1 #ifndef foodefshfoo 2 #define foodefshfoo 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 defs.h Some common definitions */ 24 25 #include <avahi-common/cdecl.h> 26 27 /** \mainpage 28 * 29 * \section choose_api Choosing an API 30 * 31 * Avahi provides three programming APIs for integration of 32 * mDNS/DNS-SD features into your C progams: 33 * 34 * \li <b>avahi-core</b>: an API for embedding a complete mDNS/DNS-SD stack 35 * into your software. This is intended for developers of embedded 36 * appliances only. We dissuade from using this API in normal desktop 37 * applications since it is not a good idea to run multiple mDNS 38 * stacks simultaneously on the same host. 39 * \li <b>the D-Bus API</b>: an extensive D-Bus interface for browsing and 40 * registering mDNS/DNS-SD services using avahi-daemon. We recommend 41 * using this API for software written in any language other than 42 * C (e.g. Python). 43 * \li <b>avahi-client</b>: a simplifying C wrapper around the D-Bus API. We 44 * recommend using this API in C or C++ progams. The D-Bus internals 45 * are hidden completely. 46 * \li <b>avahi-gobject</b>: an object-oriented C wrapper based on 47 * GLib's GObject. We recommd using this API for GNOME/Gtk programs. 48 * 49 * All three APIs are very similar, however avahi-core is the most powerful. 50 * 51 * In addition to the three APIs described above Avahi supports two 52 * compatibility libraries: 53 * 54 * \li <b>avahi-compat-libdns_sd</b>: the original Bonjour API as documented 55 * in the header file "dns_sd.h" by Apple Computer, Inc. 56 * 57 * \li <b>avahi-compat-howl</b>: the HOWL API as released with HOWL 0.9.8 by 58 * Porchdog Software. 59 * 60 * Please note that these compatibility layers are incomplete and 61 * generally a waste of resources. We strongly encourage everyone to 62 * use our native APIs for newly written programs and to port older 63 * programs to avahi-client! 64 * 65 * The native APIs (avahi-client and avahi-core) can be integrated 66 * into external event loops. We provide adapters for the following 67 * event loop implementations: 68 * 69 * \li <b>avahi-glib</b>: The GLIB main loop as used by GTk+/GNOME 70 * 71 * \li <b>avahi-qt</b>: The Qt main loop as used by Qt/KDE 72 * 73 * Finally, we provide a high-level Gtk+ GUI dialog called 74 * <b>avahi-ui</b> for user-friendly browsing for services. 75 * 76 * The doxygen-generated API documentation covers avahi-client 77 * (including its auxiliary APIs), the event loop adapters and 78 * avahi-ui. For the other APIs please consult the original 79 * documentation (for the compatibility APIs) or the header files. 80 * 81 * Please note that the doxygen-generated API documentation of the 82 * native Avahi API is not complete. A few definitions that are part 83 * of the Avahi API have been removed from this documentation, either 84 * because they are only relevant in a very few low-level applications 85 * or because they are considered obsolete. Please consult the C header 86 * files for all definitions that are part of the Avahi API. Please 87 * note that these hidden definitions are considered part of the Avahi 88 * API and will stay available in the API in the future. 89 * 90 * \section error_reporting Error Reporting 91 * 92 * Some notes on the Avahi error handling: 93 * 94 * - Error codes are negative integers and defined as AVAHI_ERR_xx 95 * - If a function returns some kind of non-negative integer value on 96 * success, a failure is indicated by returning the error code 97 * directly. 98 * - If a function returns a pointer of some kind on success, a 99 * failure is indicated by returning NULL 100 * - The last error number may be retrieved by calling 101 * avahi_client_errno() 102 * - Just like the libc errno variable the Avahi errno is NOT reset to 103 * AVAHI_OK if a function call succeeds. 