// Listens for connections on the given listener and puts them in the channel.
// Blocks while still receiving connections.
// Returns an error on network problem, or nil if shutdown requested
func listenForConnections(l net.Listener, c chan net.Conn) error {
id, shutdownRequested := shutdown.AddShutdownListener("Connection listener")
defer shutdown.RoutineDone(id)
log.WithFields(log.Fields{
"listening_on": fmt.Sprintf("%v", l.Addr()),
"fqdn": config.GetFQDN(),
}).Info("Starting connection listener")
// shutdown using the strategy found here http://stackoverflow.com/a/13419724
quit := false
go func() {
<-shutdownRequested
quit = true
l.Close()
}()
for {
conn, err := l.Accept()
if err != nil {
if quit {
log.Info("Shutting down connection listener")
return nil
}
l.Close()
return err
}
c <- conn
}
}
func (c *Client) notifyServiceReady() error {
_, err := c.out.WriteString(fmt.Sprintf("220 %s ESMTP\r\n", config.GetFQDN()))
if err != nil {
return err
}
err = c.out.Flush()
return err
}
func (c *Client) notifyEhlo() error {
toWrite := fmt.Sprintf("250-%s supports ONE extension:\r\n",
config.GetFQDN()) +
"250-8BITMIME\r\n"
_, err := c.out.WriteString(toWrite)
if err != nil {
return err
}
err = c.out.Flush()
return err
}