* fall through */
 282         print_version = 0;
 283         break;
 284
 285     default:
 286         /* print basic information and exit */
 287         print_version = -1;
 288         break;
 289     }
 290
 291     if (print_version == 1) {
 292         ND_PRINT("%sv%u, length %u",
 293                tok2str(slow_proto_values, "unknown (%u)", subtype),
 294                EXTRACT_U_1((pptr + 1)),
 295                len);
 296     } else {
 297         /* some slow protos don't have a version number in the header */
 298         ND_PRINT("%s, length %u",
 299                tok2str(slow_proto_values, "unknown (%u)", subtype),
 300                len);
 301     }
 302
 303     /* unrecognized subtype */
 304     if (print_version == -1) {
 305         print_unknown_data(ndo, pptr, "\n\t", len);
 306         return;
 307     }
 308
 309     if (!ndo->ndo_vflag)
 310         return;
 311
 312     switch (subtype) {
 313     default: /* should not happen */
 314         break;
 315
 316     case SLOW_PROTO_OAM:
 317         /* skip subtype */
 318         len -= 1;
 319         pptr += 1;
 320         slow_oam_print(ndo, pptr, len);
 321         break;
 322
 323     case SLOW_PROTO_LACP:   /* LACP and MARKER share the same semantics */
 324     case SLOW_PROTO_MARKER:
 325         /* skip subtype and version */
 326         len -= 2;
 327         pptr += 2;
 328         slow_marker_lacp_print(ndo, pptr, len, subtype);
 329         break;
 330     }
 331     return;
 332
 333 tooshort:
 334     if (!ndo->ndo_vflag)
 335         ND_PRINT(" (packet is too short)");
 336     else
 337         ND_PRINT("\n\t\t packet is too short");
 338     return;
 339
 340 trunc:
 341     if (!ndo->ndo_vflag)
 342         ND_PRINT(" (packet exceeded snapshot)");
 343     else
 344         ND_PRINT("\n\t\t packet exceeded snapshot");
 345 }
 346
 347 static void
 348 slow_marker_lacp_print(netdissect_options *ndo,
 349                        const u_char *tptr, u_int tlen,
 350                        u_int proto_subtype)
 351 {
 352     const struct tlv_header_t *tlv_header;
 353     const u_char *tlv_tptr;
 354     u_int tlv_type, tlv_len, tlv_tlen;
 355
 356     union {
 357         const struct lacp_marker_tlv_terminator_t *lacp_marker_tlv_terminator;
 358         const struct lacp_tlv_actor_partner_info_t *lacp_tlv_actor_partner_info;
 359         const struct lacp_tlv_collector_info_t *lacp_tlv_collector_info;
 360         const struct marker_tlv_marker_info_t *marker_tlv_marker_info;
 361     } tlv_ptr;
 362
 363     while(tlen>0) {
 364         /* is the packet big enough to include the tlv header ? */
 365         if (tlen < sizeof(struct tlv_header_t))
 366             goto tooshort;
 367         /* did we capture enough for fully decoding the tlv header ? */
 368         ND_TCHECK_LEN(tptr, sizeof(struct tlv_header_t));
 369         tlv_header = (const struct tlv_header_t *)tptr;
 370         tlv_type = EXTRACT_U_1(tlv_header->type);
 371         tlv_len = EXTRACT_U_1(tlv_header->length);
 372
 373         ND_PRINT("\n\t%s TLV (0x%02x), length %u",
 374                tok2str(slow_tlv_values,
 375                        "Unknown",
 376                        (proto_subtype << 8) + tlv_type),
 377                tlv_type,
 378                tlv_len);
 379
 380         if (tlv_type == LACP_MARKER_TLV_TERMINATOR) {
 381             /*
 382              * This TLV has a length of zero, and means there are no
 383              * more TLVs to process.
