/// <summary> Add a question to the message.</summary>
internal void AddQuestion(DNSQuestion rec)
{
if (numAnswers > 0 || numAuthorities > 0 || numAdditionals > 0)
{
// TODO is this the right exception?
throw new Exception("Questions must be added before answers");
}
numQuestions++;
WriteQuestion(rec);
}
/// <summary> Add a question to the message.</summary>
internal void AddQuestion(DNSQuestion rec)
{
if (numAnswers > 0 || numAuthorities > 0 || numAdditionals > 0)
{
// TODO is this the right exception?
throw new Exception("Questions must be added before answers");
}
numQuestions++;
WriteQuestion(rec);
}
/// <summary> Add a listener for a question. The listener will receive updates
/// of answers to the question as they arrive, or from the cache if they
/// are already available.
/// </summary>
internal virtual void AddListener(IDNSListener listener, DNSQuestion question)
{
long now = (DateTime.Now.Ticks - 621355968000000000) / 10000;
// add the new listener
lock (this)
{
listeners.Add(listener);
}
// report existing matched records
if (question != null)
{
for (DNSCache.CacheNode i = cache.find(question.name); i != null; i = i.Next)
{
DNSRecord c = (DNSRecord)i.Value;
if (question.IsAnsweredBy(c) && !c.IsExpired(now))
{
listener.UpdateRecord(this, now, c);
}
}
}
}
public virtual void start()
{
// According to draft-cheshire-dnsext-multicastdns.txt
// chapter "8 Responding":
// We respond immediately if we know for sure, that we are
// the only one who can respond to the query.
// In all other cases, we respond within 20-120 ms.
//
// According to draft-cheshire-dnsext-multicastdns.txt
// chapter "7.2 Multi-Packet Known Answer Suppression":
// We respond after 20-120 ms if the query is truncated.
bool iAmTheOnlyOne = true;
foreach (DNSEntry entry in in_Renamed.questions)
{
if (entry is DNSQuestion)
{
DNSQuestion q = (DNSQuestion)entry;
logger.Debug("start() question=" + q);
iAmTheOnlyOne &= (q.type == DNSConstants.TYPE_SRV || q.type == DNSConstants.TYPE_TXT || q.type == DNSConstants.TYPE_A || q.type == DNSConstants.TYPE_AAAA || Enclosing_Instance.localHost.Name.ToUpper().Equals(q.name.ToUpper()) || Enclosing_Instance.services.Contains(q.name.ToLower()));
if (!iAmTheOnlyOne)
{
break;
}
}
}
int delay = (iAmTheOnlyOne && !in_Renamed.Truncated)?0:DNSConstants.RESPONSE_MIN_WAIT_INTERVAL + random.Next(DNSConstants.RESPONSE_MAX_WAIT_INTERVAL - DNSConstants.RESPONSE_MIN_WAIT_INTERVAL + 1) - in_Renamed.ElapsedSinceArrival();
if (delay < 0)
{
delay = 0;
}
logger.Debug("start() Responder chosen delay=" + delay);
// TODO: check this
Enclosing_Instance.Timer = new Timer(new TimerCallback(this.Run), null, delay, 0);
}
public void Run(object state)
{
lock (Enclosing_Instance.IOLock)
{
if (Enclosing_Instance.PlannedAnswer == in_Renamed)
{
Enclosing_Instance.PlannedAnswer = null;
}
// We use these sets to prevent duplicate records
// FIXME - This should be moved into DNSOutgoing
// TODO: check these for compatibility
SupportClass.HashSetSupport questions = new SupportClass.HashSetSupport();
SupportClass.HashSetSupport answers = new SupportClass.HashSetSupport();
if (Enclosing_Instance.State == DNSState.ANNOUNCED)
{
try
{
long now = (DateTime.Now.Ticks - 621355968000000000) / 10000;
long expirationTime = now + 1; //=now+DNSConstants.KNOWN_ANSWER_TTL;
bool isUnicast = (port != DNSConstants.MDNS_PORT);
// Answer questions
foreach (DNSEntry entry in in_Renamed.questions)
{
if (entry is DNSQuestion)
{
DNSQuestion q = (DNSQuestion)entry;
// for unicast responses the question must be included
