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
750
|
/* Copyright 1998 by the Massachusetts Institute of Technology.
*
* $Id$
*
* Permission to use, copy, modify, and distribute this
* software and its documentation for any purpose and without
* fee is hereby granted, provided that the above copyright
* notice appear in all copies and that both that copyright
* notice and this permission notice appear in supporting
* documentation, and that the name of M.I.T. not be used in
* advertising or publicity pertaining to distribution of the
* software without specific, written prior permission.
* M.I.T. makes no representations about the suitability of
* this software for any purpose. It is provided "as is"
* without express or implied warranty.
*/
#include "ares_setup.h"
#ifdef HAVE_SYS_SOCKET_H
# include <sys/socket.h>
#endif
#ifdef HAVE_NETINET_IN_H
# include <netinet/in.h>
#endif
#ifdef HAVE_ARPA_INET_H
# include <arpa/inet.h>
#endif
#ifdef HAVE_NETDB_H
# include <netdb.h>
#endif
#ifdef HAVE_ARPA_NAMESER_H
# include <arpa/nameser.h>
#else
# include "nameser.h"
#endif
#ifdef HAVE_ARPA_NAMESER_COMPAT_H
# include <arpa/nameser_compat.h>
#endif
#ifdef HAVE_SYS_TIME_H
# include <sys/time.h>
#endif
#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif
#ifdef HAVE_STRINGS_H
# include <strings.h>
#endif
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <errno.h>
#include "ares.h"
#include "ares_dns.h"
#include "inet_ntop.h"
#include "inet_net_pton.h"
#include "ares_getopt.h"
#ifndef HAVE_STRDUP
# include "ares_strdup.h"
# define strdup(ptr) ares_strdup(ptr)
#endif
#ifndef HAVE_STRCASECMP
# include "ares_strcasecmp.h"
# define strcasecmp(p1,p2) ares_strcasecmp(p1,p2)
#endif
#ifndef HAVE_STRNCASECMP
# include "ares_strcasecmp.h"
# define strncasecmp(p1,p2,n) ares_strncasecmp(p1,p2,n)
#endif
#ifdef WATT32
#undef WIN32 /* Redefined in MingW headers */
#endif
/* Mac OS X portability check */
#ifndef T_SRV
#define T_SRV 33 /* server selection */
#endif
/* AIX portability check */
#ifndef T_NAPTR
#define T_NAPTR 35 /* naming authority pointer */
#endif
struct nv {
const char *name;
int value;
};
static const struct nv flags[] = {
{ "usevc", ARES_FLAG_USEVC },
{ "primary", ARES_FLAG_PRIMARY },
{ "igntc", ARES_FLAG_IGNTC },
{ "norecurse", ARES_FLAG_NORECURSE },
{ "stayopen", ARES_FLAG_STAYOPEN },
{ "noaliases", ARES_FLAG_NOALIASES }
};
static const int nflags = sizeof(flags) / sizeof(flags[0]);
static const struct nv classes[] = {
{ "IN", C_IN },
{ "CHAOS", C_CHAOS },
{ "HS", C_HS },
{ "ANY", C_ANY }
};
static const int nclasses = sizeof(classes) / sizeof(classes[0]);
static const struct nv types[] = {
{ "A", T_A },
{ "NS", T_NS },
{ "MD", T_MD },
{ "MF", T_MF },
{ "CNAME", T_CNAME },
{ "SOA", T_SOA },
{ "MB", T_MB },
{ "MG", T_MG },
{ "MR", T_MR },
{ "NULL", T_NULL },
{ "WKS", T_WKS },
{ "PTR", T_PTR },
{ "HINFO", T_HINFO },
{ "MINFO", T_MINFO },
{ "MX", T_MX },
{ "TXT", T_TXT },
{ "RP", T_RP },
{ "AFSDB", T_AFSDB },
{ "X25", T_X25 },
{ "ISDN", T_ISDN },
{ "RT", T_RT },
{ "NSAP", T_NSAP },
{ "NSAP_PTR", T_NSAP_PTR },
{ "SIG", T_SIG },
{ "KEY", T_KEY },
{ "PX", T_PX },
{ "GPOS", T_GPOS },
{ "AAAA", T_AAAA },
{ "LOC", T_LOC },
{ "SRV", T_SRV },
{ "AXFR", T_AXFR },
{ "MAILB", T_MAILB },
{ "MAILA", T_MAILA },
{ "NAPTR", T_NAPTR },
{ "ANY", T_ANY }
};
static const int ntypes = sizeof(types) / sizeof(types[0]);
static const char *opcodes[] = {
"QUERY", "IQUERY", "STATUS", "(reserved)", "NOTIFY",
"(unknown)", "(unknown)", "(unknown)", "(unknown)",
