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 /** \file core.h The Avahi Multicast DNS and DNS Service Discovery implmentation. */
29 #include <avahi-common/cdecl.h>
33 /** An mDNS responder object */
34 typedef struct AvahiServer AvahiServer;
36 /** A locally registered DNS resource record */
37 typedef struct AvahiEntry AvahiEntry;
39 /** A group of locally registered DNS RRs */
40 typedef struct AvahiEntryGroup AvahiEntryGroup;
44 #include <avahi-common/address.h>
45 #include <avahi-common/rr.h>
46 #include <avahi-common/alternative.h>
50 /** States of a server object */
52 AVAHI_SERVER_INVALID = -1, /**< Invalid state (initial) */
53 AVAHI_SERVER_REGISTERING = 0, /**< Host RRs are being registered */
54 AVAHI_SERVER_RUNNING, /**< All host RRs have been established */
55 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 All host RRs have been withdrawn, the user should set a new host name via avahi_server_set_host_name() */
56 AVAHI_SERVER_SLEEPING /**< The host or domain name has changed and the server waits for old entries to be expired */
59 /** Flags for server entries */
61 AVAHI_ENTRY_NULL = 0, /**< No special flags */
62 AVAHI_ENTRY_UNIQUE = 1, /**< The RRset is intended to be unique */
63 AVAHI_ENTRY_NOPROBE = 2, /**< Though the RRset is intended to be unique no probes shall be sent */
64 AVAHI_ENTRY_NOANNOUNCE = 4, /**< Do not announce this RR to other hosts */
65 AVAHI_ENTRY_ALLOWMUTIPLE = 8 /**< Allow multiple local records of this type, even if they are intended to be unique */
68 /** States of an entry group object */
70 AVAHI_ENTRY_GROUP_UNCOMMITED = -1, /**< The group has not yet been commited, the user must still call avahi_entry_group_commit() */
71 AVAHI_ENTRY_GROUP_REGISTERING = 0, /**< The entries of the group are currently being registered */
72 AVAHI_ENTRY_GROUP_ESTABLISHED, /**< The entries have successfully been established */
73 AVAHI_ENTRY_GROUP_COLLISION /**< A name collision for one of the entries in the group has been detected, the entries have been withdrawn */
74 } AvahiEntryGroupState;
76 /** Prototype for callback functions which are called whenever the state of an AvahiServer object changes */
77 typedef void (*AvahiServerCallback) (AvahiServer *s, AvahiServerState state, gpointer userdata);
79 /** Prototype for callback functions which are called whenever the state of an AvahiEntryGroup object changes */
80 typedef void (*AvahiEntryGroupCallback) (AvahiServer *s, AvahiEntryGroup *g, AvahiEntryGroupState state, gpointer userdata);
82 /** Stores configuration options for a server instance */
83 typedef struct AvahiServerConfig {
84 gchar *host_name; /**< Default host name. If left empty defaults to the result of gethostname(2) of the libc */
85 gchar *domain_name; /**< Default domain name. If left empty defaults to .local */
86 gboolean use_ipv4; /**< Enable IPv4 support */
87 gboolean use_ipv6; /**< Enable IPv6 support */
88 gboolean publish_hinfo; /**< Register a HINFO record for the host containing the local OS and CPU type */
89 gboolean publish_addresses; /**< Register A, AAAA and PTR records for all local IP addresses */
90 gboolean publish_workstation; /**< Register a _workstation._tcp service */
91 gboolean publish_domain; /**< Announce the local domain for browsing */
92 gboolean check_response_ttl; /**< If enabled the server ignores all incoming responses with IP TTL != 255. Newer versions of the RFC do no longer contain this check, so it is disabled by default. */
93 gboolean use_iff_running; /**< Require IFF_RUNNING on local network interfaces. This is the official way to check for link beat. Unfortunately this doesn't work with all drivers. So bettere leave this off. */
94 gboolean enable_reflector; /**< Reflect incoming mDNS traffic to all local networks. This allows mDNS based network browsing beyond ethernet borders */
95 gboolean reflect_ipv; /**< if enable_reflector is TRUE, enable/disable reflecting between IPv4 and IPv6 */
98 /** Allocate a new mDNS responder object. */
