Commit | Line | Data |
---|---|---|
c55a77db PH |
1 | /************************************************* |
2 | * fakens - A Fake Nameserver Program * | |
3 | *************************************************/ | |
4 | ||
5 | /* This program exists to support the testing of DNS handling code in Exim. It | |
6 | avoids the need to install special zones in a real nameserver. When Exim is | |
7 | running in its (new) test harness, DNS lookups are first passed to this program | |
8 | instead of to the real resolver. (With a few exceptions - see the discussion in | |
9 | the test suite's README file.) The program is also passed the name of the Exim | |
5f3d0983 HSHR |
10 | spool directory; it expects to find its "zone files" in dnszones relative to |
11 | exim config_main_directory. Note that there is little checking in this program. The fake | |
c55a77db PH |
12 | zone files are assumed to be syntactically valid. |
13 | ||
14 | The zones that are handled are found by scanning the dnszones directory. A file | |
15 | whose name is of the form db.ip4.x is a zone file for .x.in-addr.arpa; a file | |
16 | whose name is of the form db.ip6.x is a zone file for .x.ip6.arpa; a file of | |
17 | the form db.anything.else is a zone file for .anything.else. A file of the form | |
18 | qualify.x.y specifies the domain that is used to qualify single-component | |
19 | names, except for the name "dontqualify". | |
20 | ||
21 | The 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 | ||
27 | The output from the program is written to stdout. It is supposed to be in | |
28 | exactly the same format as a traditional namserver response (see RFC 1035) so | |
29 | that Exim can process it as normal. At present, no compression is used. | |
30 | Error messages are written to stderr. | |
31 | ||
32 | The return codes from the program are zero for success, and otherwise the | |
33 | values 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 | ||
40 | In a real nameserver, TRY_AGAIN is also used for a non-authoritative not found, | |
41 | but 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 | ||
45 | This is used for zones that fakens does not recognize. It is also used if a | |
46 | line in the zone file contains exactly this: | |
47 | ||
48 | PASS ON NOT FOUND | |
49 | ||
50 | and the domain is not found. It converts the the result to PASS_ON instead of | |
4d4c2a9b JH |
51 | HOST_NOT_FOUND. |
52 | ||
846430d9 | 53 | Any DNS record line in a zone file can be prefixed with "DELAY=" and |
6aa849d3 | 54 | a number of milliseconds (followed by one space). |
846430d9 | 55 | |
6aa849d3 JH |
56 | Any DNS record line in a zone file can be prefixed with "DNSSEC "; |
57 | if all the records found by a lookup are marked | |
589b3179 HSHR |
58 | as such then the response will have the "AD" bit set. |
59 | ||
6aa849d3 JH |
60 | Any DNS record line in a zone file can be prefixed with "AA " |
61 | if all the records found by a lookup are marked | |
589b3179 HSHR |
62 | as such then the response will have the "AA" bit set. |
63 | ||
64 | */ | |
c55a77db PH |
65 | |
66 | #include <ctype.h> | |
67 | #include <stdarg.h> | |
68 | #include <stdio.h> | |
e265af1f | 69 | #include <stdlib.h> |
c55a77db PH |
70 | #include <string.h> |
71 | #include <netdb.h> | |
72 | #include <errno.h> | |
9d787f10 | 73 | #include <signal.h> |
c55a77db PH |
74 | #include <arpa/nameser.h> |