"UPDATEA", "UPDATED", "UPDATEDA", "UPDATEM", "UPDATEMA",
"ZONEINIT", "ZONEREF"
};
struct in_addr inaddr;
static const char *rcodes[] = {
"NOERROR", "FORMERR", "SERVFAIL", "NXDOMAIN", "NOTIMP", "REFUSED",
"(unknown)", "(unknown)", "(unknown)", "(unknown)", "(unknown)",
"(unknown)", "(unknown)", "(unknown)", "(unknown)", "NOCHANGE"
};
static void callback(void *arg, int status, int timeouts,
unsigned char *abuf, int alen);
static const unsigned char *display_question(const unsigned char *aptr,
const unsigned char *abuf,
int alen);
static const unsigned char *display_rr(const unsigned char *aptr,
const unsigned char *abuf, int alen);
static const char *type_name(int type);
static const char *class_name(int dnsclass);
static void usage(void);
int main(int argc, char **argv)
{
ares_channel channel;
int c, i, optmask = ARES_OPT_FLAGS, dnsclass = C_IN, type = T_A;
int status, nfds, count;
struct ares_options options;
struct hostent *hostent;
fd_set read_fds, write_fds;
struct timeval *tvp, tv;
#ifdef USE_WINSOCK
WORD wVersionRequested = MAKEWORD(USE_WINSOCK,USE_WINSOCK);
WSADATA wsaData;
WSAStartup(wVersionRequested, &wsaData);
#endif
status = ares_library_init(ARES_LIB_INIT_ALL);
if (status != ARES_SUCCESS)
{
fprintf(stderr, "ares_library_init: %s\n", ares_strerror(status));
return 1;
}
options.flags = ARES_FLAG_NOCHECKRESP;
options.servers = NULL;
options.nservers = 0;
while ((c = ares_getopt(argc, argv, "df:s:c:t:T:U:")) != -1)
{
switch (c)
{
case 'd':
#ifdef WATT32
dbug_init();
#endif
break;
case 'f':
/* Add a flag. */
for (i = 0; i < nflags; i++)
{
if (strcmp(flags[i].name, optarg) == 0)
break;
}
if (i < nflags)
options.flags |= flags[i].value;
else
usage();
break;
case 's':
/* Add a server, and specify servers in the option mask. */
if (ares_inet_pton(AF_INET, optarg, &inaddr) <= 0)
{
hostent = gethostbyname(optarg);
if (!hostent || hostent->h_addrtype != AF_INET)
{
fprintf(stderr, "adig: server %s not found.\n", optarg);
return 1;
}
memcpy(&inaddr, hostent->h_addr, sizeof(struct in_addr));
}
options.servers = realloc(options.servers, (options.nservers + 1)
* sizeof(struct in_addr));
if (!options.servers)
{
fprintf(stderr, "Out of memory!\n");
return 1;
}
memcpy(&options.servers[options.nservers], &inaddr,
sizeof(struct in_addr));
options.nservers++;
optmask |= ARES_OPT_SERVERS;
break;
case 'c':
/* Set the query class. */
for (i = 0; i < nclasses; i++)
{
if (strcasecmp(classes[i].name, optarg) == 0)
break;
}
if (i < nclasses)
dnsclass = classes[i].value;
else
usage();
break;
case 't':
/* Set the query type. */
for (i = 0; i < ntypes; i++)
{
if (strcasecmp(types[i].name, optarg) == 0)
break;
}
if (i < ntypes)
type = types[i].value;
else
usage();
break;
case 'T':
/* Set the TCP port number. */
if (!ISDIGIT(*optarg))
usage();
options.tcp_port = (unsigned short)strtol(optarg, NULL, 0);
optmask |= ARES_OPT_TCP_PORT;
break;
case 'U':
/* Set the UDP port number. */
if (!ISDIGIT(*optarg))
usage();
options.udp_port = (unsigned short)strtol(optarg, NULL, 0);
optmask |= ARES_OPT_UDP_PORT;
break;
}
}
argc -= optind;
argv += optind;
if (argc == 0)
usage();
status = ares_init_options(&channel, &options, optmask);
if (status != ARES_SUCCESS)
{
fprintf(stderr, "ares_init_options: %s\n",
ares_strerror(status));
return 1;
}
/* Initiate the queries, one per command-line argument. If there is
* only one query to do, supply NULL as the callback argument;
* otherwise, supply the query name as an argument so we can
* distinguish responses for the user when printing them out.
