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

   1 /*
   2  * Copyright (c) 1994, 1995, 1996, 1997
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that: (1) source code distributions
   7  * retain the above copyright notice and this paragraph in its entirety, (2)
   8  * distributions including binary code include the above copyright notice and
   9  * this paragraph in its entirety in the documentation or other materials
  10  * provided with the distribution, and (3) all advertising materials mentioning
  11  * features or use of this software display the following acknowledgement:
  12  * ``This product includes software developed by the University of California,
  13  * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
  14  * the University nor the names of its contributors may be used to endorse
  15  * or promote products derived from this software without specific prior
  16  * written permission.
  17  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
  18  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
  19  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  20  */
  21
  22 /* \summary: Asynchronous Transfer Mode (ATM) printer */
  23
  24 #ifdef HAVE_CONFIG_H
  25 #include <config.h>
  26 #endif
  27
  28 #include "netdissect-stdinc.h"
  29
  30 #include "netdissect.h"
  31 #include "extract.h"
  32 #include "addrtoname.h"
  33 #include "atm.h"
  34 #include "llc.h"
  35
  36 /* start of the original atmuni31.h */
  37
  38 /*
  39  * Copyright (c) 1997 Yen Yen Lim and North Dakota State University
  40  * All rights reserved.
  41  *
  42  * Redistribution and use in source and binary forms, with or without
  43  * modification, are permitted provided that the following conditions
  44  * are met:
  45  * 1. Redistributions of source code must retain the above copyright
  46  *    notice, this list of conditions and the following disclaimer.
  47  * 2. Redistributions in binary form must reproduce the above copyright
  48  *    notice, this list of conditions and the following disclaimer in the
  49  *    documentation and/or other materials provided with the distribution.
  50  * 3. All advertising materials mentioning features or use of this software
  51  *    must display the following acknowledgement:
  52  *      This product includes software developed by Yen Yen Lim and
  53         North Dakota State University
  54  * 4. The name of the author may not be used to endorse or promote products
  55  *    derived from this software without specific prior written permission.
  56  *
  57  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  58  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  59  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  60  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
  61  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  62  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  63  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  64  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  65  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
  66  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  67  * POSSIBILITY OF SUCH DAMAGE.
  68  */
  69
  70 /* Based on UNI3.1 standard by ATM Forum */
  71
  72 /* ATM traffic types based on VPI=0 and (the following VCI */
  73 #define VCI_PPC                 0x05    /* Point-to-point signal msg */
  74 #define VCI_BCC                 0x02    /* Broadcast signal msg */
  75 #define VCI_OAMF4SC             0x03    /* Segment OAM F4 flow cell */
  76 #define VCI_OAMF4EC             0x04    /* End-to-end OAM F4 flow cell */
  77 #define VCI_METAC               0x01    /* Meta signal msg */
  78 #define VCI_ILMIC               0x10    /* ILMI msg */
  79
  80 /* Q.2931 signalling messages */
  81 #define CALL_PROCEED            0x02    /* call proceeding */
