imapserver: Support RECENT for IMAP4rev1 servers

Author: foxcpp

capability.go

@@ -107,6 +107,14 @@ func (set CapSet) has(c Cap) bool {
 return ok
 }
 
+func (set CapSet) Copy() CapSet {
+newSet := make(CapSet, len(set))
+for c := range set {
+newSet[c] = struct{}{}
+}
+return newSet
+}
+
 // Has checks whether a capability is supported.
 //
 // Some capabilities are implied by others, as such Has may return true even if

imapclient/status.go

@@ -37,6 +37,9 @@ func (c *Client) Status(mailbox string, options *imap.StatusOptions) *StatusComm
 if options == nil {
 options = new(imap.StatusOptions)
 }
+if options.NumRecent {
+panic("StatusOptions.NumRecent is not supported in imapclient")
+}
 
 cmd := &StatusCommand{mailbox: mailbox}
 enc := c.beginCommand("STATUS", cmd)

imapserver/conn.go

@@ -85,6 +85,13 @@ func (c *Conn) Bye(text string) error {
 return closeErr
 }
 
+func (c *Conn) EnabledCaps() imap.CapSet {
+c.mutex.Lock()
+defer c.mutex.Unlock()
+
+return c.enabled.Copy()
+}
+
 func (c *Conn) serve() {
 defer func() {
 if v := recover(); v != nil {
@@ -585,6 +592,14 @@ func (w *UpdateWriter) WriteNumMessages(n uint32) error {
 return w.conn.writeExists(n)
 }
 
+// WriteNumRecent writes an RECENT response (not used in IMAP4rev2, will be ignored).
+func (w *UpdateWriter) WriteNumRecent(n uint32) error {
+if w.conn.enabled.Has(imap.CapIMAP4rev2) || !w.conn.server.options.caps().Has(imap.CapIMAP4rev1) {
+return nil
+}
+return w.conn.writeObsoleteRecent(n)
+}
+
 // WriteMailboxFlags writes a FLAGS response.
 func (w *UpdateWriter) WriteMailboxFlags(flags []imap.Flag) error {
 return w.conn.writeFlags(flags)

imapserver/list.go

@@ -10,7 +10,7 @@ import (
 )
 
 func (c *Conn) handleList(dec *imapwire.Decoder) error {
-ref, pattern, options, returnRecent, err := readListCmd(dec)
+ref, pattern, options, err := readListCmd(dec)
 if err != nil {
 return err
 }
@@ -20,9 +20,8 @@ func (c *Conn) handleList(dec *imapwire.Decoder) error {
 }
 
 w := &ListWriter{
-conn: c,
-options: options,
-returnRecent: returnRecent,
+conn: c,
+options: options,
 }
 return c.session.List(w, ref, pattern, options)
 }
@@ -117,11 +116,11 @@ func (c *Conn) writeLSub(data *imap.ListData) error {
 return enc.CRLF()
 }
 
-func readListCmd(dec *imapwire.Decoder) (ref string, patterns []string, options *imap.ListOptions, returnRecent bool, err error) {
+func readListCmd(dec *imapwire.Decoder) (ref string, patterns []string, options *imap.ListOptions, err error) {
 options = &imap.ListOptions{}
 
 if !dec.ExpectSP() {
-return "", nil, nil, false, dec.Err()
+return "", nil, nil, dec.Err()
 }
 
 hasSelectOpts, err := dec.List(func() error {
@@ -142,14 +141,14 @@ func readListCmd(dec *imapwire.Decoder) (ref string, patterns []string, options
 return nil
 })
 if err != nil {
-return "", nil, nil, false, fmt.Errorf("in list-select-opts: %w", err)
+return "", nil, nil, fmt.Errorf("in list-select-opts: %w", err)
 }
 if hasSelectOpts && !dec.ExpectSP() {
-return "", nil, nil, false, dec.Err()
+return "", nil, nil, dec.Err()
 }
 
 if !dec.ExpectMailbox(&ref) || !dec.ExpectSP() {
-return "", nil, nil, false, dec.Err()
+return "", nil, nil, dec.Err()
 }
 
