smtp/server.go

   1 package smtp
   2
   3 import (
   4         "crypto/tls"
   5         "fmt"
   6         "io"
   7         "net"
   8         "net/mail"
   9         "strings"
  10         "time"
  11 )
  12
  13 type ReplyLine struct {
  14         Code    int
  15         Message string
  16 }
  17
  18 func (l ReplyLine) String() string {
  19         return fmt.Sprintf("%d %s", l.Code, l.Message)
  20 }
  21
  22 var (
  23         ReplyOK          = ReplyLine{250, "OK"}
  24         ReplyBadSyntax   = ReplyLine{501, "syntax error"}
  25         ReplyBadSequence = ReplyLine{503, "bad sequence of commands"}
  26         ReplyBadMailbox  = ReplyLine{550, "mailbox unavailable"}
  27 )
  28
  29 func DomainForAddress(addr mail.Address) string {
  30         domainIdx := strings.LastIndex(addr.Address, "@")
  31         if domainIdx == -1 {
  32                 return ""
  33         }
  34         return addr.Address[domainIdx+1:]
  35 }
  36
  37 type Envelope struct {
  38         RemoteAddr net.Addr
  39         EHLO       string
  40         MailFrom   mail.Address
  41         RcptTo     []mail.Address
  42         Data       []byte
  43         Received   time.Time
  44         ID         string
  45 }
  46
  47 func WriteEnvelopeForDelivery(w io.Writer, e Envelope) {
  48         fmt.Fprintf(w, "Delivered-To: <%s>\r\n", e.RcptTo[0].Address)
  49         fmt.Fprintf(w, "Return-Path: <%s>\r\n", e.MailFrom.Address)
  50         w.Write(e.Data)
  51 }
  52
  53 type Server interface {
  54         Name() string
  55         TLSConfig() *tls.Config
  56         VerifyAddress(mail.Address) ReplyLine
  57         // Verify that the authc+passwd identity can send mail as authz.
  58         Authenticate(authz, authc, passwd string) bool
  59         OnMessageDelivered(Envelope) *ReplyLine
  60 }
  61
  62 type EmptyServerCallbacks struct{}
  63
  64 func (*EmptyServerCallbacks) TLSConfig() *tls.Config {
  65         return nil
  66 }
  67
  68 func (*EmptyServerCallbacks) VerifyAddress(mail.Address) ReplyLine {
  69         return ReplyOK
  70 }
  71
  72 func (*EmptyServerCallbacks) Authenticate(authz, authc, passwd string) bool {
  73         return false
  74 }
  75
  76 func (*EmptyServerCallbacks) OnMessageDelivered(Envelope) *ReplyLine {
  77         return nil
  78 }