99 AvahiServer *avahi_server_new(
100 GMainContext *c, /**< The GLIB main loop context to attach to */
101 const AvahiServerConfig *sc, /**< If non-NULL a pointer to a configuration structure for the server. The server makes an internal deep copy of this structure, so you may free it using avahi_server_config_done() immediately after calling this function. */
102 AvahiServerCallback callback, /**< A callback which is called whenever the state of the server changes */
103 gpointer userdata /**< An opaque pointer which is passed to the callback function */);
105 /** Free an mDNS responder object */
106 void avahi_server_free(AvahiServer* s);
108 /** Fill in default values for a server configuration structure. If you
109 * make use of an AvahiServerConfig structure be sure to initialize
110 * it with this function for the sake of upwards library
111 * compatibility. This call may allocate strings on the heap. To
112 * release this memory make sure to call
113 * avahi_server_config_done(). If you want to replace any strings in
114 * the structure be sure to free the strings filled in by this
115 * function with g_free() first and allocate the replacements with
116 * g_malloc() (or g_strdup()).*/
117 AvahiServerConfig* avahi_server_config_init(
118 AvahiServerConfig *c /**< A structure which shall be filled in */ );
120 /** Make a deep copy of the configuration structure *c to *ret. */
121 AvahiServerConfig* avahi_server_config_copy(
122 AvahiServerConfig *ret /**< destination */,
123 const AvahiServerConfig *c /**< source */);
125 /** Free the data in a server configuration structure. */
126 void avahi_server_config_free(AvahiServerConfig *c);
128 /** Return the currently chosen domain name of the server object. The
129 * return value points to an internally allocated string. Be sure to
130 * make a copy of the string before calling any other library
132 const gchar* avahi_server_get_domain_name(AvahiServer *s);
134 /** Return the currently chosen host name. The return value points to a internally allocated string. */
135 const gchar* avahi_server_get_host_name(AvahiServer *s);
137 /** Return the currently chosen host name as a FQDN ("fully qualified
138 * domain name", i.e. the concatenation of the host and domain
139 * name). The return value points to a internally allocated string. */
140 const gchar* avahi_server_get_host_name_fqdn(AvahiServer *s);
142 /** Change the host name of a running mDNS responder. This will drop
143 all automicatilly generated RRs and readd them with the new
144 name. Since the responder has to probe for the new RRs this function
145 takes some time to take effect altough it returns immediately. This
146 function is intended to be called when a host name conflict is
147 reported using AvahiServerCallback. The caller should readd all user
148 defined RRs too since they otherwise continue to point to the outdated
150 gint avahi_server_set_host_name(AvahiServer *s, const gchar *host_name);
152 /** Change the domain name of a running mDNS responder. The same rules
153 * as with avahi_server_set_host_name() apply. */
154 gint avahi_server_set_domain_name(AvahiServer *s, const gchar *domain_name);
156 /** Return the opaque user data pointer attached to a server object */
157 gpointer avahi_server_get_data(AvahiServer *s);
159 /** Change the opaque user data pointer attached to a server object */
160 void avahi_server_set_data(AvahiServer *s, gpointer userdata);
162 /** Return the current state of the server object */
163 AvahiServerState avahi_server_get_state(AvahiServer *s);
165 /** Iterate through all local entries of the server. (when g is NULL)
166 * or of a specified entry group. At the first call state should point
167 * to a NULL initialized void pointer, That pointer is used to track
168 * the current iteration. It is not safe to call any other
169 * avahi_server_xxx() function during the iteration. If the last entry
170 * has been read, NULL is returned. */
171 const AvahiRecord *avahi_server_iterate(AvahiServer *s, AvahiEntryGroup *g, void **state);