75 | #include <sys/types.h> | |
846430d9 | 76 | #include <sys/time.h> |
c55a77db PH |
77 | #include <dirent.h> |
78 | ||
79 | #define FALSE 0 | |
80 | #define TRUE 1 | |
81 | #define PASS_ON 5 | |
82 | ||
83 | typedef int BOOL; | |
84 | typedef unsigned char uschar; | |
85 | ||
86 | #define CS (char *) | |
87 | #define CCS (const char *) | |
88 | #define US (unsigned char *) | |
89 | ||
90 | #define Ustrcat(s,t) strcat(CS(s),CCS(t)) | |
91 | #define Ustrchr(s,n) US strchr(CCS(s),n) | |
92 | #define Ustrcmp(s,t) strcmp(CCS(s),CCS(t)) | |
93 | #define Ustrcpy(s,t) strcpy(CS(s),CCS(t)) | |
94 | #define Ustrlen(s) (int)strlen(CCS(s)) | |
95 | #define Ustrncmp(s,t,n) strncmp(CCS(s),CCS(t),n) | |
96 | #define Ustrncpy(s,t,n) strncpy(CS(s),CCS(t),n) | |
97 | ||
c55a77db PH |
98 | typedef struct zoneitem { |
99 | uschar *zone; | |
100 | uschar *zonefile; | |
101 | } zoneitem; | |
102 | ||
103 | typedef struct tlist { | |
104 | uschar *name; | |
105 | int value; | |
106 | } tlist; | |
107 | ||
108 | /* On some (older?) operating systems, the standard ns_t_xxx definitions are | |
109 | not available, and only the older T_xxx ones exist in nameser.h. If ns_t_a is | |
110 | not defined, assume we are in this state. A really old system might not even | |
111 | know about AAAA and SRV at all. */ | |
112 | ||
113 | #ifndef ns_t_a | |
b4161d10 JH |
114 | # define ns_t_a T_A |
115 | # define ns_t_ns T_NS | |
116 | # define ns_t_cname T_CNAME | |
117 | # define ns_t_soa T_SOA | |
118 | # define ns_t_ptr T_PTR | |
119 | # define ns_t_mx T_MX | |
120 | # define ns_t_txt T_TXT | |
121 | # define ns_t_aaaa T_AAAA | |
122 | # define ns_t_srv T_SRV | |
123 | # define ns_t_tlsa T_TLSA | |
124 | # ifndef T_AAAA | |
125 | # define T_AAAA 28 | |
126 | # endif | |
127 | # ifndef T_SRV | |
128 | # define T_SRV 33 | |
129 | # endif | |
130 | # ifndef T_TLSA | |
131 | # define T_TLSA 52 | |
132 | # endif | |
c55a77db PH |
133 | #endif |
134 | ||
135 | static tlist type_list[] = { | |
136 | { US"A", ns_t_a }, | |
137 | { US"NS", ns_t_ns }, | |
138 | { US"CNAME", ns_t_cname }, | |
d2a2c69b | 139 | { US"SOA", ns_t_soa }, |
c55a77db PH |
140 | { US"PTR", ns_t_ptr }, |
141 | { US"MX", ns_t_mx }, | |
142 | { US"TXT", ns_t_txt }, | |
143 | { US"AAAA", ns_t_aaaa }, | |
144 | { US"SRV", ns_t_srv }, | |
b4161d10 | 145 | { US"TLSA", ns_t_tlsa }, |
c55a77db PH |
146 | { NULL, 0 } |
147 | }; | |
148 | ||
149 | ||
150 | ||
151 | /************************************************* | |
152 | * Get memory and sprintf into it * | |
153 | *************************************************/ | |
154 | ||
155 | /* This is used when building a table of zones and their files. | |
156 | ||
157 | Arguments: | |
158 | format a format string | |
159 | ... arguments | |
160 | ||
161 | Returns: pointer to formatted string | |
162 | */ | |
163 | ||
164 | static uschar * | |
165 | fcopystring(uschar *format, ...) | |
166 | { | |
167 | uschar *yield; | |
168 | char buffer[256]; | |
169 | va_list ap; | |
170 | va_start(ap, format); | |
e265af1f | 171 | vsprintf(buffer, CS format, ap); |
c55a77db PH |
172 | va_end(ap); |
173 | yield = (uschar *)malloc(Ustrlen(buffer) + 1); | |
174 | Ustrcpy(yield, buffer); | |
175 | return yield; | |
176 | } | |
177 | ||
178 | ||
179 | /************************************************* | |
180 | * Pack name into memory * | |
181 | *************************************************/ | |
182 | ||
