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authorQuentin Dufour <quentin@deuxfleurs.fr>2022-06-17 18:39:36 +0200
committerQuentin Dufour <quentin@deuxfleurs.fr>2022-06-17 18:39:36 +0200
commit5dd5ae8bcd6f88703bc483d7f8d5882fefad4e7e (patch)
tree312708a97fcfcd273481f41b8bd6c878030573f4 /src/imap/session.rs
parent41f1b02171cee36706d30cf24329ff12780d47fd (diff)
downloadaerogramme-5dd5ae8bcd6f88703bc483d7f8d5882fefad4e7e.tar.gz
aerogramme-5dd5ae8bcd6f88703bc483d7f8d5882fefad4e7e.zip
WIP Refactor, code is broken
Diffstat (limited to 'src/imap/session.rs')
-rw-r--r--src/imap/session.rs201
1 files changed, 201 insertions, 0 deletions
diff --git a/src/imap/session.rs b/src/imap/session.rs
new file mode 100644
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--- /dev/null
+++ b/src/imap/session.rs
@@ -0,0 +1,201 @@
+use std::sync::Arc;
+
+use anyhow::Error;
+use boitalettres::errors::Error as BalError;
+use boitalettres::proto::{Request, Response};
+use futures::future::BoxFuture;
+use futures::future::FutureExt;
+use imap_codec::types::command::CommandBody;
+use imap_codec::types::response::{Capability, Code, Data, Response as ImapRes, Status};
+use tokio::sync::mpsc::error::TrySendError;
+use tokio::sync::{mpsc, oneshot};
+
+use crate::command::{anonymous,authenticated,selected};
+use crate::login::Credentials;
+use crate::mailbox::Mailbox;
+use crate::LoginProvider;
+
+/* This constant configures backpressure in the system,
+ * or more specifically, how many pipelined messages are allowed
+ * before refusing them
+ */
+const MAX_PIPELINED_COMMANDS: usize = 10;
+
+struct Message {
+ req: Request,
+ tx: oneshot::Sender<Result<Response, BalError>>,
+}
+
+//-----
+
+pub struct Manager {
+ tx: mpsc::Sender<Message>,
+}
+
+impl Manager {
+ pub fn new(login_provider: ArcLoginProvider) -> Self {
+ let (tx, rx) = mpsc::channel(MAX_PIPELINED_COMMANDS);
+ tokio::spawn(async move {
+ let mut instance = Instance::new(login_provider, rx);
+ instance.start().await;
+ });
+ Self { tx }
+ }
+
+ pub fn process(&self, req: Request) -> BoxFuture<'static, Result<Response, BalError>> {
+ let (tx, rx) = oneshot::channel();
+ let tag = req.tag.clone();
+ let msg = Message { req, tx };
+
+ // We use try_send on a bounded channel to protect the daemons from DoS.
+ // Pipelining requests in IMAP are a special case: they should not occure often
+ // and in a limited number (like 3 requests). Someone filling the channel
+ // will probably be malicious so we "rate limit" them.
+ match self.tx.try_send(msg) {
+ Ok(()) => (),
+ Err(TrySendError::Full(_)) => {
+ return async {
+ Status::bad(Some(tag), None, "Too fast! Send less pipelined requests!")
+ .map(|s| vec![ImapRes::Status(s)])
+ .map_err(|e| BalError::Text(e.to_string()))
+ }
+ .boxed()
+ }
+ Err(TrySendError::Closed(_)) => {
+ return async {
+ Status::bad(Some(tag), None, "The session task has exited")
+ .map(|s| vec![ImapRes::Status(s)])
+ .map_err(|e| BalError::Text(e.to_string()))
+ }
+ .boxed()
+ }
+ };
+
+ // @FIXME add a timeout, handle a session that fails.
