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

   1 /*
   2  * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 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  * Format and print AppleTalk packets.
  22  */
  23
  24 /* \summary: AppleTalk printer */
  25
  26 #ifdef HAVE_CONFIG_H
  27 #include "config.h"
  28 #endif
  29
  30 #include <netdissect-stdinc.h>
  31
  32 #include <stdio.h>
  33 #include <string.h>
  34
  35 #include "netdissect.h"
  36 #include "addrtoname.h"
  37 #include "ethertype.h"
  38 #include "extract.h"
  39 #include "appletalk.h"
  40
  41 static const char tstr[] = "[|atalk]";
  42
  43 static const struct tok type2str[] = {
  44         { ddpRTMP,              "rtmp" },
  45         { ddpRTMPrequest,       "rtmpReq" },
  46         { ddpECHO,              "echo" },
  47         { ddpIP,                "IP" },
  48         { ddpARP,               "ARP" },
  49         { ddpKLAP,              "KLAP" },
  50         { 0,                    NULL }
  51 };
  52
  53 struct aarp {
  54         uint16_t        htype, ptype;
  55         uint8_t         halen, palen;
  56         uint16_t        op;
  57         uint8_t         hsaddr[6];
  58         uint8_t         psaddr[4];
  59         uint8_t         hdaddr[6];
  60         uint8_t         pdaddr[4];
  61 };
  62
  63 static void atp_print(netdissect_options *, const struct atATP *, u_int);
  64 static void atp_bitmap_print(netdissect_options *, u_char);
  65 static void nbp_print(netdissect_options *, const struct atNBP *, u_int, u_short, u_char, u_char);
  66 static const struct atNBPtuple *nbp_tuple_print(netdissect_options *ndo, const struct atNBPtuple *,
  67                                                 const u_char *,
  68                                                 u_short, u_char, u_char);
  69 static const struct atNBPtuple *nbp_name_print(netdissect_options *, const struct atNBPtuple *,
  70                                                const u_char *);
  71 static const char *ataddr_string(netdissect_options *, u_short, u_char);
  72 static void ddp_print(netdissect_options *, const u_char *, u_int, int, u_short, u_char, u_char);
  73 static const char *ddpskt_string(netdissect_options *, int);
  74
  75 /*
  76  * Print LLAP packets received on a physical LocalTalk interface.
  77  */
  78 u_int
  79 ltalk_if_print(netdissect_options *ndo,
  80                const struct pcap_pkthdr *h, const u_char *p)
  81 {
  82         return (llap_print(ndo, p, h->caplen));
  83 }
  84
  85 /*
  86  * Print AppleTalk LLAP packets.
  87  */
  88 u_int
  89 llap_print(netdissect_options *ndo,
  90            register const u_char *bp, u_int length)
  91 {
  92         register const struct LAP *lp;
  93         register const struct atDDP *dp;
  94         register const struct atShortDDP *sdp;
  95         u_short snet;
  96         u_int hdrlen;
  97
  98         if (length < sizeof(*lp)) {
  99                 ND_PRINT((ndo, " [|llap %u]", length));
 100                 return (length);
 101         }
 102         lp = (const struct LAP *)bp;
 103         bp += sizeof(*lp);
 104         length -= sizeof(*lp);
 105         hdrlen = sizeof(*lp);
 106         switch (lp->type) {
 107
 108         case lapShortDDP:
 109                 if (length < ddpSSize) {
 110                         ND_PRINT((ndo, " [|sddp %u]", length));
 111                         return (length);
 112                 }
 113                 sdp = (const struct atShortDDP *)bp;
 114                 ND_PRINT((ndo, "%s.%s",
 115                     ataddr_string(ndo, 0, lp->src), ddpskt_string(ndo, sdp->srcSkt)));
 116                 ND_PRINT((ndo, " > %s.%s:",
 117                     ataddr_string(ndo, 0, lp->dst), ddpskt_string(ndo, sdp->dstSkt)));
 118                 bp += ddpSSize;
 119                 length -= ddpSSize;
 120                 hdrlen += ddpSSize;
 121                 ddp_print(ndo, bp, length, sdp->type, 0, lp->src, sdp->srcSkt);
 122                 break;
 123