if (isUnicast)
{
//out.addQuestion(q);
questions.Add(q);
}
int type = q.type;
if (type == DNSConstants.TYPE_ANY || type == DNSConstants.TYPE_SRV)
{
// I ama not sure of why there is a special case here [PJYF Oct 15 2004]
if (Enclosing_Instance.localHost.Name.ToUpper().Equals(q.Name.ToUpper()))
{
// type = DNSConstants.TYPE_A;
DNSRecord answer = Enclosing_Instance.localHost.DNS4AddressRecord;
if (answer != null)
{
answers.Add(answer);
}
answer = Enclosing_Instance.localHost.DNS6AddressRecord;
if (answer != null)
{
answers.Add(answer);
}
type = DNSConstants.TYPE_IGNORE;
}
else if (Enclosing_Instance.serviceTypes.Contains(q.Name.ToLower()))
{
type = DNSConstants.TYPE_PTR;
}
}
switch (type)
{
case DNSConstants.TYPE_A:
{
// Answer a query for a domain name
//out = addAnswer( in, addr, port, out, host );
DNSRecord answer = Enclosing_Instance.localHost.DNS4AddressRecord;
if (answer != null)
{
answers.Add(answer);
}
break;
}
case DNSConstants.TYPE_AAAA:
{
// Answer a query for a domain name
DNSRecord answer = Enclosing_Instance.localHost.DNS6AddressRecord;
if (answer != null)
{
answers.Add(answer);
}
break;
}
case DNSConstants.TYPE_PTR:
{
// Answer a query for services of a given type
// find matching services
foreach (ServiceInfo info in Enclosing_Instance.services.Values)
{
if (info.State == DNSState.ANNOUNCED)
{
if (q.name.ToUpper().Equals(info.type.ToUpper()))
{
DNSRecord answer = Enclosing_Instance.localHost.DNS4AddressRecord;
if (answer != null)
{
answers.Add(answer);
}
answer = Enclosing_Instance.localHost.DNS6AddressRecord;
if (answer != null)
{
answers.Add(answer);
}
answers.Add(new Pointer(info.type, DNSConstants.TYPE_PTR, DNSConstants.CLASS_IN, DNSConstants.DNS_TTL, info.QualifiedName));
answers.Add(new Service(info.QualifiedName, DNSConstants.TYPE_SRV, DNSConstants.CLASS_IN | DNSConstants.CLASS_UNIQUE, DNSConstants.DNS_TTL, info.priority, info.weight, info.port, Enclosing_Instance.localHost.Name));
answers.Add(new Text(info.QualifiedName, DNSConstants.TYPE_TXT, DNSConstants.CLASS_IN | DNSConstants.CLASS_UNIQUE, DNSConstants.DNS_TTL, info.text));
}
}
}
if (q.name.ToUpper().Equals("_services._mdns._udp.local.".ToUpper()))
{
foreach (String s in Enclosing_Instance.serviceTypes.Values)
{
answers.Add(new Pointer("_services._mdns._udp.local.", DNSConstants.TYPE_PTR, DNSConstants.CLASS_IN, DNSConstants.DNS_TTL, s));
}
}
break;
}
case DNSConstants.TYPE_SRV:
case DNSConstants.TYPE_ANY:
case DNSConstants.TYPE_TXT:
{
ServiceInfo info = (ServiceInfo)Enclosing_Instance.services[q.name.ToLower()];
if (info != null && info.State == DNSState.ANNOUNCED)
{
DNSRecord answer = Enclosing_Instance.localHost.DNS4AddressRecord;
if (answer != null)
{
answers.Add(answer);
}
answer = Enclosing_Instance.localHost.DNS6AddressRecord;
if (answer != null)
{
answers.Add(answer);
}
answers.Add(new Pointer(info.type, DNSConstants.TYPE_PTR, DNSConstants.CLASS_IN, DNSConstants.DNS_TTL, info.QualifiedName));
answers.Add(new Service(info.QualifiedName, DNSConstants.TYPE_SRV, DNSConstants.CLASS_IN | DNSConstants.CLASS_UNIQUE, DNSConstants.DNS_TTL, info.priority, info.weight, info.port, Enclosing_Instance.localHost.Name));
answers.Add(new Text(info.QualifiedName, DNSConstants.TYPE_TXT, DNSConstants.CLASS_IN | DNSConstants.CLASS_UNIQUE, DNSConstants.DNS_TTL, info.text));
}
break;
}
default:
{
//Console.WriteLine("JmDNSResponder.unhandled query:"+q);
break;
}
}
}
}
// remove known answers, if the ttl is at least half of
// the correct value. (See Draft Cheshire chapter 7.1.).
