aboutsummaryrefslogtreecommitdiffstats
path: root/print-domain.c
blob: 9a2b9e85687b633fcb4564ff299cd85f738c358e (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
/*
 * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that: (1) source code distributions
 * retain the above copyright notice and this paragraph in its entirety, (2)
 * distributions including binary code include the above copyright notice and
 * this paragraph in its entirety in the documentation or other materials
 * provided with the distribution, and (3) all advertising materials mentioning
 * features or use of this software display the following acknowledgement:
 * ``This product includes software developed by the University of California,
 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
 * the University nor the names of its contributors may be used to endorse
 * or promote products derived from this software without specific prior
 * written permission.
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */

/* \summary: Domain Name System (DNS) printer */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <netdissect-stdinc.h>

#include "nameser.h"

#include <string.h>

#include "netdissect.h"
#include "addrtoname.h"
#include "addrtostr.h"
#include "extract.h"

static const char *ns_ops[] = {
	"", " inv_q", " stat", " op3", " notify", " update", " op6", " op7",
	" op8", " updateA", " updateD", " updateDA",
	" updateM", " updateMA", " zoneInit", " zoneRef",
};

static const char *ns_resp[] = {
	"", " FormErr", " ServFail", " NXDomain",
	" NotImp", " Refused", " YXDomain", " YXRRSet",
	" NXRRSet", " NotAuth", " NotZone", " Resp11",
	" Resp12", " Resp13", " Resp14", " NoChange",
};

/* skip over a domain name */
static const u_char *
ns_nskip(netdissect_options *ndo,
         register const u_char *cp)
{
	register u_char i;

	if (!ND_TTEST2(*cp, 1))
		return (NULL);
	i = *cp++;
	while (i) {
		if ((i & INDIR_MASK) == INDIR_MASK)
			return (cp + 1);
		if ((i & INDIR_MASK) == EDNS0_MASK) {
			int bitlen, bytelen;

			if ((i & ~INDIR_MASK) != EDNS0_ELT_BITLABEL)
				return(NULL); /* unknown ELT */
			if (!ND_TTEST2(*cp, 1))
				return (NULL);
			if ((bitlen = *cp++) == 0)
				bitlen = 256;
			bytelen = (bitlen + 7) / 8;
			cp += bytelen;
		} else
			cp += i;
		if (!ND_TTEST2(*cp, 1))
			return (NULL);
		i = *cp++;
	}
	return (cp);
}

/* print a <domain-name> */
static const u_char *
blabel_print(netdissect_options *ndo,
             const u_char *cp)
{
	int bitlen, slen, b;
	const u_char *bitp, *lim;
	char tc;

	if (!ND_TTEST2(*cp, 1))
		return(NULL);
	if ((bitlen = *cp) == 0)
		bitlen = 256;
	slen = (bitlen + 3) / 4;
	lim = cp + 1 + slen;

	/* print the bit string as a hex string */
	ND_PRINT((ndo, "\\[x"));
	for (bitp = cp + 1, b = bitlen; bitp < lim && b > 7; b -= 8, bitp++) {
		ND_TCHECK(*bitp);
		ND_PRINT((ndo, "%02x", *bitp));
	}
	if (b > 4) {
		ND_TCHECK(*bitp);
		tc = *bitp++;
		ND_PRINT((ndo, "%02x", tc & (0xff << (8 - b))));
	} else if (b > 0) {
		ND_TCHECK(*bitp);
		tc = *bitp++;
		ND_PRINT((ndo, "%1x", ((tc >> 4) & 0x0f) & (0x0f << (4 - b))));
	}
	ND_PRINT((ndo, "/%d]", bitlen));
	return lim;
trunc:
	ND_PRINT((ndo, ".../%d]", bitlen));
	return NULL;
}

static int
labellen(netdissect_options *ndo,
         const u_char *cp)
{
	register u_int i;

