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74b2466e LP |
1 | /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ |
2 | ||
3 | /*** | |
4 | This file is part of systemd. | |
5 | ||
6 | Copyright 2014 Lennart Poettering | |
7 | ||
8 | systemd is free software; you can redistribute it and/or modify it | |
9 | under the terms of the GNU Lesser General Public License as published by | |
10 | the Free Software Foundation; either version 2.1 of the License, or | |
11 | (at your option) any later version. | |
12 | ||
13 | systemd is distributed in the hope that it will be useful, but | |
14 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
16 | Lesser General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU Lesser General Public License | |
19 | along with systemd; If not, see <http://www.gnu.org/licenses/>. | |
20 | ***/ | |
21 | ||
bdf10b5b LP |
22 | #ifdef HAVE_LIBIDN |
23 | #include <idna.h> | |
24 | #include <stringprep.h> | |
25 | #endif | |
26 | ||
a8fbdf54 TA |
27 | #include <endian.h> |
28 | #include <netinet/in.h> | |
29 | #include <stdio.h> | |
30 | #include <string.h> | |
31 | #include <sys/socket.h> | |
32 | ||
b5efdb8a | 33 | #include "alloc-util.h" |
4ad7f276 | 34 | #include "dns-domain.h" |
a8fbdf54 | 35 | #include "hashmap.h" |
e4e73a63 | 36 | #include "hexdecoct.h" |
a8fbdf54 TA |
37 | #include "in-addr-util.h" |
38 | #include "macro.h" | |
6bedfcbb LP |
39 | #include "parse-util.h" |
40 | #include "string-util.h" | |
dc477e73 | 41 | #include "strv.h" |
0a49b6b6 | 42 | #include "utf8.h" |
74b2466e LP |
43 | |
44 | int dns_label_unescape(const char **name, char *dest, size_t sz) { | |
45 | const char *n; | |
46 | char *d; | |
47 | int r = 0; | |
48 | ||
49 | assert(name); | |
50 | assert(*name); | |
74b2466e LP |
51 | |
52 | n = *name; | |
53 | d = dest; | |
54 | ||
55 | for (;;) { | |
56 | if (*n == '.') { | |
57 | n++; | |
58 | break; | |
59 | } | |
60 | ||
61 | if (*n == 0) | |
62 | break; | |
63 | ||
1fa65c59 LP |
64 | if (r >= DNS_LABEL_MAX) |
65 | return -EINVAL; | |
66 | ||
37ade128 LP |
67 | if (sz <= 0) |
68 | return -ENOBUFS; | |
69 | ||
74b2466e LP |
70 | if (*n == '\\') { |
71 | /* Escaped character */ | |
72 | ||
73 | n++; | |
74 | ||
75 | if (*n == 0) | |
76 | /* Ending NUL */ | |
77 | return -EINVAL; | |
78 | ||
79 | else if (*n == '\\' || *n == '.') { | |
80 | /* Escaped backslash or dot */ | |
f7455baa LP |
81 | |
82 | if (d) | |
83 | *(d++) = *n; | |
74b2466e LP |
84 | sz--; |
85 | r++; | |
f7455baa | 86 | n++; |
74b2466e LP |
87 | |
88 | } else if (n[0] >= '0' && n[0] <= '9') { | |
89 | unsigned k; | |
90 | ||
91 | /* Escaped literal ASCII character */ | |
92 | ||
93 | if (!(n[1] >= '0' && n[1] <= '9') || | |
94 | !(n[2] >= '0' && n[2] <= '9')) | |
95 | return -EINVAL; | |
96 | ||
97 | k = ((unsigned) (n[0] - '0') * 100) + | |
98 | ((unsigned) (n[1] - '0') * 10) + | |
99 | ((unsigned) (n[2] - '0')); | |
100 | ||
c7feab76 LP |
101 | /* Don't allow anything that doesn't |
102 | * fit in 8bit. Note that we do allow | |
103 | * control characters, as some servers | |
104 | * (e.g. cloudflare) are happy to | |
105 | * generate labels with them | |
106 | * inside. */ | |
107 | if (k > 255) | |
74b2466e LP |
108 | return -EINVAL; |
109 | ||
f7455baa LP |
110 | if (d) |
111 | *(d++) = (char) k; | |
74b2466e LP |
112 | sz--; |
113 | r++; | |
114 | ||
115 | n += 3; | |
116 | } else | |
117 | return -EINVAL; | |
118 | ||
07bed172 | 119 | } else if ((uint8_t) *n >= (uint8_t) ' ' && *n != 127) { |
74b2466e LP |
120 | |
121 | /* Normal character */ | |
f7455baa LP |
122 | |
123 | if (d) | |
124 | *(d++) = *n; | |
74b2466e LP |
125 | sz--; |
126 | r++; | |
f7455baa | 127 | n++; |
74b2466e LP |
128 | } else |
129 | return -EINVAL; | |
130 | } | |
131 | ||
132 | /* Empty label that is not at the end? */ | |
133 | if (r == 0 && *n) | |
134 | return -EINVAL; | |
135 | ||
f7455baa | 136 | if (sz >= 1 && d) |
74b2466e LP |
137 | *d = 0; |
138 | ||
139 | *name = n; | |
140 | return r; | |
141 | } | |
142 | ||
642900d3 TG |
143 | /* @label_terminal: terminal character of a label, updated to point to the terminal character of |
144 | * the previous label (always skipping one dot) or to NULL if there are no more | |
145 | * labels. */ | |
146 | int dns_label_unescape_suffix(const char *name, const char **label_terminal, char *dest, size_t sz) { | |
147 | const char *terminal; | |
148 | int r; | |
149 | ||
150 | assert(name); | |
151 | assert(label_terminal); | |
152 | assert(dest); | |
153 | ||
154 | /* no more labels */ | |
155 | if (!*label_terminal) { | |
156 | if (sz >= 1) | |