 124         case lapDDP:
 125                 if (length < ddpSize) {
 126                         ND_PRINT((ndo, " [|ddp %u]", length));
 127                         return (length);
 128                 }
 129                 dp = (const struct atDDP *)bp;
 130                 snet = EXTRACT_16BITS(&dp->srcNet);
 131                 ND_PRINT((ndo, "%s.%s", ataddr_string(ndo, snet, dp->srcNode),
 132                     ddpskt_string(ndo, dp->srcSkt)));
 133                 ND_PRINT((ndo, " > %s.%s:",
 134                     ataddr_string(ndo, EXTRACT_16BITS(&dp->dstNet), dp->dstNode),
 135                     ddpskt_string(ndo, dp->dstSkt)));
 136                 bp += ddpSize;
 137                 length -= ddpSize;
 138                 hdrlen += ddpSize;
 139                 ddp_print(ndo, bp, length, dp->type, snet, dp->srcNode, dp->srcSkt);
 140                 break;
 141
 142 #ifdef notdef
 143         case lapKLAP:
 144                 klap_print(bp, length);
 145                 break;
 146 #endif
 147
 148         default:
 149                 ND_PRINT((ndo, "%d > %d at-lap#%d %u",
 150                     lp->src, lp->dst, lp->type, length));
 151                 break;
 152         }
 153         return (hdrlen);
 154 }
 155
 156 /*
 157  * Print EtherTalk/TokenTalk packets (or FDDITalk, or whatever it's called
 158  * when it runs over FDDI; yes, I've seen FDDI captures with AppleTalk
 159  * packets in them).
 160  */
 161 void
 162 atalk_print(netdissect_options *ndo,
 163             register const u_char *bp, u_int length)
 164 {
 165         register const struct atDDP *dp;
 166         u_short snet;
 167
 168         if(!ndo->ndo_eflag)
 169             ND_PRINT((ndo, "AT "));
 170
 171         if (length < ddpSize) {
 172                 ND_PRINT((ndo, " [|ddp %u]", length));
 173                 return;
 174         }
 175         dp = (const struct atDDP *)bp;
 176         snet = EXTRACT_16BITS(&dp->srcNet);
 177         ND_PRINT((ndo, "%s.%s", ataddr_string(ndo, snet, dp->srcNode),
 178                ddpskt_string(ndo, dp->srcSkt)));
 179         ND_PRINT((ndo, " > %s.%s: ",
 180                ataddr_string(ndo, EXTRACT_16BITS(&dp->dstNet), dp->dstNode),
 181                ddpskt_string(ndo, dp->dstSkt)));
 182         bp += ddpSize;
 183         length -= ddpSize;
 184         ddp_print(ndo, bp, length, dp->type, snet, dp->srcNode, dp->srcSkt);
 185 }
 186
 187 /* XXX should probably pass in the snap header and do checks like arp_print() */
 188 void
 189 aarp_print(netdissect_options *ndo,
 190            register const u_char *bp, u_int length)
 191 {
 192         register const struct aarp *ap;
 193
 194 #define AT(member) ataddr_string(ndo, (ap->member[1]<<8)|ap->member[2],ap->member[3])
 195
 196         ND_PRINT((ndo, "aarp "));
 197         ap = (const struct aarp *)bp;
 198         if (EXTRACT_16BITS(&ap->htype) == 1 &&
 199             EXTRACT_16BITS(&ap->ptype) == ETHERTYPE_ATALK &&
 200             ap->halen == 6 && ap->palen == 4 )
 201                 switch (EXTRACT_16BITS(&ap->op)) {
 202
 203                 case 1:                         /* request */
 204                         ND_PRINT((ndo, "who-has %s tell %s", AT(pdaddr), AT(psaddr)));
 205                         return;
 206
 207                 case 2:                         /* response */
 208                         ND_PRINT((ndo, "reply %s is-at %s", AT(psaddr), etheraddr_string(ndo, ap->hsaddr)));
 209                         return;
 210
 211                 case 3:                         /* probe (oy!) */
 212                         ND_PRINT((ndo, "probe %s tell %s", AT(pdaddr), AT(psaddr)));
 213                         return;
 214                 }
 215         ND_PRINT((ndo, "len %u op %u htype %u ptype %#x halen %u palen %u",
 216             length, EXTRACT_16BITS(&ap->op), EXTRACT_16BITS(&ap->htype),
 217             EXTRACT_16BITS(&ap->ptype), ap->halen, ap->palen));
 218 }
 219
 220 /*
 221  * Print AppleTalk Datagram Delivery Protocol packets.
