use std::num::NonZeroU32; use std::sync::Arc; use anyhow::{anyhow, Error, Result}; use futures::stream::{FuturesOrdered, StreamExt}; use imap_codec::imap_types::core::Charset; use imap_codec::imap_types::fetch::{MacroOrMessageDataItemNames, MessageDataItem}; use imap_codec::imap_types::flag::{Flag, FlagFetch, FlagPerm, StoreResponse, StoreType}; use imap_codec::imap_types::response::{Code, Data, Status}; use imap_codec::imap_types::search::SearchKey; use imap_codec::imap_types::sequence::SequenceSet; use crate::mail::mailbox::Mailbox; use crate::mail::query::QueryScope; use crate::mail::snapshot::FrozenMailbox; use crate::mail::uidindex::{ImapUid, ImapUidvalidity}; use crate::imap::attributes::AttributesProxy; use crate::imap::flags; use crate::imap::index::Index; use crate::imap::mail_view::{MailView, SeenFlag}; use crate::imap::response::Body; use crate::imap::search; const DEFAULT_FLAGS: [Flag; 5] = [ Flag::Seen, Flag::Answered, Flag::Flagged, Flag::Deleted, Flag::Draft, ]; /// A MailboxView is responsible for giving the client the information /// it needs about a mailbox, such as an initial summary of the mailbox's /// content and continuous updates indicating when the content /// of the mailbox has been changed. /// To do this, it keeps a variable `known_state` that corresponds to /// what the client knows, and produces IMAP messages to be sent to the /// client that go along updates to `known_state`. pub struct MailboxView(pub FrozenMailbox); impl MailboxView { /// Creates a new IMAP view into a mailbox. pub async fn new(mailbox: Arc) -> Self { Self(mailbox.frozen().await) } /// Create an updated view, useful to make a diff /// between what the client knows and new stuff /// Produces a set of IMAP responses describing the change between /// what the client knows and what is actually in the mailbox. /// This does NOT trigger a sync, it bases itself on what is currently /// loaded in RAM by Bayou. pub async fn update(&mut self) -> Result>> { let old_snapshot = self.0.update().await; let new_snapshot = &self.0.snapshot; let mut data = Vec::::new(); // Calculate diff between two mailbox states // See example in IMAP RFC in section on NOOP command: // we want to produce something like this: // C: a047 NOOP // S: * 22 EXPUNGE // S: * 23 EXISTS // S: * 14 FETCH (UID 1305 FLAGS (\Seen \Deleted)) // S: a047 OK Noop completed // In other words: // - notify client of expunged mails // - if new mails arrived, notify client of number of existing mails // - if flags changed for existing mails, tell client // (for this last step: if uidvalidity changed, do nothing, // just notify of new uidvalidity and they will resync) // - notify client of expunged mails let mut n_expunge = 0; for (i, (_uid, uuid)) in old_snapshot.idx_by_uid.iter().enumerate() { if !new_snapshot.table.contains_key(uuid) { data.push(Body::Data(Data::Expunge( NonZeroU32::try_from((i + 1 - n_expunge) as u32).unwrap(), ))); n_expunge += 1; } } // - if new mails arrived, notify client of number of existing mails if new_snapshot.table.len() != old_snapshot.table.len() - n_expunge || new_snapshot.uidvalidity != old_snapshot.uidvalidity { data.push(self.exists_status()?); } if new_snapshot.uidvalidity != old_snapshot.uidvalidity { // TODO: do we want to push less/more info than this? data.push(self.uidvalidity_status()?); data.push(self.uidnext_status()?); } else { // - if flags changed for existing mails, tell client for (i, (_uid, uuid)) in new_snapshot.idx_by_uid.iter().enumerate() { let old_mail = old_snapshot.table.get(uuid); let new_mail = new_snapshot.table.get(uuid); if old_mail.is_some() && old_mail != new_mail { if let Some((uid, flags)) = new_mail { data.push(Body::Data(Data::Fetch { seq: NonZeroU32::try_from((i + 1) as u32).unwrap(), items: vec![ MessageDataItem::Uid(*uid), MessageDataItem::Flags( flags.iter().filter_map(|f| flags::from_str(f)).collect(), ), ] .try_into()?, })); } } } } Ok(data) } /// Generates the necessary IMAP messages so that the client /// has a satisfactory summary of the current mailbox's state. /// These are