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Commit | Line | Data |
---|---|---|
53e1b683 | 1 | /* SPDX-License-Identifier: LGPL-2.1+ */ |
74b2466e | 2 | |
349cc4a5 | 3 | #if HAVE_LIBIDN2 |
87057e24 | 4 | # include <idn2.h> |
349cc4a5 | 5 | #elif HAVE_LIBIDN |
87057e24 ZJS |
6 | # include <idna.h> |
7 | # include <stringprep.h> | |
bdf10b5b LP |
8 | #endif |
9 | ||
a8fbdf54 TA |
10 | #include <endian.h> |
11 | #include <netinet/in.h> | |
12 | #include <stdio.h> | |
13 | #include <string.h> | |
14 | #include <sys/socket.h> | |
15 | ||
b5efdb8a | 16 | #include "alloc-util.h" |
4ad7f276 | 17 | #include "dns-domain.h" |
a8fbdf54 | 18 | #include "hashmap.h" |
e4e73a63 | 19 | #include "hexdecoct.h" |
d65652f1 | 20 | #include "hostname-util.h" |
a8fbdf54 TA |
21 | #include "in-addr-util.h" |
22 | #include "macro.h" | |
6bedfcbb LP |
23 | #include "parse-util.h" |
24 | #include "string-util.h" | |
dc477e73 | 25 | #include "strv.h" |
0a49b6b6 | 26 | #include "utf8.h" |
74b2466e | 27 | |
7470cc4c | 28 | int dns_label_unescape(const char **name, char *dest, size_t sz, DNSLabelFlags flags) { |
74b2466e | 29 | const char *n; |
7470cc4c | 30 | char *d, last_char = 0; |
74b2466e LP |
31 | int r = 0; |
32 | ||
33 | assert(name); | |
34 | assert(*name); | |
74b2466e LP |
35 | |
36 | n = *name; | |
37 | d = dest; | |
38 | ||
39 | for (;;) { | |
7470cc4c ZJS |
40 | if (*n == 0 || *n == '.') { |
41 | if (FLAGS_SET(flags, DNS_LABEL_LDH) && last_char == '-') | |
42 | /* Trailing dash */ | |
43 | return -EINVAL; | |
74b2466e | 44 | |
7470cc4c ZJS |
45 | if (*n == '.') |
46 | n++; | |
74b2466e | 47 | break; |
7470cc4c | 48 | } |
74b2466e | 49 | |
1fa65c59 LP |
50 | if (r >= DNS_LABEL_MAX) |
51 | return -EINVAL; | |
52 | ||
37ade128 LP |
53 | if (sz <= 0) |
54 | return -ENOBUFS; | |
55 | ||
74b2466e LP |
56 | if (*n == '\\') { |
57 | /* Escaped character */ | |
7470cc4c ZJS |
58 | if (FLAGS_SET(flags, DNS_LABEL_NO_ESCAPES)) |
59 | return -EINVAL; | |
74b2466e LP |
60 | |
61 | n++; | |
62 | ||
63 | if (*n == 0) | |
64 | /* Ending NUL */ | |
65 | return -EINVAL; | |
66 | ||
4c701096 | 67 | else if (IN_SET(*n, '\\', '.')) { |
74b2466e | 68 | /* Escaped backslash or dot */ |
f7455baa | 69 | |
7470cc4c ZJS |
70 | if (FLAGS_SET(flags, DNS_LABEL_LDH)) |
71 | return -EINVAL; | |
72 | ||
73 | last_char = *n; | |
f7455baa LP |
74 | if (d) |
75 | *(d++) = *n; | |
74b2466e LP |
76 | sz--; |
77 | r++; | |
f7455baa | 78 | n++; |
74b2466e LP |
79 | |
80 | } else if (n[0] >= '0' && n[0] <= '9') { | |
81 | unsigned k; | |
82 | ||
83 | /* Escaped literal ASCII character */ | |
84 | ||
85 | if (!(n[1] >= '0' && n[1] <= '9') || | |
86 | !(n[2] >= '0' && n[2] <= '9')) | |
87 | return -EINVAL; | |
88 | ||
89 | k = ((unsigned) (n[0] - '0') * 100) + | |
90 | ((unsigned) (n[1] - '0') * 10) + | |
91 | ((unsigned) (n[2] - '0')); | |
92 | ||
c7feab76 LP |
93 | /* Don't allow anything that doesn't |
94 | * fit in 8bit. Note that we do allow | |
95 | * control characters, as some servers | |
96 | * (e.g. cloudflare) are happy to | |
97 | * generate labels with them | |
98 | * inside. */ | |
99 | if (k > 255) | |
74b2466e LP |
100 | return -EINVAL; |
101 | ||
7470cc4c ZJS |
102 | if (FLAGS_SET(flags, DNS_LABEL_LDH) && |
103 | !valid_ldh_char((char) k)) | |
104 | return -EINVAL; | |
105 | ||
106 | last_char = (char) k; | |
f7455baa LP |
107 | if (d) |
108 | *(d++) = (char) k; | |
74b2466e LP |
109 | sz--; |
110 | r++; | |
111 | ||
112 | n += 3; | |
113 | } else | |
114 | return -EINVAL; | |
115 | ||
07bed172 | 116 | } else if ((uint8_t) *n >= (uint8_t) ' ' && *n != 127) { |
74b2466e LP |
117 | |
118 | /* Normal character */ | |
f7455baa | 119 | |
7470cc4c ZJS |
120 | if (FLAGS_SET(flags, DNS_LABEL_LDH)) { |
121 | if (!valid_ldh_char(*n)) | |
122 | return -EINVAL; | |
123 | if (r == 0 && *n == '-') | |
124 | /* Leading dash */ | |
125 | return -EINVAL; | |
126 | } | |
127 | ||
128 | last_char = *n; | |
f7455baa LP |
129 | if (d) |
130 | *(d++) = *n; | |
74b2466e LP |
131 | sz--; |
132 | r++; | |
f7455baa | 133 | n++; |
74b2466e LP |
134 | } else |
135 | return -EINVAL; | |
136 | } | |
137 | ||
138 | /* Empty label that is not at the end? */ | |
139 | if (r == 0 && *n) | |
140 | return -EINVAL; | |
141 | ||
f35c467d MP |
142 | /* More than one trailing dot? */ |
143 | if (*n == '.') | |
144 | return -EINVAL; | |
145 | ||
f7455baa | 146 | if (sz >= 1 && d) |
74b2466e LP |
147 | *d = 0; |
148 | ||
149 | *name = n; | |
150 | return r; | |
151 | } | |
152 | ||
642900d3 TG |
153 | /* @label_terminal: terminal character of a label, updated to point to the terminal character of |
154 | * the previous label (always skipping one dot) or to NULL if there are no more | |
155 | * labels. */ | |
156 | int dns_label_unescape_suffix(const char *name, const char **label_terminal, char *dest, size_t sz) { | |
157 | const char *terminal; | |
158 | int r; | |
159 | ||
160 | assert(name); | |
161 | assert(label_terminal); | |
162 | assert(dest); | |
163 | ||
164 | /* no more labels */ | |
165 | if (!*label_terminal) { | |
166 | if (sz >= 1) | |
167 | *dest = 0; | |
168 | ||
169 | return 0; | |
170 | } | |
171 | ||
56512859 | 172 | terminal = *label_terminal; |
4c701096 | 173 | assert(IN_SET(*terminal, 0, '.')); |
642900d3 | 174 | |
56512859 LP |