 384              */
 385             return;
 386         }
 387
 388         /* length includes the type and length fields */
 389         if (tlv_len < sizeof(struct tlv_header_t)) {
 390             ND_PRINT("\n\t    ERROR: illegal length - should be >= %lu",
 391                    (unsigned long) sizeof(struct tlv_header_t));
 392             return;
 393         }
 394
 395         /* is the packet big enough to include the tlv ? */
 396         if (tlen < tlv_len)
 397             goto tooshort;
 398         /* did we capture enough for fully decoding the tlv ? */
 399         ND_TCHECK_LEN(tptr, tlv_len);
 400
 401         tlv_tptr=tptr+sizeof(struct tlv_header_t);
 402         tlv_tlen=tlv_len-sizeof(struct tlv_header_t);
 403
 404         switch((proto_subtype << 8) + tlv_type) {
 405
 406             /* those two TLVs have the same structure -> fall through */
 407         case ((SLOW_PROTO_LACP << 8) + LACP_TLV_ACTOR_INFO):
 408         case ((SLOW_PROTO_LACP << 8) + LACP_TLV_PARTNER_INFO):
 409             if (tlv_tlen !=
 410                 sizeof(struct lacp_tlv_actor_partner_info_t)) {
 411                 ND_PRINT("\n\t    ERROR: illegal length - should be %lu",
 412                        (unsigned long) (sizeof(struct tlv_header_t) + sizeof(struct lacp_tlv_actor_partner_info_t)));
 413                 goto badlength;
 414             }
 415
 416             tlv_ptr.lacp_tlv_actor_partner_info = (const struct lacp_tlv_actor_partner_info_t *)tlv_tptr;
 417
 418             ND_PRINT("\n\t  System %s, System Priority %u, Key %u"
 419                    ", Port %u, Port Priority %u\n\t  State Flags [%s]",
 420                    etheraddr_string(ndo, tlv_ptr.lacp_tlv_actor_partner_info->sys),
 421                    EXTRACT_BE_U_2(tlv_ptr.lacp_tlv_actor_partner_info->sys_pri),
 422                    EXTRACT_BE_U_2(tlv_ptr.lacp_tlv_actor_partner_info->key),
 423                    EXTRACT_BE_U_2(tlv_ptr.lacp_tlv_actor_partner_info->port),
 424                    EXTRACT_BE_U_2(tlv_ptr.lacp_tlv_actor_partner_info->port_pri),
 425                    bittok2str(lacp_tlv_actor_partner_info_state_values,
 426                               "none",
 427                               EXTRACT_U_1(tlv_ptr.lacp_tlv_actor_partner_info->state)));
 428
 429             break;
 430
 431         case ((SLOW_PROTO_LACP << 8) + LACP_TLV_COLLECTOR_INFO):
 432             if (tlv_tlen !=
 433                 sizeof(struct lacp_tlv_collector_info_t)) {
 434                 ND_PRINT("\n\t    ERROR: illegal length - should be %lu",
 435                        (unsigned long) (sizeof(struct tlv_header_t) + sizeof(struct lacp_tlv_collector_info_t)));
 436                 goto badlength;
 437             }
 438
 439             tlv_ptr.lacp_tlv_collector_info = (const struct lacp_tlv_collector_info_t *)tlv_tptr;
 440
 441             ND_PRINT("\n\t  Max Delay %u",
 442                    EXTRACT_BE_U_2(tlv_ptr.lacp_tlv_collector_info->max_delay));
 443
 444             break;
 445
 446         case ((SLOW_PROTO_MARKER << 8) + MARKER_TLV_MARKER_INFO):
 447             if (tlv_tlen !=
 448                 sizeof(struct marker_tlv_marker_info_t)) {
 449                 ND_PRINT("\n\t    ERROR: illegal length - should be %lu",
 450                        (unsigned long) (sizeof(struct tlv_header_t) + sizeof(struct marker_tlv_marker_info_t)));
 451                 goto badlength;
 452             }
 453
 454             tlv_ptr.marker_tlv_marker_info = (const struct marker_tlv_marker_info_t *)tlv_tptr;
 455
 456             ND_PRINT("\n\t  Request System %s, Request Port %u, Request Transaction ID 0x%08x",
 457                    etheraddr_string(ndo, tlv_ptr.marker_tlv_marker_info->req_sys),