104 * - You may convert a numeric error code into a human readable string 105 * using avahi_strerror() 106 * - The constructor function avahi_client_new() returns the error 107 * code in a call-by-reference argument 108 * 109 * \section event_loop Event Loop Abstraction 110 * 111 * Avahi uses a simple event loop abstraction layer. A table AvahiPoll 112 * which contains function pointers for user defined timeout and I/O 113 * condition event source implementations needs to be passed to 114 * avahi_client_new(). An adapter for this abstraction layer is 115 * available for the GLib main loop in the object AvahiGLibPoll. A 116 * simple stand-alone implementation is available under the name 117 * AvahiSimplePoll. An adpater for the Qt main loop is available from 118 * avahi_qt_poll_get(). 119 * 120 * \section good_publish How to Register Services 121 * 122 * - Subscribe to server state changes. Pass a callback function 123 * pointer to avahi_client_new(). It will be called 124 * whenever the server state changes. 125 * - Only register your services when the server is in state 126 * AVAHI_SERVER_RUNNING. If you register your services in other server 127 * states they might not be accessible since the local host name might not necessarily 128 * be established. 129 * - Remove your services when the server enters 130 * AVAHI_SERVER_COLLISION or AVAHI_SERVER_REGISTERING state. Your 131 * services may not be reachable anymore since the local host name is 132 * no longer established or is currently in the process of being 133 * established. 134 * - When registering services, use the following algorithm: 135 * - Create a new entry group (i.e. avahi_entry_group_new()) 136 * - Add your service(s)/additional RRs/subtypes (e.g. avahi_entry_group_add_service()) 137 * - Commit the entry group (i.e. avahi_entry_group_commit()) 138 * - Subscribe to entry group state changes. 139 * - If the entry group enters AVAHI_ENTRY_GROUP_COLLISION state the 140 * services of the entry group are automatically removed from the 141 * server. You may immediately add your services back to the entry 142 * group (but with new names, perhaps using 143 * avahi_alternative_service_name()) and commit again. Please do not 144 * free the entry group and create a new one. This would inhibit some 145 * traffic limiting algorithms in mDNS. 146 * - When you need to modify your services (i.e. change the TXT data 147 * or the port number), use the AVAHI_PUBLISH_UPDATE flag. Please do 148 * not free the entry group and create a new one. This would inhibit 149 * some traffic limiting algorithms in mDNS. When changing just the 150 * TXT data avahi_entry_group_update_txt() is a shortcut for 151 * AVAHI_PUBLISH_UPDATE. Please note that you cannot use 152 * AVAHI_PUBLISH_UPDATE when changing the service name! Renaming a 153 * DNS-SD service is identical to deleting and creating a new one, and 154 * that's exactly what you should do in that case. First call 155 * avahi_entry_group_reset() to remove it and then read it normally. 156 * 157 * \section good_browse How to Browse for Services 158 * 159 * - For normal applications you need to call avahi_service_browser_new() 160 * for the service type you want to browse for. Use 161 * avahi_service_resolver_new() to acquire service data for a service 162 * name. 163 * - You can use avahi_domain_browser_new() to get a list of announced 164 * browsing domains. Please note that not all domains whith services 165 * on the LAN are mandatorily announced. 166 * - There is no need to subscribe to server state changes. 167 * 168 * \section daemon_dies How to Write a Client That Can Deal with Daemon Restarts 169 * 170 * With Avahi it is possible to write client applications that can 171 * deal with Avahi daemon restarts. To accomplish that make sure to 172 * pass AVAHI_CLIENT_NO_FAIL to avahi_client_new()'s flags 173 * parameter. That way avahi_client_new() will succeed even when the 174 * daemon is not running. In that case the object will enter 175 * AVAHI_CLIENT_CONNECTING state. As soon as the daemon becomes 176 * available the object will enter one of the AVAHI_CLIENT_S_xxx 177 * states. Make sure to not create browsers or entry groups before the 178 * client object has entered one of those states. As usual you will be 179 * informed about state changes with the callback function supplied to 180 * avahi_client_new(). If the client is forced to disconnect from the 181 * server it will enter AVAHI_CLIENT_FAILURE state with 182 * avahi_client_errno() == AVAHI_ERR_DISCONNECTED. Free the 183 * AvahiClient object in that case (and all its associated objects 184 * such as entry groups and browser objects prior to that) and 185 * reconnect to the server anew - again with passing 186 * AVAHI_CLIENT_NO_FAIL to avahi_client_new(). 