/// <summary>
/// Invoked when an IQ stanza has been received.
/// </summary>
/// <param name="stanza">The stanza which has been received.</param>
/// <returns>true to intercept the stanza or false to pass the stanza
/// on to the next handler.</returns>
public async Task <bool> Input(Iq stanza)
{
if (stanza.Type != IqType.Set)
{
return(false);
}
var e = stanza.Data["open"];
if (e == null)
{
e = stanza.Data["close"];
}
if (e == null)
{
e = stanza.Data["data"];
}
if (e == null || e.NamespaceURI != "http://jabber.org/protocol/ibb")
{
return(false);
}
string sessionId = e.GetAttribute("sid");
// Dispatch to the proper handler method.
try
{
switch (e.Name)
{
case "open":
Open(sessionId, stanza);
break;
case "data":
await Data(sessionId, stanza);
break;
case "close":
Close(sessionId, stanza);
break;
default:
throw new ArgumentException("Invalid stanza element.");
}
// Acknowledge the IQ request.
await im.IqResult(stanza);
}
catch (Exception ex)
{
// Send an error response.
await im.IqError(stanza, ErrorType.Cancel, ErrorCondition.ServiceUnavailable,
ex.Message);
// If there is an open stream associated with the session id, we should
// dispose of it.
siFileTransfer.InvalidateSession(sessionId);
}
// We took care of this IQ request, so intercept it and don't pass it
// on to other handlers.
return(true);
}
/// <summary>
/// Performs the actual data-transfer implied by the specified
/// SI session.
/// </summary>
/// <param name="session">The SI session whose data to transfer.</param>
/// <exception cref="ArgumentNullException">The session parameter is
/// null.</exception>
/// <exception cref="NotSupportedException">The XMPP extension
/// implementing this method is not supported by the intended recipient's
/// XMPP client.</exception>
/// <exception cref="XmppErrorException">The server or the XMPP entity
/// with the specified JID returned an XMPP error code. Use the Error
/// property of the XmppErrorException to obtain the specific error
/// condition.</exception>
/// <exception cref="XmppException">The server returned invalid data or
/// another unspecified XMPP error occurred.</exception>
public void Transfer(SISession session)
{
IEnumerable <Streamhost> proxies = null;
// Determine if this is going to be a direct or a mediated transfer.
if (ProxyAllowed)
{
try
{
var externalAddresses = GetExternalAddresses();
// If all of our external addresses are behind NATs, we may need a proxy.
bool behindNAT = externalAddresses.All(addr => BehindNAT(addr));
if (behindNAT)
{
// Look for user-defined proxies first.
if (Proxies.Count > 0)
{
proxies = Proxies;
}
else
{
// Otherwise query XMPP server for a list of proxies.
proxies = GetProxyList();
}
}
}
catch
{
// Retrieving the external addresses may fail as well as querying
// the XMPP server for proxies. In these cases, we at least try
// with a direct transfer.
}
}
try
{
if (proxies != null && proxies.Count() > 0)
{
MediatedTransfer(session, proxies);
}
else
{
DirectTransfer(session);
}
}
catch (Exception)
{
// Raise the 'TransferAborted' event.
TransferAborted.Raise(this, new TransferAbortedEventArgs(session));
// Invalidate the session.
siFileTransfer.InvalidateSession(session.Sid);
}
}