the messages that are sent in response to a SELECT command. pub fn summary(&self) -> Result>> { let mut data = Vec::::new(); data.push(self.exists_status()?); data.push(self.recent_status()?); data.extend(self.flags_status()?.into_iter()); data.push(self.uidvalidity_status()?); data.push(self.uidnext_status()?); Ok(data) } pub async fn store<'a>( &mut self, sequence_set: &SequenceSet, kind: &StoreType, _response: &StoreResponse, flags: &[Flag<'a>], is_uid_store: &bool, ) -> Result>> { self.0.sync().await?; let flags = flags.iter().map(|x| x.to_string()).collect::>(); let mails = self.index().fetch(sequence_set, *is_uid_store)?; for mi in mails.iter() { match kind { StoreType::Add => { self.0.mailbox.add_flags(mi.uuid, &flags[..]).await?; } StoreType::Remove => { self.0.mailbox.del_flags(mi.uuid, &flags[..]).await?; } StoreType::Replace => { self.0.mailbox.set_flags(mi.uuid, &flags[..]).await?; } } } // @TODO: handle _response self.update().await } pub async fn expunge(&mut self) -> Result>> { self.0.sync().await?; let state = self.0.peek().await; let deleted_flag = Flag::Deleted.to_string(); let msgs = state .table .iter() .filter(|(_uuid, (_uid, flags))| flags.iter().any(|x| *x == deleted_flag)) .map(|(uuid, _)| *uuid); for msg in msgs { self.0.mailbox.delete(msg).await?; } self.update().await } pub async fn copy( &self, sequence_set: &SequenceSet, to: Arc, is_uid_copy: &bool, ) -> Result<(ImapUidvalidity, Vec<(ImapUid, ImapUid)>)> { let mails = self.index().fetch(sequence_set, *is_uid_copy)?; let mut new_uuids = vec![]; for mi in mails.iter() { new_uuids.push(to.copy_from(&self.0.mailbox, mi.uuid).await?); } let mut ret = vec![]; let to_state = to.current_uid_index().await; for (mi, new_uuid) in mails.iter().zip(new_uuids.iter()) { let dest_uid = to_state .table .get(new_uuid) .ok_or(anyhow!("copied mail not in destination mailbox"))? .0; ret.push((mi.uid, dest_uid)); } Ok((to_state.uidvalidity, ret)) } pub async fn r#move( &mut self, sequence_set: &SequenceSet, to: Arc, is_uid_copy: &bool, ) -> Result<(ImapUidvalidity, Vec<(ImapUid, ImapUid)>, Vec>)> { let mails = self.index().fetch(sequence_set, *is_uid_copy)?; for mi in mails.iter() { to.move_from(&self.0.mailbox, mi.uuid).await?; } let mut ret = vec![]; let to_state = to.current_uid_index().await; for mi in mails.iter() { let dest_uid = to_state .table .get(&mi.uuid) .ok_or(anyhow!("moved mail not in destination mailbox"))? .0; ret.push((mi.uid, dest_uid)); } let update = self.update().await?; Ok((to_state.uidvalidity, ret, update)) } /// Looks up state changes in the mailbox and produces a set of IMAP /// responses describing the new state. pub async fn fetch<'b>( &self, sequence_set: &SequenceSet, attributes: &'b MacroOrMessageDataItemNames<'static>, is_uid_fetch: &bool, ) -> Result>> { // [1/6] Pre-compute data // a. what are the uuids of the emails we want? // b. do we need to fetch the full body? let ap = AttributesProxy::new(attributes, *is_uid_fetch); let query_scope = match ap.need_body() { true => QueryScope::Full, _ => QueryScope::Partial, }; let mail_idx_list = self.index().fetch(sequence_set, *is_uid_fetch)?; // [2/6] Fetch the emails let uuids = mail_idx_list .iter() .map(|midx| midx.uuid) .collect::>(); let query_result = self.0.query(&uuids, query_scope).fetch().await?; // [3/6] Derive an IMAP-specific view from the results, apply the filters let views = query_result .iter() .zip(mail_idx_list.into_iter()) .map(|(qr, midx)| MailView::new(qr, midx)) .collect::, _>>()?; // [4/6] Apply the IMAP transformation, bubble up any error // We get 2 results: // - The one we send to the client // - The \Seen flags we must set internally let (flag_mgmt, imap_ret): (Vec<_>, Vec<_>) = views .iter() .map(|mv| mv.filter(&ap).map(|(body, seen)| ((mv, seen), body))) .collect::, _>>()? .into_iter() .unzip(); // [5/6] Register the \Seen flags flag_mgmt .iter() .filter(|(_mv, seen)| matches!