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 | |
f6584c83 | 58 | as such then the response will have the "AD" bit set. |
589b3179 | 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 | ||
14b3c5bc JH |
64 | Any DNS record line in a zone file can be prefixed with "TTL=" and |
65 | a number of seconds (followed by one space). | |
66 | ||
589b3179 | 67 | */ |
c55a77db PH |
68 | |
69 | #include <ctype.h> | |
70 | #include <stdarg.h> | |
71 | #include <stdio.h> | |
e265af1f | 72 | #include <stdlib.h> |
c55a77db PH |
73 | #include <string.h> |
74 | #include <netdb.h> | |
75 | #include <errno.h> | |
9d787f10 | 76 | #include <signal.h> |
c55a77db | 77 | #include <arpa/nameser.h> |
fd8184e3 | 78 | #include <arpa/inet.h> |
c55a77db | 79 | #include <sys/types.h> |
846430d9 | 80 | #include <sys/time.h> |
c55a77db | 81 | #include <dirent.h> |
2c98a555 | 82 | #include <unistd.h> |
c55a77db PH |
83 | |
84 | #define FALSE 0 | |
85 | #define TRUE 1 | |
86 | #define PASS_ON 5 | |
87 | ||
88 | typedef int BOOL; | |
89 | typedef unsigned char uschar; | |
90 | ||
91 | #define CS (char *) | |
92 | #define CCS (const char *) | |
93 | #define US (unsigned char *) | |
94 | ||
95 | #define Ustrcat(s,t) strcat(CS(s),CCS(t)) | |
96 | #define Ustrchr(s,n) US strchr(CCS(s),n) | |
97 | #define Ustrcmp(s,t) strcmp(CCS(s),CCS(t)) | |
98 | #define Ustrcpy(s,t) strcpy(CS(s),CCS(t)) | |
99 | #define Ustrlen(s) (int)strlen(CCS(s)) | |
100 | #define Ustrncmp(s,t,n) strncmp(CCS(s),CCS(t),n) | |
101 | #define Ustrncpy(s,t,n) strncpy(CS(s),CCS(t),n) | |
d753e599 | 102 | #define Ustrtok(s,t) strtok(CS(s),CCS(t)) |
c55a77db | 103 | |
c55a77db PH |
104 | typedef struct zoneitem { |
105 | uschar *zone; | |
106 | uschar *zonefile; | |
107 | } zoneitem; | |
108 | ||
109 | typedef struct tlist { | |
110 | uschar *name; | |
111 | int value; | |
112 | } tlist; | |
113 | ||
14b3c5bc JH |
114 | #define DEFAULT_TTL 3600U |
115 | ||
c55a77db PH |
116 | /* On some (older?) operating systems, the standard ns_t_xxx definitions are |
117 | not available, and only the older T_xxx ones exist in nameser.h. If ns_t_a is | |
118 | not defined, assume we are in this state. A really old system might not even | |
119 | know about AAAA and SRV at all. */ | |
120 | ||
121 | #ifndef ns_t_a | |
b4161d10 JH |
122 | # define ns_t_a T_A |
123 | # define ns_t_ns T_NS | |
124 | # define ns_t_cname T_CNAME | |
125 | # define ns_t_soa T_SOA | |
126 | # define ns_t_ptr T_PTR | |
127 | # define ns_t_mx T_MX | |
128 | # define ns_t_txt T_TXT | |
129 | # define ns_t_aaaa T_AAAA | |
130 | # define ns_t_srv T_SRV | |
131 | # define ns_t_tlsa T_TLSA | |
132 | # ifndef T_AAAA | |
133 | # define T_AAAA 28 | |
134 | # endif | |
135 | # ifndef T_SRV | |
136 | # define T_SRV 33 | |
137 | # endif | |
138 | # ifndef T_TLSA | |
139 | # define T_TLSA 52 | |
140 | # endif | |
c55a77db PH |
141 | #endif |
142 | ||
143 | static tlist type_list[] = { | |
144 | { US"A", ns_t_a }, | |
145 | { US"NS", ns_t_ns }, | |
146 | { US"CNAME", ns_t_cname }, | |
d2a2c69b | 147 | { US"SOA", ns_t_soa }, |
c55a77db PH |
148 | { US"PTR", ns_t_ptr }, |
149 | { US"MX", ns_t_mx }, | |
150 | { US"TXT", ns_t_txt }, | |
151 | { US"AAAA", ns_t_aaaa }, | |
