/* * Copyright (c) 2003 Jeremie Miller * Copyright (c) 2016-2026 Joachim Wiberg * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * Neither the name of the copyright holders nor the names of its * contributors may be used to endorse or promote products derived from * this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ #ifndef LIB_MDNSD_H_ #define LIB_MDNSD_H_ #include "1035.h" #include "inet.h" #include #include #include #include #define QCLASS_IN (1) #define DISCO_NAME "_services._dns-sd._udp.local." #define DBG(fmt, args...) mdnsd_log(LOG_DEBUG, "%s(): " fmt, __func__, ##args) #define INFO(fmt, args...) mdnsd_log(LOG_INFO, "%s(): " fmt, __func__, ##args) #define NOTE(fmt, args...) mdnsd_log(LOG_NOTICE, fmt, ##args) #define WARN(fmt, args...) mdnsd_log(LOG_WARNING, fmt, ##args) #define ERR(fmt, args...) mdnsd_log(LOG_ERR, fmt, ##args) /* Main daemon data */ typedef struct mdns_daemon mdns_daemon_t; /* Record entry */ typedef struct mdns_record mdns_record_t; /* Callback for received record. Data is passed from the register call */ typedef void (*mdnsd_record_received_callback)(const struct resource* r, void* data); /* Answer data */ typedef struct mdns_answer { char *name; unsigned short int type; unsigned long int ttl; unsigned short int rdlen; unsigned char *rdata; struct in_addr ip; /* A, network byte order */ struct in6_addr ip6; /* AAAA, network byte order */ char *rdname; /* NS/CNAME/PTR/SRV */ struct { unsigned short int priority, weight, port; } srv; /* SRV */ } mdns_answer_t; /** * Global functions */ /** * Enable logging to syslog, stdout/stderr is used by default */ void mdnsd_log_open(const char *ident); /** * Adjust log level, by default LOG_NOTICE */ int mdnsd_log_level(char *level); /** * Log current time to DBG() or buf */ void mdnsd_log_time(struct timeval *tv, char *buf, size_t len); /** * HEX dump a buffer to log */ void mdnsd_log_hex(const char *msg, unsigned char *buffer, ssize_t len); /** * Log to syslog or stdio */ void mdnsd_log(int severity, const char *fmt, ...); /** * Create a new mdns daemon for the given class of names (usually 1) and * maximum frame size */ mdns_daemon_t *mdnsd_new(int class, int frame); /** * Set the daemon's transport address family, AF_INET (default) or * AF_INET6. Selects the multicast group mdnsd_out() targets. */ void mdnsd_set_family(mdns_daemon_t *d, sa_family_t family); /** * Control whether replies originating from this host are processed. On by * default, so mdnsd_in() (and hence mquery) sees a responder on the same * host; disable to skip the local host, like avahi-browse(1) -l. */ void mdnsd_set_local(mdns_daemon_t *d, int enable); /** * Get the current local-processing setting, see mdnsd_set_local() */ int mdnsd_get_local(mdns_daemon_t *d); /** * Set mDNS daemon host IP address */ void mdnsd_set_address(mdns_daemon_t *d, struct in_addr addr); /** * Get mDNS daemon host IP address from previous set */ struct in_addr mdnsd_get_address(mdns_daemon_t *d); /** * Set mDNS daemon host IPv6 address */ void mdnsd_set_ipv6_address(mdns_daemon_t *d, struct in6_addr addr); /** * Get mDNS daemon host IPv6 address from previous set */ struct in6_addr mdnsd_get_ipv6_address(mdns_daemon_t *d); /** * Gracefully shutdown the daemon, use mdnsd_out() to get the last * packets */ void mdnsd_shutdown(mdns_daemon_t *d); /** * Flush all cached records (network/interface changed) */ void mdnsd_flush(mdns_daemon_t *d); /** * Free given mdns_daemon_t *(should have used mdnsd_shutdown() first!) */ void mdnsd_free(mdns_daemon_t *d); /** * Register callback which is called when a record is received. The data parameter is passed to the callback. * Calling this multiple times overwrites the previous register. */ void mdnsd_register_receive_callback(mdns_daemon_t *d, mdnsd_record_received_callback cb, void *data); /** * I/O functions */ /** * Oncoming message from host (to be cached/processed) */ int mdnsd_in(mdns_daemon_t *d, struct message *m, const inet_addr_t *from); /** * Outgoing messge to be delivered to host, returns >0 if one was * returned and m/to set */ int mdnsd_out(mdns_daemon_t *d, struct message *m, inet_addr_t *to); /** * returns the max wait-time until mdnsd_out() needs to be called again */ struct timeval *mdnsd_sleep(mdns_daemon_t *d); /** * Q/A functions */ /** * Register a new query * * The answer() callback is called whenever one is found/changes/expires * (immediate or anytime after, mdns_answer_t valid until ->ttl==0) * either answer returns -1, or another mdnsd_query() with a %NULL answer * will remove/unregister this query */ void mdnsd_query(mdns_daemon_t *d, const char *host, int type, int (*answer)(mdns_answer_t *a, void *arg), void *arg); /** * Returns the first (if last == NULL) or next answer after last from * the cache mdns_answer_t only valid until an I/O function is called */ mdns_answer_t *mdnsd_list(mdns_daemon_t *d, const char *host, int type, mdns_answer_t *last); /** * Returns the next record of the given record, i.e. the value of next field. * @param r the base record * @return r->next */ mdns_record_t *mdnsd_record_next(const mdns_record_t *r); /** * Gets the record data */ const mdns_answer_t *mdnsd_record_data(const mdns_record_t *r); /** * Publishing functions */ /** * Create a new unique record * * Call mdnsd_list() first to make sure the record is not used yet. * * The conflict() callback is called at any point when one is detected * and unable to recover after the first data is set_*(), any future * changes effectively expire the old one and attempt to create a new * unique record */ mdns_record_t *mdnsd_unique(mdns_daemon_t *d, const char *host, unsigned short type, unsigned long ttl, void (*conflict)(char *host, int type, void *arg), void *arg); /** * Create a new shared record */ mdns_record_t *mdnsd_shared(mdns_daemon_t *d, const char *host, unsigned short type, unsigned long ttl); /** * Get a previously created record based on the host name. NULL if not found. Does not return records for other hosts. * If multiple records are found, use record->next to iterate over all the results. */ mdns_record_t *mdnsd_get_published(mdns_daemon_t *d, const char *host); /** * Check if there is already a query for the given host */ int mdnsd_has_query(mdns_daemon_t *d, const char *host); /** * Find previously based record based on name and type */ mdns_record_t *mdnsd_find(mdns_daemon_t *d, const char *name, unsigned short type); /** * de-list the given record */ void mdnsd_done(mdns_daemon_t *d, mdns_record_t *r); /** * These all set/update the data for the given record, nothing is * published until they are called */ void mdnsd_set_raw(mdns_daemon_t *d, mdns_record_t *r, const char *data, unsigned short len); void mdnsd_set_host(mdns_daemon_t *d, mdns_record_t *r, const char *name); void mdnsd_set_ip(mdns_daemon_t *d, mdns_record_t *r, struct in_addr ip); void mdnsd_set_ipv6(mdns_daemon_t *d, mdns_record_t *r, struct in6_addr ip6); void mdnsd_set_srv(mdns_daemon_t *d, mdns_record_t *r, unsigned short priority, unsigned short weight, unsigned short port, char *name); /** * Process input queue and output queue. Should be called at least the time which is returned in nextSleep. * Returns 0 on success, 1 on read error, 2 on write error */ int mdnsd_step(mdns_daemon_t *d, int mdns_socket, bool processIn, bool processOut, struct timeval *tv); /** * Clear all records from the list published * Returns none */ void records_clear(mdns_daemon_t *d); /** * Multi-address support: set all IPv4 addresses for a given host name. * Adds missing A records and removes stale ones. * Returns 0 on success. */ int mdnsd_set_addresses_for_host(mdns_daemon_t *d, const char *host, const struct in_addr *addrs, size_t count); /** * Multi-address support: set all IPv6 addresses for a given host name. * Adds missing AAAA records and removes stale ones. * Returns 0 on success. */ int mdnsd_set_ipv6_addresses_for_host(mdns_daemon_t *d, const char *host, const struct in6_addr *addrs, size_t count); /** * Automatic interface discovery: update all published host A/AAAA records * to match all addresses currently assigned to the given interface. * Returns 0 on success. */ int mdnsd_set_interface_addresses(mdns_daemon_t *d, const char *ifname); #endif /* LIB_MDNSD_H_ */