183 | /* This function packs a domain name into memory according to DNS rules. At | |
184 | present, it doesn't do any compression. | |
185 | ||
186 | Arguments: | |
187 | name the name | |
188 | pk where to put it | |
189 | ||
190 | Returns: the updated value of pk | |
191 | */ | |
192 | ||
193 | static uschar * | |
194 | packname(uschar *name, uschar *pk) | |
195 | { | |
196 | while (*name != 0) | |
197 | { | |
198 | uschar *p = name; | |
199 | while (*p != 0 && *p != '.') p++; | |
200 | *pk++ = (p - name); | |
201 | memmove(pk, name, p - name); | |
202 | pk += p - name; | |
203 | name = (*p == 0)? p : p + 1; | |
204 | } | |
205 | *pk++ = 0; | |
206 | return pk; | |
207 | } | |
208 | ||
36b894a6 JH |
209 | uschar * |
210 | bytefield(uschar ** pp, uschar * pk) | |
211 | { | |
212 | unsigned value = 0; | |
213 | uschar * p = *pp; | |
214 | ||
215 | while (isdigit(*p)) value = value*10 + *p++ - '0'; | |
216 | while (isspace(*p)) p++; | |
217 | *pp = p; | |
218 | *pk++ = value & 255; | |
219 | return pk; | |
220 | } | |
221 | ||
b4161d10 JH |
222 | uschar * |
223 | shortfield(uschar ** pp, uschar * pk) | |
224 | { | |
225 | unsigned value = 0; | |
226 | uschar * p = *pp; | |
227 | ||
228 | while (isdigit(*p)) value = value*10 + *p++ - '0'; | |
229 | while (isspace(*p)) p++; | |
230 | *pp = p; | |
231 | *pk++ = (value >> 8) & 255; | |
232 | *pk++ = value & 255; | |
233 | return pk; | |
234 | } | |
235 | ||
d2a2c69b JH |
236 | uschar * |
237 | longfield(uschar ** pp, uschar * pk) | |
238 | { | |
239 | unsigned long value = 0; | |
240 | uschar * p = *pp; | |
241 | ||
242 | while (isdigit(*p)) value = value*10 + *p++ - '0'; | |
243 | while (isspace(*p)) p++; | |
244 | *pp = p; | |
245 | *pk++ = (value >> 24) & 255; | |
246 | *pk++ = (value >> 16) & 255; | |
247 | *pk++ = (value >> 8) & 255; | |
248 | *pk++ = value & 255; | |
249 | return pk; | |
250 | } | |
251 | ||
c55a77db PH |
252 | |
253 | ||
846430d9 JH |
254 | /*************************************************/ |
255 | ||
256 | static void | |
257 | milliwait(struct itimerval *itval) | |
258 | { | |
259 | sigset_t sigmask; | |
260 | sigset_t old_sigmask; | |
261 | ||
262 | if (itval->it_value.tv_usec < 100 && itval->it_value.tv_sec == 0) | |
263 | return; | |
264 | (void)sigemptyset(&sigmask); /* Empty mask */ | |
265 | (void)sigaddset(&sigmask, SIGALRM); /* Add SIGALRM */ | |
266 | (void)sigprocmask(SIG_BLOCK, &sigmask, &old_sigmask); /* Block SIGALRM */ | |
267 | (void)setitimer(ITIMER_REAL, itval, NULL); /* Start timer */ | |
268 | (void)sigfillset(&sigmask); /* All signals */ | |
269 | (void)sigdelset(&sigmask, SIGALRM); /* Remove SIGALRM */ | |
270 | (void)sigsuspend(&sigmask); /* Until SIGALRM */ | |
271 | (void)sigprocmask(SIG_SETMASK, &old_sigmask, NULL); /* Restore mask */ | |
272 | } | |
273 | ||
274 | static void | |
275 | millisleep(int msec) | |
276 | { | |
277 | struct itimerval itval; | |
278 | itval.it_interval.tv_sec = 0; | |
279 | itval.it_interval.tv_usec = 0; | |
280 | itval.it_value.tv_sec = msec/1000; | |
281 | itval.it_value.tv_usec = (msec % 1000) * 1000; | |
282 | milliwait(&itval); | |
283 | } | |
284 | ||
285 | ||
c55a77db PH |
286 | /************************************************* |
287 | * Scan file for RRs * | |
288 | *************************************************/ | |
289 | ||
290 | /* This function scans an open "zone file" for appropriate records, and adds | |