152 | { US"SRV", ns_t_srv }, | |
b4161d10 | 153 | { US"TLSA", ns_t_tlsa }, |
c55a77db PH |
154 | { NULL, 0 } |
155 | }; | |
156 | ||
157 | ||
158 | ||
159 | /************************************************* | |
160 | * Get memory and sprintf into it * | |
161 | *************************************************/ | |
162 | ||
163 | /* This is used when building a table of zones and their files. | |
164 | ||
165 | Arguments: | |
166 | format a format string | |
167 | ... arguments | |
168 | ||
169 | Returns: pointer to formatted string | |
170 | */ | |
171 | ||
172 | static uschar * | |
173 | fcopystring(uschar *format, ...) | |
174 | { | |
175 | uschar *yield; | |
176 | char buffer[256]; | |
177 | va_list ap; | |
178 | va_start(ap, format); | |
e265af1f | 179 | vsprintf(buffer, CS format, ap); |
c55a77db PH |
180 | va_end(ap); |
181 | yield = (uschar *)malloc(Ustrlen(buffer) + 1); | |
182 | Ustrcpy(yield, buffer); | |
183 | return yield; | |
184 | } | |
185 | ||
186 | ||
187 | /************************************************* | |
188 | * Pack name into memory * | |
189 | *************************************************/ | |
190 | ||
191 | /* This function packs a domain name into memory according to DNS rules. At | |
192 | present, it doesn't do any compression. | |
193 | ||
194 | Arguments: | |
195 | name the name | |
196 | pk where to put it | |
197 | ||
198 | Returns: the updated value of pk | |
199 | */ | |
200 | ||
201 | static uschar * | |
202 | packname(uschar *name, uschar *pk) | |
203 | { | |
204 | while (*name != 0) | |
205 | { | |
206 | uschar *p = name; | |
207 | while (*p != 0 && *p != '.') p++; | |
208 | *pk++ = (p - name); | |
209 | memmove(pk, name, p - name); | |
210 | pk += p - name; | |
211 | name = (*p == 0)? p : p + 1; | |
212 | } | |
213 | *pk++ = 0; | |
214 | return pk; | |
215 | } | |
216 | ||
36b894a6 JH |
217 | uschar * |
218 | bytefield(uschar ** pp, uschar * pk) | |
219 | { | |
220 | unsigned value = 0; | |
221 | uschar * p = *pp; | |
222 | ||
223 | while (isdigit(*p)) value = value*10 + *p++ - '0'; | |
224 | while (isspace(*p)) p++; | |
225 | *pp = p; | |
226 | *pk++ = value & 255; | |
227 | return pk; | |
228 | } | |
229 | ||
b4161d10 JH |
230 | uschar * |
231 | shortfield(uschar ** pp, uschar * pk) | |
232 | { | |
233 | unsigned value = 0; | |
234 | uschar * p = *pp; | |
235 | ||
236 | while (isdigit(*p)) value = value*10 + *p++ - '0'; | |
237 | while (isspace(*p)) p++; | |
238 | *pp = p; | |
239 | *pk++ = (value >> 8) & 255; | |
240 | *pk++ = value & 255; | |
241 | return pk; | |
242 | } | |
243 | ||
d2a2c69b JH |
244 | uschar * |
245 | longfield(uschar ** pp, uschar * pk) | |
246 | { | |
247 | unsigned long value = 0; | |
248 | uschar * p = *pp; | |
249 | ||
250 | while (isdigit(*p)) value = value*10 + *p++ - '0'; | |
251 | while (isspace(*p)) p++; | |
252 | *pp = p; | |
253 | *pk++ = (value >> 24) & 255; | |
254 | *pk++ = (value >> 16) & 255; | |
255 | *pk++ = (value >> 8) & 255; | |
256 | *pk++ = value & 255; | |
257 | return pk; | |
258 | } | |
259 | ||
c55a77db PH |
260 | |
261 | ||
846430d9 JH |
262 | /*************************************************/ |
263 | ||
264 | static void | |
