49 lines
1.4 KiB
Go
49 lines
1.4 KiB
Go
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package imapserver
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import (
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"net"
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"time"
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)
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// IdleTimeoutListener wraps a listener so every accepted connection gets a rolling
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// deadline extended by d on each read/write. Unlike SMTP (go-smtp's Server.ReadTimeout/
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// WriteTimeout), go-imap/v2's imapserver.Options has no timeout knob at all, so an idle
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// or slow-drip connection can otherwise hold a goroutine (and a file descriptor) open
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// indefinitely. 30 minutes (the caller's chosen d) matches RFC 2177's guidance that an
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// IDLE-capable client re-issue IDLE at least that often, so a real IDLE session renews
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// its own deadline in time and is never cut off by this.
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func IdleTimeoutListener(inner net.Listener, d time.Duration) net.Listener {
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return &idleTimeoutListener{Listener: inner, d: d}
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}
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type idleTimeoutListener struct {
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net.Listener
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d time.Duration
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}
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func (l *idleTimeoutListener) Accept() (net.Conn, error) {
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conn, err := l.Listener.Accept()
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if err != nil {
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return nil, err
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}
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conn.SetDeadline(time.Now().Add(l.d))
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return &idleTimeoutConn{Conn: conn, d: l.d}, nil
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}
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type idleTimeoutConn struct {
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net.Conn
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d time.Duration
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}
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func (c *idleTimeoutConn) Read(b []byte) (int, error) {
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n, err := c.Conn.Read(b)
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c.Conn.SetDeadline(time.Now().Add(c.d))
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return n, err
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}
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func (c *idleTimeoutConn) Write(b []byte) (int, error) {
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n, err := c.Conn.Write(b)
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c.Conn.SetDeadline(time.Now().Add(c.d))
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return n, err
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}
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