X-Git-Url: http://git.meshlink.io/?a=blobdiff_plain;f=avahi-common%2Fdefs.h;h=4efa5ad5ab51955f91ed3096d47434d7d6d76666;hb=0456242ed7e6ad6bb2afd2f8210e86dfa80ab9d2;hp=67bdddc485dbfe9fed3522b89a174db501ee1907;hpb=6b391bb81f0dce0193a722254016b26c12a17643;p=catta diff --git a/avahi-common/defs.h b/avahi-common/defs.h index 67bdddc..4efa5ad 100644 --- a/avahi-common/defs.h +++ b/avahi-common/defs.h @@ -33,65 +33,79 @@ * Avahi provides three programming APIs for integration of * mDNS/DNS-SD features into your progams: * - * \li avahi-core: an API for embedding a complete mDNS/DNS-SD stack + * \li avahi-core: an API for embedding a complete mDNS/DNS-SD stack * into your software. This is intended for developers of embedded * ampliances only. We dissuade from using this API in normal desktop * applications since it is not a good idea to run multiple mDNS * stacks simultaneously on the same host. - * \li The DBUS API: an extensive DBUS interface for browsing and + * \li the D-Bus API: an extensive D-Bus interface for browsing and * registering mDNS/DNS-SD services using avahi-daemon. We recommend * to use this API for software written in any language but - * C. (i.e. python) - * \li avahi-client: a simplifying C wrapper around the DBUS API. We - * recommend to use this API in C or C++ progams. The DBUS internals + * C. (i.e. Python) + * \li avahi-client: a simplifying C wrapper around the D-Bus API. We + * recommend to use this API in C or C++ progams. The D-Bus internals * are hidden completely. * * All three APIs are very similar, however avahi-core is the most powerful. * + * In addition to the three APIs described above Avahi supports two + * compatibility libraries: + * + * \li avahi-compat-libdns_sd: the original Bonjour API as documented + * in the header file "dns_sd.h" by Apple Computer, Inc. + * + * \li avahi-compat-howl: the HOWL API as released with HOWL 0.9.8 by + * Porchdog Software. + * + * Please note that these compatibility layers are incomplete and + * generally a waste of resources. We strongly encourage everyone to + * use our native APIs for newly written programs and to port older + * programs to avahi-client! + * * \section error_reporting Error Reporting * * Some notes on the Avahi error handling: * * - Error codes are negative integers and defined as AVAHI_ERR_xx - * - If a function returns some kind of non-negative integer value - * on success, a failure is indicated by returning the error code + * - If a function returns some kind of non-negative integer value on + * success, a failure is indicated by returning the error code * directly. * - If a function returns a pointer of some kind on success, a * failure is indicated by returning NULL * - The last error number may be retrieved by calling - * avahi_server_errno() (for the server API) or avahi_client_errno() - * (for the client API) - * - Just like the libc errno variable the Avahi errno is NOT reset - * to AVAHI_OK if a function call succeeds. - * - You may convert a numeric error code into a human readable - * string using avahi_strerror() - * - The constructor functions avahi_server_new() and - * avahi_client_new() return the error code in a call-by-reference - * argument + * avahi_client_errno() + * - Just like the libc errno variable the Avahi errno is NOT reset to + * AVAHI_OK if a function call succeeds. + * - You may convert a numeric error code into a human readable string + * using avahi_strerror() + * - The constructor function avahi_client_new() returns the error + * code in a call-by-reference argument * * \section event_loop Event Loop Abstraction * - * Avahi uses for both avahi-client and avahi-core a simple event loop - * abstraction layer.A table AvahiPoll which contains function - * pointers for user defined timeout and I/O condition event source - * implementations, needs to be passed to avahi_server_new() and + * Avahi uses a simple event loop abstraction laye. A table AvahiPoll + * which contains function pointers for user defined timeout and I/O + * condition event source implementations needs to be passed to * avahi_client_new(). An adapter for this abstraction layer is * available for the GLib main loop in the object AvahiGLibPoll. A * simple stand-alone implementation is available under the name - * AvahiSimplePoll. + * AvahiSimplePoll. An adpater for the Qt main loop is available from + * avahi_qt_poll_get(). * * \section good_publish How to Register Services * * - Subscribe to server state changes. Pass a callback function - * pointer to avahi_client_new()/avahi_server_new(). It will be called + * pointer to avahi_client_new(). It will be called * whenever the server state changes. * - Only register your services when the server is in state * AVAHI_SERVER_RUNNING. If you register your services in other server * states they might not be accessible since the local host name is * not established. * - Remove your services when the server enters - * AVAHI_SERVER_COLLISION state. Your services may no be reachable - * anymore since the local host name is no longer established. + * AVAHI_SERVER_COLLISION or AVAHI_SERVER_REGISTERING state. Your + * services may no be reachable anymore since the local host name is + * no longer established or is currently in the process of being + * established. * - When registering services, use the following algorithm: * - Create a new entry group (i.e. avahi_entry_group_new()) * - Add your service(s)/additional host names (i.e. avahi_entry_group_add_service()) @@ -104,12 +118,16 @@ * avahi_alternative_service_name()) and commit again. Please do not * free the entry group and create a new one. This would inhibit some * traffic limiting algorithms in mDNS. - * - When you need to modify your services, reset the entry group - * (i.e. avahi_entry_group_reset()) and add them back. Please do not - * free the entry group and create a new one. This would inhibit some - * traffic limiting algorithms in mDNS. - * - * The linked functions belong to avahi-client. They all have counterparts in the DBUS API and avahi-core. + * - When you need to modify your services (i.e. change the TXT data + * or the port number), use the AVAHI_PUBLISH_UPDATE flag. Please do + * not free the entry group and create a new one. This would inhibit + * some traffic limiting algorithms in mDNS. When changing just the + * TXT data avahi_entry_group_update_txt() is a shortcut for + * AVAHI_PUBLISH_UPDATE. Please note that you cannot use + * AVAHI_PUBLISH_UPDATE when changing the service name! Renaming a + * DNS-SD service is identical to deleting and creating a new one, and + * that's exactly what you should do in that case. First call + * avahi_entry_group_reset() to remove it and than readd it normally. * * \section good_browse How to Browse for Services * @@ -117,56 +135,99 @@ * for the service type you want to browse for. Use * avahi_client_resolve_service() to acquire service data for a a service * name. - * - You can use avahi_domain_browser() to get a list of announced + * - You can use avahi_domain_browser_new() to get a list of announced * browsing domains. Please note that not all domains whith services * on the LAN are mandatorily announced. * - Network monitor software may use avahi_service_type_browser_new() * to browse for the list of available service types on the LAN. This * API should NOT be used in normal software since it increases - * traffic heavily. + * traffic immensly. In addition not all DNS-SD implementations + * announce their services in away that they can be found with + * avahi_server_type_browser_new(). * - There is no need to subscribe to server state changes. - * - * The linked functions belong to avahi-client. They all have counterparts in the DBUS API and avahi-core. - * + * + * \section