  82 #define CONNECT                 0x07    /* connect */
  83 #define CONNECT_ACK             0x0f    /* connect_ack */
  84 #define SETUP                   0x05    /* setup */
  85 #define RELEASE                 0x4d    /* release */
  86 #define RELEASE_DONE            0x5a    /* release_done */
  87 #define RESTART                 0x46    /* restart */
  88 #define RESTART_ACK             0x4e    /* restart ack */
  89 #define STATUS                  0x7d    /* status */
  90 #define STATUS_ENQ              0x75    /* status ack */
  91 #define ADD_PARTY               0x80    /* add party */
  92 #define ADD_PARTY_ACK           0x81    /* add party ack */
  93 #define ADD_PARTY_REJ           0x82    /* add party rej */
  94 #define DROP_PARTY              0x83    /* drop party */
  95 #define DROP_PARTY_ACK          0x84    /* drop party ack */
  96
  97 /* Information Element Parameters in the signalling messages */
  98 #define CAUSE                   0x08    /* cause */
  99 #define ENDPT_REF               0x54    /* endpoint reference */
 100 #define AAL_PARA                0x58    /* ATM adaptation layer parameters */
 101 #define TRAFF_DESCRIP           0x59    /* atm traffic descriptors */
 102 #define CONNECT_ID              0x5a    /* connection identifier */
 103 #define QOS_PARA                0x5c    /* quality of service parameters */
 104 #define B_HIGHER                0x5d    /* broadband higher layer information */
 105 #define B_BEARER                0x5e    /* broadband bearer capability */
 106 #define B_LOWER                 0x5f    /* broadband lower information */
 107 #define CALLING_PARTY           0x6c    /* calling party number */
 108 #define CALLED_PARTY            0x70    /* called party nmber */
 109
 110 #define Q2931                   0x09
 111
 112 /* Q.2931 signalling general messages format */
 113 #define PROTO_POS       0       /* offset of protocol discriminator */
 114 #define CALL_REF_POS    2       /* offset of call reference value */
 115 #define MSG_TYPE_POS    5       /* offset of message type */
 116 #define MSG_LEN_POS     7       /* offset of mesage length */
 117 #define IE_BEGIN_POS    9       /* offset of first information element */
 118
 119 /* format of signalling messages */
 120 #define TYPE_POS        0
 121 #define LEN_POS         2
 122 #define FIELD_BEGIN_POS 4
 123
 124 /* end of the original atmuni31.h */
 125
 126
 127 #define OAM_CRC10_MASK 0x3ff
 128 #define OAM_PAYLOAD_LEN 48
 129 #define OAM_FUNCTION_SPECIFIC_LEN 45 /* this excludes crc10 and cell-type/function-type */
 130 #define OAM_CELLTYPE_FUNCTYPE_LEN 1
 131
 132 static const struct tok oam_f_values[] = {
 133     { VCI_OAMF4SC, "OAM F4 (segment)" },
 134     { VCI_OAMF4EC, "OAM F4 (end)" },
 135     { 0, NULL }
 136 };
 137
 138 static const struct tok atm_pty_values[] = {
 139     { 0x0, "user data, uncongested, SDU 0" },
 140     { 0x1, "user data, uncongested, SDU 1" },
 141     { 0x2, "user data, congested, SDU 0" },
 142     { 0x3, "user data, congested, SDU 1" },
 143     { 0x4, "VCC OAM F5 flow segment" },
 144     { 0x5, "VCC OAM F5 flow end-to-end" },
 145     { 0x6, "Traffic Control and resource Mgmt" },
 146     { 0, NULL }
 147 };
 148
 149 #define OAM_CELLTYPE_FM 0x1
 150 #define OAM_CELLTYPE_PM 0x2
 151 #define OAM_CELLTYPE_AD 0x8
 152 #define OAM_CELLTYPE_SM 0xf
 153
 154 static const struct tok oam_celltype_values[] = {
 155     { OAM_CELLTYPE_FM, "Fault Management" },
 156     { OAM_CELLTYPE_PM, "Performance Management" },
 157     { OAM_CELLTYPE_AD, "activate/deactivate" },
 158     { OAM_CELLTYPE_SM, "System Management" },
 159     { 0, NULL }
 160 };
 161
 162 #define OAM_FM_FUNCTYPE_AIS       0x0
 163 #define OAM_FM_FUNCTYPE_RDI       0x1
 164 #define OAM_FM_FUNCTYPE_CONTCHECK 0x4
 165 #define OAM_FM_FUNCTYPE_LOOPBACK  0x8
 166
 167 static const struct tok oam_fm_functype_values[] = {
 168     { OAM_FM_FUNCTYPE_AIS, "AIS" },