157 | *dest = 0; | |
158 | ||
159 | return 0; | |
160 | } | |
161 | ||
56512859 LP |
162 | terminal = *label_terminal; |
163 | assert(*terminal == '.' || *terminal == 0); | |
642900d3 | 164 | |
56512859 LP |
165 | /* Skip current terminal character (and accept domain names ending it ".") */ |
166 | if (*terminal == 0) | |
167 | terminal--; | |
168 | if (terminal >= name && *terminal == '.') | |
169 | terminal--; | |
642900d3 | 170 | |
56512859 | 171 | /* Point name to the last label, and terminal to the preceding terminal symbol (or make it a NULL pointer) */ |
642900d3 TG |
172 | for (;;) { |
173 | if (terminal < name) { | |
56512859 | 174 | /* Reached the first label, so indicate that there are no more */ |
642900d3 TG |
175 | terminal = NULL; |
176 | break; | |
177 | } | |
178 | ||
56512859 | 179 | /* Find the start of the last label */ |
642900d3 TG |
180 | if (*terminal == '.') { |
181 | const char *y; | |
182 | unsigned slashes = 0; | |
183 | ||
184 | for (y = terminal - 1; y >= name && *y == '\\'; y--) | |
185 | slashes ++; | |
186 | ||
187 | if (slashes % 2 == 0) { | |
56512859 | 188 | /* The '.' was not escaped */ |
642900d3 TG |
189 | name = terminal + 1; |
190 | break; | |
191 | } else { | |
192 | terminal = y; | |
193 | continue; | |
194 | } | |
195 | } | |
196 | ||
197 | terminal --; | |
198 | } | |
199 | ||
200 | r = dns_label_unescape(&name, dest, sz); | |
201 | if (r < 0) | |
202 | return r; | |
203 | ||
204 | *label_terminal = terminal; | |
205 | ||
206 | return r; | |
207 | } | |
208 | ||
422baca0 | 209 | int dns_label_escape(const char *p, size_t l, char *dest, size_t sz) { |
74b2466e | 210 | char *q; |
74b2466e | 211 | |
3b37fa73 LP |
212 | /* DNS labels must be between 1 and 63 characters long. A |
213 | * zero-length label does not exist. See RFC 2182, Section | |
214 | * 11. */ | |
215 | ||
216 | if (l <= 0 || l > DNS_LABEL_MAX) | |
1fa65c59 | 217 | return -EINVAL; |
422baca0 | 218 | if (sz < 1) |
37ade128 | 219 | return -ENOBUFS; |
1fa65c59 | 220 | |
422baca0 LP |
221 | assert(p); |
222 | assert(dest); | |
74b2466e | 223 | |
422baca0 | 224 | q = dest; |
74b2466e LP |
225 | while (l > 0) { |
226 | ||
227 | if (*p == '.' || *p == '\\') { | |
228 | ||
3b37fa73 LP |
229 | /* Dot or backslash */ |
230 | ||
422baca0 | 231 | if (sz < 3) |
37ade128 | 232 | return -ENOBUFS; |
422baca0 | 233 | |
74b2466e LP |
234 | *(q++) = '\\'; |
235 | *(q++) = *p; | |
236 | ||
422baca0 LP |
237 | sz -= 2; |
238 | ||
74b2466e LP |
239 | } else if (*p == '_' || |
240 | *p == '-' || | |
241 | (*p >= '0' && *p <= '9') || | |
242 | (*p >= 'a' && *p <= 'z') || | |
243 | (*p >= 'A' && *p <= 'Z')) { | |
244 | ||
245 | /* Proper character */ | |
422baca0 LP |
246 | |
247 | if (sz < 2) | |
37ade128 | 248 | return -ENOBUFS; |
422baca0 | 249 | |
74b2466e | 250 | *(q++) = *p; |
422baca0 LP |
251 | sz -= 1; |
252 | ||
c7feab76 | 253 | } else { |
74b2466e LP |
254 | |
255 | /* Everything else */ | |
422baca0 LP |
256 | |
257 | if (sz < 5) | |
37ade128 | 258 | return -ENOBUFS; |
422baca0 | 259 | |
74b2466e | 260 | *(q++) = '\\'; |
07bed172 LP |
261 | *(q++) = '0' + (char) ((uint8_t) *p / 100); |
262 | *(q++) = '0' + (char) (((uint8_t) *p / 10) % 10); | |
263 | *(q++) = '0' + (char) ((uint8_t) *p % 10); | |
74b2466e | 264 | |
422baca0 LP |
265 | sz -= 4; |
266 | ||
c7feab76 | 267 | } |
74b2466e LP |
268 | |
269 | p++; | |
270 | l--; | |
271 | } | |
272 | ||
273 | *q = 0; | |
422baca0 LP |
274 | return (int) (q - dest); |
275 | } | |
276 | ||
277 | int dns_label_escape_new(const char *p, size_t l, char **ret) { | |
278 | _cleanup_free_ char *s = NULL; | |
279 | int r; | |
280 | ||
281 | assert(p); | |
282 | assert(ret); | |
283 | ||
3b37fa73 | 284 | if (l <= 0 || l > DNS_LABEL_MAX) |
422baca0 LP |
285 | return -EINVAL; |
286 | ||
287 | s = new(char, DNS_LABEL_ESCAPED_MAX); | |
288 | if (!s) | |
289 | return -ENOMEM; | |
290 | ||
291 | r = dns_label_escape(p, l, s, DNS_LABEL_ESCAPED_MAX); | |
292 | if (r < 0) | |
293 | return r; | |
294 | ||
74b2466e | 295 | *ret = s; |
74b2466e LP |
296 | s = NULL; |
297 | ||
298 | return r; | |
299 | } | |
300 | ||
bdf10b5b LP |
301 | int dns_label_apply_idna(const char *encoded, size_t encoded_size, char *decoded, size_t decoded_max) { |
302 | #ifdef HAVE_LIBIDN | |
303 | _cleanup_free_ uint32_t *input = NULL; | |
3b37fa73 | 304 | size_t input_size, l; |
bdf10b5b LP |
305 | const char *p; |
306 | bool contains_8bit = false; | |
3b37fa73 | 307 | char buffer[DNS_LABEL_MAX+1]; |
bdf10b5b LP |
308 | |
309 | assert(encoded); | |
310 | assert(decoded); | |
3b37fa73 LP |
311 | |
312 | /* Converts an U-label into an A-label */ | |
