mox/smtpserver/rejects.go
Mechiel Lukkien 577944310c
Improve expunged message/UID tracking in IMAP sessions, track synchronization history for mailboxes/annotations.
Keeping the message files around, and the message details in the database, is
useful for IMAP sessions that haven't seen/processed the removal of a message
yet and try to fetch it. Before, we would return errors. Similarly, a session
that has a mailbox selected that is removed can (at least in theory) still read
messages.

The mechanics to do this need keeping removed mailboxes around too. JMAP needs
that anyway, so we now keep modseq/createseq/expunged history for mailboxes
too. And while we're at it, for annotations as well.

For future JMAP support, we now also keep the mailbox parent id around for a
mailbox, with an upgrade step to set the field for existing mailboxes and
fixing up potential missing parents (which could possibly have happened in an
obscure corner case that I doubt anyone ran into).
2025-03-06 11:35:44 +01:00

71 lines
2.1 KiB
Go

package smtpserver
import (
"bytes"
"context"
"crypto/sha256"
"fmt"
"io"
"log/slog"
"os"
"github.com/mjl-/bstore"
"github.com/mjl-/mox/message"
"github.com/mjl-/mox/mlog"
"github.com/mjl-/mox/moxio"
"github.com/mjl-/mox/store"
)
// rejectPresent returns whether the message is already present in the rejects mailbox.
func rejectPresent(log mlog.Log, acc *store.Account, rejectsMailbox string, m *store.Message, f *os.File) (present bool, msgID string, hash []byte, rerr error) {
if p, err := message.Parse(log.Logger, false, store.FileMsgReader(m.MsgPrefix, f)); err != nil {
log.Infox("parsing reject message for message-id", err)
} else if header, err := p.Header(); err != nil {
log.Infox("parsing reject message header for message-id", err)
} else {
msgID, _, err = message.MessageIDCanonical(header.Get("Message-Id"))
if err != nil {
log.Debugx("parsing message-id for reject", err, slog.String("messageid", header.Get("Message-Id")))
}
}
// We must not read MsgPrefix, it will likely change for subsequent deliveries.
h := sha256.New()
if _, err := io.Copy(h, &moxio.AtReader{R: f}); err != nil {
log.Infox("copying reject message to hash", err)
} else {
hash = h.Sum(nil)
}
if msgID == "" && len(hash) == 0 {
return false, "", nil, fmt.Errorf("no message-id or hash for determining reject message presence")
}
var exists bool
var err error
acc.WithRLock(func() {
err = acc.DB.Read(context.TODO(), func(tx *bstore.Tx) error {
mb, err := acc.MailboxFind(tx, rejectsMailbox)
if err != nil {
return fmt.Errorf("looking for rejects mailbox: %w", err)
} else if mb == nil {
return nil
}
q := bstore.QueryTx[store.Message](tx)
q.FilterNonzero(store.Message{MailboxID: mb.ID})
q.FilterEqual("Expunged", false)
q.FilterFn(func(m store.Message) bool {
return msgID != "" && m.MessageID == msgID || len(hash) > 0 && bytes.Equal(m.MessageHash, hash)
})
exists, err = q.Exists()
return err
})
})
if err != nil {
return false, "", nil, fmt.Errorf("querying for presence of reject message: %w", err)
}
return exists, msgID, hash, nil
}