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 | |
4c04137d | 28 | exactly the same format as a traditional nameserver response (see RFC 1035) so |
c55a77db PH |
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 | |
ce889807 | 56 | Any DNS record line can be prefixed with "DNSSEC "; |
6aa849d3 | 57 | if all the records found by a lookup are marked |
f6584c83 | 58 | as such then the response will have the "AD" bit set. |
589b3179 | 59 | |
ce889807 JH |
60 | Any DNS record line can be prefixed with "NXDOMAIN "; |
61 | The record will be ignored (but the prefix set still applied); | |
7d8d08c4 | 62 | This lets us return a DNSSEC NXDOMAIN (=> HOST_NOT_FOUND). |
ce889807 JH |
63 | |
64 | Any DNS record line can be prefixed with "AA " | |
6aa849d3 | 65 | if all the records found by a lookup are marked |
589b3179 HSHR |
66 | as such then the response will have the "AA" bit set. |
67 | ||
14b3c5bc JH |
68 | Any DNS record line in a zone file can be prefixed with "TTL=" and |
69 | a number of seconds (followed by one space). | |
70 | ||
589b3179 | 71 | */ |
c55a77db PH |
72 | |
73 | #include <ctype.h> | |
74 | #include <stdarg.h> | |
75 | #include <stdio.h> | |
e265af1f | 76 | #include <stdlib.h> |
c55a77db PH |
77 | #include <string.h> |
78 | #include <netdb.h> | |
79 | #include <errno.h> | |
9d787f10 | 80 | #include <signal.h> |
c55a77db | 81 | #include <arpa/nameser.h> |
fd8184e3 | 82 | #include <arpa/inet.h> |
c55a77db | 83 | #include <sys/types.h> |
846430d9 | 84 | #include <sys/time.h> |
c55a77db | 85 | #include <dirent.h> |
2c98a555 | 86 | #include <unistd.h> |
bba15024 HSHR |
87 | #ifdef HAVE_SYS_SOCKET_H |
88 | #include <sys/socket.h> | |
89 | #endif | |
c55a77db PH |
90 | |
91 | #define FALSE 0 | |
92 | #define TRUE 1 | |
93 | #define PASS_ON 5 | |
94 | ||
95 | typedef int BOOL; | |
96 | typedef 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) | |
cf89e968 | 109 | #define Ustrtok(s,t) (uschar*)strtok(CS(s),CCS(t)) |
c55a77db | 110 | |
c55a77db PH |
111 | typedef struct zoneitem { |
112 | uschar *zone; | |
113 | uschar *zonefile; | |
114 | } zoneitem; | |
115 | ||
116 | typedef struct tlist { | |
117 | uschar *name; | |
118 | int value; | |
119 | } tlist; | |
120 | ||
14b3c5bc JH |
121 | #define DEFAULT_TTL 3600U |
122 | ||
c55a77db PH |
123 | /* On some (older?) operating systems, the standard ns_t_xxx definitions are |
124 | not available, and only the older T_xxx ones exist in nameser.h. If ns_t_a is | |
125 | not defined, assume we are in this state. A really old system might not even | |
126 | know about AAAA and SRV at all. */ | |
127 | ||
128 | #ifndef ns_t_a | |
b4161d10 JH |
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 | |
c55a77db PH |
148 | #endif |
149 | ||
150 | static tlist type_list[] = { | |
151 | { US"A", ns_t_a }, | |
152 | { US"NS", ns_t_ns }, | |
153 | { US"CNAME", ns_t_cname }, | |
d2a2c69b | 154 | { US"SOA", ns_t_soa }, |
c55a77db PH |
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 }, | |
b4161d10 | 160 | { US"TLSA", ns_t_tlsa }, |
c55a77db PH |
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 | ||
172 | Arguments: | |
173 | format a format string | |
174 | ... arguments | |
175 | ||
176 | Returns: pointer to formatted string | |
177 | */ | |
178 | ||
179 | static uschar * | |
180 | fcopystring(uschar *format, ...) | |
181 | { | |
182 | uschar *yield; | |
183 | char buffer[256]; | |
184 | va_list ap; | |
