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 
dns_name_parent(const char ** name)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 
dns_name_normalize(const char * s,DNSLabelFlags flags,char ** ret)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 
dns_name_is_valid(const char * s)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 
dns_name_is_valid_ldh(const char * s)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 
dns_name_is_empty(const char * s)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);
106 
107 bool dns_name_dont_resolve(const char *name);
108