Fix build on platforms not supporting sockopt SO_PROTOCOL
[exim.git] / test / src / fakens.c
... / ...
CommitLineData
1/*************************************************
2* fakens - A Fake Nameserver Program *
3*************************************************/
4
5/* This program exists to support the testing of DNS handling code in Exim. It
6avoids the need to install special zones in a real nameserver. When Exim is
7running in its (new) test harness, DNS lookups are first passed to this program
8instead of to the real resolver. (With a few exceptions - see the discussion in
9the test suite's README file.) The program is also passed the name of the Exim
10spool directory; it expects to find its "zone files" in dnszones relative to
11exim config_main_directory. Note that there is little checking in this program. The fake
12zone files are assumed to be syntactically valid.
13
14The zones that are handled are found by scanning the dnszones directory. A file
15whose name is of the form db.ip4.x is a zone file for .x.in-addr.arpa; a file
16whose name is of the form db.ip6.x is a zone file for .x.ip6.arpa; a file of
17the form db.anything.else is a zone file for .anything.else. A file of the form
18qualify.x.y specifies the domain that is used to qualify single-component
19names, except for the name "dontqualify".
20
21The arguments to the program are:
22
23 the name of the Exim spool directory
24 the domain name that is being sought
25 the DNS record type that is being sought
26
27The output from the program is written to stdout. It is supposed to be in
28exactly the same format as a traditional nameserver response (see RFC 1035) so
29that Exim can process it as normal. At present, no compression is used.
30Error messages are written to stderr.
31
32The return codes from the program are zero for success, and otherwise the
33values that are set in h_errno after a failing call to the normal resolver:
34
35 1 HOST_NOT_FOUND host not found (authoritative)
36 2 TRY_AGAIN server failure
37 3 NO_RECOVERY non-recoverable error
38 4 NO_DATA valid name, no data of requested type
39
40In a real nameserver, TRY_AGAIN is also used for a non-authoritative not found,
41but it is not used for that here. There is also one extra return code:
42
43 5 PASS_ON requests Exim to call res_search()
44
45This is used for zones that fakens does not recognize. It is also used if a
46line in the zone file contains exactly this:
47
48 PASS ON NOT FOUND
49
50and the domain is not found. It converts the the result to PASS_ON instead of
51HOST_NOT_FOUND.
52
53Any DNS record line in a zone file can be prefixed with "DELAY=" and
54a number of milliseconds (followed by one space).
55
56Any DNS record line can be prefixed with "DNSSEC ";
57if all the records found by a lookup are marked
58as such then the response will have the "AD" bit set.
59
60Any DNS record line can be prefixed with "NXDOMAIN ";
61The record will be ignored (but the prefix set still applied);
62This lets us return a DNSSEC NXDOMAIN (=> HOST_NOT_FOUND).
63
64Any DNS record line can be prefixed with "AA "
65if all the records found by a lookup are marked
66as such then the response will have the "AA" bit set.
67
68Any DNS record line in a zone file can be prefixed with "TTL=" and
69a number of seconds (followed by one space).