185 | va_start(ap, format); | |
e265af1f | 186 | vsprintf(buffer, CS format, ap); |
c55a77db PH |
187 | va_end(ap); |
188 | yield = (uschar *)malloc(Ustrlen(buffer) + 1); | |
189 | Ustrcpy(yield, buffer); | |
190 | return 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 | |
199 | present, it doesn't do any compression. | |
200 | ||
201 | Arguments: | |
202 | name the name | |
203 | pk where to put it | |
204 | ||
205 | Returns: the updated value of pk | |
206 | */ | |
207 | ||
208 | static uschar * | |
209 | packname(uschar *name, uschar *pk) | |
210 | { | |
211 | while (*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; | |
221 | return pk; | |
222 | } | |
223 | ||
36b894a6 JH |
224 | uschar * |
225 | bytefield(uschar ** pp, uschar * pk) | |
226 | { | |
227 | unsigned value = 0; | |
228 | uschar * p = *pp; | |
229 | ||
230 | while (isdigit(*p)) value = value*10 + *p++ - '0'; | |
231 | while (isspace(*p)) p++; | |
232 | *pp = p; | |
233 | *pk++ = value & 255; | |
234 | return pk; | |
235 | } | |
236 | ||
b4161d10 JH |
237 | uschar * |
238 | shortfield(uschar ** pp, uschar * pk) | |
239 | { | |
240 | unsigned value = 0; | |
241 | uschar * p = *pp; | |
242 | ||
243 | while (isdigit(*p)) value = value*10 + *p++ - '0'; | |
244 | while (isspace(*p)) p++; | |
245 | *pp = p; | |
246 | *pk++ = (value >> 8) & 255; | |
247 | *pk++ = value & 255; | |
248 | return pk; | |
249 | } | |
250 | ||
d2a2c69b JH |
251 | uschar * |
252 | longfield(uschar ** pp, uschar * pk) | |
253 | { | |
254 | unsigned long value = 0; | |
255 | uschar * p = *pp; | |
256 | ||
257 | while (isdigit(*p)) value = value*10 + *p++ - '0'; | |
258 | while (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; | |
264 | return pk; | |
265 | } | |
266 | ||
c55a77db PH |
267 | |
268 | ||
846430d9 JH |
269 | /*************************************************/ |
270 | ||
271 | static void | |
272 | milliwait(struct itimerval *itval) | |
273 | { | |
274 | sigset_t sigmask; | |
275 | sigset_t old_sigmask; | |
276 | ||
277 | if (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 | ||
289 | static void | |
290 | millisleep(int msec) | |
291 | { | |
292 | struct itimerval itval; | |
293 | itval.it_interval.tv_sec = 0; | |
294 | itval.it_interval.tv_usec = 0; | |
295 | itval.it_value.tv_sec = msec/1000; | |
296 | itval.it_value.tv_usec = (msec % 1000) * 1000; | |
297 | milliwait(&itval); | |
298 | } | |
299 | ||
300 | ||
c55a77db PH |
301 | /************************************************* |
302 | * Scan file for RRs * | |
303 | *************************************************/ | |
304 | ||
305 | /* This function scans an open "zone file" for appropriate records, and adds | |
306 | any that are found to the output buffer. | |
307 | ||
308 | Arguments: | |
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 | |
8ea4d064 JH |
316 | dnssec_p points to the AD flag indicator; this is updated |
317 | aa_p points to the AA flag indicator; this is updated | |
c55a77db PH |
318 | |
319 | Returns: 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 | ||
323 | static int | |
324 | find_records(FILE *f, uschar *zone, uschar *domain, uschar *qtype, | |
8ea4d064 | 325 | int qtypelen, uschar **pkptr, int *countptr, BOOL * dnssec_p, BOOL * aa_p) |
c55a77db PH |
326 | { |
327 | int yield = HOST_NOT_FOUND; | |
c55a77db PH |
328 | int domainlen = Ustrlen(domain); |
329 | BOOL pass_on_not_found = FALSE; | |
330 | tlist *typeptr; | |
