/// <summary>
/// Execute the command handler against the specified session context.
/// </summary>
/// <param name="context">The session context to execute the command handler against.</param>
/// <param name="cancellationToken">The cancellation token.</param>
/// <returns>A task which asynchronously performs the execution.</returns>
async Task ExecuteAsync(SmtpSessionContext context, CancellationToken cancellationToken)
{
// The PROXY protocol requires that the receiver must wait for the
// proxy command to be fully received before it starts processing the
// session. Since the receiver is expected to speak first in SMTP,
// i.e. sending the greeting on connect, we wait for the proxy
// command to be consumed and processed before speaking to the
// remote client.
if (!_context.ServerOptions.Proxy)
{
await OutputGreetingAsync(cancellationToken).ReturnOnAnyThread();
}
if (_context.ServerOptions.Proxy)
{
await IngestProxyAsync(context, cancellationToken).ReturnOnAnyThread();
}
var retries = _context.ServerOptions.MaxRetryCount;
while (retries-- > 0 && context.IsQuitRequested == false && cancellationToken.IsCancellationRequested == false)
{
var text = await ReadCommandInputAsync(context, cancellationToken);
if (text == null)
{
return;
}
if (TryMake(context, text, out var command, out var response))
{
try
{
if (await ExecuteAsync(command, context, cancellationToken).ReturnOnAnyThread())
{
_stateMachine.Transition(context);
}
retries = _context.ServerOptions.MaxRetryCount;
continue;
}
catch (SmtpResponseException responseException)
{
context.IsQuitRequested = responseException.IsQuitRequested;
response = responseException.Response;
}
catch (OperationCanceledException)
{
await context.NetworkClient.ReplyAsync(new SmtpResponse(SmtpReplyCode.ServiceClosingTransmissionChannel, "The session has be cancelled."), cancellationToken);
return;
}
}
await context.NetworkClient.ReplyAsync(CreateErrorResponse(response, retries), cancellationToken);
}
}
/// <summary>
/// Execute the command handler against the specified session context.
/// </summary>
/// <param name="context">The session context to execute the command handler against.</param>
/// <param name="cancellationToken">The cancellation token.</param>
/// <returns>A task which asynchronously performs the execution.</returns>
async Task ExecuteAsync(SmtpSessionContext context, CancellationToken cancellationToken)
{
var retries = _context.ServerOptions.MaxRetryCount;
while (retries-- > 0 && context.IsQuitRequested == false && cancellationToken.IsCancellationRequested == false)
{
var text = await ReadCommandInputAsync(context, cancellationToken).ConfigureAwait(false);
if (text == null)
{
return;
}
if (TryMake(context, text, out var command, out var response) == false)
{
await context.NetworkClient.ReplyAsync(CreateErrorResponse(response, retries), cancellationToken).ConfigureAwait(false);
continue;
}
try
{
if (await ExecuteAsync(command, context, cancellationToken).ConfigureAwait(false))
{
_stateMachine.Transition(context);
}
retries = _context.ServerOptions.MaxRetryCount;
}
catch (SmtpResponseException responseException) when(responseException.IsQuitRequested)
{
await context.NetworkClient.ReplyAsync(responseException.Response, cancellationToken).ConfigureAwait(false);
return;
}
catch (SmtpResponseException responseException)
{
response = CreateErrorResponse(responseException.Response, retries);
await context.NetworkClient.ReplyAsync(response, cancellationToken).ConfigureAwait(false);
}
catch (OperationCanceledException)
{
await context.NetworkClient.ReplyAsync(new SmtpResponse(SmtpReplyCode.ServiceClosingTransmissionChannel, "The session has be cancelled."), cancellationToken).ConfigureAwait(false);
return;
}
}
}
/// <summary>
/// Execute the command handler against the specified session context.
/// </summary>
/// <param name="context">The session context to execute the command handler against.</param>
/// <param name="cancellationToken">The cancellation token.</param>
/// <returns>A task which asynchronously performs the execution.</returns>
async Task ExecuteAsync(SmtpSessionContext context, CancellationToken cancellationToken)
{
var retries = _context.ServerOptions.MaxRetryCount;
while (retries-- > 0 && context.IsQuitRequested == false && cancellationToken.IsCancellationRequested == false)
{
try
{
var command = await ReadCommandAsync(context, cancellationToken).ConfigureAwait(false);
if (command == null)
{
return;
}
if (_stateMachine.TryAccept(command, out var errorResponse) == false)
{
throw new SmtpResponseException(errorResponse);
}
if (await ExecuteAsync(command, context, cancellationToken).ConfigureAwait(false))
{
_stateMachine.Transition(context);
}
retries = _context.ServerOptions.MaxRetryCount;
}
catch (SmtpResponseException responseException) when(responseException.IsQuitRequested)
{
await context.Pipe.Output.WriteReplyAsync(responseException.Response, cancellationToken).ConfigureAwait(false);
context.IsQuitRequested = true;
}
catch (SmtpResponseException responseException)
{
var response = CreateErrorResponse(responseException.Response, retries);
await context.Pipe.Output.WriteReplyAsync(response, cancellationToken).ConfigureAwait(false);
}
catch (OperationCanceledException)
{
await context.Pipe.Output.WriteReplyAsync(new SmtpResponse(SmtpReplyCode.ServiceClosingTransmissionChannel, "The session has be cancelled."), CancellationToken.None).ConfigureAwait(false);
}
}
}