187 * 188 * We encourage implementing this in all software where service 189 * discovery is not an integral part of application. e.g. use it in 190 * all kinds of background daemons, but not necessarily in software 191 * like iChat compatible IM software. 192 * 193 * For now AVAHI_CLIENT_NO_FAIL cannot deal with D-Bus daemon restarts. 194 * 195 * \section domains How to Deal Properly with Browsing Domains 196 * 197 * Due to the introduction of wide-area DNS-SD the correct handling of 198 * domains becomes more important for Avahi enabled applications. All 199 * applications that offer the user a list of services discovered with 200 * Avahi should offer some kind of editable drop down box where the 201 * user can either enter his own domain or select one of those offered 202 * by AvahiDomainBrowser. The default domain to browse should be the 203 * one returned by avahi_client_get_domain_name(). The list of domains 204 * returned by AvahiDomainBrowser is assembled by the browsing domains 205 * configured in the daemon's configuration file, the domains 206 * announced inside the default domain, the domains set with the 207 * environment variable $AVAHI_BROWSE_DOMAINS (colon-seperated) on the 208 * client side and the domains set in the XDG configuration file 209 * ~/.config/avahi/browse-domains on the client side (seperated by 210 * newlines). File managers offering some kind of "Network 211 * Neighborhood" folder should show the entries of the default domain 212 * right inside that and offer subfolders for the browsing domains 213 * returned by AvahiDomainBrowser. 214 */ 215 216 AVAHI_C_DECL_BEGIN 217 218 /** @{ \name States */ 219 220 /** States of a server object */ 221 typedef enum { 222 AVAHI_SERVER_INVALID, /**< Invalid state (initial) */ 223 AVAHI_SERVER_REGISTERING, /**< Host RRs are being registered */ 224 AVAHI_SERVER_RUNNING, /**< All host RRs have been established */ 225 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() */ 226 AVAHI_SERVER_FAILURE /**< Some fatal failure happened, the server is unable to proceed */ 227 } AvahiServerState; 228 229 /** States of an entry group object */ 230 typedef enum { 231 AVAHI_ENTRY_GROUP_UNCOMMITED, /**< The group has not yet been commited, the user must still call avahi_entry_group_commit() */ 232 AVAHI_ENTRY_GROUP_REGISTERING, /**< The entries of the group are currently being registered */ 233 AVAHI_ENTRY_GROUP_ESTABLISHED, /**< The entries have successfully been established */ 234 AVAHI_ENTRY_GROUP_COLLISION, /**< A name collision for one of the entries in the group has been detected, the entries have been withdrawn */ 235 AVAHI_ENTRY_GROUP_FAILURE /**< Some kind of failure happened, the entries have been withdrawn */ 236 } AvahiEntryGroupState; 237 238 /** @} */ 239 240 /** @{ \name Flags */ 241 242 /** Some flags for publishing functions */ 243 typedef enum { 244 AVAHI_PUBLISH_UNIQUE = 1, /**< For raw records: The RRset is intended to be unique */ 245 AVAHI_PUBLISH_NO_PROBE = 2, /**< For raw records: Though the RRset is intended to be unique no probes shall be sent */ 246 AVAHI_PUBLISH_NO_ANNOUNCE = 4, /**< For raw records: Do not announce this RR to other hosts */ 247 AVAHI_PUBLISH_ALLOW_MULTIPLE = 8, /**< For raw records: Allow multiple local records of this type, even if they are intended to be unique */ 248 /** \cond fulldocs */ 249 AVAHI_PUBLISH_NO_REVERSE = 16, /**< For address records: don't create a reverse (PTR) entry */ 250 AVAHI_PUBLISH_NO_COOKIE = 32, /**< For service records: do not implicitly add the local service cookie to TXT data */ 251 /** \endcond */ 252 AVAHI_PUBLISH_UPDATE = 64, /**< Update existing records instead of adding new ones */ 253 /** \cond fulldocs */ 254 AVAHI_PUBLISH_USE_WIDE_AREA = 128, /**< Register the record using wide area DNS (i.e. unicast DNS