173 /** Callback prototype for avahi_server_dump() */
174 typedef void (*AvahiDumpCallback)(const gchar *text, gpointer userdata);
176 /** Dump the current server status by calling "callback" for each line. */
177 void avahi_server_dump(AvahiServer *s, AvahiDumpCallback callback, gpointer userdata);
179 /** Create a new entry group. The specified callback function is
180 * called whenever the state of the group changes. Use entry group
181 * objects to keep track of you RRs. Add new RRs to a group using
182 * avahi_server_add_xxx(). Make sure to call avahi_entry_group_commit()
183 * to start the registration process for your RRs */
184 AvahiEntryGroup *avahi_entry_group_new(AvahiServer *s, AvahiEntryGroupCallback callback, gpointer userdata);
186 /** Free an entry group. All RRs assigned to the group are removed from the server */
187 void avahi_entry_group_free(AvahiEntryGroup *g);
189 /** Commit an entry group. This starts the probing and registration process for all RRs in the group */
190 gint avahi_entry_group_commit(AvahiEntryGroup *g);
192 /** Return the current state of the specified entry group */
193 AvahiEntryGroupState avahi_entry_group_get_state(AvahiEntryGroup *g);
195 /** Change the opaque user data pointer attached to an entry group object */
196 void avahi_entry_group_set_data(AvahiEntryGroup *g, gpointer userdata);
198 /** Return the opaque user data pointer currently set for the entry group object */
199 gpointer avahi_entry_group_get_data(AvahiEntryGroup *g);
201 /** Add a new resource record to the server. Returns 0 on success, negative otherwise. */
202 gint avahi_server_add(
203 AvahiServer *s, /**< The server object to add this record to */
204 AvahiEntryGroup *g, /**< An entry group object if this new record shall be attached to one, or NULL. If you plan to remove the record sometime later you a required to pass an entry group object here. */
205 AvahiIfIndex interface, /**< A numeric index of a network interface to attach this record to, or AVAHI_IF_UNSPEC to attach this record to all interfaces */
206 AvahiProtocol protocol, /**< A protocol family to attach this record to. One of the AVAHI_PROTO_xxx constants. Use AVAHI_PROTO_UNSPEC to make this record available on all protocols (wich means on both IPv4 and IPv6). */
207 AvahiEntryFlags flags, /**< Special flags for this record */
208 AvahiRecord *r /**< The record to add. This function increases the reference counter of this object. */ );
210 /** Add a PTR RR to the server. See avahi_server_add() for more information. */
211 gint avahi_server_add_ptr(
214 AvahiIfIndex interface,
215 AvahiProtocol protocol,
216 AvahiEntryFlags flags,
217 guint32 ttl, /**< DNS TTL for this record */
218 const gchar *name, /**< PTR record name */
219 const gchar *dest /**< pointer destination */ );
221 /** Add a PTR RR to the server. See avahi_server_add() for more information. */
222 gint avahi_server_add_txt(
225 AvahiIfIndex interface,
226 AvahiProtocol protocol,
227 AvahiEntryFlags flags,
228 guint32 ttl, /**< DNS TTL for this record */
229 const gchar *name, /**< TXT record name */
230 ... /**< Text record data, terminated by NULL */);
232 /** Add a PTR RR to the server. Mostly identical to
233 * avahi_server_add_text but takes a va_list instead of a variable
234 * number of arguments */
235 gint avahi_server_add_txt_va(
238 AvahiIfIndex interface,
239 AvahiProtocol protocol,
240 AvahiEntryFlags flags,
245 /** Add a PTR RR to the server. Mostly identical to
246 * avahi_server_add_text but takes an AvahiStringList record instead of a variable
247 * number of arguments. */
248 gint avahi_server_add_txt_strlst(
251 AvahiIfIndex interface,
252 AvahiProtocol protocol,
253 AvahiEntryFlags flags,
256 AvahiStringList *strlst /**< TXT decord data as a AvahiString. This routine makes a deep copy of this object. */ );
258 /** Add an IP address mapping to the server. This will add both the
259 * host-name-to-address and the reverse mapping to the server. See
