1 /* SPDX-License-Identifier: LGPL-2.1+ */
5 This file is part of systemd.
7 Copyright 2014 Lennart Poettering
16 #include "in-addr-util.h"
18 /* Length of a single label, with all escaping removed, excluding any trailing dot or NUL byte */
19 #define DNS_LABEL_MAX 63
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)
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
27 /* Maximum length of a full hostname, on the wire, including the final NUL byte */
28 #define DNS_WIRE_FOMAT_HOSTNAME_MAX 255
30 /* Maximum number of labels per valid hostname */
31 #define DNS_N_LABELS_MAX 127
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
);
38 static inline int dns_name_parent(const char **name
) {
39 return dns_label_unescape(name
, NULL
, DNS_LABEL_MAX
);
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
);
47 int dns_name_concat(const char *a
, const char *b
, char **ret
);
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
);
54 static inline int dns_name_is_valid(const char *s
) {
57 /* dns_name_normalize() verifies as a side effect */
58 r
= dns_name_normalize(s
, NULL
);
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
;
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
);
75 int dns_name_change_suffix(const char *name
, const char *old_suffix
, const char *new_suffix
, char **ret
);
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
);
80 bool dns_name_is_root(const char *name
);
81 bool dns_name_is_single_label(const char *name
);
83 int dns_name_to_wire_format(const char *domain
, uint8_t *buffer
, size_t len
, bool canonical
);
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
);
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
);
92 int dns_name_suffix(const char *name
, unsigned n_labels
, const char **ret
);
93 int dns_name_count_labels(const char *name
);
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
);
98 int dns_name_common_suffix(const char *a
, const char *b
, const char **ret
);
100 int dns_name_apply_idna(const char *name
, char **ret
);
102 int dns_name_is_valid_or_address(const char *name
);