/// <summary>
/// This method will be called periodically on a background thread to handle
/// message resending as well as timeout related state transitions.
/// </summary>
public override void OnBkTask()
{
bool callOnInviteComplete = false;
SipRequest callbackMsg = null;
try
{
using (TimedLock.Lock(agent))
{
if (SysTime.Now >= ttd)
{
SetState(SipTransactionState.Terminated);
return;
}
switch (base.State)
{
default:
case SipTransactionState.Unknown:
break;
case SipTransactionState.InviteCalling:
break;
case SipTransactionState.InviteProceeding:
break;
case SipTransactionState.InviteCompleted:
if (base.TimerH.HasFired)
{
SetState(SipTransactionState.Terminated);
// Setup to call OnInviteComplete(ackRequest=null)
// indicating that the dialog was not established.
callOnInviteComplete = true;
return;
}
if (base.TimerG.HasFired)
{
transport.Send(remoteEP, finalResponse);
base.TimerG.Interval = Helper.Min(base.BaseTimers.T2, Helper.Multiply(base.TimerG.Interval, 2));
}
break;
case SipTransactionState.InviteConfirmed:
if (base.TimerI.HasFired)
{
SetState(SipTransactionState.Terminated);
}
break;
case SipTransactionState.Trying:
break;
case SipTransactionState.Proceeding:
break;
case SipTransactionState.Completed:
if (base.TimerJ.HasFired)
{
SetState(SipTransactionState.Terminated);
}
break;
case SipTransactionState.Terminated:
break;
}
}
}
finally
{
// Handle the agent callbacks outside of the lock to avoid
// deadlock issues.
if (callOnInviteComplete)
{
agent.OnInviteComplete(this, request, finalResponse, callbackMsg);
}
}
}
/// <summary>
/// The managing <see cref="ISipAgent" /> is responsible for calling this
/// method whenever it receives requests correlated to this transaction.
/// </summary>
/// <param name="request">The received <see cref="SipRequest" />.</param>
public void OnRequest(SipRequest request)
{
SipRequest callbackMsg = null;
bool callOnRequest = false;
bool callOnInviteBegin = false;
bool callOnInviteComplete = false;
try
{
request.SourceTransaction = this;
using (TimedLock.Lock(agent))
{
if (this.request == null)
{
SipViaValue viaValue;
SipContactValue toValue;
NetworkBinding sentBy;
IPAddress address;
// This is the initial transaction request.
this.request = request;
// Handle the Via "received" and "rport" header parameters (mostly) as described on page
// RFC 3261 (page 145) and RFC 3581 (page 4).
viaValue = request.GetHeader <SipViaValue>(SipHeader.Via);
if (viaValue == null)
{
// Illegal request
SetState(SipTransactionState.Terminated);
return;
}
sentBy = viaValue.SentByBinding;
if (sentBy == null || sentBy.IsHost || sentBy.Address != request.RemoteEndpoint.Address)
{
viaValue.Received = request.RemoteEndpoint.Address.ToString();
}
if (viaValue.RPort != null)
{
viaValue.RPort = request.RemoteEndpoint.Port.ToString();
}
// Determine the destination network endpoint based on the
// rules described on RFC 3261 (page 146).
if (request.SourceTransport.IsStreaming)
{
// $todo(jeff.lill):
//
// This implementation is incomplete. To be fully
// compliant with the RFC, I'd have to check to
// see if the connection is still present in the
// transport and if not, use the received and
// rport values as described.
remoteEP = request.RemoteEndpoint;
}
else
{
if (viaValue.MAddr != null)
{
if (!IPAddress.TryParse(viaValue.MAddr, out address))
{
SipException e;
// Illegal request
SetState(SipTransactionState.Terminated);
e = new SipException("Illegal request: Invalid [Via: maddr].");
e.Transport = transport.Name;
e.SourceEndpoint = request.RemoteEndpoint;
e.BadMessage = request;
throw e;
}
remoteEP = new NetworkBinding(address, viaValue.SentByBinding.Port);
}
else
{
remoteEP = request.RemoteEndpoint;
}
}
// INVITE and non-INVITE requests have different state machines.
