src/shared/dns-domain.h

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 #pragma once
   3
   4 /***
   5   This file is part of systemd.
   6
   7   Copyright 2014 Lennart Poettering
   8
   9   systemd is free software; you can redistribute it and/or modify it
  10   under the terms of the GNU Lesser General Public License as published by
  11   the Free Software Foundation; either version 2.1 of the License, or
  12   (at your option) any later version.
  13
  14   systemd is distributed in the hope that it will be useful, but
  15   WITHOUT ANY WARRANTY; without even the implied warranty of
  16   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  17   Lesser General Public License for more details.
  18
  19   You should have received a copy of the GNU Lesser General Public License
  20   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  21  ***/
  22
  23 #include <errno.h>
  24 #include <stdbool.h>
  25 #include <stddef.h>
  26 #include <stdint.h>
  27
  28 #include "hashmap.h"
  29 #include "in-addr-util.h"
  30
  31 /* Length of a single label, with all escaping removed, excluding any trailing dot or NUL byte */
  32 #define DNS_LABEL_MAX 63
  33
  34 /* Worst case length of a single label, with all escaping applied and room for a trailing NUL byte. */
  35 #define DNS_LABEL_ESCAPED_MAX (DNS_LABEL_MAX*4+1)
  36
  37 /* Maximum length of a full hostname, consisting of a series of unescaped labels, and no trailing dot or NUL byte */
  38 #define DNS_HOSTNAME_MAX 253
  39
  40 /* Maximum length of a full hostname, on the wire, including the final NUL byte */
  41 #define DNS_WIRE_FOMAT_HOSTNAME_MAX 255
  42
  43 /* Maximum number of labels per valid hostname */
  44 #define DNS_N_LABELS_MAX 127
  45
  46 int dns_label_unescape(const char **name, char *dest, size_t sz);
  47 int dns_label_unescape_suffix(const char *name, const char **label_end, char *dest, size_t sz);
  48 int dns_label_escape(const char *p, size_t l, char *dest, size_t sz);
  49 int dns_label_escape_new(const char *p, size_t l, char **ret);
  50
  51 static inline int dns_name_parent(const char **name) {
  52         return dns_label_unescape(name, NULL, DNS_LABEL_MAX);
  53 }
  54
  55 #if HAVE_LIBIDN
  56 int dns_label_apply_idna(const char *encoded, size_t encoded_size, char *decoded, size_t decoded_max);
  57 int dns_label_undo_idna(const char *encoded, size_t encoded_size, char *decoded, size_t decoded_max);
  58 #endif
  59
  60 int dns_name_concat(const char *a, const char *b, char **ret);
  61
  62 static inline int dns_name_normalize(const char *s, char **ret) {
  63         /* dns_name_concat() normalizes as a side-effect */
  64         return dns_name_concat(s, NULL, ret);
  65 }
  66
  67 static inline int dns_name_is_valid(const char *s) {
  68         int r;
  69
  70         /* dns_name_normalize() verifies as a side effect */
  71         r = dns_name_normalize(s, NULL);
  72         if (r == -EINVAL)
  73                 return 0;
  74         if (r < 0)
  75                 return r;
  76         return 1;
  77 }
  78
  79 void dns_name_hash_func(const void *s, struct siphash *state);
  80 int dns_name_compare_func(const void *a, const void *b);
  81 extern const struct hash_ops dns_name_hash_ops;
  82
  83 int dns_name_between(const char *a, const char *b, const char *c);
  84 int dns_name_equal(const char *x, const char *y);
  85 int dns_name_endswith(const char *name, const char *suffix);
  86 int dns_name_startswith(const char *name, const char *prefix);
  87
  88 int dns_name_change_suffix(const char *name, const char *old_suffix, const char *new_suffix, char **ret);
  89
  90 int dns_name_reverse(int family, const union in_addr_union *a, char **ret);
  91 int dns_name_address(const char *p, int *family, union in_addr_union *a);
  92
  93 bool dns_name_is_root(const char *name);
  94 bool dns_name_is_single_label(const char *name);
  95
  96 int dns_name_to_wire_format(const char *domain, uint8_t *buffer, size_t len, bool canonical);
  97
  98 bool dns_srv_type_is_valid(const char *name);
  99 bool dns_service_name_is_valid(const char *name);
 100
 101 int dns_service_join(const char *name, const char *type, const char *domain, char **ret);
 102 int dns_service_split(const char *joined, char **name, char **type, char **domain);
 103
 104 int dns_name_suffix(const char *name, unsigned n_labels, const char **ret);
 105 int dns_name_count_labels(const char *name);
 106
 107 int dns_name_skip(const char *a, unsigned n_labels, const char **ret);
 108 int dns_name_equal_skip(const char *a, unsigned n_labels, const char *b);
 109
 110 int dns_name_common_suffix(const char *a, const char *b, const char **ret);
 111
 112 int dns_name_apply_idna(const char *name, char **ret);
 113
 114 int dns_name_is_valid_or_address(const char *name);