src/shared/dns-domain.h

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