291 | any that are found to the output buffer. | |
292 | ||
293 | Arguments: | |
294 | f the input FILE | |
295 | zone the current zone name | |
296 | domain the domain we are looking for | |
297 | qtype the type of RR we want | |
298 | qtypelen the length of qtype | |
299 | pkptr points to the output buffer pointer; this is updated | |
300 | countptr points to the record count; this is updated | |
589b3179 HSHR |
301 | dnssec points to the AD flag indicator; this updated |
302 | aa points to the AA flag indicator; this updated | |
c55a77db PH |
303 | |
304 | Returns: 0 on success, else HOST_NOT_FOUND or NO_DATA or NO_RECOVERY or | |
305 | PASS_ON - the latter if a "PASS ON NOT FOUND" line is seen | |
306 | */ | |
307 | ||
308 | static int | |
309 | find_records(FILE *f, uschar *zone, uschar *domain, uschar *qtype, | |
589b3179 | 310 | int qtypelen, uschar **pkptr, int *countptr, BOOL * dnssec, BOOL * aa) |
c55a77db PH |
311 | { |
312 | int yield = HOST_NOT_FOUND; | |
c55a77db PH |
313 | int domainlen = Ustrlen(domain); |
314 | BOOL pass_on_not_found = FALSE; | |
315 | tlist *typeptr; | |
316 | uschar *pk = *pkptr; | |
317 | uschar buffer[256]; | |
318 | uschar rrdomain[256]; | |
75e0e026 | 319 | uschar RRdomain[256]; |
c55a77db PH |
320 | |
321 | /* Decode the required type */ | |
322 | ||
323 | for (typeptr = type_list; typeptr->name != NULL; typeptr++) | |
324 | { if (Ustrcmp(typeptr->name, qtype) == 0) break; } | |
325 | if (typeptr->name == NULL) | |
326 | { | |
327 | fprintf(stderr, "fakens: unknown record type %s\n", qtype); | |
328 | return NO_RECOVERY; | |
329 | } | |
330 | ||
331 | rrdomain[0] = 0; /* No previous domain */ | |
332 | (void)fseek(f, 0, SEEK_SET); /* Start again at the beginning */ | |
333 | ||
b4161d10 | 334 | *dnssec = TRUE; /* cancelled by first nonsecure rec found */ |
589b3179 | 335 | *aa = TRUE; /* cancelled by first non-authoritive record */ |
4d4c2a9b | 336 | |
c55a77db PH |
337 | /* Scan for RRs */ |
338 | ||
339 | while (fgets(CS buffer, sizeof(buffer), f) != NULL) | |
340 | { | |
341 | uschar *rdlptr; | |
342 | uschar *p, *ep, *pp; | |
343 | BOOL found_cname = FALSE; | |
d2a2c69b | 344 | int i, value; |
c55a77db PH |
345 | int tvalue = typeptr->value; |
346 | int qtlen = qtypelen; | |
4d4c2a9b | 347 | BOOL rr_sec = FALSE; |
589b3179 | 348 | BOOL rr_aa = FALSE; |
846430d9 | 349 | int delay = 0; |
c55a77db PH |
350 | |
351 | p = buffer; | |
352 | while (isspace(*p)) p++; | |
353 | if (*p == 0 || *p == ';') continue; | |
354 | ||
4d4c2a9b | 355 | if (Ustrncmp(p, US"PASS ON NOT FOUND", 17) == 0) |
c55a77db PH |
356 | { |
357 | pass_on_not_found = TRUE; | |
358 | continue; | |
359 | } | |
360 | ||
361 | ep = buffer + Ustrlen(buffer); | |
362 | while (isspace(ep[-1])) ep--; | |
363 | *ep = 0; | |
364 | ||
365 | p = buffer; | |
846430d9 | 366 | for (;;) |
1fb7660f JH |
367 | { |
368 | if (Ustrncmp(p, US"DNSSEC ", 7) == 0) /* tagged as secure */ | |
369 | { | |
370 | rr_sec = TRUE; | |
371 | p += 7; | |
372 | } | |
589b3179 HSHR |
373 | else if (Ustrncmp(p, US"AA ", 3) == 0) /* tagged as authoritive */ |
374 | { | |
375 | rr_aa = TRUE; | |
376 | p += 3; | |
377 | } | |
1fb7660f JH |
378 | else if (Ustrncmp(p, US"DELAY=", 6) == 0) /* delay before response */ |
379 | { | |
380 | for (p += 6; *p >= '0' && *p <= '9'; p++) delay = delay*10 + *p - '0'; | |
6aa849d3 | 381 | if (isspace(*p)) p++; |
1fb7660f JH |
