func setupRoutes(cfg config.WebConfig) {
	log.LogInfo("Theme templates mapped to '%v'", cfg.TemplateDir)
	log.LogInfo("Theme static content mapped to '%v'", cfg.PublicDir)

	r := mux.NewRouter()
	// Static content
	r.PathPrefix("/public/").Handler(http.StripPrefix("/public/",
		http.FileServer(http.Dir(cfg.PublicDir))))

	// Root
	r.Path("/").Handler(handler(RootIndex)).Name("RootIndex").Methods("GET")
	r.Path("/status").Handler(handler(RootStatus)).Name("RootStatus").Methods("GET")
	r.Path("/link/{name}/{id}").Handler(handler(MailboxLink)).Name("MailboxLink").Methods("GET")
	r.Path("/mailbox").Handler(handler(MailboxIndex)).Name("MailboxIndex").Methods("GET")
	r.Path("/mailbox/{name}").Handler(handler(MailboxList)).Name("MailboxList").Methods("GET")
	r.Path("/mailbox/{name}").Handler(handler(MailboxPurge)).Name("MailboxPurge").Methods("DELETE")
	r.Path("/mailbox/{name}/{id}").Handler(handler(MailboxShow)).Name("MailboxShow").Methods("GET")
	r.Path("/mailbox/{name}/{id}/html").Handler(handler(MailboxHtml)).Name("MailboxHtml").Methods("GET")
	r.Path("/mailbox/{name}/{id}/source").Handler(handler(MailboxSource)).Name("MailboxSource").Methods("GET")
	r.Path("/mailbox/{name}/{id}").Handler(handler(MailboxDelete)).Name("MailboxDelete").Methods("DELETE")
	r.Path("/mailbox/dattach/{name}/{id}/{num}/{file}").Handler(handler(MailboxDownloadAttach)).Name("MailboxDownloadAttach").Methods("GET")
	r.Path("/mailbox/vattach/{name}/{id}/{num}/{file}").Handler(handler(MailboxViewAttach)).Name("MailboxViewAttach").Methods("GET")

	// Register w/ HTTP
	Router = r
	http.Handle("/", Router)
}

// signalProcessor is a goroutine that handles OS signals
func signalProcessor(c <-chan os.Signal) {
	for {
		sig := <-c
		switch sig {
		case syscall.SIGHUP:
			// Rotate logs if configured
			if logf != nil {
				log.LogInfo("Recieved SIGHUP, cycling logfile")
				closeLogFile()
				openLogFile()
			} else {
				log.LogInfo("Ignoring SIGHUP, logfile not configured")
			}
		case syscall.SIGTERM:
			// Initiate shutdown
			log.LogInfo("Received SIGTERM, shutting down")
			go timedExit()
			web.Stop()
			if smtpServer != nil {
				smtpServer.Stop()
			} else {
				log.LogError("smtpServer was nil during shutdown")
			}
		}
	}
}

func StartRetentionScanner(ds DataStore) {
	cfg := config.GetDataStoreConfig()
	expRetentionPeriod.Set(int64(cfg.RetentionMinutes * 60))
	if cfg.RetentionMinutes > 0 {
		// Retention scanning enabled
		log.LogInfo("Retention configured for %v minutes", cfg.RetentionMinutes)
		go retentionScanner(ds, time.Duration(cfg.RetentionMinutes)*time.Minute,
			time.Duration(cfg.RetentionSleep)*time.Millisecond)
	} else {
		log.LogInfo("Retention scanner disabled")
	}
}

// Start() the web server
func Start() {
	addr := fmt.Sprintf("%v:%v", webConfig.Ip4address, webConfig.Ip4port)
	server := &http.Server{
		Addr:         addr,
		Handler:      nil,
		ReadTimeout:  60 * time.Second,
		WriteTimeout: 60 * time.Second,
	}

	// We don't use ListenAndServe because it lacks a way to close the listener
	log.LogInfo("HTTP listening on TCP4 %v", addr)
	var err error
	listener, err = net.Listen("tcp", addr)
	if err != nil {
		log.LogError("HTTP failed to start TCP4 listener: %v", err)
		// TODO More graceful early-shutdown procedure
		panic(err)
	}

	err = server.Serve(listener)
	if shutdown {
		log.LogTrace("HTTP server shutting down on request")
	} else if err != nil {
		log.LogError("HTTP server failed: %v", err)
	}
}

// Main listener loop
func (s *Server) Start() {
	cfg := config.GetPop3Config()
	addr, err := net.ResolveTCPAddr("tcp4", fmt.Sprintf("%v:%v",
		cfg.Ip4address, cfg.Ip4port))
	if err != nil {
		log.LogError("POP3 Failed to build tcp4 address: %v", err)
		// TODO More graceful early-shutdown procedure
		panic(err)
	}

	log.LogInfo("POP3 listening on TCP4 %v", addr)
	s.listener, err = net.ListenTCP("tcp4", addr)
	if err != nil {
		log.LogError("POP3 failed to start tcp4 listener: %v", err)
		// TODO More graceful early-shutdown procedure
		panic(err)
	}

