banlist

smtp/manager.go

@@ -40,6 +40,8 @@ type Manager struct {
 
 type matrixbot interface {
 	AllowAuth(string, string) bool
+	IsBanned(net.Addr) bool
+	Ban(net.Addr)
 	GetMapping(string) (id.RoomID, bool)
 	GetIFOptions(id.RoomID) utils.IncomingFilteringOptions
 	IncomingEmail(context.Context, *utils.Email) error

smtp/server.go

@@ -23,11 +23,17 @@ type mailServer struct {
 // Login used for outgoing mail submissions only (when you use postmoogle as smtp server in your scripts)
 func (m *mailServer) Login(state *smtp.ConnectionState, username, password string) (smtp.Session, error) {
 	m.log.Debug("Login state=%+v username=%+v", state, username)
+	if m.bot.IsBanned(state.RemoteAddr) {
+		return nil, errors.New("please, don't bother me anymore")
+	}
+
 	if !utils.AddressValid(username) {
+		m.bot.Ban(state.RemoteAddr)
 		return nil, errors.New("please, provide an email address")
 	}
 
 	if !m.bot.AllowAuth(username, password) {
+		m.bot.Ban(state.RemoteAddr)
 		return nil, errors.New("email or password is invalid")
 	}
 
@@ -44,6 +50,10 @@ func (m *mailServer) Login(state *smtp.ConnectionState, username, password strin
 // AnonymousLogin used for incoming mail submissions only
 func (m *mailServer) AnonymousLogin(state *smtp.ConnectionState) (smtp.Session, error) {
 	m.log.Debug("AnonymousLogin state=%+v", state)
+	if m.bot.IsBanned(state.RemoteAddr) {
+		return nil, errors.New("please, don't bother me anymore")
+	}
+
 	return &incomingSession{
 		ctx:          sentry.SetHubOnContext(context.Background(), sentry.CurrentHub().Clone()),
 		getRoomID:    m.bot.GetMapping,
@@ -51,6 +61,7 @@ func (m *mailServer) AnonymousLogin(state *smtp.ConnectionState) (smtp.Session,
 		receiveEmail: m.ReceiveEmail,
 		log:          m.log,
 		domains:      m.domains,
+		addr:         state.RemoteAddr,
 	}, nil
 }
 

smtp/session.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"errors"
 	"io"
+	"net"
 
 	"github.com/emersion/go-smtp"
 	"github.com/getsentry/sentry-go"
@@ -21,9 +22,11 @@ type incomingSession struct {
 	getRoomID    func(string) (id.RoomID, bool)
 	getFilters   func(id.RoomID) utils.IncomingFilteringOptions
 	receiveEmail func(context.Context, *utils.Email) error
+	ban          func(net.Addr)
 	domains      []string
 
 	ctx  context.Context
+	addr net.Addr
 	to   string
 	from string
 }
@@ -31,6 +34,7 @@ type incomingSession struct {
 func (s *incomingSession) Mail(from string, opts smtp.MailOptions) error {
 	sentry.GetHubFromContext(s.ctx).Scope().SetTag("from", from)
 	if !utils.AddressValid(from) {
+		s.ban(s.addr)
 		return errors.New("please, provide email address")
 	}
 	s.from = from
@@ -50,17 +54,20 @@ func (s *incomingSession) Rcpt(to string) error {
 	}
 	if !domainok {
 		s.log.Debug("wrong domain of %s", to)
+		s.ban(s.addr)
 		return smtp.ErrAuthRequired
 	}
 
 	roomID, ok := s.getRoomID(utils.Mailbox(to))
 	if !ok {
 		s.log.Debug("mapping for %s not found", to)
+		s.ban(s.addr)
 		return smtp.ErrAuthRequired
 	}
 
 	validations := s.getFilters(roomID)
 	if !validateEmail(s.from, s.to, s.log, validations) {
+		s.ban(s.addr)
 		return smtp.ErrAuthRequired
 	}