265 | milliwait(struct itimerval *itval) | |
266 | { | |
267 | sigset_t sigmask; | |
268 | sigset_t old_sigmask; | |
269 | ||
270 | if (itval->it_value.tv_usec < 100 && itval->it_value.tv_sec == 0) | |
271 | return; | |
272 | (void)sigemptyset(&sigmask); /* Empty mask */ | |
273 | (void)sigaddset(&sigmask, SIGALRM); /* Add SIGALRM */ | |
274 | (void)sigprocmask(SIG_BLOCK, &sigmask, &old_sigmask); /* Block SIGALRM */ | |
275 | (void)setitimer(ITIMER_REAL, itval, NULL); /* Start timer */ | |
276 | (void)sigfillset(&sigmask); /* All signals */ | |
277 | (void)sigdelset(&sigmask, SIGALRM); /* Remove SIGALRM */ | |
278 | (void)sigsuspend(&sigmask); /* Until SIGALRM */ | |
279 | (void)sigprocmask(SIG_SETMASK, &old_sigmask, NULL); /* Restore mask */ | |
280 | } | |
281 | ||
282 | static void | |
283 | millisleep(int msec) | |
284 | { | |
285 | struct itimerval itval; | |
286 | itval.it_interval.tv_sec = 0; | |
287 | itval.it_interval.tv_usec = 0; | |
288 | itval.it_value.tv_sec = msec/1000; | |
289 | itval.it_value.tv_usec = (msec % 1000) * 1000; | |
290 | milliwait(&itval); | |
291 | } | |
292 | ||
293 | ||
c55a77db PH |
294 | /************************************************* |
295 | * Scan file for RRs * | |
296 | *************************************************/ | |
297 | ||
298 | /* This function scans an open "zone file" for appropriate records, and adds | |
299 | any that are found to the output buffer. | |
300 | ||
301 | Arguments: | |
302 | f the input FILE | |
303 | zone the current zone name | |
304 | domain the domain we are looking for | |
305 | qtype the type of RR we want | |
306 | qtypelen the length of qtype | |
307 | pkptr points to the output buffer pointer; this is updated | |
308 | countptr points to the record count; this is updated | |
f6584c83 HSHR |
309 | dnssec points to the AD flag indicator; this is updated |
310 | aa points to the AA flag indicator; this is updated | |
c55a77db PH |
311 | |
312 | Returns: 0 on success, else HOST_NOT_FOUND or NO_DATA or NO_RECOVERY or | |
313 | PASS_ON - the latter if a "PASS ON NOT FOUND" line is seen | |
314 | */ | |
315 | ||
316 | static int | |
317 | find_records(FILE *f, uschar *zone, uschar *domain, uschar *qtype, | |
589b3179 | 318 | int qtypelen, uschar **pkptr, int *countptr, BOOL * dnssec, BOOL * aa) |
c55a77db PH |
319 | { |
320 | int yield = HOST_NOT_FOUND; | |
c55a77db PH |
321 | int domainlen = Ustrlen(domain); |
322 | BOOL pass_on_not_found = FALSE; | |
323 | tlist *typeptr; | |
324 | uschar *pk = *pkptr; | |
325 | uschar buffer[256]; | |
326 | uschar rrdomain[256]; | |
75e0e026 | 327 | uschar RRdomain[256]; |
c55a77db | 328 | |
c55a77db | 329 | |
f6584c83 | 330 | /* Decode the required type */ |
c55a77db PH |
331 | for (typeptr = type_list; typeptr->name != NULL; typeptr++) |
332 | { if (Ustrcmp(typeptr->name, qtype) == 0) break; } | |
333 | if (typeptr->name == NULL) | |
334 | { | |
335 | fprintf(stderr, "fakens: unknown record type %s\n", qtype); | |
336 | return NO_RECOVERY; | |
337 | } | |
338 | ||
339 | rrdomain[0] = 0; /* No previous domain */ | |
340 | (void)fseek(f, 0, SEEK_SET); /* Start again at the beginning */ | |
341 | ||
f6584c83 HSHR |