bdf10b5b LP |
313 | |
314 | if (encoded_size <= 0) | |
3b37fa73 | 315 | return -EINVAL; |
bdf10b5b LP |
316 | |
317 | for (p = encoded; p < encoded + encoded_size; p++) | |
318 | if ((uint8_t) *p > 127) | |
319 | contains_8bit = true; | |
320 | ||
3b37fa73 LP |
321 | if (!contains_8bit) { |
322 | if (encoded_size > DNS_LABEL_MAX) | |
323 | return -EINVAL; | |
324 | ||
bdf10b5b | 325 | return 0; |
3b37fa73 | 326 | } |
bdf10b5b LP |
327 | |
328 | input = stringprep_utf8_to_ucs4(encoded, encoded_size, &input_size); | |
329 | if (!input) | |
330 | return -ENOMEM; | |
331 | ||
3b37fa73 LP |
332 | if (idna_to_ascii_4i(input, input_size, buffer, 0) != 0) |
333 | return -EINVAL; | |
334 | ||
335 | l = strlen(buffer); | |
336 | ||
337 | /* Verify that the the result is not longer than one DNS label. */ | |
338 | if (l <= 0 || l > DNS_LABEL_MAX) | |
bdf10b5b | 339 | return -EINVAL; |
3b37fa73 | 340 | if (l > decoded_max) |
37ade128 | 341 | return -ENOBUFS; |
3b37fa73 LP |
342 | |
343 | memcpy(decoded, buffer, l); | |
bdf10b5b | 344 | |
3b37fa73 LP |
345 | /* If there's room, append a trailing NUL byte, but only then */ |
346 | if (decoded_max > l) | |
347 | decoded[l] = 0; | |
348 | ||
349 | return (int) l; | |
bdf10b5b LP |
350 | #else |
351 | return 0; | |
352 | #endif | |
353 | } | |
354 | ||
355 | int dns_label_undo_idna(const char *encoded, size_t encoded_size, char *decoded, size_t decoded_max) { | |
356 | #ifdef HAVE_LIBIDN | |
357 | size_t input_size, output_size; | |
358 | _cleanup_free_ uint32_t *input = NULL; | |
359 | _cleanup_free_ char *result = NULL; | |
360 | uint32_t *output = NULL; | |
361 | size_t w; | |
362 | ||
3b37fa73 | 363 | /* To be invoked after unescaping. Converts an A-label into an U-label. */ |
bdf10b5b LP |
364 | |
365 | assert(encoded); | |
366 | assert(decoded); | |
367 | ||
3b37fa73 LP |
368 | if (encoded_size <= 0 || encoded_size > DNS_LABEL_MAX) |
369 | return -EINVAL; | |
370 | ||
bdf10b5b LP |
371 | if (encoded_size < sizeof(IDNA_ACE_PREFIX)-1) |
372 | return 0; | |
373 | ||
374 | if (memcmp(encoded, IDNA_ACE_PREFIX, sizeof(IDNA_ACE_PREFIX) -1) != 0) | |
375 | return 0; | |
376 | ||
377 | input = stringprep_utf8_to_ucs4(encoded, encoded_size, &input_size); | |
378 | if (!input) | |
379 | return -ENOMEM; | |
380 | ||
381 | output_size = input_size; | |
382 | output = newa(uint32_t, output_size); | |
383 | ||
384 | idna_to_unicode_44i(input, input_size, output, &output_size, 0); | |
385 | ||
386 | result = stringprep_ucs4_to_utf8(output, output_size, NULL, &w); | |
387 | if (!result) | |
388 | return -ENOMEM; | |
389 | if (w <= 0) | |
bdf10b5b | 390 | return -EINVAL; |
3b37fa73 | 391 | if (w > decoded_max) |
37ade128 | 392 | return -ENOBUFS; |
3b37fa73 LP |
393 | |
394 | memcpy(decoded, result, w); | |
395 | ||
396 | /* Append trailing NUL byte if there's space, but only then. */ | |
397 | if (decoded_max > w) | |
398 | decoded[w] = 0; | |
bdf10b5b | 399 | |
bdf10b5b LP |
400 | return w; |
401 | #else | |
402 | return 0; | |
403 | #endif | |
404 | } | |
405 | ||
9ca45586 | 406 | int dns_name_concat(const char *a, const char *b, char **_ret) { |
74b2466e LP |
407 | _cleanup_free_ char *ret = NULL; |
408 | size_t n = 0, allocated = 0; | |
9ca45586 | 409 | const char *p = a; |
74b2466e LP |
410 | bool first = true; |
411 | int r; | |
412 | ||
9ca45586 | 413 | assert(a); |
74b2466e LP |
414 | |
415 | for (;;) { | |
74b2466e | 416 | char label[DNS_LABEL_MAX]; |
bdf10b5b | 417 | int k; |
74b2466e LP |
418 | |
419 | r = dns_label_unescape(&p, label, sizeof(label)); | |
420 | if (r < 0) | |
421 | return r; | |
422 | if (r == 0) { | |
423 | if (*p != 0) | |
424 | return -EINVAL; | |
9ca45586 LP |
425 | |
426 | if (b) { | |
427 | /* Now continue with the second string, if there is one */ | |
428 | p = b; | |
429 | b = NULL; | |
430 | continue; | |
431 | } | |
432 | ||
74b2466e LP |
433 | break; |
434 | } | |
435 | ||
bdf10b5b LP |
436 | k = dns_label_undo_idna(label, r, label, sizeof(label)); |
437 | if (k < 0) | |
438 | return k; | |
439 | if (k > 0) | |
440 | r = k; | |
441 | ||
9ca45586 | 442 | if (_ret) { |
422baca0 | 443 | if (!GREEDY_REALLOC(ret, allocated, n + !first + DNS_LABEL_ESCAPED_MAX)) |
9ca45586 | 444 | return -ENOMEM; |
74b2466e | 445 | |
422baca0 LP |
446 | r = dns_label_escape(label, r, ret + n + !first, DNS_LABEL_ESCAPED_MAX); |
447 | if (r < 0) | |
448 | return r; | |
449 | ||
9ca45586 | 450 | if (!first) |
422baca0 LP |
451 | ret[n] = '.'; |
452 | } else { | |
453 | char escaped[DNS_LABEL_ESCAPED_MAX]; | |
9ca45586 | 454 | |
422baca0 LP |