382 | } |
383 | else | |
384 | break; | |
385 | } | |
4d4c2a9b | 386 | |
6aa849d3 | 387 | if (!isspace(*p)) /* new domain name */ |
c55a77db PH |
388 | { |
389 | uschar *pp = rrdomain; | |
75e0e026 PH |
390 | uschar *PP = RRdomain; |
391 | while (!isspace(*p)) | |
392 | { | |
393 | *pp++ = tolower(*p); | |
394 | *PP++ = *p++; | |
395 | } | |
396 | if (pp[-1] != '.') | |
397 | { | |
398 | Ustrcpy(pp, zone); | |
399 | Ustrcpy(PP, zone); | |
400 | } | |
401 | else | |
402 | { | |
403 | pp[-1] = 0; | |
404 | PP[-1] = 0; | |
405 | } | |
6aa849d3 | 406 | } /* else use previous line's domain name */ |
c55a77db PH |
407 | |
408 | /* Compare domain names; first check for a wildcard */ | |
409 | ||
410 | if (rrdomain[0] == '*') | |
411 | { | |
412 | int restlen = Ustrlen(rrdomain) - 1; | |
413 | if (domainlen > restlen && | |
414 | Ustrcmp(domain + domainlen - restlen, rrdomain + 1) != 0) continue; | |
415 | } | |
416 | ||
417 | /* Not a wildcard RR */ | |
418 | ||
419 | else if (Ustrcmp(domain, rrdomain) != 0) continue; | |
420 | ||
421 | /* The domain matches */ | |
422 | ||
423 | if (yield == HOST_NOT_FOUND) yield = NO_DATA; | |
424 | ||
425 | /* Compare RR types; a CNAME record is always returned */ | |
426 | ||
427 | while (isspace(*p)) p++; | |
428 | ||
429 | if (Ustrncmp(p, "CNAME", 5) == 0) | |
430 | { | |
431 | tvalue = ns_t_cname; | |
432 | qtlen = 5; | |
433 | found_cname = TRUE; | |
434 | } | |
435 | else if (Ustrncmp(p, qtype, qtypelen) != 0 || !isspace(p[qtypelen])) continue; | |
436 | ||
437 | /* Found a relevant record */ | |
438 | ||
846430d9 JH |
439 | if (delay) |
440 | millisleep(delay); | |
441 | ||
4d4c2a9b JH |
442 | if (!rr_sec) |
443 | *dnssec = FALSE; /* cancel AD return */ | |
444 | ||
589b3179 HSHR |
445 | if (!rr_aa) |
446 | *aa = FALSE; /* cancel AA return */ | |
447 | ||
c55a77db PH |
448 | yield = 0; |
449 | *countptr = *countptr + 1; | |
450 | ||
451 | p += qtlen; | |
452 | while (isspace(*p)) p++; | |
453 | ||
75e0e026 PH |
454 | /* For a wildcard record, use the search name; otherwise use the record's |
455 | name in its original case because it might contain upper case letters. */ | |
456 | ||
457 | pk = packname((rrdomain[0] == '*')? domain : RRdomain, pk); | |
c55a77db PH |
458 | *pk++ = (tvalue >> 8) & 255; |
459 | *pk++ = (tvalue) & 255; | |
460 | *pk++ = 0; | |
461 | *pk++ = 1; /* class = IN */ | |
462 | ||
463 | pk += 4; /* TTL field; don't care */ | |
464 | ||
465 | rdlptr = pk; /* remember rdlength field */ | |
466 | pk += 2; | |
467 | ||
468 | /* The rest of the data depends on the type */ | |
469 | ||
470 | switch (tvalue) | |
471 | { | |
d2a2c69b JH |
472 | case ns_t_soa: |
473 | p = strtok(p, " "); | |
474 | ep = p + strlen(p); | |
475 | if (ep[-1] != '.') sprintf(CS ep, "%s.", zone); | |
476 | pk = packname(p, pk); /* primary ns */ | |
477 | p = strtok(NULL, " "); | |
478 | pk = packname(p , pk); /* responsible mailbox */ | |
479 | *(p += strlen(p)) = ' '; | |
480 | while (isspace(*p)) p++; | |
481 | pk = longfield(&p, pk); /* serial */ | |
482 | pk = longfield(&p, pk); /* refresh */ | |
483 | pk = longfield(&p, pk); /* retry */ | |
484 | pk = longfield(&p, pk); /* expire */ | |
485 | pk = longfield(&p, pk); /* minimum */ | |
486 | break; | |
c55a77db PH |
487 | |
488 | case ns_t_a: | |
d2a2c69b JH |
489 | for (i = 0; i < 4; i++) |
490 | { | |
491 | value = 0; | |
492 | while (isdigit(*p)) value = value*10 + *p++ - '0'; | |