 222  */
 223 static void
 224 ddp_print(netdissect_options *ndo,
 225           register const u_char *bp, register u_int length, register int t,
 226           register u_short snet, register u_char snode, u_char skt)
 227 {
 228
 229         switch (t) {
 230
 231         case ddpNBP:
 232                 nbp_print(ndo, (const struct atNBP *)bp, length, snet, snode, skt);
 233                 break;
 234
 235         case ddpATP:
 236                 atp_print(ndo, (const struct atATP *)bp, length);
 237                 break;
 238
 239         case ddpEIGRP:
 240                 eigrp_print(ndo, bp, length);
 241                 break;
 242
 243         default:
 244                 ND_PRINT((ndo, " at-%s %d", tok2str(type2str, NULL, t), length));
 245                 break;
 246         }
 247 }
 248
 249 static void
 250 atp_print(netdissect_options *ndo,
 251           register const struct atATP *ap, u_int length)
 252 {
 253         char c;
 254         uint32_t data;
 255
 256         if ((const u_char *)(ap + 1) > ndo->ndo_snapend) {
 257                 /* Just bail if we don't have the whole chunk. */
 258                 ND_PRINT((ndo, "%s", tstr));
 259                 return;
 260         }
 261         if (length < sizeof(*ap)) {
 262                 ND_PRINT((ndo, " [|atp %u]", length));
 263                 return;
 264         }
 265         length -= sizeof(*ap);
 266         switch (ap->control & 0xc0) {
 267
 268         case atpReqCode:
 269                 ND_PRINT((ndo, " atp-req%s %d",
 270                              ap->control & atpXO? " " : "*",
 271                              EXTRACT_16BITS(&ap->transID)));
 272
 273                 atp_bitmap_print(ndo, ap->bitmap);
 274
 275                 if (length != 0)
 276                         ND_PRINT((ndo, " [len=%u]", length));
 277
 278                 switch (ap->control & (atpEOM|atpSTS)) {
 279                 case atpEOM:
 280                         ND_PRINT((ndo, " [EOM]"));
 281                         break;
 282                 case atpSTS:
 283                         ND_PRINT((ndo, " [STS]"));
 284                         break;
 285                 case atpEOM|atpSTS:
 286                         ND_PRINT((ndo, " [EOM,STS]"));
 287                         break;
 288                 }
 289                 break;
 290
 291         case atpRspCode:
 292                 ND_PRINT((ndo, " atp-resp%s%d:%d (%u)",
 293                              ap->control & atpEOM? "*" : " ",
 294                              EXTRACT_16BITS(&ap->transID), ap->bitmap, length));
 295                 switch (ap->control & (atpXO|atpSTS)) {
 296                 case atpXO:
 297                         ND_PRINT((ndo, " [XO]"));
 298                         break;
 299                 case atpSTS:
 300                         ND_PRINT((ndo, " [STS]"));
 301                         break;
 302                 case atpXO|atpSTS:
 303                         ND_PRINT((ndo, " [XO,STS]"));
 304                         break;
 305                 }
 306                 break;
 307
 308         case atpRelCode:
 309                 ND_PRINT((ndo, " atp-rel  %d", EXTRACT_16BITS(&ap->transID)));
 310
 311                 atp_bitmap_print(ndo, ap->bitmap);
 312
 313                 /* length should be zero */
 314                 if (length)
 315                         ND_PRINT((ndo, " [len=%u]", length));
 316
 317                 /* there shouldn't be any control flags */
 318                 if (ap->control & (atpXO|atpEOM|atpSTS)) {
 319                         c = '[';
 320                         if (ap->control & atpXO) {
 321                                 ND_PRINT((ndo, "%cXO", c));
 322                                 c = ',';