 169     { OAM_FM_FUNCTYPE_RDI, "RDI" },
 170     { OAM_FM_FUNCTYPE_CONTCHECK, "Continuity Check" },
 171     { OAM_FM_FUNCTYPE_LOOPBACK, "Loopback" },
 172     { 0, NULL }
 173 };
 174
 175 static const struct tok oam_pm_functype_values[] = {
 176     { 0x0, "Forward Monitoring" },
 177     { 0x1, "Backward Reporting" },
 178     { 0x2, "Monitoring and Reporting" },
 179     { 0, NULL }
 180 };
 181
 182 static const struct tok oam_ad_functype_values[] = {
 183     { 0x0, "Performance Monitoring" },
 184     { 0x1, "Continuity Check" },
 185     { 0, NULL }
 186 };
 187
 188 #define OAM_FM_LOOPBACK_INDICATOR_MASK 0x1
 189
 190 static const struct tok oam_fm_loopback_indicator_values[] = {
 191     { 0x0, "Reply" },
 192     { 0x1, "Request" },
 193     { 0, NULL }
 194 };
 195
 196 static const struct tok *oam_functype_values[16] = {
 197     NULL,
 198     oam_fm_functype_values, /* 1 */
 199     oam_pm_functype_values, /* 2 */
 200     NULL,
 201     NULL,
 202     NULL,
 203     NULL,
 204     NULL,
 205     oam_ad_functype_values, /* 8 */
 206     NULL,
 207     NULL,
 208     NULL,
 209     NULL,
 210     NULL,
 211     NULL,
 212     NULL
 213 };
 214
 215 /*
 216  * Print an RFC 1483 LLC-encapsulated ATM frame.
 217  */
 218 static u_int
 219 atm_llc_print(netdissect_options *ndo,
 220               const u_char *p, int length, int caplen)
 221 {
 222         int llc_hdrlen;
 223
 224         llc_hdrlen = llc_print(ndo, p, length, caplen, NULL, NULL);
 225         if (llc_hdrlen < 0) {
 226                 /* packet not known, print raw packet */
 227                 if (!ndo->ndo_suppress_default_print)
 228                         ND_DEFAULTPRINT(p, caplen);
 229                 llc_hdrlen = -llc_hdrlen;
 230         }
 231         return (llc_hdrlen);
 232 }
 233
 234 /*
 235  * Given a SAP value, generate the LLC header value for a UI packet
 236  * with that SAP as the source and destination SAP.
 237  */
 238 #define LLC_UI_HDR(sap) ((sap)<<16 | (sap<<8) | 0x03)
 239
 240 /*
 241  * This is the top level routine of the printer.  'p' points
 242  * to the LLC/SNAP header of the packet, 'h->ts' is the timestamp,
 243  * 'h->len' is the length of the packet off the wire, and 'h->caplen'
 244  * is the number of bytes actually captured.
 245  */
 246 u_int
 247 atm_if_print(netdissect_options *ndo,
 248              const struct pcap_pkthdr *h, const u_char *p)
 249 {
 250         u_int caplen = h->caplen;
 251         u_int length = h->len;
 252         uint32_t llchdr;
 253         u_int hdrlen = 0;
 254
 255         ndo->ndo_protocol = "atm_if";
 256         if (caplen < 1) {
 257                 nd_print_trunc(ndo);
 258                 return (caplen);
 259         }
 260
 261         /* Cisco Style NLPID ? */
 262         if (EXTRACT_U_1(p) == LLC_UI) {
 263             if (ndo->ndo_eflag)
 264                 ND_PRINT("CNLPID ");
 265             isoclns_print(ndo, p + 1, length - 1);
 266             return hdrlen;
 267         }
 268
 269         /*
 270          * Must have at least a DSAP, an SSAP, and the first byte of the
 271          * control field.
 272          */
 273         if (caplen < 3) {
 274                 nd_print_trunc(ndo);
 275                 return (caplen);
 276         }
 277
 278         /*
 279          * Extract the presumed LLC header into a variable, for quick
 280          * testing.
 281          * Then check for a header that's neither a header for a SNAP
 282          * packet nor an RFC 2684 routed NLPID-formatted PDU nor
 283          * an 802.2-but-no-SNAP IP packet.
 284          */
 285         llchdr = EXTRACT_BE_U_3(p);
 286         if (llchdr != LLC_UI_HDR(LLCSAP_SNAP) &&
 287             llchdr != LLC_UI_HDR(LLCSAP_ISONS) &&
 288             llchdr != LLC_UI_HDR(LLCSAP_IP)) {
 289                 /*
 290                  * XXX - assume 802.6 MAC header from Fore driver.
