src/shared/dns-domain.h

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 #pragma once
   3
   4 /***
   5  ***/
   6
   7 #include <errno.h>
   8 #include <stdbool.h>
   9 #include <stddef.h>
  10 #include <stdint.h>
  11
  12 #include "hashmap.h"
  13 #include "in-addr-util.h"
  14
  15 /* Length of a single label, with all escaping removed, excluding any trailing dot or NUL byte */
  16 #define DNS_LABEL_MAX 63
  17
  18 /* Worst case length of a single label, with all escaping applied and room for a trailing NUL byte. */
  19 #define DNS_LABEL_ESCAPED_MAX (DNS_LABEL_MAX*4+1)
  20
  21 /* Maximum length of a full hostname, consisting of a series of unescaped labels, and no trailing dot or NUL byte */
  22 #define DNS_HOSTNAME_MAX 253
  23
  24 /* Maximum length of a full hostname, on the wire, including the final NUL byte */
  25 #define DNS_WIRE_FORMAT_HOSTNAME_MAX 255
  26
  27 /* Maximum number of labels per valid hostname */
  28 #define DNS_N_LABELS_MAX 127
  29
  30 int dns_label_unescape(const char **name, char *dest, size_t sz);
  31 int dns_label_unescape_suffix(const char *name, const char **label_end, char *dest, size_t sz);
  32 int dns_label_escape(const char *p, size_t l, char *dest, size_t sz);
  33 int dns_label_escape_new(const char *p, size_t l, char **ret);
  34
  35 static inline int dns_name_parent(const char **name) {
  36         return dns_label_unescape(name, NULL, DNS_LABEL_MAX);
  37 }
  38
  39 #if HAVE_LIBIDN
  40 int dns_label_apply_idna(const char *encoded, size_t encoded_size, char *decoded, size_t decoded_max);
  41 int dns_label_undo_idna(const char *encoded, size_t encoded_size, char *decoded, size_t decoded_max);
  42 #endif
  43
  44 int dns_name_concat(const char *a, const char *b, char **ret);
  45
  46 static inline int dns_name_normalize(const char *s, char **ret) {
  47         /* dns_name_concat() normalizes as a side-effect */
  48         return dns_name_concat(s, NULL, ret);
  49 }
  50
  51 static inline int dns_name_is_valid(const char *s) {
  52         int r;
  53
  54         /* dns_name_normalize() verifies as a side effect */
  55         r = dns_name_normalize(s, NULL);
  56         if (r == -EINVAL)
  57                 return 0;
  58         if (r < 0)
  59                 return r;
  60         return 1;
  61 }
  62
  63 void dns_name_hash_func(const void *s, struct siphash *state);
  64 int dns_name_compare_func(const void *a, const void *b);
  65 extern const struct hash_ops dns_name_hash_ops;
  66
  67 int dns_name_between(const char *a, const char *b, const char *c);
  68 int dns_name_equal(const char *x, const char *y);
  69 int dns_name_endswith(const char *name, const char *suffix);
  70 int dns_name_startswith(const char *name, const char *prefix);
  71
  72 int dns_name_change_suffix(const char *name, const char *old_suffix, const char *new_suffix, char **ret);
  73
  74 int dns_name_reverse(int family, const union in_addr_union *a, char **ret);
  75 int dns_name_address(const char *p, int *family, union in_addr_union *a);
  76
  77 bool dns_name_is_root(const char *name);
  78 bool dns_name_is_single_label(const char *name);
  79
  80 int dns_name_to_wire_format(const char *domain, uint8_t *buffer, size_t len, bool canonical);
  81
  82 bool dns_srv_type_is_valid(const char *name);
  83 bool dnssd_srv_type_is_valid(const char *name);
  84 bool dns_service_name_is_valid(const char *name);
  85
  86 int dns_service_join(const char *name, const char *type, const char *domain, char **ret);
  87 int dns_service_split(const char *joined, char **name, char **type, char **domain);
  88
  89 int dns_name_suffix(const char *name, unsigned n_labels, const char **ret);
  90 int dns_name_count_labels(const char *name);
  91
  92 int dns_name_skip(const char *a, unsigned n_labels, const char **ret);
  93 int dns_name_equal_skip(const char *a, unsigned n_labels, const char *b);
  94
  95 int dns_name_common_suffix(const char *a, const char *b, const char **ret);
  96
  97 int dns_name_apply_idna(const char *name, char **ret);
  98
  99 int dns_name_is_valid_or_address(const char *name);