342 | if (dnssec) *dnssec = TRUE; /* cancelled by first nonsecure rec found */ |
343 | if (aa) *aa = TRUE; /* cancelled by first non-aa rec found */ | |
4d4c2a9b | 344 | |
c55a77db PH |
345 | /* Scan for RRs */ |
346 | ||
347 | while (fgets(CS buffer, sizeof(buffer), f) != NULL) | |
348 | { | |
349 | uschar *rdlptr; | |
350 | uschar *p, *ep, *pp; | |
351 | BOOL found_cname = FALSE; | |
d2a2c69b | 352 | int i, value; |
c55a77db PH |
353 | int tvalue = typeptr->value; |
354 | int qtlen = qtypelen; | |
4d4c2a9b | 355 | BOOL rr_sec = FALSE; |
589b3179 | 356 | BOOL rr_aa = FALSE; |
846430d9 | 357 | int delay = 0; |
14b3c5bc | 358 | uint ttl = DEFAULT_TTL; |
c55a77db PH |
359 | |
360 | p = buffer; | |
361 | while (isspace(*p)) p++; | |
362 | if (*p == 0 || *p == ';') continue; | |
363 | ||
4d4c2a9b | 364 | if (Ustrncmp(p, US"PASS ON NOT FOUND", 17) == 0) |
c55a77db PH |
365 | { |
366 | pass_on_not_found = TRUE; | |
367 | continue; | |
368 | } | |
369 | ||
370 | ep = buffer + Ustrlen(buffer); | |
371 | while (isspace(ep[-1])) ep--; | |
372 | *ep = 0; | |
373 | ||
374 | p = buffer; | |
846430d9 | 375 | for (;;) |
1fb7660f | 376 | { |
f6584c83 | 377 | if (Ustrncmp(p, US"DNSSEC ", 7) == 0) /* tagged as secure */ |
1fb7660f JH |
378 | { |
379 | rr_sec = TRUE; | |
380 | p += 7; | |
381 | } | |
f6584c83 | 382 | else if (Ustrncmp(p, US"AA ", 3) == 0) /* tagged as authoritive */ |
589b3179 HSHR |
383 | { |
384 | rr_aa = TRUE; | |
385 | p += 3; | |
386 | } | |
f6584c83 | 387 | else if (Ustrncmp(p, US"DELAY=", 6) == 0) /* delay before response */ |
1fb7660f JH |
388 | { |
389 | for (p += 6; *p >= '0' && *p <= '9'; p++) delay = delay*10 + *p - '0'; | |
6aa849d3 | 390 | if (isspace(*p)) p++; |
1fb7660f | 391 | } |
14b3c5bc JH |
392 | else if (Ustrncmp(p, US"TTL=", 4) == 0) /* TTL for record */ |
393 | { | |
394 | ttl = 0; | |
395 | for (p += 4; *p >= '0' && *p <= '9'; p++) ttl = ttl*10 + *p - '0'; | |
396 | if (isspace(*p)) p++; | |
397 | } | |
1fb7660f JH |
398 | else |
399 | break; | |
400 | } | |
4d4c2a9b | 401 | |
6aa849d3 | 402 | if (!isspace(*p)) /* new domain name */ |
c55a77db PH |
403 | { |
404 | uschar *pp = rrdomain; | |
75e0e026 PH |
405 | uschar *PP = RRdomain; |
406 | while (!isspace(*p)) | |
407 | { | |
408 | *pp++ = tolower(*p); | |
409 | *PP++ = *p++; | |
410 | } | |
411 | if (pp[-1] != '.') | |
412 | { | |
413 | Ustrcpy(pp, zone); | |
414 | Ustrcpy(PP, zone); | |
415 | } | |
416 | else | |
417 | { | |
418 | pp[-1] = 0; | |
419 | PP[-1] = 0; | |
420 | } | |
6aa849d3 | 421 | } /* else use previous line's domain name */ |
c55a77db PH |
422 | |
423 | /* Compare domain names; first check for a wildcard */ | |
424 | ||
425 | if (rrdomain[0] == '*') | |
426 | { | |
427 | int restlen = Ustrlen(rrdomain) - 1; | |
428 | if (domainlen > restlen && | |
429 | Ustrcmp(domain + domainlen - restlen, rrdomain + 1) != 0) continue; | |
430 | } | |
431 | ||
432 | /* Not a wildcard RR */ | |
433 | ||
434 | else if (Ustrcmp(domain, rrdomain) != 0) continue; | |
435 | ||
436 | /* The domain matches */ | |
437 | ||
438 | if (yield == HOST_NOT_FOUND) yield = NO_DATA; | |
439 | ||
440 | /* Compare RR types; a CNAME record is always returned */ | |
441 | ||
442 | while (isspace(*p)) p++; | |