260 * avahi_server_add() for more information. If adding one of the RRs
261 * fails, the function returns with an error, but it is not defined if
262 * the other RR is deleted from the server or not. Therefore, you have
263 * to free the AvahiEntryGroup and create a new one before
265 gint avahi_server_add_address(
268 AvahiIfIndex interface,
269 AvahiProtocol protocol,
270 AvahiEntryFlags flags,
274 /** Add an DNS-SD service to the Server. This will add all required
275 * RRs to the server. See avahi_server_add() for more information. If
276 * adding one of the RRs fails, the function returns with an error,
277 * but it is not defined if the other RR is deleted from the server or
278 * not. Therefore, you have to free the AvahiEntryGroup and create a
279 * new one before proceeding. */
280 gint avahi_server_add_service(
283 AvahiIfIndex interface,
284 AvahiProtocol protocol,
285 const gchar *name, /**< Service name, e.g. "Lennart's Files" */
286 const gchar *type, /**< DNS-SD type, e.g. "_http._tcp" */
288 const gchar *host, /**< Host name where this servcie resides, or NULL if on the local host */
289 guint16 port, /**< Port number of the service */
290 ... /**< Text records, terminated by NULL */);
292 /** Mostly identical to avahi_server_add_service(), but takes an va_list for the TXT records. */
293 gint avahi_server_add_service_va(
296 AvahiIfIndex interface,
297 AvahiProtocol protocol,
305 /** Mostly identical to avahi_server_add_service(), but takes an AvahiStringList object for the TXT records. The AvahiStringList object is copied. */
306 gint avahi_server_add_service_strlst(
309 AvahiIfIndex interface,
310 AvahiProtocol protocol,
316 AvahiStringList *strlst);
318 /** The type of DNS server */
320 AVAHI_DNS_SERVER_RESOLVE, /**< Unicast DNS servers for normal resolves (_domain._udp)*/
321 AVAHI_DNS_SERVER_UPDATE /**< Unicast DNS servers for updates (_dns-update._udp)*/
322 } AvahiDNSServerType;
324 /** Publish the specified unicast DNS server address via mDNS. You may
325 * browse for records create this way wit
326 * avahi_dns_server_browser_new(). */
327 gint avahi_server_add_dns_server_address(
330 AvahiIfIndex interface,
331 AvahiProtocol protocol,
333 AvahiDNSServerType type,
334 const AvahiAddress *address,
335 guint16 port /** should be 53 */);
337 /** Similar to avahi_server_add_dns_server_address(), but specify a
338 host name instead of an address. The specified host name should be
339 resolvable via mDNS */
340 gint avahi_server_add_dns_server_name(
343 AvahiIfIndex interface,
344 AvahiProtocol protocol,
346 AvahiDNSServerType type,
348 guint16 port /** should be 53 */);
350 /** Type of callback event when browsing */
352 AVAHI_BROWSER_NEW = 0, /**< The object is new on the network */
353 AVAHI_BROWSER_REMOVE = -1 /**< The object has been removed from the network */
356 /** Type of callback event when resolving */
358 AVAHI_RESOLVER_FOUND = 0, /**< RR found, resolving successful */
359 AVAHI_RESOLVER_TIMEOUT = -1 /**< Noone responded within the timeout, resolving failed */
360 } AvahiResolverEvent;
362 /** A browsing object for arbitrary RRs */
363 typedef struct AvahiRecordBrowser AvahiRecordBrowser;
365 /** Callback prototype for AvahiRecordBrowser events */
366 typedef void (*AvahiRecordBrowserCallback)(
367 AvahiRecordBrowser *b, /**< The AvahiRecordBrowser object that is emitting this callback */
368 AvahiIfIndex interface, /**< Logical OS network interface number the record was found on */
369 AvahiProtocol protocol, /**< Protocol number the record was found. */
370 AvahiBrowserEvent event, /**< Browsing event, either AVAHI_BROWSER_NEW or AVAHI_BROWSER_REMOVE */
371 AvahiRecord *record, /**< The record that was found */
372 gpointer userdata /**< Arbitrary user data passed to avahi_record_browser_new() */ );
374 /** Create a new browsing object for arbitrary RRs */
375 AvahiRecordBrowser *avahi_record_browser_new(
376 AvahiServer *server, /**< The server object to which attach this query */