if (request.Method == SipMethod.Invite)
{
// Start an INVITE transaction
SetState(SipTransactionState.InviteProceeding);
// If the request has a "To" header without a "tag" parameter then
// generate a tag. Note that this code will cause provisional INVITE
// responses to include a generated tag which the RFC indicates
// SHOULD NOT be done. But, it's much safer to do this once here
// for all transaction types, avoiding special cases, and besides,
// I've noticed that Asterisk includes a tag in its provisional
// INVITE responses.
toValue = request.GetHeader <SipContactValue>(SipHeader.To);
if (toValue != null)
{
if (toValue["tag"] == null)
{
toValue["tag"] = SipHelper.GenerateTagID();
}
request.SetHeader(SipHeader.To, toValue);
}
// Always send an initial provisional trying response.
provisionalResponse = request.CreateResponse(SipStatus.Trying, null);
SendResponse(provisionalResponse);
// Setup to call the agent's OnInviteBegin() method.
callOnInviteBegin = true;
callbackMsg = request;
}
else if (request.Method == SipMethod.Ack)
{
// Allow an ACK request to drop through to the state machine.
}
else
{
// Start a non-INVITE transaction
SetState(SipTransactionState.Trying);
// Setup to call the agent's OnRequest() method.
callOnRequest = true;
callbackMsg = request;
}
return;
}
// Handle state specific processing
switch (base.State)
{
default:
case SipTransactionState.Unknown:
SysLog.LogError("Unexpected SIP transaction state.");
SetState(SipTransactionState.Terminated);
return;
case SipTransactionState.InviteCalling:
break;
case SipTransactionState.InviteProceeding:
if (provisionalResponse != null)
{
transport.Send(remoteEP, provisionalResponse);
}
break;
case SipTransactionState.InviteCompleted:
if (request.Method == SipMethod.Ack)
{
SetState(SipTransactionState.InviteConfirmed);
// Setup to call OnInviteComplete(ack);
callOnInviteComplete = true;
callbackMsg = request;
return;
}
Assertion.Test(finalResponse != null);
transport.Send(remoteEP, finalResponse);
break;
case SipTransactionState.InviteConfirmed:
break;
case SipTransactionState.Trying:
break;
case SipTransactionState.Proceeding:
Assertion.Test(provisionalResponse != null);
transport.Send(remoteEP, provisionalResponse);
break;
case SipTransactionState.Completed:
Assertion.Test(finalResponse != null);
transport.Send(remoteEP, finalResponse);
break;
case SipTransactionState.Terminated:
break;
}
}
}
finally
{
// Handle the agent callbacks outside of the lock to avoid
// deadlock issues.
if (callOnRequest)
{
agent.OnRequest(this, callbackMsg);
}
if (callOnInviteBegin)
{
agent.OnInviteBegin(this, request);
}
if (callOnInviteComplete)
{
agent.OnInviteComplete(this, this.request, finalResponse, callbackMsg);
}
}
}
/// <summary>
/// Constuctor.
/// </summary>
/// <param name="dialog">The <see cref="SipDialog" />.</param>
/// <param name="transaction">The <see cref="SipTransaction" /> associated with the event (or <c>null</c>).</param>
/// <param name="core">The <see cref="SipCore" /> that raised the event.</param>
/// <param name="clientRequest">Pass the <see cref="SipRequest" /> received for server side dialog creation (or <c>null</c>).</param>
/// <param name="serverResult">The <see cref="SipResult" /> returned by the server, completing its side of the dialog creation (or <c>null</c>).</param>
internal SipDialogEventArgs(SipDialog dialog, SipTransaction transaction, SipCore core, SipRequest clientRequest, SipResult serverResult)
{
this.Dialog = dialog;
this.Transaction = transaction;
this.Core = core;
this.ClientRequest = clientRequest;
this.ServerResult = serverResult;
this.Response = null;
}
/// <summary>
/// Executes a synchronous SIP request transaction.
/// </summary>
/// <param name="request">The <see cref="SipRequest" /> to be submitted.</param>
/// <param name="dialog">The <see cref="SipDialog" /> for requests that initiate a dialog (or <c>null</c>).</param>
/// <returns>The <see cref="SipResult" /> detailing the result of the operation.</returns>
/// <remarks>
/// <note>
/// This method adds reasonable <b>Call-ID</b> and <b>CSeq</b> headers to the request if these
/// headers are not already present.