493 | *pk++ = value; | |
494 | p++; | |
495 | } | |
496 | break; | |
c55a77db PH |
497 | |
498 | /* The only occurrence of a double colon is for ::1 */ | |
499 | case ns_t_aaaa: | |
d2a2c69b JH |
500 | if (Ustrcmp(p, "::1") == 0) |
501 | { | |
502 | memset(pk, 0, 15); | |
503 | pk += 15; | |
504 | *pk++ = 1; | |
505 | } | |
506 | else for (i = 0; i < 8; i++) | |
507 | { | |
508 | value = 0; | |
509 | while (isxdigit(*p)) | |
510 | { | |
511 | value = value * 16 + toupper(*p) - (isdigit(*p)? '0' : '7'); | |
512 | p++; | |
513 | } | |
514 | *pk++ = (value >> 8) & 255; | |
515 | *pk++ = value & 255; | |
516 | p++; | |
517 | } | |
518 | break; | |
c55a77db PH |
519 | |
520 | case ns_t_mx: | |
d2a2c69b JH |
521 | pk = shortfield(&p, pk); |
522 | if (ep[-1] != '.') sprintf(CS ep, "%s.", zone); | |
523 | pk = packname(p, pk); | |
524 | break; | |
c55a77db PH |
525 | |
526 | case ns_t_txt: | |
d2a2c69b JH |
527 | pp = pk++; |
528 | if (*p == '"') p++; /* Should always be the case */ | |
529 | while (*p != 0 && *p != '"') *pk++ = *p++; | |
530 | *pp = pk - pp - 1; | |
531 | break; | |
c55a77db | 532 | |
b4161d10 | 533 | case ns_t_tlsa: |
d2a2c69b JH |
534 | pk = bytefield(&p, pk); /* usage */ |
535 | pk = bytefield(&p, pk); /* selector */ | |
536 | pk = bytefield(&p, pk); /* match type */ | |
537 | while (isxdigit(*p)) | |
b4161d10 JH |
538 | { |
539 | value = toupper(*p) - (isdigit(*p) ? '0' : '7') << 4; | |
540 | if (isxdigit(*++p)) | |
541 | { | |
542 | value |= toupper(*p) - (isdigit(*p) ? '0' : '7'); | |
543 | p++; | |
544 | } | |
545 | *pk++ = value & 255; | |
546 | } | |
547 | ||
d2a2c69b | 548 | break; |
b4161d10 | 549 | |
c55a77db | 550 | case ns_t_srv: |
d2a2c69b JH |
551 | for (i = 0; i < 3; i++) |
552 | { | |
553 | value = 0; | |
554 | while (isdigit(*p)) value = value*10 + *p++ - '0'; | |
555 | while (isspace(*p)) p++; | |
556 | *pk++ = (value >> 8) & 255; | |
557 | *pk++ = value & 255; | |
558 | } | |
c55a77db PH |
559 | |
560 | /* Fall through */ | |
561 | ||
562 | case ns_t_cname: | |
563 | case ns_t_ns: | |
564 | case ns_t_ptr: | |
d2a2c69b JH |
565 | if (ep[-1] != '.') sprintf(CS ep, "%s.", zone); |
566 | pk = packname(p, pk); | |
567 | break; | |
c55a77db PH |
568 | } |
569 | ||
570 | /* Fill in the length, and we are done with this RR */ | |
571 | ||
572 | rdlptr[0] = ((pk - rdlptr - 2) >> 8) & 255; | |
573 | rdlptr[1] = (pk -rdlptr - 2) & 255; | |
c55a77db PH |
574 | } |
575 | ||
576 | *pkptr = pk; | |
577 | return (yield == HOST_NOT_FOUND && pass_on_not_found)? PASS_ON : yield; | |
578 | } | |
579 | ||
580 | ||
846430d9 JH |
581 | static void |
582 | alarmfn(int sig) | |
583 | { | |
584 | } | |
c55a77db | 585 | |
dd2a32ad JH |
586 | |
587 | /************************************************* | |
588 | * Special-purpose domains * | |
589 | *************************************************/ | |
590 | ||
591 | static int | |
592 | special_manyhome(uschar * packet, uschar * domain) | |
593 | { | |
594 | uschar *pk = packet + 12; | |
595 | uschar *rdlptr; | |
596 | int i, j; | |
597 | ||
598 | memset(packet, 0, 12); | |
599 | ||
600 | for (i = 104; i <= 111; i++) for (j = 0; j <= 255; j++) | |
601 | { | |
602 | pk = packname(domain, pk); | |
603 | *pk++ = (ns_t_a >> 8) & 255; | |
604 | *pk++ = (ns_t_a) & 255; | |
605 | *pk++ = 0; | |
606 | *pk++ = 1; /* class = IN */ | |
607 | pk += 4; /* TTL field; don't care */ | |