	// Handle incoming connections
	var tempDelay time.Duration
	for sid := 1; ; sid++ {
		if conn, err := s.listener.Accept(); err != nil {
			if nerr, ok := err.(net.Error); ok && nerr.Temporary() {
				// Temporary error, sleep for a bit and try again
				if tempDelay == 0 {
					tempDelay = 5 * time.Millisecond
				} else {
					tempDelay *= 2
				}
				if max := 1 * time.Second; tempDelay > max {
					tempDelay = max
				}
				log.LogError("POP3 accept error: %v; retrying in %v", err, tempDelay)
				time.Sleep(tempDelay)
				continue
			} else {
				if s.shutdown {
					log.LogTrace("POP3 listener shutting down on request")
					return
				}
				// TODO Implement a max error counter before shutdown?
				// or maybe attempt to restart POP3
				panic(err)
			}
		} else {
			tempDelay = 0
			s.waitgroup.Add(1)
			go s.startSession(sid, conn)
		}
	}
}

// NewMessage creates a new Message object and sets the Date and Id fields.
// It will also delete messages over messageCap if configured.
func (mb *FileMailbox) NewMessage() (Message, error) {
	// Load index
	if !mb.indexLoaded {
		if err := mb.readIndex(); err != nil {
			return nil, err
		}
	}

	// Delete old messages over messageCap
	if mb.store.messageCap > 0 {
		for len(mb.messages) >= mb.store.messageCap {
			log.LogInfo("Mailbox %q over configured message cap", mb.name)
			if err := mb.messages[0].Delete(); err != nil {
				return nil, err
			}
		}
	}

	date := time.Now()
	id := generateId(date)
	return &FileMessage{mailbox: mb, Fid: id, Fdate: date, writable: true}, nil
}

/* Session flow:
 *  1. Send initial greeting
 *  2. Receive cmd
 *  3. If good cmd, respond, optionally change state
 *  4. If bad cmd, respond error
 *  5. Goto 2
 */
func (s *Server) startSession(id int, conn net.Conn) {
	log.LogInfo("POP3 connection from %v, starting session <%v>", conn.RemoteAddr(), id)
	//expConnectsCurrent.Add(1)
	defer func() {
		conn.Close()
		s.waitgroup.Done()
		//expConnectsCurrent.Add(-1)
	}()

	ses := NewSession(s, id, conn)
	ses.send(fmt.Sprintf("+OK Inbucket POP3 server ready <%v.%[email protected]%v>", os.Getpid(),
		time.Now().Unix(), s.domain))

	// This is our command reading loop
	for ses.state != QUIT && ses.sendError == nil {
		line, err := ses.readLine()
		if err == nil {
			if cmd, arg, ok := ses.parseCmd(line); ok {
				// Check against valid SMTP commands
				if cmd == "" {
					ses.send("-ERR Speak up")
					continue
				}
				if !commands[cmd] {
					ses.send(fmt.Sprintf("-ERR Syntax error, %v command unrecognized", cmd))
					ses.logWarn("Unrecognized command: %v", cmd)
					continue
				}

				// Commands we handle in any state
				switch cmd {
				case "CAPA":
					// List our capabilities per RFC2449
					ses.send("+OK Capability list follows")
					ses.send("TOP")
					ses.send("USER")
					ses.send("UIDL")
					ses.send("IMPLEMENTATION Inbucket")
					ses.send(".")
					continue
				}

				// Send command to handler for current state
				switch ses.state {
				case AUTHORIZATION:
					ses.authorizationHandler(cmd, arg)
					continue
				case TRANSACTION:
					ses.transactionHandler(cmd, arg)
					continue
				}
				ses.logError("Session entered unexpected state %v", ses.state)
				break
			} else {
				ses.send("-ERR Syntax error, command garbled")
			}
		} else {
			// readLine() returned an error
			if err == io.EOF {
				switch ses.state {
				case AUTHORIZATION:
					// EOF is common here
					ses.logInfo("Client closed connection (state %v)", ses.state)
				default:
					ses.logWarn("Got EOF while in state %v", ses.state)
				}
				break
			}
			// not an EOF
			ses.logWarn("Connection error: %v", err)
			if netErr, ok := err.(net.Error); ok {
				if netErr.Timeout() {
					ses.send("-ERR Idle timeout, bye bye")
					break
				}
			}
			ses.send("-ERR Connection error, sorry")
			break
		}
	}
	if ses.sendError != nil {
		ses.logWarn("Network send error: %v", ses.sendError)
	}
	ses.logInfo("Closing connection")
}

func (ses *Session) logInfo(msg string, args ...interface{}) {
	log.LogInfo("POP3[%v]<%v> %v", ses.remoteHost, ses.id, fmt.Sprintf(msg, args...))
}

/* Session flow:
 *  1. Send initial greeting
 *  2. Receive cmd
 *  3. If good cmd, respond, optionally change state
 *  4. If bad cmd, respond error
 *  5. Goto 2
 */
func (s *Server) startSession(id int, conn net.Conn) {
	log.LogInfo("SMTP Connection from %v, starting session <%v>", conn.RemoteAddr(), id)
	expConnectsCurrent.Add(1)
	defer func() {
		conn.Close()
		s.waitgroup.Done()
		expConnectsCurrent.Add(-1)
	}()

	ss := NewSession(s, id, conn)
	ss.greet()