/// </note>
/// </remarks>
public SipResult Request(SipRequest request, SipDialog dialog)
{
var ar = BeginRequest(request, dialog, null, null);
return(EndRequest(ar));
}
/// <summary>
/// Initiates an asynchronous SIP request transaction.
/// </summary>
/// <param name="request">The <see cref="SipRequest" /> to be submitted.</param>
/// <param name="dialog">The <see cref="SipDialog" /> for requests that initiate a dialog (or <c>null</c>).</param>
/// <param name="callback">The delegate to be called when the operation completes (or <c>null</c>).</param>
/// <param name="state">Application defined state (or <c>null</c>).</param>
/// <returns>The <see cref="IAsyncResult" /> to be used to track the operation's progress.</returns>
/// <remarks>
/// <para>
/// All requests to <see cref="BeginRequest(SipRequest,SipDialog,AsyncCallback,object)" /> must be matched with a
/// call to <see cref="EndRequest" />.
/// </para>
/// <note>
/// This method adds reasonable <b>Call-ID</b> and <b>CSeq</b> headers to the request if these
/// headers are not already present.
/// </note>
/// </remarks>
public IAsyncResult BeginRequest(SipRequest request, SipDialog dialog, AsyncCallback callback, object state)
{
ClientAsyncResult arClient = new ClientAsyncResult(request, dialog, callback, state);
SipValue viaValue;
SipCSeqValue vCSeq;
string transactionID;
SipClientTransaction transaction;
ISipTransport transport;
NetworkBinding remoteEP;
if (dialog != null && request.Method != SipMethod.Invite)
{
throw new InvalidOperationException("Dialogs may be created only for INVITE requests.");
}
arClient.Dialog = dialog;
transport = router.SelectTransport(this, request, out remoteEP);
if (transport == null)
{
throw new SipException("No approriate transport is available.");
}
// Initialize the request's Via header and transaction ID as necessary.
transactionID = SipHelper.GenerateBranchID();
viaValue = new SipValue(string.Format("SIP/2.0/{0} {1}", transport.Name, transport.Settings.ExternalBinding.Address));
viaValue["branch"] = transactionID;
viaValue["rport"] = string.Empty;
request.PrependHeader(SipHeader.Via, viaValue);
// Initialize common headers as necessary
if (!request.ContainsHeader(SipHeader.CallID))
{
request.AddHeader(SipHeader.CallID, SipHelper.GenerateCallID());
}
vCSeq = request.GetHeader <SipCSeqValue>(SipHeader.CSeq);
if (vCSeq == null)
{
vCSeq = new SipCSeqValue(SipHelper.GenCSeq(), request.MethodText);
request.AddHeader(SipHeader.CSeq, vCSeq);
}
// Initialize the transaction
transaction = new SipClientTransaction(this, request, transactionID, transport, remoteEP);
transaction.AgentState = arClient;
// Handle initial dialog INVITE specific initialization
if (dialog != null && request.Method == SipMethod.Invite && dialog.State == SipDialogState.Waiting)
{
// Client-side dialogs need to know the transaction so
// they'll be able to send the confirming ACK.
dialog.InitiatingTransaction = transaction;
// Dialogs need to know about the sequence number used in INVITE requests so
// that the ACK can be generated with the same sequence number.
dialog.AckCSeq = vCSeq.Number;
// The dialog has been intialized enough to be added to the core's
// early dialog table.
core.AddEarlyDialog(dialog);
}
// Start the transaction
using (TimedLock.Lock(this))
{
transactions.Add(transactionID, transaction);
}
transaction.Start();
arClient.Started();
return(arClient);
}
/// <summary>
/// Parses a <see cref="SipRequest" /> or <see cref="SipResponse" /> from the
/// <paramref name="buffer"/> byte array passed.
/// </summary>
/// <param name="buffer">The UTF-8 encoded SIP message data.</param>
/// <param name="isCompletePacket"><c>true</c> if <paramref name="buffer" /> includes both the message header and payload.</param>
/// <returns>A <see cref="SipRequest" /> or <see cref="SipResponse" />.</returns>
/// <remarks>
/// <para>
/// This method is used internally by <see cref="ISipTransport" /> implementations to
/// convert raw data read from the transport into SIP messages. This method supports
/// two basic situations:
/// </para>
/// <list type="bullet">
/// <item>
/// The transport is packet oriented (aka UDP) and the buffer passed includes
/// both the SIP message header and content information. In this case, you
/// need to pass <paramref name="isCompletePacket"/> as <c>true</c>, and the
/// SIP message returned will be complete, with the <see cref="Contents" />
/// property set to the payload bytes.
