private void HandlePacketHostAddresses()
{
foreach (var hostAddressKV in _packetHostAddresses)
{
Name name = hostAddressKV.Key;
HostAddresses hostAddresses = hostAddressKV.Value;
HostInfo hostInfo;
_hostInfos.TryGetValue(name, out hostInfo);
if (hostInfo == null)
{
return;
}
List <IPAddress> packetAddresses = new List <IPAddress>();
if (hostAddresses.IPv4Addresses == null)
{
if (hostInfo.Addresses != null)
{
packetAddresses.AddRange(hostInfo.Addresses.Where(a => a.AddressFamily == AddressFamily.InterNetwork));
}
}
else
{
packetAddresses.AddRange(hostAddresses.IPv4Addresses);
}
if (hostAddresses.IPv6Addresses == null)
{
if (hostInfo.Addresses != null)
{
packetAddresses.AddRange(hostInfo.Addresses.Where(a => a.AddressFamily == AddressFamily.InterNetworkV6));
}
}
else
{
packetAddresses.AddRange(hostAddresses.IPv6Addresses);
}
if (packetAddresses.Count == 0)
{
_hostInfos.Remove(name);
foreach (var service in hostInfo.ServiceInfos)
{
PacketRemovesService(service.Name);
}
}
else
{
var addresses = hostInfo.Addresses;
bool same = (addresses != null) && (addresses.Count == packetAddresses.Count) && (addresses.TrueForAll(packetAddresses.Contains));
if (!same)
{
foreach (var service in hostInfo.ServiceInfos)
{
ServiceInfo newService = FindOrCreatePacketService(service.Name);
newService.Addresses = packetAddresses;
}
hostInfo.Addresses = packetAddresses;
}
}
}
}
private void HandlePacketServiceInfos()
{
foreach (var serviceKV in _packetServiceInfos)
{
Name packetName = serviceKV.Key;
ServiceInfo packetService = serviceKV.Value;
if (packetService == null)
{
RemoveService(packetName);
}
else
{
bool modified = false;
bool wasComplete = false;
ServiceInfo service;
_serviceInfos.TryGetValue(packetName, out service);
if (service == null)
{
service = packetService;
_serviceInfos.Add(packetName, service);
_serviceHandlers[packetName.SubName(1)].ServiceInfos.Add(service);
if (service.HostName != null)
{
AddServiceHostInfo(service);
}
modified = true;
}
else
{
service.OpenQueryCount = 0;
wasComplete = service.IsComplete;
if (packetService.Port != -1 && service.Port != packetService.Port)
{
service.Port = packetService.Port;
modified = true;
}
if (packetService.Name.ToString() != service.Name.ToString())
{
service.Name = packetService.Name;
modified = true;
}
if (packetService.Txt != null && (service.Txt == null || !packetService.Txt.SequenceEqual(service.Txt)))
{
service.Txt = packetService.Txt;
modified = true;
}
if (packetService.HostName != null && (service.HostName == null || service.HostName.ToString() != packetService.HostName.ToString()))
{
if (service.HostName != null)
{
ClearServiceHostInfo(service);
}
service.HostName = packetService.HostName;
AddServiceHostInfo(service);
modified = true;
}
if (packetService.Addresses != null)
{
service.Addresses = packetService.Addresses;
modified = true;
}
}
if (modified)
{
if (wasComplete != service.IsComplete)
{
if (wasComplete)
{
ServiceBrowser.OnServiceRemoved(service);
}
else
{
ServiceBrowser.OnServiceAdded(service);
}
}
else if (service.IsComplete)
{
ServiceBrowser.OnServiceChanged(service);
}
}
}
}
}
private void OnReceive(IAsyncResult ar)
#endif
{
lock (this)
{
#if NETSTANDARD1_3
if (args.SocketError != SocketError.Success || _socket == null)
{
return;
}
int length = args.BytesTransferred;
#else
int length;
try
{
if (_socket == null)
{
return;
}
length = _socket.EndReceive(ar);
}
catch (Exception)
{
return;
}
#endif
var stream = new MemoryStream(_buffer, 0, length);
var reader = new DnsMessageReader(stream);
bool validPacket = true;
_packetServiceInfos.Clear();
_packetHostAddresses.Clear();
try
{
Header header = reader.ReadHeader();
if (header.IsQuery && header.AnswerCount == 0)
{
for (int i = 0; i < header.QuestionCount; i++)
{
Question question = reader.ReadQuestion();
Name serviceName = question.QName;
if (_serviceHandlers.ContainsKey(serviceName))
{
if (header.TransactionID != _lastQueryId)
{
OnServiceQuery(serviceName);
}
}
}
}
if (header.IsResponse && header.IsNoError)
{
for (int i = 0; i < header.QuestionCount; i++)
{
reader.ReadQuestion();
}
for (int i = 0; i < (header.AnswerCount + header.AuthorityCount + header.AdditionalCount); i++)
{
RecordHeader recordHeader = reader.ReadRecordHeader();
if ((recordHeader.Type == RecordType.A) || (recordHeader.Type == RecordType.AAAA)) // A or AAAA
{
IPAddress address = reader.ReadARecord();
if (address.AddressFamily == AddressFamily.InterNetworkV6)
{
if (!NetworkInterface.Supports(NetworkInterfaceComponent.IPv6))
{
continue;
}
// Mono does not support IPv6 properties and always throws NotImplementedException.
// Lets handle the case as with Supports.
try
{
address.ScopeId = NetworkInterface.GetIPProperties().GetIPv6Properties().Index;
}
catch (NotImplementedException)
{
continue;
}
}
OnARecord(recordHeader.Name, address, recordHeader.Ttl);
}
else if ((recordHeader.Type == RecordType.SRV) ||
(recordHeader.Type == RecordType.TXT) ||
(recordHeader.Type == RecordType.PTR))
{
Name serviceName;
Name instanceName;
if (recordHeader.Type == RecordType.PTR)
{
serviceName = recordHeader.Name;
instanceName = reader.ReadPtrRecord();
}
else
{
instanceName = recordHeader.Name;
serviceName = instanceName.SubName(1);
}
if (_serviceHandlers.ContainsKey(serviceName))
{
if (recordHeader.Ttl == 0)
{
PacketRemovesService(instanceName);
}
else
{
ServiceInfo service = FindOrCreatePacketService(instanceName);
if (recordHeader.Type == RecordType.SRV)
{
SrvRecord srvRecord = reader.ReadSrvRecord();
service.HostName = srvRecord.Target;
service.Port = srvRecord.Port;
}
else if (recordHeader.Type == RecordType.TXT)
{
List <string> txts = reader.ReadTxtRecord();
service.Txt = txts;
}
}
}
}
}
}
}
catch
{
validPacket = false;
}
if (validPacket)
{
HandlePacketHostAddresses();
HandlePacketServiceInfos();
}
StartReceive();
}
}