455 | r = dns_label_escape(label, r, escaped, sizeof(escaped)); |
456 | if (r < 0) | |
457 | return r; | |
9ca45586 | 458 | } |
74b2466e | 459 | |
422baca0 LP |
460 | if (!first) |
461 | n++; | |
462 | else | |
463 | first = false; | |
464 | ||
74b2466e LP |
465 | n += r; |
466 | } | |
467 | ||
1dfbf000 LP |
468 | if (n > DNS_HOSTNAME_MAX) |
469 | return -EINVAL; | |
470 | ||
7b9f7afc | 471 | if (_ret) { |
9ca45586 LP |
472 | if (!GREEDY_REALLOC(ret, allocated, n + 1)) |
473 | return -ENOMEM; | |
474 | ||
475 | ret[n] = 0; | |
7b9f7afc LP |
476 | *_ret = ret; |
477 | ret = NULL; | |
478 | } | |
74b2466e LP |
479 | |
480 | return 0; | |
481 | } | |
482 | ||
b826ab58 | 483 | void dns_name_hash_func(const void *s, struct siphash *state) { |
74b2466e | 484 | const char *p = s; |
74b2466e LP |
485 | int r; |
486 | ||
487 | assert(p); | |
488 | ||
d12315a4 | 489 | for (;;) { |
74b2466e | 490 | char label[DNS_LABEL_MAX+1]; |
bdf10b5b | 491 | int k; |
74b2466e LP |
492 | |
493 | r = dns_label_unescape(&p, label, sizeof(label)); | |
494 | if (r < 0) | |
495 | break; | |
d12315a4 LP |
496 | if (r == 0) |
497 | break; | |
74b2466e | 498 | |
bdf10b5b LP |
499 | k = dns_label_undo_idna(label, r, label, sizeof(label)); |
500 | if (k < 0) | |
7da40fc1 | 501 | break; |
bdf10b5b LP |
502 | if (k > 0) |
503 | r = k; | |
504 | ||
509eddd2 LP |
505 | ascii_strlower_n(label, r); |
506 | siphash24_compress(label, r, state); | |
74b2466e | 507 | } |
1e2527a6 TG |
508 | |
509 | /* enforce that all names are terminated by the empty label */ | |
510 | string_hash_func("", state); | |
74b2466e LP |
511 | } |
512 | ||
513 | int dns_name_compare_func(const void *a, const void *b) { | |
5dfd7011 | 514 | const char *x, *y; |
bdf10b5b | 515 | int r, q, k, w; |
74b2466e LP |
516 | |
517 | assert(a); | |
518 | assert(b); | |
519 | ||
5dfd7011 TG |
520 | x = (const char *) a + strlen(a); |
521 | y = (const char *) b + strlen(b); | |
522 | ||
74b2466e LP |
523 | for (;;) { |
524 | char la[DNS_LABEL_MAX+1], lb[DNS_LABEL_MAX+1]; | |
525 | ||
5dfd7011 | 526 | if (x == NULL && y == NULL) |
74b2466e LP |
527 | return 0; |
528 | ||
5dfd7011 TG |
529 | r = dns_label_unescape_suffix(a, &x, la, sizeof(la)); |
530 | q = dns_label_unescape_suffix(b, &y, lb, sizeof(lb)); | |
74b2466e LP |
531 | if (r < 0 || q < 0) |
532 | return r - q; | |
533 | ||
bdf10b5b LP |
534 | k = dns_label_undo_idna(la, r, la, sizeof(la)); |
535 | w = dns_label_undo_idna(lb, q, lb, sizeof(lb)); | |
536 | if (k < 0 || w < 0) | |
537 | return k - w; | |
538 | if (k > 0) | |
539 | r = k; | |
540 | if (w > 0) | |
735323d9 | 541 | q = w; |
bdf10b5b | 542 | |
74b2466e LP |
543 | la[r] = lb[q] = 0; |
544 | r = strcasecmp(la, lb); | |
545 | if (r != 0) | |
546 | return r; | |
547 | } | |
548 | } | |
549 | ||
d5099efc MS |
550 | const struct hash_ops dns_name_hash_ops = { |
551 | .hash = dns_name_hash_func, | |
552 | .compare = dns_name_compare_func | |
553 | }; | |
554 | ||
74b2466e | 555 | int dns_name_equal(const char *x, const char *y) { |
bdf10b5b | 556 | int r, q, k, w; |
74b2466e LP |
557 | |
558 | assert(x); | |
559 | assert(y); | |
560 | ||
561 | for (;;) { | |
562 | char la[DNS_LABEL_MAX+1], lb[DNS_LABEL_MAX+1]; | |
563 | ||
564 | if (*x == 0 && *y == 0) | |
565 | return true; | |
566 | ||
567 | r = dns_label_unescape(&x, la, sizeof(la)); | |
568 | if (r < 0) | |
569 | return r; | |
3b37fa73 LP |
570 | if (r > 0) { |
571 | k = dns_label_undo_idna(la, r, la, sizeof(la)); | |
572 | if (k < 0) | |
573 | return k; | |
574 | if (k > 0) | |
575 | r = k; | |
576 | } | |
bdf10b5b | 577 | |
74b2466e LP |
578 | q = dns_label_unescape(&y, lb, sizeof(lb)); |
579 | if (q < 0) | |
580 | return q; | |
3b37fa73 LP |
581 | if (q > 0) { |
582 | w = dns_label_undo_idna(lb, q, lb, sizeof(lb)); | |
583 | if (w < 0) | |
584 | return w; | |
585 | if (w > 0) | |
586 | q = w; | |
587 | } | |
588 | ||
589 | /* If one name had fewer labels than the other, this | |
590 | * will show up as empty label here, which the | |
591 | * strcasecmp() below will properly consider different | |
592 | * from a non-empty label. */ | |
74b2466e LP |
593 | |
594 | la[r] = lb[q] = 0; | |
3b37fa73 | 595 | if (strcasecmp(la, lb) != 0) |
74b2466e LP |
596 | return false; |
597 | } | |
598 | } | |
599 | ||
600 | int dns_name_endswith(const char *name, const char *suffix) { | |
601 | const char *n, *s, *saved_n = NULL; | |
bdf10b5b | 602 | int r, q, k, w; |
74b2466e LP |
603 | |
604 | assert(name); | |
605 | assert(suffix); | |
606 | ||
607 | n = name; | |
608 | s = suffix; | |
609 | ||
610 | for (;;) { | |
611 | char ln[DNS_LABEL_MAX+1], ls[DNS_LABEL_MAX+1]; | |