 458                    EXTRACT_BE_U_2(tlv_ptr.marker_tlv_marker_info->req_port),
 459                    EXTRACT_BE_U_4(tlv_ptr.marker_tlv_marker_info->req_trans_id));
 460
 461             break;
 462
 463         default:
 464             if (ndo->ndo_vflag <= 1)
 465                 print_unknown_data(ndo, tlv_tptr, "\n\t  ", tlv_tlen);
 466             break;
 467         }
 468
 469     badlength:
 470         /* do we want to see an additional hexdump ? */
 471         if (ndo->ndo_vflag > 1) {
 472             print_unknown_data(ndo, tptr+sizeof(struct tlv_header_t), "\n\t  ",
 473                                tlv_len-sizeof(struct tlv_header_t));
 474         }
 475
 476         tptr+=tlv_len;
 477         tlen-=tlv_len;
 478     }
 479     return;
 480
 481 tooshort:
 482     ND_PRINT("\n\t\t packet is too short");
 483     return;
 484
 485 trunc:
 486     ND_PRINT("\n\t\t packet exceeded snapshot");
 487 }
 488
 489 static void
 490 slow_oam_print(netdissect_options *ndo,
 491                const u_char *tptr, u_int tlen)
 492 {
 493     uint8_t code;
 494     uint8_t type, length;
 495     uint8_t state;
 496     uint8_t command;
 497     u_int hexdump;
 498
 499     struct slow_oam_common_header_t {
 500         nd_uint16_t flags;
 501         nd_uint8_t code;
 502     };
 503
 504     struct slow_oam_tlv_header_t {
 505         nd_uint8_t type;
 506         nd_uint8_t length;
 507     };
 508
 509     union {
 510         const struct slow_oam_common_header_t *slow_oam_common_header;
 511         const struct slow_oam_tlv_header_t *slow_oam_tlv_header;
 512     } ptr;
 513
 514     union {
 515         const struct slow_oam_info_t *slow_oam_info;
 516         const struct slow_oam_link_event_t *slow_oam_link_event;
 517         const struct slow_oam_variablerequest_t *slow_oam_variablerequest;
 518         const struct slow_oam_variableresponse_t *slow_oam_variableresponse;
 519         const struct slow_oam_loopbackctrl_t *slow_oam_loopbackctrl;
 520     } tlv;
 521
 522     ptr.slow_oam_common_header = (const struct slow_oam_common_header_t *)tptr;
 523     if (tlen < sizeof(*ptr.slow_oam_common_header))
 524         goto tooshort;
 525     ND_TCHECK_SIZE(ptr.slow_oam_common_header);
 526     tptr += sizeof(struct slow_oam_common_header_t);
 527     tlen -= sizeof(struct slow_oam_common_header_t);
 528
 529     code = EXTRACT_U_1(ptr.slow_oam_common_header->code);
 530     ND_PRINT("\n\tCode %s OAM PDU, Flags [%s]",
 531            tok2str(slow_oam_code_values, "Unknown (%u)", code),
 532            bittok2str(slow_oam_flag_values,
 533                       "none",
 534                       EXTRACT_BE_U_2(ptr.slow_oam_common_header->flags)));
 535
 536     switch (code) {
 537     case SLOW_OAM_CODE_INFO:
 538         while (tlen > 0) {
 539             ptr.slow_oam_tlv_header = (const struct slow_oam_tlv_header_t *)tptr;
 540             if (tlen < sizeof(*ptr.slow_oam_tlv_header))
 541                 goto tooshort;
 542             ND_TCHECK_SIZE(ptr.slow_oam_tlv_header);
 543             type = EXTRACT_U_1(ptr.slow_oam_tlv_header->type);
 544             length = EXTRACT_U_1(ptr.slow_oam_tlv_header->length);
 545             ND_PRINT("\n\t  %s Information Type (%u), length %u",
 546                    tok2str(slow_oam_info_type_values, "Reserved", type),
 547                    type,
 548                    length);
 549
 550             if (type == SLOW_OAM_INFO_TYPE_END_OF_TLV) {
 551                 /*
 552                  * As IEEE Std 802.3-2015 says for the End of TLV Marker,
 553                  * "(the length and value of the Type 0x00 TLV can be ignored)".