*/
if (argc == 1)
ares_query(channel, *argv, dnsclass, type, callback, (char *) NULL);
else
{
for (; *argv; argv++)
ares_query(channel, *argv, dnsclass, type, callback, *argv);
}
/* Wait for all queries to complete. */
while (1)
{
FD_ZERO(&read_fds);
FD_ZERO(&write_fds);
nfds = ares_fds(channel, &read_fds, &write_fds);
if (nfds == 0)
break;
tvp = ares_timeout(channel, NULL, &tv);
count = select(nfds, &read_fds, &write_fds, NULL, tvp);
if (count < 0 && SOCKERRNO != EINVAL)
{
perror("select");
return 1;
}
ares_process(channel, &read_fds, &write_fds);
}
ares_destroy(channel);
ares_library_cleanup();
#ifdef USE_WINSOCK
WSACleanup();
#endif
return 0;
}
static void callback(void *arg, int status, int timeouts,
unsigned char *abuf, int alen)
{
char *name = (char *) arg;
int id, qr, opcode, aa, tc, rd, ra, rcode;
unsigned int qdcount, ancount, nscount, arcount, i;
const unsigned char *aptr;
(void) timeouts;
/* Display the query name if given. */
if (name)
printf("Answer for query %s:\n", name);
/* Display an error message if there was an error, but only stop if
* we actually didn't get an answer buffer.
*/
if (status != ARES_SUCCESS)
{
printf("%s\n", ares_strerror(status));
if (!abuf)
return;
}
/* Won't happen, but check anyway, for safety. */
if (alen < HFIXEDSZ)
return;
/* Parse the answer header. */
id = DNS_HEADER_QID(abuf);
qr = DNS_HEADER_QR(abuf);
opcode = DNS_HEADER_OPCODE(abuf);
aa = DNS_HEADER_AA(abuf);
tc = DNS_HEADER_TC(abuf);
rd = DNS_HEADER_RD(abuf);
ra = DNS_HEADER_RA(abuf);
rcode = DNS_HEADER_RCODE(abuf);
qdcount = DNS_HEADER_QDCOUNT(abuf);
ancount = DNS_HEADER_ANCOUNT(abuf);
nscount = DNS_HEADER_NSCOUNT(abuf);
arcount = DNS_HEADER_ARCOUNT(abuf);
/* Display the answer header. */
printf("id: %d\n", id);
printf("flags: %s%s%s%s%s\n",
qr ? "qr " : "",
aa ? "aa " : "",
tc ? "tc " : "",
rd ? "rd " : "",
ra ? "ra " : "");
printf("opcode: %s\n", opcodes[opcode]);
printf("rcode: %s\n", rcodes[rcode]);
/* Display the questions. */
printf("Questions:\n");
aptr = abuf + HFIXEDSZ;
for (i = 0; i < qdcount; i++)
{
aptr = display_question(aptr, abuf, alen);
if (aptr == NULL)
return;
}
/* Display the answers. */
printf("Answers:\n");
for (i = 0; i < ancount; i++)
{
aptr = display_rr(aptr, abuf, alen);
if (aptr == NULL)
return;
}
/* Display the NS records. */
printf("NS records:\n");
for (i = 0; i < nscount; i++)
{
aptr = display_rr(aptr, abuf, alen);
if (aptr == NULL)
return;
}
/* Display the additional records. */
printf("Additional records:\n");
for (i = 0; i < arcount; i++)
{
aptr = display_rr(aptr, abuf, alen);
if (aptr == NULL)
return;
}
}
static const unsigned char *display_question(const unsigned char *aptr,
const unsigned char *abuf,
int alen)
{
char *name;
int type, dnsclass, status;
long len;
/* Parse the question name. */
status = ares_expand_name(aptr, abuf, alen, &name, &len);
if (status != ARES_SUCCESS)
return NULL;
aptr += len;
/* Make sure there's enough data after the name for the fixed part
* of the question.
