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
  10 #include <errno.h>
  11 #include <stdbool.h>
  12 #include <stddef.h>
  13 #include <stdint.h>
  14
  15 #include "hashmap.h"
  16 #include "in-addr-util.h"
  17
  18 /* Length of a single label, with all escaping removed, excluding any trailing dot or NUL byte */
  19 #define DNS_LABEL_MAX 63
  20
  21 /* Worst case length of a single label, with all escaping applied and room for a trailing NUL byte. */
  22 #define DNS_LABEL_ESCAPED_MAX (DNS_LABEL_MAX*4+1)
  23
  24 /* Maximum length of a full hostname, consisting of a series of unescaped labels, and no trailing dot or NUL byte */
  25 #define DNS_HOSTNAME_MAX 253
  26
  27 /* Maximum length of a full hostname, on the wire, including the final NUL byte */
  28 #define DNS_WIRE_FORMAT_HOSTNAME_MAX 255
  29
  30 /* Maximum number of labels per valid hostname */
  31 #define DNS_N_LABELS_MAX 127
  32
  33 int dns_label_unescape(const char **name, char *dest, size_t sz);
  34 int dns_label_unescape_suffix(const char *name, const char **label_end, char *dest, size_t sz);
  35 int dns_label_escape(const char *p, size_t l, char *dest, size_t sz);
  36 int dns_label_escape_new(const char *p, size_t l, char **ret);
  37
  38 static inline int dns_name_parent(const char **name) {
  39         return dns_label_unescape(name, NULL, DNS_LABEL_MAX);
  40 }
  41
  42 #if HAVE_LIBIDN
  43 int dns_label_apply_idna(const char *encoded, size_t encoded_size, char *decoded, size_t decoded_max);
  44 int dns_label_undo_idna(const char *encoded, size_t encoded_size, char *decoded, size_t decoded_max);
  45 #endif
  46
  47 int dns_name_concat(const char *a, const char *b, char **ret);
  48
  49 static inline int dns_name_normalize(const char *s, char **ret) {
  50         /* dns_name_concat() normalizes as a side-effect */
  51         return dns_name_concat(s, NULL, ret);
  52 }
  53
  54 static inline int dns_name_is_valid(const char *s) {
  55         int r;
  56
  57         /* dns_name_normalize() verifies as a side effect */
  58         r = dns_name_normalize(s, NULL);
  59         if (r == -EINVAL)
  60                 return 0;
  61         if (r < 0)
  62                 return r;
  63         return 1;
  64 }
  65
  66 void dns_name_hash_func(const void *s, struct siphash *state);
  67 int dns_name_compare_func(const void *a, const void *b);
  68 extern const struct hash_ops dns_name_hash_ops;
  69
  70 int dns_name_between(const char *a, const char *b, const char *c);
  71 int dns_name_equal(const char *x, const char *y);
  72 int dns_name_endswith(const char *name, const char *suffix);
  73 int dns_name_startswith(const char *name, const char *prefix);
  74
  75 int dns_name_change_suffix(const char *name, const char *old_suffix, const char *new_suffix, char **ret);
  76
  77 int dns_name_reverse(int family, const union in_addr_union *a, char **ret);
  78 int dns_name_address(const char *p, int *family, union in_addr_union *a);
  79
  80 bool dns_name_is_root(const char *name);
  81 bool dns_name_is_single_label(const char *name);
  82
  83 int dns_name_to_wire_format(const char *domain, uint8_t *buffer, size_t len, bool canonical);
  84
  85 bool dns_srv_type_is_valid(const char *name);
  86 bool dnssd_srv_type_is_valid(const char *name);
  87 bool dns_service_name_is_valid(const char *name);
  88
  89 int dns_service_join(const char *name, const char *type, const char *domain, char **ret);
  90 int dns_service_split(const char *joined, char **name, char **type, char **domain);
  91
  92 int dns_name_suffix(const char *name, unsigned n_labels, const char **ret);
  93 int dns_name_count_labels(const char *name);
  94
  95 int dns_name_skip(const char *a, unsigned n_labels, const char **ret);
  96 int dns_name_equal_skip(const char *a, unsigned n_labels, const char *b);
  97
  98 int dns_name_common_suffix(const char *a, const char *b, const char **ret);
  99
 100 int dns_name_apply_idna(const char *name, char **ret);
 101
 102 int dns_name_is_valid_or_address(const char *name);