1#ifndef foorrhfoo
2#define foorrhfoo
3
4/***
5  This file is part of avahi.
6
7  avahi is free software; you can redistribute it and/or modify it
8  under the terms of the GNU Lesser General Public License as
9  published by the Free Software Foundation; either version 2.1 of the
10  License, or (at your option) any later version.
11
12  avahi is distributed in the hope that it will be useful, but WITHOUT
13  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
14  or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
15  Public License for more details.
16
17  You should have received a copy of the GNU Lesser General Public
18  License along with avahi; if not, write to the Free Software
19  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
20  USA.
21***/
22
23/** \file rr.h Functions and definitions for manipulating DNS resource record (RR) data. */
24
25#include <inttypes.h>
26#include <sys/types.h>
27
28#include <avahi-common/strlst.h>
29#include <avahi-common/address.h>
30#include <avahi-common/cdecl.h>
31
32AVAHI_C_DECL_BEGIN
33
34/** DNS record types, see RFC 1035, in addition to those defined in defs.h */
35enum {
36    AVAHI_DNS_TYPE_ANY = 0xFF,   /**< Special query type for requesting all records */
37    AVAHI_DNS_TYPE_OPT = 41,     /**< EDNS0 option */
38    AVAHI_DNS_TYPE_TKEY = 249,
39    AVAHI_DNS_TYPE_TSIG = 250,
40    AVAHI_DNS_TYPE_IXFR = 251,
41    AVAHI_DNS_TYPE_AXFR = 252
42};
43
44/** DNS record classes, see RFC 1035, in addition to those defined in defs.h */
45enum {
46    AVAHI_DNS_CLASS_ANY = 0xFF,         /**< Special query type for requesting all records */
47    AVAHI_DNS_CACHE_FLUSH = 0x8000,     /**< Not really a class but a bit which may be set in response packets, see mDNS spec for more information */
48    AVAHI_DNS_UNICAST_RESPONSE = 0x8000 /**< Not really a class but a bit which may be set in query packets, see mDNS spec for more information */
49};
50
51/** Encapsulates a DNS query key consisting of class, type and
52    name. Use avahi_key_ref()/avahi_key_unref() for manipulating the
53    reference counter. The structure is intended to be treated as "immutable", no
54    changes should be imposed after creation */
55typedef struct AvahiKey {
56    int ref;           /**< Reference counter */
57    char *name;        /**< Record name */
58    uint16_t clazz;    /**< Record class, one of the AVAHI_DNS_CLASS_xxx constants */
59    uint16_t type;     /**< Record type, one of the AVAHI_DNS_TYPE_xxx constants */
60} AvahiKey;
61
62/** Encapsulates a DNS resource record. The structure is intended to
63 * be treated as "immutable", no changes should be imposed after
64 * creation. */
65typedef struct AvahiRecord {
66    int ref;         /**< Reference counter */
67    AvahiKey *key;   /**< Reference to the query key of this record */
68
69    uint32_t ttl;     /**< DNS TTL of this record */
70
71    union {
72
73        struct {
74            void* data;
75            uint16_t size;
76        } generic; /**< Generic record data for unknown types */
77
78        struct {
79            uint16_t priority;
80            uint16_t weight;
81            uint16_t port;
82            char *name;
83        } srv; /**< Data for SRV records */
84
85        struct {
86            char *name;
87        } ptr, ns, cname; /**< Data for PTR, NS and CNAME records */
88
89        struct {
90            char *cpu;
91            char *os;
92        } hinfo; /**< Data for HINFO records */
93
94        struct {
95            AvahiStringList *string_list;
96        } txt; /**< Data for TXT records */
97
98        struct {
99            AvahiIPv4Address address;
100        } a; /**< Data for A records */
101
102        struct {
103            AvahiIPv6Address address;
104        } aaaa; /**< Data for AAAA records */
105
106    } data; /**< Record data */
107
108} AvahiRecord;
109
110/** Create a new AvahiKey object. The reference counter will be set to 1. */
111AvahiKey *avahi_key_new(const char *name, uint16_t clazz, uint16_t type);
112
113/** Increase the reference counter of an AvahiKey object by one */
114AvahiKey *avahi_key_ref(AvahiKey *k);
115
116/** Decrease the reference counter of an AvahiKey object by one */
117void avahi_key_unref(AvahiKey *k);
118
119/** Check whether two AvahiKey object contain the same
120 * data. AVAHI_DNS_CLASS_ANY/AVAHI_DNS_TYPE_ANY are treated like any
121 * other class/type. */
122int avahi_key_equal(const AvahiKey *a, const AvahiKey *b);
123
124/** Return a numeric hash value for a key for usage in hash tables. */
125unsigned avahi_key_hash(const AvahiKey *k);
126
127/** Create a new record object. Record data should be filled in right after creation. The reference counter is set to 1. */
128AvahiRecord *avahi_record_new(AvahiKey *k, uint32_t ttl);
129
130/** Create a new record object. Record data should be filled in right after creation. The reference counter is set to 1. */
131AvahiRecord *avahi_record_new_full(const char *name, uint16_t clazz, uint16_t type, uint32_t ttl);
132
133/** Increase the reference counter of an AvahiRecord by one. */
134AvahiRecord *avahi_record_ref(AvahiRecord *r);
135
136/** Decrease the reference counter of an AvahiRecord by one. */
137void avahi_record_unref(AvahiRecord *r);
138
139/** Return a textual representation of the specified DNS class. The
140 * returned pointer points to a read only internal string. */
141const char *avahi_dns_class_to_string(uint16_t clazz);
142
143/** Return a textual representation of the specified DNS class. The
144 * returned pointer points to a read only internal string. */
145const char *avahi_dns_type_to_string(uint16_t type);
146
147/** Create a textual representation of the specified key. avahi_free() the
148 * result! */
149char *avahi_key_to_string(const AvahiKey *k);
150
151/** Create a textual representation of the specified record, similar
152 * in style to BIND zone file data. avahi_free() the result! */
153char *avahi_record_to_string(const AvahiRecord *r);
154
155/** Check whether two records are equal (regardless of the TTL */
156int avahi_record_equal_no_ttl(const AvahiRecord *a, const AvahiRecord *b);
157
158/** Check whether the specified key is valid */
159int avahi_key_is_valid(AvahiKey *k);
160
161/** Check whether the specified record is valid */
162int avahi_record_is_valid(AvahiRecord *r);
163
164/** Parse a binary rdata object and fill it into *record. This function is actually implemented in dns.c */
165int avahi_rdata_parse(AvahiRecord *record, const void* rdata, size_t size);
166
167/** Serialize an AvahiRecord object into binary rdata. This function is actually implemented in dns.c */
168size_t avahi_rdata_serialize(AvahiRecord *record, void *rdata, size_t max_size);
169
170/** Return TRUE if the AvahiRecord object is a link-local A or AAAA address */
171int avahi_record_is_link_local_address(const AvahiRecord *r);
172
173AVAHI_C_DECL_END
174
175#endif
176