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/*
* SPDX-FileCopyrightText: 2020 Stalwart Labs Ltd <hello@stalw.art>
*
* SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-SEL
*/
use std::time::Instant;
use common::{
config::smtp::session::Stage,
listener::{self, SessionManager, SessionStream},
};
use tokio_rustls::server::TlsStream;
use trc::SmtpEvent;
use crate::{
core::{Session, SessionData, SessionParameters, SmtpSessionManager, State},
queue, reporting,
scripts::ScriptResult,
};
impl SessionManager for SmtpSessionManager {
fn handle<T: SessionStream>(
self,
session: listener::SessionData<T>,
) -> impl std::future::Future<Output = ()> + Send {
// Create session
let mut session = Session {
hostname: String::new(),
core: self.inner.into(),
instance: session.instance,
state: State::default(),
stream: session.stream,
in_flight: vec![session.in_flight],
data: SessionData::new(
session.local_ip,
session.local_port,
session.remote_ip,
session.remote_port,
session.session_id,
),
params: SessionParameters::default(),
};
// Enforce throttle
async {
if session.is_allowed().await
&& session.init_conn().await
&& session.handle_conn().await
&& session.instance.acceptor.is_tls()
{
if let Ok(mut session) = session.into_tls().await {
session.handle_conn().await;
}
}
}
}
#[allow(clippy::manual_async_fn)]
fn shutdown(&self) -> impl std::future::Future<Output = ()> + Send {
async {
let _ = self.inner.inner.queue_tx.send(queue::Event::Stop).await;
let _ = self
.inner
.inner
.report_tx
.send(reporting::Event::Stop)
.await;
let _ = self
.inner
.inner
.ipc
.delivery_tx
.send(common::DeliveryEvent::Stop)
.await;
}
}
}
impl<T: SessionStream> Session<T> {
pub async fn init_conn(&mut self) -> bool {
self.eval_session_params().await;
let config = &self.core.core.smtp.session.connect;
// Sieve filtering
if let Some((script, script_id)) = self
.core
.core
.eval_if::<String, _>(&config.script, self, self.data.session_id)
.await
.and_then(|name| {
self.core
.core
.get_sieve_script(&name, self.data.session_id)
.map(|s| (s, name))
})
{
if let ScriptResult::Reject(message) = self
.run_script(
script_id,
script.clone(),
self.build_script_parameters("connect"),
)
.await
{
let _ = self.write(message.as_bytes()).await;
return false;
}
}
// Milter filtering
if let Err(message) = self.run_milters(Stage::Connect, None).await {
let _ = self.write(message.message.as_bytes()).await;
return false;
}
// MTAHook filtering
if let Err(message) = self.run_mta_hooks(Stage::Connect, None, None).await {
let _ = self.write(message.message.as_bytes()).await;
return false;
}
// Obtain hostname
self.hostname = self
.core
.core
.eval_if::<String, _>(&config.hostname, self, self.data.session_id)
.await
.unwrap_or_default();
if self.hostname.is_empty() {
trc::event!(
Smtp(SmtpEvent::MissingLocalHostname),
SpanId = self.data.session_id,
);
self.hostname = "localhost".to_string();
}
// Obtain greeting
let greeting = self
.core
.core
.eval_if::<String, _>(&config.greeting, self, self.data.session_id)
.await
.filter(|g| !g.is_empty())
.map(|g| format!("220 {}\r\n", g))
.unwrap_or_else(|| "220 Stalwart ESMTP at your service.\r\n".to_string());
if self.write(greeting.as_bytes()).await.is_err() {
return false;
}
true
}
pub async fn handle_conn(&mut self) -> bool {
let mut buf = vec![0; 8192];
let mut shutdown_rx = self.instance.shutdown_rx.clone();
loop {
tokio::select! {
result = tokio::time::timeout(
self.params.timeout,
self.read(&mut buf)) => {
match result {
Ok(Ok(bytes_read)) => {
if bytes_read > 0 {
if Instant::now() < self.data.valid_until && bytes_read <= self.data.bytes_left {
self.data.bytes_left -= bytes_read;
match self.ingest(&buf[..bytes_read]).await {
Ok(true) => (),
Ok(false) => {
return true;
}
Err(_) => {
break;
}
}
} else if bytes_read > self.data.bytes_left {
self
.write(format!("451 4.7.28 {} Session exceeded transfer quota.\r\n", self.hostname).as_bytes())
.await
.ok();
trc::event!(
Smtp(SmtpEvent::TransferLimitExceeded),
SpanId = self.data.session_id,
);
break;
} else {
self
.write(format!("453 4.3.2 {} Session open for too long.\r\n", self.hostname).as_bytes())
.await
.ok();
trc::event!(
Smtp(SmtpEvent::TimeLimitExceeded),
SpanId = self.data.session_id,
);
break;
}
} else {
trc::event!(
Network(trc::NetworkEvent::Closed),
SpanId = self.data.session_id,
CausedBy = trc::location!()
);
break;
}
}
Ok(Err(_)) => {
break;
}
Err(_) => {
trc::event!(
Network(trc::NetworkEvent::Timeout),
SpanId = self.data.session_id,
CausedBy = trc::location!()
);
self
.write(format!("221 2.0.0 {} Disconnecting inactive client.\r\n", self.hostname).as_bytes())
.await
.ok();
break;
}
}
},
_ = shutdown_rx.changed() => {
trc::event!(
Network(trc::NetworkEvent::Closed),
SpanId = self.data.session_id,
Reason = "Server shutting down",
CausedBy = trc::location!()
);
self.write(b"421 4.3.0 Server shutting down.\r\n").await.ok();
break;
}
};
}
false
}
pub async fn into_tls(self) -> Result<Session<TlsStream<T>>, ()> {
Ok(Session {
hostname: self.hostname,
stream: self
.instance
.tls_accept(self.stream, self.data.session_id)
.await?,
state: self.state,
data: self.data,
instance: self.instance,
core: self.core,
in_flight: self.in_flight,
params: self.params,
})
}
}
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