/// </item>
/// <item>
/// The transport is stream oriented (aka TCP or TLS) and the buffer passed
/// includes only the message header information from the message start line
/// up to and including the empty line terminating the header section. In this
/// case, the <see cref="Contents" /> property of the SIP message returned will
/// be set to <c>null</c> and <see cref="ContentLength" /> will be set to the
/// parsed value. The transport is then responsible for extracting the message
/// payload from the stream and explictly setting the <see cref="Contents" />
/// property.
/// </item>
/// </list>
/// </remarks>
public static SipMessage Parse(byte[] buffer, bool isCompletePacket)
{
string text;
int dataPos;
int p, pEnd, pColon;
string firstLine;
string line;
string reasonPhrase;
string[] fields;
SipMessage message;
SipHeader header;
int cbContents;
dataPos = Helper.IndexOf(buffer, CRLFCRLF);
if (dataPos == -1)
{
throw new SipException("Malformed SIP message: header termination missing.");
}
dataPos += 4;
text = Helper.FromUTF8(buffer, 0, dataPos);
// Look at the first line of text to determine whether we have a
// request or a response.
p = 0;
pEnd = text.IndexOf("\r\n");
firstLine = text.Substring(p, pEnd - p);
fields = firstLine.Split(' ');
if (fields.Length < 3)
{
throw new SipException("Malformed SIP message: invalid first line.");
}
p = firstLine.IndexOf(' ');
p = firstLine.IndexOf(' ', p + 1);
reasonPhrase = firstLine.Substring(p + 1);
if (fields[0].ToUpper().StartsWith("SIP/"))
{
int statusCode;
if (!int.TryParse(fields[1], out statusCode))
{
throw new SipException("Malformed SIP message: invalid response status code.");
}
if (statusCode < 100 || statusCode >= 700)
{
throw new SipException("Invalid status code [{0}].", statusCode);
}
message = new SipResponse(statusCode, reasonPhrase, fields[0]);
}
else
{
message = new SipRequest(fields[0], fields[1], reasonPhrase);
}
// Parse the headers
header = null;
p = pEnd + 2;
while (true)
{
pEnd = text.IndexOf("\r\n", p);
line = text.Substring(p, pEnd - p);
if (line.Length == 0)
{
break;
}
if (line[0] == ' ' || line[0] == '\t')
{
// Header folding
if (header == null)
{
throw new SipException("Malformed SIP message: invalid header folding.");
}
header.FullText += " " + line.Trim();
}
else
{
string name;
string value;
// Parse a normal header: <field-name> ":" <field-value>
pColon = line.IndexOf(':');
if (pColon == -1)
{
throw new SipException("Malformed SIP message: header missing a colon.");
}
name = line.Substring(0, pColon).Trim();
value = line.Substring(pColon + 1).Trim();
header = message.headers.Add(name, value);
}
p = pEnd + 2;
}
// Handle the payload
if (isCompletePacket)
{
// Extract the contents from the buffer. If we have a Content-Length header
// then use that to determine how much data we have, otherwise extract the
// data from the end of the headers to the end of the buffer.
header = message[SipHeader.ContentLength];
if (header != null)
{
if (!int.TryParse(header.Text, out cbContents) || cbContents < 0 || cbContents > buffer.Length - dataPos)
{
throw new SipException("Malformed SIP message: invalid Content-Length.");
}
message.contents = Helper.Extract(buffer, dataPos, cbContents);
}
else
{
message.contents = Helper.Extract(buffer, dataPos);
}
}
else
{
// Messages received from streaming transports must have a valid
// Content-Length header.
header = message[SipHeader.ContentLength];
if (header == null)
{
throw new SipException("Content-Length required for messages received on stream transports.");
}
if (!int.TryParse(header.Text, out cbContents) || cbContents < 0)
{
throw new SipException("Malformed SIP message: invalid Content-Length.");
}
}
return(message);
}