+ async {
+ match rx.await {
+ Ok(r) => r,
+ Err(e) => {
+ tracing::warn!("Got error {:#?}", e);
+ Status::bad(Some(tag), None, "No response from the session handler")
+ .map(|s| vec![ImapRes::Status(s)])
+ .map_err(|e| BalError::Text(e.to_string()))
+ }
+ }
+ }
+ .boxed()
+ }
+}
+
+//-----
+
+pub struct Context<'a> {
+ req: &'a Request,
+ state: &'a mut flow::State,
+ login: ArcLoginProvider,
+}
+
+pub struct Instance {
+ rx: mpsc::Receiver<Message>,
+
+ pub login_provider: ArcLoginProvider,
+ pub state: flow::State,
+}
+impl Instance {
+ fn new(
+ login_provider: ArcLoginProvider,
+ rx: mpsc::Receiver<Message>,
+ ) -> Self {
+ Self {
+ login_provider,
+ rx,
+ state: flow::State::NotAuthenticated,
+ }
+ }
+
+ //@FIXME add a function that compute the runner's name from its local info
+ // to ease debug
+ // fn name(&self) -> String { }
+
+ async fn start(&mut self) {
+ //@FIXME add more info about the runner
+ tracing::debug!("starting runner");
+
+ while let Some(msg) = self.rx.recv().await {
+ let ctx = Context { req: &msg.req, state: &mut self.state, login: self.login_provider };
+
+ // Command behavior is modulated by the state.
+ // To prevent state error, we handle the same command in separate code path depending
+ // on the State.
+ let cmd_res = match self.state {
+ flow::State::NotAuthenticated => anonymous::dispatch(ctx).await,
+ flow::State::Authenticated(user) => authenticated::dispatch(ctx).await,
+ flow::State::Selected(user, mailbox) => selected::dispatch(ctx).await,
+ flow::State::Logout => Status::bad(Some(ctx.req.tag.clone()), None, "No commands are allowed in the LOGOUT state.")
+ .map(|s| vec![ImapRes::Status(s)])
+ .map_err(Error::msg),
+ };
+
+/*
+
+ match req.body {
+ CommandBody::Capability => anonymous::capability().await,
+ CommandBody::Login { username, password } => anonymous::login(self.login_provider, username, password).await.and_then(|(user, response)| {
+ self.state.authenticate(user)?;
+ Ok(response)
+ },
+ _ => Status::no(Some(msg.req.tag.clone()), None, "This command is not available in the ANONYMOUS state.")
+ .map(|s| vec![ImapRes::Status(s)])
+ .map_err(Error::msg),
+
+ },
+ flow::State::Authenticated(user) => match req.body {
+ CommandBody::Capability => anonymous::capability().await, // we use the same implem for now
+ CommandBody::Lsub { reference, mailbox_wildcard, } => authenticated::lsub(reference, mailbox_wildcard).await,
+ CommandBody::List { reference, mailbox_wildcard, } => authenticated::list(reference, mailbox_wildcard).await,
+ CommandBody::Select { mailbox } => authenticated::select(user, mailbox).await.and_then(|(mailbox, response)| {
+ self.state.select(mailbox);
+ Ok(response)
+ }),
+ _ => Status::no(Some(msg.req.tag.clone()), None, "This command is not available in the AUTHENTICATED state.")
+ .map(|s| vec![ImapRes::Status(s)])
+ .map_err(Error::msg),
+ },
+ flow::State::Selected(user, mailbox) => match req.body {
+ CommandBody::Capability => anonymous::capability().await, // we use the same implem for now
+ CommandBody::Fetch { sequence_set, attributes, uid, } => selected::fetch(sequence_set, attributes, uid).await,
+ _ => Status::no(Some(msg.req.tag.clone()), None, "This command is not available in the SELECTED state.")
+ .map(|s| vec![ImapRes::Status(s)])
+ .map_err(Error::msg),
+ },
+ flow::State::Logout => Status::bad(Some(msg.req.tag.clone()), None, "No commands are allowed in the LOGOUT state.")
+ .map(|s| vec![ImapRes::Status(s)])
+ .map_err(Error::msg),
+ }
+ */
+
+ let imap_res = match cmd_res {
+ Ok(new_state, imap_res) => {
+ self.state = new_state;
+ Ok(imap_res)
+ },
+ Err(e) if Ok(be) = e.downcast::<BalError>() => Err(be),
+ Err(e) => {
+ tracing::warn!(error=%e, "internal.error");
+ Ok(Status::bad(Some(msg.req.tag.clone()), None, "Internal error")
+ .map(|s| vec![ImapRes::Status(s)])
+ .map_err(|e| BalError::Text(e.to_string())))
+ }
+ };
+
+ //@FIXME I think we should quit this thread on error and having our manager watch it,
+ // and then abort the session as it is corrupted.
+ msg.tx.send(imap_res).unwrap_or_else(|e| {
+ tracing::warn!("failed to send imap response to manager: {:#?}", e)
+ });
+ }
+
+ //@FIXME add more info about the runner
+ tracing::debug!("exiting runner");
+ }
+}