175 | /* Skip current terminal character (and accept domain names ending it ".") */ |
176 | if (*terminal == 0) | |
177 | terminal--; | |
178 | if (terminal >= name && *terminal == '.') | |
179 | terminal--; | |
642900d3 | 180 | |
56512859 | 181 | /* Point name to the last label, and terminal to the preceding terminal symbol (or make it a NULL pointer) */ |
642900d3 TG |
182 | for (;;) { |
183 | if (terminal < name) { | |
56512859 | 184 | /* Reached the first label, so indicate that there are no more */ |
642900d3 TG |
185 | terminal = NULL; |
186 | break; | |
187 | } | |
188 | ||
56512859 | 189 | /* Find the start of the last label */ |
642900d3 TG |
190 | if (*terminal == '.') { |
191 | const char *y; | |
192 | unsigned slashes = 0; | |
193 | ||
194 | for (y = terminal - 1; y >= name && *y == '\\'; y--) | |
313cefa1 | 195 | slashes++; |
642900d3 TG |
196 | |
197 | if (slashes % 2 == 0) { | |
56512859 | 198 | /* The '.' was not escaped */ |
642900d3 TG |
199 | name = terminal + 1; |
200 | break; | |
201 | } else { | |
202 | terminal = y; | |
203 | continue; | |
204 | } | |
205 | } | |
206 | ||
313cefa1 | 207 | terminal--; |
642900d3 TG |
208 | } |
209 | ||
7470cc4c | 210 | r = dns_label_unescape(&name, dest, sz, 0); |
642900d3 TG |
211 | if (r < 0) |
212 | return r; | |
213 | ||
214 | *label_terminal = terminal; | |
215 | ||
216 | return r; | |
217 | } | |
218 | ||
422baca0 | 219 | int dns_label_escape(const char *p, size_t l, char *dest, size_t sz) { |
74b2466e | 220 | char *q; |
74b2466e | 221 | |
3b37fa73 LP |
222 | /* DNS labels must be between 1 and 63 characters long. A |
223 | * zero-length label does not exist. See RFC 2182, Section | |
224 | * 11. */ | |
225 | ||
226 | if (l <= 0 || l > DNS_LABEL_MAX) | |
1fa65c59 | 227 | return -EINVAL; |
422baca0 | 228 | if (sz < 1) |
37ade128 | 229 | return -ENOBUFS; |
1fa65c59 | 230 | |
422baca0 LP |
231 | assert(p); |
232 | assert(dest); | |
74b2466e | 233 | |
422baca0 | 234 | q = dest; |
74b2466e LP |
235 | while (l > 0) { |
236 | ||
4c701096 | 237 | if (IN_SET(*p, '.', '\\')) { |
74b2466e | 238 | |
3b37fa73 LP |
239 | /* Dot or backslash */ |
240 | ||
422baca0 | 241 | if (sz < 3) |
37ade128 | 242 | return -ENOBUFS; |
422baca0 | 243 | |
74b2466e LP |
244 | *(q++) = '\\'; |
245 | *(q++) = *p; | |
246 | ||
422baca0 LP |
247 | sz -= 2; |
248 | ||
4c701096 | 249 | } else if (IN_SET(*p, '_', '-') || |
74b2466e LP |
250 | (*p >= '0' && *p <= '9') || |
251 | (*p >= 'a' && *p <= 'z') || | |
252 | (*p >= 'A' && *p <= 'Z')) { | |
253 | ||
254 | /* Proper character */ | |
422baca0 LP |
255 | |
256 | if (sz < 2) | |
37ade128 | 257 | return -ENOBUFS; |
422baca0 | 258 | |
74b2466e | 259 | *(q++) = *p; |
422baca0 LP |
260 | sz -= 1; |
261 | ||
c7feab76 | 262 | } else { |
74b2466e LP |
263 | |
264 | /* Everything else */ | |
422baca0 LP |
265 | |
266 | if (sz < 5) | |
37ade128 | 267 | return -ENOBUFS; |
422baca0 | 268 | |
74b2466e | 269 | *(q++) = '\\'; |
07bed172 LP |
270 | *(q++) = '0' + (char) ((uint8_t) *p / 100); |
271 | *(q++) = '0' + (char) (((uint8_t) *p / 10) % 10); | |
272 | *(q++) = '0' + (char) ((uint8_t) *p % 10); | |
74b2466e | 273 | |
422baca0 | 274 | sz -= 4; |
c7feab76 | 275 | } |
74b2466e LP |
276 | |
277 | p++; | |
278 | l--; | |
279 | } | |
280 | ||
281 | *q = 0; | |
422baca0 LP |
282 | return (int) (q - dest); |
283 | } | |
284 | ||
285 | int dns_label_escape_new(const char *p, size_t l, char **ret) { | |
286 | _cleanup_free_ char *s = NULL; | |
287 | int r; | |
288 | ||
289 | assert(p); | |
290 | assert(ret); | |
291 | ||
3b37fa73 | 292 | if (l <= 0 || l > DNS_LABEL_MAX) |
422baca0 LP |
293 | return -EINVAL; |
294 | ||
295 | s = new(char, DNS_LABEL_ESCAPED_MAX); | |
296 | if (!s) | |
297 | return -ENOMEM; | |
298 | ||
299 | r = dns_label_escape(p, l, s, DNS_LABEL_ESCAPED_MAX); | |
300 | if (r < 0) | |
301 | return r; | |
302 | ||
ae2a15bc | 303 | *ret = TAKE_PTR(s); |
74b2466e LP |
304 | |
305 | return r; | |
306 | } | |
307 | ||
349cc4a5 | 308 | #if HAVE_LIBIDN |
87057e24 | 309 | int dns_label_apply_idna(const char *encoded, size_t encoded_size, char *decoded, size_t decoded_max) { |
bdf10b5b | 310 | _cleanup_free_ uint32_t *input = NULL; |
3b37fa73 | 311 | size_t input_size, l; |
bdf10b5b LP |
312 | const char *p; |
313 | bool contains_8bit = false; | |
3b37fa73 | 314 | char buffer[DNS_LABEL_MAX+1]; |
bdf10b5b LP |
315 | |
316 | assert(encoded); | |
317 | assert(decoded); | |
3b37fa73 LP |
318 | |
319 | /* Converts an U-label into an A-label */ | |
bdf10b5b LP |
320 | |
321 | if (encoded_size <= 0) | |
3b37fa73 | 322 | return -EINVAL; |
bdf10b5b LP |
323 | |
324 | for (p = encoded; p < encoded + encoded_size; p++) | |
325 | if ((uint8_t) *p > 127) | |
326 | contains_8bit = true; | |
327 | ||
3b37fa73 LP |
328 | if (!contains_8bit) { |
329 | if (encoded_size > DNS_LABEL_MAX) | |
330 | return -EINVAL; | |
331 | ||
bdf10b5b | 332 | return 0; |
3b37fa73 | 333 | } |
bdf10b5b LP |
334 | |
335 | input = stringprep_utf8_to_ucs4(encoded, encoded_size, &input_size); | |
336 | if (!input) | |
337 | return -ENOMEM; | |
338 | ||
3b37fa73 LP |
339 | if (idna_to_ascii_4i(input, input_size, buffer, 0) != 0) |
340 | return -EINVAL; | |
341 | ||
342 | l = strlen(buffer); | |
343 | ||
c629ff58 | 344 | /* Verify that the result is not longer than one DNS label. */ |
