/// <summary>
/// Creates a new instance of the <see cref="ServiceProfile"/> class
/// with the specified details.
/// </summary>
/// <param name="instanceName">
/// A unique identifier for the specific service instance.
/// </param>
/// <param name="serviceName">
/// The <see cref="ServiceName">name</see> of the service.
/// </param>
/// <param name="port">
/// The TCP/UDP port of the service.
/// </param>
/// <param name="addresses">
/// The IP addresses of the specific service instance. If <b>null</b> then
/// <see cref="MulticastService.GetIpAddresses"/> is used.
/// </param>
/// <remarks>
/// The SRV, TXT and A/AAAA resoruce records are added to the <see cref="Resources"/>.
/// </remarks>
public ServiceProfile(DomainName instanceName, DomainName serviceName, ushort port, IEnumerable <IPAddress> addresses = null)
{
InstanceName = instanceName;
ServiceName = serviceName;
var fqn = FullyQualifiedName;
var simpleServiceName = new DomainName(ServiceName.ToString()
.Replace("._tcp", "")
.Replace("._udp", "")
.Trim('_')
.Replace("_", "-"));
HostName = DomainName.Join(InstanceName, serviceName, Domain);
Resources.Add(new SRVRecord
{
Name = fqn,
Port = port,
Target = HostName
});
foreach (var address in addresses ?? MulticastService.GetLinkLocalAddresses())
{
Resources.Add(AddressRecord.Create(HostName, address));
}
}
/// <summary>
/// Sends an unsolicited MDNS response describing the
/// service profile.
/// </summary>
/// <param name="profile">
/// The profile to describe.
/// </param>
/// <remarks>
/// Sends a MDNS response <see cref="Message"/> containing the pointer
/// and resource records of the <paramref name="profile"/>.
/// <para>
/// To provide increased robustness against packet loss,
/// two unsolicited responses are sent one second apart.
/// </para>
/// </remarks>
public void Announce(ServiceProfile profile)
{
var message = new Message {
QR = true
};
// Add the shared records.
var ptrRecord = new PTRRecord {
Name = profile.QualifiedServiceName, DomainName = profile.FullyQualifiedName
};
message.Answers.Add(ptrRecord);
// Add the resource records.
profile.Resources.ForEach((resource) =>
{
message.Answers.Add(resource);
});
message.Questions.Add(new Question()
{
Name = profile.ServiceName,
Class = DnsClass.IN,
Type = DnsType.PTR
});
foreach (var ip in MulticastService.GetLinkLocalAddresses())
{
message.AdditionalRecords.Add(new ARecord()
{
Class = DnsClass.IN,
Type = DnsType.A,
Name = profile.ServiceName,
Address = ip,
TTL = TimeSpan.FromSeconds(120)
});
}
Mdns.Send(message, false);
Task.Delay(1000).Wait();
Mdns.Send(message, false);
}
