xref: /dragonfly/contrib/tcpdump/print-atalk.c (revision 8af44722)
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 
22 /* \summary: AppleTalk printer */
23 
24 #ifdef HAVE_CONFIG_H
25 #include "config.h"
26 #endif
27 
28 #include <netdissect-stdinc.h>
29 
30 #include <stdio.h>
31 #include <string.h>
32 
33 #include "netdissect.h"
34 #include "addrtoname.h"
35 #include "ethertype.h"
36 #include "extract.h"
37 #include "appletalk.h"
38 
39 static const char tstr[] = "[|atalk]";
40 
41 static const struct tok type2str[] = {
42 	{ ddpRTMP,		"rtmp" },
43 	{ ddpRTMPrequest,	"rtmpReq" },
44 	{ ddpECHO,		"echo" },
45 	{ ddpIP,		"IP" },
46 	{ ddpARP,		"ARP" },
47 	{ ddpKLAP,		"KLAP" },
48 	{ 0,			NULL }
49 };
50 
51 struct aarp {
52 	uint16_t	htype, ptype;
53 	uint8_t		halen, palen;
54 	uint16_t	op;
55 	uint8_t		hsaddr[6];
56 	uint8_t		psaddr[4];
57 	uint8_t		hdaddr[6];
58 	uint8_t		pdaddr[4];
59 };
60 
61 static void atp_print(netdissect_options *, const struct atATP *, u_int);
62 static void atp_bitmap_print(netdissect_options *, u_char);
63 static void nbp_print(netdissect_options *, const struct atNBP *, u_int, u_short, u_char, u_char);
64 static const struct atNBPtuple *nbp_tuple_print(netdissect_options *ndo, const struct atNBPtuple *,
65 						const u_char *,
66 						u_short, u_char, u_char);
67 static const struct atNBPtuple *nbp_name_print(netdissect_options *, const struct atNBPtuple *,
68 					       const u_char *);
69 static const char *ataddr_string(netdissect_options *, u_short, u_char);
70 static void ddp_print(netdissect_options *, const u_char *, u_int, int, u_short, u_char, u_char);
71 static const char *ddpskt_string(netdissect_options *, int);
72 
73 /*
74  * Print LLAP packets received on a physical LocalTalk interface.
75  */
76 u_int
77 ltalk_if_print(netdissect_options *ndo,
78                const struct pcap_pkthdr *h, const u_char *p)
79 {
80 	u_int hdrlen;
81 
82 	hdrlen = llap_print(ndo, p, h->len);
83 	if (hdrlen == 0) {
84 		/* Cut short by the snapshot length. */
85 		return (h->caplen);
86 	}
87 	return (hdrlen);
88 }
89 
90 /*
91  * Print AppleTalk LLAP packets.
92  */
93 u_int
94 llap_print(netdissect_options *ndo,
95            register const u_char *bp, u_int length)
96 {
97 	register const struct LAP *lp;
98 	register const struct atDDP *dp;
99 	register const struct atShortDDP *sdp;
100 	u_short snet;
101 	u_int hdrlen;
102 
103 	if (length < sizeof(*lp)) {
104 		ND_PRINT((ndo, " [|llap %u]", length));
105 		return (length);
106 	}
107 	if (!ND_TTEST2(*bp, sizeof(*lp))) {
108 		ND_PRINT((ndo, " [|llap]"));
109 		return (0);	/* cut short by the snapshot length */
110 	}
111 	lp = (const struct LAP *)bp;
112 	bp += sizeof(*lp);
113 	length -= sizeof(*lp);
114 	hdrlen = sizeof(*lp);
115 	switch (lp->type) {
116 
117 	case lapShortDDP:
118 		if (length < ddpSSize) {
119 			ND_PRINT((ndo, " [|sddp %u]", length));
120 			return (length);
121 		}
122 		if (!ND_TTEST2(*bp, ddpSSize)) {
123 			ND_PRINT((ndo, " [|sddp]"));
124 			return (0);	/* cut short by the snapshot length */
125 		}