3b37fa73 | 345 | if (l <= 0 || l > DNS_LABEL_MAX) |
bdf10b5b | 346 | return -EINVAL; |
3b37fa73 | 347 | if (l > decoded_max) |
37ade128 | 348 | return -ENOBUFS; |
3b37fa73 LP |
349 | |
350 | memcpy(decoded, buffer, l); | |
bdf10b5b | 351 | |
3b37fa73 LP |
352 | /* If there's room, append a trailing NUL byte, but only then */ |
353 | if (decoded_max > l) | |
354 | decoded[l] = 0; | |
355 | ||
356 | return (int) l; | |
bdf10b5b LP |
357 | } |
358 | ||
359 | int dns_label_undo_idna(const char *encoded, size_t encoded_size, char *decoded, size_t decoded_max) { | |
bdf10b5b LP |
360 | size_t input_size, output_size; |
361 | _cleanup_free_ uint32_t *input = NULL; | |
362 | _cleanup_free_ char *result = NULL; | |
363 | uint32_t *output = NULL; | |
364 | size_t w; | |
365 | ||
3b37fa73 | 366 | /* To be invoked after unescaping. Converts an A-label into an U-label. */ |
bdf10b5b LP |
367 | |
368 | assert(encoded); | |
369 | assert(decoded); | |
370 | ||
3b37fa73 LP |
371 | if (encoded_size <= 0 || encoded_size > DNS_LABEL_MAX) |
372 | return -EINVAL; | |
373 | ||
d27b725a | 374 | if (!memory_startswith(encoded, encoded_size, IDNA_ACE_PREFIX)) |
bdf10b5b LP |
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 | 400 | return w; |
bdf10b5b | 401 | } |
87057e24 | 402 | #endif |
bdf10b5b | 403 | |
7470cc4c | 404 | int dns_name_concat(const char *a, const char *b, DNSLabelFlags flags, char **_ret) { |
74b2466e LP |
405 | _cleanup_free_ char *ret = NULL; |
406 | size_t n = 0, allocated = 0; | |
3a519900 | 407 | const char *p; |
74b2466e LP |
408 | bool first = true; |
409 | int r; | |
410 | ||
3a519900 LP |
411 | if (a) |
412 | p = a; | |
1cc6c93a YW |
413 | else if (b) |
414 | p = TAKE_PTR(b); | |
415 | else | |
3a519900 | 416 | goto finish; |
74b2466e LP |
417 | |
418 | for (;;) { | |
74b2466e LP |
419 | char label[DNS_LABEL_MAX]; |
420 | ||
7470cc4c | 421 | r = dns_label_unescape(&p, label, sizeof label, flags); |
74b2466e LP |
422 | if (r < 0) |
423 | return r; | |
424 | if (r == 0) { | |
425 | if (*p != 0) | |
426 | return -EINVAL; | |
9ca45586 LP |
427 | |
428 | if (b) { | |
429 | /* Now continue with the second string, if there is one */ | |
1cc6c93a | 430 | p = TAKE_PTR(b); |
9ca45586 LP |
431 | continue; |
432 | } | |
433 | ||
74b2466e LP |
434 | break; |
435 | } | |
436 | ||
9ca45586 | 437 | if (_ret) { |
422baca0 | 438 | if (!GREEDY_REALLOC(ret, allocated, n + !first + DNS_LABEL_ESCAPED_MAX)) |
9ca45586 | 439 | return -ENOMEM; |
74b2466e | 440 | |
422baca0 LP |
441 | r = dns_label_escape(label, r, ret + n + !first, DNS_LABEL_ESCAPED_MAX); |
442 | if (r < 0) | |
443 | return r; | |
444 | ||
9ca45586 | 445 | if (!first) |
422baca0 LP |
446 | ret[n] = '.'; |
447 | } else { | |
448 | char escaped[DNS_LABEL_ESCAPED_MAX]; | |
9ca45586 | 449 | |
422baca0 LP |
450 | r = dns_label_escape(label, r, escaped, sizeof(escaped)); |
451 | if (r < 0) | |
452 | return r; | |
9ca45586 | 453 | } |
74b2466e | 454 | |
422baca0 LP |
455 | if (!first) |
456 | n++; | |
457 | else | |
458 | first = false; | |
459 | ||
74b2466e LP |
460 | n += r; |
461 | } | |
462 | ||
3a519900 | 463 | finish: |
1dfbf000 LP |
464 | if (n > DNS_HOSTNAME_MAX) |
465 | return -EINVAL; | |
466 | ||
7b9f7afc | 467 | if (_ret) { |
3a519900 LP |
468 | if (n == 0) { |
469 | /* Nothing appended? If so, generate at least a single dot, to indicate the DNS root domain */ | |
470 | if (!GREEDY_REALLOC(ret, allocated, 2)) | |
471 | return -ENOMEM; | |
472 | ||
473 | ret[n++] = '.'; | |
474 | } else { | |
475 | if (!GREEDY_REALLOC(ret, allocated, n + 1)) | |
476 | return -ENOMEM; | |
477 | } | |
9ca45586 LP |
478 | |
479 | ret[n] = 0; | |
1cc6c93a | 480 | *_ret = TAKE_PTR(ret); |
7b9f7afc | 481 | } |
74b2466e LP |
482 | |
483 | return 0; | |
484 | } | |
485 | ||
7a08d314 | 486 | void dns_name_hash_func(const char *p, struct siphash *state) { |
74b2466e LP |
487 | int r; |
488 | ||
489 | assert(p); | |
490 | ||
d12315a4 | 491 | for (;;) { |
74b2466e LP |
492 | char label[DNS_LABEL_MAX+1]; |
493 | ||
7470cc4c | 494 | r = dns_label_unescape(&p, label, sizeof label, 0); |
74b2466e LP |
495 | if (r < 0) |
496 | break; | |
d12315a4 LP |
497 | if (r == 0) |
498 | break; | |
74b2466e | 499 | |
509eddd2 LP |
500 | ascii_strlower_n(label, r); |
501 | siphash24_compress(label, r, state); | |
d5115566 | 502 | siphash24_compress_byte(0, state); /* make sure foobar and foo.bar result in different hashes */ |
74b2466e | 503 | } |
1e2527a6 TG |
504 | |
505 | /* enforce that all names are terminated by the empty label */ | |
506 | string_hash_func("", state); | |
74b2466e LP |
507 | } |
508 | ||
7a08d314 | 509 | int dns_name_compare_func(const char *a, const char *b) { |
5dfd7011 | 510 | const char *x, *y; |
23b298bc | 511 | int r, q; |
74b2466e LP |
512 | |
513 | assert(a); | |
514 | assert(b); | |
515 | ||
7a08d314 YW |
516 | x = a + strlen(a); |
517 | y = b + strlen(b); | |
5dfd7011 | 518 | |
74b2466e | 519 | for (;;) { |
34361485 | 520 | char la[DNS_LABEL_MAX], lb[DNS_LABEL_MAX]; |
74b2466e | 521 | |
5dfd7011 | 522 | if (x == NULL && y == NULL) |
74b2466e LP |
523 | return 0; |
524 | ||
5dfd7011 TG |
525 | r = dns_label_unescape_suffix(a, &x, la, sizeof(la)); |
526 | q = dns_label_unescape_suffix(b, &y, lb, sizeof(lb)); | |
74b2466e | 527 | if (r < 0 || q < 0) |