 554                  */
 555                 return;
 556             }
 557
 558             /* length includes the type and length fields */
 559             if (length < sizeof(struct slow_oam_tlv_header_t)) {
 560                 ND_PRINT("\n\t    ERROR: illegal length - should be >= %u",
 561                        (u_int)sizeof(struct slow_oam_tlv_header_t));
 562                 return;
 563             }
 564
 565             if (tlen < length)
 566                 goto tooshort;
 567             ND_TCHECK_LEN(tptr, length);
 568
 569             hexdump = FALSE;
 570             switch (type) {
 571             case SLOW_OAM_INFO_TYPE_LOCAL: /* identical format - fall through */
 572             case SLOW_OAM_INFO_TYPE_REMOTE:
 573                 tlv.slow_oam_info = (const struct slow_oam_info_t *)tptr;
 574
 575                 if (EXTRACT_U_1(tlv.slow_oam_info->info_length) !=
 576                     sizeof(struct slow_oam_info_t)) {
 577                     ND_PRINT("\n\t    ERROR: illegal length - should be %lu",
 578                            (unsigned long) sizeof(struct slow_oam_info_t));
 579                     hexdump = TRUE;
 580                     goto badlength_code_info;
 581                 }
 582
 583                 ND_PRINT("\n\t    OAM-Version %u, Revision %u",
 584                        EXTRACT_U_1(tlv.slow_oam_info->oam_version),
 585                        EXTRACT_BE_U_2(tlv.slow_oam_info->revision));
 586
 587                 state = EXTRACT_U_1(tlv.slow_oam_info->state);
 588                 ND_PRINT("\n\t    State-Parser-Action %s, State-MUX-Action %s",
 589                        tok2str(slow_oam_info_type_state_parser_values, "Reserved",
 590                                state & OAM_INFO_TYPE_PARSER_MASK),
 591                        tok2str(slow_oam_info_type_state_mux_values, "Reserved",
 592                                state & OAM_INFO_TYPE_MUX_MASK));
 593                 ND_PRINT("\n\t    OAM-Config Flags [%s], OAM-PDU-Config max-PDU size %u",
 594                        bittok2str(slow_oam_info_type_oam_config_values, "none",
 595                                   EXTRACT_U_1(tlv.slow_oam_info->oam_config)),
 596                        EXTRACT_BE_U_2(tlv.slow_oam_info->oam_pdu_config) &
 597                        OAM_INFO_TYPE_PDU_SIZE_MASK);
 598                 ND_PRINT("\n\t    OUI %s (0x%06x), Vendor-Private 0x%08x",
 599                        tok2str(oui_values, "Unknown",
 600                                EXTRACT_BE_U_3(tlv.slow_oam_info->oui)),
 601                        EXTRACT_BE_U_3(tlv.slow_oam_info->oui),
 602                        EXTRACT_BE_U_4(tlv.slow_oam_info->vendor_private));
 603                 break;
 604
 605             case SLOW_OAM_INFO_TYPE_ORG_SPECIFIC:
 606                 hexdump = TRUE;
 607                 break;
 608
 609             default:
 610                 hexdump = TRUE;
 611                 break;
 612             }
 613
 614         badlength_code_info:
 615             /* do we also want to see a hex dump ? */
 616             if (ndo->ndo_vflag > 1 || hexdump==TRUE) {
 617                 print_unknown_data(ndo, tptr, "\n\t  ",
 618                                    length);
 619             }
 620
 621             tlen -= length;
 622             tptr += length;
 623         }
 624         break;
 625
 626     case SLOW_OAM_CODE_EVENT_NOTIF:
 627         /* Sequence number */
 628         if (tlen < 2)
 629             goto tooshort;
 630         ND_TCHECK_2(tptr);
 631         ND_PRINT("\n\t  Sequence Number %u", EXTRACT_BE_U_2(tptr));
 632         tlen -= 2;
 633         tptr += 2;
 634
 635         /* TLVs */
 636         while (tlen > 0) {
 637             ptr.slow_oam_tlv_header = (const struct slow_oam_tlv_header_t *)tptr;
 638             if (tlen < sizeof(*ptr.slow_oam_tlv_header))
 639                 goto tooshort;
 640             ND_TCHECK_SIZE(ptr.slow_oam_tlv_header);
 641             type = EXTRACT_U_1(ptr.slow_oam_tlv_header->type);
 642             length = EXTRACT_U_1(ptr.slow_oam_tlv_header->length);
 643             ND_PRINT("\n\t  %s Link Event Type (%u), length %u",
 644                    tok2str(slow_oam_link_event_values, "Reserved",
 645                            type),
 646                    type,
 647                    length);
 648
 649             if (type == SLOW_OAM_INFO_TYPE_END_OF_TLV) {
 650                 /*
 651                  * As IEEE Std 802.3-2015 says for the End of TLV Marker,
 652                  * "(the length and value of the Type 0x00 TLV can be ignored)".