daemon_dies How to Write a Client That Can Deal with Daemon Restarts + * + * With Avahi it is possible to write client applications that can + * deal with Avahi daemon restarts. To accomplish that make sure to + * pass AVAHI_CLIENT_NO_FAIL to avahi_client_new()'s flags + * parameter. That way avahi_client_new() will succeed even when the + * daemon is not running. In that case the object will enter + * AVAHI_CLIENT_CONNECTING state. As soon as the daemon becomes + * available the object will enter one of the AVAHI_CLIENT_S_xxx + * states. Make sure to not create browsers or entry groups before the + * client object has entered one of those states. As usual you will be + * informed about state changes with the callback function supplied to + * avahi_client_new(). If the client is forced to disconnect from the + * server it will enter AVAHI_CLIENT_FAILURE state with + * avahi_client_errno() == AVAHI_ERR_DISCONNECTED. Free the + * AvahiClient object in that case and reconnect to the server anew - + * again with passing AVAHI_CLIENT_NO_FAIL to avahi_client_new(). + * + * We encourage to implement this in all software where service + * discovery is not an integral part of application. e.g. use it in + * all kinds of background daemons, but not in software like iChat + * compatible IM software. + * + * For now AVAHI_CLIENT_NO_FAIL cannot deal with D-Bus daemon restarts. + * + * \section domains How to Deal Properly with Browsing Domains + * + * Due to the introduction of wide-area DNS-SD the correct handling of + * domains becomes more important for Avahi enabled applications. All + * applications that offer the user a list of services discovered with + * Avahi should offer some kind of editable drop down box where the + * user can either enter his own domain or select one of those offered + * by AvahiDomainBrowser. The default domain to browse should be the + * one returned by avahi_client_get_domain_name(). The list of domains + * returned by AvahiDomainBrowser is assembled by the browsing domains + * configured in the daemon's configuration file, the domains + * announced inside the default domain, the domains set with the + * environment variable $AVAHI_BROWSE_DOMAINS (colon-seperated) on the + * client side and the domains set in the XDG configuration file + * ~/.config/avahi/browse-domains on the client side (seperated by + * newlines). File managers offering some kind of "Network + * Neighborhood" folder should show the entries of the default domain + * right inside that and offer subfolders for the browsing domains + * returned by AvahiDomainBrowser. */ -#ifndef DOXYGEN_SHOULD_SKIP_THIS AVAHI_C_DECL_BEGIN -#endif /** States of an entry group object */ typedef enum { AVAHI_ENTRY_GROUP_UNCOMMITED, /**< The group has not yet been commited, the user must still call avahi_entry_group_commit() */ AVAHI_ENTRY_GROUP_REGISTERING, /**< The entries of the group are currently being registered */ AVAHI_ENTRY_GROUP_ESTABLISHED, /**< The entries have successfully been established */ - AVAHI_ENTRY_GROUP_COLLISION /**< A name collision for one of the entries in the group has been detected, the entries have been withdrawn */ + AVAHI_ENTRY_GROUP_COLLISION, /**< A name collision for one of the entries in the group has been detected, the entries have been withdrawn */ + AVAHI_ENTRY_GROUP_FAILURE /**< Some kind of failure happened, the entries have been withdrawn */ } AvahiEntryGroupState; /** The type of domain to browse for */ typedef enum { - AVAHI_DOMAIN_BROWSER_REGISTER, /**< Browse for a list of available registering domains */ - AVAHI_DOMAIN_BROWSER_REGISTER_DEFAULT, /**< Browse for the default registering domain */ AVAHI_DOMAIN_BROWSER_BROWSE, /**< Browse for a list of available browsing domains */ AVAHI_DOMAIN_BROWSER_BROWSE_DEFAULT, /**< Browse for the default browsing domain */ + AVAHI_DOMAIN_BROWSER_REGISTER, /**< Browse