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
25 /** \file defs.h Some common definitions */
27 #include <avahi-common/cdecl.h>
31 * \section choose_api Choosing an API
33 * Avahi provides three programming APIs for integration of
34 * mDNS/DNS-SD features into your progams:
36 * \li avahi-core: an API for embedding a complete mDNS/DNS-SD stack
37 * into your software. This is intended for developers of embedded
38 * ampliances only. We dissuade from using this API in normal desktop
39 * applications since it is not a good idea to run multiple mDNS
40 * stacks simultaneously on the same host.
41 * \li The DBUS API: an extensive DBUS interface for browsing and
42 * registering mDNS/DNS-SD services using avahi-daemon. We recommend
43 * to use this API for software written in any language but
45 * \li avahi-client: a simplifying C wrapper around the DBUS API. We
46 * recommend to use this API in C or C++ progams. The DBUS internals
47 * are hidden completely.
49 * All three APIs are very similar, however avahi-core is the most powerful.
51 * \section error_reporting Error Reporting
53 * Some notes on the Avahi error handling:
55 * - Error codes are negative integers and defined as AVAHI_ERR_xx
56 * - If a function returns some kind of non-negative integer value
57 * on success, a failure is indicated by returning the error code
59 * - If a function returns a pointer of some kind on success, a
60 * failure is indicated by returning NULL
61 * - The last error number may be retrieved by calling
62 * avahi_server_errno() (for the server API) or avahi_client_errno()
63 * (for the client API)
64 * - Just like the libc errno variable the Avahi errno is NOT reset
65 * to AVAHI_OK if a function call succeeds.
66 * - You may convert a numeric error code into a human readable
67 * string using avahi_strerror()
68 * - The constructor functions avahi_server_new() and
69 * avahi_client_new() return the error code in a call-by-reference
72 * \section event_loop Event Loop Abstraction
74 * Avahi uses for both avahi-client and avahi-core a simple event loop
75 * abstraction layer.A table AvahiPoll which contains function
76 * pointers for user defined timeout and I/O condition event source
77 * implementations, needs to be passed to avahi_server_new() and
78 * avahi_client_new(). An adapter for this abstraction layer is
79 * available for the GLib main loop in the object AvahiGLibPoll. A
80 * simple stand-alone implementation is available under the name
83 * \section good_publish How to Register Services
85 * - Subscribe to server state changes. Pass a callback function
86 * pointer to avahi_client_new()/avahi_server_new(). It will be called
87 * whenever the server state changes.
88 * - Only register your services when the server is in state
89 * AVAHI_SERVER_RUNNING. If you register your services in other server
90 * states they might not be accessible since the local host name is
92 * - Remove your services when the server enters
93 * AVAHI_SERVER_COLLISION state. Your services may no be reachable
94 * anymore since the local host name is no longer established.
95 * - When registering services, use the following algorithm:
96 * - Create a new entry group (i.e. avahi_entry_group_new())
97 * - Add your service(s)/additional host names (i.e. avahi_entry_group_add_service())
98 * - Commit the entry group (i.e. avahi_entry_group_commit())
99 * - Subscribe to entry group state changes.
100 * - If the entry group enters AVAHI_ENTRY_GROUP_COLLISION state the
101 * services of the entry group are automatically removed from the
102 * server. You may immediately add your services back to the entry
103 * group (but with new names, perhaps using
104 * avahi_alternative_service_name()) and commit again. Please do not
105 * free the entry group and create a new one. This would inhibit some
106 * traffic limiting algorithms in mDNS.
107 * - When you need to modify your services, reset the entry group
108 * (i.e. avahi_entry_group_reset()) and add them back. Please do not
109 * free the entry group and create a new one. This would inhibit some
110 * traffic limiting algorithms in mDNS.
112 * The linked functions belong to avahi-client. They all have counterparts in the DBUS API and avahi-core.
114 * \section good_browse How to Browse for Services
116 * - For normal applications you need to call avahi_service_browser_new()
117 * for the service type you want to browse for. Use
118 * avahi_client_resolve_service() to acquire service data for a a service
120 * - You can use avahi_domain_browser() to get a list of announced
121 * browsing domains. Please note that not all domains whith services
122 * on the LAN are mandatorily announced.
123 * - Network monitor software may use avahi_service_type_browser_new()
124 * to browse for the list of available service types on the LAN. This
125 * API should NOT be used in normal software since it increases
127 * - There is no need to subscribe to server state changes.
129 * The linked functions belong to avahi-client. They all have counterparts in the DBUS API and avahi-core.