377 AvahiIfIndex interface, /**< Logical OS interface number where to look for the records, or AVAHI_IF_UNSPEC to look on interfaces */
378 AvahiProtocol protocol, /**< Protocol number to use when looking for the record, or AVAHI_PROTO_UNSPEC to look on all protocols */
379 AvahiKey *key, /**< The search key */
380 AvahiRecordBrowserCallback callback, /**< The callback to call on browsing events */
381 gpointer userdata /**< Arbitrary use suppliable data which is passed to the callback */);
383 /** Free an AvahiRecordBrowser object */
384 void avahi_record_browser_free(AvahiRecordBrowser *b);
386 /** A host name to IP adddress resolver object */
387 typedef struct AvahiHostNameResolver AvahiHostNameResolver;
389 /** Callback prototype for AvahiHostNameResolver events */
390 typedef void (*AvahiHostNameResolverCallback)(
391 AvahiHostNameResolver *r,
392 AvahiIfIndex interface,
393 AvahiProtocol protocol,
394 AvahiResolverEvent event, /**< Resolving event */
395 const gchar *host_name, /**< Host name which should be resolved. May differ in case from the query */
396 const AvahiAddress *a, /**< The address, or NULL if the host name couldn't be resolved. */
399 /** Create an AvahiHostNameResolver object for resolving a host name to an adddress. See AvahiRecordBrowser for more info on the paramters. */
400 AvahiHostNameResolver *avahi_host_name_resolver_new(
402 AvahiIfIndex interface,
403 AvahiProtocol protocol,
404 const gchar *host_name, /**< The host name to look for */
405 AvahiProtocol aprotocol, /**< The address family of the desired address or AVAHI_PROTO_UNSPEC if doesn't matter. */
406 AvahiHostNameResolverCallback calback,
409 /** Free a AvahiHostNameResolver object */
410 void avahi_host_name_resolver_free(AvahiHostNameResolver *r);
412 /** An IP address to host name resolver object ("reverse lookup") */
413 typedef struct AvahiAddressResolver AvahiAddressResolver;
415 /** Callback prototype for AvahiAddressResolver events */
416 typedef void (*AvahiAddressResolverCallback)(
417 AvahiAddressResolver *r,
418 AvahiIfIndex interface,
419 AvahiProtocol protocol,
420 AvahiResolverEvent event,
421 const AvahiAddress *a,
422 const gchar *host_name, /**< A host name for the specified address, if one was found, i.e. event == AVAHI_RESOLVER_FOUND */
425 /** Create an AvahiAddressResolver object. See AvahiRecordBrowser for more info on the paramters. */
426 AvahiAddressResolver *avahi_address_resolver_new(
428 AvahiIfIndex interface,
429 AvahiProtocol protocol,
430 const AvahiAddress *address,
431 AvahiAddressResolverCallback calback,
434 /** Free an AvahiAddressResolver object */
435 void avahi_address_resolver_free(AvahiAddressResolver *r);
437 /** The type of domain to browse for */
439 AVAHI_DOMAIN_BROWSER_REGISTER, /**< Browse for a list of available registering domains */
440 AVAHI_DOMAIN_BROWSER_REGISTER_DEFAULT, /**< Browse for the default registering domain */
441 AVAHI_DOMAIN_BROWSER_BROWSE, /**< Browse for a list of available browsing domains */
442 AVAHI_DOMAIN_BROWSER_BROWSE_DEFAULT, /**< Browse for the default browsing domain */
443 AVAHI_DOMAIN_BROWSER_BROWSE_LEGACY, /**< Legacy browse domain - see DNS-SD spec for more information */
444 AVAHI_DOMAIN_BROWSER_MAX
445 } AvahiDomainBrowserType;
447 /** A local domain browsing object. May be used to enumerate domains used on the local LAN */
448 typedef struct AvahiDomainBrowser AvahiDomainBrowser;
450 /** Callback prototype for AvahiDomainBrowser events */
451 typedef void (*AvahiDomainBrowserCallback)(
452 AvahiDomainBrowser *b,
453 AvahiIfIndex interface,
454 AvahiProtocol protocol,
455 AvahiBrowserEvent event,
459 /** Create a new AvahiDomainBrowser object */
460 AvahiDomainBrowser *avahi_domain_browser_new(
462 AvahiIfIndex interface,
463 AvahiProtocol protocol,
465 AvahiDomainBrowserType type,
466 AvahiDomainBrowserCallback callback,
469 /** Free an AvahiDomainBrowser object */
470 void avahi_domain_browser_free(AvahiDomainBrowser *b);