	if (!ND_TTEST2(*cp, 1))
		return(-1);
	i = *cp;
	if ((i & INDIR_MASK) == EDNS0_MASK) {
		int bitlen, elt;
		if ((elt = (i & ~INDIR_MASK)) != EDNS0_ELT_BITLABEL) {
			ND_PRINT((ndo, "<ELT %d>", elt));
			return(-1);
		}
		if (!ND_TTEST2(*(cp + 1), 1))
			return(-1);
		if ((bitlen = *(cp + 1)) == 0)
			bitlen = 256;
		return(((bitlen + 7) / 8) + 1);
	} else
		return(i);
}

const u_char *
ns_nprint(netdissect_options *ndo,
          register const u_char *cp, register const u_char *bp)
{
	register u_int i, l;
	register const u_char *rp = NULL;
	register int compress = 0;
	int elt;
	u_int offset, max_offset;

	if ((l = labellen(ndo, cp)) == (u_int)-1)
		return(NULL);
	if (!ND_TTEST2(*cp, 1))
		return(NULL);
	max_offset = (u_int)(cp - bp);
	if (((i = *cp++) & INDIR_MASK) != INDIR_MASK) {
		compress = 0;
		rp = cp + l;
	}

	if (i != 0)
		while (i && cp < ndo->ndo_snapend) {
			if ((i & INDIR_MASK) == INDIR_MASK) {
				if (!compress) {
					rp = cp + 1;
					compress = 1;
				}
				if (!ND_TTEST2(*cp, 1))
					return(NULL);
				offset = (((i << 8) | *cp) & 0x3fff);
				/*
				 * This must move backwards in the packet.
				 * No RFC explicitly says that, but BIND's
				 * name decompression code requires it,
				 * as a way of preventing infinite loops
				 * and other bad behavior, and it's probably
				 * what was intended (compress by pointing
				 * to domain name suffixes already seen in
				 * the packet).
				 */
				if (offset >= max_offset) {
					ND_PRINT((ndo, "<BAD PTR>"));
					return(NULL);
				}
				max_offset = offset;
				cp = bp + offset;
				if ((l = labellen(ndo, cp)) == (u_int)-1)
					return(NULL);
				if (!ND_TTEST2(*cp, 1))
					return(NULL);
				i = *cp++;
				continue;
			}
			if ((i & INDIR_MASK) == EDNS0_MASK) {
				elt = (i & ~INDIR_MASK);
				switch(elt) {
				case EDNS0_ELT_BITLABEL:
					if (blabel_print(ndo, cp) == NULL)
						return (NULL);
					break;
				default:
					/* unknown ELT */
					ND_PRINT((ndo, "<ELT %d>", elt));
					return(NULL);
				}
			} else {
				if (fn_printn(ndo, cp, l, ndo->ndo_snapend))
					return(NULL);
			}

			cp += l;
			ND_PRINT((ndo, "."));
			if ((l = labellen(ndo, cp)) == (u_int)-1)
				return(NULL);
			if (!ND_TTEST2(*cp, 1))
				return(NULL);
			i = *cp++;
			if (!compress)
				rp += l + 1;
		}
	else
		ND_PRINT((ndo, "."));
	return (rp);
}

/* print a <character-string> */
static const u_char *
ns_cprint(netdissect_options *ndo,
          register const u_char *cp)
{
	register u_int i;

	if (!ND_TTEST2(*cp, 1))
		return (NULL);
	i = *cp++;
	if (fn_printn(ndo, cp, i, ndo->ndo_snapend))
		return (NULL);
	return (cp + i);
}