 323                         }
 324                         if (ap->control & atpEOM) {
 325                                 ND_PRINT((ndo, "%cEOM", c));
 326                                 c = ',';
 327                         }
 328                         if (ap->control & atpSTS) {
 329                                 ND_PRINT((ndo, "%cSTS", c));
 330                                 c = ',';
 331                         }
 332                         ND_PRINT((ndo, "]"));
 333                 }
 334                 break;
 335
 336         default:
 337                 ND_PRINT((ndo, " atp-0x%x  %d (%u)", ap->control,
 338                              EXTRACT_16BITS(&ap->transID), length));
 339                 break;
 340         }
 341         data = EXTRACT_32BITS(&ap->userData);
 342         if (data != 0)
 343                 ND_PRINT((ndo, " 0x%x", data));
 344 }
 345
 346 static void
 347 atp_bitmap_print(netdissect_options *ndo,
 348                  register u_char bm)
 349 {
 350         register char c;
 351         register int i;
 352
 353         /*
 354          * The '& 0xff' below is needed for compilers that want to sign
 355          * extend a u_char, which is the case with the Ultrix compiler.
 356          * (gcc is smart enough to eliminate it, at least on the Sparc).
 357          */
 358         if ((bm + 1) & (bm & 0xff)) {
 359                 c = '<';
 360                 for (i = 0; bm; ++i) {
 361                         if (bm & 1) {
 362                                 ND_PRINT((ndo, "%c%d", c, i));
 363                                 c = ',';
 364                         }
 365                         bm >>= 1;
 366                 }
 367                 ND_PRINT((ndo, ">"));
 368         } else {
 369                 for (i = 0; bm; ++i)
 370                         bm >>= 1;
 371                 if (i > 1)
 372                         ND_PRINT((ndo, "<0-%d>", i - 1));
 373                 else
 374                         ND_PRINT((ndo, "<0>"));
 375         }
 376 }
 377
 378 static void
 379 nbp_print(netdissect_options *ndo,
 380           register const struct atNBP *np, u_int length, register u_short snet,
 381           register u_char snode, register u_char skt)
 382 {
 383         register const struct atNBPtuple *tp =
 384                 (const struct atNBPtuple *)((const u_char *)np + nbpHeaderSize);
 385         int i;
 386         const u_char *ep;
 387
 388         if (length < nbpHeaderSize) {
 389                 ND_PRINT((ndo, " truncated-nbp %u", length));
 390                 return;
 391         }
 392
 393         length -= nbpHeaderSize;
 394         if (length < 8) {
 395                 /* must be room for at least one tuple */
 396                 ND_PRINT((ndo, " truncated-nbp %u", length + nbpHeaderSize));
 397                 return;
 398         }
 399         /* ep points to end of available data */
 400         ep = ndo->ndo_snapend;
 401         if ((const u_char *)tp > ep) {
 402                 ND_PRINT((ndo, "%s", tstr));
 403                 return;
 404         }
 405         switch (i = np->control & 0xf0) {
 406
 407         case nbpBrRq:
 408         case nbpLkUp:
 409                 ND_PRINT((ndo, i == nbpLkUp? " nbp-lkup %d:":" nbp-brRq %d:", np->id));
 410                 if ((const u_char *)(tp + 1) > ep) {
 411                         ND_PRINT((ndo, "%s", tstr));
 412                         return;
 413                 }
 414                 (void)nbp_name_print(ndo, tp, ep);
 415                 /*
 416                  * look for anomalies: the spec says there can only
 417                  * be one tuple, the address must match the source
 418                  * address and the enumerator should be zero.