331 | uschar *pk = *pkptr; | |
332 | uschar buffer[256]; | |
333 | uschar rrdomain[256]; | |
75e0e026 | 334 | uschar RRdomain[256]; |
c55a77db | 335 | |
c55a77db | 336 | |
f6584c83 | 337 | /* Decode the required type */ |
c55a77db PH |
338 | for (typeptr = type_list; typeptr->name != NULL; typeptr++) |
339 | { if (Ustrcmp(typeptr->name, qtype) == 0) break; } | |
340 | if (typeptr->name == NULL) | |
341 | { | |
342 | fprintf(stderr, "fakens: unknown record type %s\n", qtype); | |
343 | return NO_RECOVERY; | |
344 | } | |
345 | ||
346 | rrdomain[0] = 0; /* No previous domain */ | |
347 | (void)fseek(f, 0, SEEK_SET); /* Start again at the beginning */ | |
348 | ||
349 | /* Scan for RRs */ | |
350 | ||
351 | while (fgets(CS buffer, sizeof(buffer), f) != NULL) | |
352 | { | |
353 | uschar *rdlptr; | |
354 | uschar *p, *ep, *pp; | |
355 | BOOL found_cname = FALSE; | |
d2a2c69b | 356 | int i, value; |
c55a77db PH |
357 | int tvalue = typeptr->value; |
358 | int qtlen = qtypelen; | |
4d4c2a9b | 359 | BOOL rr_sec = FALSE; |
589b3179 | 360 | BOOL rr_aa = FALSE; |
ce889807 | 361 | BOOL rr_ignore = FALSE; |
846430d9 | 362 | int delay = 0; |
14b3c5bc | 363 | uint ttl = DEFAULT_TTL; |
c55a77db PH |
364 | |
365 | p = buffer; | |
366 | while (isspace(*p)) p++; | |
367 | if (*p == 0 || *p == ';') continue; | |
368 | ||
4d4c2a9b | 369 | if (Ustrncmp(p, US"PASS ON NOT FOUND", 17) == 0) |
c55a77db PH |
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; | |
846430d9 | 380 | for (;;) |
1fb7660f | 381 | { |
f6584c83 | 382 | if (Ustrncmp(p, US"DNSSEC ", 7) == 0) /* tagged as secure */ |
1fb7660f JH |
383 | { |
384 | rr_sec = TRUE; | |
385 | p += 7; | |
386 | } | |
ce889807 JH |
387 | if (Ustrncmp(p, US"NXDOMAIN ", 9) == 0) /* ignore record content */ |
388 | { | |
389 | rr_ignore = TRUE; | |
390 | p += 9; | |
391 | } | |
4c04137d | 392 | else if (Ustrncmp(p, US"AA ", 3) == 0) /* tagged as authoritative */ |
589b3179 HSHR |
393 | { |
394 | rr_aa = TRUE; | |
395 | p += 3; | |
396 | } | |
f6584c83 | 397 | else if (Ustrncmp(p, US"DELAY=", 6) == 0) /* delay before response */ |
1fb7660f JH |
398 | { |
399 | for (p += 6; *p >= '0' && *p <= '9'; p++) delay = delay*10 + *p - '0'; | |
6aa849d3 | 400 | if (isspace(*p)) p++; |
1fb7660f | 401 | } |
14b3c5bc JH |
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 | } | |
1fb7660f JH |
408 | else |
409 | break; | |
410 | } | |
4d4c2a9b | 411 | |
6aa849d3 | 412 | if (!isspace(*p)) /* new domain name */ |
c55a77db PH |
413 | { |
414 | uschar *pp = rrdomain; | |
75e0e026 PH |
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 | } | |
6aa849d3 | 431 | } /* else use previous line's domain name */ |
c55a77db PH |
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 | ||
e48f2b5b JH |
448 | if (yield == HOST_NOT_FOUND) |
449 | { | |
450 | yield = NO_DATA; | |
8ea4d064 JH |
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 */ | |
e48f2b5b | 453 | } |
c55a77db PH |
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 */ | |
846430d9 JH |
468 | if (delay) |
469 | millisleep(delay); | |
470 | ||
8ea4d064 JH |
471 | if (dnssec_p && !rr_sec) |
472 | *dnssec_p = FALSE; /* cancel AD return */ | |
4d4c2a9b | 473 | |
8ea4d064 JH |
474 | if (aa_p && !rr_aa) |
475 | *aa_p = FALSE; /* cancel AA return */ | |
589b3179 | 476 | |
ce889807 JH |
477 | if (rr_ignore) continue; |
478 | ||
c55a77db PH |
479 | yield = 0; |
480 | *countptr = *countptr + 1; | |
481 | ||
482 | p += qtlen; | |