612 | ||
613 | r = dns_label_unescape(&n, ln, sizeof(ln)); | |
614 | if (r < 0) | |
615 | return r; | |
3b37fa73 LP |
616 | if (r > 0) { |
617 | k = dns_label_undo_idna(ln, r, ln, sizeof(ln)); | |
618 | if (k < 0) | |
619 | return k; | |
620 | if (k > 0) | |
621 | r = k; | |
622 | } | |
74b2466e LP |
623 | |
624 | if (!saved_n) | |
625 | saved_n = n; | |
626 | ||
627 | q = dns_label_unescape(&s, ls, sizeof(ls)); | |
be754d54 LP |
628 | if (q < 0) |
629 | return q; | |
3b37fa73 LP |
630 | if (q > 0) { |
631 | w = dns_label_undo_idna(ls, q, ls, sizeof(ls)); | |
632 | if (w < 0) | |
633 | return w; | |
634 | if (w > 0) | |
635 | q = w; | |
636 | } | |
74b2466e LP |
637 | |
638 | if (r == 0 && q == 0) | |
639 | return true; | |
640 | if (r == 0 && saved_n == n) | |
641 | return false; | |
642 | ||
643 | ln[r] = ls[q] = 0; | |
644 | ||
645 | if (r != q || strcasecmp(ln, ls)) { | |
646 | ||
647 | /* Not the same, let's jump back, and try with the next label again */ | |
648 | s = suffix; | |
649 | n = saved_n; | |
650 | saved_n = NULL; | |
651 | } | |
652 | } | |
653 | } | |
654 | ||
58db254a LP |
655 | int dns_name_change_suffix(const char *name, const char *old_suffix, const char *new_suffix, char **ret) { |
656 | const char *n, *s, *saved_before = NULL, *saved_after = NULL, *prefix; | |
657 | int r, q, k, w; | |
658 | ||
659 | assert(name); | |
660 | assert(old_suffix); | |
661 | assert(new_suffix); | |
662 | assert(ret); | |
663 | ||
664 | n = name; | |
665 | s = old_suffix; | |
666 | ||
667 | for (;;) { | |
668 | char ln[DNS_LABEL_MAX+1], ls[DNS_LABEL_MAX+1]; | |
669 | ||
670 | if (!saved_before) | |
671 | saved_before = n; | |
672 | ||
673 | r = dns_label_unescape(&n, ln, sizeof(ln)); | |
674 | if (r < 0) | |
675 | return r; | |
3b37fa73 LP |
676 | if (r > 0) { |
677 | k = dns_label_undo_idna(ln, r, ln, sizeof(ln)); | |
678 | if (k < 0) | |
679 | return k; | |
680 | if (k > 0) | |
681 | r = k; | |
682 | } | |
58db254a LP |
683 | |
684 | if (!saved_after) | |
685 | saved_after = n; | |
686 | ||
687 | q = dns_label_unescape(&s, ls, sizeof(ls)); | |
688 | if (q < 0) | |
689 | return q; | |
3b37fa73 LP |
690 | if (q > 0) { |
691 | w = dns_label_undo_idna(ls, q, ls, sizeof(ls)); | |
692 | if (w < 0) | |
693 | return w; | |
694 | if (w > 0) | |
695 | q = w; | |
696 | } | |
58db254a LP |
697 | |
698 | if (r == 0 && q == 0) | |
699 | break; | |
700 | if (r == 0 && saved_after == n) { | |
701 | *ret = NULL; /* doesn't match */ | |
702 | return 0; | |
703 | } | |
704 | ||
705 | ln[r] = ls[q] = 0; | |
706 | ||
707 | if (r != q || strcasecmp(ln, ls)) { | |
708 | ||
709 | /* Not the same, let's jump back, and try with the next label again */ | |
710 | s = old_suffix; | |
711 | n = saved_after; | |
712 | saved_after = saved_before = NULL; | |
713 | } | |
714 | } | |
715 | ||
716 | /* Found it! Now generate the new name */ | |
717 | prefix = strndupa(name, saved_before - name); | |
718 | ||
719 | r = dns_name_concat(prefix, new_suffix, ret); | |
720 | if (r < 0) | |
721 | return r; | |
722 | ||
723 | return 1; | |
724 | } | |
725 | ||
ae72b22c TG |
726 | int dns_name_between(const char *a, const char *b, const char *c) { |
727 | int n; | |
728 | ||
729 | /* Determine if b is strictly greater than a and strictly smaller than c. | |
730 | We consider the order of names to be circular, so that if a is | |
731 | strictly greater than c, we consider b to be between them if it is | |
732 | either greater than a or smaller than c. This is how the canonical | |
733 | DNS name order used in NSEC records work. */ | |
734 | ||
735 | n = dns_name_compare_func(a, c); | |
736 | if (n == 0) | |
737 | return -EINVAL; | |
738 | else if (n < 0) | |
739 | /* a<---b--->c */ | |
740 | return dns_name_compare_func(a, b) < 0 && | |
741 | dns_name_compare_func(b, c) < 0; | |
742 | else | |
743 | /* <--b--c a--b--> */ | |
744 | return dns_name_compare_func(b, c) < 0 || | |
745 | dns_name_compare_func(a, b) < 0; | |
746 | } | |
747 | ||
74b2466e LP |
748 | int dns_name_reverse(int family, const union in_addr_union *a, char **ret) { |
749 | const uint8_t *p; | |
750 | int r; | |
751 | ||
752 | assert(a); | |
753 | assert(ret); | |
754 | ||
755 | p = (const uint8_t*) a; | |
756 | ||
757 | if (family == AF_INET) | |
758 | r = asprintf(ret, "%u.%u.%u.%u.in-addr.arpa", p[3], p[2], p[1], p[0]); | |
759 | else if (family == AF_INET6) | |
3fe1169f LP |
760 | r = asprintf(ret, "%c.%c.%c.%c.%c.%c.%c.%c.%c.%c.%c.%c.%c.%c.%c.%c.%c.%c.%c.%c.%c.%c.%c.%c.%c.%c.%c.%c.%c.%c.%c.%c.ip6.arpa", |
761 | hexchar(p[15] & 0xF), hexchar(p[15] >> 4), hexchar(p[14] & 0xF), hexchar(p[14] >> 4), | |
