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|
package milter
import (
"errors"
"net"
"net/textproto"
)
// Milter protocol version implemented by the server.
//
// Note: Not exported as we might want to support multiple versions
// transparently in the future.
var serverProtocolVersion uint32 = 2
// ErrServerClosed is returned by the Server's Serve method after a call to
// Close.
var ErrServerClosed = errors.New("milter: server closed")
// Milter is an interface for milter callback handlers.
type Milter interface {
// Connect is called to provide SMTP connection data for incoming message.
// Suppress with OptNoConnect.
Connect(host string, family string, port uint16, addr net.IP, m *Modifier) (Response, error)
// Helo is called to process any HELO/EHLO related filters. Suppress with
// OptNoHelo.
Helo(name string, m *Modifier) (Response, error)
// MailFrom is called to process filters on envelope FROM address. Suppress
// with OptNoMailFrom.
MailFrom(from string, m *Modifier) (Response, error)
// RcptTo is called to process filters on envelope TO address. Suppress with
// OptNoRcptTo.
RcptTo(rcptTo string, m *Modifier) (Response, error)
// Header is called once for each header in incoming message. Suppress with
// OptNoHeaders.
Header(name string, value string, m *Modifier) (Response, error)
// Headers is called when all message headers have been processed. Suppress
// with OptNoEOH.
Headers(h textproto.MIMEHeader, m *Modifier) (Response, error)
// BodyChunk is called to process next message body chunk data (up to 64KB
// in size). Suppress with OptNoBody.
BodyChunk(chunk []byte, m *Modifier) (Response, error)
// Body is called at the end of each message. All changes to message's
// content & attributes must be done here.
Body(m *Modifier) (Response, error)
}
// NoOpMilter is a dummy Milter implementation that does nothing.
type NoOpMilter struct{}
var _ Milter = NoOpMilter{}
func (NoOpMilter) Connect(host string, family string, port uint16, addr net.IP, m *Modifier) (Response, error) {
return RespContinue, nil
}
func (NoOpMilter) Helo(name string, m *Modifier) (Response, error) {
return RespContinue, nil
}
func (NoOpMilter) MailFrom(from string, m *Modifier) (Response, error) {
return RespContinue, nil
}
func (NoOpMilter) RcptTo(rcptTo string, m *Modifier) (Response, error) {
return RespContinue, nil
}
func (NoOpMilter) Header(name string, value string, m *Modifier) (Response, error) {
return RespContinue, nil
}
func (NoOpMilter) Headers(h textproto.MIMEHeader, m *Modifier) (Response, error) {
return RespContinue, nil
}
func (NoOpMilter) BodyChunk(chunk []byte, m *Modifier) (Response, error) {
return RespContinue, nil
}
func (NoOpMilter) Body(m *Modifier) (Response, error) {
return RespAccept, nil
}
// Server is a milter server.
type Server struct {
NewMilter func() Milter
Actions OptAction
Protocol OptProtocol
listeners []net.Listener
closed bool
}
// Serve starts the server.
func (s *Server) Serve(ln net.Listener) error {
defer ln.Close()
s.listeners = append(s.listeners, ln)
for {
conn, err := ln.Accept()
if err != nil {
if s.closed {
return ErrServerClosed
}
return err
}
session := milterSession{
server: s,
actions: s.Actions,
protocol: s.Protocol,
conn: conn,
backend: s.NewMilter(),
}
go session.HandleMilterCommands()
}
}
func (s *Server) Close() error {
s.closed = true
for _, ln := range s.listeners {
if err := ln.Close(); err != nil {
return err
}
}
return nil
}
|