*/
if (aptr + QFIXEDSZ > abuf + alen)
{
ares_free_string(name);
return NULL;
}
/* Parse the question type and class. */
type = DNS_QUESTION_TYPE(aptr);
dnsclass = DNS_QUESTION_CLASS(aptr);
aptr += QFIXEDSZ;
/* Display the question, in a format sort of similar to how we will
* display RRs.
*/
printf("\t%-15s.\t", name);
if (dnsclass != C_IN)
printf("\t%s", class_name(dnsclass));
printf("\t%s\n", type_name(type));
ares_free_string(name);
return aptr;
}
static const unsigned char *display_rr(const unsigned char *aptr,
const unsigned char *abuf, int alen)
{
const unsigned char *p;
int type, dnsclass, ttl, dlen, status;
long len;
char addr[46];
union {
unsigned char * as_uchar;
char * as_char;
} name;
/* Parse the RR name. */
status = ares_expand_name(aptr, abuf, alen, &name.as_char, &len);
if (status != ARES_SUCCESS)
return NULL;
aptr += len;
/* Make sure there is enough data after the RR name for the fixed
* part of the RR.
*/
if (aptr + RRFIXEDSZ > abuf + alen)
{
ares_free_string(name.as_char);
return NULL;
}
/* Parse the fixed part of the RR, and advance to the RR data
* field. */
type = DNS_RR_TYPE(aptr);
dnsclass = DNS_RR_CLASS(aptr);
ttl = DNS_RR_TTL(aptr);
dlen = DNS_RR_LEN(aptr);
aptr += RRFIXEDSZ;
if (aptr + dlen > abuf + alen)
{
ares_free_string(name.as_char);
return NULL;
}
/* Display the RR name, class, and type. */
printf("\t%-15s.\t%d", name.as_char, ttl);
if (dnsclass != C_IN)
printf("\t%s", class_name(dnsclass));
printf("\t%s", type_name(type));
ares_free_string(name.as_char);
/* Display the RR data. Don't touch aptr. */
switch (type)
{
case T_CNAME:
case T_MB:
case T_MD:
case T_MF:
case T_MG:
case T_MR:
case T_NS:
case T_PTR:
/* For these types, the RR data is just a domain name. */
status = ares_expand_name(aptr, abuf, alen, &name.as_char, &len);
if (status != ARES_SUCCESS)
return NULL;
printf("\t%s.", name.as_char);
ares_free_string(name.as_char);
break;
case T_HINFO:
/* The RR data is two length-counted character strings. */
p = aptr;
len = *p;
if (p + len + 1 > aptr + dlen)
return NULL;
status = ares_expand_string(p, abuf, alen, &name.as_uchar, &len);
if (status != ARES_SUCCESS)
return NULL;
printf("\t%s", name.as_char);
ares_free_string(name.as_char);
p += len;
len = *p;
if (p + len + 1 > aptr + dlen)
return NULL;
status = ares_expand_string(p, abuf, alen, &name.as_uchar, &len);
if (status != ARES_SUCCESS)
return NULL;
printf("\t%s", name.as_char);
ares_free_string(name.as_char);
break;
case T_MINFO:
/* The RR data is two domain names. */
p = aptr;
status = ares_expand_name(p, abuf, alen, &name.as_char, &len);
if (status != ARES_SUCCESS)
return NULL;
printf("\t%s.", name.as_char);
ares_free_string(name.as_char);
p += len;
status = ares_expand_name(p, abuf, alen, &name.as_char, &len);
if (status != ARES_SUCCESS)
return NULL;
printf("\t%s.", name.as_char);
ares_free_string(name.as_char);
break;
case T_MX:
/* The RR data is two bytes giving a preference ordering, and
* then a domain name.
*/
if (dlen < 2)
return NULL;
printf("\t%d", DNS__16BIT(aptr));
status = ares_expand_name(aptr + 2, abuf, alen, &name.as_char, &len);
if (status != ARES_SUCCESS)
return NULL;
printf("\t%s.", name.as_char);
ares_free_string(name.as_char);
break;
case T_SOA:
/* The RR data is two domain names and then five four-byte
* numbers giving the serial number and some timeouts.
