/// <summary>
/// Sends specified request to flow remote end point.
/// </summary>
/// <param name="request">SIP request to send.</param>
/// <exception cref="ObjectDisposedException">Is raised when this object is disposed and this method is accessed.</exception>
/// <exception cref="ArgumentNullException">Is raised when <b>request</b> is null reference.</exception>
public void Send(SIP_Request request)
{
lock (m_pLock){
if (m_IsDisposed)
{
throw new ObjectDisposedException(this.GetType().Name);
}
if (request == null)
{
throw new ArgumentNullException("request");
}
SendInternal(request.ToByteData());
}
}
/// <summary>
/// Processes specified request through this transaction.
/// </summary>
/// <param name="flow">SIP data flow.</param>
/// <param name="request">SIP request.</param>
/// <exception cref="ArgumentNullException">Is raised when <b>flow</b> or <b>request</b> is null reference.</exception>
internal void ProcessRequest(SIP_Flow flow, SIP_Request request)
{
if (flow == null)
{
throw new ArgumentNullException("flow");
}
if (request == null)
{
throw new ArgumentNullException("request");
}
lock (this.SyncRoot){
if (this.State == SIP_TransactionState.Disposed)
{
return;
}
try{
// Log
if (this.Stack.Logger != null)
{
byte[] requestData = request.ToByteData();
this.Stack.Logger.AddRead(
Guid.NewGuid().ToString(),
null,
0,
"Request [transactionID='" + this.ID + "'; method='" + request.RequestLine.Method + "'; cseq='" + request.CSeq.SequenceNumber + "'; " +
"transport='" + flow.Transport + "'; size='" + requestData.Length + "'; received '" + flow.LocalEP + "' <- '" + flow.RemoteEP + "'.",
flow.LocalEP,
flow.RemoteEP,
requestData
);
}
#region INVITE
if (this.Method == SIP_Methods.INVITE)
{
#region INVITE
if (request.RequestLine.Method == SIP_Methods.INVITE)
{
if (this.State == SIP_TransactionState.Proceeding)
{
/* RFC 3261 17.2.1.
* If a request retransmission is received while in the "Proceeding" state, the most recent provisional
* response that was received from the TU MUST be passed to the transport layer for retransmission.
*/
SIP_Response response = this.LastProvisionalResponse;
if (response != null)
{
this.Stack.TransportLayer.SendResponse(this, response);
}
}
else if (this.State == SIP_TransactionState.Completed)
{
/* RFC 3261 17.2.1.
* While in the "Completed" state, if a request retransmission is received, the server SHOULD
* pass the response to the transport for retransmission.
*/
this.Stack.TransportLayer.SendResponse(this, this.FinalResponse);
}
}
#endregion
#region ACK
else if (request.RequestLine.Method == SIP_Methods.ACK)
{
#region Accepeted
if (this.State == SIP_TransactionState.Accpeted)
{
}
#endregion
#region Completed
else if (this.State == SIP_TransactionState.Completed)
{
/* RFC 3261 17.2.1
* If an ACK is received while the server transaction is in the "Completed" state, the server transaction
* MUST transition to the "Confirmed" state. As Timer G is ignored in this state, any retransmissions of the
* response will cease.
*
* When this state is entered, timer I is set to fire in T4 seconds for unreliable transports,
* and zero seconds for reliable transports.
*/
SetState(SIP_TransactionState.Confirmed);
// Stop timers G,H
if (m_pTimerG != null)
{
m_pTimerG.Dispose();
m_pTimerG = null;
// Log
if (this.Stack.Logger != null)
{
this.Stack.Logger.AddText(this.ID, "Transaction [branch='" + this.ID + "';method='" + this.Method + "';IsServer=true] timer G(INVITE response(3xx - 6xx) retransmission) stopped.");
}
}
if (m_pTimerH != null)
{
m_pTimerH.Dispose();
m_pTimerH = null;
// Log
if (this.Stack.Logger != null)
{
this.Stack.Logger.AddText(this.ID, "Transaction [branch='" + this.ID + "';method='" + this.Method + "';IsServer=true] timer H(INVITE ACK wait) stopped.");
}
}
// Start timer I.
m_pTimerI = new TimerEx((flow.IsReliable ? 0 : SIP_TimerConstants.T4), false);
m_pTimerI.Elapsed += new System.Timers.ElapsedEventHandler(m_pTimerI_Elapsed);
// Log
if (this.Stack.Logger != null)
{
this.Stack.Logger.AddText(this.ID, "Transaction [branch='" + this.ID + "';method='" + this.Method + "';IsServer=true] timer I(INVITE ACK retransission wait) started, will trigger after " + m_pTimerI.Interval + ".");
}
m_pTimerI.Enabled = true;
}
#endregion
}
#endregion
}
#endregion
#region Non-INVITE
else
{
// Non-INVITE transaction may have only request retransmission requests.
if (this.Method == request.RequestLine.Method)
{
if (this.State == SIP_TransactionState.Proceeding)
{
/* RFC 3261 17.2.2.