/* http://www.iana.org/assignments/dns-parameters */
const struct tok ns_type2str[] = {
	{ T_A,		"A" },			/* RFC 1035 */
	{ T_NS,		"NS" },			/* RFC 1035 */
	{ T_MD,		"MD" },			/* RFC 1035 */
	{ T_MF,		"MF" },			/* RFC 1035 */
	{ T_CNAME,	"CNAME" },		/* RFC 1035 */
	{ T_SOA,	"SOA" },		/* RFC 1035 */
	{ T_MB,		"MB" },			/* RFC 1035 */
	{ T_MG,		"MG" },			/* RFC 1035 */
	{ T_MR,		"MR" },			/* RFC 1035 */
	{ T_NULL,	"NULL" },		/* RFC 1035 */
	{ T_WKS,	"WKS" },		/* RFC 1035 */
	{ T_PTR,	"PTR" },		/* RFC 1035 */
	{ T_HINFO,	"HINFO" },		/* RFC 1035 */
	{ T_MINFO,	"MINFO" },		/* RFC 1035 */
	{ T_MX,		"MX" },			/* RFC 1035 */
	{ T_TXT,	"TXT" },		/* RFC 1035 */
	{ T_RP,		"RP" },			/* RFC 1183 */
	{ T_AFSDB,	"AFSDB" },		/* RFC 1183 */
	{ T_X25,	"X25" },		/* RFC 1183 */
	{ T_ISDN,	"ISDN" },		/* RFC 1183 */
	{ T_RT,		"RT" },			/* RFC 1183 */
	{ T_NSAP,	"NSAP" },		/* RFC 1706 */
	{ T_NSAP_PTR,	"NSAP_PTR" },
	{ T_SIG,	"SIG" },		/* RFC 2535 */
	{ T_KEY,	"KEY" },		/* RFC 2535 */
	{ T_PX,		"PX" },			/* RFC 2163 */
	{ T_GPOS,	"GPOS" },		/* RFC 1712 */
	{ T_AAAA,	"AAAA" },		/* RFC 1886 */
	{ T_LOC,	"LOC" },		/* RFC 1876 */
	{ T_NXT,	"NXT" },		/* RFC 2535 */
	{ T_EID,	"EID" },		/* Nimrod */
	{ T_NIMLOC,	"NIMLOC" },		/* Nimrod */
	{ T_SRV,	"SRV" },		/* RFC 2782 */
	{ T_ATMA,	"ATMA" },		/* ATM Forum */
	{ T_NAPTR,	"NAPTR" },		/* RFC 2168, RFC 2915 */
	{ T_KX,		"KX" },			/* RFC 2230 */
	{ T_CERT,	"CERT" },		/* RFC 2538 */
	{ T_A6,		"A6" },			/* RFC 2874 */
	{ T_DNAME,	"DNAME" },		/* RFC 2672 */
	{ T_SINK, 	"SINK" },
	{ T_OPT,	"OPT" },		/* RFC 2671 */
	{ T_APL, 	"APL" },		/* RFC 3123 */
	{ T_DS,		"DS" },			/* RFC 4034 */
	{ T_SSHFP,	"SSHFP" },		/* RFC 4255 */
	{ T_IPSECKEY,	"IPSECKEY" },		/* RFC 4025 */
	{ T_RRSIG, 	"RRSIG" },		/* RFC 4034 */
	{ T_NSEC,	"NSEC" },		/* RFC 4034 */
	{ T_DNSKEY,	"DNSKEY" },		/* RFC 4034 */
	{ T_SPF,	"SPF" },		/* RFC-schlitt-spf-classic-02.txt */
	{ T_UINFO,	"UINFO" },
	{ T_UID,	"UID" },
	{ T_GID,	"GID" },
	{ T_UNSPEC,	"UNSPEC" },
	{ T_UNSPECA,	"UNSPECA" },
	{ T_TKEY,	"TKEY" },		/* RFC 2930 */
	{ T_TSIG,	"TSIG" },		/* RFC 2845 */
	{ T_IXFR,	"IXFR" },		/* RFC 1995 */
	{ T_AXFR,	"AXFR" },		/* RFC 1035 */
	{ T_MAILB,	"MAILB" },		/* RFC 1035 */
	{ T_MAILA,	"MAILA" },		/* RFC 1035 */
	{ T_ANY,	"ANY" },
	{ 0,		NULL }
};

const struct tok ns_class2str[] = {
	{ C_IN,		"IN" },		/* Not used */
	{ C_CHAOS,	"CHAOS" },
	{ C_HS,		"HS" },
	{ C_ANY,	"ANY" },
	{ 0,		NULL }
};