126 		sdp = (const struct atShortDDP *)bp;
127 		ND_PRINT((ndo, "%s.%s",
128 		    ataddr_string(ndo, 0, lp->src), ddpskt_string(ndo, sdp->srcSkt)));
129 		ND_PRINT((ndo, " > %s.%s:",
130 		    ataddr_string(ndo, 0, lp->dst), ddpskt_string(ndo, sdp->dstSkt)));
131 		bp += ddpSSize;
132 		length -= ddpSSize;
133 		hdrlen += ddpSSize;
134 		ddp_print(ndo, bp, length, sdp->type, 0, lp->src, sdp->srcSkt);
135 		break;
136 
137 	case lapDDP:
138 		if (length < ddpSize) {
139 			ND_PRINT((ndo, " [|ddp %u]", length));
140 			return (length);
141 		}
142 		if (!ND_TTEST2(*bp, ddpSize)) {
143 			ND_PRINT((ndo, " [|ddp]"));
144 			return (0);	/* cut short by the snapshot length */
145 		}
146 		dp = (const struct atDDP *)bp;
147 		snet = EXTRACT_16BITS(&dp->srcNet);
148 		ND_PRINT((ndo, "%s.%s", ataddr_string(ndo, snet, dp->srcNode),
149 		    ddpskt_string(ndo, dp->srcSkt)));
150 		ND_PRINT((ndo, " > %s.%s:",
151 		    ataddr_string(ndo, EXTRACT_16BITS(&dp->dstNet), dp->dstNode),
152 		    ddpskt_string(ndo, dp->dstSkt)));
153 		bp += ddpSize;
154 		length -= ddpSize;
155 		hdrlen += ddpSize;
156 		ddp_print(ndo, bp, length, dp->type, snet, dp->srcNode, dp->srcSkt);
157 		break;
158 
159 #ifdef notdef
160 	case lapKLAP:
161 		klap_print(bp, length);
162 		break;
163 #endif
164 
165 	default:
166 		ND_PRINT((ndo, "%d > %d at-lap#%d %u",
167 		    lp->src, lp->dst, lp->type, length));
168 		break;
169 	}
170 	return (hdrlen);
171 }
172 
173 /*
174  * Print EtherTalk/TokenTalk packets (or FDDITalk, or whatever it's called
175  * when it runs over FDDI; yes, I've seen FDDI captures with AppleTalk
176  * packets in them).
177  */
178 void
179 atalk_print(netdissect_options *ndo,
180             register const u_char *bp, u_int length)
181 {
182 	register const struct atDDP *dp;
183 	u_short snet;
184 
185         if(!ndo->ndo_eflag)
186             ND_PRINT((ndo, "AT "));
187 
188 	if (length < ddpSize) {
189 		ND_PRINT((ndo, " [|ddp %u]", length));
190 		return;
191 	}
192 	if (!ND_TTEST2(*bp, ddpSize)) {
193 		ND_PRINT((ndo, " [|ddp]"));
194 		return;
195 	}
196 	dp = (const struct atDDP *)bp;
197 	snet = EXTRACT_16BITS(&dp->srcNet);
198 	ND_PRINT((ndo, "%s.%s", ataddr_string(ndo, snet, dp->srcNode),
199 	       ddpskt_string(ndo, dp->srcSkt)));
200 	ND_PRINT((ndo, " > %s.%s: ",
201 	       ataddr_string(ndo, EXTRACT_16BITS(&dp->dstNet), dp->dstNode),
202 	       ddpskt_string(ndo, dp->dstSkt)));
203 	bp += ddpSize;
204 	length -= ddpSize;
205 	ddp_print(ndo, bp, length, dp->type, snet, dp->srcNode, dp->srcSkt);
206 }
207 
208 /* XXX should probably pass in the snap header and do checks like arp_print() */
209 void
210 aarp_print(netdissect_options *ndo,
211            register const u_char *bp, u_int length)
212 {
213 	register const struct aarp *ap;
214 
215 #define AT(member) ataddr_string(ndo, (ap->member[1]<<8)|ap->member[2],ap->member[3])
216 
217 	ND_PRINT((ndo, "aarp "));
218 	ap = (const struct aarp *)bp;
219 	if (!ND_TTEST(*ap)) {
220 		/* Just bail if we don't have the whole chunk. */
221 		ND_PRINT((ndo, " [|aarp]"));
222 		return;
