/// <summary>
/// Analyse the result of the select() call for the specified KAS.
/// </summary>
private void UpdateStateAfterSelect(KcmKas k, SelectSockets selectSockets)
{
try
{
k.CheckNoMessageReceivedInvariant();
// We have nothing to do if we don't have an established TCP
// connection.
if (k.ConnStatus != KcmKasConnectionStatus.Connected &&
k.ConnStatus != KcmKasConnectionStatus.RoleReply) return;
// Perform transfers only if the socket is ready.
Debug.Assert(k.Tunnel.Sock != null);
if (!selectSockets.InReadOrWrite(k.Tunnel.Sock)) return;
// Do up to 20 transfers (the limit exists for quenching purposes).
for (int i = 0; i < 20; i++)
{
// Send a message if possible.
k.SendNextQueuedMsgIfNeeded();
// Remember if we are sending a message.
bool sendingFlag = k.Tunnel.IsSendingMessage();
// Do transfers.
k.Tunnel.DoXfer();
// Stop if no message has been received and no message has been sent.
if (!k.Tunnel.HasReceivedMessage() &&
(!sendingFlag || k.Tunnel.IsSendingMessage())) break;
// Process the message received.
if (k.Tunnel.HasReceivedMessage()) ProcessIncomingKasMessage(k, k.Tunnel.GetMsg());
}
k.CheckNoMessageReceivedInvariant();
}
catch (Exception ex)
{
HandleDisconnectedKas(k, ex);
}
}
/// <summary>
/// Handle a message received from a KAS.
/// </summary>
private void ProcessIncomingKasMessage(KcmKas k, AnpMsg msg)
{
if (k.ConnStatus == KcmKasConnectionStatus.RoleReply)
{
if (msg.Type == KAnpType.KANP_RES_FAIL_MUST_UPGRADE)
throw new Exception("The KWM is too old, it needs to be upgraded to communicate with " +
k.KasID.Host + " which has protocol version " + msg.Minor);
else if (msg.Type != KAnpType.KANP_RES_OK)
throw new Exception(msg.Elements[1].String);
else if (msg.Minor < KAnp.LastCompMinor)
throw new Exception("The KCD at " + k.KasID.Host +
" is too old and needs to be upgraded.");
else HandleConnectedKas(k, Math.Min(msg.Minor, KAnp.Minor));
}
else m_toWmAnpMsgList.Add(new KcmAnpMsg(msg, k.KasID));
}
/// <summary>
/// Mark the KAS as disconnected, add a control message for the KAS in
/// the control message list and add the KAS to the disconnected list.
/// </summary>
private void HandleDisconnectedKas(KcmKas k, Exception ex)
{
if (ex != null) Logging.Log(2, "KAS " + k.KasID.Host + " exception: " + ex.Message);
if (k.Tunnel != null) k.Tunnel.Disconnect();
k.ConnStatus = KcmKasConnectionStatus.Disconnected;
k.Ex = ex;
m_toWmControlMsgList.Add(new KcmDisconnectionNotice(k.KasID, k.Ex));
m_disconnectedList.Add(k);
}
/// <summary>
/// Add the socket of the KAS in the select sets as needed and manage
/// ktlstunnel.exe processes.
/// </summary>
private void PrepareStateForSelect(KcmKas k, SelectSockets selectSockets, bool quenchFlag,
ref bool connWatchFlag)
{
// Note: the KAS should never have received a message when this function
// is called. The function UpdateStateAfterSelect() is responsible for
// doing all the transfers and handling any message received after these
// transfers.
try
{
k.CheckNoMessageReceivedInvariant();
if (k.ConnStatus == KcmKasConnectionStatus.Scheduled)
{
// Start ktlstunnel.exe.
k.ConnStatus = KcmKasConnectionStatus.Connecting;
k.Tunnel.BeginConnect();
}
if (k.ConnStatus == KcmKasConnectionStatus.Connecting)
{
// The TCP connection is now open.
if (k.Tunnel.CheckConnect(0))
{
// Send the select role command.
k.SendSelectRoleMsg();
// Wait for the reply to arrive.
k.ConnStatus = KcmKasConnectionStatus.RoleReply;
}
// Wait for the TCP connection to be established. We busy wait
// to monitor the status of ktlstunnel.exe regularly, to detect
// the case where the connection fails.
else connWatchFlag = true;
}
if (k.ConnStatus == KcmKasConnectionStatus.RoleReply)
{
// Wait for the reply to arrive.
if (!quenchFlag) k.Tunnel.UpdateSelect(selectSockets);
}
if (k.ConnStatus == KcmKasConnectionStatus.Connected)
{
// Send the next message, if possible.
k.SendNextQueuedMsgIfNeeded();
if (!quenchFlag) k.Tunnel.UpdateSelect(selectSockets);
}
k.CheckNoMessageReceivedInvariant();
}
catch (Exception ex)
{
HandleDisconnectedKas(k, ex);
}
}
/// <summary>
/// Mark the KAS as connected and add a control message for the KAS in
/// the control message list.
/// </summary>
private void HandleConnectedKas(KcmKas k, UInt32 minor)
{
k.ConnStatus = KcmKasConnectionStatus.Connected;
m_toWmControlMsgList.Add(new KcmConnectionNotice(k.KasID, minor));
}