483 | while (isspace(*p)) p++; | |
484 | ||
75e0e026 PH |
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); | |
c55a77db PH |
489 | *pk++ = (tvalue >> 8) & 255; |
490 | *pk++ = (tvalue) & 255; | |
491 | *pk++ = 0; | |
492 | *pk++ = 1; /* class = IN */ | |
493 | ||
14b3c5bc JH |
494 | *pk++ = (ttl >>24) & 255; |
495 | *pk++ = (ttl >>16) & 255; | |
496 | *pk++ = (ttl >> 8) & 255; | |
497 | *pk++ = ttl & 255; | |
c55a77db PH |
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 | { | |
d2a2c69b | 506 | case ns_t_soa: |
d753e599 | 507 | p = Ustrtok(p, " "); |
cf89e968 | 508 | ep = p + Ustrlen(p); |
d2a2c69b | 509 | if (ep[-1] != '.') sprintf(CS ep, "%s.", zone); |
f6584c83 | 510 | pk = packname(p, pk); /* primary ns */ |
d753e599 | 511 | p = Ustrtok(NULL, " "); |
f6584c83 | 512 | pk = packname(p , pk); /* responsible mailbox */ |
cf89e968 | 513 | *(p += Ustrlen(p)) = ' '; |
d2a2c69b | 514 | while (isspace(*p)) p++; |
f6584c83 HSHR |
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 */ | |
d2a2c69b | 520 | break; |
c55a77db PH |
521 | |
522 | case ns_t_a: | |
cf89e968 | 523 | inet_pton(AF_INET, CCS p, pk); /* FIXME: error checking */ |
fd8184e3 | 524 | pk += 4; |
d2a2c69b | 525 | break; |
c55a77db | 526 | |
c55a77db | 527 | case ns_t_aaaa: |
cf89e968 | 528 | inet_pton(AF_INET6, CCS p, pk); /* FIXME: error checking */ |
fd8184e3 | 529 | pk += 16; |
d2a2c69b | 530 | break; |
c55a77db PH |
531 | |
532 | case ns_t_mx: | |
d2a2c69b JH |
533 | pk = shortfield(&p, pk); |
534 | if (ep[-1] != '.') sprintf(CS ep, "%s.", zone); | |
535 | pk = packname(p, pk); | |
536 | break; | |
c55a77db PH |
537 | |
538 | case ns_t_txt: | |
d2a2c69b JH |
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; | |
c55a77db | 544 | |
b4161d10 | 545 | case ns_t_tlsa: |
f6584c83 HSHR |
546 | pk = bytefield(&p, pk); /* usage */ |
547 | pk = bytefield(&p, pk); /* selector */ | |
548 | pk = bytefield(&p, pk); /* match type */ | |
d2a2c69b | 549 | while (isxdigit(*p)) |
b4161d10 JH |
550 | { |
551 | value = toupper(*p) - (isdigit(*p) ? '0' : '7') << 4; | |
552 | if (isxdigit(*++p)) | |
f6584c83 HSHR |
553 | { |
554 | value |= toupper(*p) - (isdigit(*p) ? '0' : '7'); | |
555 | p++; | |
556 | } | |
b4161d10 JH |
557 | *pk++ = value & 255; |
558 | } | |
559 | ||
d2a2c69b | 560 | break; |
b4161d10 | 561 | |
c55a77db | 562 | case ns_t_srv: |
d2a2c69b | 563 | for (i = 0; i < 3; i++) |
f6584c83 HSHR |
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 | } | |
c55a77db PH |
571 | |
572 | /* Fall through */ | |
573 | ||
574 | case ns_t_cname: | |
575 | case ns_t_ns: | |
576 | case ns_t_ptr: | |
d2a2c69b JH |
577 | if (ep[-1] != '.') sprintf(CS ep, "%s.", zone); |
578 | pk = packname(p, pk); | |
579 | break; | |
c55a77db PH |
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; | |
c55a77db PH |
586 | } |
587 | ||
588 | *pkptr = pk; | |
589 | return (yield == HOST_NOT_FOUND && pass_on_not_found)? PASS_ON : yield; | |
590 | } | |
591 | ||
592 | ||
846430d9 JH |
593 | static void |
594 | alarmfn(int sig) | |
595 | { | |
596 | } | |
c55a77db | 597 | |
dd2a32ad JH |
598 | |
599 | /************************************************* | |
600 | * Special-purpose domains * | |
601 | *************************************************/ | |
602 | ||
603 | static int | |
604 | special_manyhome(uschar * packet, uschar * domain) | |
605 | { | |
606 | uschar *pk = packet + 12; | |
607 | uschar *rdlptr; | |
608 | int i, j; | |