/* print a query */
static const u_char *
ns_qprint(netdissect_options *ndo,
          register const u_char *cp, register const u_char *bp, int is_mdns)
{
	register const u_char *np = cp;
	register u_int i, class;

	cp = ns_nskip(ndo, cp);

	if (cp == NULL || !ND_TTEST2(*cp, 4))
		return(NULL);

	/* print the qtype */
	i = EXTRACT_16BITS(cp);
	cp += 2;
	ND_PRINT((ndo, " %s", tok2str(ns_type2str, "Type%d", i)));
	/* print the qclass (if it's not IN) */
	i = EXTRACT_16BITS(cp);
	cp += 2;
	if (is_mdns)
		class = (i & ~C_QU);
	else
		class = i;
	if (class != C_IN)
		ND_PRINT((ndo, " %s", tok2str(ns_class2str, "(Class %d)", class)));
	if (is_mdns) {
		ND_PRINT((ndo, i & C_QU ? " (QU)" : " (QM)"));
	}

	ND_PRINT((ndo, "? "));
	cp = ns_nprint(ndo, np, bp);
	return(cp ? cp + 4 : NULL);
}

/* print a reply */
static const u_char *
ns_rprint(netdissect_options *ndo,
          register const u_char *cp, register const u_char *bp, int is_mdns)
{
	register u_int i, class, opt_flags = 0;
	register u_short typ, len;
	register const u_char *rp;

	if (ndo->ndo_vflag) {
		ND_PRINT((ndo, " "));
		if ((cp = ns_nprint(ndo, cp, bp)) == NULL)
			return NULL;
	} else
		cp = ns_nskip(ndo, cp);

	if (cp == NULL || !ND_TTEST2(*cp, 10))
		return (ndo->ndo_snapend);

	/* print the type/qtype */
	typ = EXTRACT_16BITS(cp);
	cp += 2;
	/* print the class (if it's not IN and the type isn't OPT) */
	i = EXTRACT_16BITS(cp);
	cp += 2;
	if (is_mdns)
		class = (i & ~C_CACHE_FLUSH);
	else
		class = i;
	if (class != C_IN && typ != T_OPT)
		ND_PRINT((ndo, " %s", tok2str(ns_class2str, "(Class %d)", class)));
	if (is_mdns) {
		if (i & C_CACHE_FLUSH)
			ND_PRINT((ndo, " (Cache flush)"));
	}

	if (typ == T_OPT) {
		/* get opt flags */
		cp += 2;
		opt_flags = EXTRACT_16BITS(cp);
		/* ignore rest of ttl field */
		cp += 2;
	} else if (ndo->ndo_vflag > 2) {
		/* print ttl */
		ND_PRINT((ndo, " ["));
		unsigned_relts_print(ndo, EXTRACT_32BITS(cp));
		ND_PRINT((ndo, "]"));
		cp += 4;
	} else {
		/* ignore ttl */
		cp += 4;
	}

	len = EXTRACT_16BITS(cp);
	cp += 2;

	rp = cp + len;

	ND_PRINT((ndo, " %s", tok2str(ns_type2str, "Type%d", typ)));
	if (rp > ndo->ndo_snapend)
		return(NULL);

	switch (typ) {
	case T_A:
		if (!ND_TTEST2(*cp, sizeof(struct in_addr)))
			return(NULL);
		ND_PRINT((ndo, " %s", intoa(htonl(EXTRACT_32BITS(cp)))));
		break;

	case T_NS:
	case T_CNAME:
	case T_PTR:
#ifdef T_DNAME
	case T_DNAME:
#endif
		ND_PRINT((ndo, " "));
		if (ns_nprint(ndo, cp, bp) == NULL)
			return(NULL);
		break;

