mirror of https://github.com/chylex/SMTP-Relay.git
137 lines
2.9 KiB
Go
137 lines
2.9 KiB
Go
package smtprelay
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import (
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"crypto/tls"
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"fmt"
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"net"
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"os"
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"os/signal"
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"syscall"
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"github.com/chrj/smtpd"
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"github.com/sirupsen/logrus"
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"smtprelay/internal/config"
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"smtprelay/internal/logger"
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"smtprelay/internal/smtp"
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)
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var (
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cfg *config.Config
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log *logrus.Logger
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)
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func Run() {
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if len(os.Args) != 2 {
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fmt.Println("Usage: smtprelay <config_file>")
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os.Exit(1)
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}
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cfg = config.Load(os.Args[1])
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log = logger.SetupLogger(cfg.LogFile, *cfg.LogLevel, *cfg.LogFormat)
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log.Debug("starting smtprelay")
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var servers []*smtpd.Server
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// Create a server for each desired listen address
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for _, listen := range cfg.ListenAddrs {
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server := smtp.CreateRelayServer(cfg, log)
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listener := createListener(log.WithField("address", listen.Address), listen, server)
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servers = append(servers, server)
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go func() {
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server.Serve(listener)
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}()
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}
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handleSignals()
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// First close the listeners
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for _, server := range servers {
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shutdownServer(log.WithField("address", server.Address()), server)
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}
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// Then wait for the clients to exit
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for _, server := range servers {
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waitForServer(log.WithField("address", server.Address()), server)
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}
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log.Debug("done")
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}
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func createListener(log *logrus.Entry, listen config.ProtoAddr, server *smtpd.Server) net.Listener {
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var listener net.Listener
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var err error
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switch listen.Protocol {
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case "":
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log.Info("listening on address")
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listener, err = net.Listen("tcp", listen.Address)
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case "starttls":
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server.TLSConfig = getTlsConfig()
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server.ForceTLS = cfg.LocalForceTLS
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log.Info("listening on address (STARTTLS)")
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listener, err = net.Listen("tcp", listen.Address)
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case "tls":
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server.TLSConfig = getTlsConfig()
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log.Info("listening on address (TLS)")
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listener, err = tls.Listen("tcp", listen.Address, server.TLSConfig)
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default:
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log.WithField("protocol", listen.Protocol).Fatal("unknown protocol in listen address")
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return nil
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}
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if err != nil {
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log.WithError(err).Fatal("error starting listener")
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return nil
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}
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return listener
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}
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func getTlsConfig() *tls.Config {
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tlsConfig, err := smtp.GetTlsConfig(cfg.LocalCert, cfg.LocalKey)
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if err != nil {
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log.WithFields(
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logrus.Fields{
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"cert_file": *cfg.LocalCert,
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"key_file": *cfg.LocalKey,
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},
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).WithError(err).Fatal("could not set up TLS")
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}
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return tlsConfig
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}
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func handleSignals() {
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// Wait for SIGINT, SIGQUIT, or SIGTERM
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sigs := make(chan os.Signal, 1)
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signal.Notify(sigs, syscall.SIGINT, syscall.SIGQUIT, syscall.SIGTERM)
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sig := <-sigs
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log.WithField("signal", sig).
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Info("shutting down in response to received signal")
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}
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func shutdownServer(logger *logrus.Entry, server *smtpd.Server) {
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logger.Debug("Shutting down server")
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err := server.Shutdown(false)
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if err != nil {
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logger.WithError(err).Warning("Shutdown failed")
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}
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}
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func waitForServer(logger *logrus.Entry, server *smtpd.Server) {
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logger.Debug("Waiting for server")
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err := server.Wait()
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if err != nil {
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logger.WithError(err).Warning("Wait failed")
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}
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}
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