 291                  *
 292                  * Unfortunately, the above list doesn't check for
 293                  * all known SAPs, doesn't check for headers where
 294                  * the source and destination SAP aren't the same,
 295                  * and doesn't check for non-UI frames.  It also
 296                  * runs the risk of an 802.6 MAC header that happens
 297                  * to begin with one of those values being
 298                  * incorrectly treated as an 802.2 header.
 299                  *
 300                  * So is that Fore driver still around?  And, if so,
 301                  * is it still putting 802.6 MAC headers on ATM
 302                  * packets?  If so, could it be changed to use a
 303                  * new DLT_IEEE802_6 value if we added it?
 304                  */
 305                 if (caplen < 20) {
 306                         nd_print_trunc(ndo);
 307                         return (caplen);
 308                 }
 309                 if (ndo->ndo_eflag)
 310                         ND_PRINT("%08x%08x %08x%08x ",
 311                                EXTRACT_BE_U_4(p),
 312                                EXTRACT_BE_U_4(p + 4),
 313                                EXTRACT_BE_U_4(p + 8),
 314                                EXTRACT_BE_U_4(p + 12));
 315                 p += 20;
 316                 length -= 20;
 317                 caplen -= 20;
 318                 hdrlen += 20;
 319         }
 320         hdrlen += atm_llc_print(ndo, p, length, caplen);
 321         return (hdrlen);
 322 }
 323
 324 /*
 325  * ATM signalling.
 326  */
 327 static const struct tok msgtype2str[] = {
 328         { CALL_PROCEED,         "Call_proceeding" },
 329         { CONNECT,              "Connect" },
 330         { CONNECT_ACK,          "Connect_ack" },
 331         { SETUP,                "Setup" },
 332         { RELEASE,              "Release" },
 333         { RELEASE_DONE,         "Release_complete" },
 334         { RESTART,              "Restart" },
 335         { RESTART_ACK,          "Restart_ack" },
 336         { STATUS,               "Status" },
 337         { STATUS_ENQ,           "Status_enquiry" },
 338         { ADD_PARTY,            "Add_party" },
 339         { ADD_PARTY_ACK,        "Add_party_ack" },
 340         { ADD_PARTY_REJ,        "Add_party_reject" },
 341         { DROP_PARTY,           "Drop_party" },
 342         { DROP_PARTY_ACK,       "Drop_party_ack" },
 343         { 0,                    NULL }
 344 };
 345
 346 static void
 347 sig_print(netdissect_options *ndo,
 348           const u_char *p)
 349 {
 350         uint32_t call_ref;
 351
 352         ND_TCHECK_1(p + PROTO_POS);
 353         if (EXTRACT_U_1(p + PROTO_POS) == Q2931) {
 354                 /*
 355                  * protocol:Q.2931 for User to Network Interface
 356                  * (UNI 3.1) signalling
 357                  */
 358                 ND_PRINT("Q.2931");
 359                 ND_TCHECK_1(p + MSG_TYPE_POS);
 360                 ND_PRINT(":%s ",
 361                     tok2str(msgtype2str, "msgtype#%u", EXTRACT_U_1(p + MSG_TYPE_POS)));
 362
 363                 /*
 364                  * The call reference comes before the message type,
 365                  * so if we know we have the message type, which we
 366                  * do from the caplen test above, we also know we have
 367                  * the call reference.
 368                  */
 369                 call_ref = EXTRACT_BE_U_3(p + CALL_REF_POS);
 370                 ND_PRINT("CALL_REF:0x%06x", call_ref);
 371         } else {
 372                 /* SSCOP with some unknown protocol atop it */
 373                 ND_PRINT("SSCOP, proto %u ", EXTRACT_U_1(p + PROTO_POS));
 374         }
 375         return;
 376
 377 trunc:
 378         nd_print_trunc(ndo);
 379 }
 380
 381 /*
 382  * Print an ATM PDU (such as an AAL5 PDU).