443 | ||
444 | if (Ustrncmp(p, "CNAME", 5) == 0) | |
445 | { | |
446 | tvalue = ns_t_cname; | |
447 | qtlen = 5; | |
448 | found_cname = TRUE; | |
449 | } | |
450 | else if (Ustrncmp(p, qtype, qtypelen) != 0 || !isspace(p[qtypelen])) continue; | |
451 | ||
452 | /* Found a relevant record */ | |
846430d9 JH |
453 | if (delay) |
454 | millisleep(delay); | |
455 | ||
f6584c83 HSHR |
456 | if (dnssec && !rr_sec) |
457 | *dnssec = FALSE; /* cancel AD return */ | |
4d4c2a9b | 458 | |
f6584c83 HSHR |
459 | if (aa && !rr_aa) |
460 | *aa = FALSE; /* cancel AA return */ | |
589b3179 | 461 | |
c55a77db PH |
462 | yield = 0; |
463 | *countptr = *countptr + 1; | |
464 | ||
465 | p += qtlen; | |
466 | while (isspace(*p)) p++; | |
467 | ||
75e0e026 PH |
468 | /* For a wildcard record, use the search name; otherwise use the record's |
469 | name in its original case because it might contain upper case letters. */ | |
470 | ||
471 | pk = packname((rrdomain[0] == '*')? domain : RRdomain, pk); | |
c55a77db PH |
472 | *pk++ = (tvalue >> 8) & 255; |
473 | *pk++ = (tvalue) & 255; | |
474 | *pk++ = 0; | |
475 | *pk++ = 1; /* class = IN */ | |
476 | ||
14b3c5bc JH |
477 | *pk++ = (ttl >>24) & 255; |
478 | *pk++ = (ttl >>16) & 255; | |
479 | *pk++ = (ttl >> 8) & 255; | |
480 | *pk++ = ttl & 255; | |
c55a77db PH |
481 | |
482 | rdlptr = pk; /* remember rdlength field */ | |
483 | pk += 2; | |
484 | ||
485 | /* The rest of the data depends on the type */ | |
486 | ||
487 | switch (tvalue) | |
488 | { | |
d2a2c69b | 489 | case ns_t_soa: |
d753e599 | 490 | p = Ustrtok(p, " "); |
d2a2c69b JH |
491 | ep = p + strlen(p); |
492 | if (ep[-1] != '.') sprintf(CS ep, "%s.", zone); | |
f6584c83 | 493 | pk = packname(p, pk); /* primary ns */ |
d753e599 | 494 | p = Ustrtok(NULL, " "); |
f6584c83 | 495 | pk = packname(p , pk); /* responsible mailbox */ |
d2a2c69b JH |
496 | *(p += strlen(p)) = ' '; |
497 | while (isspace(*p)) p++; | |
f6584c83 HSHR |
498 | pk = longfield(&p, pk); /* serial */ |
499 | pk = longfield(&p, pk); /* refresh */ | |
500 | pk = longfield(&p, pk); /* retry */ | |
501 | pk = longfield(&p, pk); /* expire */ | |
502 | pk = longfield(&p, pk); /* minimum */ | |
d2a2c69b | 503 | break; |
c55a77db PH |
504 | |
505 | case ns_t_a: | |
fd8184e3 HSHR |
506 | inet_pton(AF_INET, p, pk); /* FIXME: error checking */ |
507 | pk += 4; | |
d2a2c69b | 508 | break; |
c55a77db | 509 | |
c55a77db | 510 | case ns_t_aaaa: |
fd8184e3 HSHR |
511 | inet_pton(AF_INET6, p, pk); /* FIXME: error checking */ |
512 | pk += 16; | |
d2a2c69b | 513 | break; |
c55a77db PH |
514 | |
515 | case ns_t_mx: | |
d2a2c69b JH |
516 | pk = shortfield(&p, pk); |
517 | if (ep[-1] != '.') sprintf(CS ep, "%s.", zone); | |
518 | pk = packname(p, pk); | |
519 | break; | |
c55a77db PH |
520 | |
521 | case ns_t_txt: | |
d2a2c69b JH |
522 | pp = pk++; |
523 | if (*p == '"') p++; /* Should always be the case */ | |
524 | while (*p != 0 && *p != '"') *pk++ = *p++; | |
525 | *pp = pk - pp - 1; | |
526 | break; | |
c55a77db | 527 | |
b4161d10 | 528 | case ns_t_tlsa: |
f6584c83 HSHR |
529 | pk = bytefield(&p, pk); /* usage */ |
530 | pk = bytefield(&p, pk); /* selector */ | |
531 | pk = bytefield(&p, pk); /* match type */ | |
