1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
4 This file is part of systemd.
6 Copyright 2014 Lennart Poettering
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.
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.
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/>.
24 #include <stringprep.h>
27 #include "resolved-dns-domain.h"
29 int dns_label_unescape(const char **name, char *dest, size_t sz) {
53 if (r >= DNS_LABEL_MAX)
57 /* Escaped character */
65 else if (*n == '\\' || *n == '.') {
66 /* Escaped backslash or dot */
71 } else if (n[0] >= '0' && n[0] <= '9') {
74 /* Escaped literal ASCII character */
76 if (!(n[1] >= '0' && n[1] <= '9') ||
77 !(n[2] >= '0' && n[2] <= '9'))
80 k = ((unsigned) (n[0] - '0') * 100) +
81 ((unsigned) (n[1] - '0') * 10) +
82 ((unsigned) (n[2] - '0'));
84 /* Don't allow CC characters or anything that doesn't fit in 8bit */
85 if (k < ' ' || k > 255 || k == 127)
96 } else if ((uint8_t) *n >= (uint8_t) ' ' && *n != 127) {
98 /* Normal character */
106 /* Empty label that is not at the end? */
117 int dns_label_escape(const char *p, size_t l, char **ret) {
118 _cleanup_free_ char *s = NULL;
125 if (l > DNS_LABEL_MAX)
128 s = malloc(l * 4 + 1);
135 if (*p == '.' || *p == '\\') {
137 /* Dot or backslash */
141 } else if (*p == '_' ||
143 (*p >= '0' && *p <= '9') ||
144 (*p >= 'a' && *p <= 'z') ||
145 (*p >= 'A' && *p <= 'Z')) {
147 /* Proper character */
149 } else if ((uint8_t) *p >= (uint8_t) ' ' && *p != 127) {
151 /* Everything else */
153 *(q++) = '0' + (char) ((uint8_t) *p / 100);
154 *(q++) = '0' + (char) (((uint8_t) *p / 10) % 10);
155 *(q++) = '0' + (char) ((uint8_t) *p % 10);
172 int dns_label_apply_idna(const char *encoded, size_t encoded_size, char *decoded, size_t decoded_max) {
174 _cleanup_free_ uint32_t *input = NULL;
177 bool contains_8bit = false;
181 assert(decoded_max >= DNS_LABEL_MAX);
183 if (encoded_size <= 0)
186 for (p = encoded; p < encoded + encoded_size; p++)
187 if ((uint8_t) *p > 127)
188 contains_8bit = true;
193 input = stringprep_utf8_to_ucs4(encoded, encoded_size, &input_size);
197 if (idna_to_ascii_4i(input, input_size, decoded, 0) != 0)
200 return strlen(decoded);
206 int dns_label_undo_idna(const char *encoded, size_t encoded_size, char *decoded, size_t decoded_max) {
208 size_t input_size, output_size;
209 _cleanup_free_ uint32_t *input = NULL;
210 _cleanup_free_ char *result = NULL;
211 uint32_t *output = NULL;
214 /* To be invoked after unescaping */
219 if (encoded_size < sizeof(IDNA_ACE_PREFIX)-1)
222 if (memcmp(encoded, IDNA_ACE_PREFIX, sizeof(IDNA_ACE_PREFIX) -1) != 0)
225 input = stringprep_utf8_to_ucs4(encoded, encoded_size, &input_size);
229 output_size = input_size;
230 output = newa(uint32_t, output_size);
232 idna_to_unicode_44i(input, input_size, output, &output_size, 0);
234 result = stringprep_ucs4_to_utf8(output, output_size, NULL, &w);
239 if (w+1 > decoded_max)
242 memcpy(decoded, result, w+1);
249 int dns_name_normalize(const char *s, char **_ret) {
250 _cleanup_free_ char *ret = NULL;
251 size_t n = 0, allocated = 0;
259 _cleanup_free_ char *t = NULL;
260 char label[DNS_LABEL_MAX];
263 r = dns_label_unescape(&p, label, sizeof(label));
272 k = dns_label_undo_idna(label, r, label, sizeof(label));
278 r = dns_label_escape(label, r, &t);
282 if (!GREEDY_REALLOC(ret, allocated, n + !first + strlen(t) + 1))
290 memcpy(ret + n, t, r);
294 if (n > DNS_NAME_MAX)
297 if (!GREEDY_REALLOC(ret, allocated, n + 1))
310 unsigned long dns_name_hash_func(const void *s, const uint8_t hash_key[HASH_KEY_SIZE]) {
312 unsigned long ul = hash_key[0];
318 char label[DNS_LABEL_MAX+1];
321 r = dns_label_unescape(&p, label, sizeof(label));
325 k = dns_label_undo_idna(label, r, label, sizeof(label));