	case T_SOA:
		if (!ndo->ndo_vflag)
			break;
		ND_PRINT((ndo, " "));
		if ((cp = ns_nprint(ndo, cp, bp)) == NULL)
			return(NULL);
		ND_PRINT((ndo, " "));
		if ((cp = ns_nprint(ndo, cp, bp)) == NULL)
			return(NULL);
		if (!ND_TTEST2(*cp, 5 * 4))
			return(NULL);
		ND_PRINT((ndo, " %u", EXTRACT_32BITS(cp)));
		cp += 4;
		ND_PRINT((ndo, " %u", EXTRACT_32BITS(cp)));
		cp += 4;
		ND_PRINT((ndo, " %u", EXTRACT_32BITS(cp)));
		cp += 4;
		ND_PRINT((ndo, " %u", EXTRACT_32BITS(cp)));
		cp += 4;
		ND_PRINT((ndo, " %u", EXTRACT_32BITS(cp)));
		cp += 4;
		break;
	case T_MX:
		ND_PRINT((ndo, " "));
		if (!ND_TTEST2(*cp, 2))
			return(NULL);
		if (ns_nprint(ndo, cp + 2, bp) == NULL)
			return(NULL);
		ND_PRINT((ndo, " %d", EXTRACT_16BITS(cp)));
		break;

	case T_TXT:
		while (cp < rp) {
			ND_PRINT((ndo, " \""));
			cp = ns_cprint(ndo, cp);
			if (cp == NULL)
				return(NULL);
			ND_PRINT((ndo, "\""));
		}
		break;

	case T_SRV:
		ND_PRINT((ndo, " "));
		if (!ND_TTEST2(*cp, 6))
			return(NULL);
		if (ns_nprint(ndo, cp + 6, bp) == NULL)
			return(NULL);
		ND_PRINT((ndo, ":%d %d %d", EXTRACT_16BITS(cp + 4),
			EXTRACT_16BITS(cp), EXTRACT_16BITS(cp + 2)));
		break;

	case T_AAAA:
	    {
		char ntop_buf[INET6_ADDRSTRLEN];

		if (!ND_TTEST2(*cp, sizeof(struct in6_addr)))
			return(NULL);
		ND_PRINT((ndo, " %s",
		    addrtostr6(cp, ntop_buf, sizeof(ntop_buf))));

		break;
	    }

	case T_A6:
	    {
		struct in6_addr a;
		int pbit, pbyte;
		char ntop_buf[INET6_ADDRSTRLEN];

		if (!ND_TTEST2(*cp, 1))
			return(NULL);
		pbit = *cp;
		pbyte = (pbit & ~7) / 8;
		if (pbit > 128) {
			ND_PRINT((ndo, " %u(bad plen)", pbit));
			break;
		} else if (pbit < 128) {
			if (!ND_TTEST2(*(cp + 1), sizeof(a) - pbyte))
				return(NULL);
			memset(&a, 0, sizeof(a));
			memcpy(&a.s6_addr[pbyte], cp + 1, sizeof(a) - pbyte);
			ND_PRINT((ndo, " %u %s", pbit,
			    addrtostr6(&a, ntop_buf, sizeof(ntop_buf))));
		}
		if (pbit > 0) {
			ND_PRINT((ndo, " "));
			if (ns_nprint(ndo, cp + 1 + sizeof(a) - pbyte, bp) == NULL)
				return(NULL);
		}
		break;
	    }

	case T_OPT:
		ND_PRINT((ndo, " UDPsize=%u", class));
		if (opt_flags & 0x8000)
			ND_PRINT((ndo, " DO"));
		break;

	case T_UNSPECA:		/* One long string */
		if (!ND_TTEST2(*cp, len))
			return(NULL);
		if (fn_printn(ndo, cp, len, ndo->ndo_snapend))
			return(NULL);
		break;