762 | hexchar(p[13] & 0xF), hexchar(p[13] >> 4), hexchar(p[12] & 0xF), hexchar(p[12] >> 4), | |
763 | hexchar(p[11] & 0xF), hexchar(p[11] >> 4), hexchar(p[10] & 0xF), hexchar(p[10] >> 4), | |
764 | hexchar(p[ 9] & 0xF), hexchar(p[ 9] >> 4), hexchar(p[ 8] & 0xF), hexchar(p[ 8] >> 4), | |
765 | hexchar(p[ 7] & 0xF), hexchar(p[ 7] >> 4), hexchar(p[ 6] & 0xF), hexchar(p[ 6] >> 4), | |
766 | hexchar(p[ 5] & 0xF), hexchar(p[ 5] >> 4), hexchar(p[ 4] & 0xF), hexchar(p[ 4] >> 4), | |
767 | hexchar(p[ 3] & 0xF), hexchar(p[ 3] >> 4), hexchar(p[ 2] & 0xF), hexchar(p[ 2] >> 4), | |
768 | hexchar(p[ 1] & 0xF), hexchar(p[ 1] >> 4), hexchar(p[ 0] & 0xF), hexchar(p[ 0] >> 4)); | |
74b2466e LP |
769 | else |
770 | return -EAFNOSUPPORT; | |
771 | if (r < 0) | |
772 | return -ENOMEM; | |
773 | ||
774 | return 0; | |
775 | } | |
776 | ||
b914e211 LP |
777 | int dns_name_address(const char *p, int *family, union in_addr_union *address) { |
778 | int r; | |
779 | ||
780 | assert(p); | |
781 | assert(family); | |
782 | assert(address); | |
783 | ||
784 | r = dns_name_endswith(p, "in-addr.arpa"); | |
785 | if (r < 0) | |
786 | return r; | |
787 | if (r > 0) { | |
788 | uint8_t a[4]; | |
789 | unsigned i; | |
790 | ||
791 | for (i = 0; i < ELEMENTSOF(a); i++) { | |
792 | char label[DNS_LABEL_MAX+1]; | |
793 | ||
794 | r = dns_label_unescape(&p, label, sizeof(label)); | |
795 | if (r < 0) | |
796 | return r; | |
797 | if (r == 0) | |
798 | return -EINVAL; | |
799 | if (r > 3) | |
800 | return -EINVAL; | |
801 | ||
802 | r = safe_atou8(label, &a[i]); | |
803 | if (r < 0) | |
804 | return r; | |
805 | } | |
806 | ||
807 | r = dns_name_equal(p, "in-addr.arpa"); | |
808 | if (r <= 0) | |
809 | return r; | |
810 | ||
811 | *family = AF_INET; | |
812 | address->in.s_addr = htobe32(((uint32_t) a[3] << 24) | | |
813 | ((uint32_t) a[2] << 16) | | |
814 | ((uint32_t) a[1] << 8) | | |
815 | (uint32_t) a[0]); | |
816 | ||
817 | return 1; | |
818 | } | |
819 | ||
820 | r = dns_name_endswith(p, "ip6.arpa"); | |
821 | if (r < 0) | |
822 | return r; | |
823 | if (r > 0) { | |
824 | struct in6_addr a; | |
825 | unsigned i; | |
826 | ||
827 | for (i = 0; i < ELEMENTSOF(a.s6_addr); i++) { | |
828 | char label[DNS_LABEL_MAX+1]; | |
829 | int x, y; | |
830 | ||
831 | r = dns_label_unescape(&p, label, sizeof(label)); | |
832 | if (r <= 0) | |
833 | return r; | |
834 | if (r != 1) | |
835 | return -EINVAL; | |
836 | x = unhexchar(label[0]); | |
837 | if (x < 0) | |
838 | return -EINVAL; | |
839 | ||
840 | r = dns_label_unescape(&p, label, sizeof(label)); | |
841 | if (r <= 0) | |
842 | return r; | |
843 | if (r != 1) | |
844 | return -EINVAL; | |
845 | y = unhexchar(label[0]); | |
846 | if (y < 0) | |
847 | return -EINVAL; | |
848 | ||
849 | a.s6_addr[ELEMENTSOF(a.s6_addr) - i - 1] = (uint8_t) y << 4 | (uint8_t) x; | |
850 | } | |
851 | ||
852 | r = dns_name_equal(p, "ip6.arpa"); | |
853 | if (r <= 0) | |
854 | return r; | |
855 | ||
856 | *family = AF_INET6; | |
857 | address->in6 = a; | |
858 | return 1; | |
859 | } | |
860 | ||
861 | return 0; | |
862 | } | |
863 | ||
dc477e73 | 864 | bool dns_name_is_root(const char *name) { |
74b2466e LP |
865 | |
866 | assert(name); | |
867 | ||
dc477e73 LP |
868 | /* There are exactly two ways to encode the root domain name: |
869 | * as empty string, or with a single dot. */ | |
74b2466e | 870 | |
dc477e73 | 871 | return STR_IN_SET(name, "", "."); |
74b2466e LP |
872 | } |
873 | ||
dc477e73 | 874 | bool dns_name_is_single_label(const char *name) { |
74b2466e LP |
875 | char label[DNS_LABEL_MAX+1]; |
876 | int r; | |
877 | ||
878 | assert(name); | |
879 | ||
880 | r = dns_label_unescape(&name, label, sizeof(label)); | |
dc477e73 LP |
881 | if (r <= 0) |
882 | return false; | |
74b2466e | 883 | |
dc477e73 | 884 | return dns_name_is_root(name); |
74b2466e | 885 | } |
54adabf7 | 886 | |
50dee79b | 887 | /* Encode a domain name according to RFC 1035 Section 3.1, without compression */ |
3cd03457 | 888 | int dns_name_to_wire_format(const char *domain, uint8_t *buffer, size_t len, bool canonical) { |
c6cefd13 | 889 | uint8_t *label_length, *out; |
54adabf7 BG |
890 | int r; |
891 | ||
c6cefd13 LP |
892 | assert(domain); |
893 | assert(buffer); | |
54adabf7 BG |
894 | |
895 | out = buffer; | |
896 | ||
897 | do { | |
50dee79b | 898 | /* Reserve a byte for label length */ |
c6cefd13 | 899 | if (len <= 0) |
54adabf7 BG |
900 | return -ENOBUFS; |
901 | len--; | |
902 | label_length = out; | |
903 | out++; | |
904 | ||
50dee79b LP |
905 | /* Convert and copy a single label. Note that |