223 	}
224 	if (length < sizeof(*ap)) {
225 		ND_PRINT((ndo, " [|aarp %u]", length));
226 		return;
227 	}
228 	if (EXTRACT_16BITS(&ap->htype) == 1 &&
229 	    EXTRACT_16BITS(&ap->ptype) == ETHERTYPE_ATALK &&
230 	    ap->halen == 6 && ap->palen == 4 )
231 		switch (EXTRACT_16BITS(&ap->op)) {
232 
233 		case 1:				/* request */
234 			ND_PRINT((ndo, "who-has %s tell %s", AT(pdaddr), AT(psaddr)));
235 			return;
236 
237 		case 2:				/* response */
238 			ND_PRINT((ndo, "reply %s is-at %s", AT(psaddr), etheraddr_string(ndo, ap->hsaddr)));
239 			return;
240 
241 		case 3:				/* probe (oy!) */
242 			ND_PRINT((ndo, "probe %s tell %s", AT(pdaddr), AT(psaddr)));
243 			return;
244 		}
245 	ND_PRINT((ndo, "len %u op %u htype %u ptype %#x halen %u palen %u",
246 	    length, EXTRACT_16BITS(&ap->op), EXTRACT_16BITS(&ap->htype),
247 	    EXTRACT_16BITS(&ap->ptype), ap->halen, ap->palen));
248 }
249 
250 /*
251  * Print AppleTalk Datagram Delivery Protocol packets.
252  */
253 static void
254 ddp_print(netdissect_options *ndo,
255           register const u_char *bp, register u_int length, register int t,
256           register u_short snet, register u_char snode, u_char skt)
257 {
258 
259 	switch (t) {
260 
261 	case ddpNBP:
262 		nbp_print(ndo, (const struct atNBP *)bp, length, snet, snode, skt);
263 		break;
264 
265 	case ddpATP:
266 		atp_print(ndo, (const struct atATP *)bp, length);
267 		break;
268 
269 	case ddpEIGRP:
270 		eigrp_print(ndo, bp, length);
271 		break;
272 
273 	default:
274 		ND_PRINT((ndo, " at-%s %d", tok2str(type2str, NULL, t), length));
275 		break;
276 	}
277 }
278 
279 static void
280 atp_print(netdissect_options *ndo,
281           register const struct atATP *ap, u_int length)
282 {
283 	char c;
284 	uint32_t data;
285 
286 	if ((const u_char *)(ap + 1) > ndo->ndo_snapend) {
287 		/* Just bail if we don't have the whole chunk. */
288 		ND_PRINT((ndo, "%s", tstr));
289 		return;
290 	}
291 	if (length < sizeof(*ap)) {
292 		ND_PRINT((ndo, " [|atp %u]", length));
293 		return;
294 	}
295 	length -= sizeof(*ap);
296 	switch (ap->control & 0xc0) {
297 
298 	case atpReqCode:
299 		ND_PRINT((ndo, " atp-req%s %d",
300 			     ap->control & atpXO? " " : "*",
301 			     EXTRACT_16BITS(&ap->transID)));
302 
303 		atp_bitmap_print(ndo, ap->bitmap);
304 
305 		if (length != 0)
306 			ND_PRINT((ndo, " [len=%u]", length));
307 
308 		switch (ap->control & (atpEOM|atpSTS)) {
309 		case atpEOM:
310 			ND_PRINT((ndo, " [EOM]"));
311 			break;
312 		case atpSTS:
313 			ND_PRINT((ndo, " [STS]"));
314 			break;
315 		case atpEOM|atpSTS:
316 			ND_PRINT((ndo, " [EOM,STS]"));
317 			break;
318 		}
319 		break;
320 
321 	case atpRspCode:
322 		ND_PRINT((ndo, " atp-resp%s%d:%d (%u)",
323 			     ap->control & atpEOM? "*" : " ",
324 			     EXTRACT_16BITS(&ap->transID), ap->bitmap, length));
325 		switch (ap->control & (atpXO|atpSTS)) {
326 		case atpXO:
327 			ND_PRINT((ndo, " [XO]"));
328 			break;
329 		case atpSTS:
330 			ND_PRINT((ndo, " [STS]"));
331 			break;
332 		case atpXO|atpSTS:
333 			ND_PRINT((ndo, " [XO,STS]"));