 419                  */
 420                 if ((np->control & 0xf) != 1)
 421                         ND_PRINT((ndo, " [ntup=%d]", np->control & 0xf));
 422                 if (tp->enumerator)
 423                         ND_PRINT((ndo, " [enum=%d]", tp->enumerator));
 424                 if (EXTRACT_16BITS(&tp->net) != snet ||
 425                     tp->node != snode || tp->skt != skt)
 426                         ND_PRINT((ndo, " [addr=%s.%d]",
 427                             ataddr_string(ndo, EXTRACT_16BITS(&tp->net),
 428                             tp->node), tp->skt));
 429                 break;
 430
 431         case nbpLkUpReply:
 432                 ND_PRINT((ndo, " nbp-reply %d:", np->id));
 433
 434                 /* print each of the tuples in the reply */
 435                 for (i = np->control & 0xf; --i >= 0 && tp; )
 436                         tp = nbp_tuple_print(ndo, tp, ep, snet, snode, skt);
 437                 break;
 438
 439         default:
 440                 ND_PRINT((ndo, " nbp-0x%x  %d (%u)", np->control, np->id, length));
 441                 break;
 442         }
 443 }
 444
 445 /* print a counted string */
 446 static const char *
 447 print_cstring(netdissect_options *ndo,
 448               register const char *cp, register const u_char *ep)
 449 {
 450         register u_int length;
 451
 452         if (cp >= (const char *)ep) {
 453                 ND_PRINT((ndo, "%s", tstr));
 454                 return (0);
 455         }
 456         length = *cp++;
 457
 458         /* Spec says string can be at most 32 bytes long */
 459         if (length > 32) {
 460                 ND_PRINT((ndo, "[len=%u]", length));
 461                 return (0);
 462         }
 463         while ((int)--length >= 0) {
 464                 if (cp >= (const char *)ep) {
 465                         ND_PRINT((ndo, "%s", tstr));
 466                         return (0);
 467                 }
 468                 ND_PRINT((ndo, "%c", *cp++));
 469         }
 470         return (cp);
 471 }
 472
 473 static const struct atNBPtuple *
 474 nbp_tuple_print(netdissect_options *ndo,
 475                 register const struct atNBPtuple *tp, register const u_char *ep,
 476                 register u_short snet, register u_char snode, register u_char skt)
 477 {
 478         register const struct atNBPtuple *tpn;
 479
 480         if ((const u_char *)(tp + 1) > ep) {
 481                 ND_PRINT((ndo, "%s", tstr));
 482                 return 0;
 483         }
 484         tpn = nbp_name_print(ndo, tp, ep);
 485
 486         /* if the enumerator isn't 1, print it */
 487         if (tp->enumerator != 1)
 488                 ND_PRINT((ndo, "(%d)", tp->enumerator));
 489
 490         /* if the socket doesn't match the src socket, print it */
 491         if (tp->skt != skt)
 492                 ND_PRINT((ndo, " %d", tp->skt));
 493
 494         /* if the address doesn't match the src address, it's an anomaly */
 495         if (EXTRACT_16BITS(&tp->net) != snet || tp->node != snode)
 496                 ND_PRINT((ndo, " [addr=%s]",
 497                     ataddr_string(ndo, EXTRACT_16BITS(&tp->net), tp->node)));
 498
 499         return (tpn);
 500 }
 501
 502 static const struct atNBPtuple *
 503 nbp_name_print(netdissect_options *ndo,
 504                const struct atNBPtuple *tp, register const u_char *ep)
 505 {
 506         register const char *cp = (const char *)tp + nbpTupleSize;
 507
 508         ND_PRINT((ndo, " "));
 509
 510         /* Object */
 511         ND_PRINT((ndo, "\""));
 512         if ((cp = print_cstring(ndo, cp, ep)) != NULL) {
 513                 /* Type */
 514                 ND_PRINT((ndo, ":"));
 515                 if ((cp = print_cstring(ndo, cp, ep)) != NULL) {
 516                         /* Zone */
 517                         ND_PRINT((ndo, "@"));
 518                         if ((cp = print_cstring(ndo, cp, ep)) != NULL)
 519                                 ND_PRINT((ndo, "\""));
 520                 }
 521         }
 522         return ((const struct atNBPtuple *)cp);
 523 }
 524
 525
 526 #define HASHNAMESIZE 4096
 527
 528 struct hnamemem {
 529         int addr;
 530         char *name;
 531         struct hnamemem *nxt;
 532 };
 533
 534 static struct hnamemem hnametable[HASHNAMESIZE];
 535
 536 static const char *
 537 ataddr_string(netdissect_options *ndo,
 538               u_short atnet, u_char athost)
 539 {
 540         register struct hnamemem *tp, *tp2;
 541         register int i = (atnet << 8) | athost;
 542         char nambuf[256+1];
 543         static int first = 1;
 544         FILE *fp;
 545
 546         /*
 547          * if this is the first call, see if there's an AppleTalk
 548          * number to name map file.