for a list of available registering domains */ + AVAHI_DOMAIN_BROWSER_REGISTER_DEFAULT, /**< Browse for the default registering domain */ AVAHI_DOMAIN_BROWSER_BROWSE_LEGACY, /**< Legacy browse domain - see DNS-SD spec for more information */ AVAHI_DOMAIN_BROWSER_MAX } AvahiDomainBrowserType; /** Some flags for publishing functions */ typedef enum { - AVAHI_PUBLISH_NULL = 0, AVAHI_PUBLISH_UNIQUE = 1, /**< For raw records: The RRset is intended to be unique */ AVAHI_PUBLISH_NO_PROBE = 2, /**< For raw records: Though the RRset is intended to be unique no probes shall be sent */ AVAHI_PUBLISH_NO_ANNOUNCE = 4, /**< For raw records: Do not announce this RR to other hosts */ AVAHI_PUBLISH_ALLOW_MULTIPLE = 8, /**< For raw records: Allow multiple local records of this type, even if they are intended to be unique */ AVAHI_PUBLISH_NO_REVERSE = 16, /**< For address records: don't create a reverse (PTR) entry */ AVAHI_PUBLISH_NO_COOKIE = 32, /**< For service records: do not implicitly add the local service cookie to TXT data */ - AVAHI_PUBLISH_UPDATE = 64 /**< Update existing records instead of adding new ones */ + AVAHI_PUBLISH_UPDATE = 64, /**< Update existing records instead of adding new ones */ + AVAHI_PUBLISH_USE_WIDE_AREA = 128, /**< Register the record using wide area DNS (i.e. unicast DNS update) */ + AVAHI_PUBLISH_USE_MULTICAST = 256 /**< Register the record using multicast DNS */ } AvahiPublishFlags; /** Some flags for lookup functions */ typedef enum { - AVAHI_LOOKUP_NULL = 0, AVAHI_LOOKUP_USE_WIDE_AREA = 1, /**< Force lookup via wide area DNS */ AVAHI_LOOKUP_USE_MULTICAST = 2, /**< Force lookup via multicast DNS */ AVAHI_LOOKUP_NO_TXT = 4, /**< When doing service resolving, don't lookup TXT record */ @@ -175,12 +236,12 @@ typedef enum { /** Some flags for lookup callback functions */ typedef enum { - AVAHI_LOOKUP_RESULT_NULL = 0, AVAHI_LOOKUP_RESULT_CACHED = 1, /**< This response originates from the cache */ AVAHI_LOOKUP_RESULT_WIDE_AREA = 2, /**< This response originates from wide area DNS */ AVAHI_LOOKUP_RESULT_MULTICAST = 4, /**< This response originates from multicast DNS */ 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. */ - 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. */ + 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. */ + AVAHI_LOOKUP_RESULT_STATIC = 32 /**< The returned data has been defined statically by some configuration option */ } AvahiLookupResultFlags; /** Type of callback event when browsing */ @@ -203,7 +264,8 @@ typedef enum { AVAHI_SERVER_INVALID, /**< Invalid state (initial) */ AVAHI_SERVER_REGISTERING, /**< Host RRs are being registered */ AVAHI_SERVER_RUNNING, /**< All host RRs have been established */ - 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() */ + 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() */ + AVAHI_SERVER_FAILURE /**< Some fatal failure happened, the server is unable to proceed */ } AvahiServerState; /** For every service a special TXT item is implicitly added, which @@ -215,8 +277,31 @@ typedef enum { /** In invalid cookie as special value */ #define AVAHI_SERVICE_COOKIE_INVALID (0) -#ifndef DOXYGEN_SHOULD_SKIP_THIS +/** DNS record types, see RFC 1035 */ +enum { + AVAHI_DNS_TYPE_A = 0x01, + AVAHI_DNS_TYPE_NS = 0x02, + AVAHI_DNS_TYPE_CNAME = 0x05, + AVAHI_DNS_TYPE_SOA = 0x06, + AVAHI_DNS_TYPE_PTR = 0x0C, + AVAHI_DNS_TYPE_HINFO = 0x0D, + AVAHI_DNS_TYPE_MX = 0x0F, + AVAHI_DNS_TYPE_TXT = 0x10, + AVAHI_DNS_TYPE_AAAA = 0x1C, + AVAHI_DNS_TYPE_SRV = 0x21, +}; + +/** DNS record classes, see RFC 1035 */ +enum { + AVAHI_DNS_CLASS_IN = 0x01, /**< Probably the only class we will ever use */ +}; + +/** The default TTL for RRs which contain a host name of some kind. */ +#define AVAHI_DEFAULT_TTL_HOST_NAME (120) + +/** The default TTL for all other records. */ +#define AVAHI_DEFAULT_TTL (75*60) + AVAHI_C_DECL_END -#endif #endif