 hasPatterns, err := dec.List(func() error {
@@ -160,13 +159,13 @@ func readListCmd(dec *imapwire.Decoder) (ref string, patterns []string, options
 return err
 })
 if err != nil {
-return "", nil, nil, false, err
+return "", nil, nil, err
 } else if hasPatterns && len(patterns) == 0 {
-return "", nil, nil, false, newClientBugError("LIST-EXTENDED requires a non-empty parenthesized pattern list")
+return "", nil, nil, newClientBugError("LIST-EXTENDED requires a non-empty parenthesized pattern list")
 } else if !hasPatterns {
 pattern, err := readListMailbox(dec)
 if err != nil {
-return "", nil, nil, false, err
+return "", nil, nil, err
 }
 if pattern != "" {
 patterns = append(patterns, pattern)
@@ -176,26 +175,26 @@ func readListCmd(dec *imapwire.Decoder) (ref string, patterns []string, options
 if dec.SP() { // list-return-opts
 var atom string
 if !dec.ExpectAtom(&atom) || !dec.Expect(strings.EqualFold(atom, "RETURN"), "RETURN") || !dec.ExpectSP() {
-return "", nil, nil, false, dec.Err()
+return "", nil, nil, dec.Err()
 }
 
 err := dec.ExpectList(func() error {
-return readReturnOption(dec, options, &returnRecent)
+return readReturnOption(dec, options)
 })
 if err != nil {
-return "", nil, nil, false, fmt.Errorf("in list-return-opts: %w", err)
+return "", nil, nil, fmt.Errorf("in list-return-opts: %w", err)
 }
 }
 
 if !dec.ExpectCRLF() {
-return "", nil, nil, false, dec.Err()
+return "", nil, nil, dec.Err()
 }
 
 if options.SelectRecursiveMatch && !options.SelectSubscribed {
-return "", nil, nil, false, newClientBugError("The LIST RECURSIVEMATCH select option requires SUBSCRIBED")
+return "", nil, nil, newClientBugError("The LIST RECURSIVEMATCH select option requires SUBSCRIBED")
 }
 
-return ref, patterns, options, returnRecent, nil
+return ref, patterns, options, nil
 }
 
 func readListMailbox(dec *imapwire.Decoder) (string, error) {
@@ -219,7 +218,7 @@ func isListChar(ch byte) bool {
 }
 }
 
-func readReturnOption(dec *imapwire.Decoder, options *imap.ListOptions, recent *bool) error {
+func readReturnOption(dec *imapwire.Decoder, options *imap.ListOptions) error {
 var name string
 if !dec.ExpectAtom(&name) {
 return dec.Err()
@@ -236,11 +235,7 @@ func readReturnOption(dec *imapwire.Decoder, options *imap.ListOptions, recent *
 }
 options.ReturnStatus = new(imap.StatusOptions)
 return dec.ExpectList(func() error {
-isRecent, err := readStatusItem(dec, options.ReturnStatus)
-if isRecent {
-*recent = true
-}
-return err
+return readStatusItem(dec, options.ReturnStatus)
 })
 default:
 return newClientBugError("Unknown LIST RETURN options")
@@ -250,10 +245,9 @@ func readReturnOption(dec *imapwire.Decoder, options *imap.ListOptions, recent *
 
 // ListWriter writes LIST responses.
 type ListWriter struct {
-conn *Conn
-options *imap.ListOptions
-returnRecent bool
-lsub bool
+conn *Conn
+options *imap.ListOptions
+lsub bool
 }
 
 // WriteList writes a single LIST response for a mailbox.
@@ -266,7 +260,7 @@ func (w *ListWriter) WriteList(data *imap.ListData) error {
 return err
 }
 if w.options.ReturnStatus != nil && data.Status != nil {
-if err := w.conn.writeStatus(data.Status, w.options.ReturnStatus, w.returnRecent); err != nil {
+if err := w.conn.writeStatus(data.Status, w.options.ReturnStatus); err != nil {
 return err
 }
 }

imapserver/select.go

@@ -42,7 +42,7 @@ func (c *Conn) handleSelect(tag string, dec *imapwire.Decoder, readOnly bool) er
 return err
 }
 if !c.enabled.Has(imap.CapIMAP4rev2) {
-if err := c.writeObsoleteRecent(); err != nil {
+if err := c.writeObsoleteRecent(data.NumRecent); err != nil {
 return err
 }
 }
@@ -115,10 +115,10 @@ func (c *Conn) writeExists(numMessages uint32) error {
 return enc.Atom("*").SP().Number(numMessages).SP().Atom("EXISTS").CRLF()
 }
 