334 			break;
335 		}
336 		break;
337 
338 	case atpRelCode:
339 		ND_PRINT((ndo, " atp-rel  %d", EXTRACT_16BITS(&ap->transID)));
340 
341 		atp_bitmap_print(ndo, ap->bitmap);
342 
343 		/* length should be zero */
344 		if (length)
345 			ND_PRINT((ndo, " [len=%u]", length));
346 
347 		/* there shouldn't be any control flags */
348 		if (ap->control & (atpXO|atpEOM|atpSTS)) {
349 			c = '[';
350 			if (ap->control & atpXO) {
351 				ND_PRINT((ndo, "%cXO", c));
352 				c = ',';
353 			}
354 			if (ap->control & atpEOM) {
355 				ND_PRINT((ndo, "%cEOM", c));
356 				c = ',';
357 			}
358 			if (ap->control & atpSTS) {
359 				ND_PRINT((ndo, "%cSTS", c));
360 				c = ',';
361 			}
362 			ND_PRINT((ndo, "]"));
363 		}
364 		break;
365 
366 	default:
367 		ND_PRINT((ndo, " atp-0x%x  %d (%u)", ap->control,
368 			     EXTRACT_16BITS(&ap->transID), length));
369 		break;
370 	}
371 	data = EXTRACT_32BITS(&ap->userData);
372 	if (data != 0)
373 		ND_PRINT((ndo, " 0x%x", data));
374 }
375 
376 static void
377 atp_bitmap_print(netdissect_options *ndo,
378                  register u_char bm)
379 {
380 	register char c;
381 	register int i;
382 
383 	/*
384 	 * The '& 0xff' below is needed for compilers that want to sign
385 	 * extend a u_char, which is the case with the Ultrix compiler.
386 	 * (gcc is smart enough to eliminate it, at least on the Sparc).
387 	 */
388 	if ((bm + 1) & (bm & 0xff)) {
389 		c = '<';
390 		for (i = 0; bm; ++i) {
391 			if (bm & 1) {
392 				ND_PRINT((ndo, "%c%d", c, i));
393 				c = ',';
394 			}
395 			bm >>= 1;
396 		}
397 		ND_PRINT((ndo, ">"));
398 	} else {
399 		for (i = 0; bm; ++i)
400 			bm >>= 1;
401 		if (i > 1)
402 			ND_PRINT((ndo, "<0-%d>", i - 1));
403 		else
404 			ND_PRINT((ndo, "<0>"));
405 	}
406 }
407 
408 static void
409 nbp_print(netdissect_options *ndo,
410           register const struct atNBP *np, u_int length, register u_short snet,
411           register u_char snode, register u_char skt)
412 {
413 	register const struct atNBPtuple *tp =
414 		(const struct atNBPtuple *)((const u_char *)np + nbpHeaderSize);
415 	int i;
416 	const u_char *ep;
417 
418 	if (length < nbpHeaderSize) {
419 		ND_PRINT((ndo, " truncated-nbp %u", length));
420 		return;
421 	}
422 
423 	length -= nbpHeaderSize;
424 	if (length < 8) {
425 		/* must be room for at least one tuple */
426 		ND_PRINT((ndo, " truncated-nbp %u", length + nbpHeaderSize));
427 		return;
428 	}
429 	/* ep points to end of available data */
430 	ep = ndo->ndo_snapend;
431 	if ((const u_char *)tp > ep) {
432 		ND_PRINT((ndo, "%s", tstr));
433 		return;
434 	}
435 	switch (i = np->control & 0xf0) {
436 
437 	case nbpBrRq:
438 	case nbpLkUp:
439 		ND_PRINT((ndo, i == nbpLkUp? " nbp-lkup %d:":" nbp-brRq %d:", np->id));
440 		if ((const u_char *)(tp + 1) > ep) {
441 			ND_PRINT((ndo, "%s", tstr));
442 			return;
443 		}
444 		(void)nbp_name_print(ndo, tp, ep);
445 		/*
446 		 * look for anomalies: the spec says there can only
447 		 * be one tuple, the address must match the source
448 		 * address and the enumerator should be zero.
