src/shared/dns-domain.h

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2 #pragma once
   3
   4 #include <errno.h>
   5 #include <stdbool.h>
   6 #include <stddef.h>
   7 #include <stdint.h>
   8
   9 #include "dns-def.h"
  10 #include "hashmap.h"
  11 #include "in-addr-util.h"
  12
  13 typedef enum DNSLabelFlags {
  14         DNS_LABEL_LDH                = 1 << 0, /* Follow the "LDH" rule — only letters, digits, and internal hyphens. */
  15         DNS_LABEL_NO_ESCAPES         = 1 << 1, /* Do not treat backslashes specially */
  16         DNS_LABEL_LEAVE_TRAILING_DOT = 1 << 2, /* Leave trailing dot in place */
  17 } DNSLabelFlags;
  18
  19 int dns_label_unescape(const char **name, char *dest, size_t sz, DNSLabelFlags flags);
  20 int dns_label_unescape_suffix(const char *name, const char **label_end, char *dest, size_t sz);
  21 int dns_label_escape(const char *p, size_t l, char *dest, size_t sz);
  22 int dns_label_escape_new(const char *p, size_t l, char **ret);
  23
  24 static inline int dns_name_parent(const char **name) {
  25         return dns_label_unescape(name, NULL, DNS_LABEL_MAX, 0);
  26 }
  27
  28 #if HAVE_LIBIDN
  29 int dns_label_apply_idna(const char *encoded, size_t encoded_size, char *decoded, size_t decoded_max);
  30 int dns_label_undo_idna(const char *encoded, size_t encoded_size, char *decoded, size_t decoded_max);
  31 #endif
  32
  33 int dns_name_concat(const char *a, const char *b, DNSLabelFlags flags, char **ret);
  34
  35 static inline int dns_name_normalize(const char *s, DNSLabelFlags flags, char **ret) {
  36         /* dns_name_concat() normalizes as a side-effect */
  37         return dns_name_concat(s, NULL, flags, ret);
  38 }
  39
  40 static inline int dns_name_is_valid(const char *s) {
  41         int r;
  42
  43         /* dns_name_normalize() verifies as a side effect */
  44         r = dns_name_normalize(s, 0, NULL);
  45         if (r == -EINVAL)
  46                 return 0;
  47         if (r < 0)
  48                 return r;
  49         return 1;
  50 }
  51
  52 static inline int dns_name_is_valid_ldh(const char *s) {
  53         int r;
  54
  55         r = dns_name_concat(s, NULL, DNS_LABEL_LDH|DNS_LABEL_NO_ESCAPES, NULL);
  56         if (r == -EINVAL)
  57                 return 0;
  58         if (r < 0)
  59                 return r;
  60         return 1;
  61 }
  62
  63 static inline bool dns_name_is_empty(const char *s) {
  64         return isempty(s) || streq(s, ".");
  65 }
  66
  67 void dns_name_hash_func(const char *s, struct siphash *state);
  68 int dns_name_compare_func(const char *a, const char *b);
  69 extern const struct hash_ops dns_name_hash_ops;
  70
  71 int dns_name_between(const char *a, const char *b, const char *c);
  72 int dns_name_equal(const char *x, const char *y);
  73 int dns_name_endswith(const char *name, const char *suffix);
  74 int dns_name_startswith(const char *name, const char *prefix);
  75
  76 int dns_name_change_suffix(const char *name, const char *old_suffix, const char *new_suffix, char **ret);
  77
  78 int dns_name_reverse(int family, const union in_addr_union *a, char **ret);
  79 int dns_name_address(const char *p, int *family, union in_addr_union *a);
  80
  81 bool dns_name_is_root(const char *name);
  82 bool dns_name_is_single_label(const char *name);
  83
  84 int dns_name_to_wire_format(const char *domain, uint8_t *buffer, size_t len, bool canonical);
  85
  86 bool dns_srv_type_is_valid(const char *name);
  87 bool dnssd_srv_type_is_valid(const char *name);
  88 bool dns_service_name_is_valid(const char *name);
  89
  90 int dns_service_join(const char *name, const char *type, const char *domain, char **ret);
  91 int dns_service_split(const char *joined, char **name, char **type, char **domain);
  92
  93 int dns_name_suffix(const char *name, unsigned n_labels, const char **ret);
  94 int dns_name_count_labels(const char *name);
  95
  96 int dns_name_skip(const char *a, unsigned n_labels, const char **ret);
  97 int dns_name_equal_skip(const char *a, unsigned n_labels, const char *b);
  98
  99 int dns_name_common_suffix(const char *a, const char *b, const char **ret);
 100
 101 int dns_name_apply_idna(const char *name, char **ret);
 102
 103 int dns_name_is_valid_or_address(const char *name);
 104
 105 int dns_name_dot_suffixed(const char *name);