609 | ||
610 | memset(packet, 0, 12); | |
611 | ||
612 | for (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 | ||
629 | packet[6] = (2048 >> 8) & 255; | |
630 | packet[7] = 2048 & 255; | |
631 | packet[10] = 0; | |
632 | packet[11] = 0; | |
633 | ||
634 | (void)fwrite(packet, 1, pk - packet, stdout); | |
635 | return 0; | |
636 | } | |
637 | ||
638 | static int | |
639 | special_again(uschar * packet, uschar * domain) | |
640 | { | |
641 | int delay = atoi(CCS domain); /* digits at the start of the name */ | |
642 | if (delay > 0) sleep(delay); | |
643 | return TRY_AGAIN; | |
644 | } | |
645 | ||
646 | ||
c55a77db PH |
647 | /************************************************* |
648 | * Entry point and main program * | |
649 | *************************************************/ | |
650 | ||
651 | int | |
652 | main(int argc, char **argv) | |
653 | { | |
654 | FILE *f; | |
655 | DIR *d; | |
75e0e026 | 656 | int domlen, qtypelen; |
c55a77db PH |
657 | int yield, count; |
658 | int i; | |
659 | int zonecount = 0; | |
c55a77db | 660 | struct dirent *de; |
c55a77db PH |
661 | zoneitem zones[32]; |
662 | uschar *qualify = NULL; | |
663 | uschar *p, *zone; | |
664 | uschar *zonefile = NULL; | |
665 | uschar domain[256]; | |
666 | uschar buffer[256]; | |
667 | uschar qtype[12]; | |
1fb7660f | 668 | uschar packet[2048 * 32 + 32]; |
f6584c83 | 669 | HEADER *header = (HEADER *)packet; |
c55a77db | 670 | uschar *pk = packet; |
8ea4d064 JH |
671 | BOOL dnssec = FALSE; |
672 | BOOL aa = FALSE; | |
c55a77db | 673 | |
846430d9 JH |
674 | signal(SIGALRM, alarmfn); |
675 | ||
c55a77db PH |
676 | if (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 | ||
5f3d0983 | 684 | (void)sprintf(CS buffer, "%s/dnszones", argv[1]); |
c55a77db | 685 | |
8ea4d064 | 686 | if (!(d = opendir(CCS buffer))) |
c55a77db PH |
687 | { |
688 | fprintf(stderr, "fakens: failed to opendir %s: %s\n", buffer, | |
689 | strerror(errno)); | |
690 | return NO_RECOVERY; | |
691 | } | |
692 | ||
8ea4d064 | 693 | while ((de = readdir(d))) |
c55a77db | 694 | { |
e265af1f | 695 | uschar *name = US de->d_name; |
c55a77db PH |
696 | if (Ustrncmp(name, "qualify.", 8) == 0) |
697 | { | |
e265af1f | 698 | qualify = fcopystring(US "%s", name + 7); |
c55a77db PH |
699 | continue; |
700 | } | |
701 | if (Ustrncmp(name, "db.", 3) != 0) continue; | |
702 | if (Ustrncmp(name + 3, "ip4.", 4) == 0) | |
e265af1f | 703 | zones[zonecount].zone = fcopystring(US "%s.in-addr.arpa", name + 6); |
c55a77db | 704 | else if (Ustrncmp(name + 3, "ip6.", 4) == 0) |
e265af1f | 705 | zones[zonecount].zone = fcopystring(US "%s.ip6.arpa", name + 6); |
c55a77db | 706 | else |
e265af1f JH |
707 | zones[zonecount].zone = fcopystring(US "%s", name + 2); |
708 | zones[zonecount++].zonefile = fcopystring(US "%s", name); | |
c55a77db PH |
709 | } |
710 | (void)closedir(d); | |
711 | ||
712 | /* Get the RR type and upper case it, and check that we recognize it. */ | |
713 | ||
714 | Ustrncpy(qtype, argv[3], sizeof(qtype)); | |
715 | qtypelen = Ustrlen(qtype); | |
716 | for (p = qtype; *p != 0; p++) *p = toupper(*p); | |
717 | ||
1fb7660f JH |
718 | /* Find the domain, lower case it, deal with any specials, |
719 | check that it is in a zone that we handle, | |
c55a77db PH |
720 | and set up the zone file name. The zone names in the table all start with a |
721 | dot. */ | |
722 | ||
723 | domlen = Ustrlen(argv[2]); | |
724 | if (argv[2][domlen-1] == '.') domlen--; | |
