void OnQuery(object sender, MessageEventArgs e)
{
var request = e.Message;
if (log.IsDebugEnabled)
{
log.Debug($"got query for {request.Questions[0].Name} {request.Questions[0].Type}");
}
var response = NameServer.ResolveAsync(request).Result;
if (response.Status == MessageStatus.NoError)
{
// Many bonjour browsers don't like DNS-SD response
// with additional records.
if (response.Answers.Any(a => a.Name == ServiceName))
{
response.AdditionalRecords.Clear();
}
Mdns.SendAnswer(response);
if (log.IsDebugEnabled)
{
log.Debug($"sent answer {response.Answers[0]}");
}
//Console.WriteLine($"Response time {(DateTime.Now - request.CreationTime).TotalMilliseconds}ms");
}
}
void OnQuery(object sender, MessageEventArgs e)
{
var request = e.Message;
System.Diagnostics.Trace.TraceInformation($"Query from {e.RemoteEndPoint}");
System.Diagnostics.Trace.WriteLine(request);
// Determine if this query is requesting a unicast response
// and normalise the Class.
var QU = false; // unicast query response?
foreach (var r in request.Questions)
{
if (((ushort)r.Class & 0x8000) != 0)
{
QU = true;
r.Class = (DnsClass)((ushort)r.Class & 0x7fff);
}
}
var response = NameServer.ResolveAsync(request).Result;
if (response.Status != MessageStatus.NoError)
{
return;
}
// Many bonjour browsers don't like DNS-SD response
// with additional records.
if (response.Answers.Any(a => a.Name == ServiceName))
{
response.AdditionalRecords.Clear();
}
if (AnswersContainsAdditionalRecords)
{
response.Answers.AddRange(response.AdditionalRecords);
response.AdditionalRecords.Clear();
}
if (!response.Answers.Any(a => a.Name == ServiceName))
{
;
}
if (QU)
{
// TODO: Send a Unicast response if required.
Mdns.SendAnswer(response, e);
}
else
{
Mdns.SendAnswer(response, e);
}
System.Diagnostics.Trace.TraceInformation($"Sending answer");
System.Diagnostics.Trace.WriteLine(response);
//Console.WriteLine($"Response time {(DateTime.Now - request.CreationTime).TotalMilliseconds}ms");
}
void OnQuery(object sender, MessageEventArgs e)
{
var request = e.Message;
_logger.LogDebug($"Query from {e.RemoteEndPoint}");
_logger.LogTrace(request.ToString());
// Determine if this query is requesting a unicast response
// and normalise the Class.
var qu = false; // unicast query response?
foreach (var r in request.Questions)
{
if (((ushort)r.Class & 0x8000) != 0)
{
qu = true;
r.Class = (DnsClass)((ushort)r.Class & 0x7fff);
}
}
var response = NameServer.ResolveAsync(request).Result;
if (response.Status != MessageStatus.NoError)
{
return;
}
// Many bonjour browsers don't like DNS-SD response
// with additional records.
if (response.Answers.Any(a => a.Name == ServiceName))
{
response.AdditionalRecords.Clear();
}
if (AnswersContainsAdditionalRecords)
{
response.Answers.AddRange(response.AdditionalRecords);
response.AdditionalRecords.Clear();
}
if (response.Answers.All(a => a.Name != ServiceName))
{
;
}
if (qu)
{
// TODO: Send a Unicast response if required.
Mdns.SendAnswer(response, e);
}
else
{
Mdns.SendAnswer(response, e);
}
_logger.LogDebug($"Sending answer");
_logger.LogTrace(response.ToString());
}
/// <summary>
/// Creates a new instance of the <see cref="ServiceDiscovery"/> class.
/// </summary>
public ServiceDiscovery()
: this(new MulticastService())
{
ownsMdns = true;
// Auto start.
Mdns.Start();
}
/// <summary>
/// Creates a new instance of the <see cref="ServiceDiscovery"/> class.
/// </summary>
public ServiceDiscovery(ILogger logger)
: this(logger, new MulticastService())
{
_ownsMdns = true;
// Auto start.
Mdns.Start();
}
/// <summary>
/// Asks instances of the specified service with the subtype to send details.
/// </summary>
/// <param name="service">
/// The service name to query. Typically of the form "_<i>service</i>._tcp".
/// </param>
/// <param name="subtype">
/// The feature that is needed.
/// </param>
/// <remarks>
/// When an answer is received the <see cref="ServiceInstanceDiscovered"/> event is raised.