70
71*/
72
73#include <ctype.h>
74#include <stdarg.h>
75#include <stdio.h>
76#include <stdlib.h>
77#include <string.h>
78#include <netdb.h>
79#include <errno.h>
80#include <signal.h>
81#include <arpa/nameser.h>
82#include <arpa/inet.h>
83#include <sys/types.h>
84#include <sys/time.h>
85#include <dirent.h>
86#include <unistd.h>
87#ifdef HAVE_SYS_SOCKET_H
88#include <sys/socket.h>
89#endif
90
91#define FALSE 0
92#define TRUE 1
93#define PASS_ON 5
94
95typedef int BOOL;
96typedef unsigned char uschar;
97
98#define CS (char *)
99#define CCS (const char *)
100#define US (unsigned char *)
101
102#define Ustrcat(s,t) strcat(CS(s),CCS(t))
103#define Ustrchr(s,n) US strchr(CCS(s),n)
104#define Ustrcmp(s,t) strcmp(CCS(s),CCS(t))
105#define Ustrcpy(s,t) strcpy(CS(s),CCS(t))
106#define Ustrlen(s) (int)strlen(CCS(s))
107#define Ustrncmp(s,t,n) strncmp(CCS(s),CCS(t),n)
108#define Ustrncpy(s,t,n) strncpy(CS(s),CCS(t),n)
109#define Ustrtok(s,t) (uschar*)strtok(CS(s),CCS(t))
110
111typedef struct zoneitem {
112 uschar *zone;
113 uschar *zonefile;
114} zoneitem;
115
116typedef struct tlist {
117 uschar *name;
118 int value;
119} tlist;
120
121#define DEFAULT_TTL 3600U
122
123/* On some (older?) operating systems, the standard ns_t_xxx definitions are
124not available, and only the older T_xxx ones exist in nameser.h. If ns_t_a is
125not defined, assume we are in this state. A really old system might not even
126know about AAAA and SRV at all. */
127
128#ifndef ns_t_a
129# define ns_t_a T_A
130# define ns_t_ns T_NS
131# define ns_t_cname T_CNAME
132# define ns_t_soa T_SOA
133# define ns_t_ptr T_PTR
134# define ns_t_mx T_MX
135# define ns_t_txt T_TXT
136# define ns_t_aaaa T_AAAA
137# define ns_t_srv T_SRV
138# define ns_t_tlsa T_TLSA
139# ifndef T_AAAA
140# define T_AAAA 28
141# endif
142# ifndef T_SRV
143# define T_SRV 33
144# endif
145# ifndef T_TLSA
146# define T_TLSA 52
147# endif
148#endif
149
150static tlist type_list[] = {
151 { US"A", ns_t_a },
152 { US"NS", ns_t_ns },
153 { US"CNAME", ns_t_cname },
154 { US"SOA", ns_t_soa },
155 { US"PTR", ns_t_ptr },
156 { US"MX", ns_t_mx },
157 { US"TXT", ns_t_txt },
158 { US"AAAA", ns_t_aaaa },
159 { US"SRV", ns_t_srv },
160 { US"TLSA", ns_t_tlsa },
161 { NULL, 0 }
162};
163
164
165
166/*************************************************
167* Get memory and sprintf into it *
168*************************************************/
169
170/* This is used when building a table of zones and their files.
171
172Arguments:
173 format a format string
174 ... arguments
175
176Returns: pointer to formatted string
177*/
178
179static uschar *
180fcopystring(uschar *format, ...)
181{
182uschar *yield;
183char buffer[256];
184va_list ap;
185va_start(ap, format);
186vsprintf(buffer, CS format, ap);
187va_end(ap);
188yield = (uschar *)malloc(Ustrlen(buffer) + 1);
189Ustrcpy(yield, buffer);
190return yield;
191}
192
193
194/*************************************************
195* Pack name into memory *
196*************************************************/
197
198/* This function packs a domain name into memory according to DNS rules. At
199present, it doesn't do any compression.