b994fe95 | 528 | return CMP(r, q); |
74b2466e | 529 | |
34361485 | 530 | r = ascii_strcasecmp_nn(la, r, lb, q); |
74b2466e LP |
531 | if (r != 0) |
532 | return r; | |
533 | } | |
534 | } | |
535 | ||
7a08d314 | 536 | DEFINE_HASH_OPS(dns_name_hash_ops, char, dns_name_hash_func, dns_name_compare_func); |
d5099efc | 537 | |
74b2466e | 538 | int dns_name_equal(const char *x, const char *y) { |
81ec9e08 | 539 | int r, q; |
74b2466e LP |
540 | |
541 | assert(x); | |
542 | assert(y); | |
543 | ||
544 | for (;;) { | |
3095011d | 545 | char la[DNS_LABEL_MAX], lb[DNS_LABEL_MAX]; |
74b2466e | 546 | |
7470cc4c | 547 | r = dns_label_unescape(&x, la, sizeof la, 0); |
74b2466e LP |
548 | if (r < 0) |
549 | return r; | |
bdf10b5b | 550 | |
7470cc4c | 551 | q = dns_label_unescape(&y, lb, sizeof lb, 0); |
74b2466e LP |
552 | if (q < 0) |
553 | return q; | |
3b37fa73 | 554 | |
3095011d LP |
555 | if (r != q) |
556 | return false; | |
557 | if (r == 0) | |
558 | return true; | |
74b2466e | 559 | |
3095011d | 560 | if (ascii_strcasecmp_n(la, lb, r) != 0) |
74b2466e LP |
561 | return false; |
562 | } | |
563 | } | |
564 | ||
565 | int dns_name_endswith(const char *name, const char *suffix) { | |
566 | const char *n, *s, *saved_n = NULL; | |
81ec9e08 | 567 | int r, q; |
74b2466e LP |
568 | |
569 | assert(name); | |
570 | assert(suffix); | |
571 | ||
572 | n = name; | |
573 | s = suffix; | |
574 | ||
575 | for (;;) { | |
3095011d | 576 | char ln[DNS_LABEL_MAX], ls[DNS_LABEL_MAX]; |
74b2466e | 577 | |
7470cc4c | 578 | r = dns_label_unescape(&n, ln, sizeof ln, 0); |
74b2466e LP |
579 | if (r < 0) |
580 | return r; | |
581 | ||
582 | if (!saved_n) | |
583 | saved_n = n; | |
584 | ||
7470cc4c | 585 | q = dns_label_unescape(&s, ls, sizeof ls, 0); |
be754d54 LP |
586 | if (q < 0) |
587 | return q; | |
74b2466e LP |
588 | |
589 | if (r == 0 && q == 0) | |
590 | return true; | |
591 | if (r == 0 && saved_n == n) | |
592 | return false; | |
593 | ||
3095011d | 594 | if (r != q || ascii_strcasecmp_n(ln, ls, r) != 0) { |
74b2466e LP |
595 | |
596 | /* Not the same, let's jump back, and try with the next label again */ | |
597 | s = suffix; | |
ae2a15bc | 598 | n = TAKE_PTR(saved_n); |
74b2466e LP |
599 | } |
600 | } | |
601 | } | |
602 | ||
eb241cdb LP |
603 | int dns_name_startswith(const char *name, const char *prefix) { |
604 | const char *n, *p; | |
605 | int r, q; | |
606 | ||
607 | assert(name); | |
608 | assert(prefix); | |
609 | ||
610 | n = name; | |
611 | p = prefix; | |
612 | ||
613 | for (;;) { | |
614 | char ln[DNS_LABEL_MAX], lp[DNS_LABEL_MAX]; | |
615 | ||
7470cc4c | 616 | r = dns_label_unescape(&p, lp, sizeof lp, 0); |
eb241cdb LP |
617 | if (r < 0) |
618 | return r; | |
619 | if (r == 0) | |
620 | return true; | |
621 | ||
7470cc4c | 622 | q = dns_label_unescape(&n, ln, sizeof ln, 0); |
eb241cdb LP |
623 | if (q < 0) |
624 | return q; | |
625 | ||
626 | if (r != q) | |
627 | return false; | |
628 | if (ascii_strcasecmp_n(ln, lp, r) != 0) | |
629 | return false; | |
630 | } | |
631 | } | |
632 | ||
58db254a LP |
633 | int dns_name_change_suffix(const char *name, const char *old_suffix, const char *new_suffix, char **ret) { |
634 | const char *n, *s, *saved_before = NULL, *saved_after = NULL, *prefix; | |
81ec9e08 | 635 | int r, q; |
58db254a LP |
636 | |
637 | assert(name); | |
638 | assert(old_suffix); | |
639 | assert(new_suffix); | |
640 | assert(ret); | |
641 | ||
642 | n = name; | |
643 | s = old_suffix; | |
644 | ||
645 | for (;;) { | |
3095011d | 646 | char ln[DNS_LABEL_MAX], ls[DNS_LABEL_MAX]; |
58db254a LP |
647 | |
648 | if (!saved_before) | |
649 | saved_before = n; | |
650 | ||
7470cc4c | 651 | r = dns_label_unescape(&n, ln, sizeof ln, 0); |
58db254a LP |
652 | if (r < 0) |
653 | return r; | |
58db254a LP |
654 | |
655 | if (!saved_after) | |
656 | saved_after = n; | |
657 | ||
7470cc4c | 658 | q = dns_label_unescape(&s, ls, sizeof ls, 0); |
58db254a LP |
659 | if (q < 0) |
660 | return q; | |
58db254a LP |
661 | |
662 | if (r == 0 && q == 0) | |
663 | break; | |
664 | if (r == 0 && saved_after == n) { | |
665 | *ret = NULL; /* doesn't match */ | |
666 | return 0; | |
667 | } | |
668 | ||
3095011d | 669 | if (r != q || ascii_strcasecmp_n(ln, ls, r) != 0) { |
58db254a LP |
670 | |
671 | /* Not the same, let's jump back, and try with the next label again */ | |
672 | s = old_suffix; | |
1cc6c93a YW |
673 | n = TAKE_PTR(saved_after); |
674 | saved_before = NULL; | |
58db254a LP |
675 | } |
676 | } | |
677 | ||
678 | /* Found it! Now generate the new name */ | |
679 | prefix = strndupa(name, saved_before - name); | |
680 | ||
7470cc4c | 681 | r = dns_name_concat(prefix, new_suffix, 0, ret); |
58db254a LP |
682 | if (r < 0) |
683 | return r; | |
684 | ||
685 | return 1; | |
686 | } | |
687 | ||
ae72b22c | 688 | int dns_name_between(const char *a, const char *b, const char *c) { |
ae72b22c TG |
689 | /* Determine if b is strictly greater than a and strictly smaller than c. |
690 | We consider the order of names to be circular, so that if a is | |
691 | strictly greater than c, we consider b to be between them if it is | |
692 | either greater than a or smaller than c. This is how the canonical | |
693 | DNS name order used in NSEC records work. */ | |
694 | ||
59f2725c LP |
