NAME

Multicast DNS – mdnsd

SYNOPSIS

#include <mdnsd.h >

int mdnsd_init(struct mdnsd_settings *mdnsd_settings);
void mdnsd_set_hostname(const char *hostname);
struct mdns_service *mdnsd_register_svc(const char *instance_name,
const char *type,
uint16_t port,
const char *txt[]);
struct mdnsd *mdnsd_start(void);
void mdnsd_stop(void);

DESCRIPTION

The multicast Domain Name System (mDNS) is a zero configuration host name resolution service. The mDNS protocol uses IP multicast UDP packets. To provide mDNS features user need to initialize service, setup appropriate host name and supported services, tnen start the daemon thread mdnsd.

User functions

int mdnsd_init(struct mdnsd_settings *mdnsd_settings);
Initialize mDNS service internal structures.

void mdnsd_set_hostname(const char *hostname);
Set the hostname for mdnsd.

struct mdns_service *mdnsd_register_svc(const char *instance_name,
const char *type,
uint16_t port,
const char *txt[]);
Register supported service and begin an announcement.

struct mdnsd *mdnsd_start(void);
Start mDNS service thread.

void mdnsd_stop(void);
Stop mDNS service thread.

EXAMPLE

This is the example how to start and setup mdnsd.

/*
 * Start mdns daemon, set host name and register "_http" and "_print" services
 */
int mDNS_start(void)
{
	int err = 0;
	struct mdnsd_settings mdnsd_settings;

	const char *txt[] = {
		"path=/index.html",
		NULL
	};


	// Fill init parameters
	mdnsd_settings.priority = 5;
	mdnsd_settings.interface = "eth0";

	// Initialize mdns
	err = mdnsd_init(&mdnsd_settings);
	if (err != 0) {
		return -1;
	}

	// Set host name
	mdnsd_set_hostname("Unison-host.local");


	// service register
	mdnsd_register_svc("MyWebsite", "_http._tcp.local", 8080, txt);

	// service register
	mdnsd_register_svc("MyPrinter", "_print._tcp.local", 1111, NULL);


	// Start mdns thread
	err = mdnsd_start();
	if (err != 0) {
		return -1;
	}

	return 0;
}

NOTES

There is a demo available for the Unison and DSPnano mdnsd which is found in installdir/demos.

SEE ALSO

tcpd, autoip