200
201Arguments:
202 name the name
203 pk where to put it
204
205Returns: the updated value of pk
206*/
207
208static uschar *
209packname(uschar *name, uschar *pk)
210{
211while (*name != 0)
212 {
213 uschar *p = name;
214 while (*p != 0 && *p != '.') p++;
215 *pk++ = (p - name);
216 memmove(pk, name, p - name);
217 pk += p - name;
218 name = (*p == 0)? p : p + 1;
219 }
220*pk++ = 0;
221return pk;
222}
223
224uschar *
225bytefield(uschar ** pp, uschar * pk)
226{
227unsigned value = 0;
228uschar * p = *pp;
229
230while (isdigit(*p)) value = value*10 + *p++ - '0';
231while (isspace(*p)) p++;
232*pp = p;
233*pk++ = value & 255;
234return pk;
235}
236
237uschar *
238shortfield(uschar ** pp, uschar * pk)
239{
240unsigned value = 0;
241uschar * p = *pp;
242
243while (isdigit(*p)) value = value*10 + *p++ - '0';
244while (isspace(*p)) p++;
245*pp = p;
246*pk++ = (value >> 8) & 255;
247*pk++ = value & 255;
248return pk;
249}
250
251uschar *
252longfield(uschar ** pp, uschar * pk)
253{
254unsigned long value = 0;
255uschar * p = *pp;
256
257while (isdigit(*p)) value = value*10 + *p++ - '0';
258while (isspace(*p)) p++;
259*pp = p;
260*pk++ = (value >> 24) & 255;
261*pk++ = (value >> 16) & 255;
262*pk++ = (value >> 8) & 255;
263*pk++ = value & 255;
264return pk;
265}
266
267
268
269/*************************************************/
270
271static void
272milliwait(struct itimerval *itval)
273{
274sigset_t sigmask;
275sigset_t old_sigmask;
276
277if (itval->it_value.tv_usec < 100 && itval->it_value.tv_sec == 0)
278 return;
279(void)sigemptyset(&sigmask); /* Empty mask */
280(void)sigaddset(&sigmask, SIGALRM); /* Add SIGALRM */
281(void)sigprocmask(SIG_BLOCK, &sigmask, &old_sigmask); /* Block SIGALRM */
282(void)setitimer(ITIMER_REAL, itval, NULL); /* Start timer */
283(void)sigfillset(&sigmask); /* All signals */
284(void)sigdelset(&sigmask, SIGALRM); /* Remove SIGALRM */
285(void)sigsuspend(&sigmask); /* Until SIGALRM */
286(void)sigprocmask(SIG_SETMASK, &old_sigmask, NULL); /* Restore mask */
287}
288
289static void
290millisleep(int msec)
291{
292struct itimerval itval;
293itval.it_interval.tv_sec = 0;
294itval.it_interval.tv_usec = 0;
295itval.it_value.tv_sec = msec/1000;
296itval.it_value.tv_usec = (msec % 1000) * 1000;
297milliwait(&itval);
298}
299
300
301/*************************************************
302* Scan file for RRs *
303*************************************************/
304
305/* This function scans an open "zone file" for appropriate records, and adds
306any that are found to the output buffer.
307
308Arguments:
309 f the input FILE
310 zone the current zone name
311 domain the domain we are looking for
312 qtype the type of RR we want
313 qtypelen the length of qtype
314 pkptr points to the output buffer pointer; this is updated
315 countptr points to the record count; this is updated
316 dnssec_p points to the AD flag indicator; this is updated
317 aa_p points to the AA flag indicator; this is updated
318
319Returns: 0 on success, else HOST_NOT_FOUND or NO_DATA or NO_RECOVERY or
320 PASS_ON - the latter if a "PASS ON NOT FOUND" line is seen
321*/
322
323static int
324find_records(FILE *f, uschar *zone, uschar *domain, uschar *qtype,