	case T_TSIG:
	    {
		if (cp + len > ndo->ndo_snapend)
			return(NULL);
		if (!ndo->ndo_vflag)
			break;
		ND_PRINT((ndo, " "));
		if ((cp = ns_nprint(ndo, cp, bp)) == NULL)
			return(NULL);
		cp += 6;
		if (!ND_TTEST2(*cp, 2))
			return(NULL);
		ND_PRINT((ndo, " fudge=%u", EXTRACT_16BITS(cp)));
		cp += 2;
		if (!ND_TTEST2(*cp, 2))
			return(NULL);
		ND_PRINT((ndo, " maclen=%u", EXTRACT_16BITS(cp)));
		cp += 2 + EXTRACT_16BITS(cp);
		if (!ND_TTEST2(*cp, 2))
			return(NULL);
		ND_PRINT((ndo, " origid=%u", EXTRACT_16BITS(cp)));
		cp += 2;
		if (!ND_TTEST2(*cp, 2))
			return(NULL);
		ND_PRINT((ndo, " error=%u", EXTRACT_16BITS(cp)));
		cp += 2;
		if (!ND_TTEST2(*cp, 2))
			return(NULL);
		ND_PRINT((ndo, " otherlen=%u", EXTRACT_16BITS(cp)));
		cp += 2;
	    }
	}
	return (rp);		/* XXX This isn't always right */
}

void
ns_print(netdissect_options *ndo,
         register const u_char *bp, u_int length, int is_mdns)
{
	register const HEADER *np;
	register int qdcount, ancount, nscount, arcount;
	register const u_char *cp;
	uint16_t b2;

	np = (const HEADER *)bp;
	ND_TCHECK(*np);
	/* get the byte-order right */
	qdcount = EXTRACT_16BITS(&np->qdcount);
	ancount = EXTRACT_16BITS(&np->ancount);
	nscount = EXTRACT_16BITS(&np->nscount);
	arcount = EXTRACT_16BITS(&np->arcount);

	if (DNS_QR(np)) {
		/* this is a response */
		ND_PRINT((ndo, "%d%s%s%s%s%s%s",
			EXTRACT_16BITS(&np->id),
			ns_ops[DNS_OPCODE(np)],
			ns_resp[DNS_RCODE(np)],
			DNS_AA(np)? "*" : "",
			DNS_RA(np)? "" : "-",
			DNS_TC(np)? "|" : "",
			DNS_AD(np)? "$" : ""));

		if (qdcount != 1)
			ND_PRINT((ndo, " [%dq]", qdcount));
		/* Print QUESTION section on -vv */
		cp = (const u_char *)(np + 1);
		while (qdcount--) {
			if (qdcount < EXTRACT_16BITS(&np->qdcount) - 1)
				ND_PRINT((ndo, ","));
			if (ndo->ndo_vflag > 1) {
				ND_PRINT((ndo, " q:"));
				if ((cp = ns_qprint(ndo, cp, bp, is_mdns)) == NULL)
					goto trunc;
			} else {
				if ((cp = ns_nskip(ndo, cp)) == NULL)
					goto trunc;
				cp += 4;	/* skip QTYPE and QCLASS */
			}
		}
		ND_PRINT((ndo, " %d/%d/%d", ancount, nscount, arcount));
		if (ancount--) {
			if ((cp = ns_rprint(ndo, cp, bp, is_mdns)) == NULL)
				goto trunc;
			while (cp < ndo->ndo_snapend && ancount--) {
				ND_PRINT((ndo, ","));
				if ((cp = ns_rprint(ndo, cp, bp, is_mdns)) == NULL)
					goto trunc;
			}
		}
		if (ancount > 0)
			goto trunc;
		/* Print NS and AR sections on -vv */
		if (ndo->ndo_vflag > 1) {
			if (cp < ndo->ndo_snapend && nscount--) {
				ND_PRINT((ndo, " ns:"));
				if ((cp = ns_rprint(ndo, cp, bp, is_mdns)) == NULL)
					goto trunc;
				while (cp < ndo->ndo_snapend && nscount--) {
					ND_PRINT((ndo, ","));
					if ((cp = ns_rprint(ndo, cp, bp, is_mdns)) == NULL)
						goto trunc;
				}
			}
			if (nscount > 0)
				goto trunc;
			if (cp < ndo->ndo_snapend && arcount--) {
				ND_PRINT((ndo, " ar:"));
				if ((cp = ns_rprint(ndo, cp, bp, is_mdns)) == NULL)
					goto trunc;
				while (cp < ndo->ndo_snapend && arcount--) {
					ND_PRINT((ndo, ","));
					if ((cp = ns_rprint(ndo, cp, bp, is_mdns)) == NULL)
						goto trunc;
				}
			}
			if (arcount > 0)
				goto trunc;
		}
	}
	else {
		/* this is a request */
		ND_PRINT((ndo, "%d%s%s%s", EXTRACT_16BITS(&np->id), ns_ops[DNS_OPCODE(np)],
		    DNS_RD(np) ? "+" : "",
		    DNS_CD(np) ? "%" : ""));

