7 This file is part of avahi.
9 avahi is free software; you can redistribute it and/or modify it
10 under the terms of the GNU Lesser General Public License as
11 published by the Free Software Foundation; either version 2.1 of the
12 License, or (at your option) any later version.
14 avahi is distributed in the hope that it will be useful, but WITHOUT
15 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
16 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
17 Public License for more details.
19 You should have received a copy of the GNU Lesser General Public
20 License along with avahi; if not, write to the Free Software
21 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
27 #include <avahi-common/strlst.h>
28 #include <avahi-common/address.h>
29 #include <avahi-common/cdecl.h>
31 /** \file rr.h Functions and definitions for manipulating DNS resource record (RR) data. */
35 /** DNS record types, see RFC 1035 */
37 AVAHI_DNS_TYPE_A = 0x01,
38 AVAHI_DNS_TYPE_NS = 0x02,
39 AVAHI_DNS_TYPE_CNAME = 0x05,
40 AVAHI_DNS_TYPE_SOA = 0x06,
41 AVAHI_DNS_TYPE_PTR = 0x0C,
42 AVAHI_DNS_TYPE_HINFO = 0x0D,
43 AVAHI_DNS_TYPE_MX = 0x0F,
44 AVAHI_DNS_TYPE_TXT = 0x10,
45 AVAHI_DNS_TYPE_AAAA = 0x1C,
46 AVAHI_DNS_TYPE_SRV = 0x21,
47 AVAHI_DNS_TYPE_ANY = 0xFF /**< Special query type for requesting all records */
50 /** DNS record classes, see RFC 1035 */
52 AVAHI_DNS_CLASS_IN = 0x01, /**< Probably the only class we will ever use */
53 AVAHI_DNS_CLASS_ANY = 0xFF, /**< Special query type for requesting all records */
54 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 */
55 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 */
58 /** The default TTL for RRs which contain a host name of some kind. */
59 #define AVAHI_DEFAULT_TTL_HOST_NAME (120)
61 /** The default TTL for all other records. */
62 #define AVAHI_DEFAULT_TTL (75*60)
64 /** Encapsulates a DNS query key consisting of class, type and
65 name. Use avahi_key_ref()/avahi_key_unref() for manipulating the
66 reference counter. The structure is intended to be treated as "immutable", no
67 changes should be imposed after creation */
69 guint ref; /**< Reference counter */
70 gchar *name; /**< Record name */
71 guint16 clazz; /**< Record class, one of the AVAHI_DNS_CLASS_xxx constants */
72 guint16 type; /**< Record type, one of the AVAHI_DNS_TYPE_xxx constants */
75 /** Encapsulates a DNS resource record. The structure is intended to
76 * be treated as "immutable", no changes should be imposed after
79 guint ref; /**< Reference counter */
80 AvahiKey *key; /**< Reference to the query key of thsi record */
82 guint32 ttl; /**< DNS TTL of this record */
89 } generic; /**< Generic record data for unknown types */
96 } srv; /**< Data for SRV records */
100 } ptr; /**< Data for PTR an CNAME records */
105 } hinfo; /**< Data for HINFO records */
108 AvahiStringList *string_list;
109 } txt; /**< Data for TXT records */
112 AvahiIPv4Address address;
113 } a; /**< Data for A records */
116 AvahiIPv6Address address;
117 } aaaa; /**< Data for AAAA records */
119 } data; /**< Record data */
123 /** Create a new AvahiKey object. The reference counter will be set to 1. */
124 AvahiKey *avahi_key_new(const gchar *name, guint16 clazz, guint16 type);
126 /** Increase the reference counter of an AvahiKey object by one */
127 AvahiKey *avahi_key_ref(AvahiKey *k);
129 /** Decrease the reference counter of an AvahiKey object by one */
130 void avahi_key_unref(AvahiKey *k);
132 /** Check whether two AvahiKey object contain the same
133 * data. AVAHI_DNS_CLASS_ANY/AVAHI_DNS_TYPE_ANY are treated like any
134 * other class/type. */
135 gboolean avahi_key_equal(const AvahiKey *a, const AvahiKey *b);
137 /** Match a key to a key pattern. The pattern has a type of
138 AVAHI_DNS_CLASS_ANY, the classes are taken to be equal. Same for the
139 type. If the pattern has neither class nor type with ANY constants,
140 this function is identical to avahi_key_equal(). In contrast to
141 avahi_equal() this function is not commutative. */
142 gboolean avahi_key_pattern_match(const AvahiKey *pattern, const AvahiKey *k);
144 /** Check whether a key is a pattern key, i.e. the class/type has a
145 * value of AVAHI_DNS_CLASS_ANY/AVAHI_DNS_TYPE_ANY */
146 gboolean avahi_key_is_pattern(const AvahiKey *k);
148 /** Return a numeric hash value for a key for usage in hash tables. */
149 guint avahi_key_hash(const AvahiKey *k);
151 /** Create a new record object. Record data should be filled in right after creation. The reference counter is set to 1. */
152 AvahiRecord *avahi_record_new(AvahiKey *k, guint32 ttl);
154 /** Create a new record object. Record data should be filled in right after creation. The reference counter is set to 1. */
155 AvahiRecord *avahi_record_new_full(const gchar *name, guint16 clazz, guint16 type, guint32 ttl);
157 /** Increase the reference counter of an AvahiRecord by one. */
158 AvahiRecord *avahi_record_ref(AvahiRecord *r);
160 /** Decrease the reference counter of an AvahiRecord by one. */
161 void avahi_record_unref(AvahiRecord *r);
163 /** Return a textual representation of the specified DNS class. The
164 * returned pointer points to a read only internal string. */
165 const gchar *avahi_dns_class_to_string(guint16 clazz);
167 /** Return a textual representation of the specified DNS class. The
168 * returned pointer points to a read only internal string. */
169 const gchar *avahi_dns_type_to_string(guint16 type);
171 /** Create a textual representation of the specified key. g_free() the
173 gchar *avahi_key_to_string(const AvahiKey *k);
175 /** Create a textual representation of the specified record, similar
176 * in style to BIND zone file data. g_free() the result! */
177 gchar *avahi_record_to_string(const AvahiRecord *r);
179 /** Check whether two records are equal (regardless of the TTL */
180 gboolean avahi_record_equal_no_ttl(const AvahiRecord *a, const AvahiRecord *b);
182 /** Make a deep copy of an AvahiRecord object */
183 AvahiRecord *avahi_record_copy(AvahiRecord *r);
185 /** Returns a maximum estimate for the space that is needed to store
186 * this key in a DNS packet. */
187 guint avahi_key_get_estimate_size(AvahiKey *k);
189 /** Returns a maximum estimate for the space that is needed to store
190 * the record in a DNS packet. */
191 guint avahi_record_get_estimate_size(AvahiRecord *r);
193 /** Do a mDNS spec conforming lexicographical comparison of the two
194 * records. Return a negative value if a < b, a positive if a > b,
196 gint avahi_record_lexicographical_compare(AvahiRecord *a, AvahiRecord *b);
198 /** Return TRUE if the specified record is an mDNS goodbye record. i.e. TTL is zero. */
199 gboolean avahi_record_is_goodbye(AvahiRecord *r);
201 /** Check whether the specified key is valid */
202 gboolean avahi_key_valid(AvahiKey *k);
204 /** Check whether the specified record is valid */
205 gboolean avahi_record_valid(AvahiRecord *r);