325 int qtypelen, uschar **pkptr, int *countptr, BOOL * dnssec_p, BOOL * aa_p)
326{
327int yield = HOST_NOT_FOUND;
328int domainlen = Ustrlen(domain);
329BOOL pass_on_not_found = FALSE;
330tlist *typeptr;
331uschar *pk = *pkptr;
332uschar buffer[256];
333uschar rrdomain[256];
334uschar RRdomain[256];
335
336
337/* Decode the required type */
338for (typeptr = type_list; typeptr->name != NULL; typeptr++)
339 { if (Ustrcmp(typeptr->name, qtype) == 0) break; }
340if (typeptr->name == NULL)
341 {
342 fprintf(stderr, "fakens: unknown record type %s\n", qtype);
343 return NO_RECOVERY;
344 }
345
346rrdomain[0] = 0; /* No previous domain */
347(void)fseek(f, 0, SEEK_SET); /* Start again at the beginning */
348
349/* Scan for RRs */
350
351while (fgets(CS buffer, sizeof(buffer), f) != NULL)
352 {
353 uschar *rdlptr;
354 uschar *p, *ep, *pp;
355 BOOL found_cname = FALSE;
356 int i, value;
357 int tvalue = typeptr->value;
358 int qtlen = qtypelen;
359 BOOL rr_sec = FALSE;
360 BOOL rr_aa = FALSE;
361 BOOL rr_ignore = FALSE;
362 int delay = 0;
363 uint ttl = DEFAULT_TTL;
364
365 p = buffer;
366 while (isspace(*p)) p++;
367 if (*p == 0 || *p == ';') continue;
368
369 if (Ustrncmp(p, US"PASS ON NOT FOUND", 17) == 0)
370 {
371 pass_on_not_found = TRUE;
372 continue;
373 }
374
375 ep = buffer + Ustrlen(buffer);
376 while (isspace(ep[-1])) ep--;
377 *ep = 0;
378
379 p = buffer;
380 for (;;)
381 {
382 if (Ustrncmp(p, US"DNSSEC ", 7) == 0) /* tagged as secure */
383 {
384 rr_sec = TRUE;
385 p += 7;
386 }
387 if (Ustrncmp(p, US"NXDOMAIN ", 9) == 0) /* ignore record content */
388 {
389 rr_ignore = TRUE;
390 p += 9;
391 }
392 else if (Ustrncmp(p, US"AA ", 3) == 0) /* tagged as authoritative */
393 {
394 rr_aa = TRUE;
395 p += 3;
396 }
397 else if (Ustrncmp(p, US"DELAY=", 6) == 0) /* delay before response */
398 {
399 for (p += 6; *p >= '0' && *p <= '9'; p++) delay = delay*10 + *p - '0';
400 if (isspace(*p)) p++;
401 }
402 else if (Ustrncmp(p, US"TTL=", 4) == 0) /* TTL for record */
403 {
404 ttl = 0;
405 for (p += 4; *p >= '0' && *p <= '9'; p++) ttl = ttl*10 + *p - '0';
406 if (isspace(*p)) p++;
407 }
408 else
409 break;
410 }
411
412 if (!isspace(*p)) /* new domain name */
413 {
414 uschar *pp = rrdomain;
415 uschar *PP = RRdomain;
416 while (!isspace(*p))
417 {
418 *pp++ = tolower(*p);
419 *PP++ = *p++;
420 }
421 if (pp[-1] != '.')
422 {
423 Ustrcpy(pp, zone);
424 Ustrcpy(PP, zone);
425 }
426 else
427 {
428 pp[-1] = 0;
429 PP[-1] = 0;
430 }
431 } /* else use previous line's domain name */
432
433 /* Compare domain names; first check for a wildcard */
434
435 if (rrdomain[0] == '*')
436 {
437 int restlen = Ustrlen(rrdomain) - 1;
438 if (domainlen > restlen &&
439 Ustrcmp(domain + domainlen - restlen, rrdomain + 1) != 0) continue;
440 }
441
442 /* Not a wildcard RR */
443
444 else if (Ustrcmp(domain, rrdomain) != 0) continue;
445
446 /* The domain matches */
447
448 if (yield == HOST_NOT_FOUND)
449 {
450 yield = NO_DATA;
451 if (dnssec_p) *dnssec_p = TRUE; /* cancelled by first nonsecure rec found */
452 if (aa_p) *aa_p = TRUE; /* cancelled by first non-aa rec found */
453 }
454
455 /* Compare RR types; a CNAME record is always returned */
456
457 while (isspace(*p)) p++;
