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#[cfg(feature = "driver")]
use crate::common::io::*;
use crate::common::*;
use crate::io::tls::MayBeTls;
use crate::smtp::*;
pub trait Drive: fmt::Debug {
fn drive<'a, 'i, 'x, 's, 'f>(
&'a self,
io: &'i mut Box<dyn MayBeTls>,
interpretter: &'x (dyn Interpret + Send + Sync),
state: &'s mut SmtpContext,
) -> S1Fut<'f, std::result::Result<(), DriverError>>
where
'a: 'f,
'i: 'f,
'x: 'f,
's: 'f;
}
#[cfg(feature = "driver")]
#[derive(Debug)]
pub struct SmtpDriver;
#[cfg(feature = "driver")]
impl Drive for SmtpDriver {
fn drive<'a, 'i, 'x, 's, 'f>(
&'a self,
bare_io: &'i mut Box<dyn MayBeTls>,
interpretter: &'x (dyn Interpret + Send + Sync),
state: &'s mut SmtpContext,
) -> S1Fut<'f, std::result::Result<(), DriverError>>
where
'a: 'f,
'i: 'f,
'x: 'f,
's: 'f,
{
Box::pin(async move {
state.service().prepare_session(bare_io, state).await;
let mut io = async_std::io::BufReader::new(bare_io);
// fetch and apply commands
loop {
// write all pending responses
while let Some(response) = state.session.pop_control() {
trace!("Processing driver control {:?}", response);
use async_std::io::prelude::WriteExt;
match response {
DriverControl::Response(bytes) => {
let writer = io.get_mut();
let write = writer
.write_all(bytes.as_ref())
.await
.map_err(DriverError::WriteFailed);
let flush = writer.flush().await.map_err(DriverError::WriteFailed);
match write.and(flush) {
Ok(()) => {}
Err(e) => {
return Err(e);
}
}
}
DriverControl::Shutdown => {
state.session.input.extend_from_slice(io.buffer());
// TODO: replace with close() after https://github.com/async-rs/async-std/issues/977
match poll_fn(move |cx| Pin::new(io.get_mut()).poll_close(cx)).await {
Ok(()) => {
trace!("Shutdown completed");
return Ok(());
}
Err(e) => {
return Err(DriverError::CloseFailed(e));
}
}
}
DriverControl::StartTls => {
Pin::new(io.get_mut()).encrypt();
}
}
}
match interpretter.interpret(state).await {
Ok(None) => {
// Action taken, but no input consumed (i.e. session setup / shut down)
}
Ok(Some(consumed)) => {
assert_ne!(consumed, 0, "If consumed is 0, infinite loop is likely.");
assert!(
consumed <= state.session.input.len(),
"The interpreter consumed more than a buffer? How?"
);
// TODO: handle buffer more efficiently, now allocating all the time
state.session.input = state.session.input.split_off(consumed);
}
Err(ParseError::Incomplete) => {
use async_std::io::prelude::BufReadExt;
// TODO: take care of large chunks without LF
match io.read_until(b'\n', &mut state.session.input).await {
Err(e) if e.kind() == std::io::ErrorKind::TimedOut => {
warn!("session read timeout");
state.session.say_shutdown_timeout();
}
Err(e) => return Err(e.into()),
Ok(0) => {
if state.session.input.is_empty() {
// client went silent, we're done!
state.session.shutdown();
} else {
error!(
"Incomplete and finished: {:?}",
String::from_utf8_lossy(state.session.input.as_slice())
);
// client did not finish the command and left.
state
.session
.say_shutdown_processing_err("Incomplete command".into());
};
}
Ok(_) => { /* good, interpret again */ }
}
}
Err(e) => {
warn!(
"Invalid command {:?} - {}",
String::from_utf8_lossy(state.session.input.as_slice()),
e
);
// remove one line from the buffer
let split = state
.session
.input
.iter()
.position(|b| *b == b'\n')
.map(|p| p + 1)
.unwrap_or(state.session.input.len());
state.session.input = state.session.input.split_off(split);
if split == 0 {
warn!("Parsing failed on empty input, this will fail again, stopping the session");
state.session.say_shutdown_service_err()
} else {
state.session.say_invalid_syntax();
}
}
};
}
})
}
}
#[derive(Debug)]
pub enum DriverError {
IoClosed,
WriteFailed(io::Error),
CloseFailed(io::Error),
ParsingFailed(io::Error),
IoFailed(io::Error),
}
impl fmt::Display for DriverError {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "{:?}", self)
}
}
impl std::error::Error for DriverError {}
impl From<std::io::Error> for DriverError {
fn from(e: std::io::Error) -> Self {
DriverError::IoFailed(e)
}
}