mox IMAP4rev2 service endpoint instance on returned bidirectional stream

imapserver/internals.go

@@ -0,0 +1,23 @@
+package imapserver
+
+import (
+	"crypto/tls"
+	"net"
+)
+
+// internalsStruct exports some private top-level identifiers
+type internalsStruct struct {
+	// LimitersInit configures mox’ connection rate limiting and max connections
+	LimitersInit func()
+	// Serve launches the mox imap server with storage using provided connection
+	Serve func(listenerName string, cid int64, tlsConfig *tls.Config, nc net.Conn, xtls bool, noRequireSTARTTLS bool)
+}
+
+// internalsValue exports some private top-level identifiers
+var internalsValue = internalsStruct{
+	LimitersInit: limitersInit,
+	Serve:        serve,
+}
+
+// Internals exports some private top-level identifiers
+func Internals() (internals internalsStruct) { return internalsValue }

imaptemp/close-oncer.go

@@ -0,0 +1,44 @@
+/*
+Written 2024 by Harald Rudell <[email protected]> (https://haraldrudell.github.io/haraldrudell/)
+*/
+
+package imaptemp
+
+import (
+	"net"
+	"sync/atomic"
+)
+
+// closeOncer ensures a net.Conn to have thread-safe idempotent observable Close
+type closeOncer struct {
+	net.Conn
+	CloseWait chan struct{}
+	IsClosed  atomic.Bool
+}
+
+// newCloseOncer returns a wrapper making the net.Conn to have thread-safe idempotent observable Close
+func newCloseOncer(conn net.Conn) (c net.Conn) {
+	return &closeOncer{
+		Conn:      conn,
+		CloseWait: make(chan struct{}),
+	}
+}
+
+// Close is thread-safe idempotent observable
+//   - only the winner thread actually closing receives a possible error
+//   - no thread returns prior to the connection being closed
+//   - Close can be awaited by <-c.CloseWait
+//   - Close is observable by c.IsClosed.Load()
+func (c *closeOncer) Close() (err error) {
+	if !c.IsClosed.CompareAndSwap(false, true) {
+		// loser thread gets to wait
+		<-c.CloseWait
+		return
+	}
+	defer close(c.CloseWait)
+
+	// winner thread does close
+	err = c.Conn.Close()
+
+	return
+}

imaptemp/domains.conf

@@ -0,0 +1,21 @@
+Domains:
+	mox.example:
+		LocalpartCaseSensitive: false
+Accounts:
+	mjl:
+		Domain: mox.example
+		Destinations:
+			[email protected]: nil
+			""@mox.example: nil
+		JunkFilter:
+			Threshold: 0.95
+			Params:
+				Twograms: true
+				MaxPower: 0.1
+				TopWords: 10
+				IgnoreWords: 0.1
+	limit:
+		Domain: mox.example
+		Destinations:
+			[email protected]: nil
+		QuotaMessageSize: 1