458
459 if (Ustrncmp(p, "CNAME", 5) == 0)
460 {
461 tvalue = ns_t_cname;
462 qtlen = 5;
463 found_cname = TRUE;
464 }
465 else if (Ustrncmp(p, qtype, qtypelen) != 0 || !isspace(p[qtypelen])) continue;
466
467 /* Found a relevant record */
468 if (delay)
469 millisleep(delay);
470
471 if (dnssec_p && !rr_sec)
472 *dnssec_p = FALSE; /* cancel AD return */
473
474 if (aa_p && !rr_aa)
475 *aa_p = FALSE; /* cancel AA return */
476
477 if (rr_ignore) continue;
478
479 yield = 0;
480 *countptr = *countptr + 1;
481
482 p += qtlen;
483 while (isspace(*p)) p++;
484
485 /* For a wildcard record, use the search name; otherwise use the record's
486 name in its original case because it might contain upper case letters. */
487
488 pk = packname((rrdomain[0] == '*')? domain : RRdomain, pk);
489 *pk++ = (tvalue >> 8) & 255;
490 *pk++ = (tvalue) & 255;
491 *pk++ = 0;
492 *pk++ = 1; /* class = IN */
493
494 *pk++ = (ttl >>24) & 255;
495 *pk++ = (ttl >>16) & 255;
496 *pk++ = (ttl >> 8) & 255;
497 *pk++ = ttl & 255;
498
499 rdlptr = pk; /* remember rdlength field */
500 pk += 2;
501
502 /* The rest of the data depends on the type */
503
504 switch (tvalue)
505 {
506 case ns_t_soa:
507 p = Ustrtok(p, " ");
508 ep = p + Ustrlen(p);
509 if (ep[-1] != '.') sprintf(CS ep, "%s.", zone);
510 pk = packname(p, pk); /* primary ns */
511 p = Ustrtok(NULL, " ");
512 pk = packname(p , pk); /* responsible mailbox */
513 *(p += Ustrlen(p)) = ' ';
514 while (isspace(*p)) p++;
515 pk = longfield(&p, pk); /* serial */
516 pk = longfield(&p, pk); /* refresh */
517 pk = longfield(&p, pk); /* retry */
518 pk = longfield(&p, pk); /* expire */
519 pk = longfield(&p, pk); /* minimum */
520 break;
521
522 case ns_t_a:
523 inet_pton(AF_INET, CCS p, pk); /* FIXME: error checking */
524 pk += 4;
525 break;
526
527 case ns_t_aaaa:
528 inet_pton(AF_INET6, CCS p, pk); /* FIXME: error checking */
529 pk += 16;
530 break;
531
532 case ns_t_mx:
533 pk = shortfield(&p, pk);
534 if (ep[-1] != '.') sprintf(CS ep, "%s.", zone);
535 pk = packname(p, pk);
536 break;
537
538 case ns_t_txt:
539 pp = pk++;
540 if (*p == '"') p++; /* Should always be the case */
541 while (*p != 0 && *p != '"') *pk++ = *p++;
542 *pp = pk - pp - 1;
543 break;
544
545 case ns_t_tlsa:
546 pk = bytefield(&p, pk); /* usage */
547 pk = bytefield(&p, pk); /* selector */
548 pk = bytefield(&p, pk); /* match type */
549 while (isxdigit(*p))
550 {
551 value = toupper(*p) - (isdigit(*p) ? '0' : '7') << 4;
552 if (isxdigit(*++p))
553 {
554 value |= toupper(*p) - (isdigit(*p) ? '0' : '7');
555 p++;
556 }
557 *pk++ = value & 255;
558 }
559
560 break;
561
562 case ns_t_srv:
563 for (i = 0; i < 3; i++)
564 {
565 value = 0;
566 while (isdigit(*p)) value = value*10 + *p++ - '0';
567 while (isspace(*p)) p++;
568 *pk++ = (value >> 8) & 255;
569 *pk++ = value & 255;
570 }
571
572 /* Fall through */
573
574 case ns_t_cname:
575 case ns_t_ns:
576 case ns_t_ptr:
577 if (ep[-1] != '.') sprintf(CS ep, "%s.", zone);
578 pk = packname(p, pk);
579 break;
580 }
581
582 /* Fill in the length, and we are done with this RR */
583
584 rdlptr[0] = ((pk - rdlptr - 2) >> 8) & 255;
585 rdlptr[1] = (pk -rdlptr - 2) & 255;
586 }
587
588*pkptr = pk;
