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