	// This is our command reading loop
	for ss.state != QUIT && ss.sendError == nil {
		if ss.state == DATA {
			// Special case, does not use SMTP command format
			ss.dataHandler()
			continue
		}
		line, err := ss.readLine()
		if err == nil {
			if cmd, arg, ok := ss.parseCmd(line); ok {
				// Check against valid SMTP commands
				if cmd == "" {
					ss.send("500 Speak up")
					continue
				}
				if !commands[cmd] {
					ss.send(fmt.Sprintf("500 Syntax error, %v command unrecognized", cmd))
					ss.logWarn("Unrecognized command: %v", cmd)
					continue
				}

				// Commands we handle in any state
				switch cmd {
				case "SEND", "SOML", "SAML", "EXPN", "HELP", "TURN":
					// These commands are not implemented in any state
					ss.send(fmt.Sprintf("502 %v command not implemented", cmd))
					ss.logWarn("Command %v not implemented by Inbucket", cmd)
					continue
				case "VRFY":
					ss.send("252 Cannot VRFY user, but will accept message")
					continue
				case "NOOP":
					ss.send("250 I have sucessfully done nothing")
					continue
				case "RSET":
					// Reset session
					ss.logTrace("Resetting session state on RSET request")
					ss.reset()
					ss.send("250 Session reset")
					continue
				case "QUIT":
					ss.send("221 Goodnight and good luck")
					ss.enterState(QUIT)
					continue
				}

				// Send command to handler for current state
				switch ss.state {
				case GREET:
					ss.greetHandler(cmd, arg)
					continue
				case READY:
					ss.readyHandler(cmd, arg)
					continue
				case MAIL:
					ss.mailHandler(cmd, arg)
					continue
				}
				ss.logError("Session entered unexpected state %v", ss.state)
				break
			} else {
				ss.send("500 Syntax error, command garbled")
			}
		} else {
			// readLine() returned an error
			if err == io.EOF {
				switch ss.state {
				case GREET, READY:
					// EOF is common here
					ss.logInfo("Client closed connection (state %v)", ss.state)
				default:
					ss.logWarn("Got EOF while in state %v", ss.state)
				}
				break
			}
			// not an EOF
			ss.logWarn("Connection error: %v", err)
			if netErr, ok := err.(net.Error); ok {
				if netErr.Timeout() {
					ss.send("221 Idle timeout, bye bye")
					break
//.........这里部分代码省略.........

func main() {
	config.VERSION = VERSION
	config.BUILD_DATE = BUILD_DATE

	flag.Parse()
	if *help {
		flag.Usage()
		return
	}

	// Load & Parse config
	if flag.NArg() != 1 {
		flag.Usage()
		os.Exit(1)
	}
	err := config.LoadConfig(flag.Arg(0))
	if err != nil {
		fmt.Fprintf(os.Stderr, "Failed to parse config: %v\n", err)
		os.Exit(1)
	}

	// Setup signal handler
	sigChan := make(chan os.Signal)
	signal.Notify(sigChan, syscall.SIGHUP, syscall.SIGTERM)
	go signalProcessor(sigChan)

	// Configure logging, close std* fds
	level, _ := config.Config.String("logging", "level")
	log.SetLogLevel(level)

	if *logfile != "stderr" {
		// stderr is the go logging default
		if *logfile == "stdout" {
			// set to stdout
			golog.SetOutput(os.Stdout)
		} else {
			err = openLogFile()
			if err != nil {
				fmt.Fprintf(os.Stderr, "%v", err)
				os.Exit(1)
			}
			defer closeLogFile()

			// close std* streams
			os.Stdout.Close()
			os.Stderr.Close() // Warning: this will hide panic() output
			os.Stdin.Close()
			os.Stdout = logf
			os.Stderr = logf
		}
	}

	log.LogInfo("Inbucket %v (%v) starting...", config.VERSION, config.BUILD_DATE)

	// Write pidfile if requested
	// TODO: Probably supposed to remove pidfile during shutdown
	if *pidfile != "none" {
		pidf, err := os.Create(*pidfile)
		if err != nil {
			log.LogError("Failed to create %v: %v", *pidfile, err)
			os.Exit(1)
		}
		defer pidf.Close()
		fmt.Fprintf(pidf, "%v\n", os.Getpid())
	}

	// Grab our datastore
	ds := smtpd.DefaultFileDataStore()

	// Start HTTP server
	web.Initialize(config.GetWebConfig(), ds)
	go web.Start()

	// Start POP3 server
	pop3Server = pop3d.New()
	go pop3Server.Start()

	// Startup SMTP server, block until it exits
	smtpServer = smtpd.NewSmtpServer(config.GetSmtpConfig(), ds)
	smtpServer.Start()

	// Wait for active connections to finish
	smtpServer.Drain()
	pop3Server.Drain()
}