public async Task <FtpStreamChannel> OpenPassiveDataStreamAsync(FtpDataConnectionType connectionType, FtpRequest request)
{
FtpPassiveModeResponse reply;
if (connectionType == FtpDataConnectionType.EPSV || connectionType == FtpDataConnectionType.AutoPassive)
{
if (!(reply = await SetExtendedPassiveMode()).Success)
{
// if we're connected with IPv4 and data channel type is AutoPassive then fallback to IPv4
if (reply.Type == FtpResponseType.PermanentNegativeCompletion && connectionType == FtpDataConnectionType.AutoPassive && LocalEndPoint.Type == HostNameType.Ipv4)
{
return(await OpenPassiveDataStreamAsync(FtpDataConnectionType.PASV, request));
}
throw new FtpCommandException(reply);
}
}
else
{
if (LocalEndPoint.Type != HostNameType.Ipv4)
{
throw new FtpException("Only IPv4 is supported by the PASV command. Use EPSV instead.");
}
if (!(reply = await SetPassiveMode()).Success)
{
throw new FtpCommandException(reply);
}
}
var passiveConnection = new FtpStreamChannel();
await passiveConnection.ConnectAsync(reply.HostName, reply.ServiceName);
// NOTE: Maybe it is better to just to open the passive channel, and execute the command else where..
if (!(await ExecuteAsync <FtpResponse>(request)).Success)
{
passiveConnection.Dispose();
throw new FtpCommandException(reply);
}
return(passiveConnection);
}
/// <summary>
/// Connect to the server
/// </summary>
public async Task ConnectAsync()
{
if (m_Stream == null)
{
m_Stream = new FtpStreamChannel();
}
else
{
if (IsConnected)
{
await DisconnectAsync();
}
}
if (HostName == null)
{
throw new FtpException("No host has been specified");
}
if (Credentials == null)
{
throw new FtpException("No credentials have been specified");
}
FtpResponse reply;
if (await m_Stream.ConnectAsync(HostName, ServiceName))
{
if (!(reply = await GetReplyAsync()).Success)
{
if (reply.Code == null)
{
throw new IOException("The connection was terminated before a greeting could be read.");
}
throw new FtpCommandException(reply);
}
}
// TODO: If the encryption mode is set to explicit, raise to SSL
if (Credentials != null)
{
await AuthenticateAsync(Credentials);
}
if ((reply = await m_Stream.GetFeaturesAsync()).Success)
{
m_Caps = ((FtpFeaturesResponse)reply).Features;
}
// Enable UTF8 if it's available
if (m_Caps.HasFlag(FtpCapability.UTF8))
{
// If the server supports UTF8 it should already be enabled and this
// command should not matter however there are conflicting drafts
// about this so we'll just execute it to be safe.
await m_Stream.SetOptionsAsync("UTF8 ON");
m_Stream.Encoding = Encoding.UTF8;
}
}
