internal TSIP_Transac CreateTransac(Boolean isClient, TSIP_Message message, TSIP_Dialog dialog)
{
TSIP_Transac transac = null;
if (message != null && message.IsRequest)
{
if (isClient)/* Client transaction */
{
if (message.IsINVITE)
{
// INVITE Client transaction (ICT)
TSK_Debug.Error("CreateTransac - not implemented");
}
else
{
// NON-INVITE Client transaction (NICT)
transac = new TSIP_TransacNICT(mReliable, (Int32)message.CSeq.CSeq, message.CSeq.Method, message.CallId.Value, dialog);
}
}
else/* Server transaction */
{
if (message.IsINVITE)
{
// INVITE Server transaction (IST)
TSK_Debug.Error("CreateTransac - not implemented");
}
else
{
// NON-INVITE Server transaction (NIST)
TSK_Debug.Error("CreateTransac - not implemented");
}
if (transac != null)
{
/* Copy branch from the message */
transac.Branch = message.FirstVia.Branch;
}
}
}
mMutex.WaitOne();
if (transac != null)
{
/* Add new transaction */
mTransactions.Add(transac.Id, transac);
}
mMutex.ReleaseMutex();
return(transac);
}
internal TSIP_Transac FindClientTransacByMsg(TSIP_Response response)
{
/* RFC 3261 - 17.1.3 Matching Responses to Client Transactions
*
* When the transport layer in the client receives a response, it has to
* determine which client transaction will handle the response, so that
* the processing of Sections 17.1.1 and 17.1.2 can take place. The
* branch parameter in the top Via header field is used for this
* purpose. A response matches a client transaction under two
* conditions:
*
* 1. If the response has the same value of the branch parameter in
* the top Via header field as the branch parameter in the top
* Via header field of the request that created the transaction.
*
* 2. If the method parameter in the CSeq header field matches the
* method of the request that created the transaction. The
* method is needed since a CANCEL request constitutes a
* different transaction, but shares the same value of the branch
* parameter.
*/
if (response == null || response.FirstVia == null || response.CSeq == null)
{
return(null);
}
TSIP_Transac transac = null;
mMutex.WaitOne();
foreach (TSIP_Transac t in mTransactions.Values)
{
if (String.Equals(t.Branch, response.FirstVia.Branch) && String.Equals(t.CSeqMethod, response.CSeq.Method))
{
transac = t;
break;
}
}
mMutex.ReleaseMutex();
return(transac);
}
internal Boolean HandleIncomingMsg(TSIP_Message message)
{
TSIP_Transac transac = null;
if (message.IsRequest)
{
transac = this.FindServerTransacByMsg(message);
}
else
{
transac = this.FindClientTransacByMsg((message as TSIP_Response));
}
if (transac != null)
{
return(transac.RaiseCallback(TSIP_Transac.tsip_transac_event_type_t.IncomingMessage, message));
}
return(false);
}
internal TSIP_Transac FindServerTransacByMsg(TSIP_Message message)
{
/*
* RFC 3261 - 17.2.3 Matching Requests to Server Transactions
*
* When a request is received from the network by the server, it has to
* be matched to an existing transaction. This is accomplished in the
* following manner.
*
* The branch parameter in the topmost Via header field of the request
* is examined. If it is present and begins with the magic cookie
* "z9hG4bK", the request was generated by a client transaction
* compliant to this specification. Therefore, the branch parameter
* will be unique across all transactions sent by that client. The
* request matches a transaction if:
*
* 1. the branch parameter in the request is equal to the one in the
* top Via header field of the request that created the
* transaction, and
*
* 2. the sent-by value in the top Via of the request is equal to the
* one in the request that created the transaction, and
*
* 3. the method of the request matches the one that created the
* transaction, except for ACK, where the method of the request
* that created the transaction is INVITE.
*/
if (message == null || message.FirstVia == null || message.CSeq == null)
{
return(null);
}
TSIP_Transac transac = null;
mMutex.WaitOne();
foreach (TSIP_Transac t in mTransactions.Values)
{
/* 1. ACK branch won't match INVITE's but they MUST have the same CSeq/CallId values */
if (message.IsACK && String.Equals(t.CallId, message.CallId.Value))
{
if (String.Equals(t.CSeqMethod, TSIP_Request.METHOD_INVITE) && message.CSeq.CSeq == t.CSeqValue)
{
transac = t;
break;
}
}
else if (String.Equals(t.Branch, message.FirstVia.Branch) && (1 == 1))/* FIXME: compare host:ip */
{
if (String.Equals(t.CSeqMethod, message.CSeq.Method))
{
transac = t;
break;
}
else if (message.IsCANCEL || (message.IsResponse && message.CSeq.RequestType == TSIP_Message.tsip_request_type_t.CANCEL))
{
transac = t;
break;
}
}
}
mMutex.ReleaseMutex();
return(transac);
}