d2a2c69b | 532 | while (isxdigit(*p)) |
b4161d10 JH |
533 | { |
534 | value = toupper(*p) - (isdigit(*p) ? '0' : '7') << 4; | |
535 | if (isxdigit(*++p)) | |
f6584c83 HSHR |
536 | { |
537 | value |= toupper(*p) - (isdigit(*p) ? '0' : '7'); | |
538 | p++; | |
539 | } | |
b4161d10 JH |
540 | *pk++ = value & 255; |
541 | } | |
542 | ||
d2a2c69b | 543 | break; |
b4161d10 | 544 | |
c55a77db | 545 | case ns_t_srv: |
d2a2c69b | 546 | for (i = 0; i < 3; i++) |
f6584c83 HSHR |
547 | { |
548 | value = 0; | |
549 | while (isdigit(*p)) value = value*10 + *p++ - '0'; | |
550 | while (isspace(*p)) p++; | |
551 | *pk++ = (value >> 8) & 255; | |
552 | *pk++ = value & 255; | |
553 | } | |
c55a77db PH |
554 | |
555 | /* Fall through */ | |
556 | ||
557 | case ns_t_cname: | |
558 | case ns_t_ns: | |
559 | case ns_t_ptr: | |
d2a2c69b JH |
560 | if (ep[-1] != '.') sprintf(CS ep, "%s.", zone); |
561 | pk = packname(p, pk); | |
562 | break; | |
c55a77db PH |
563 | } |
564 | ||
565 | /* Fill in the length, and we are done with this RR */ | |
566 | ||
567 | rdlptr[0] = ((pk - rdlptr - 2) >> 8) & 255; | |
568 | rdlptr[1] = (pk -rdlptr - 2) & 255; | |
c55a77db PH |
569 | } |
570 | ||
571 | *pkptr = pk; | |
572 | return (yield == HOST_NOT_FOUND && pass_on_not_found)? PASS_ON : yield; | |
573 | } | |
574 | ||
575 | ||
846430d9 JH |
576 | static void |
577 | alarmfn(int sig) | |
578 | { | |
579 | } | |
c55a77db | 580 | |
dd2a32ad JH |
581 | |
582 | /************************************************* | |
583 | * Special-purpose domains * | |
584 | *************************************************/ | |
585 | ||
586 | static int | |
587 | special_manyhome(uschar * packet, uschar * domain) | |
588 | { | |
589 | uschar *pk = packet + 12; | |
590 | uschar *rdlptr; | |
591 | int i, j; | |
592 | ||
593 | memset(packet, 0, 12); | |
594 | ||
595 | for (i = 104; i <= 111; i++) for (j = 0; j <= 255; j++) | |
596 | { | |
597 | pk = packname(domain, pk); | |
598 | *pk++ = (ns_t_a >> 8) & 255; | |
599 | *pk++ = (ns_t_a) & 255; | |
600 | *pk++ = 0; | |
601 | *pk++ = 1; /* class = IN */ | |
602 | pk += 4; /* TTL field; don't care */ | |
603 | rdlptr = pk; /* remember rdlength field */ | |
604 | pk += 2; | |
605 | ||
606 | *pk++ = 10; *pk++ = 250; *pk++ = i; *pk++ = j; | |
607 | ||
608 | rdlptr[0] = ((pk - rdlptr - 2) >> 8) & 255; | |
609 | rdlptr[1] = (pk - rdlptr - 2) & 255; | |
610 | } | |
611 | ||
612 | packet[6] = (2048 >> 8) & 255; | |
613 | packet[7] = 2048 & 255; | |
614 | packet[10] = 0; | |
615 | packet[11] = 0; | |
616 | ||
617 | (void)fwrite(packet, 1, pk - packet, stdout); | |
618 | return 0; | |
619 | } | |
620 | ||
621 | static int | |
622 | special_again(uschar * packet, uschar * domain) | |
623 | { | |
624 | int delay = atoi(CCS domain); /* digits at the start of the name */ | |
625 | if (delay > 0) sleep(delay); | |
626 | return TRY_AGAIN; | |
627 | } | |
628 | ||
629 | ||
c55a77db PH |
630 | /************************************************* |
631 | * Entry point and main program * | |
632 | *************************************************/ | |
633 | ||
634 | int | |
635 | main(int argc, char **argv) | |
636 | { | |
637 | FILE *f; | |
638 | DIR *d; | |