 383  */
 384 void
 385 atm_print(netdissect_options *ndo,
 386           u_int vpi, u_int vci, u_int traftype, const u_char *p, u_int length,
 387           u_int caplen)
 388 {
 389         ndo->ndo_protocol = "atm";
 390         if (ndo->ndo_eflag)
 391                 ND_PRINT("VPI:%u VCI:%u ", vpi, vci);
 392
 393         if (vpi == 0) {
 394                 switch (vci) {
 395
 396                 case VCI_PPC:
 397                         sig_print(ndo, p);
 398                         return;
 399
 400                 case VCI_BCC:
 401                         ND_PRINT("broadcast sig: ");
 402                         return;
 403
 404                 case VCI_OAMF4SC: /* fall through */
 405                 case VCI_OAMF4EC:
 406                         oam_print(ndo, p, length, ATM_OAM_HEC);
 407                         return;
 408
 409                 case VCI_METAC:
 410                         ND_PRINT("meta: ");
 411                         return;
 412
 413                 case VCI_ILMIC:
 414                         ND_PRINT("ilmi: ");
 415                         snmp_print(ndo, p, length);
 416                         return;
 417                 }
 418         }
 419
 420         switch (traftype) {
 421
 422         case ATM_LLC:
 423         default:
 424                 /*
 425                  * Assumes traffic is LLC if unknown.
 426                  */
 427                 atm_llc_print(ndo, p, length, caplen);
 428                 break;
 429
 430         case ATM_LANE:
 431                 lane_print(ndo, p, length, caplen);
 432                 break;
 433         }
 434 }
 435
 436 struct oam_fm_loopback_t {
 437     nd_uint8_t  loopback_indicator;
 438     nd_uint32_t correlation_tag;
 439     nd_byte     loopback_id[12];
 440     nd_byte     source_id[12];
 441     nd_byte     unused[16];
 442 };
 443
 444 struct oam_fm_ais_rdi_t {
 445     nd_uint8_t  failure_type;
 446     nd_byte     failure_location[16];
 447     nd_byte     unused[28];
 448 };
 449
 450 void
 451 oam_print(netdissect_options *ndo,
 452           const u_char *p, u_int length, u_int hec)
 453 {
 454     uint32_t cell_header;
 455     uint16_t vpi, vci, cksum, cksum_shouldbe, idx;
 456     uint8_t  cell_type, func_type, payload, clp;
 457
 458     union {
 459         const struct oam_fm_loopback_t *oam_fm_loopback;
 460         const struct oam_fm_ais_rdi_t *oam_fm_ais_rdi;
 461     } oam_ptr;
 462
 463     ndo->ndo_protocol = "oam";
 464     ND_TCHECK_1(p + ATM_HDR_LEN_NOHEC + hec);
 465     cell_header = EXTRACT_BE_U_4(p + hec);
 466     cell_type = (EXTRACT_U_1((p + ATM_HDR_LEN_NOHEC + hec)) >> 4) & 0x0f;
 467     func_type = EXTRACT_U_1((p + ATM_HDR_LEN_NOHEC + hec)) & 0x0f;
 468
 469     vpi = (cell_header>>20)&0xff;
 470     vci = (cell_header>>4)&0xffff;
 471     payload = (cell_header>>1)&0x7;
 472     clp = cell_header&0x1;
 473
 474     ND_PRINT("%s, vpi %u, vci %u, payload [ %s ], clp %u, length %u",
 475            tok2str(oam_f_values, "OAM F5", vci),
 476            vpi, vci,
 477            tok2str(atm_pty_values, "Unknown", payload),
 478            clp, length);
 479
 480     if (!ndo->ndo_vflag) {