* If a retransmission of the request is received while in the "Proceeding" state, the most
* recently sent provisional response MUST be passed to the transport layer for retransmission.
*/
this.Stack.TransportLayer.SendResponse(this, this.LastProvisionalResponse);
}
else if (this.State == SIP_TransactionState.Completed)
{
/* RFC 3261 17.2.2.
* While in the "Completed" state, the server transaction MUST pass the final response to the transport
* layer for retransmission whenever a retransmission of the request is received.
*/
this.Stack.TransportLayer.SendResponse(this, this.FinalResponse);
}
}
}
#endregion
}
catch (SIP_TransportException x) {
// Log
if (this.Stack.Logger != null)
{
this.Stack.Logger.AddText(this.ID, "Transaction [branch='" + this.ID + "';method='" + this.Method + "';IsServer=true] transport exception: " + x.Message);
}
OnTransportError(x);
}
}
}
/// <summary>
/// Starts sending request.
/// </summary>
/// <exception cref="ObjectDisposedException">Is raised when this object is disposed and and this method is accessed.</exception>
/// <exception cref="InvalidOperationException">Is raised when <b>Start</b> method has alredy called.</exception>
/// <exception cref="SIP_TransportException">Is raised when no transport hop(s) for request.</exception>
public void Start()
{
lock (m_pLock){
if (m_State == SIP_RequestSenderState.Disposed)
{
throw new ObjectDisposedException(this.GetType().Name);
}
if (m_IsStarted)
{
throw new InvalidOperationException("Start method has been already called.");
}
m_IsStarted = true;
m_State = SIP_RequestSenderState.Starting;
// Start may take so, process it on thread pool.
ThreadPool.QueueUserWorkItem(new WaitCallback(delegate(object state){
lock (m_pLock){
if (m_State == SIP_RequestSenderState.Disposed)
{
return;
}
/* RFC 3261 8.1.2 Sending the Request
* The destination for the request is then computed. Unless there is
* local policy specifying otherwise, the destination MUST be determined
* by applying the DNS procedures described in [4] as follows. If the
* first element in the route set indicated a strict router (resulting
* in forming the request as described in Section 12.2.1.1), the
* procedures MUST be applied to the Request-URI of the request.
* Otherwise, the procedures are applied to the first Route header field
* value in the request (if one exists), or to the request's Request-URI
* if there is no Route header field present. These procedures yield an
* ordered set of address, port, and transports to attempt. Independent
* of which URI is used as input to the procedures of [4], if the
* Request-URI specifies a SIPS resource, the UAC MUST follow the
* procedures of [4] as if the input URI were a SIPS URI.
*
* The UAC SHOULD follow the procedures defined in [4] for stateful
* elements, trying each address until a server is contacted. Each try
* constitutes a new transaction, and therefore each carries a different
* topmost Via header field value with a new branch parameter.
* Furthermore, the transport value in the Via header field is set to
* whatever transport was determined for the target server.
*/
// We never use strict, only loose route.
bool isStrictRoute = false;
SIP_Uri uri = null;
if (isStrictRoute)
{
uri = (SIP_Uri)m_pRequest.RequestLine.Uri;
}
else if (m_pRequest.Route.GetTopMostValue() != null)
{
uri = (SIP_Uri)m_pRequest.Route.GetTopMostValue().Address.Uri;
}
else
{
uri = (SIP_Uri)m_pRequest.RequestLine.Uri;
}
try{
// Queue hops.
foreach (SIP_Hop hop in m_pStack.GetHops(uri, m_pRequest.ToByteData().Length, ((SIP_Uri)m_pRequest.RequestLine.Uri).IsSecure))
{
m_pHops.Enqueue(hop);
}
}
catch (Exception x) {
OnTransportError(new SIP_TransportException("SIP hops resolving failed '" + x.Message + "'."));
OnCompleted();
return;
}
if (m_pHops.Count == 0)
{
OnTransportError(new SIP_TransportException("No target hops resolved for '" + uri + "'."));
OnCompleted();
}
else
{
m_State = SIP_RequestSenderState.Started;
try{
if (m_pFlow != null)
{
SendToFlow(m_pFlow, m_pRequest.Copy());
return;
}
}
catch {
// Sending to specified flow failed, probably disposed, just try send to first hop.
}
SendToNextHop();
}
}
}));
}
}