		/* any weirdness? */
		b2 = EXTRACT_16BITS(((const u_short *)np)+1);
		if (b2 & 0x6cf)
			ND_PRINT((ndo, " [b2&3=0x%x]", b2));

		if (DNS_OPCODE(np) == IQUERY) {
			if (qdcount)
				ND_PRINT((ndo, " [%dq]", qdcount));
			if (ancount != 1)
				ND_PRINT((ndo, " [%da]", ancount));
		}
		else {
			if (ancount)
				ND_PRINT((ndo, " [%da]", ancount));
			if (qdcount != 1)
				ND_PRINT((ndo, " [%dq]", qdcount));
		}
		if (nscount)
			ND_PRINT((ndo, " [%dn]", nscount));
		if (arcount)
			ND_PRINT((ndo, " [%dau]", arcount));

		cp = (const u_char *)(np + 1);
		if (qdcount--) {
			cp = ns_qprint(ndo, cp, (const u_char *)np, is_mdns);
			if (!cp)
				goto trunc;
			while (cp < ndo->ndo_snapend && qdcount--) {
				cp = ns_qprint(ndo, (const u_char *)cp,
					       (const u_char *)np,
					       is_mdns);
				if (!cp)
					goto trunc;
			}
		}
		if (qdcount > 0)
			goto trunc;

		/* Print remaining sections on -vv */
		if (ndo->ndo_vflag > 1) {
			if (ancount--) {
				if ((cp = ns_rprint(ndo, cp, bp, is_mdns)) == NULL)
					goto trunc;
				while (cp < ndo->ndo_snapend && ancount--) {
					ND_PRINT((ndo, ","));
					if ((cp = ns_rprint(ndo, cp, bp, is_mdns)) == NULL)
						goto trunc;
				}
			}
			if (ancount > 0)
				goto trunc;
			if (cp < ndo->ndo_snapend && nscount--) {
				ND_PRINT((ndo, " ns:"));
				if ((cp = ns_rprint(ndo, cp, bp, is_mdns)) == NULL)
					goto trunc;
				while (nscount-- && cp < ndo->ndo_snapend) {
					ND_PRINT((ndo, ","));
					if ((cp = ns_rprint(ndo, cp, bp, is_mdns)) == NULL)
						goto trunc;
				}
			}
			if (nscount > 0)
				goto trunc;
			if (cp < ndo->ndo_snapend && arcount--) {
				ND_PRINT((ndo, " ar:"));
				if ((cp = ns_rprint(ndo, cp, bp, is_mdns)) == NULL)
					goto trunc;
				while (cp < ndo->ndo_snapend && arcount--) {
					ND_PRINT((ndo, ","));
					if ((cp = ns_rprint(ndo, cp, bp, is_mdns)) == NULL)
						goto trunc;
				}
			}
			if (arcount > 0)
				goto trunc;
		}
	}
	ND_PRINT((ndo, " (%d)", length));
	return;

  trunc:
	ND_PRINT((ndo, "[|domain]"));
}