 481         return;
 482     }
 483
 484     ND_PRINT("\n\tcell-type %s (%u)",
 485            tok2str(oam_celltype_values, "unknown", cell_type),
 486            cell_type);
 487
 488     if (oam_functype_values[cell_type] == NULL)
 489         ND_PRINT(", func-type unknown (%u)", func_type);
 490     else
 491         ND_PRINT(", func-type %s (%u)",
 492                tok2str(oam_functype_values[cell_type],"none",func_type),
 493                func_type);
 494
 495     p += ATM_HDR_LEN_NOHEC + hec;
 496
 497     switch (cell_type << 4 | func_type) {
 498     case (OAM_CELLTYPE_FM << 4 | OAM_FM_FUNCTYPE_LOOPBACK):
 499         oam_ptr.oam_fm_loopback = (const struct oam_fm_loopback_t *)(p + OAM_CELLTYPE_FUNCTYPE_LEN);
 500         ND_TCHECK_SIZE(oam_ptr.oam_fm_loopback);
 501         ND_PRINT("\n\tLoopback-Indicator %s, Correlation-Tag 0x%08x",
 502                tok2str(oam_fm_loopback_indicator_values,
 503                        "Unknown",
 504                        EXTRACT_U_1(oam_ptr.oam_fm_loopback->loopback_indicator) & OAM_FM_LOOPBACK_INDICATOR_MASK),
 505                EXTRACT_BE_U_4(oam_ptr.oam_fm_loopback->correlation_tag));
 506         ND_PRINT("\n\tLocation-ID ");
 507         for (idx = 0; idx < sizeof(oam_ptr.oam_fm_loopback->loopback_id); idx++) {
 508             if (idx % 2) {
 509                 ND_PRINT("%04x ", EXTRACT_BE_U_2(&oam_ptr.oam_fm_loopback->loopback_id[idx]));
 510             }
 511         }
 512         ND_PRINT("\n\tSource-ID   ");
 513         for (idx = 0; idx < sizeof(oam_ptr.oam_fm_loopback->source_id); idx++) {
 514             if (idx % 2) {
 515                 ND_PRINT("%04x ", EXTRACT_BE_U_2(&oam_ptr.oam_fm_loopback->source_id[idx]));
 516             }
 517         }
 518         break;
 519
 520     case (OAM_CELLTYPE_FM << 4 | OAM_FM_FUNCTYPE_AIS):
 521     case (OAM_CELLTYPE_FM << 4 | OAM_FM_FUNCTYPE_RDI):
 522         oam_ptr.oam_fm_ais_rdi = (const struct oam_fm_ais_rdi_t *)(p + OAM_CELLTYPE_FUNCTYPE_LEN);
 523         ND_TCHECK_SIZE(oam_ptr.oam_fm_ais_rdi);
 524         ND_PRINT("\n\tFailure-type 0x%02x", EXTRACT_U_1(oam_ptr.oam_fm_ais_rdi->failure_type));
 525         ND_PRINT("\n\tLocation-ID ");
 526         for (idx = 0; idx < sizeof(oam_ptr.oam_fm_ais_rdi->failure_location); idx++) {
 527             if (idx % 2) {
 528                 ND_PRINT("%04x ", EXTRACT_BE_U_2(&oam_ptr.oam_fm_ais_rdi->failure_location[idx]));
 529             }
 530         }
 531         break;
 532
 533     case (OAM_CELLTYPE_FM << 4 | OAM_FM_FUNCTYPE_CONTCHECK):
 534         /* FIXME */
 535         break;
 536
 537     default:
 538         break;
 539     }
 540
 541     /* crc10 checksum verification */
 542     ND_TCHECK_2(p + OAM_CELLTYPE_FUNCTYPE_LEN + OAM_FUNCTION_SPECIFIC_LEN);
 543     cksum = EXTRACT_BE_U_2(p + OAM_CELLTYPE_FUNCTYPE_LEN + OAM_FUNCTION_SPECIFIC_LEN)
 544         & OAM_CRC10_MASK;
 545     cksum_shouldbe = verify_crc10_cksum(0, p, OAM_PAYLOAD_LEN);
 546
 547     ND_PRINT("\n\tcksum 0x%03x (%scorrect)",
 548            cksum,
 549            cksum_shouldbe == 0 ? "" : "in");
 550
 551     return;
 552
 553 trunc:
 554     nd_print_trunc(ndo);
 555     return;
 556 }