695 | if (dns_name_compare_func(a, c) < 0) |
696 | /* | |
697 | a and c are properly ordered: | |
698 | a<---b--->c | |
699 | */ | |
ae72b22c TG |
700 | return dns_name_compare_func(a, b) < 0 && |
701 | dns_name_compare_func(b, c) < 0; | |
702 | else | |
59f2725c LP |
703 | /* |
704 | a and c are equal or 'reversed': | |
705 | <--b--c a-----> | |
706 | or: | |
707 | <-----c a--b--> | |
708 | */ | |
ae72b22c TG |
709 | return dns_name_compare_func(b, c) < 0 || |
710 | dns_name_compare_func(a, b) < 0; | |
711 | } | |
712 | ||
74b2466e LP |
713 | int dns_name_reverse(int family, const union in_addr_union *a, char **ret) { |
714 | const uint8_t *p; | |
715 | int r; | |
716 | ||
717 | assert(a); | |
718 | assert(ret); | |
719 | ||
720 | p = (const uint8_t*) a; | |
721 | ||
722 | if (family == AF_INET) | |
723 | r = asprintf(ret, "%u.%u.%u.%u.in-addr.arpa", p[3], p[2], p[1], p[0]); | |
724 | else if (family == AF_INET6) | |
3fe1169f LP |
725 | 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", |
726 | hexchar(p[15] & 0xF), hexchar(p[15] >> 4), hexchar(p[14] & 0xF), hexchar(p[14] >> 4), | |
727 | hexchar(p[13] & 0xF), hexchar(p[13] >> 4), hexchar(p[12] & 0xF), hexchar(p[12] >> 4), | |
728 | hexchar(p[11] & 0xF), hexchar(p[11] >> 4), hexchar(p[10] & 0xF), hexchar(p[10] >> 4), | |
729 | hexchar(p[ 9] & 0xF), hexchar(p[ 9] >> 4), hexchar(p[ 8] & 0xF), hexchar(p[ 8] >> 4), | |
730 | hexchar(p[ 7] & 0xF), hexchar(p[ 7] >> 4), hexchar(p[ 6] & 0xF), hexchar(p[ 6] >> 4), | |
731 | hexchar(p[ 5] & 0xF), hexchar(p[ 5] >> 4), hexchar(p[ 4] & 0xF), hexchar(p[ 4] >> 4), | |
732 | hexchar(p[ 3] & 0xF), hexchar(p[ 3] >> 4), hexchar(p[ 2] & 0xF), hexchar(p[ 2] >> 4), | |
733 | hexchar(p[ 1] & 0xF), hexchar(p[ 1] >> 4), hexchar(p[ 0] & 0xF), hexchar(p[ 0] >> 4)); | |
74b2466e LP |
734 | else |
735 | return -EAFNOSUPPORT; | |
736 | if (r < 0) | |
737 | return -ENOMEM; | |
738 | ||
739 | return 0; | |
740 | } | |
741 | ||
b914e211 LP |
742 | int dns_name_address(const char *p, int *family, union in_addr_union *address) { |
743 | int r; | |
744 | ||
745 | assert(p); | |
746 | assert(family); | |
747 | assert(address); | |
748 | ||
749 | r = dns_name_endswith(p, "in-addr.arpa"); | |
750 | if (r < 0) | |
751 | return r; | |
752 | if (r > 0) { | |
753 | uint8_t a[4]; | |
754 | unsigned i; | |
755 | ||
756 | for (i = 0; i < ELEMENTSOF(a); i++) { | |
757 | char label[DNS_LABEL_MAX+1]; | |
758 | ||
7470cc4c | 759 | r = dns_label_unescape(&p, label, sizeof label, 0); |
b914e211 LP |
760 | if (r < 0) |
761 | return r; | |
762 | if (r == 0) | |
763 | return -EINVAL; | |
764 | if (r > 3) | |
765 | return -EINVAL; | |
766 | ||
767 | r = safe_atou8(label, &a[i]); | |
768 | if (r < 0) | |
769 | return r; | |
770 | } | |
771 | ||
772 | r = dns_name_equal(p, "in-addr.arpa"); | |
773 | if (r <= 0) | |
774 | return r; | |
775 | ||
776 | *family = AF_INET; | |
777 | address->in.s_addr = htobe32(((uint32_t) a[3] << 24) | | |
778 | ((uint32_t) a[2] << 16) | | |
779 | ((uint32_t) a[1] << 8) | | |
780 | (uint32_t) a[0]); | |
781 | ||
782 | return 1; | |
783 | } | |
784 | ||
785 | r = dns_name_endswith(p, "ip6.arpa"); | |
786 | if (r < 0) | |
787 | return r; | |
788 | if (r > 0) { | |
789 | struct in6_addr a; | |
790 | unsigned i; | |
791 | ||
792 | for (i = 0; i < ELEMENTSOF(a.s6_addr); i++) { | |
793 | char label[DNS_LABEL_MAX+1]; | |
794 | int x, y; | |
795 | ||
7470cc4c | 796 | r = dns_label_unescape(&p, label, sizeof label, 0); |
b914e211 LP |
797 | if (r <= 0) |
798 | return r; | |
799 | if (r != 1) | |
800 | return -EINVAL; | |
801 | x = unhexchar(label[0]); | |
802 | if (x < 0) | |
803 | return -EINVAL; | |
804 | ||
7470cc4c | 805 | r = dns_label_unescape(&p, label, sizeof label, 0); |
b914e211 LP |
806 | if (r <= 0) |
807 | return r; | |
808 | if (r != 1) | |
809 | return -EINVAL; | |
810 | y = unhexchar(label[0]); | |
811 | if (y < 0) | |
812 | return -EINVAL; | |
813 | ||
814 | a.s6_addr[ELEMENTSOF(a.s6_addr) - i - 1] = (uint8_t) y << 4 | (uint8_t) x; | |
815 | } | |
816 | ||
817 | r = dns_name_equal(p, "ip6.arpa"); | |
818 | if (r <= 0) | |
819 | return r; | |
820 | ||
821 | *family = AF_INET6; | |
822 | address->in6 = a; | |
823 | return 1; | |
824 | } | |
825 | ||
826 | return 0; | |
827 | } | |
828 | ||
dc477e73 | 829 | bool dns_name_is_root(const char *name) { |
74b2466e LP |
830 | |
831 | assert(name); | |
832 | ||
dc477e73 LP |
833 | /* There are exactly two ways to encode the root domain name: |
834 | * as empty string, or with a single dot. */ | |
74b2466e | 835 | |
dc477e73 | 836 | return STR_IN_SET(name, "", "."); |
74b2466e LP |
837 | } |
838 | ||
dc477e73 | 839 | bool dns_name_is_single_label(const char *name) { |
74b2466e LP |
840 | int r; |
841 | ||
842 | assert(name); | |
843 | ||
f6fbd9c2 | 844 | r = dns_name_parent(&name); |
dc477e73 LP |
845 | if (r <= 0) |
846 | return false; | |
74b2466e | 847 | |
dc477e73 | 848 | return dns_name_is_root(name); |
74b2466e | 849 | } |
54adabf7 | 850 | |
50dee79b | 851 | /* Encode a domain name according to RFC 1035 Section 3.1, without compression */ |
3cd03457 | 852 | int dns_name_to_wire_format(const char *domain, uint8_t *buffer, size_t len, bool canonical) { |
c6cefd13 | 853 | uint8_t *label_length, *out; |
54adabf7 BG |
854 | int r; |
855 | ||
c6cefd13 LP |
856 | assert(domain); |