update) */ 255 AVAHI_PUBLISH_USE_MULTICAST = 256 /**< Register the record using multicast DNS */ 256 /** \endcond */ 257 } AvahiPublishFlags; 258 259 /** Some flags for lookup functions */ 260 typedef enum { 261 /** \cond fulldocs */ 262 AVAHI_LOOKUP_USE_WIDE_AREA = 1, /**< Force lookup via wide area DNS */ 263 AVAHI_LOOKUP_USE_MULTICAST = 2, /**< Force lookup via multicast DNS */ 264 /** \endcond */ 265 AVAHI_LOOKUP_NO_TXT = 4, /**< When doing service resolving, don't lookup TXT record */ 266 AVAHI_LOOKUP_NO_ADDRESS = 8 /**< When doing service resolving, don't lookup A/AAAA record */ 267 } AvahiLookupFlags; 268 269 /** Some flags for lookup callback functions */ 270 typedef enum { 271 AVAHI_LOOKUP_RESULT_CACHED = 1, /**< This response originates from the cache */ 272 AVAHI_LOOKUP_RESULT_WIDE_AREA = 2, /**< This response originates from wide area DNS */ 273 AVAHI_LOOKUP_RESULT_MULTICAST = 4, /**< This response originates from multicast DNS */ 274 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. */ 275 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. */ 276 AVAHI_LOOKUP_RESULT_STATIC = 32 /**< The returned data has been defined statically by some configuration option */ 277 } AvahiLookupResultFlags; 278 279 /** @} */ 280 281 /** @{ \name Events */ 282 283 /** Type of callback event when browsing */ 284 typedef enum { 285 AVAHI_BROWSER_NEW, /**< The object is new on the network */ 286 AVAHI_BROWSER_REMOVE, /**< The object has been removed from the network */ 287 AVAHI_BROWSER_CACHE_EXHAUSTED, /**< One-time event, to notify the user that all entries from the caches have been sent */ 288 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 */ 289 AVAHI_BROWSER_FAILURE /**< Browsing failed due to some reason which can be retrieved using avahi_server_errno()/avahi_client_errno() */ 290 } AvahiBrowserEvent; 291 292 /** Type of callback event when resolving */ 293 typedef enum { 294 AVAHI_RESOLVER_FOUND, /**< RR found, resolving successful */ 295 AVAHI_RESOLVER_FAILURE /**< Resolving failed due to some reason which can be retrieved using avahi_server_errno()/avahi_client_errno() */ 296 } AvahiResolverEvent; 297 298 /** @} */ 299 300 /** @{ \name Other definitions */ 301 302 /** The type of domain to browse for */ 303 typedef enum { 304 AVAHI_DOMAIN_BROWSER_BROWSE, /**< Browse for a list of available browsing domains */ 305 AVAHI_DOMAIN_BROWSER_BROWSE_DEFAULT, /**< Browse for the default browsing domain */ 306 AVAHI_DOMAIN_BROWSER_REGISTER, /**< Browse for a list of available registering domains */ 307 AVAHI_DOMAIN_BROWSER_REGISTER_DEFAULT, /**< Browse for the default registering domain */ 308 AVAHI_DOMAIN_BROWSER_BROWSE_LEGACY, /**< Legacy browse domain - see DNS-SD spec for more information */ 309 AVAHI_DOMAIN_BROWSER_MAX 310 } AvahiDomainBrowserType; 311 312 /** @} */ 313 314 /** \cond fulldocs */ 315 /** For every service a special TXT item is implicitly added, which 316 * contains a random cookie which is private to the local daemon. This 317 * can be used by clients to determine if two services on two 318 * different subnets are effectively the same. */ 319 #define AVAHI_SERVICE_COOKIE "org.freedesktop.Avahi.cookie" 320 321 /** In invalid cookie as special value */ 322 #define AVAHI_SERVICE_COOKIE_INVALID (0) 323 /** \endcond fulldocs */ 324 325 /** @{ \name DNS RR definitions */ 326 327 /** DNS record types, see RFC 1035 */ 328 enum { 329 AVAHI_DNS_TYPE_A = 0x01, 330 AVAHI_DNS_TYPE_NS = 0x02, 331 AVAHI_DNS_TYPE_CNAME = 0x05, 332 AVAHI_DNS_TYPE_SOA = 0x06, 333 AVAHI_DNS_TYPE_PTR = 0x0C, 334 AVAHI_DNS_TYPE_HINFO = 0x0D, 335 AVAHI_DNS_TYPE_MX = 0x0F, 336 AVAHI_DNS_TYPE_TXT = 0x10, 337 AVAHI_DNS_TYPE_AAAA = 0x1C, 338 AVAHI_DNS_TYPE_SRV = 0x21 339 }; 340 341 /** DNS record classes, see RFC 1035 */ 342 enum { 343 AVAHI_DNS_CLASS_IN = 0x01 /**< Probably the only class we will ever use */ 344 }; 345 346 /** @} */ 347 348 /** The default TTL for RRs which contain a host name of some kind. */ 349 #define AVAHI_DEFAULT_TTL_HOST_NAME (120) 350 351 /** The default TTL for all other records. */ 352 #define AVAHI_DEFAULT_TTL (75*60) 353 354 AVAHI_C_DECL_END 355 356 #endif 357