src/shared/dns-domain.h

   1 /***
   2   This file is part of systemd.
   3
   4   Copyright 2014 Lennart Poettering
   5
   6   systemd is free software; you can redistribute it and/or modify it
   7   under the terms of the GNU Lesser General Public License as published by
   8   the Free Software Foundation; either version 2.1 of the License, or
   9   (at your option) any later version.
  10
  11   systemd is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   Lesser General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  18  ***/
  19
  20 #pragma once
  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 int dns_label_apply_idna(const char *encoded, size_t encoded_size, char *decoded, size_t decoded_max);
  56 int dns_label_undo_idna(const char *encoded, size_t encoded_size, char *decoded, size_t decoded_max);
  57
  58 int dns_name_concat(const char *a, const char *b, char **ret);
  59
  60 static inline int dns_name_normalize(const char *s, char **ret) {
  61         /* dns_name_concat() normalizes as a side-effect */
  62         return dns_name_concat(s, NULL, ret);
  63 }
  64
  65 static inline int dns_name_is_valid(const char *s) {
  66         int r;
  67
  68         /* dns_name_normalize() verifies as a side effect */
  69         r = dns_name_normalize(s, NULL);
  70         if (r == -EINVAL)
  71                 return 0;
  72         if (r < 0)
  73                 return r;
  74         return 1;
  75 }
  76
  77 void dns_name_hash_func(const void *s, struct siphash *state);
  78 int dns_name_compare_func(const void *a, const void *b);
  79 extern const struct hash_ops dns_name_hash_ops;
  80
  81 int dns_name_between(const char *a, const char *b, const char *c);
  82 int dns_name_equal(const char *x, const char *y);
  83 int dns_name_endswith(const char *name, const char *suffix);
  84 int dns_name_startswith(const char *name, const char *prefix);
  85
  86 int dns_name_change_suffix(const char *name, const char *old_suffix, const char *new_suffix, char **ret);
  87
  88 int dns_name_reverse(int family, const union in_addr_union *a, char **ret);
  89 int dns_name_address(const char *p, int *family, union in_addr_union *a);
  90
  91 bool dns_name_is_root(const char *name);
  92 bool dns_name_is_single_label(const char *name);
  93
  94 int dns_name_to_wire_format(const char *domain, uint8_t *buffer, size_t len, bool canonical);
  95
  96 bool dns_srv_type_is_valid(const char *name);
  97 bool dns_service_name_is_valid(const char *name);
  98
  99 int dns_service_join(const char *name, const char *type, const char *domain, char **ret);
 100 int dns_service_split(const char *joined, char **name, char **type, char **domain);
 101
 102 int dns_name_suffix(const char *name, unsigned n_labels, const char **ret);
 103 int dns_name_count_labels(const char *name);
 104
 105 int dns_name_skip(const char *a, unsigned n_labels, const char **ret);
 106 int dns_name_equal_skip(const char *a, unsigned n_labels, const char *b);
 107
 108 int dns_name_common_suffix(const char *a, const char *b, const char **ret);
 109
 110 int dns_name_apply_idna(const char *name, char **ret);