857 | assert(buffer); | |
54adabf7 BG |
858 | |
859 | out = buffer; | |
860 | ||
861 | do { | |
50dee79b | 862 | /* Reserve a byte for label length */ |
c6cefd13 | 863 | if (len <= 0) |
54adabf7 BG |
864 | return -ENOBUFS; |
865 | len--; | |
866 | label_length = out; | |
867 | out++; | |
868 | ||
50dee79b LP |
869 | /* Convert and copy a single label. Note that |
870 | * dns_label_unescape() returns 0 when it hits the end | |
871 | * of the domain name, which we rely on here to encode | |
872 | * the trailing NUL byte. */ | |
7470cc4c | 873 | r = dns_label_unescape(&domain, (char *) out, len, 0); |
54adabf7 BG |
874 | if (r < 0) |
875 | return r; | |
876 | ||
b577e3d5 LP |
877 | /* Optionally, output the name in DNSSEC canonical |
878 | * format, as described in RFC 4034, section 6.2. Or | |
879 | * in other words: in lower-case. */ | |
880 | if (canonical) | |
881 | ascii_strlower_n((char*) out, (size_t) r); | |
3cd03457 | 882 | |
50dee79b | 883 | /* Fill label length, move forward */ |
54adabf7 BG |
884 | *label_length = r; |
885 | out += r; | |
886 | len -= r; | |
50dee79b | 887 | |
54adabf7 BG |
888 | } while (r != 0); |
889 | ||
50dee79b LP |
890 | /* Verify the maximum size of the encoded name. The trailing |
891 | * dot + NUL byte account are included this time, hence | |
892 | * compare against DNS_HOSTNAME_MAX + 2 (which is 255) this | |
893 | * time. */ | |
894 | if (out - buffer > DNS_HOSTNAME_MAX + 2) | |
895 | return -EINVAL; | |
896 | ||
54adabf7 BG |
897 | return out - buffer; |
898 | } | |
0a49b6b6 | 899 | |
0e8eedbb LP |
900 | static bool srv_type_label_is_valid(const char *label, size_t n) { |
901 | size_t k; | |
902 | ||
903 | assert(label); | |
904 | ||
905 | if (n < 2) /* Label needs to be at least 2 chars long */ | |
906 | return false; | |
907 | ||
908 | if (label[0] != '_') /* First label char needs to be underscore */ | |
909 | return false; | |
910 | ||
911 | /* Second char must be a letter */ | |
912 | if (!(label[1] >= 'A' && label[1] <= 'Z') && | |
913 | !(label[1] >= 'a' && label[1] <= 'z')) | |
914 | return false; | |
915 | ||
916 | /* Third and further chars must be alphanumeric or a hyphen */ | |
917 | for (k = 2; k < n; k++) { | |
918 | if (!(label[k] >= 'A' && label[k] <= 'Z') && | |
919 | !(label[k] >= 'a' && label[k] <= 'z') && | |
920 | !(label[k] >= '0' && label[k] <= '9') && | |
921 | label[k] != '-') | |
922 | return false; | |
923 | } | |
924 | ||
925 | return true; | |
926 | } | |
927 | ||
7e8131e9 | 928 | bool dns_srv_type_is_valid(const char *name) { |
0a49b6b6 LP |
929 | unsigned c = 0; |
930 | int r; | |
931 | ||
932 | if (!name) | |
7e8131e9 | 933 | return false; |
0a49b6b6 LP |
934 | |
935 | for (;;) { | |
936 | char label[DNS_LABEL_MAX]; | |
0a49b6b6 LP |
937 | |
938 | /* This more or less implements RFC 6335, Section 5.1 */ | |
939 | ||
7470cc4c | 940 | r = dns_label_unescape(&name, label, sizeof label, 0); |
0a49b6b6 | 941 | if (r < 0) |
7e8131e9 | 942 | return false; |
0a49b6b6 | 943 | if (r == 0) |
0e8eedbb | 944 | break; |
0a49b6b6 | 945 | |
0e8eedbb | 946 | if (c >= 2) |
7e8131e9 | 947 | return false; |
0a49b6b6 | 948 | |
0e8eedbb | 949 | if (!srv_type_label_is_valid(label, r)) |
7e8131e9 | 950 | return false; |
0a49b6b6 LP |
951 | |
952 | c++; | |
953 | } | |
0e8eedbb LP |
954 | |
955 | return c == 2; /* exactly two labels */ | |
0a49b6b6 LP |
956 | } |
957 | ||
154ae087 DR |
958 | bool dnssd_srv_type_is_valid(const char *name) { |
959 | return dns_srv_type_is_valid(name) && | |
960 | ((dns_name_endswith(name, "_tcp") > 0) || | |
961 | (dns_name_endswith(name, "_udp") > 0)); /* Specific to DNS-SD. RFC 6763, Section 7 */ | |
962 | } | |
963 | ||
0a49b6b6 LP |
964 | bool dns_service_name_is_valid(const char *name) { |
965 | size_t l; | |
966 | ||
967 | /* This more or less implements RFC 6763, Section 4.1.1 */ | |
968 | ||
969 | if (!name) | |
970 | return false; | |
971 | ||
972 | if (!utf8_is_valid(name)) | |
973 | return false; | |
974 | ||
975 | if (string_has_cc(name, NULL)) | |
976 | return false; | |
977 | ||
978 | l = strlen(name); | |
979 | if (l <= 0) | |
980 | return false; | |
981 | if (l > 63) | |
982 | return false; | |
983 | ||
984 | return true; | |
985 | } | |
0e8eedbb LP |
986 | |
987 | int dns_service_join(const char *name, const char *type, const char *domain, char **ret) { | |
422baca0 LP |
988 | char escaped[DNS_LABEL_ESCAPED_MAX]; |
989 | _cleanup_free_ char *n = NULL; | |
0e8eedbb LP |
990 | int r; |
991 | ||
992 | assert(type); | |
993 | assert(domain); | |
994 | assert(ret); | |
995 | ||
7e8131e9 | 996 | if (!dns_srv_type_is_valid(type)) |
0e8eedbb LP |
997 | return -EINVAL; |
998 | ||
999 | if (!name) | |
7470cc4c | 1000 | return dns_name_concat(type, domain, 0, ret); |
0e8eedbb LP |
1001 | |
1002 | if (!dns_service_name_is_valid(name)) | |
1003 | return -EINVAL; | |
1004 | ||
422baca0 | 1005 | r = dns_label_escape(name, strlen(name), escaped, sizeof(escaped)); |
0e8eedbb LP |
1006 | if (r < 0) |
1007 | return r; | |
1008 | ||
7470cc4c | 1009 | r = dns_name_concat(type, domain, 0, &n); |
0e8eedbb LP |
1010 | if (r < 0) |
1011 | return r; | |
1012 | ||
7470cc4c | 1013 | return dns_name_concat(escaped, n, 0, ret); |
0e8eedbb LP |
1014 | } |
1015 | ||
1016 | static bool dns_service_name_label_is_valid(const char *label, size_t n) { | |