foreach (DNSRecord knownAnswer in in_Renamed.answers)
{
bool tempBoolean;
tempBoolean = answers.Contains(knownAnswer);
answers.Remove(knownAnswer);
if (knownAnswer.ttl > DNSConstants.DNS_TTL / 2 && tempBoolean)
{
logger.Debug("JmDNS Responder Known Answer Removed");
}
}
// responde if we have answers
if (answers.Count != 0)
{
logger.Debug("run() JmDNS responding");
DNSOutgoing out_Renamed = null;
if (isUnicast)
{
out_Renamed = new DNSOutgoing(DNSConstants.FLAGS_QR_RESPONSE | DNSConstants.FLAGS_AA, false);
}
foreach (DNSQuestion question in questions)
{
out_Renamed.AddQuestion(question);
}
foreach (DNSRecord answer in answers)
{
out_Renamed = Enclosing_Instance.AddAnswer(in_Renamed, addr, port, out_Renamed, answer);
}
Enclosing_Instance.Send(out_Renamed);
}
// TODO: do we need this?
//cancel();
}
catch (Exception e)
{
logger.Warn("run() exception ", e);
Enclosing_Instance.Close();
}
}
}
}
internal void WriteQuestion(DNSQuestion question)
{
WriteName(question.name);
WriteShort(question.type);
WriteShort(question.clazz);
}
internal void WriteQuestion(DNSQuestion question)
{
WriteName(question.name);
WriteShort(question.type);
WriteShort(question.clazz);
}
/// <summary> Add a listener for a question. The listener will receive updates
/// of answers to the question as they arrive, or from the cache if they
/// are already available.
/// </summary>
internal virtual void AddListener(IDNSListener listener, DNSQuestion question)
{
long now = (DateTime.Now.Ticks - 621355968000000000) / 10000;
// add the new listener
lock (this)
{
listeners.Add(listener);
}
// report existing matched records
if (question != null)
{
for (DNSCache.CacheNode i = cache.find(question.name); i != null; i = i.Next)
{
DNSRecord c = (DNSRecord) i.Value;
if (question.IsAnsweredBy(c) && !c.IsExpired(now))
{
listener.UpdateRecord(this, now, c);
}
}
}
}
/// <summary> Parse a message from a datagram packet.</summary>
internal DNSIncoming(SupportClass.PacketSupport packet)
{
this.packet = packet;
this.data = SupportClass.ToSByteArray(packet.Data);
this.len = packet.Length;
// TODO: will this always be 0 in .NET??
this.off = 0;
this.questions = ArrayList.ReadOnly(new ArrayList());
this.answers = ArrayList.ReadOnly(new ArrayList());
this.receivedTime = (DateTime.Now.Ticks - 621355968000000000) / 10000;
try
{
id = ReadUnsignedShort();
flags = ReadUnsignedShort();
numQuestions = ReadUnsignedShort();
numAnswers = ReadUnsignedShort();
numAuthorities = ReadUnsignedShort();
numAdditionals = ReadUnsignedShort();
// parse questions
if (numQuestions > 0)
{
questions = ArrayList.Synchronized(new ArrayList(numQuestions));
for (int i = 0; i < numQuestions; i++)
{
DNSQuestion question = new DNSQuestion(ReadName(), ReadUnsignedShort(), ReadUnsignedShort());
questions.Add(question);
}
}
// parse answers
int n = numAnswers + numAuthorities + numAdditionals;
if (n > 0)
{
answers = ArrayList.Synchronized(new ArrayList(n));
for (int i = 0; i < n; i++)
{
string domain = ReadName();
int type = ReadUnsignedShort();
int clazz = ReadUnsignedShort();
int ttl = ReadInt();
int len = ReadUnsignedShort();
int end = off + len;
DNSRecord rec = null;
switch (type)
{
case DNSConstants.TYPE_A:
// IPv4
case DNSConstants.TYPE_AAAA: // IPv6 FIXME [PJYF Oct 14 2004] This has not been tested
rec = new Address(domain, type, clazz, ttl, ReadBytes(off, len));
break;
case DNSConstants.TYPE_CNAME:
case DNSConstants.TYPE_PTR:
rec = new Pointer(domain, type, clazz, ttl, ReadName());
break;
case DNSConstants.TYPE_TXT:
rec = new Text(domain, type, clazz, ttl, ReadBytes(off, len));
break;
case DNSConstants.TYPE_SRV:
rec = new Service(domain, type, clazz, ttl, ReadUnsignedShort(), ReadUnsignedShort(), ReadUnsignedShort(), ReadName());
break;
case DNSConstants.TYPE_HINFO:
// Maybe we should do something with those
break;
default:
logger.Debug("DNSIncoming() unknown type:" + type);
break;
}
if (rec != null)
{
// Add a record, if we were able to create one.