589return (yield == HOST_NOT_FOUND && pass_on_not_found)? PASS_ON : yield;
590}
591
592
593static void
594alarmfn(int sig)
595{
596}
597
598
599/*************************************************
600* Special-purpose domains *
601*************************************************/
602
603static int
604special_manyhome(uschar * packet, uschar * domain)
605{
606uschar *pk = packet + 12;
607uschar *rdlptr;
608int i, j;
609
610memset(packet, 0, 12);
611
612for (i = 104; i <= 111; i++) for (j = 0; j <= 255; j++)
613 {
614 pk = packname(domain, pk);
615 *pk++ = (ns_t_a >> 8) & 255;
616 *pk++ = (ns_t_a) & 255;
617 *pk++ = 0;
618 *pk++ = 1; /* class = IN */
619 pk += 4; /* TTL field; don't care */
620 rdlptr = pk; /* remember rdlength field */
621 pk += 2;
622
623 *pk++ = 10; *pk++ = 250; *pk++ = i; *pk++ = j;
624
625 rdlptr[0] = ((pk - rdlptr - 2) >> 8) & 255;
626 rdlptr[1] = (pk - rdlptr - 2) & 255;
627 }
628
629packet[6] = (2048 >> 8) & 255;
630packet[7] = 2048 & 255;
631packet[10] = 0;
632packet[11] = 0;
633
634(void)fwrite(packet, 1, pk - packet, stdout);
635return 0;
636}
637
638static int
639special_again(uschar * packet, uschar * domain)
640{
641int delay = atoi(CCS domain); /* digits at the start of the name */
642if (delay > 0) sleep(delay);
643return TRY_AGAIN;
644}
645
646
647/*************************************************
648* Entry point and main program *
649*************************************************/
650
651int
652main(int argc, char **argv)
653{
654FILE *f;
655DIR *d;
656int domlen, qtypelen;
657int yield, count;
658int i;
659int zonecount = 0;
660struct dirent *de;
661zoneitem zones[32];
662uschar *qualify = NULL;
663uschar *p, *zone;
664uschar *zonefile = NULL;
665uschar domain[256];
666uschar buffer[256];
667uschar qtype[12];
668uschar packet[2048 * 32 + 32];
669HEADER *header = (HEADER *)packet;
670uschar *pk = packet;
671BOOL dnssec = FALSE;
672BOOL aa = FALSE;
673
674signal(SIGALRM, alarmfn);
675
676if (argc != 4)
677 {
678 fprintf(stderr, "fakens: expected 3 arguments, received %d\n", argc-1);
679 return NO_RECOVERY;
680 }
681
682/* Find the zones */
683
684(void)sprintf(CS buffer, "%s/dnszones", argv[1]);
685
686if (!(d = opendir(CCS buffer)))
687 {
688 fprintf(stderr, "fakens: failed to opendir %s: %s\n", buffer,
689 strerror(errno));
690 return NO_RECOVERY;
691 }
692
693while ((de = readdir(d)))
694 {
695 uschar *name = US de->d_name;
696 if (Ustrncmp(name, "qualify.", 8) == 0)
697 {
698 qualify = fcopystring(US "%s", name + 7);
699 continue;
700 }
701 if (Ustrncmp(name, "db.", 3) != 0) continue;
702 if (Ustrncmp(name + 3, "ip4.", 4) == 0)
703 zones[zonecount].zone = fcopystring(US "%s.in-addr.arpa", name + 6);
704 else if (Ustrncmp(name + 3, "ip6.", 4) == 0)
705 zones[zonecount].zone = fcopystring(US "%s.ip6.arpa", name + 6);
706 else
707 zones[zonecount].zone = fcopystring(US "%s", name + 2);
708 zones[zonecount++].zonefile = fcopystring(US "%s", name);
709 }
710(void)closedir(d);
711
712/* Get the RR type and upper case it, and check that we recognize it. */
713
714Ustrncpy(qtype, argv[3], sizeof(qtype));
715qtypelen = Ustrlen(qtype);
716for (p = qtype; *p != 0; p++) *p = toupper(*p);
717