1017 | char *s; | |
1018 | ||
1019 | assert(label); | |
1020 | ||
1021 | if (memchr(label, 0, n)) | |
1022 | return false; | |
1023 | ||
1024 | s = strndupa(label, n); | |
1025 | return dns_service_name_is_valid(s); | |
1026 | } | |
1027 | ||
1028 | int dns_service_split(const char *joined, char **_name, char **_type, char **_domain) { | |
1029 | _cleanup_free_ char *name = NULL, *type = NULL, *domain = NULL; | |
1030 | const char *p = joined, *q = NULL, *d = NULL; | |
1031 | char a[DNS_LABEL_MAX], b[DNS_LABEL_MAX], c[DNS_LABEL_MAX]; | |
1032 | int an, bn, cn, r; | |
1033 | unsigned x = 0; | |
1034 | ||
1035 | assert(joined); | |
1036 | ||
1037 | /* Get first label from the full name */ | |
7470cc4c | 1038 | an = dns_label_unescape(&p, a, sizeof(a), 0); |
0e8eedbb LP |
1039 | if (an < 0) |
1040 | return an; | |
1041 | ||
1042 | if (an > 0) { | |
1043 | x++; | |
1044 | ||
1045 | /* If there was a first label, try to get the second one */ | |
7470cc4c | 1046 | bn = dns_label_unescape(&p, b, sizeof(b), 0); |
0e8eedbb LP |
1047 | if (bn < 0) |
1048 | return bn; | |
1049 | ||
1050 | if (bn > 0) { | |
1051 | x++; | |
1052 | ||
1053 | /* If there was a second label, try to get the third one */ | |
1054 | q = p; | |
7470cc4c | 1055 | cn = dns_label_unescape(&p, c, sizeof(c), 0); |
0e8eedbb LP |
1056 | if (cn < 0) |
1057 | return cn; | |
1058 | ||
1059 | if (cn > 0) | |
1060 | x++; | |
1061 | } else | |
1062 | cn = 0; | |
1063 | } else | |
1064 | an = 0; | |
1065 | ||
1066 | if (x >= 2 && srv_type_label_is_valid(b, bn)) { | |
1067 | ||
1068 | if (x >= 3 && srv_type_label_is_valid(c, cn)) { | |
1069 | ||
1070 | if (dns_service_name_label_is_valid(a, an)) { | |
0e8eedbb LP |
1071 | /* OK, got <name> . <type> . <type2> . <domain> */ |
1072 | ||
1073 | name = strndup(a, an); | |
1074 | if (!name) | |
1075 | return -ENOMEM; | |
1076 | ||
605405c6 | 1077 | type = strjoin(b, ".", c); |
0e8eedbb LP |
1078 | if (!type) |
1079 | return -ENOMEM; | |
0e8eedbb LP |
1080 | |
1081 | d = p; | |
1082 | goto finish; | |
1083 | } | |
1084 | ||
1085 | } else if (srv_type_label_is_valid(a, an)) { | |
1086 | ||
1087 | /* OK, got <type> . <type2> . <domain> */ | |
1088 | ||
1089 | name = NULL; | |
1090 | ||
605405c6 | 1091 | type = strjoin(a, ".", b); |
0e8eedbb LP |
1092 | if (!type) |
1093 | return -ENOMEM; | |
0e8eedbb LP |
1094 | |
1095 | d = q; | |
1096 | goto finish; | |
1097 | } | |
1098 | } | |
1099 | ||
1100 | name = NULL; | |
1101 | type = NULL; | |
1102 | d = joined; | |
1103 | ||
1104 | finish: | |
7470cc4c | 1105 | r = dns_name_normalize(d, 0, &domain); |
0e8eedbb LP |
1106 | if (r < 0) |
1107 | return r; | |
1108 | ||
1cc6c93a YW |
1109 | if (_domain) |
1110 | *_domain = TAKE_PTR(domain); | |
0e8eedbb | 1111 | |
1cc6c93a YW |
1112 | if (_type) |
1113 | *_type = TAKE_PTR(type); | |
0e8eedbb | 1114 | |
1cc6c93a YW |
1115 | if (_name) |
1116 | *_name = TAKE_PTR(name); | |
0e8eedbb LP |
1117 | |
1118 | return 0; | |
1119 | } | |
e7ff0e0b | 1120 | |
f2a3de01 | 1121 | static int dns_name_build_suffix_table(const char *name, const char *table[]) { |
e7ff0e0b | 1122 | const char *p; |
b9282bc1 | 1123 | unsigned n = 0; |
e7ff0e0b LP |
1124 | int r; |
1125 | ||
1126 | assert(name); | |
b9282bc1 | 1127 | assert(table); |
e7ff0e0b LP |
1128 | |
1129 | p = name; | |
1130 | for (;;) { | |
1131 | if (n > DNS_N_LABELS_MAX) | |
1132 | return -EINVAL; | |
1133 | ||
b9282bc1 | 1134 | table[n] = p; |
e7ff0e0b LP |
1135 | r = dns_name_parent(&p); |
1136 | if (r < 0) | |
1137 | return r; | |
1138 | if (r == 0) | |
1139 | break; | |
1140 | ||
1141 | n++; | |
1142 | } | |
1143 | ||
b9282bc1 LP |
1144 | return (int) n; |
1145 | } | |
1146 | ||
1147 | int dns_name_suffix(const char *name, unsigned n_labels, const char **ret) { | |
1148 | const char* labels[DNS_N_LABELS_MAX+1]; | |
1149 | int n; | |
1150 | ||
1151 | assert(name); | |
1152 | assert(ret); | |
1153 | ||
1154 | n = dns_name_build_suffix_table(name, labels); | |
1155 | if (n < 0) | |
1156 | return n; | |
1157 | ||
1158 | if ((unsigned) n < n_labels) | |
e7ff0e0b LP |
1159 | return -EINVAL; |
1160 | ||
1161 | *ret = labels[n - n_labels]; | |
1162 | return (int) (n - n_labels); | |
1163 | } | |
1164 | ||
97c67192 LP |
1165 | int dns_name_skip(const char *a, unsigned n_labels, const char **ret) { |
1166 | int r; | |
1167 | ||
1168 | assert(a); | |
1169 | assert(ret); | |
1170 | ||
313cefa1 | 1171 | for (; n_labels > 0; n_labels--) { |
97c67192 LP |
1172 | r = dns_name_parent(&a); |
1173 | if (r < 0) | |
1174 | return r; | |
1175 | if (r == 0) { | |
1176 | *ret = ""; | |
1177 | return 0; | |
1178 | } | |
1179 | } | |
1180 | ||
1181 | *ret = a; | |
1182 | return 1; | |
1183 | } | |
1184 | ||
e7ff0e0b LP |
1185 | int dns_name_count_labels(const char *name) { |
1186 | unsigned n = 0; | |
1187 | const char *p; | |
1188 | int r; | |
1189 | ||
1190 | assert(name); | |
1191 | ||
1192 | p = name; | |
1193 | for (;;) { | |
1194 | r = dns_name_parent(&p); | |
1195 | if (r < 0) | |
1196 | return r; | |
1197 | if (r == 0) | |
1198 | break; | |
1199 | ||
1200 | if (n >= DNS_N_LABELS_MAX) | |
1201 | return -EINVAL; | |
1202 | ||
1203 | n++; | |
1204 | } | |
1205 | ||
1206 | return (int) n; | |
1207 | } | |
db5b0e92 LP |
1208 | |
