Line data    Source code

       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             : typedef enum DNSLabelFlags {
      28             :         DNS_LABEL_LDH        = 1 << 0, /* Follow the "LDH" rule — only letters, digits, and internal hyphens. */
      29             :         DNS_LABEL_NO_ESCAPES = 1 << 1, /* Do not treat backslashes specially */
      30             : } DNSLabelFlags;
      31             : 
      32             : int dns_label_unescape(const char **name, char *dest, size_t sz, DNSLabelFlags flags);
      33             : int dns_label_unescape_suffix(const char *name, const char **label_end, char *dest, size_t sz);
      34             : int dns_label_escape(const char *p, size_t l, char *dest, size_t sz);
      35             : int dns_label_escape_new(const char *p, size_t l, char **ret);
      36             : 
      37         163 : static inline int dns_name_parent(const char **name) {
      38         163 :         return dns_label_unescape(name, NULL, DNS_LABEL_MAX, 0);
      39             : }
      40             : 
      41             : #if HAVE_LIBIDN
      42             : int dns_label_apply_idna(const char *encoded, size_t encoded_size, char *decoded, size_t decoded_max);
      43             : int dns_label_undo_idna(const char *encoded, size_t encoded_size, char *decoded, size_t decoded_max);
      44             : #endif
      45             : 
      46             : int dns_name_concat(const char *a, const char *b, DNSLabelFlags flags, char **ret);
      47             : 
      48          87 : static inline int dns_name_normalize(const char *s, DNSLabelFlags flags, char **ret) {
      49             :         /* dns_name_concat() normalizes as a side-effect */
      50          87 :         return dns_name_concat(s, NULL, flags, ret);
      51             : }
      52             : 
      53          59 : static inline int dns_name_is_valid(const char *s) {
      54             :         int r;
      55             : 
      56             :         /* dns_name_normalize() verifies as a side effect */
      57          59 :         r = dns_name_normalize(s, 0, NULL);
      58          59 :         if (r == -EINVAL)
      59          17 :                 return 0;
      60          42 :         if (r < 0)
      61           0 :                 return r;
      62          42 :         return 1;
      63             : }
      64             : 
      65          72 : static inline int dns_name_is_valid_ldh(const char *s) {
      66             :         int r;
      67             : 
      68          72 :         r = dns_name_concat(s, NULL, DNS_LABEL_LDH|DNS_LABEL_NO_ESCAPES, NULL);
      69          72 :         if (r == -EINVAL)
      70          24 :                 return 0;
      71          48 :         if (r < 0)
      72           0 :                 return r;
      73          48 :         return 1;
      74             : }
      75             : 
      76             : void dns_name_hash_func(const char *s, struct siphash *state);
      77             : int dns_name_compare_func(const char *a, const char *b);
      78             : extern const struct hash_ops dns_name_hash_ops;
      79             : 
      80             : int dns_name_between(const char *a, const char *b, const char *c);
      81             : int dns_name_equal(const char *x, const char *y);
      82             : int dns_name_endswith(const char *name, const char *suffix);
      83             : int dns_name_startswith(const char *name, const char *prefix);
      84             : 
      85             : int dns_name_change_suffix(const char *name, const char *old_suffix, const char *new_suffix, char **ret);
      86             : 
      87             : int dns_name_reverse(int family, const union in_addr_union *a, char **ret);
      88             : int dns_name_address(const char *p, int *family, union in_addr_union *a);
      89             : 
      90             : bool dns_name_is_root(const char *name);
      91             : bool dns_name_is_single_label(const char *name);
      92             : 
      93             : int dns_name_to_wire_format(const char *domain, uint8_t *buffer, size_t len, bool canonical);
      94             : 
      95             : bool dns_srv_type_is_valid(const char *name);
      96             : bool dnssd_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);
     111             : 
     112             : int dns_name_is_valid_or_address(const char *name);