answers.Add(rec);
}
else
{
// Addjust the numbers for the skipped record
if (answers.Count < numAnswers)
{
numAnswers--;
}
else if (answers.Count < numAnswers + numAuthorities)
{
numAuthorities--;
}
else if (answers.Count < numAnswers + numAuthorities + numAdditionals)
{
numAdditionals--;
}
}
off = end;
}
}
}
catch (IOException e)
{
logger.Warn("DNSIncoming() dump " + Print(true) + "\n exception ", e);
throw e;
}
}
/// <summary> Parse a message from a datagram packet.</summary>
internal DNSIncoming(SupportClass.PacketSupport packet)
{
this.packet = packet;
this.data = SupportClass.ToSByteArray(packet.Data);
this.len = packet.Length;
// TODO: will this always be 0 in .NET??
this.off = 0;
this.questions = ArrayList.ReadOnly(new ArrayList());
this.answers = ArrayList.ReadOnly(new ArrayList());
this.receivedTime = (DateTime.Now.Ticks - 621355968000000000) / 10000;
try
{
id = ReadUnsignedShort();
flags = ReadUnsignedShort();
numQuestions = ReadUnsignedShort();
numAnswers = ReadUnsignedShort();
numAuthorities = ReadUnsignedShort();
numAdditionals = ReadUnsignedShort();
// parse questions
if (numQuestions > 0)
{
questions = ArrayList.Synchronized(new ArrayList(numQuestions));
for (int i = 0; i < numQuestions; i++)
{
DNSQuestion question = new DNSQuestion(ReadName(), ReadUnsignedShort(), ReadUnsignedShort());
questions.Add(question);
}
}
// parse answers
int n = numAnswers + numAuthorities + numAdditionals;
if (n > 0)
{
answers = ArrayList.Synchronized(new ArrayList(n));
for (int i = 0; i < n; i++)
{
string domain = ReadName();
int type = ReadUnsignedShort();
int clazz = ReadUnsignedShort();
int ttl = ReadInt();
int len = ReadUnsignedShort();
int end = off + len;
DNSRecord rec = null;
switch (type)
{
case DNSConstants.TYPE_A:
// IPv4
case DNSConstants.TYPE_AAAA: // IPv6 FIXME [PJYF Oct 14 2004] This has not been tested
rec = new Address(domain, type, clazz, ttl, ReadBytes(off, len));
break;
case DNSConstants.TYPE_CNAME:
case DNSConstants.TYPE_PTR:
rec = new Pointer(domain, type, clazz, ttl, ReadName());
break;
case DNSConstants.TYPE_TXT:
rec = new Text(domain, type, clazz, ttl, ReadBytes(off, len));
break;
case DNSConstants.TYPE_SRV:
rec = new Service(domain, type, clazz, ttl, ReadUnsignedShort(), ReadUnsignedShort(), ReadUnsignedShort(), ReadName());
break;
case DNSConstants.TYPE_HINFO:
// Maybe we should do something with those
break;
default:
logger.Debug("DNSIncoming() unknown type:" + type);
break;
}
if (rec != null)
{
// Add a record, if we were able to create one.
answers.Add(rec);
}
else
{
// Addjust the numbers for the skipped record
if (answers.Count < numAnswers)
{
numAnswers--;
}
else if (answers.Count < numAnswers + numAuthorities)
{
numAuthorities--;
}
else if (answers.Count < numAnswers + numAuthorities + numAdditionals)
{
numAdditionals--;
}
}
off = end;
}
}
}
catch (IOException e)
{
logger.Warn("DNSIncoming() dump " + Print(true) + "\n exception ", e);
throw e;
}
}