*/
p = aptr;
status = ares_expand_name(p, abuf, alen, &name.as_char, &len);
if (status != ARES_SUCCESS)
return NULL;
printf("\t%s.\n", name.as_char);
ares_free_string(name.as_char);
p += len;
status = ares_expand_name(p, abuf, alen, &name.as_char, &len);
if (status != ARES_SUCCESS)
return NULL;
printf("\t\t\t\t\t\t%s.\n", name.as_char);
ares_free_string(name.as_char);
p += len;
if (p + 20 > aptr + dlen)
return NULL;
printf("\t\t\t\t\t\t( %lu %lu %lu %lu %lu )",
(unsigned long)DNS__32BIT(p), (unsigned long)DNS__32BIT(p+4),
(unsigned long)DNS__32BIT(p+8), (unsigned long)DNS__32BIT(p+12),
(unsigned long)DNS__32BIT(p+16));
break;
case T_TXT:
/* The RR data is one or more length-counted character
* strings. */
p = aptr;
while (p < aptr + dlen)
{
len = *p;
if (p + len + 1 > aptr + dlen)
return NULL;
status = ares_expand_string(p, abuf, alen, &name.as_uchar, &len);
if (status != ARES_SUCCESS)
return NULL;
printf("\t%s", name.as_char);
ares_free_string(name.as_char);
p += len;
}
break;
case T_A:
/* The RR data is a four-byte Internet address. */
if (dlen != 4)
return NULL;
printf("\t%s", ares_inet_ntop(AF_INET,aptr,addr,sizeof(addr)));
break;
case T_AAAA:
/* The RR data is a 16-byte IPv6 address. */
if (dlen != 16)
return NULL;
printf("\t%s", ares_inet_ntop(AF_INET6,aptr,addr,sizeof(addr)));
break;
case T_WKS:
/* Not implemented yet */
break;
case T_SRV:
/* The RR data is three two-byte numbers representing the
* priority, weight, and port, followed by a domain name.
*/
printf("\t%d", DNS__16BIT(aptr));
printf(" %d", DNS__16BIT(aptr + 2));
printf(" %d", DNS__16BIT(aptr + 4));
status = ares_expand_name(aptr + 6, abuf, alen, &name.as_char, &len);
if (status != ARES_SUCCESS)
return NULL;
printf("\t%s.", name.as_char);
ares_free_string(name.as_char);
break;
case T_NAPTR:
printf("\t%d", DNS__16BIT(aptr)); /* order */
printf(" %d\n", DNS__16BIT(aptr + 2)); /* preference */
p = aptr + 4;
status = ares_expand_string(p, abuf, alen, &name.as_uchar, &len);
if (status != ARES_SUCCESS)
return NULL;
printf("\t\t\t\t\t\t%s\n", name.as_char);
ares_free_string(name.as_char);
p += len;
status = ares_expand_string(p, abuf, alen, &name.as_uchar, &len);
if (status != ARES_SUCCESS)
return NULL;
printf("\t\t\t\t\t\t%s\n", name.as_char);
ares_free_string(name.as_char);
p += len;
status = ares_expand_string(p, abuf, alen, &name.as_uchar, &len);
if (status != ARES_SUCCESS)
return NULL;
printf("\t\t\t\t\t\t%s\n", name.as_char);
ares_free_string(name.as_char);
p += len;
status = ares_expand_string(p, abuf, alen, &name.as_uchar, &len);
if (status != ARES_SUCCESS)
return NULL;
printf("\t\t\t\t\t\t%s", name.as_char);
ares_free_string(name.as_char);
break;
default:
printf("\t[Unknown RR; cannot parse]");
break;
}
printf("\n");
return aptr + dlen;
}
static const char *type_name(int type)
{
int i;
for (i = 0; i < ntypes; i++)
{
if (types[i].value == type)
return types[i].name;
}
return "(unknown)";
}
static const char *class_name(int dnsclass)
{
int i;
for (i = 0; i < nclasses; i++)
{
if (classes[i].value == dnsclass)
return classes[i].name;
}
return "(unknown)";
}
static void usage(void)
{
fprintf(stderr, "usage: adig [-f flag] [-s server] [-c class] "
"[-t type] [-p port] name ...\n");
exit(1);
}
|