private async Task <IntPtr> DialAsync(VpnData vpnData, CancellationToken cancellationToken)
{
Log.Information($"VPN dialing");
TaskCompletionSource <bool> tcs = new TaskCompletionSource <bool>();
var handle = VpnApi.Dial(EntryName, vpnData.User, vpnData.Pwd,
(message, state, errorCode, extendedErrorCode) =>
{
Log.Information($"VPN dialing {state} ({VpnApi.RasErrorMessage(errorCode)}, {message}, {extendedErrorCode})");
if (state == RasConnectionState.Connected)
{
tcs.TrySetResult(true);
}
else
{
if (errorCode != 0)
{
tcs.TrySetException(new VpnException($"VPN setup failed ({VpnApi.RasErrorMessage(errorCode)})"));
}
}
});
try
{
var timeout = Task.Delay(10000, cancellationToken);
var res = await Task.WhenAny(timeout, tcs.Task);
if (res == timeout)
{
throw new VpnException("Timeout during VPN setup");
}
return(handle);
}
catch
{
await HangUpAsync(handle);
throw;
}
}
private async Task MaintainConnection(VpnData vpnData, CancellationToken cancellationToken, TaskCompletionSource <bool> firstTime, Action <VpnRuntimeState> onStateChanged)
{
Task awaitConnectionChanged = null;
IntPtr handle = IntPtr.Zero;
bool statInitialized = false;
RAS_STATS prevStat = new RAS_STATS();
string serverIpAddress = null;
try
{
while (!_cts.IsCancellationRequested)
{
try
{
if (handle == IntPtr.Zero)
{
Log.Information("VPN Connecting");
handle = await ReconnectAsync(vpnData, _cts.Token);
var info = VpnApi.GetProjectionInfoEx(handle);
serverIpAddress = $"{info.ipv4ServerAddress.addr[0]}.{info.ipv4ServerAddress.addr[1]}.{info.ipv4ServerAddress.addr[2]}.{info.ipv4ServerAddress.addr[3]}";
firstTime?.TrySetResult(true);
firstTime = null;
statInitialized = false;
var eventHandle = VpnApi.RegisterForTermination(handle);
awaitConnectionChanged = TaskHelper.WaitOneAsync(eventHandle, "VPN state changed");
}
if (handle != IntPtr.Zero)
{
var status = VpnApi.GetState(handle);
var stat = VpnApi.GetStatisitcs(handle);
if (status.connectionState != RasConnectionState.Connected)
{
if (status.errorCode == 0)
{
throw new VpnException($"VPN in wrong '{status.connectionState}' state");
}
else
{
throw new VpnException($"VPN error '{VpnApi.RasErrorMessage(status.errorCode)}'");
}
}
if (!statInitialized)
{
statInitialized = true;
prevStat = stat;
}
var delta = GetStatDelta(stat, prevStat);
prevStat = stat;
if (delta.dwTimeoutErr + delta.dwFramingErr + delta.dwCrcErr + delta.dwHardwareOverrunErr + delta.dwBufferOverrunErr + delta.dwAlignmentErr > 0)
{
Log.Warning($"VPN errors {delta.dwTimeoutErr},{delta.dwFramingErr},{delta.dwCrcErr},{delta.dwHardwareOverrunErr},{delta.dwBufferOverrunErr},{delta.dwAlignmentErr}");
}
onStateChanged(new VpnRuntimeState
{
Connected = true,
SentKbs = (int)delta.dwBytesXmited / (1024 / 8),
ReceivedKbs = (int)delta.dwBytesRcved / (1024 / 8),
ServerIpAddress = serverIpAddress
});
}
}
catch (Exception e) when(TaskHelper.IsCancellation(e))
{
Log.Error(e, "VPN cancellation");
throw;
}
catch (Exception e)
{
Log.Error(e, "VPN maintanance error");
firstTime?.TrySetException(e);
firstTime = null;
serverIpAddress = null;
onStateChanged(new VpnRuntimeState {
Connected = false, ErrorMessage = e.Message
});
await HangUpAsync(handle);
handle = IntPtr.Zero;
awaitConnectionChanged = null;
}
var delay = Task.Delay(1000, cancellationToken);
if (awaitConnectionChanged != null)
{
var result = await Task.WhenAny(delay, awaitConnectionChanged);
if (result == awaitConnectionChanged)
{
Log.Information("VPN short wait");
awaitConnectionChanged = null; //it is raised once and not usable anymore
}
}
else
{
await delay;
}
}
}
finally
{
Log.Information("VPN exiting maintainance");
await HangUpAsync(handle);
onStateChanged(new VpnRuntimeState {
Connected = false
});
_disconnected?.TrySetResult(true);
}
}