133 #ifndef DOXYGEN_SHOULD_SKIP_THIS
137 /** States of an entry group object */
139 AVAHI_ENTRY_GROUP_UNCOMMITED, /**< The group has not yet been commited, the user must still call avahi_entry_group_commit() */
140 AVAHI_ENTRY_GROUP_REGISTERING, /**< The entries of the group are currently being registered */
141 AVAHI_ENTRY_GROUP_ESTABLISHED, /**< The entries have successfully been established */
142 AVAHI_ENTRY_GROUP_COLLISION, /**< A name collision for one of the entries in the group has been detected, the entries have been withdrawn */
143 AVAHI_ENTRY_GROUP_FAILURE /**< Some kind of failure happened, the entries have been withdrawn */
144 } AvahiEntryGroupState;
146 /** The type of domain to browse for */
148 AVAHI_DOMAIN_BROWSER_REGISTER, /**< Browse for a list of available registering domains */
149 AVAHI_DOMAIN_BROWSER_REGISTER_DEFAULT, /**< Browse for the default registering domain */
150 AVAHI_DOMAIN_BROWSER_BROWSE, /**< Browse for a list of available browsing domains */
151 AVAHI_DOMAIN_BROWSER_BROWSE_DEFAULT, /**< Browse for the default browsing domain */
152 AVAHI_DOMAIN_BROWSER_BROWSE_LEGACY, /**< Legacy browse domain - see DNS-SD spec for more information */
153 AVAHI_DOMAIN_BROWSER_MAX
154 } AvahiDomainBrowserType;
156 /** Some flags for publishing functions */
158 AVAHI_PUBLISH_UNIQUE = 1, /**< For raw records: The RRset is intended to be unique */
159 AVAHI_PUBLISH_NO_PROBE = 2, /**< For raw records: Though the RRset is intended to be unique no probes shall be sent */
160 AVAHI_PUBLISH_NO_ANNOUNCE = 4, /**< For raw records: Do not announce this RR to other hosts */
161 AVAHI_PUBLISH_ALLOW_MULTIPLE = 8, /**< For raw records: Allow multiple local records of this type, even if they are intended to be unique */
162 AVAHI_PUBLISH_NO_REVERSE = 16, /**< For address records: don't create a reverse (PTR) entry */
163 AVAHI_PUBLISH_NO_COOKIE = 32, /**< For service records: do not implicitly add the local service cookie to TXT data */
164 AVAHI_PUBLISH_UPDATE = 64 /**< Update existing records instead of adding new ones */
167 /** Some flags for lookup functions */
169 AVAHI_LOOKUP_USE_WIDE_AREA = 1, /**< Force lookup via wide area DNS */
170 AVAHI_LOOKUP_USE_MULTICAST = 2, /**< Force lookup via multicast DNS */
171 AVAHI_LOOKUP_NO_TXT = 4, /**< When doing service resolving, don't lookup TXT record */
172 AVAHI_LOOKUP_NO_ADDRESS = 8 /**< When doing service resolving, don't lookup A/AAAA record */
175 /** Some flags for lookup callback functions */
177 AVAHI_LOOKUP_RESULT_CACHED = 1, /**< This response originates from the cache */
178 AVAHI_LOOKUP_RESULT_WIDE_AREA = 2, /**< This response originates from wide area DNS */
179 AVAHI_LOOKUP_RESULT_MULTICAST = 4, /**< This response originates from multicast DNS */
180 AVAHI_LOOKUP_RESULT_LOCAL = 8, /**< This record/service resides on and was announced by the local host. Only available in service and record browsers and only on AVAHI_BROWSER_NEW. */
181 AVAHI_LOOKUP_RESULT_OUR_OWN = 16 /**< This service belongs to the same local client as the browser object. Only available in avahi-client, and only for service browsers and only on AVAHI_BROWSER_NEW. */
182 } AvahiLookupResultFlags;
184 /** Type of callback event when browsing */
186 AVAHI_BROWSER_NEW, /**< The object is new on the network */
187 AVAHI_BROWSER_REMOVE, /**< The object has been removed from the network */
188 AVAHI_BROWSER_CACHE_EXHAUSTED, /**< One-time event, to notify the user that all entries from the caches have been send */
189 AVAHI_BROWSER_ALL_FOR_NOW, /**< One-time event, to notify the user that more records will probably not show up in the near future, i.e. all cache entries have been read and all static servers been queried */
190 AVAHI_BROWSER_FAILURE /**< Browsing failed due to some reason which can be retrieved using avahi_server_errno()/avahi_client_errno() */
193 /** Type of callback event when resolving */
195 AVAHI_RESOLVER_FOUND, /**< RR found, resolving successful */
196 AVAHI_RESOLVER_FAILURE /**< Resolving failed due to some reason which can be retrieved using avahi_server_errno()/avahi_client_errno() */
197 } AvahiResolverEvent;
199 /** States of a server object */
201 AVAHI_SERVER_INVALID, /**< Invalid state (initial) */
202 AVAHI_SERVER_REGISTERING, /**< Host RRs are being registered */
203 AVAHI_SERVER_RUNNING, /**< All host RRs have been established */
204 AVAHI_SERVER_COLLISION, /**< There is a collision with a host RR. All host RRs have been withdrawn, the user should set a new host name via avahi_server_set_host_name() */
205 AVAHI_SERVER_FAILURE /**< Some fatal failure happened, the server is unable to proceed */
208 /** For every service a special TXT item is implicitly added, which
209 * contains a random cookie which is private to the local daemon. This
210 * can be used by clients to determine if two services on two
211 * different subnets are effectively the same. */
212 #define AVAHI_SERVICE_COOKIE "org.freedesktop.Avahi.cookie"
214 /** In invalid cookie as special value */
215 #define AVAHI_SERVICE_COOKIE_INVALID (0)
217 #ifndef DOXYGEN_SHOULD_SKIP_THIS