-func (c *Conn) writeObsoleteRecent() error {
+func (c *Conn) writeObsoleteRecent(n uint32) error {
 enc := newResponseEncoder(c)
 defer enc.end()
-return enc.Atom("*").SP().Number(0).SP().Atom("RECENT").CRLF()
+return enc.Atom("*").SP().Number(n).SP().Atom("RECENT").CRLF()
 }
 
 func (c *Conn) writeUIDValidity(uidValidity uint32) error {

imapserver/status.go

@@ -14,13 +14,10 @@ func (c *Conn) handleStatus(dec *imapwire.Decoder) error {
 }
 
 var options imap.StatusOptions
-recent := false
 err := dec.ExpectList(func() error {
-isRecent, err := readStatusItem(dec, &options)
+err := readStatusItem(dec, &options)
 if err != nil {
 return err
-} else if isRecent {
-recent = true
 }
 return nil
 })
@@ -32,6 +29,13 @@ func (c *Conn) handleStatus(dec *imapwire.Decoder) error {
 return dec.Err()
 }
 
+if options.NumRecent && !c.server.options.caps().Has(imap.CapIMAP4rev1) {
+return &imap.Error{
+Type: imap.StatusResponseTypeBad,
+Text: "Unknown STATUS data item",
+}
+}
+
 if err := c.checkState(imap.ConnStateAuthenticated); err != nil {
 return err
 }
@@ -41,10 +45,10 @@ func (c *Conn) handleStatus(dec *imapwire.Decoder) error {
 return err
 }
 
-return c.writeStatus(data, &options, recent)
+return c.writeStatus(data, &options)
 }
 
-func (c *Conn) writeStatus(data *imap.StatusData, options *imap.StatusOptions, recent bool) error {
+func (c *Conn) writeStatus(data *imap.StatusData, options *imap.StatusOptions) error {
 enc := newResponseEncoder(c)
 defer enc.end()
 
@@ -79,18 +83,18 @@ func (c *Conn) writeStatus(data *imap.StatusData, options *imap.StatusOptions, r
 if options.DeletedStorage {
 listEnc.Item().Atom("DELETED-STORAGE").SP().Number64(*data.DeletedStorage)
 }
-if recent {
-listEnc.Item().Atom("RECENT").SP().Number(0)
+if options.NumRecent {
+listEnc.Item().Atom("RECENT").SP().Number(*data.NumRecent)
 }
 listEnc.End()
 
 return enc.CRLF()
 }
 
-func readStatusItem(dec *imapwire.Decoder, options *imap.StatusOptions) (isRecent bool, err error) {
+func readStatusItem(dec *imapwire.Decoder, options *imap.StatusOptions) error {
 var name string
 if !dec.ExpectAtom(&name) {
-return false, dec.Err()
+return dec.Err()
 }
 switch strings.ToUpper(name) {
 case "MESSAGES":
@@ -110,12 +114,12 @@ func readStatusItem(dec *imapwire.Decoder, options *imap.StatusOptions) (isRecen
 case "DELETED-STORAGE":
 options.DeletedStorage = true
 case "RECENT":
-isRecent = true
+options.NumRecent = true
 default:
-return false, &imap.Error{
+return &imap.Error{
 Type: imap.StatusResponseTypeBad,
 Text: "Unknown STATUS data item",
 }
 }
-return isRecent, nil
+return nil
 }

select.go

@@ -16,6 +16,9 @@ type SelectData struct {
 PermanentFlags []Flag
 // Number of messages in this mailbox (aka. "EXISTS")
 NumMessages uint32
+// Number of recent messages in this mailbox ("RECENT") (Obsolete, IMAP4rev1 only).
+// Server-only, not supported in imapclient.
+NumRecent uint32
 UIDNext UID
 UIDValidity uint32
 

status.go

@@ -3,6 +3,7 @@ package imap
 // StatusOptions contains options for the STATUS command.
 type StatusOptions struct {
 NumMessages bool
+NumRecent bool // Obsolete, IMAP4rev1 only. Server-only, not supported in imapclient.
 UIDNext bool
 UIDValidity bool
 NumUnseen bool
@@ -21,6 +22,7 @@ type StatusData struct {
 Mailbox string
 
 NumMessages *uint32
+NumRecent *uint32 // Obsolete, IMAP4rev1 only. Server-only, not supported in imapclient.
 UIDNext UID
 UIDValidity uint32
 NumUnseen *uint32