 653                  */
 654                 return;
 655             }
 656
 657             /* length includes the type and length fields */
 658             if (length < sizeof(struct slow_oam_tlv_header_t)) {
 659                 ND_PRINT("\n\t    ERROR: illegal length - should be >= %u",
 660                        (u_int)sizeof(struct slow_oam_tlv_header_t));
 661                 return;
 662             }
 663
 664             if (tlen < length)
 665                 goto tooshort;
 666             ND_TCHECK_LEN(tptr, length);
 667
 668             hexdump = FALSE;
 669             switch (type) {
 670             case SLOW_OAM_LINK_EVENT_ERR_SYM_PER: /* identical format - fall through */
 671             case SLOW_OAM_LINK_EVENT_ERR_FRM:
 672             case SLOW_OAM_LINK_EVENT_ERR_FRM_PER:
 673             case SLOW_OAM_LINK_EVENT_ERR_FRM_SUMM:
 674                 tlv.slow_oam_link_event = (const struct slow_oam_link_event_t *)tptr;
 675
 676                 if (EXTRACT_U_1(tlv.slow_oam_link_event->event_length) !=
 677                     sizeof(struct slow_oam_link_event_t)) {
 678                     ND_PRINT("\n\t    ERROR: illegal length - should be %lu",
 679                            (unsigned long) sizeof(struct slow_oam_link_event_t));
 680                     hexdump = TRUE;
 681                     goto badlength_event_notif;
 682                 }
 683
 684                 ND_PRINT("\n\t    Timestamp %u ms, Errored Window %" PRIu64
 685                        "\n\t    Errored Threshold %" PRIu64
 686                        "\n\t    Errors %" PRIu64
 687                        "\n\t    Error Running Total %" PRIu64
 688                        "\n\t    Event Running Total %u",
 689                        EXTRACT_BE_U_2(tlv.slow_oam_link_event->time_stamp)*100,
 690                        EXTRACT_BE_U_8(tlv.slow_oam_link_event->window),
 691                        EXTRACT_BE_U_8(tlv.slow_oam_link_event->threshold),
 692                        EXTRACT_BE_U_8(tlv.slow_oam_link_event->errors),
 693                        EXTRACT_BE_U_8(tlv.slow_oam_link_event->errors_running_total),
 694                        EXTRACT_BE_U_4(tlv.slow_oam_link_event->event_running_total));
 695                 break;
 696
 697             case SLOW_OAM_LINK_EVENT_ORG_SPECIFIC:
 698                 hexdump = TRUE;
 699                 break;
 700
 701             default:
 702                 hexdump = TRUE;
 703                 break;
 704             }
 705
 706         badlength_event_notif:
 707             /* do we also want to see a hex dump ? */
 708             if (ndo->ndo_vflag > 1 || hexdump==TRUE) {
 709                 print_unknown_data(ndo, tptr, "\n\t  ",
 710                                    length);
 711             }
 712
 713             tlen -= length;
 714             tptr += length;
 715         }
 716         break;
 717
 718     case SLOW_OAM_CODE_LOOPBACK_CTRL:
 719         tlv.slow_oam_loopbackctrl = (const struct slow_oam_loopbackctrl_t *)tptr;
 720         if (tlen < sizeof(*tlv.slow_oam_loopbackctrl))
 721             goto tooshort;
 722         ND_TCHECK_SIZE(tlv.slow_oam_loopbackctrl);
 723         command = EXTRACT_U_1(tlv.slow_oam_loopbackctrl->command);
 724         ND_PRINT("\n\t  Command %s (%u)",
 725                tok2str(slow_oam_loopbackctrl_cmd_values,
 726                        "Unknown",
 727                        command),
 728                command);
 729         tptr ++;
 730         tlen --;
 731         break;
 732
 733         /*
 734          * FIXME those are the defined codes that lack a decoder
 735          * you are welcome to contribute code ;-)
 736          */
 737     case SLOW_OAM_CODE_VAR_REQUEST:
 738     case SLOW_OAM_CODE_VAR_RESPONSE:
 739     case SLOW_OAM_CODE_PRIVATE:
 740     default:
 741         if (ndo->ndo_vflag <= 1) {
 742             print_unknown_data(ndo, tptr, "\n\t  ", tlen);
 743         }
 744         break;
 745     }
 746     return;
 747
 748 tooshort:
 749     ND_PRINT("\n\t\t packet is too short");
 750     return;
 751
 752 trunc:
 753     ND_PRINT("\n\t\t packet exceeded snapshot");
 754 }