906 | * dns_label_unescape() returns 0 when it hits the end | |
907 | * of the domain name, which we rely on here to encode | |
908 | * the trailing NUL byte. */ | |
54adabf7 BG |
909 | r = dns_label_unescape(&domain, (char *) out, len); |
910 | if (r < 0) | |
911 | return r; | |
912 | ||
b577e3d5 LP |
913 | /* Optionally, output the name in DNSSEC canonical |
914 | * format, as described in RFC 4034, section 6.2. Or | |
915 | * in other words: in lower-case. */ | |
916 | if (canonical) | |
917 | ascii_strlower_n((char*) out, (size_t) r); | |
3cd03457 | 918 | |
50dee79b | 919 | /* Fill label length, move forward */ |
54adabf7 BG |
920 | *label_length = r; |
921 | out += r; | |
922 | len -= r; | |
50dee79b | 923 | |
54adabf7 BG |
924 | } while (r != 0); |
925 | ||
50dee79b LP |
926 | /* Verify the maximum size of the encoded name. The trailing |
927 | * dot + NUL byte account are included this time, hence | |
928 | * compare against DNS_HOSTNAME_MAX + 2 (which is 255) this | |
929 | * time. */ | |
930 | if (out - buffer > DNS_HOSTNAME_MAX + 2) | |
931 | return -EINVAL; | |
932 | ||
54adabf7 BG |
933 | return out - buffer; |
934 | } | |
0a49b6b6 | 935 | |
0e8eedbb LP |
936 | static bool srv_type_label_is_valid(const char *label, size_t n) { |
937 | size_t k; | |
938 | ||
939 | assert(label); | |
940 | ||
941 | if (n < 2) /* Label needs to be at least 2 chars long */ | |
942 | return false; | |
943 | ||
944 | if (label[0] != '_') /* First label char needs to be underscore */ | |
945 | return false; | |
946 | ||
947 | /* Second char must be a letter */ | |
948 | if (!(label[1] >= 'A' && label[1] <= 'Z') && | |
949 | !(label[1] >= 'a' && label[1] <= 'z')) | |
950 | return false; | |
951 | ||
952 | /* Third and further chars must be alphanumeric or a hyphen */ | |
953 | for (k = 2; k < n; k++) { | |
954 | if (!(label[k] >= 'A' && label[k] <= 'Z') && | |
955 | !(label[k] >= 'a' && label[k] <= 'z') && | |
956 | !(label[k] >= '0' && label[k] <= '9') && | |
957 | label[k] != '-') | |
958 | return false; | |
959 | } | |
960 | ||
961 | return true; | |
962 | } | |
963 | ||
7e8131e9 | 964 | bool dns_srv_type_is_valid(const char *name) { |
0a49b6b6 LP |
965 | unsigned c = 0; |
966 | int r; | |
967 | ||
968 | if (!name) | |
7e8131e9 | 969 | return false; |
0a49b6b6 LP |
970 | |
971 | for (;;) { | |
972 | char label[DNS_LABEL_MAX]; | |
0a49b6b6 LP |
973 | |
974 | /* This more or less implements RFC 6335, Section 5.1 */ | |
975 | ||
976 | r = dns_label_unescape(&name, label, sizeof(label)); | |
0a49b6b6 | 977 | if (r < 0) |
7e8131e9 | 978 | return false; |
0a49b6b6 | 979 | if (r == 0) |
0e8eedbb | 980 | break; |
0a49b6b6 | 981 | |
0e8eedbb | 982 | if (c >= 2) |
7e8131e9 | 983 | return false; |
0a49b6b6 | 984 | |
0e8eedbb | 985 | if (!srv_type_label_is_valid(label, r)) |
7e8131e9 | 986 | return false; |
0a49b6b6 LP |
987 | |
988 | c++; | |
989 | } | |
0e8eedbb LP |
990 | |
991 | return c == 2; /* exactly two labels */ | |
0a49b6b6 LP |
992 | } |
993 | ||
994 | bool dns_service_name_is_valid(const char *name) { | |
995 | size_t l; | |
996 | ||
997 | /* This more or less implements RFC 6763, Section 4.1.1 */ | |
998 | ||
999 | if (!name) | |
1000 | return false; | |
1001 | ||
1002 | if (!utf8_is_valid(name)) | |
1003 | return false; | |
1004 | ||
1005 | if (string_has_cc(name, NULL)) | |
1006 | return false; | |
1007 | ||
1008 | l = strlen(name); | |
1009 | if (l <= 0) | |
1010 | return false; | |
1011 | if (l > 63) | |
1012 | return false; | |
1013 | ||
1014 | return true; | |
1015 | } | |
0e8eedbb LP |
1016 | |
1017 | int dns_service_join(const char *name, const char *type, const char *domain, char **ret) { | |
422baca0 LP |
1018 | char escaped[DNS_LABEL_ESCAPED_MAX]; |
1019 | _cleanup_free_ char *n = NULL; | |
0e8eedbb LP |
1020 | int r; |
1021 | ||
1022 | assert(type); | |
1023 | assert(domain); | |
1024 | assert(ret); | |
1025 | ||
7e8131e9 | 1026 | if (!dns_srv_type_is_valid(type)) |
0e8eedbb LP |
1027 | return -EINVAL; |
1028 | ||
1029 | if (!name) | |
1030 | return dns_name_concat(type, domain, ret); | |
1031 | ||
1032 | if (!dns_service_name_is_valid(name)) | |
1033 | return -EINVAL; | |
1034 | ||
422baca0 | 1035 | r = dns_label_escape(name, strlen(name), escaped, sizeof(escaped)); |
0e8eedbb LP |
1036 | if (r < 0) |
1037 | return r; | |
1038 | ||
1039 | r = dns_name_concat(type, domain, &n); | |
1040 | if (r < 0) | |
1041 | return r; | |
1042 | ||
1043 | return dns_name_concat(escaped, n, ret); | |
1044 | } | |
1045 | ||
1046 | static bool dns_service_name_label_is_valid(const char *label, size_t n) { | |
1047 | char *s; | |
1048 | ||