449 		 */
450 		if ((np->control & 0xf) != 1)
451 			ND_PRINT((ndo, " [ntup=%d]", np->control & 0xf));
452 		if (tp->enumerator)
453 			ND_PRINT((ndo, " [enum=%d]", tp->enumerator));
454 		if (EXTRACT_16BITS(&tp->net) != snet ||
455 		    tp->node != snode || tp->skt != skt)
456 			ND_PRINT((ndo, " [addr=%s.%d]",
457 			    ataddr_string(ndo, EXTRACT_16BITS(&tp->net),
458 			    tp->node), tp->skt));
459 		break;
460 
461 	case nbpLkUpReply:
462 		ND_PRINT((ndo, " nbp-reply %d:", np->id));
463 
464 		/* print each of the tuples in the reply */
465 		for (i = np->control & 0xf; --i >= 0 && tp; )
466 			tp = nbp_tuple_print(ndo, tp, ep, snet, snode, skt);
467 		break;
468 
469 	default:
470 		ND_PRINT((ndo, " nbp-0x%x  %d (%u)", np->control, np->id, length));
471 		break;
472 	}
473 }
474 
475 /* print a counted string */
476 static const char *
477 print_cstring(netdissect_options *ndo,
478               register const char *cp, register const u_char *ep)
479 {
480 	register u_int length;
481 
482 	if (cp >= (const char *)ep) {
483 		ND_PRINT((ndo, "%s", tstr));
484 		return (0);
485 	}
486 	length = *cp++;
487 
488 	/* Spec says string can be at most 32 bytes long */
489 	if (length > 32) {
490 		ND_PRINT((ndo, "[len=%u]", length));
491 		return (0);
492 	}
493 	while ((int)--length >= 0) {
494 		if (cp >= (const char *)ep) {
495 			ND_PRINT((ndo, "%s", tstr));
496 			return (0);
497 		}
498 		ND_PRINT((ndo, "%c", *cp++));
499 	}
500 	return (cp);
501 }
502 
503 static const struct atNBPtuple *
504 nbp_tuple_print(netdissect_options *ndo,
505                 register const struct atNBPtuple *tp, register const u_char *ep,
506                 register u_short snet, register u_char snode, register u_char skt)
507 {
508 	register const struct atNBPtuple *tpn;
509 
510 	if ((const u_char *)(tp + 1) > ep) {
511 		ND_PRINT((ndo, "%s", tstr));
512 		return 0;
513 	}
514 	tpn = nbp_name_print(ndo, tp, ep);
515 
516 	/* if the enumerator isn't 1, print it */
517 	if (tp->enumerator != 1)
518 		ND_PRINT((ndo, "(%d)", tp->enumerator));
519 
520 	/* if the socket doesn't match the src socket, print it */
521 	if (tp->skt != skt)
522 		ND_PRINT((ndo, " %d", tp->skt));
523 
524 	/* if the address doesn't match the src address, it's an anomaly */
525 	if (EXTRACT_16BITS(&tp->net) != snet || tp->node != snode)
526 		ND_PRINT((ndo, " [addr=%s]",
527 		    ataddr_string(ndo, EXTRACT_16BITS(&tp->net), tp->node)));
528 
529 	return (tpn);
530 }
531 
532 static const struct atNBPtuple *
533 nbp_name_print(netdissect_options *ndo,
534                const struct atNBPtuple *tp, register const u_char *ep)
535 {
536 	register const char *cp = (const char *)tp + nbpTupleSize;
537 
538 	ND_PRINT((ndo, " "));
539 
540 	/* Object */
541 	ND_PRINT((ndo, "\""));
542 	if ((cp = print_cstring(ndo, cp, ep)) != NULL) {
543 		/* Type */
544 		ND_PRINT((ndo, ":"));
545 		if ((cp = print_cstring(ndo, cp, ep)) != NULL) {
546 			/* Zone */
547 			ND_PRINT((ndo, "@"));
548 			if ((cp = print_cstring(ndo, cp, ep)) != NULL)
549 				ND_PRINT((ndo, "\""));
550 		}
551 	}
552 	return ((const struct atNBPtuple *)cp);
553 }
554 
555 
556 #define HASHNAMESIZE 4096
557 
558 struct hnamemem {
559 	int addr;
560 	char *name;
561 	struct hnamemem *nxt;
562 };
563 
564 static struct hnamemem hnametable[HASHNAMESIZE];
565 
566 static const char *
567 ataddr_string(netdissect_options *ndo,
568               u_short atnet, u_char athost)
569 {
570 	register struct hnamemem *tp, *tp2;
571 	register int i = (atnet << 8) | athost;
572 	char nambuf[256+1];
573 	static int first = 1;
574 	FILE *fp;
575 
576 	/*
577 	 * if this is the first call, see if there's an AppleTalk
578 	 * number to name map file.
