Files
proton-bridge/internal/smtp/server.go
2022-05-31 15:54:39 +02:00

124 lines
3.7 KiB
Go

// Copyright (c) 2022 Proton AG
//
// This file is part of Proton Mail Bridge.
//
// Proton Mail Bridge is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Proton Mail Bridge is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Proton Mail Bridge. If not, see <https://www.gnu.org/licenses/>.
package smtp
import (
"crypto/tls"
"fmt"
"io"
"net"
"github.com/ProtonMail/proton-bridge/v2/internal/bridge"
"github.com/ProtonMail/proton-bridge/v2/internal/serverutil"
"github.com/ProtonMail/proton-bridge/v2/pkg/listener"
"github.com/emersion/go-sasl"
goSMTP "github.com/emersion/go-smtp"
)
// Server is Bridge SMTP server implementation.
type Server struct {
panicHandler panicHandler
backend goSMTP.Backend
debug bool
useSSL bool
port int
tls *tls.Config
server *goSMTP.Server
controller serverutil.Controller
}
// NewSMTPServer returns an SMTP server configured with the given options.
func NewSMTPServer(
panicHandler panicHandler,
debug bool, port int, useSSL bool,
tls *tls.Config,
smtpBackend goSMTP.Backend,
eventListener listener.Listener,
) *Server {
server := &Server{
panicHandler: panicHandler,
backend: smtpBackend,
debug: debug,
useSSL: useSSL,
port: port,
tls: tls,
}
server.server = newGoSMTPServer(server)
server.controller = serverutil.NewController(server, eventListener)
return server
}
func newGoSMTPServer(s *Server) *goSMTP.Server {
newSMTP := goSMTP.NewServer(s.backend)
newSMTP.Addr = s.Address()
newSMTP.TLSConfig = s.tls
newSMTP.Domain = bridge.Host
newSMTP.ErrorLog = serverutil.NewServerErrorLogger(serverutil.SMTP)
newSMTP.AllowInsecureAuth = true
newSMTP.MaxLineLength = 1 << 16
newSMTP.EnableAuth(sasl.Login, func(conn *goSMTP.Conn) sasl.Server {
return sasl.NewLoginServer(func(address, password string) error {
user, err := conn.Server().Backend.Login(nil, address, password)
if err != nil {
return err
}
conn.SetSession(user)
return nil
})
})
return newSMTP
}
// ListenAndServe will run server and all monitors.
func (s *Server) ListenAndServe() { s.controller.ListenAndServe() }
// Close turns off server and monitors.
func (s *Server) Close() { s.controller.Close() }
// Implements servertutil.Server interface.
func (Server) Protocol() serverutil.Protocol { return serverutil.SMTP }
func (s *Server) UseSSL() bool { return s.useSSL }
func (s *Server) Address() string { return fmt.Sprintf("%s:%d", bridge.Host, s.port) }
func (s *Server) TLSConfig() *tls.Config { return s.tls }
func (s *Server) HandlePanic() { s.panicHandler.HandlePanic() }
func (s *Server) DebugServer() bool { return s.debug }
func (s *Server) DebugClient() bool { return s.debug }
func (s *Server) SetLoggers(localDebug, remoteDebug io.Writer) { s.server.Debug = localDebug }
func (s *Server) DisconnectUser(address string) {
log.Info("Disconnecting all open SMTP connections for ", address)
s.server.ForEachConn(func(conn *goSMTP.Conn) {
connUser := conn.Session()
if connUser != nil {
if err := conn.Close(); err != nil {
log.WithError(err).Error("Failed to close the connection")
}
}
})
}
func (s *Server) Serve(l net.Listener) error { return s.server.Serve(l) }
func (s *Server) StopServe() error { return s.server.Close() }