608 | rdlptr = pk; /* remember rdlength field */ | |
609 | pk += 2; | |
610 | ||
611 | *pk++ = 10; *pk++ = 250; *pk++ = i; *pk++ = j; | |
612 | ||
613 | rdlptr[0] = ((pk - rdlptr - 2) >> 8) & 255; | |
614 | rdlptr[1] = (pk - rdlptr - 2) & 255; | |
615 | } | |
616 | ||
617 | packet[6] = (2048 >> 8) & 255; | |
618 | packet[7] = 2048 & 255; | |
619 | packet[10] = 0; | |
620 | packet[11] = 0; | |
621 | ||
622 | (void)fwrite(packet, 1, pk - packet, stdout); | |
623 | return 0; | |
624 | } | |
625 | ||
626 | static int | |
627 | special_again(uschar * packet, uschar * domain) | |
628 | { | |
629 | int delay = atoi(CCS domain); /* digits at the start of the name */ | |
630 | if (delay > 0) sleep(delay); | |
631 | return TRY_AGAIN; | |
632 | } | |
633 | ||
634 | ||
c55a77db PH |
635 | /************************************************* |
636 | * Entry point and main program * | |
637 | *************************************************/ | |
638 | ||
639 | int | |
640 | main(int argc, char **argv) | |
641 | { | |
642 | FILE *f; | |
643 | DIR *d; | |
75e0e026 | 644 | int domlen, qtypelen; |
c55a77db PH |
645 | int yield, count; |
646 | int i; | |
647 | int zonecount = 0; | |
c55a77db | 648 | struct dirent *de; |
c55a77db PH |
649 | zoneitem zones[32]; |
650 | uschar *qualify = NULL; | |
651 | uschar *p, *zone; | |
652 | uschar *zonefile = NULL; | |
653 | uschar domain[256]; | |
654 | uschar buffer[256]; | |
655 | uschar qtype[12]; | |
1fb7660f | 656 | uschar packet[2048 * 32 + 32]; |
c55a77db | 657 | uschar *pk = packet; |
4d4c2a9b | 658 | BOOL dnssec; |
589b3179 | 659 | BOOL aa; |
c55a77db | 660 | |
846430d9 JH |
661 | signal(SIGALRM, alarmfn); |
662 | ||
c55a77db PH |
663 | if (argc != 4) |
664 | { | |
665 | fprintf(stderr, "fakens: expected 3 arguments, received %d\n", argc-1); | |
666 | return NO_RECOVERY; | |
667 | } | |
668 | ||
669 | /* Find the zones */ | |
670 | ||
5f3d0983 | 671 | (void)sprintf(CS buffer, "%s/dnszones", argv[1]); |
c55a77db PH |
672 | |
673 | d = opendir(CCS buffer); | |
674 | if (d == NULL) | |
675 | { | |
676 | fprintf(stderr, "fakens: failed to opendir %s: %s\n", buffer, | |
677 | strerror(errno)); | |
678 | return NO_RECOVERY; | |
679 | } | |
680 | ||
681 | while ((de = readdir(d)) != NULL) | |
682 | { | |
e265af1f | 683 | uschar *name = US de->d_name; |
c55a77db PH |
684 | if (Ustrncmp(name, "qualify.", 8) == 0) |
685 | { | |
e265af1f | 686 | qualify = fcopystring(US "%s", name + 7); |
c55a77db PH |
687 | continue; |
688 | } | |
689 | if (Ustrncmp(name, "db.", 3) != 0) continue; | |
690 | if (Ustrncmp(name + 3, "ip4.", 4) == 0) | |
e265af1f | 691 | zones[zonecount].zone = fcopystring(US "%s.in-addr.arpa", name + 6); |
c55a77db | 692 | else if (Ustrncmp(name + 3, "ip6.", 4) == 0) |
e265af1f | 693 | zones[zonecount].zone = fcopystring(US "%s.ip6.arpa", name + 6); |
c55a77db | 694 | else |
e265af1f JH |
695 | zones[zonecount].zone = fcopystring(US "%s", name + 2); |
696 | zones[zonecount++].zonefile = fcopystring(US "%s", name); | |
c55a77db PH |
697 | } |
698 | (void)closedir(d); | |
699 | ||
700 | /* Get the RR type and upper case it, and check that we recognize it. */ | |
701 | ||
702 | Ustrncpy(qtype, argv[3], sizeof(qtype)); | |
703 | qtypelen = Ustrlen(qtype); | |
704 | for (p = qtype; *p != 0; p++) *p = toupper(*p); | |
705 | ||
1fb7660f JH |
706 | /* Find the domain, lower case it, deal with any specials, |