 549          */
 550         if (first && (first = 0, !ndo->ndo_nflag)
 551             && (fp = fopen("/etc/atalk.names", "r"))) {
 552                 char line[256];
 553                 int i1, i2;
 554
 555                 while (fgets(line, sizeof(line), fp)) {
 556                         if (line[0] == '\n' || line[0] == 0 || line[0] == '#')
 557                                 continue;
 558                         if (sscanf(line, "%d.%d %256s", &i1, &i2, nambuf) == 3)
 559                                 /* got a hostname. */
 560                                 i2 |= (i1 << 8);
 561                         else if (sscanf(line, "%d %256s", &i1, nambuf) == 2)
 562                                 /* got a net name */
 563                                 i2 = (i1 << 8) | 255;
 564                         else
 565                                 continue;
 566
 567                         for (tp = &hnametable[i2 & (HASHNAMESIZE-1)];
 568                              tp->nxt; tp = tp->nxt)
 569                                 ;
 570                         tp->addr = i2;
 571                         tp->nxt = newhnamemem(ndo);
 572                         tp->name = strdup(nambuf);
 573                         if (tp->name == NULL)
 574                                 (*ndo->ndo_error)(ndo,
 575                                                   "ataddr_string: strdup(nambuf)");
 576                 }
 577                 fclose(fp);
 578         }
 579
 580         for (tp = &hnametable[i & (HASHNAMESIZE-1)]; tp->nxt; tp = tp->nxt)
 581                 if (tp->addr == i)
 582                         return (tp->name);
 583
 584         /* didn't have the node name -- see if we've got the net name */
 585         i |= 255;
 586         for (tp2 = &hnametable[i & (HASHNAMESIZE-1)]; tp2->nxt; tp2 = tp2->nxt)
 587                 if (tp2->addr == i) {
 588                         tp->addr = (atnet << 8) | athost;
 589                         tp->nxt = newhnamemem(ndo);
 590                         (void)snprintf(nambuf, sizeof(nambuf), "%s.%d",
 591                             tp2->name, athost);
 592                         tp->name = strdup(nambuf);
 593                         if (tp->name == NULL)
 594                                 (*ndo->ndo_error)(ndo,
 595                                                   "ataddr_string: strdup(nambuf)");
 596                         return (tp->name);
 597                 }
 598
 599         tp->addr = (atnet << 8) | athost;
 600         tp->nxt = newhnamemem(ndo);
 601         if (athost != 255)
 602                 (void)snprintf(nambuf, sizeof(nambuf), "%d.%d", atnet, athost);
 603         else
 604                 (void)snprintf(nambuf, sizeof(nambuf), "%d", atnet);
 605         tp->name = strdup(nambuf);
 606         if (tp->name == NULL)
 607                 (*ndo->ndo_error)(ndo, "ataddr_string: strdup(nambuf)");
 608
 609         return (tp->name);
 610 }
 611
 612 static const struct tok skt2str[] = {
 613         { rtmpSkt,      "rtmp" },       /* routing table maintenance */
 614         { nbpSkt,       "nis" },        /* name info socket */
 615         { echoSkt,      "echo" },       /* AppleTalk echo protocol */
 616         { zipSkt,       "zip" },        /* zone info protocol */
 617         { 0,            NULL }
 618 };
 619
 620 static const char *
 621 ddpskt_string(netdissect_options *ndo,
 622               register int skt)
 623 {
 624         static char buf[8];
 625
 626         if (ndo->ndo_nflag) {
 627                 (void)snprintf(buf, sizeof(buf), "%d", skt);
 628                 return (buf);
 629         }
 630         return (tok2str(skt2str, "%d", skt));
 631 }