(seen, SeenFlag::MustAdd)) .map(|(mv, _seen)| async move { let seen_flag = Flag::Seen.to_string(); self.0 .mailbox .add_flags(*mv.query_result.uuid(), &[seen_flag]) .await?; Ok::<_, anyhow::Error>(()) }) .collect::>() .collect::>() .await .into_iter() .collect::>()?; // [6/6] Build the final result that will be sent to the client. Ok(imap_ret) } /// A naive search implementation... pub async fn search<'a>( &self, _charset: &Option>, search_key: &SearchKey<'a>, uid: bool, ) -> Result>> { // 1. Compute the subset of sequence identifiers we need to fetch // based on the search query let crit = search::Criteria(search_key); let (seq_set, seq_type) = crit.to_sequence_set(); // 2. Get the selection let selection = self.index().fetch(&seq_set, seq_type.is_uid())?; // 3. Filter the selection based on the ID / UID / Flags let (kept_idx, to_fetch) = crit.filter_on_idx(&selection); // 4. Fetch additional info about the emails let query_scope = crit.query_scope(); let uuids = to_fetch.iter().map(|midx| midx.uuid).collect::>(); let query_result = self.0.query(&uuids, query_scope).fetch().await?; // 5. If needed, filter the selection based on the body let kept_query = crit.filter_on_query(&to_fetch, &query_result)?; // 6. Format the result according to the client's taste: // either return UID or ID. let final_selection = kept_idx.into_iter().chain(kept_query.into_iter()); let selection_fmt = match uid { true => final_selection.map(|in_idx| in_idx.uid).collect(), _ => final_selection.map(|in_idx| in_idx.i).collect(), }; Ok(vec![Body::Data(Data::Search(selection_fmt))]) } // ---- fn index<'a>(&'a self) -> Index<'a> { Index(&self.0.snapshot) } /// Produce an OK [UIDVALIDITY _] message corresponding to `known_state` fn uidvalidity_status(&self) -> Result> { let uid_validity = Status::ok( None, Some(Code::UidValidity(self.uidvalidity())), "UIDs valid", ) .map_err(Error::msg)?; Ok(Body::Status(uid_validity)) } pub(crate) fn uidvalidity(&self) -> ImapUidvalidity { self.0.snapshot.uidvalidity } /// Produce an OK [UIDNEXT _] message corresponding to `known_state` fn uidnext_status(&self) -> Result> { let next_uid = Status::ok( None, Some(Code::UidNext(self.uidnext())), "Predict next UID", ) .map_err(Error::msg)?; Ok(Body::Status(next_uid)) } pub(crate) fn uidnext(&self) -> ImapUid { self.0.snapshot.uidnext } /// Produce an EXISTS message corresponding to the number of mails /// in `known_state` fn exists_status(&self) -> Result> { Ok(Body::Data(Data::Exists(self.exists()?))) } pub(crate) fn exists(&self) -> Result { Ok(u32::try_from(self.0.snapshot.idx_by_uid.len())?) } /// Produce a RECENT message corresponding to the number of /// recent mails in `known_state` fn recent_status(&self) -> Result> { Ok(Body::Data(Data::Recent(self.recent()?))) } pub(crate) fn recent(&self) -> Result { let recent = self .0 .snapshot .idx_by_flag .get(&"\\Recent".to_string()) .map(|os| os.len()) .unwrap_or(0); Ok(u32::try_from(recent)?) } /// Produce a FLAGS and a PERMANENTFLAGS message that indicates /// the flags that are in `known_state` + default flags fn flags_status(&self) -> Result>> { let mut body = vec![]; // 1. Collecting all the possible flags in the mailbox // 1.a Fetch them from our index let mut known_flags: Vec = self .0 .snapshot .idx_by_flag .flags() .filter_map(|f| match flags::from_str(f) { Some(FlagFetch::Flag(fl)) => Some(fl), _ => None, }) .collect(); // 1.b Merge it with our default flags list for f in DEFAULT_FLAGS.iter() { if !known_flags.contains(f) { known_flags.push(f.clone()); } } // 1.c Create the IMAP message body.push(Body::Data(Data::Flags(known_flags.clone()))); // 2. Returning flags that are persisted // 2.a Always advertise our default flags let mut permanent = DEFAULT_FLAGS .iter() .map(|f| FlagPerm::Flag(f.clone())) .collect::>(); // 2.b Say that we support any keyword flag permanent.push(FlagPerm::Asterisk); // 2.c Create the IMAP message let permanent_flags = Status::ok( None, Some(Code::PermanentFlags(permanent)), "Flags permitted", ) .map_err(Error::msg)?; body.push(Body::Status(permanent_flags)); // Done! Ok(body) } pub(crate) fn unseen_count(&self) -> usize { let total = self.0.snapshot.table.len(); let seen = self .0 .snapshot .idx_by_flag .get(&Flag::Seen.to_string()) .map(|x| x.len()) .unwrap_or(0); total - seen } } #[cfg(test)] mod tests { use super::*; use imap_codec::encode::Encoder; use imap_codec::imap_types::core::NonEmptyVec; use imap_codec::imap_types::fetch::Section; use imap_codec::imap_types::fetch::{MacroOrMessageDataItemNames, MessageDataItemName}; use imap_codec::imap_types::response::Response; use imap_codec::ResponseCodec; use std::fs; use crate::cryptoblob; use crate::imap::index::MailIndex; use crate::imap::mail_view::MailView; use crate::imap::mime_view; use crate::mail::mailbox::MailMeta; use crate::mail::query::QueryResult; use crate::mail::unique_ident; #[test] fn mailview_body_ext() -> Result<()> { let ap = AttributesProxy::new( &MacroOrMessageDataItemNames::MessageDataItemNames(vec![ MessageDataItemName::BodyExt { section: Some(Section::Header(None)), partial: None, peek: false, }, ]), false, ); let key = cryptoblob::gen_key(); let meta = MailMeta { internaldate: 0u64, headers: vec![], message_key: key, rfc822_size: 8usize, }; let index_entry = (NonZeroU32::MIN, vec![]); let mail_in_idx = MailIndex { i: NonZeroU32::MIN, uid: index_entry.0, uuid: unique_ident::gen_ident(), flags: &index_entry.1, }; let rfc822 = b"Subject: hello\r\nFrom: a@a.a\r\nTo: b@b.b\r\nDate: Thu, 12 Oct 2023 08:45:28 +0000\r\n\r\nhello world"; let qr = QueryResult::FullResult { uuid: mail_in_idx.uuid.clone(), index: &index_entry, metadata: meta, content: rfc822.to_vec(), }; let mv = MailView::new(&qr, mail_in_idx)?; let (res_body, _seen) = mv.filter(&ap)?; let fattr = match res_body { Body::Data(Data::Fetch { seq: _seq, items: attr, }) => Ok(attr), _ => Err(anyhow!("Not a fetch body")), }?; assert_eq!(fattr.as_ref().len(), 1); let (sec, _orig, _data) = match &fattr.as_ref()[0] { MessageDataItem::BodyExt { section, origin, data, } => Ok((section, origin, data)), _ => Err(anyhow!("not a body ext message attribute")), }?; assert_eq!(sec.as_ref().unwrap(), &Section::Header(None)); Ok(()) } /// Future automated test. We use lossy utf8 conversion + lowercase everything, /// so this test might allow invalid results. But at least it allows us to quickly test a /// large variety of emails. /// Keep in mind that special cases must still be tested manually! #[test] fn fetch_body() -> Result<()> { let prefixes = [ /* *** MY OWN DATASET *** */ "tests/emails/dxflrs/0001_simple", "tests/emails/dxflrs/0002_mime", "tests/emails/dxflrs/0003_mime-in-mime", "tests/emails/dxflrs/0004_msg-in-msg", // eml_codec do not support continuation for the moment //"tests/emails/dxflrs/0005_mail-parser-readme", "tests/emails/dxflrs/0006_single-mime", "tests/emails/dxflrs/0007_raw_msg_in_rfc822", /* *** (STRANGE) RFC *** */ //"tests/emails/rfc/000", // must return text/enriched, we return text/plain //"tests/emails/rfc/001", // does not recognize the multipart/external-body, breaks the // whole parsing //"tests/emails/rfc/002", // wrong date in email //"tests/emails/rfc/003", // dovecot fixes \r\r: the bytes number is wrong + text/enriched /* *** THIRD PARTY *** */ //"tests/emails/thirdparty/000", // dovecot fixes \r\r: the bytes number is wrong //"tests/emails/thirdparty/001", // same "tests/emails/thirdparty/002", // same /* *** LEGACY *** */ //"tests/emails/legacy/000", // same issue with \r\r ]; for pref in prefixes.iter() { println!("{}", pref); let txt = fs::read(format!("{}.eml", pref))?; let oracle = fs::read(format!("{}.dovecot.body", pref))?; let message = eml_codec::parse_message(&txt).unwrap().1; let test_repr = Response::Data(Data::Fetch { seq: NonZeroU32::new(1).unwrap(), items: NonEmptyVec::from(MessageDataItem::Body(mime_view::bodystructure( &message.child, )?)), }); let test_bytes = ResponseCodec::new().encode(&test_repr).dump(); let test_str = String::from_utf8_lossy(&test_bytes).to_lowercase(); let oracle_str = format!("* 1 FETCH {}\r\n", String::from_utf8_lossy(&oracle)).to_lowercase(); println!("aerogramme: {}\n\ndovecot: {}\n\n", test_str, oracle_str); //println!("\n\n {} \n\n", String::from_utf8_lossy(&resp)); assert_eq!(test_str, oracle_str); } Ok(()) } }