707 | check that it is in a zone that we handle, | |
c55a77db PH |
708 | and set up the zone file name. The zone names in the table all start with a |
709 | dot. */ | |
710 | ||
711 | domlen = Ustrlen(argv[2]); | |
712 | if (argv[2][domlen-1] == '.') domlen--; | |
713 | Ustrncpy(domain, argv[2], domlen); | |
714 | domain[domlen] = 0; | |
715 | for (i = 0; i < domlen; i++) domain[i] = tolower(domain[i]); | |
716 | ||
1fb7660f | 717 | if (Ustrcmp(domain, "manyhome.test.ex") == 0 && Ustrcmp(qtype, "A") == 0) |
dd2a32ad JH |
718 | return special_manyhome(packet, domain); |
719 | else if (domlen >= 14 && Ustrcmp(domain + domlen - 14, "test.again.dns") == 0) | |
720 | return special_again(packet, domain); | |
721 | else if (domlen >= 13 && Ustrcmp(domain + domlen - 13, "test.fail.dns") == 0) | |
722 | return NO_RECOVERY; | |
1fb7660f JH |
723 | |
724 | ||
c55a77db PH |
725 | if (Ustrchr(domain, '.') == NULL && qualify != NULL && |
726 | Ustrcmp(domain, "dontqualify") != 0) | |
727 | { | |
728 | Ustrcat(domain, qualify); | |
729 | domlen += Ustrlen(qualify); | |
730 | } | |
731 | ||
732 | for (i = 0; i < zonecount; i++) | |
733 | { | |
734 | int zlen; | |
735 | zone = zones[i].zone; | |
736 | zlen = Ustrlen(zone); | |
737 | if (Ustrcmp(domain, zone+1) == 0 || (domlen >= zlen && | |
738 | Ustrcmp(domain + domlen - zlen, zone) == 0)) | |
739 | { | |
740 | zonefile = zones[i].zonefile; | |
741 | break; | |
742 | } | |
743 | } | |
744 | ||
745 | if (zonefile == NULL) | |
746 | { | |
747 | fprintf(stderr, "fakens: query not in faked zone: domain is: %s\n", domain); | |
748 | return PASS_ON; | |
749 | } | |
750 | ||
5f3d0983 | 751 | (void)sprintf(CS buffer, "%s/dnszones/%s", argv[1], zonefile); |
c55a77db PH |
752 | |
753 | /* Initialize the start of the response packet. We don't have to fake up | |
754 | everything, because we know that Exim will look only at the answer and | |
755 | additional section parts. */ | |
756 | ||
757 | memset(packet, 0, 12); | |
758 | pk += 12; | |
759 | ||
760 | /* Open the zone file. */ | |
761 | ||
42ec9880 | 762 | f = fopen(CS buffer, "r"); |
c55a77db PH |
763 | if (f == NULL) |
764 | { | |
765 | fprintf(stderr, "fakens: failed to open %s: %s\n", buffer, strerror(errno)); | |
766 | return NO_RECOVERY; | |
767 | } | |
768 | ||
769 | /* Find the records we want, and add them to the result. */ | |
770 | ||
771 | count = 0; | |
589b3179 | 772 | yield = find_records(f, zone, domain, qtype, qtypelen, &pk, &count, &dnssec, &aa); |
c55a77db PH |
773 | if (yield == NO_RECOVERY) goto END_OFF; |
774 | ||
775 | packet[6] = (count >> 8) & 255; | |
776 | packet[7] = count & 255; | |
777 | ||
75e0e026 PH |
778 | /* There is no need to return any additional records because Exim no longer |
779 | (from release 4.61) makes any use of them. */ | |
c55a77db | 780 | |
75e0e026 PH |
781 | packet[10] = 0; |
782 | packet[11] = 0; | |
c55a77db | 783 | |
4d4c2a9b JH |
784 | if (dnssec) |
785 | ((HEADER *)packet)->ad = 1; | |
786 | ||
589b3179 HSHR |
787 | if (aa) |
788 | ((HEADER *)packet)->aa = 1; | |
789 | ||
c55a77db PH |
790 | /* Close the zone file, write the result, and return. */ |
791 | ||
792 | END_OFF: | |
793 | (void)fclose(f); | |
794 | (void)fwrite(packet, 1, pk - packet, stdout); | |
795 | return yield; | |
796 | } | |
797 | ||
589b3179 | 798 | /* vi: aw ai sw=2 sts=2 ts=8 et |
4d4c2a9b | 799 | */ |
c55a77db | 800 | /* End of fakens.c */ |