75e0e026 | 639 | int domlen, qtypelen; |
c55a77db PH |
640 | int yield, count; |
641 | int i; | |
642 | int zonecount = 0; | |
c55a77db | 643 | struct dirent *de; |
c55a77db PH |
644 | zoneitem zones[32]; |
645 | uschar *qualify = NULL; | |
646 | uschar *p, *zone; | |
647 | uschar *zonefile = NULL; | |
648 | uschar domain[256]; | |
649 | uschar buffer[256]; | |
650 | uschar qtype[12]; | |
1fb7660f | 651 | uschar packet[2048 * 32 + 32]; |
f6584c83 | 652 | HEADER *header = (HEADER *)packet; |
c55a77db | 653 | uschar *pk = packet; |
4d4c2a9b | 654 | BOOL dnssec; |
589b3179 | 655 | BOOL aa; |
c55a77db | 656 | |
846430d9 JH |
657 | signal(SIGALRM, alarmfn); |
658 | ||
c55a77db PH |
659 | if (argc != 4) |
660 | { | |
661 | fprintf(stderr, "fakens: expected 3 arguments, received %d\n", argc-1); | |
662 | return NO_RECOVERY; | |
663 | } | |
664 | ||
665 | /* Find the zones */ | |
666 | ||
5f3d0983 | 667 | (void)sprintf(CS buffer, "%s/dnszones", argv[1]); |
c55a77db PH |
668 | |
669 | d = opendir(CCS buffer); | |
670 | if (d == NULL) | |
671 | { | |
672 | fprintf(stderr, "fakens: failed to opendir %s: %s\n", buffer, | |
673 | strerror(errno)); | |
674 | return NO_RECOVERY; | |
675 | } | |
676 | ||
677 | while ((de = readdir(d)) != NULL) | |
678 | { | |
e265af1f | 679 | uschar *name = US de->d_name; |
c55a77db PH |
680 | if (Ustrncmp(name, "qualify.", 8) == 0) |
681 | { | |
e265af1f | 682 | qualify = fcopystring(US "%s", name + 7); |
c55a77db PH |
683 | continue; |
684 | } | |
685 | if (Ustrncmp(name, "db.", 3) != 0) continue; | |
686 | if (Ustrncmp(name + 3, "ip4.", 4) == 0) | |
e265af1f | 687 | zones[zonecount].zone = fcopystring(US "%s.in-addr.arpa", name + 6); |
c55a77db | 688 | else if (Ustrncmp(name + 3, "ip6.", 4) == 0) |
e265af1f | 689 | zones[zonecount].zone = fcopystring(US "%s.ip6.arpa", name + 6); |
c55a77db | 690 | else |
e265af1f JH |
691 | zones[zonecount].zone = fcopystring(US "%s", name + 2); |
692 | zones[zonecount++].zonefile = fcopystring(US "%s", name); | |
c55a77db PH |
693 | } |
694 | (void)closedir(d); | |
695 | ||
696 | /* Get the RR type and upper case it, and check that we recognize it. */ | |
697 | ||
698 | Ustrncpy(qtype, argv[3], sizeof(qtype)); | |
699 | qtypelen = Ustrlen(qtype); | |
700 | for (p = qtype; *p != 0; p++) *p = toupper(*p); | |
701 | ||
1fb7660f JH |
702 | /* Find the domain, lower case it, deal with any specials, |
703 | check that it is in a zone that we handle, | |
c55a77db PH |
704 | and set up the zone file name. The zone names in the table all start with a |
705 | dot. */ | |
706 | ||
707 | domlen = Ustrlen(argv[2]); | |
708 | if (argv[2][domlen-1] == '.') domlen--; | |
709 | Ustrncpy(domain, argv[2], domlen); | |
710 | domain[domlen] = 0; | |
711 | for (i = 0; i < domlen; i++) domain[i] = tolower(domain[i]); | |
712 | ||
1fb7660f | 713 | if (Ustrcmp(domain, "manyhome.test.ex") == 0 && Ustrcmp(qtype, "A") == 0) |
dd2a32ad JH |
714 | return special_manyhome(packet, domain); |
715 | else if (domlen >= 14 && Ustrcmp(domain + domlen - 14, "test.again.dns") == 0) | |
716 | return special_again(packet, domain); | |
717 | else if (domlen >= 13 && Ustrcmp(domain + domlen - 13, "test.fail.dns") == 0) | |