718/* Find the domain, lower case it, deal with any specials,
719check that it is in a zone that we handle,
720and set up the zone file name. The zone names in the table all start with a
721dot. */
722
723domlen = Ustrlen(argv[2]);
724if (argv[2][domlen-1] == '.') domlen--;
725Ustrncpy(domain, argv[2], domlen);
726domain[domlen] = 0;
727for (i = 0; i < domlen; i++) domain[i] = tolower(domain[i]);
728
729if (Ustrcmp(domain, "manyhome.test.ex") == 0 && Ustrcmp(qtype, "A") == 0)
730 return special_manyhome(packet, domain);
731else if (domlen >= 14 && Ustrcmp(domain + domlen - 14, "test.again.dns") == 0)
732 return special_again(packet, domain);
733else if (domlen >= 13 && Ustrcmp(domain + domlen - 13, "test.fail.dns") == 0)
734 return NO_RECOVERY;
735
736
737if (Ustrchr(domain, '.') == NULL && qualify != NULL &&
738 Ustrcmp(domain, "dontqualify") != 0)
739 {
740 Ustrcat(domain, qualify);
741 domlen += Ustrlen(qualify);
742 }
743
744for (i = 0; i < zonecount; i++)
745 {
746 int zlen;
747 zone = zones[i].zone;
748 zlen = Ustrlen(zone);
749 if (Ustrcmp(domain, zone+1) == 0 || (domlen >= zlen &&
750 Ustrcmp(domain + domlen - zlen, zone) == 0))
751 {
752 zonefile = zones[i].zonefile;
753 break;
754 }
755 }
756
757if (zonefile == NULL)
758 {
759 fprintf(stderr, "fakens: query not in faked zone: domain is: %s\n", domain);
760 return PASS_ON;
761 }
762
763(void)sprintf(CS buffer, "%s/dnszones/%s", argv[1], zonefile);
764
765/* Initialize the start of the response packet. */
766
767memset(packet, 0, 12);
768pk += 12;
769
770/* Open the zone file. */
771
772if (!(f = fopen(CS buffer, "r")))
773 {
774 fprintf(stderr, "fakens: failed to open %s: %s\n", buffer, strerror(errno));
775 return NO_RECOVERY;
776 }
777
778header->qr = 1; /* query */
779header->opcode = QUERY; /* standard query */
780header->tc = 0; /* no truncation */
781
782/* Find the records we want, and add them to the result. */
783
784count = 0;
785yield = find_records(f, zone, domain, qtype, qtypelen, &pk, &count, &dnssec, &aa);
786if (yield == NO_RECOVERY) goto END_OFF;
787header->ancount = htons(count);
788
789/* If the AA bit should be set (as indicated by the AA prefix in the zone file),
790we are expected to return some records in the authoritative section. Bind9: If
791there is data in the answer section, the authoritative section contains the NS
792records, otherwise it contains the SOA record. Mimic that.
793*/
794
795if (strcmp(qtype, "SOA") != 0 && strcmp(qtype, "NS") != 0)
796 if (count)
797 find_records(f, zone, zone[0] == '.' ? zone+1 : zone, US"NS", 2, &pk, &count, NULL, NULL);
798 else
799 find_records(f, zone, zone[0] == '.' ? zone+1 : zone, US"SOA", 3, &pk, &count, NULL, NULL);
800header->nscount = htons(count - ntohs(header->ancount));
801
802/* There is no need to return any additional records because Exim no longer
803(from release 4.61) makes any use of them. */
804header->arcount = 0;
805
806if (dnssec)
807 header->ad = 1;
808
809if (aa)
810 header->aa = 1;
811
812/* Close the zone file, write the result, and return. */
813
814END_OFF:
815(void)fclose(f);
816(void)fwrite(packet, 1, pk - packet, stdout);
817return yield;
818}
819
820/* vi: aw ai sw=2 sts=2 ts=8 et
821*/
822/* End of fakens.c */