1209 | int dns_name_equal_skip(const char *a, unsigned n_labels, const char *b) { | |
1210 | int r; | |
1211 | ||
1212 | assert(a); | |
1213 | assert(b); | |
1214 | ||
97c67192 LP |
1215 | r = dns_name_skip(a, n_labels, &a); |
1216 | if (r <= 0) | |
1217 | return r; | |
db5b0e92 LP |
1218 | |
1219 | return dns_name_equal(a, b); | |
1220 | } | |
b9282bc1 LP |
1221 | |
1222 | int dns_name_common_suffix(const char *a, const char *b, const char **ret) { | |
1223 | const char *a_labels[DNS_N_LABELS_MAX+1], *b_labels[DNS_N_LABELS_MAX+1]; | |
1224 | int n = 0, m = 0, k = 0, r, q; | |
1225 | ||
1226 | assert(a); | |
1227 | assert(b); | |
1228 | assert(ret); | |
1229 | ||
1230 | /* Determines the common suffix of domain names a and b */ | |
1231 | ||
1232 | n = dns_name_build_suffix_table(a, a_labels); | |
1233 | if (n < 0) | |
1234 | return n; | |
1235 | ||
1236 | m = dns_name_build_suffix_table(b, b_labels); | |
1237 | if (m < 0) | |
1238 | return m; | |
1239 | ||
1240 | for (;;) { | |
1241 | char la[DNS_LABEL_MAX], lb[DNS_LABEL_MAX]; | |
1242 | const char *x, *y; | |
1243 | ||
1244 | if (k >= n || k >= m) { | |
1245 | *ret = a_labels[n - k]; | |
1246 | return 0; | |
1247 | } | |
1248 | ||
1249 | x = a_labels[n - 1 - k]; | |
7470cc4c | 1250 | r = dns_label_unescape(&x, la, sizeof la, 0); |
b9282bc1 LP |
1251 | if (r < 0) |
1252 | return r; | |
1253 | ||
1254 | y = b_labels[m - 1 - k]; | |
7470cc4c | 1255 | q = dns_label_unescape(&y, lb, sizeof lb, 0); |
b9282bc1 LP |
1256 | if (q < 0) |
1257 | return q; | |
1258 | ||
1259 | if (r != q || ascii_strcasecmp_n(la, lb, r) != 0) { | |
1260 | *ret = a_labels[n - k]; | |
1261 | return 0; | |
1262 | } | |
1263 | ||
1264 | k++; | |
1265 | } | |
1266 | } | |
0cf40f55 LP |
1267 | |
1268 | int dns_name_apply_idna(const char *name, char **ret) { | |
87057e24 ZJS |
1269 | /* Return negative on error, 0 if not implemented, positive on success. */ |
1270 | ||
349cc4a5 | 1271 | #if HAVE_LIBIDN2 |
87057e24 | 1272 | int r; |
0926f348 | 1273 | _cleanup_free_ char *t = NULL; |
87057e24 ZJS |
1274 | |
1275 | assert(name); | |
1276 | assert(ret); | |
1277 | ||
0926f348 | 1278 | r = idn2_lookup_u8((uint8_t*) name, (uint8_t**) &t, |
87057e24 | 1279 | IDN2_NFC_INPUT | IDN2_NONTRANSITIONAL); |
0926f348 ZJS |
1280 | log_debug("idn2_lookup_u8: %s → %s", name, t); |
1281 | if (r == IDN2_OK) { | |
1282 | if (!startswith(name, "xn--")) { | |
1283 | _cleanup_free_ char *s = NULL; | |
1284 | ||
1285 | r = idn2_to_unicode_8z8z(t, &s, 0); | |
1286 | if (r != IDN2_OK) { | |
1287 | log_debug("idn2_to_unicode_8z8z(\"%s\") failed: %d/%s", | |
1288 | t, r, idn2_strerror(r)); | |
1289 | return 0; | |
1290 | } | |
1291 | ||
1292 | if (!streq_ptr(name, s)) { | |
1293 | log_debug("idn2 roundtrip failed: \"%s\" → \"%s\" → \"%s\", ignoring.", | |
1294 | name, t, s); | |
1295 | return 0; | |
1296 | } | |
1297 | } | |
1298 | ||
1cc6c93a YW |
1299 | *ret = TAKE_PTR(t); |
1300 | ||
87057e24 | 1301 | return 1; /* *ret has been written */ |
0926f348 ZJS |
1302 | } |
1303 | ||
1304 | log_debug("idn2_lookup_u8(\"%s\") failed: %d/%s", name, r, idn2_strerror(r)); | |
ad1f3fe6 | 1305 | if (r == IDN2_2HYPHEN) |
f21f31b2 | 1306 | /* The name has two hyphens — forbidden by IDNA2008 in some cases */ |
ad1f3fe6 ZJS |
1307 | return 0; |
1308 | if (IN_SET(r, IDN2_TOO_BIG_DOMAIN, IDN2_TOO_BIG_LABEL)) | |
87057e24 | 1309 | return -ENOSPC; |
ad1f3fe6 | 1310 | return -EINVAL; |
349cc4a5 | 1311 | #elif HAVE_LIBIDN |
0cf40f55 LP |
1312 | _cleanup_free_ char *buf = NULL; |
1313 | size_t n = 0, allocated = 0; | |
1314 | bool first = true; | |
1315 | int r, q; | |
1316 | ||
1317 | assert(name); | |
1318 | assert(ret); | |
1319 | ||
1320 | for (;;) { | |
1321 | char label[DNS_LABEL_MAX]; | |
1322 | ||
7470cc4c | 1323 | r = dns_label_unescape(&name, label, sizeof label, 0); |
0cf40f55 LP |
1324 | if (r < 0) |
1325 | return r; | |
1326 | if (r == 0) | |
1327 | break; | |
1328 | ||
7470cc4c | 1329 | q = dns_label_apply_idna(label, r, label, sizeof label); |
0cf40f55 LP |
1330 | if (q < 0) |
1331 | return q; | |
1332 | if (q > 0) | |
1333 | r = q; | |
1334 | ||
1335 | if (!GREEDY_REALLOC(buf, allocated, n + !first + DNS_LABEL_ESCAPED_MAX)) | |
1336 | return -ENOMEM; | |
1337 | ||
1338 | r = dns_label_escape(label, r, buf + n + !first, DNS_LABEL_ESCAPED_MAX); | |
1339 | if (r < 0) | |
1340 | return r; | |
1341 | ||
1342 | if (first) | |
1343 | first = false; | |
1344 | else | |
1345 | buf[n++] = '.'; | |
1346 | ||
ad1f3fe6 | 1347 | n += r; |
0cf40f55 LP |
1348 | } |
1349 | ||
1350 | if (n > DNS_HOSTNAME_MAX) | |
1351 | return -EINVAL; | |
1352 | ||
1353 | if (!GREEDY_REALLOC(buf, allocated, n + 1)) | |
1354 | return -ENOMEM; | |
1355 | ||
1356 | buf[n] = 0; | |
1cc6c93a | 1357 | *ret = TAKE_PTR(buf); |
0cf40f55 | 1358 | |
ad1f3fe6 | 1359 | return 1; |
87057e24 ZJS |
1360 | #else |
1361 | return 0; | |
1362 | #endif | |
0cf40f55 | 1363 | } |
08a4849e LP |
1364 | |
1365 | int dns_name_is_valid_or_address(const char *name) { | |
1366 | /* Returns > 0 if the specified name is either a valid IP address formatted as string or a valid DNS name */ | |
1367 | ||
1368 | if (isempty(name)) | |
1369 | return 0; | |
1370 | ||
1371 | if (in_addr_from_string_auto(name, NULL, NULL) >= 0) | |
1372 | return 1; | |
1373 | ||
1374 | return dns_name_is_valid(name); | |
1375 | } |