lint fixes

smtp/client.go

@@ -11,7 +11,7 @@ import (
 )
 
 type MailSender interface {
-	Send(from string, to string, data string) error
+	Send(from, to, data string) error
 }
 
 // SMTP client
@@ -28,7 +28,7 @@ func newClient(cfg *RelayConfig, log *zerolog.Logger) *Client {
 }
 
 // Send email
-func (c Client) Send(from string, to string, data string) error {
+func (c Client) Send(from, to, data string) error {
 	c.log.Debug().Str("from", from).Str("to", to).Msg("sending email")
 
 	var conn *smtp.Client
@@ -67,7 +67,7 @@ func (c Client) Send(from string, to string, data string) error {
 }
 
 // createDirectClient connects directly to the provided smtp host
-func (c *Client) createDirectClient(from string, to string) (*smtp.Client, error) {
+func (c *Client) createDirectClient(from, to string) (*smtp.Client, error) {
 	localname := strings.SplitN(from, "@", 2)[1]
 	target := c.config.Host + ":" + c.config.Port
 	conn, err := smtp.Dial(target)
@@ -81,8 +81,8 @@ func (c *Client) createDirectClient(from string, to string) (*smtp.Client, error
 	}
 
 	if ok, _ := conn.Extension("STARTTLS"); ok {
-		config := &tls.Config{ServerName: c.config.Host}
-		conn.StartTLS(config) //nolint:errcheck // if it doesn't work - we can't do anything anyway
+		config := &tls.Config{ServerName: c.config.Host} //nolint:gosec // it's smtp, even that is too strict sometimes
+		conn.StartTLS(config)                            //nolint:errcheck // if it doesn't work - we can't do anything anyway
 	}
 
 	if c.config.Usename != "" {

smtp/logger.go

@@ -11,24 +11,24 @@ type validatorLoggerWrapper struct {
 	log *zerolog.Logger
 }
 
-func (l validatorLoggerWrapper) Info(msg string, args ...interface{}) {
+func (l validatorLoggerWrapper) Info(msg string, args ...any) {
 	l.log.Info().Msgf(msg, args...)
 }
 
-func (l validatorLoggerWrapper) Error(msg string, args ...interface{}) {
+func (l validatorLoggerWrapper) Error(msg string, args ...any) {
 	l.log.Error().Msgf(msg, args...)
 }
 
 // loggerWrapper is a wrapper around any logger to implement smtp.Logger interface
 type loggerWrapper struct {
-	log func(string, ...interface{})
+	log func(string, ...any)
 }
 
-func (l loggerWrapper) Printf(format string, v ...interface{}) {
+func (l loggerWrapper) Printf(format string, v ...any) {
 	l.log(format, v...)
 }
 
-func (l loggerWrapper) Println(v ...interface{}) {
+func (l loggerWrapper) Println(v ...any) {
 	msg := strings.Repeat("%v ", len(v))
 	l.log(msg, v...)
 }

smtp/manager.go

@@ -90,7 +90,7 @@ func NewManager(cfg *Config) *Manager {
 	}
 
 	s := smtp.NewServer(mailsrv)
-	s.ErrorLog = loggerWrapper{func(s string, i ...interface{}) { cfg.Logger.Error().Msgf(s, i...) }}
+	s.ErrorLog = loggerWrapper{func(s string, i ...any) { cfg.Logger.Error().Msgf(s, i...) }}
 	s.ReadTimeout = 10 * time.Second
 	s.WriteTimeout = 10 * time.Second
 	s.MaxMessageBytes = cfg.MaxSize * 1024 * 1024
@@ -209,7 +209,7 @@ func (m *Manager) loadTLSConfig() bool {
 		return false
 	}
 
-	m.tls.Config = &tls.Config{Certificates: certificates}
+	m.tls.Config = &tls.Config{Certificates: certificates} //nolint:gosec // it's email, even that config is too strict sometimes
 	m.smtp.TLSConfig = m.tls.Config
 	return true
 }

smtp/server.go

@@ -10,17 +10,28 @@ import (
 	"gitlab.com/etke.cc/postmoogle/email"
 )
 