718 | return NO_RECOVERY; | |
1fb7660f JH |
719 | |
720 | ||
c55a77db PH |
721 | if (Ustrchr(domain, '.') == NULL && qualify != NULL && |
722 | Ustrcmp(domain, "dontqualify") != 0) | |
723 | { | |
724 | Ustrcat(domain, qualify); | |
725 | domlen += Ustrlen(qualify); | |
726 | } | |
727 | ||
728 | for (i = 0; i < zonecount; i++) | |
729 | { | |
730 | int zlen; | |
731 | zone = zones[i].zone; | |
732 | zlen = Ustrlen(zone); | |
733 | if (Ustrcmp(domain, zone+1) == 0 || (domlen >= zlen && | |
734 | Ustrcmp(domain + domlen - zlen, zone) == 0)) | |
735 | { | |
736 | zonefile = zones[i].zonefile; | |
737 | break; | |
738 | } | |
739 | } | |
740 | ||
741 | if (zonefile == NULL) | |
742 | { | |
743 | fprintf(stderr, "fakens: query not in faked zone: domain is: %s\n", domain); | |
744 | return PASS_ON; | |
745 | } | |
746 | ||
5f3d0983 | 747 | (void)sprintf(CS buffer, "%s/dnszones/%s", argv[1], zonefile); |
c55a77db PH |
748 | |
749 | /* Initialize the start of the response packet. We don't have to fake up | |
750 | everything, because we know that Exim will look only at the answer and | |
751 | additional section parts. */ | |
752 | ||
753 | memset(packet, 0, 12); | |
754 | pk += 12; | |
755 | ||
756 | /* Open the zone file. */ | |
757 | ||
42ec9880 | 758 | f = fopen(CS buffer, "r"); |
c55a77db PH |
759 | if (f == NULL) |
760 | { | |
761 | fprintf(stderr, "fakens: failed to open %s: %s\n", buffer, strerror(errno)); | |
762 | return NO_RECOVERY; | |
763 | } | |
764 | ||
765 | /* Find the records we want, and add them to the result. */ | |
766 | ||
767 | count = 0; | |
589b3179 | 768 | yield = find_records(f, zone, domain, qtype, qtypelen, &pk, &count, &dnssec, &aa); |
c55a77db | 769 | if (yield == NO_RECOVERY) goto END_OFF; |
f6584c83 | 770 | header->ancount = htons(count); |
c55a77db | 771 | |
f6584c83 HSHR |
772 | /* If the AA bit should be set (as indicated by the AA prefix in the zone file), |
773 | we are expected to return some records in the authortive section. Bind9: If | |
774 | there is data in the answer section, the authoritive section contains the NS | |
775 | records, otherwise it contains the SOA record. Currently we mimic this | |
776 | behaviour for the first case (there is some answer record). | |
777 | */ | |
778 | ||
779 | if (aa) | |
780 | find_records(f, zone, zone[0] == '.' ? zone+1 : zone, US"NS", 2, &pk, &count, NULL, NULL); | |
781 | header->nscount = htons(count - ntohs(header->ancount)); | |
c55a77db | 782 | |
75e0e026 PH |
783 | /* There is no need to return any additional records because Exim no longer |
784 | (from release 4.61) makes any use of them. */ | |
f6584c83 | 785 | header->arcount = 0; |
c55a77db | 786 | |
4d4c2a9b | 787 | if (dnssec) |
f6584c83 | 788 | header->ad = 1; |
4d4c2a9b | 789 | |
589b3179 | 790 | if (aa) |
f6584c83 | 791 | header->aa = 1; |
589b3179 | 792 | |
c55a77db PH |
793 | /* Close the zone file, write the result, and return. */ |
794 | ||
795 | END_OFF: | |
796 | (void)fclose(f); | |
797 | (void)fwrite(packet, 1, pk - packet, stdout); | |
798 | return yield; | |
799 | } | |
800 | ||
589b3179 | 801 | /* vi: aw ai sw=2 sts=2 ts=8 et |
4d4c2a9b | 802 | */ |
c55a77db | 803 | /* End of fakens.c */ |