1049 | assert(label); | |
1050 | ||
1051 | if (memchr(label, 0, n)) | |
1052 | return false; | |
1053 | ||
1054 | s = strndupa(label, n); | |
1055 | return dns_service_name_is_valid(s); | |
1056 | } | |
1057 | ||
1058 | int dns_service_split(const char *joined, char **_name, char **_type, char **_domain) { | |
1059 | _cleanup_free_ char *name = NULL, *type = NULL, *domain = NULL; | |
1060 | const char *p = joined, *q = NULL, *d = NULL; | |
1061 | char a[DNS_LABEL_MAX], b[DNS_LABEL_MAX], c[DNS_LABEL_MAX]; | |
1062 | int an, bn, cn, r; | |
1063 | unsigned x = 0; | |
1064 | ||
1065 | assert(joined); | |
1066 | ||
1067 | /* Get first label from the full name */ | |
1068 | an = dns_label_unescape(&p, a, sizeof(a)); | |
1069 | if (an < 0) | |
1070 | return an; | |
1071 | ||
1072 | if (an > 0) { | |
1073 | x++; | |
1074 | ||
1075 | /* If there was a first label, try to get the second one */ | |
1076 | bn = dns_label_unescape(&p, b, sizeof(b)); | |
1077 | if (bn < 0) | |
1078 | return bn; | |
1079 | ||
1080 | if (bn > 0) { | |
1081 | x++; | |
1082 | ||
1083 | /* If there was a second label, try to get the third one */ | |
1084 | q = p; | |
1085 | cn = dns_label_unescape(&p, c, sizeof(c)); | |
1086 | if (cn < 0) | |
1087 | return cn; | |
1088 | ||
1089 | if (cn > 0) | |
1090 | x++; | |
1091 | } else | |
1092 | cn = 0; | |
1093 | } else | |
1094 | an = 0; | |
1095 | ||
1096 | if (x >= 2 && srv_type_label_is_valid(b, bn)) { | |
1097 | ||
1098 | if (x >= 3 && srv_type_label_is_valid(c, cn)) { | |
1099 | ||
1100 | if (dns_service_name_label_is_valid(a, an)) { | |
1101 | ||
1102 | /* OK, got <name> . <type> . <type2> . <domain> */ | |
1103 | ||
1104 | name = strndup(a, an); | |
1105 | if (!name) | |
1106 | return -ENOMEM; | |
1107 | ||
1108 | type = new(char, bn+1+cn+1); | |
1109 | if (!type) | |
1110 | return -ENOMEM; | |
1111 | strcpy(stpcpy(stpcpy(type, b), "."), c); | |
1112 | ||
1113 | d = p; | |
1114 | goto finish; | |
1115 | } | |
1116 | ||
1117 | } else if (srv_type_label_is_valid(a, an)) { | |
1118 | ||
1119 | /* OK, got <type> . <type2> . <domain> */ | |
1120 | ||
1121 | name = NULL; | |
1122 | ||
1123 | type = new(char, an+1+bn+1); | |
1124 | if (!type) | |
1125 | return -ENOMEM; | |
1126 | strcpy(stpcpy(stpcpy(type, a), "."), b); | |
1127 | ||
1128 | d = q; | |
1129 | goto finish; | |
1130 | } | |
1131 | } | |
1132 | ||
1133 | name = NULL; | |
1134 | type = NULL; | |
1135 | d = joined; | |
1136 | ||
1137 | finish: | |
1138 | r = dns_name_normalize(d, &domain); | |
1139 | if (r < 0) | |
1140 | return r; | |
1141 | ||
1142 | if (_domain) { | |
1143 | *_domain = domain; | |
1144 | domain = NULL; | |
1145 | } | |
1146 | ||
1147 | if (_type) { | |
1148 | *_type = type; | |
1149 | type = NULL; | |
1150 | } | |
1151 | ||
1152 | if (_name) { | |
1153 | *_name = name; | |
1154 | name = NULL; | |
1155 | } | |
1156 | ||
1157 | return 0; | |
1158 | } | |
e7ff0e0b LP |
1159 | |
1160 | int dns_name_suffix(const char *name, unsigned n_labels, const char **ret) { | |
1161 | const char* labels[DNS_N_LABELS_MAX+1]; | |
1162 | unsigned n = 0; | |
1163 | const char *p; | |
1164 | int r; | |
1165 | ||
1166 | assert(name); | |
1167 | assert(ret); | |
1168 | ||
1169 | p = name; | |
1170 | for (;;) { | |
1171 | if (n > DNS_N_LABELS_MAX) | |
1172 | return -EINVAL; | |
1173 | ||
1174 | labels[n] = p; | |
1175 | ||
1176 | r = dns_name_parent(&p); | |
1177 | if (r < 0) | |
1178 | return r; | |
1179 | if (r == 0) | |
1180 | break; | |
1181 | ||
1182 | n++; | |
1183 | } | |
1184 | ||
1185 | if (n < n_labels) | |
1186 | return -EINVAL; | |
1187 | ||
1188 | *ret = labels[n - n_labels]; | |
1189 | return (int) (n - n_labels); | |
1190 | } | |
1191 | ||
1192 | int dns_name_count_labels(const char *name) { | |
1193 | unsigned n = 0; | |
1194 | const char *p; | |
1195 | int r; | |
1196 | ||
1197 | assert(name); | |
1198 | ||
1199 | p = name; | |
1200 | for (;;) { | |
1201 | r = dns_name_parent(&p); | |
1202 | if (r < 0) | |
1203 | return r; | |
1204 | if (r == 0) | |
1205 | break; | |
1206 | ||
1207 | if (n >= DNS_N_LABELS_MAX) | |
1208 | return -EINVAL; | |
1209 | ||
1210 | n++; | |
1211 | } | |
1212 | ||
1213 | return (int) n; | |
1214 | } | |
db5b0e92 LP |
1215 | |
1216 | int dns_name_equal_skip(const char *a, unsigned n_labels, const char *b) { | |
1217 | int r; | |
1218 | ||
1219 | assert(a); | |
1220 | assert(b); | |
1221 | ||
1222 | while (n_labels > 0) { | |
1223 | ||
1224 | r = dns_name_parent(&a); | |
1225 | if (r <= 0) | |
1226 | return r; | |
1227 | ||
1228 | n_labels --; | |
1229 | } | |
1230 | ||
1231 | return dns_name_equal(a, b); | |
1232 | } |