579 	 */
580 	if (first && (first = 0, !ndo->ndo_nflag)
581 	    && (fp = fopen("/etc/atalk.names", "r"))) {
582 		char line[256];
583 		int i1, i2;
584 
585 		while (fgets(line, sizeof(line), fp)) {
586 			if (line[0] == '\n' || line[0] == 0 || line[0] == '#')
587 				continue;
588 			if (sscanf(line, "%d.%d %256s", &i1, &i2, nambuf) == 3)
589 				/* got a hostname. */
590 				i2 |= (i1 << 8);
591 			else if (sscanf(line, "%d %256s", &i1, nambuf) == 2)
592 				/* got a net name */
593 				i2 = (i1 << 8) | 255;
594 			else
595 				continue;
596 
597 			for (tp = &hnametable[i2 & (HASHNAMESIZE-1)];
598 			     tp->nxt; tp = tp->nxt)
599 				;
600 			tp->addr = i2;
601 			tp->nxt = newhnamemem(ndo);
602 			tp->name = strdup(nambuf);
603 			if (tp->name == NULL)
604 				(*ndo->ndo_error)(ndo,
605 						  "ataddr_string: strdup(nambuf)");
606 		}
607 		fclose(fp);
608 	}
609 
610 	for (tp = &hnametable[i & (HASHNAMESIZE-1)]; tp->nxt; tp = tp->nxt)
611 		if (tp->addr == i)
612 			return (tp->name);
613 
614 	/* didn't have the node name -- see if we've got the net name */
615 	i |= 255;
616 	for (tp2 = &hnametable[i & (HASHNAMESIZE-1)]; tp2->nxt; tp2 = tp2->nxt)
617 		if (tp2->addr == i) {
618 			tp->addr = (atnet << 8) | athost;
619 			tp->nxt = newhnamemem(ndo);
620 			(void)snprintf(nambuf, sizeof(nambuf), "%s.%d",
621 			    tp2->name, athost);
622 			tp->name = strdup(nambuf);
623 			if (tp->name == NULL)
624 				(*ndo->ndo_error)(ndo,
625 						  "ataddr_string: strdup(nambuf)");
626 			return (tp->name);
627 		}
628 
629 	tp->addr = (atnet << 8) | athost;
630 	tp->nxt = newhnamemem(ndo);
631 	if (athost != 255)
632 		(void)snprintf(nambuf, sizeof(nambuf), "%d.%d", atnet, athost);
633 	else
634 		(void)snprintf(nambuf, sizeof(nambuf), "%d", atnet);
635 	tp->name = strdup(nambuf);
636 	if (tp->name == NULL)
637 		(*ndo->ndo_error)(ndo, "ataddr_string: strdup(nambuf)");
638 
639 	return (tp->name);
640 }
641 
642 static const struct tok skt2str[] = {
643 	{ rtmpSkt,	"rtmp" },	/* routing table maintenance */
644 	{ nbpSkt,	"nis" },	/* name info socket */
645 	{ echoSkt,	"echo" },	/* AppleTalk echo protocol */
646 	{ zipSkt,	"zip" },	/* zone info protocol */
647 	{ 0,		NULL }
648 };
649 
650 static const char *
651 ddpskt_string(netdissect_options *ndo,
652               register int skt)
653 {
654 	static char buf[8];
655 
656 	if (ndo->ndo_nflag) {
657 		(void)snprintf(buf, sizeof(buf), "%d", skt);
658 		return (buf);
659 	}
660 	return (tok2str(skt2str, "%d", skt));
661 }
662