472 /** A DNS-SD service type browsing object. May be used to enumerate the service types of all available services on the local LAN */
473 typedef struct AvahiServiceTypeBrowser AvahiServiceTypeBrowser;
475 /** Callback prototype for AvahiServiceTypeBrowser events */
476 typedef void (*AvahiServiceTypeBrowserCallback)(
477 AvahiServiceTypeBrowser *b,
478 AvahiIfIndex interface,
479 AvahiProtocol protocol,
480 AvahiBrowserEvent event,
485 /** Create a new AvahiServiceTypeBrowser object. */
486 AvahiServiceTypeBrowser *avahi_service_type_browser_new(
488 AvahiIfIndex interface,
489 AvahiProtocol protocol,
491 AvahiServiceTypeBrowserCallback callback,
494 /** Free an AvahiServiceTypeBrowser object */
495 void avahi_service_type_browser_free(AvahiServiceTypeBrowser *b);
497 /** A DNS-SD service browser. Use this to enumerate available services of a certain kind on the local LAN. Use AvahiServiceResolver to get specific service data like address and port for a service. */
498 typedef struct AvahiServiceBrowser AvahiServiceBrowser;
500 /** Callback prototype for AvahiServiceBrowser events */
501 typedef void (*AvahiServiceBrowserCallback)(
502 AvahiServiceBrowser *b,
503 AvahiIfIndex interface,
504 AvahiProtocol protocol,
505 AvahiBrowserEvent event,
506 const gchar *name /**< Service name, e.g. "Lennart's Files" */,
507 const gchar *type /**< DNS-SD type, e.g. "_http._tcp" */,
508 const gchar *domain /**< Domain of this service, e.g. "local" */,
511 /** Create a new AvahiServiceBrowser object. */
512 AvahiServiceBrowser *avahi_service_browser_new(
514 AvahiIfIndex interface,
515 AvahiProtocol protocol,
516 const gchar *service_type /** DNS-SD service type, e.g. "_http._tcp" */,
518 AvahiServiceBrowserCallback callback,
521 /** Free an AvahiServiceBrowser object */
522 void avahi_service_browser_free(AvahiServiceBrowser *b);
524 /** A DNS-SD service resolver. Use this to retrieve addres, port and TXT data for a DNS-SD service */
525 typedef struct AvahiServiceResolver AvahiServiceResolver;
527 /** Callback prototype for AvahiServiceResolver events */
528 typedef void (*AvahiServiceResolverCallback)(
529 AvahiServiceResolver *r,
530 AvahiIfIndex interface,
531 AvahiProtocol protocol,
532 AvahiResolverEvent event,
533 const gchar *name, /**< Service name */
534 const gchar *type, /**< Service Type */
536 const gchar *host_name, /**< Host name of the service */
537 const AvahiAddress *a, /**< The resolved host name */
538 guint16 port, /**< Service name */
539 AvahiStringList *txt, /**< TXT record data */
542 /** Create a new AvahiServiceResolver object */
543 AvahiServiceResolver *avahi_service_resolver_new(
545 AvahiIfIndex interface,
546 AvahiProtocol protocol,
550 AvahiProtocol aprotocol, /**< Address family of the desired service address. Use AVAHI_PROTO_UNSPEC if you don't care */
551 AvahiServiceResolverCallback calback,
554 /** Free an AvahiServiceResolver object */
555 void avahi_service_resolver_free(AvahiServiceResolver *r);
557 /** A domain service browser object. Use this to browse for
558 * conventional unicast DNS servers which may be used to resolve
559 * conventional domain names */
560 typedef struct AvahiDNSServerBrowser AvahiDNSServerBrowser;
562 /** Callback prototype for AvahiDNSServerBrowser events */
563 typedef void (*AvahiDNSServerBrowserCallback)(
564 AvahiDNSServerBrowser *b,
565 AvahiIfIndex interface,
566 AvahiProtocol protocol,
567 AvahiBrowserEvent event,
568 const gchar *host_name, /**< Host name of the DNS server, probably useless */
569 const AvahiAddress *a, /**< Address of the DNS server */
570 guint16 port, /**< Port number of the DNS servers, probably 53 */
573 /** Create a new AvahiDNSServerBrowser object */
574 AvahiDNSServerBrowser *avahi_dns_server_browser_new(
576 AvahiIfIndex interface,
577 AvahiProtocol protocol,
579 AvahiDNSServerType type,
580 AvahiProtocol aprotocol, /**< Address protocol for the DNS server */
581 AvahiDNSServerBrowserCallback callback,
584 /** Free an AvahiDNSServerBrowser object */
585 void avahi_dns_server_browser_free(AvahiDNSServerBrowser *b);