332 ascii_strlower(label);
334 ul = ul * hash_key[1] + ul + string_hash_func(label, hash_key);
340 int dns_name_compare_func(const void *a, const void *b) {
341 const char *x = a, *y = b;
348 char la[DNS_LABEL_MAX+1], lb[DNS_LABEL_MAX+1];
350 if (*x == 0 && *y == 0)
353 r = dns_label_unescape(&x, la, sizeof(la));
354 q = dns_label_unescape(&y, lb, sizeof(lb));
358 k = dns_label_undo_idna(la, r, la, sizeof(la));
359 w = dns_label_undo_idna(lb, q, lb, sizeof(lb));
368 r = strcasecmp(la, lb);
374 int dns_name_equal(const char *x, const char *y) {
381 char la[DNS_LABEL_MAX+1], lb[DNS_LABEL_MAX+1];
383 if (*x == 0 && *y == 0)
386 r = dns_label_unescape(&x, la, sizeof(la));
390 k = dns_label_undo_idna(la, r, la, sizeof(la));
396 q = dns_label_unescape(&y, lb, sizeof(lb));
399 w = dns_label_undo_idna(lb, q, lb, sizeof(lb));
406 if (strcasecmp(la, lb))
411 int dns_name_endswith(const char *name, const char *suffix) {
412 const char *n, *s, *saved_n = NULL;
422 char ln[DNS_LABEL_MAX+1], ls[DNS_LABEL_MAX+1];
424 r = dns_label_unescape(&n, ln, sizeof(ln));
427 k = dns_label_undo_idna(ln, r, ln, sizeof(ln));
436 q = dns_label_unescape(&s, ls, sizeof(ls));
439 w = dns_label_undo_idna(ls, q, ls, sizeof(ls));
445 if (r == 0 && q == 0)
447 if (r == 0 && saved_n == n)
452 if (r != q || strcasecmp(ln, ls)) {
454 /* Not the same, let's jump back, and try with the next label again */
462 int dns_name_reverse(int family, const union in_addr_union *a, char **ret) {
469 p = (const uint8_t*) a;
471 if (family == AF_INET)
472 r = asprintf(ret, "%u.%u.%u.%u.in-addr.arpa", p[3], p[2], p[1], p[0]);
473 else if (family == AF_INET6)
474 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",
475 hexchar(p[15] & 0xF), hexchar(p[15] >> 4), hexchar(p[14] & 0xF), hexchar(p[14] >> 4),
476 hexchar(p[13] & 0xF), hexchar(p[13] >> 4), hexchar(p[12] & 0xF), hexchar(p[12] >> 4),
477 hexchar(p[11] & 0xF), hexchar(p[11] >> 4), hexchar(p[10] & 0xF), hexchar(p[10] >> 4),
478 hexchar(p[ 9] & 0xF), hexchar(p[ 9] >> 4), hexchar(p[ 8] & 0xF), hexchar(p[ 8] >> 4),
479 hexchar(p[ 7] & 0xF), hexchar(p[ 7] >> 4), hexchar(p[ 6] & 0xF), hexchar(p[ 6] >> 4),
480 hexchar(p[ 5] & 0xF), hexchar(p[ 5] >> 4), hexchar(p[ 4] & 0xF), hexchar(p[ 4] >> 4),
481 hexchar(p[ 3] & 0xF), hexchar(p[ 3] >> 4), hexchar(p[ 2] & 0xF), hexchar(p[ 2] >> 4),
482 hexchar(p[ 1] & 0xF), hexchar(p[ 1] >> 4), hexchar(p[ 0] & 0xF), hexchar(p[ 0] >> 4));
484 return -EAFNOSUPPORT;
491 int dns_name_address(const char *p, int *family, union in_addr_union *address) {
498 r = dns_name_endswith(p, "in-addr.arpa");
505 for (i = 0; i < ELEMENTSOF(a); i++) {
506 char label[DNS_LABEL_MAX+1];
508 r = dns_label_unescape(&p, label, sizeof(label));
516 r = safe_atou8(label, &a[i]);
521 r = dns_name_equal(p, "in-addr.arpa");
526 address->in.s_addr = htobe32(((uint32_t) a[3] << 24) |
527 ((uint32_t) a[2] << 16) |
528 ((uint32_t) a[1] << 8) |
534 r = dns_name_endswith(p, "ip6.arpa");
541 for (i = 0; i < ELEMENTSOF(a.s6_addr); i++) {
542 char label[DNS_LABEL_MAX+1];
545 r = dns_label_unescape(&p, label, sizeof(label));
550 x = unhexchar(label[0]);
554 r = dns_label_unescape(&p, label, sizeof(label));
559 y = unhexchar(label[0]);
563 a.s6_addr[ELEMENTSOF(a.s6_addr) - i - 1] = (uint8_t) y << 4 | (uint8_t) x;
566 r = dns_name_equal(p, "ip6.arpa");
578 int dns_name_root(const char *name) {
579 char label[DNS_LABEL_MAX+1];
584 r = dns_label_unescape(&name, label, sizeof(label));
588 return r == 0 && *name == 0;
591 int dns_name_single_label(const char *name) {
592 char label[DNS_LABEL_MAX+1];
597 r = dns_label_unescape(&name, label, sizeof(label));
603 r = dns_label_unescape(&name, label, sizeof(label));
607 return r == 0 && *name == 0;