+const (
+	// NoUserCode SMTP code
+	NoUserCode = 550
+	// BannedCode SMTP code
+	BannedCode = 554
+)
+
 var (
+	// NoUserEnhancedCode enhanced SMTP code
+	NoUserEnhancedCode = smtp.EnhancedCode{5, 5, 0}
+	// BannedEnhancedCode enhanced SMTP code
+	BannedEnhancedCode = smtp.EnhancedCode{5, 5, 4}
 	// ErrBanned returned to banned hosts
 	ErrBanned = &smtp.SMTPError{
-		Code:         554,
-		EnhancedCode: smtp.EnhancedCode{5, 5, 4},
+		Code:         BannedCode,
+		EnhancedCode: BannedEnhancedCode,
 		Message:      "please, don't bother me anymore, kupo.",
 	}
 	// ErrNoUser returned when no such mailbox found
 	ErrNoUser = &smtp.SMTPError{
-		Code:         550,
-		EnhancedCode: smtp.EnhancedCode{5, 5, 0},
+		Code:         NoUserCode,
+		EnhancedCode: NoUserEnhancedCode,
 		Message:      "no such user here, kupo.",
 	}
 )

smtp/session.go

@@ -20,6 +20,16 @@ import (
 	"gitlab.com/etke.cc/postmoogle/utils"
 )
 
+// GraylistCode SMTP code
+const GraylistCode = 451
+
+var (
+	// ErrInvalidEmail for invalid emails :)
+	ErrInvalidEmail = errors.New("please, provide valid email address")
+	// GraylistEnhancedCode is GraylistCode in enhanced code notation
+	GraylistEnhancedCode = smtp.EnhancedCode{4, 5, 1}
+)
+
 // incomingSession represents an SMTP-submission session receiving emails from remote servers
 type incomingSession struct {
 	log          *zerolog.Logger
@@ -32,7 +42,7 @@ type incomingSession struct {
 	domains      []string
 	roomID       id.RoomID
 
-	ctx  context.Context
+	ctx  context.Context //nolint:containedctx // that's session
 	addr net.Addr
 	tos  []string
 	from string
@@ -89,13 +99,13 @@ func (s *incomingSession) getAddr(envelope *enmime.Envelope) net.Addr {
 		return s.addr
 	}
 
-	host, portString, _ := net.SplitHostPort(addrHeader) //nolint:errcheck
+	host, portString, _ := net.SplitHostPort(addrHeader) //nolint:errcheck // it is real addr
 	if host == "" {
 		return s.addr
 	}
 
 	var port int
-	port, _ = strconv.Atoi(portString) //nolint:errcheck
+	port, _ = strconv.Atoi(portString) //nolint:errcheck // it's a real addr
 
 	realAddr := &net.TCPAddr{IP: net.ParseIP(host), Port: port}
 	s.log.Info().Str("addr", realAddr.String()).Msg("real address")
@@ -115,7 +125,7 @@ func (s *incomingSession) Data(r io.Reader) error {
 		return err
 	}
 	addr := s.getAddr(envelope)
-	reader.Seek(0, io.SeekStart) //nolint:errcheck
+	reader.Seek(0, io.SeekStart) //nolint:errcheck // becase we're sure that's ok
 	validations := s.getFilters(s.roomID)
 	if !validateIncoming(s.from, s.tos[0], addr, s.log, validations) {
 		s.ban(addr)
@@ -123,8 +133,8 @@ func (s *incomingSession) Data(r io.Reader) error {
 	}
 	if s.greylisted(addr) {
 		return &smtp.SMTPError{
-			Code:         451,
-			EnhancedCode: smtp.EnhancedCode{4, 5, 1},
+			Code:         GraylistCode,
+			EnhancedCode: GraylistEnhancedCode,
 			Message:      "You have been greylisted, try again a bit later.",
 		}
 	}
@@ -164,16 +174,16 @@ type outgoingSession struct {
 	domains   []string
 	getRoomID func(string) (id.RoomID, bool)
 
-	ctx      context.Context
+	ctx      context.Context //nolint:containedctx // that's session
 	tos      []string
 	from     string
 	fromRoom id.RoomID
 }
 
-func (s *outgoingSession) Mail(from string, opts smtp.MailOptions) error {
+func (s *outgoingSession) Mail(from string, _ smtp.MailOptions) error {
 	sentry.GetHubFromContext(s.ctx).Scope().SetTag("from", from)
 	if !email.AddressValid(from) {
-		return errors.New("please, provide email address")
+		return ErrInvalidEmail
 	}
 	hostname := utils.Hostname(from)
 	var domainok bool
@@ -234,7 +244,7 @@ func validateIncoming(from, to string, senderAddr net.Addr, log *zerolog.Logger,
 	case *net.TCPAddr:
 		sender = netaddr.IP
 	default:
-		host, _, _ := net.SplitHostPort(senderAddr.String()) // nolint:errcheck
+		host, _, _ := net.SplitHostPort(senderAddr.String()) //nolint:errcheck // interface constraints
 		sender = net.ParseIP(host)
 	}