725 | Ustrncpy(domain, argv[2], domlen); | |
726 | domain[domlen] = 0; | |
727 | for (i = 0; i < domlen; i++) domain[i] = tolower(domain[i]); | |
728 | ||
1fb7660f | 729 | if (Ustrcmp(domain, "manyhome.test.ex") == 0 && Ustrcmp(qtype, "A") == 0) |
dd2a32ad JH |
730 | return special_manyhome(packet, domain); |
731 | else if (domlen >= 14 && Ustrcmp(domain + domlen - 14, "test.again.dns") == 0) | |
732 | return special_again(packet, domain); | |
733 | else if (domlen >= 13 && Ustrcmp(domain + domlen - 13, "test.fail.dns") == 0) | |
734 | return NO_RECOVERY; | |
1fb7660f JH |
735 | |
736 | ||
c55a77db PH |
737 | if (Ustrchr(domain, '.') == NULL && qualify != NULL && |
738 | Ustrcmp(domain, "dontqualify") != 0) | |
739 | { | |
740 | Ustrcat(domain, qualify); | |
741 | domlen += Ustrlen(qualify); | |
742 | } | |
743 | ||
744 | for (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 | ||
757 | if (zonefile == NULL) | |
758 | { | |
759 | fprintf(stderr, "fakens: query not in faked zone: domain is: %s\n", domain); | |
760 | return PASS_ON; | |
761 | } | |
762 | ||
5f3d0983 | 763 | (void)sprintf(CS buffer, "%s/dnszones/%s", argv[1], zonefile); |
c55a77db | 764 | |
7d8d08c4 | 765 | /* Initialize the start of the response packet. */ |
c55a77db PH |
766 | |
767 | memset(packet, 0, 12); | |
768 | pk += 12; | |
769 | ||
770 | /* Open the zone file. */ | |
771 | ||
7d8d08c4 | 772 | if (!(f = fopen(CS buffer, "r"))) |
c55a77db PH |
773 | { |
774 | fprintf(stderr, "fakens: failed to open %s: %s\n", buffer, strerror(errno)); | |
775 | return NO_RECOVERY; | |
776 | } | |
777 | ||
7d8d08c4 JH |
778 | header->qr = 1; /* query */ |
779 | header->opcode = QUERY; /* standard query */ | |
8ea4d064 | 780 | header->tc = 0; /* no truncation */ |
7d8d08c4 | 781 | |
c55a77db PH |
782 | /* Find the records we want, and add them to the result. */ |
783 | ||
784 | count = 0; | |
589b3179 | 785 | yield = find_records(f, zone, domain, qtype, qtypelen, &pk, &count, &dnssec, &aa); |
c55a77db | 786 | if (yield == NO_RECOVERY) goto END_OFF; |
f6584c83 | 787 | header->ancount = htons(count); |
c55a77db | 788 | |
f6584c83 | 789 | /* If the AA bit should be set (as indicated by the AA prefix in the zone file), |
4c04137d JS |
790 | we are expected to return some records in the authoritative section. Bind9: If |
791 | there is data in the answer section, the authoritative section contains the NS | |
7d8d08c4 | 792 | records, otherwise it contains the SOA record. Mimic that. |
f6584c83 HSHR |
793 | */ |
794 | ||
7d8d08c4 JH |
795 | if (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); | |
f6584c83 | 800 | header->nscount = htons(count - ntohs(header->ancount)); |
c55a77db | 801 | |
75e0e026 PH |
802 | /* There is no need to return any additional records because Exim no longer |
803 | (from release 4.61) makes any use of them. */ | |
f6584c83 | 804 | header->arcount = 0; |
c55a77db | 805 | |
4d4c2a9b | 806 | if (dnssec) |
f6584c83 | 807 | header->ad = 1; |
4d4c2a9b | 808 | |
589b3179 | 809 | if (aa) |
f6584c83 | 810 | header->aa = 1; |
589b3179 | 811 | |
c55a77db PH |
812 | /* Close the zone file, write the result, and return. */ |
813 | ||
814 | END_OFF: | |
815 | (void)fclose(f); | |
816 | (void)fwrite(packet, 1, pk - packet, stdout); | |
817 | return yield; | |
818 | } | |
819 | ||
589b3179 | 820 | /* vi: aw ai sw=2 sts=2 ts=8 et |
4d4c2a9b | 821 | */ |
c55a77db | 822 | /* End of fakens.c */ |