/// </remarks>
/// <seealso cref="ServiceProfile.ServiceName"/>
public void QueryServiceInstances(DomainName service, string subtype)
{
var name = DomainName.Join(
new DomainName(subtype),
SubName,
service,
LocalDomain);
Mdns.SendQuery(name, type: DnsType.PTR);
}
private IPAddress[] resolve()
{
if (llmnr == null)
{
llmnr = new Llmnr();
}
if (mdns == null)
{
mdns = new Mdns();
}
return(NameResolving.ResolveAsync(this.service, 2000, llmnr, mdns).Result);
}
public SshClientWrapper(string service, string IPAddress, ushort port, string username, string password)
{
sshClient = null;
llmnr = null;
mdns = null;
connectThread = null;
enabled = false;
hasConnected = false;
lastDisconnected = DateTime.Now.Subtract(TimeSpan.FromMilliseconds(3000));
this.service = service;
this.IPAddress = IPAddress;
this.port = port;
this.username = username;
this.password = password;
}
/// <inheritdoc />
protected virtual void Dispose(bool disposing)
{
if (disposing)
{
if (Mdns != null)
{
Mdns.QueryReceived -= OnQuery;
Mdns.AnswerReceived -= OnAnswer;
if (ownsMdns)
{
Mdns.Dispose();
}
Mdns = null;
}
}
}
/// <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);
}
/// <summary>
/// Sends a goodbye message for the provided
/// profile and removes its pointer from the name sever.
/// </summary>
/// <param name="profile">The profile to send a goodbye message for.</param>
public void Unadvertise(ServiceProfile profile)
{
var message = new Message {
QR = true
};
var ptrRecord = new PTRRecord {
Name = profile.QualifiedServiceName, DomainName = profile.FullyQualifiedName
};
ptrRecord.TTL = TimeSpan.Zero;
message.Answers.Add(ptrRecord);
profile.Resources.ForEach((resource) =>
{
resource.TTL = TimeSpan.Zero;
message.AdditionalRecords.Add(resource);
});
Mdns.SendAnswer(message);
NameServer.Catalog.TryRemove(profile.QualifiedServiceName, out Node _);
}
/// <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);
});
Mdns.SendAnswer(message, checkDuplicate: false);
Task.Delay(1000).Wait();
Mdns.SendAnswer(message, checkDuplicate: false);
}
void OnQuery(object sender, MessageEventArgs e)
{
// Should run asynchronously because otherwise incoming messages may overlap and it may not be responded to every message.
Task.Run(() =>
{
var request = e.Message;
if (log.IsDebugEnabled)
{
log.Debug($"Query from {e.RemoteEndPoint}");
}
if (log.IsTraceEnabled)
{
log.Trace(request);
}
// Determine if this query is requesting a unicast response
// and normalise the Class.
var QU = false; // unicast query response?
foreach (var r in request.Questions)
{
if (((ushort)r.Class & 0x8000) != 0)
{
QU = true;
r.Class = (DnsClass)((ushort)r.Class & 0x7fff);
}
}
var response = NameServer.ResolveAsync(request).Result;
if (response.Status != MessageStatus.NoError)
{
return;
}
// Many bonjour browsers don't like DNS-SD response
// with additional records.
if (response.Answers.Any(a => a.Name == ServiceName))
{
response.AdditionalRecords.Clear();
}
if (AnswersContainsAdditionalRecords)
{
response.Answers.AddRange(response.AdditionalRecords);
response.AdditionalRecords.Clear();
}
if (!response.Answers.Any(a => a.Name == ServiceName))
{
;
}
// Only return address records that the querier can reach.
response.RemoveUnreachableRecords(e.RemoteEndPoint.Address);
if (QU)
{
// TODO: Send a Unicast response if required.
Mdns.SendAnswer(response, e);
}
else
{
Mdns.SendAnswer(response, e);
}
if (log.IsDebugEnabled)
{
log.Debug($"Sending answer");
}
if (log.IsTraceEnabled)
{
log.Trace(response);
}
}).ConfigureAwait(false);
}
/// <summary>
/// Asks instances of the specified service to send details.
/// </summary>
/// <param name="service">
/// The service name to query. Typically of the form "_<i>service</i>._tcp".
/// </param>
/// <remarks>
/// When an answer is received the <see cref="ServiceInstanceDiscovered"/> event is raised.
/// </remarks>
/// <seealso cref="ServiceProfile.ServiceName"/>
public void QueryServiceInstances(string service)
{
Mdns.SendQuery(service + ".local", type: DnsType.PTR);
}
/// <summary>
/// Asks instances of the specified service to send details.
/// accepts unicast and/or broadcast answers.
/// </summary>
/// <param name="service">
/// The service name to query. Typically of the form "_<i>service</i>._tcp".
/// </param>
/// <remarks>
/// When an answer is received the <see cref="ServiceInstanceDiscovered"/> event is raised.
/// </remarks>
/// <seealso cref="ServiceProfile.ServiceName"/>
public void QueryUnicastServiceInstances(DomainName service)
{
Mdns.SendUnicastQuery(DomainName.Join(service, LocalDomain), type: DnsType.PTR);
}
/// <summary>
/// Asks other MDNS services to send their service names;
/// accepts unicast and/or broadcast answers.
/// </summary>
/// <remarks>
/// When an answer is received the <see cref="ServiceDiscovered"/> event is raised.
/// </remarks>
public void QueryUnicastAllServices()
{
Mdns.SendUnicastQuery(ServiceName, type: DnsType.PTR);
}
/// <summary>
/// Asks other MDNS services to send their service names.
/// </summary>
/// <remarks>
/// When an answer is received the <see cref="ServiceDiscovered"/> event is raised.
/// </remarks>
public void QueryAllServices()
{
Mdns.SendQuery(ServiceName, type: DnsType.PTR);
}
